Lit''

.-y ^-^

HARVARD UNIVERSITY

LIBRARY

OF THE
MUSEUM OF COMPARATIVE ZOOLOGY

GIFT OF
Linnean Soc. London.

1889

THE

TRANSACTIONS

or

THE LINNEAN SOCIETY

OF

LONDON.

SECOND SERIES— VOLUME IV.
ZOOLOGY.

LONDON:

I'RINTKD BY TAYLOR AND FRANCIS, BED LION COURT, FLEET STREET

ISOLD AT TUE SOCIETY'S APAKTMEXTS, BURLINGTON HOUSE;
AM) l',\ LONGMANS, GREEN, AND CO., I'ATERNOS I'EK-UOW.

1880-88.

CONTENTS.

A Mono(jr(ipli of Recent Brachiopoda. By Thomas Davidson, LL.B., F.R.S., F.L.S.

Issued in three parts as folloAvs : —

Part I., pp. 1-74, & Plates I.-XIII., published October 188C.

„ II., „ 75-182, „ XIV.-XXV., „ July 1887.

„ III., „ 183-218,
Titlepage, Couteuts, &c.

I „ XXVI.-XXX., „ October 188S.

NOTE. — At the request of the late Dr. Davidson, and with the sanction of the Council,
the proof-sheets of this Memoir have been laid before Miss Agnes Crane, of Brigliton,
by whom they have been read on the Author's behalf.

Previous to Dr. Davidson's lamented death, Miss Crane had Ijeen studying- the
Brachiopoda under his guidance, and was conversant with his wishes respecting the
publication of this work.

TRANSACTIONS

OP

THE LINNEAN SOCIETY.

I. A Monograph of Recent BracJdopoda. — Part I.
By Thomas Davidson, LZ.B., F.E.S., F.L.S., F.G.S., Sfc.

Eead 5th November, 1885.

(Plates I.-XIII.)

Introductory Remarks.

DUEING the last hundred years the recent Brachiopoda have attracted considerable
attention, and a large number of valuable memoirs and papers have been published upon
them. Their shells, shell-structure, anatomy, embryology, and affinities have alike been
carefully investigated. Observations on the living animals of several genera have also
been recorded. The sea-bottoms have been dredged for Brachiopoda in many latitudes
and over a wide geographical area, and their habitats and ranges of depth accurately
ascertained to a very considerable extent. Pour or five incomplete monographs, in
which the shells only of a large number of species have been well illustrated and briefly
described, have appeared during the present century; but no satisfactory general
monograph ti'eating of the shell and animal conjointly has yet been published. This
omission I have now endeavoured to supply.

In 1843, Klister, in his new edition of Chemnitz's ' Conchy lien-Cabinet,' described
some twenty-six or thirty species, of which several are now known to be synonyms.
These he figured in six quarto plates.

In 1846, G. B. Sowerby, in his ' Thesaurus Conchyliorum,' described and beautifully
illustrated forty- seven species, of which number several are synonyms.

In 1859-62, Lovell Eeeve, in his 'Conchyliorum Iconica,' described the shells of seventy-
hve species, of which some w^ere synonyms, accompanied with a series of beautiful
illustrations, drawn by G. B. Sowerby.

In 1873, in the ' Proceedings of the Academy of Natural Sciences of Philadelphia,'
Mr. W. H. Dall published a catalogue of all the recent species of Brachiopoda known to

SECOND series. — ZOOLOGY, VOL. IV, 1

2 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

him up to that date. In this catalogue without figures, ahout one hundred species are
enumerated, some of which are synonymous.

During the last thirty-five or more years, I have devoted much time to the study of
the recent forms, in conjunction with that of the fossil species, and have lost no oppor-
tunity of making myself acquainted with all that has been done and written upon the
subject, as well as in assembling all available material, so as to enable me to bring
together in a single monograph the chief results of many independent researches published
in a number of scattered papers and works often difiicult of access. The literature of
the subject is indeed voluminous, as may be realized by a glance at the ' Bibliography
of the Brachiopoda,' compiled by Mr. W. H. Dalton and myself, and published in vol. vi.
of my ' British Fossil Brachiopoda ' (Palfeont. Soc, 1886).

I have also, I believe, had advantages which few have possessed in being able to follow-
out the observations made with respect to the animal and its anatomy, and in having
been able to draw a very large number of figures from the types of the best-preserved
examples of almost all the known forms, as well as of a large series of individuals of
the same species at different stages of development. Tlie study of the adult condition of
a species gives insufficient data, and it is requisite to follow out the modifications it has
to go through during the different stages of its existence, and to note these differences.

The study of the embryo has also shown that the animal assumes a series of well-
defined stages in its development, a fact that was but little known prior to the publi-
cation in 1861 of Prof. Lacaze-Duthiers's admirable memoir on Thecidium medi-
terraneum. These observations were subsequently followed by the excellent
researches of Fritz Muller, Kowalcvsky, E. Morse, II. Friele, M'^Crady, Dall, Van
Bemmelen, A. E. Shipley, M. A. Schulgin, and one or two more. The results
obtained by these authors will be referred to in the sequel. It is very desirable that
these important investigations should be continued, as much still remains to be
discovered, described, and illustrated.

The shell-structure of the recent Brachioiioda has been admirably worked out by a
number of accurate observers, such as Dr. W. B. Carpenter, W. King, Van Bemmelen,
Hancock, and many others, and has led to very important results. To Herman Friele,
E. Deslongcbamps, and one or two others we are indebted for much accurate and im-
portant knowledge with respect to the development of the loop, of which but little was
known previous to 1852.

The anatomy of the animal has also l)een admirably investigated and worked out, and
it is sufficient to mention the names of Cuvier, Owen, Huxley, Hancock, Vogt, Gratiolet,
Lacaze-Duthiers, King, Brooks, Dall, Morse, E. Deslongcbamps, Van Bemmelen, Wood-
ward, Shipley, Schulgin *, and others, to show how important and varied have
been the additions to our knowledge with respect to this very necessary branch of
investigation. In drawing up the description of each species, I have considered it
desirable, whenever possible, to reproduce the words and illustrations of the authors, and
thus give them all credit for their careful, painstaking researches.

* To these names Dr. Davidson would doubtless have added that of H. G. Be3-er, who contributed an important
paper on the shell-structure and anatomy of Lmr/ida {Glottidia) pyramidata, Stimpson, to the Studies from the
Biological Laboratory of the Johns Hopkins University, Baltimore, vol. iii. no. 5, March 188(3. — [xi. C]

DR. T. DAVIDSON ON EECENT BRACIIIOPODA. 3

The perplexing question of the affinities of the Brachiopoda has given rise to mucli
discussion, and great difference of opinion, especially \yith regard to their relationship
to the group of worms. Now, although I do not admit the Brachiopoda to be worms,
they may, as well as the Mollusca and some other groups of invertebrates, have originally
diverged from an ancestral vermiform stem, sucb as the remarkable worm-like mollusk
Neomenia Avould denote. In a recent paper on the development of Arylope or Cistella,
Mr. A. E. Shipley observes, and, I think, with justice, that the Brachiopoda and Polyzoa
are not so closely united as to form a natural phylum ; and he adds, " I should propose
to follow Gegenbaur in making a primary class of the Brachiopoda, and though in their
development and adult structure they are widely separated from botli Vermes and
Mollusca, of the two classes I would place them nearer to the former class than to the
latter " *. Prof. Huxley f says : — " All known Polyzoa are compound animals, that is to
say, the product of every ovum gives rise, by gemmation, to great assemblages of partially
independent organisms, or zooids. The Brachiopoda, on the contrary, are all simple, the
product of each ovum not giving rise to others by gemmation. All the Brachiopoda
possess a bivalve sliell — a shell composed of two, more or less horny, or calcified, pieces,
whicb are capable of a certain range of motion on one another, and are very commonly
articulated together by teeth and sockets." The shell, the pallial lobes, the intestine, the
nerves, and the atrial system, afford characters amply sufficient to define the class.

In this view of Prof. Huxley I entirely concur.

As many species of Brachiopoda live at considerable depths, it is not surprising that
so small a number should have been known to early conchologists, and that for many
years they should have been such groat rarities in conchological collections. The
numerous well-conducted dredging expeditions have, however, brought to light a large
number of forms that were not previously known, and we may constantly expect to add
to the number of species as dredging operations extend to regions not yet explored.
It has been ascertained beyond doubt that Brachiopoda are much localized, and that
where they occur they are generally abundant. It has also been found that the
range in depth of one and the same species is often very variable, that abyssal forms
have generally a very thin shell, and that species living at a great depth have a much
greater geographical range, and are not nearly so localized as those species that live
in shallow waters.

The study of the species brought home by the ' Challenger ' Expedition, which I was
privileged to examine and describe, has revealed much valuable information with respect
to the Ijathymetrical and geographical distribution of many species. The greatest depth
at which a recent species of the class has been found alive was 2900 fathoms. A
number of forms inhabit and prefer rocky and stony parts of the bottom, or are attached
to corals, and are tlierefore more difficult to obtain.

It is necessary briefly to refer to the difficult question of classification, upon which
many different opinions have been entertained. In company with a larger number of

* •' On the Structure and Development of Arr/iojje." Mittheilungen aua der zool. Station zu Neapel, Band iv.
Heft 4, p. 516 (1883).

t An Introduction to the Classification of Animals, p. 27 (18G9).

DE. T. DAVIDSON ON RECENT BRACHIOPODA.

malacologists and palaeontologists, I have considered the interior skeleton that supports
the labial appendages as a classiflcatory character that could be advantageously made
use of, and have consequently grouped the recent species into the two great divisions
Arthropomata, Owen { = Clistenterata, King), and Lyopomata, Ovfen {^= Tretenterata,
King), and into six families, as follows :

Akthropomata., Owen= Clistenterata, King.

1st Family
TEREBEA-
TULIDJE.

Subfamily TerebratulinjK

I. Genus Lioihyris, Douville

II. Subgenus Terebratidina, d'Orbigny
III. Genus Waldheimia, King

Subfamily Teeebrateixin^

Subfamily Megerlin^

Subfamily Magasin^

Subfamily Kraussinin^ . . .

IV. Genus Terehratella, d'Orbigny
V. Subgenus MagaseJla, Dall. . . .

VI. Genus Megerlia, King

VII. Subgenus Laqueus, Dall . . .

VIII. Genus Bouchardia, Davidson

secies.
8

species.
2

10

5

10

1

9

3

6

6

•■>

1

3

1

Subfamily AEGiopiNiE

IX. Genus Kraussina, Davidson.

X. Subgenus Mer/erlina, Deslongchamps.

XI. Genus Arriio]ie, Deslongchamps ....

XII. Subgenus Cistella, Gray

2?
1

L

Subfamily not yet determined.

2nd Family THECIDIID.E

XIII. ? Giuynia, King . .

XIV. Genus Platydia, Costa ....

XV. Genus TheckUum, Defiance

.) J T^ 1 T>TT1'^^T/-,TTf^-lTT^TTTT. TT. f XVI. Geuus Rhytichonella, FischeT

3rd Family EHl NCHOXELLID^ i , ^

I XVII. Subgenus Atrctia, Jeffreys . .

Jeffreys

Lyopomata, Owen=: Treienterata, King.

4th Family CRANIID.^ XVIII. Genus Crania, Retzius .

5th Family DISCINID^

{XIX. Genus Discina, Lamarck .
XX. Subgenus Discinisca, Dall

6th FamUy LINGULID^ | ^^^- ^'""' ^'"5'"^«' Bruguiere

I XXII. Subgenus Olottidia, Dall .

In 1884, M. E. E. Deslongchamps proposed a new scheme of classification for the
Terebratulidse, in which he objected to any arrangement based on either the extci-ior
shape of the shell or of the supports of the labial appendage.

His first group includes the different forms in which the calcified brachial apparatus
or loop does not undergo any important modifications from its first origin up to the
adult condition. To the characters drawn from the brachial apparatus or loop is added
tliat of the presence of spicula, more or less complicated, which occupy in the mantle
all the parts connected with the organs of circulation (arteries, veins or veiny sinuses,
&c.), the labial appendages and cirri whicli accompany them. In this group he places
the recent genera Liothyris, TerebratuUna, ^legerlia, Kraussina, and FlatycUa.

DR. T. DAVIDSON OX RECENT BRACHIOPODA. 5

lu his second group he unites those forms in which the brachial apparatus or loop
undergoes numerous transformations from the embryo up to the adult condition, and
which have been distinguished by the names of Platydiform, Magadiform, and Megerli
form stages. The mantle in this group is not provided with those calcareous spicuhi
which occur so constantly in the first grovip. The colour also of the dried animal is
yellowish, whilst in the first group the hue or tint of the dried arms and of the peri-
pheric portions of the mantle are of a very clxaracteristic dim white. This, I may,
however, remark, is not always the case, as I possess specimens of the dried animal of
several species of TerebratuUna that are of a decided yellow colour. The group would,
according to M. Deslongchamps, comprise the recent genera Waldheimia, Macandrevia,
TerebrateUa, Laqueus, and Magasella.

While fully appreciating the importance of all characters derived from a study of the
animal, I am not convinced that the temporary modifications in the shape of the loop,
or tlie presence or absence of calcareous spicula in the mantle, &c., are indications of
sufScient importance or permanence to supersede those derived from the adult shape of
the calcareous lamellae supporting the labial appendages, — characters which are often
accessible, and of important assistance in distinguishing the moi*e numerous fossil
members of the group. Moreover, Mr. W. H. Dall, in describing the animal of Wald-
heimia floridana (Bull. Mus. Comp. Zool. Harvard, vol. iii. p. 16, 1871), distinctlv notes
the existence of a few exceedingly delicate spicula in the floor of the great sinuses. It
would seem therefore that these spicula occur in a genus which M. E. E. Deslongchamps,
in his proposed new classification of the Terebratulidae, places among those forms charac-
terized by the entire absence of spicula.

After long and searching examinations of the recent forms, I have described in this
monograph about one hundred so-termed species, some varieties, and about twenty-
eight uncertain ones. Of course the vexed question as to what really constitutes a
species remains the same, and is likely to remain so for a long time to come.

It will not be necessary to extend these introductory remarks, as all details have been
fully given under each species. In conclusion I would tender my grateful thanks to the
many kind friends who have in so zealous a manner supplied me \\\t\\ valuable infor-
mation and specimens *.

AETIIROPOMATA, 0\veu=CLISTENTERATA, King.
Family TEREBRATULID^, (Gray) emend. Davidson.

Subfamily Tbrebkatulin^, Dall, 1870.

During the last few years a strong desire has been manifested by those palaeontologists
who consider an extreme subdivision of genera desirable, to separate from Terehratnla
proper those forms characterized by a small short loop, of which the principal stems are
united anteriorly by a slightly arched lamella, and of which Liothyris vitrea may bi-
taken as the type.

* The drawings for tho Plates were made by myself, on paper: but the state of my health would not allow of my
reproducing them on stone.

6 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

As there are certainly some differences observable in the two groups, and as none of
the recent species would agree in the characters of their loops and in certain other
particulars with the forms referred to the genus Terebratula of Llhwyd and Klein, it
may perhaps be better to adopt Douville's generic name Liothyris for the species we are
about to describe.

In the larger number of the recent species, sucli as in Liothyris vitrea, L. arctica,
L. Moseleyi, L. tiva, L. Bartletti, L. WyvilUi, and L. suhqnadruta, the connecting band of
the loop is narrow, while in L. splicBnoidea—cubensis it is larger.

The specific claims of Liothyris cernica, and L.? DalU are still uncertain, only a single
example of each of them having been hitherto discovered.

Very small, or scarcely any modifications in the shape of the loop have been observed ;
all the species have their shell minutely perforated l)y canals, and calcareous spicules are
abundant in the mantle.

1. Liothyris vitrea, Born, sp. (Plate I. figs. 1-12.)

Anomia vitrea, Bora, Testacea Musei Caes. p. 119, vignette, 1778; Linn^, ed. Gmelin, p. 3347,
1788.

Gnjphus vitrea, Megerle v. Miihlfeld, Berliu Mus. 1811.

Terebratula vitrea, Lamarck, An. sans Vert. vol. vii. p. 245, 1819; Payraudeau, Cat. p. 83, no. 160,
1826; G. Bronn, Italicus Tertiar-Gebilde, p. 125, 1831; Pliilippi, Enum. Moll. Sicilise, vol. i. p. 95,
t. 6. figs. 6-8, 1836, vol. ii. p. 66, 1844; A. Scacclii, Cat. Couch. Regni Neapolitaui, p. 8, 1836;
Kiister, Martini & Chemnitz, Conch. -Cab. vol. vii. p. 22, tab. 2. figs. 11-13, 1843; E. Forbes, Report
on the Mollusca of the Mgenn Sea, Brit. Assoc. Report, p. 141, 1843; D. Galvani, Illustrazione
delle Conch. Foss. 1845 ; G. B. Sowerby, Thes. Conch, vol. i. p. 353, pi. 70. figs. 56-59, 1846 ; Aradas
(pars) Conchiglie fossili di Gravatelli, p. 14, 1851 ; O. G. Costa, Fauna del regno di Napoli, p. 33,
pi. i. figs. 1-3, 1851-52; Davidson, Sketch of a Class, of recent Brachiopoda, Ann. & Mag. Nat. Hist,
vol. ix. p. 364, 1852, and Br. Foss. Brach. Pal. Soc. vol. i.. Introduction, p. 62, fig. 23, and pi. vi. 1852;
S. P. Woodward, Manual of Mollusca, p. 215, 1856; L. Reeve, Conch. Icon. pi. 3. fig. 8, 1860, and
Journ. de Conch, vol. ix. p. 124, 1861 ; Chenu, Man. de Couch, vol. ii. p. 201, 1862 ; Segucnza, Atti
della Soc. Italiana di Scienze Nat. vol. i. p. 17, pi. 1. figs. 1-7, 1865; H. C. Weiukauft', Die Conch.
Mittelmeeres, vol. i. p. 284, 1867 ; Davidson, Italian Tert. Brach., Ann. & Mag. Nat. Hist. vol. vii.
pi. xvii. fig. 11, 1870; Jeflreys, Ann. & Mag. Nat. Hist. 5th ser. vol. x. p. 28, 1882.

Liothyris vitrea, Douville, Bull. Soc. Geol. de France, 3'' ser. vol. vii. 1879 ; E. Deslongchamps, Note
sur la Classification des Terebratules, ou Etudes critiques sur les Brachiopodes, pp. 106 & 153, pi. xx.
figs. 7-11, 1884.

Shell longitudinally oval or ovate, globose, widest about the middle, laterally rounded
or more or less pinched in near the front, front margin nearly straight or gently
rounded. Colour nearly white, surface smooth, semitransparent, glassy, marked with
fine concentric lines of growth and perforated by minute canals. Dorsal valve tumidly
convex, longitudinally flattened along the middle, from which the anterior lateral portions
slope to the edge. Venti-al valve slightly deeper than the dorsal one, longitudinally
flattened along the middle ; beak incurved, moderately produced and slightly overlying
the umbo of tlie dorsal valve, obliquely truncated l)y a very small circular foramen
with thickened margin and separated from the hinge-line by a small triangular deltidium
in two pieces. Loop in the interior of the dorsal valve simple and short, attached by its

DR. T, DAVIDSON ON RECENT BRACHIOPODA. 7

crura to the hinge-plate and not exceeding a fourth of the length of the valve, the two
principal stems becoming soon united anteriorly by a transverse lamella bent upwards in
the middle ; no mesial septum ; cardinal process small and prominent, hinge-plate
disunited, four diverging grooves extending from under the cardinal process to about
half the length of the valve, tlie central pair being the longest. In the interior of the
ventral valve a similar numl)er of grooves ; muscular impressions small, situated at the
bottom of the valve under the loop and in the rostral portion of the bottom of the ventral
one. Animal attached by a peduncle ; labial appendages united to each other by a
membrane ; brachial disk trilobed ; central lobe elongated and spirally convoluted.
Very delicate spicula form elegant star-like plates in the mantle. Length 1 iucli 8
lines, breadth 1 inch 5 Hues, deptli 1 inch.

Hab. Abuudant in the Mediterranean iu depths of from 90 to 250 fathoms. Very
numerous in the Bay of Naples at depths of from 100 to 300 metres. Vigo Bay, 40
fathoms (M" Andrew^) . Dredged by Prof. Giglioli, during the Italian Expedition to the
Mediterranean in 1881, at a depth of 800 fathoms (see report in the Atti del iii.
Congresso Geografico Internaziouale). Also for distribution of this and other species, see
Jeffreys's papers " On the Mollusca of the ' Lightning ' and ' Porcupine ' Expeditions,"
Proc. Zool. Soc. Loud. 1878, 1879, 1881, 1882.

Ohs. Liolliyris citrea is a beautiful, well-known, and abundant Mediterranean species.
It varies considerably in its relative length, breadth, and degree of convexity ; some
specimens being quite elongated oval, 1 inch 8 lines in length by 1 inch 1 line in breadth,
while other examples of the same length would have a breadth of 1 inch and 3 or i< lines ;
some are much more pinched iu anteriorly than others, and, lastly, some are nearly
circular with an equal length and breadth.

Prof. E. Deslongchamps, in bis instructive memoir on the classitication of the Tere-
bratulidfE, gives us the result of his studies in connection with the embryo of L. vitrea,
as well as of its subsequent stages of development. He states, " I have been able to
examine the embryo at two millimetres of size, tliat is to say from the first moments
when the larval condition has ended and the shell has begun to be formed ; its shape is
then absolutely similar to that of the young of Terehratidina ; the dorsal valve is rounded,
and slightly convex ; the ventral one shows a triangular hole, of which tlie summit,
which does not yet show any trace of a notch, will eventually become the beak. Xo
trace of a deltidium is to be seen on the sides of this foramen. On opening this little
shell, one is at once struck by the dull white of the internal walls ; and, by the aid of a
lens, one recognizes granulous parts affecting a certain regularity. The same dull white
condition is seen on the fragments of the labial appendages that have remained adhering
to them, hiding to some extent the brachial appendages. On examination of these frag-
mentary labial appendages with an enlargement of 20 to 30 diameters, one immediately
observes calcareous spicula, the sharp extremities of which form a most elegant border,
encroaching on the brachial membrane. These spicula were formed therefore from tlie
beginning of the formation of the shell and, already very complicated, entirely resemble

those seen in the adult individual The cirri and the channel of the laijial

appendages are enveloped by a layer of spicula spread out on the interbracliial

8 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

membraue in a sort of border or festoon Having afterwards submitted the

minute shell to the action of water, accompanied by a little caustic potash, I was
able to isolate the brachial appendages without effecting any fracture. The calcareous
appendage, or loop, is formed at this stage of growth by two little short calcareous
processes only, which represent the origin of the crura and offer no traces either of the
principal stems or of the transverse connecting lamina of the loop. In this first stage,
the brachial appendages entirely resemble those of a Bhynchonella ; and if one limited
oneself to a superficial examination one would be more disposed to take the embryo of
Liothyris vitrea for a minute Rhynclionella, the then triangular aspect of the foramen

and the pointed beak heightening the illusion I next examined diffei'ent

examples of 6 and 7 millimetres in length ; the shell then, although still quite young, had
completely changed in aspect, its shape being essentially the same as in the adult condition.

The loop occupies about a fourth of the length of the shell, and is complete in all

its parts. I next examined specimens of 10 millimetres in length, in which the only
differences, and very sliglit ones, were limited to the loop being a little broader ante-
riorly, and it never afterwards assumed any difference Therefore the study

of Liothyris vitrea offers three facts of great general importance, namely : —

" 1. The brachial apparatus or loop follows in its development a regular progression.
It is at first as simple as possible, composed of two little branches which unite after-
wards so as to form a small apparatus in the shape of a crest.

" 2. This apparatus once formed does not undergo any metamorphosis, and does not pass
thi'ough the complications that one observes in Terebratella.

" 3. As soon as the labial appendages or arms have developed themselves, and the
brachial apparatus or loop has commenced to be formed, the mantle and the arms present
in the interior a very complicated system of calcareous spicula, especially destined to
protect the channel of circulation, whilst in the Terchratutcs with long loops, JFaldheimice,
and Terebratellce, one can discover not a trace of similar spicula."

The soft parts of the animal of Liothyris vitrea are very similar to those of Tere-
hratulina caput-serpentis, to which we allude in the sequel.

It is to be regretted that the anatomy of L. vitrea has not yet been published, and
still remains a desideratum. The intimate shell-structure of L. vitrea has been minutely
described and illustrated by Van Bemmelen in his memoir on the anatomy of the
Brachiopoda * ; tlie circular perforations, or canals, are widely separated from each other
(as may be seen in the figure) although very small on the surface of the shell itself.
Malformations in L. vitrea are not common. M. E. Deslongchamps has, however,
described and illustrated a very remarkable one (Plate I. fig. 10 of this work) in which
there exists a large longitudinal septum in both valves, which has been caused by an
accident similar to that which caused the formation of the hole in Terebratula diphya.

Liothyris vitrea is a common fossil in the Pliocene rocks of Sicily, and occm's at
Trapani, Tremonte, Gravitelli, and also at Terreti, near Eeggio, in Calabria.

The shell referred to L. vitrea, by Chemnitz, in his Neues Conch. Cab. p. 97, tab. 78,

* Over den Bouw der SchcIpeiJ van Bracbiopoden en Cliitoucn, 18S2.

mi. T. DAVIDSON ON EECENT BRACHIOPODA. 9

fig. 707, 1785, cannot surely belong to Bern's species, for he figures in it a longitudinal
septum, Avhich never occurs in that species.

Several varieties of Z. v'ltrea have received distinctive names.

LiOTHYRis viTREA, var. MINOR, Philippi. (Plate I. fig. 13.)

Terebratula ritrea, var. minor, Tliilippi, Enuracratio Moll. Siciliffi, vol. i. p. 99, pi. vi. fig. 8, 183G ; vol. ii.
p. (](), 1814..

Terebratula affinis, Calcara, Ceimo sui Mollusclii viventi c fossili di Sicilia, p. 48, 1845.

Terebratula vitrea (pars), A. Aradas, Descrizione dclle concliiglie fossili di Gravatelli presso INIessiua,
p. 14, 1847.

Terebratula minor, E. Suess, Ueber die Wohnsitze der Brachiopoden, 1859; Davidson, On recent
Terebratula;, Ann. & ]Mag. Nat. Hist. 3rd ser. vol. viii. p. 35, 18fil.

Terebratula affinis, G. Seguenza, Notizie succinte intorno etc. pp. 19, 2G, 32, 1862 ; id. Sulla
formazionc mioc. di Sicilia etc. p. 7, 1862.

Terebratula minor, Davidson, Outline of the Geology of the Maltese Islands by Dr. Leith Adams ;
and Description of the Brachiopoda by Thos. Davidson, Ann. & Mag. Nat. Hist. 3rd ser. vol. xiv.
p. 8, pi. i. fig. 8, 1864; Seguenza, Memorie della See. Ital. di Scieuze Naturali, vol. i. p. 21, 1865;
Kowalevsky, Observations on the Development of the Brachiopoda (in Russian). Nachr. Ges. Mosc. xiv.
1873.

Shell small, ovate, longitudinally oval, longer than wide, about 9 lines in length by G
in breadth and 5i in depth. Valves uniformly convex and smooth, no fold or sinus ;
ventral valve somewhat deeper than the dorsal one ; beak moderately incurved, and
truncated by a small circular foramen slightly separated from the hinge-line by a narrow
deltidium in two pieces ; loops short and simj)le. Colour pale yellowish white.

Hah. Living in the Straits of Messina and off the Eolio Islands in the Mediterranean;
off Cape of St. Vincent (' Talisman ' Expedition), in 298-818 fathoms.

Ohs. Considerable uncertainty has prevailed with respect to this small shell, which
Philippi, in 1836, described from fossil Pliocene specimens as a variety of Terebratula vitrea.
Suess and otlaers declare it to be a distinct species, while others look upon it as a young
stage of Liothyris vitrea. I have compared species of the fossil shell with species dredged
alive by Prof. Seguenza in the bay of Messina, and found them to be identical. I cannot,
however, get rid of the idea that Liothyris minor is more than a small race or variety
of Liothyris vitrea ; it occurs, associated with the last-named shell, in the same beds and
localities in Calabria and in Sicily.

To Kowalcvsky's memoir on the development of the Brachiopoda (1873) the reader is
referred for observations relative to the embryology of L. minor.

Liothyris vitrea, var. Davidsoni, A. Adams. (Plate I. figs. 14-16.)

Terebratula davidsoni, A. Adams, Proc. Zool. Soc. London, p. 314, 1867.
Terebratula minor, Davidson, Proc. Zool. Soc. London, p. 302, pi. xxx. fig. 10, 1871.

Shell ovate, broadest anteriorly, tapering posteriorly, longer than wide, marginally
rounded. Valves uniformly convex, no fold or sinus, surface smooth, with faintly marked
concentric lines of growth ; beak incurved, truncated by a small circular foramen
margined laterally by two small deltidial plates ; surface of shell finely punctured.

second series. — zoology, vol. IV. 2

10 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Colour light yellowisli white ; loop small and simple. Length 10, width 7, depth
6 lines.

Hah. Dredged by A. Adams at Satanomosaki, Japan, in 55 fathoms.

Ohs. I am not quite certain that this small species is really a variety of L. vitrea. I
have seen only two examples of the shell, and they much resemble the typical var.
minor. One of the specimens bore some resemblance to young examples of Liothyris uva
from the Gulf of Tehuantepec, but diifers from it, according to A. Adams, in its more
solid structure and globose form, and in the foramen being smaller and entire. More
Japanese examples will have to be examined before tlie variety can be definitely
accepted.

2. Liothyris arctica, Eriele, sp. (Plate I. figs. 17, 18.)

. Terebratula arctica, Friele, Sserskilt Aftryk af Nyt Magazin for Natm'videnskaberne, pi. i. fig. i.^
1877.

Shell small, globose, broadly ovate, rather longer than wide. Valves smooth, glassy,
semitransparent, Avhitish ; dorsal valve convex, squarely circular, without fold or sinus ;
ventral valve very convex and deep ; beak unusually short, slightly incurved and
truncated by a very small foramen margined anteriorly by rudimentary deltidial plates;
loop very small and simple. Length 7, breadth 6, depth 4 lines.

Hab. Dredged by Herman Priele some few miles south-west of Jan Mayen, in 263
fathoms depth. Shell abundant, but so brittle that most of the specimens were broken
during the dredging-operation.

Ohs. After having carefully compared a specimen of the shell under description, sent
to me by Friele, with others of the var. minor to which it had been referred by
Dr. Jeffreys, I could, as Friele had previously done, discover several differences which,
although not very great, have induced me to follow its discoverer in considering it a
distinct species. L. arctica is much more globose and squarely rounded than L. minor,
which is more of an elongated oval. As stated by Eriele, its form approaches most to
L. minor of Philippi, but the deviation is shown in the shorter beak and by the position
of the foramen, which, in i. arctica, is placed directly above the dorsal valve, the
deltidium bekig almost hidden. The loop in i. arctica is very much weaker and
thinner, and the cru.ra processes are placed further apart than in Jj. minor. It is the
first representative of the genus Liothyris that has been hitherto found in Arctic seas.

3. Liothyris tjva, Broderip, sp. (Plate II. figs. 5-7.)

Terebratula uva, Broderip, Traus. Zool. Soc. Lond. vol. i. p. 14.2, pi. .xxii. fig. 2, 1833; Sowerby, Thes.
Concli. vol. i. p. 353, pi. Ixx. figs. 53-55, 1846; Reeve, Monogr. of the genus Terebratula, Couch. Icon,
pi. iii. fig. ii., 1860 ; Dall, Cat. of the recent species of the Class Brachiopoda, Proc. Acad, of Nat.
Sciences of Philadelphia, 1873; Davidson, Report on the Brachiopoda, Voyage of H. M.S. 'Challenger,'
Zool. vol. i. p. 31, pi. ii. figs. 3 & 4, 1880.

Shell oblong-oval, posteriorly compressed on each side, longer than wide, slightly
diaphanous, white or of a very light salmon-colour. Dorsal valve convex ; marginal

DE. T. DAVIDSON OX EECENT BEACIUOPODA. 11

liuc flexuously rounded in front ; ventral valve deeper than the dorsal one ; beak incurved,
moderately produced, obliquely truncated by a large circular foramen sejiarated from the
hinge-line by a narrow concave deltidium. Surface smooth, marked by fine concentric
lines of growth. Shell finely punctated. Loop short, simple. Length 1 inch 1 line,
width 8 lines, depth 6 lines.

Hal). Mr. Broderip states that this species was obtained at Tehuantepec by Capt.
Dare, while dredging for 3Icleagrince margaritiferce, attached to a dead sea-worn bivalve,
at a depth of 10-12 fathoms, and on a bottom of sandy mud. The type, formerly in
Mr. Cuming's collection, is now iu the British Museum. The shell was also trawled by
the ' Challenger ' Expedition off Twofold Bay, iu 120 fathoms, and dredged off Buenos
Ayres by the same expedition at a depth of GOO fathoms, and again off Heard Island,
lat. 52° 4' S., long. 71° 22' E., at a depth of 150 fathoms.

Obs. Ltolhyris uva varies much in shape ; it is usually longer than wide, and oval, but
in some examples the length and depth do not differ materially.

4. LiOTHYKis MosELEYi, Davidsou. Plate II. figs. 1-4.

Terebratula Moseleyi, Davidson, Proc. of the Royal Society, vol. xx^ii. p. 43G, 1878 ; Report ou the
Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 30, pi. ii. figs. 12-1 1, 1880.

Shell broadly ovate, semiglobose, rather longer than wide, broadest anteriorly, slightly
tapering posteriorly, marginally and laterally convex, nearly straight in front, margin
sometimes thickened, surface smooth, white. Dorsal valve uniformly convex, without
fold or sinus ; A^entral valve slightly deeper than the dorsal one, uniformly convex ; beak
moderately produced, slightly incurved and truncated by a circular foramen separated
from the hinge-line by a very narrow and small deltidium, beak-ridges not defined.
Loop in dorsal valve short and simple, labial appendages occupying about two thirds of
the length of the valve, united to each other by a membrane, the central coil making
about three turns. Shell-structure perforated by numerous small canals. Colour white.
Length 11, breadth 10, depth 7i lines.

Hab. Dredged by the ' Challenger ' Exjoedition, west of Kerguelen Island, at a depth
of 210 fathoms. Types in the British Museum.

Obs. I have reproduced the description I have given in the ' Challenger ' Report.
Five examples of this shell were obtained, all of about the same dimensions. It seems
to be a smaller and more circular species than L. citrea and L. sjj/ieuoidea. It is less
elongated, and not quite so convex as the last-named species, and does not present the
flatness and angularity observable in the mesial and lateral portions of the ventral valve
of Ij. sjjhenoidea or in its synonym I/, cubensis.

I made an examination of the animal of one of the specimens, which did not differ
materially from that of i. viti^ea. The mantle is thin, and not furnished with seta3 at
its edges. On the dorsal lobe of the mantle I distinctly observed the ramified, bifurcated,
flue, thread-like pallial nerves as well as the pallial sinuses, muscles, and brachial or
labial appendages, these last occupying a much smaller space in the interior of the
shell ; and while the labial branches are visibly shorter, the cirri are of considerable length.

12 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

5. LioTHYRis SPHENOIDEA, Philippi, sp. (Plate II. figs. 17-22.)

Terebratula sphenoidea, Philippi, Enum. Moll. Siciliie, vol. ii. p. 68, tab. xviii. fig. 6, 1844; G.
SegLieuza, Pal. Malac. dei Terreni Terziarii del distretto di Messina, Memorie della Soc. Italiana di
Scienze Naturali, p. 24, pi. ii. figs. 1-5, 1865 ; also Studii Paleontologici sui Bracbiopodi dell' Italia
Meridionale, pi. i. figs. 18-26, Pisa, 1871.

Terebratula cubensis, Pourtales, Contributions to the Fauna of the Gulf Stream at great depths. Bull.
Mus. Comp. Zocil. vol. i. pp. 109 & 124, 1867 ; Dall, lleport on the Brachiopoda obtained by the United
States Coast Survey Exp., Bull Mus. Comp. Zo51. vol. iii. pp.3-9, pi. i. fig. 2, 1871; Davidson, Report
on the Brachiopoda, Voy. H.M.S. 'Challenger,' p. 28, pi. ii. figs. 10-11, 1880; Dall, Bull. Mus.
Comp. Zool. vol. ix. p. 103, 1881.

Terebratula vitrea, var. sphenoidea, Jeffreys, Ou the Mollusca procured during the ' Lightning ' and
'Porcupine' Expeditions 1868-70, Proc. Zool. Soc. p. 404, pi. xxii. fig. 6, 1878.

Shell longitudinally more or less trigonal, broadest and rounded anteriorly, tapering
posteriorly, lateral marginal line flexuous, that of the dorsal valve forming an outward
curve, flexuously varying with age. Dorsal valve uniformly convex, sometimes I'ather
inflated ; ventral valve somewhat deeper than the dorsal one, longitudinally broadly
flattened, sides of the flattened portion sloping away rather abruptly ou either side,
giving the valve a somewhat subquadrangular aspect ; beak moderately incurved and
truncated by a circular foramen sej)arated from the hinge-line by a narrow deltidium.
Surface smooth, sometimes marked by fine radiating lines. Loop narrow, small, and
simple, bent-up band connecting the principal stems of the loop long and narrow.
Colour soiled white. Length 1 inch 3 lines, breadth 11 lines, depth 9 lines.

Mab. Recent. Atlantic (Jeffreys). West-African coast (' Travailleur ' and 'Talisman'
Expeditions). Gulf of Florida in depths of 100-200 fathoms, rarer towards east end
of reefs (Pourtales). Coast of Cuba (Sigsbee), off Havana 270 fathoms. Barbados
100 fathoms, St. Vincent 88 fathoms, Martinique 210 fathoms. Ofi" Ascension 420
fathoms (' Challenger ' Expedition). Off Morocco (' Talisman ' Expedition) in 298 to
818 fatlioms.

Fossil. In Pliocene rocks of Calabria and Sicily (Philippi and Seguenza).

Obs. In 1844, Philippi described and figured, as his Terebratula sphenoidea, some
fossil Pliocene specimens he had collected in the valley of Lamanto in Calabria. Subse-
quently Signor Seguenza found the same fossil in Philippi's locality, as well as in rocks
of the same age in Sicily. In 1878, Dr. Gwyn Jeffreys described and figured as Tere-
bratula vitrea, var. sphenoidea, a living specimen Avhich he had dredged during the ' Por-
cupine ' Expedition in 1870, from the Atlantic, at depths of 292, 374, and 994 fathoms, and
remarks : — "After a protracted and very careful examination of my specimens, which I had
considered the T. sphenoidea of Philippi, and having compared them with fossil specimens
sent me by Prof. Seguenza as Philippi's species from the Sicilian Tertiaries, as well as with
a series of T. cubensis which I received from Count Pourtales and Professor Alexander
Agassiz, and also after a close comparison of all these specimens with the description and
figures given by Philippi, Seguenza, Pourtales, and Dall, I am convinced the T. sphenoidea
and T. cubensis are the same, and constitute a well-marked variety of T. vitrea. The
loop in T. sphenoidea and T. cubensis is precisely similar." In this last remark, Dr. Gwyn

DE. T. DAVIDSOX OX EECENT BRACHIOPODA. 13

Jeifreys is cleai'ly mistaken ; for there exists a well-marked difference LetAveen the loops
of T. splienoidea and T. cubensls and that of L. vitrea. The loops in the fossil speci-
mens of Liotlijjris spheiwklea and those of the recent X. ciibcusis are exactly the same,
as had been clearly illustrated by Pliilijjpi in ISii.

As justly remarked by Prof. DaU, L. spheiioklea vai-ies much in shape according to
age and specimen: some are longer than wide, others almost as wide as long; some
taper more than otliers posteriorly, while much diflFerence is observable in the degree of
convexity of their valves.

In his description of T. cuhensis, Dall enters into minute details, in order to point out
the differences which exist between this last-named species and Liothyris vitrea. lie
has also carefully studied the animal of T. cuhensis, and points out the differences it
presents from that of JF'aldheimia Jloridana . He says, " the mantle is of stouter consistency
than in IF. Jloridana, and may often be removed from the shell with but little injury if
care be exercised. The muscles are similar in disposition to those of the other members
of the Terebratulida3, and present no new features. The peduncle is solid, cup-shaped
at its extremity, and has the edge produced in cylindrical horny rootlets, which are
attached to foreign bodies. The regular arrangement in layers of the muscles and corium,
as well as the axial tube of the peduncle, found in Linyula, is less evident or absent in
these forms. In this species the peduncle is very short and stout, broadly cordiform at
its inner extremity when enveloped by its various tunics.

" The brachia are arranged as in T. vitrea, as figured by Woodward ; the central coil
makes about four turns. The cirrhi are very short behind the mouth, in front of the supra-
a3S0iDhageal body. A striking feature in its anatomy, which I believe has not yet been
noted in any publication on Brachiopods, is the absence of that great series of sinuses in
the anterior part of mantle, which was termed by Hancock the ' great pallial sinuses.'
So extraordinary did this appear to me, that I could not believe, at first, that I was not
deceived by the translucency of the membranes, and it was only after an examination
of many specimens that I became convinced that they do not exist in this species. There
is in the free lobes of the mantle an extensive and extremely close and fine network of
minute channels ; or perhaps it might be said that the whole of the mantle-lobes form
one great lacune, the upper and lower walls of Avhich are held apart by a profuse number
of jjillars of tissue, which appear like dark spots under the microscope, and which are
situated so close together that the spaces about them are reduced to minute channels.
This system occupies the anterior lobes of the mantle, which in some species also contain
large branching sinuses, here absent. ... In the inner lining of the mantle are scattered,
everywhere, delicate, branching spicuhe, looking more like briers than like deer-horns,
and, while more or less interlocked, and here and there stout and thick, are still much
more delicate and slender than those of Terehratulina capiit-serpentis and Megerlia
truncata, and do not often exhibit a stellar arrangement. They are much more numerous
in some individuals than in others, and when present in abundance are found in almost
every part of the epithelium, even to the brachial cirrhi, w here the spicules are slender
and not branched .... The oesophagus is wide and fuunel-sha2)ed, narrowest at its
junction with the stomach, w'hich it enters at an acute angle. The stomach is

14 DK. T. DAVIDSON ON EECENT BRACHIOPODA.

small and oval, tapering towards the intestine, which is nearly twice as long as the
oesophagus.

" The heart in most specimens was pyriform and of a moderately large size.

" The genitalia . . . are situated in a reticulated series of sinuses, on the surfaces of
the sides of the perivisceral tissues.

" Ahove and behind the mouth, and directly in front of the anterior occlusor (retractor)
muscles, the external tissu.es of the perivisceral membrane are thickened, or a mass of
cellular tissue is interposed between the laminse of the membrane.

" No peculiarities of note were observed in the shell-structure. The perforations appeared
to be slightly further apart than in T. vitrea, but the difference was not much greater
than that which may be observed in the shells of different individuals of the same species."

Mr. Dall then describes what he believes to be the young of T. cuhensis, dredged off the
Samboes, on the Florida reefs, a minute, polished, liyaline shell, 4-lOOths of an inch in
length, and follows by describing the muscular system, brachia, and organs of digestion.

.Liothyris sphenoidea and its synonym T. cuhensis appear to be very abundant in
their especial haunts. I have also been able to examine the animal from one of the
specimens dredged by the ' Challenger ' Expedition. The mantle in the dorsal valve
of one of the specimens showed in a most distinct manner the four principal pallial
simises, which again branched as they approached the front margin of the shell,
and bifurcated again before reaching the margin.

6. Liothyris Bautletti, Dall, sp, (Plate I. figs. 20, 21.)

Terebratula bartletti, Dall, The American Naturalist, vol. xvi. p. 885, Nov. 1882.

Shell ovate, globose, longer than wide, broadest anteriorly, dorsal valve convex, with a
wide flattened mesial fold of very small elevation, commencing at about two thirds of the
length of the valve and extending to the front. Lateral and frontal margins sinuovis,
front line of fold nearly straight. Ventral valve slightly deeper and more convex than
the dorsal one, with a wide, shallow, flattened, mesial depression or sinus near the front ;
beak short, much incurved, overlying the umbo of the opposite valve, and truncated by a
small, oval-shaped, incomplete foramen. Surface smooth, marked with concentric lines
of growth. Colour light yellowish brown. In the interior of the dorsal valve the loop
is short and simple. Length li inch, breadth 1 inch 2 lines, depth 1 inch.

Hub. Dredged by the United States Coast Survey. Gulf Stream (' Blake ' Expedition)
near Vera Cruz, in 218 fathoms.

Ohs. I have seen one specimen only of this species, kindly lent to me by Mr. Dall. It
approaches much in general shape to some specimens of Liothyris vitrea. It differs
from Liothyris s]3henoidea {= cuhensis) in the shape of its loop, which is similar to that
of L. vitrea.

7. Liothyris subquadrata, Jeffreys, sp. (Plate II. figs. 15, 16.)

Terebratula subquadrata, Jeifreys, On the Mollusea procured during the ' Lightning ' and ' Porcu-
pine' Expeditious in 1868-70, Proc. Zool. Soc. London, 1878, p. 102, pi. xxii. fig. 3.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 15

Shell somewhat subjientagoual or pear-shaped, broadest anteriorly, tapering posteriorly,
longer than wide, rounded laterally, slightly indented iu front. Dorsal valve moderately
and evenly convex, somewhat flattened along the middle. Ventral valve deeper than the
dorsal one ; beak slightly incurved and moderately produced, obliquely truncated by a
rather large circular foramen, separated from the obtusely angular hinge-line by a well-
defined triangular area and long, narrow, dcltidial plates ; beak -margins sharply defined.
Surface of valves marked with numerous, wavy, fine, radiating riblets, widely separated
and crossed at intervals by concentric lines of growth. Colour ochreous white, csecal
tubuli minute and close-set. Loop small and simple. Length 1 inch 1 line, breadth
1 inch, depth 7 lines.

Mab. OQ the coast of Portugal, in 500-600 fathoms ; in the Bay of Biscay.

Ohs. The only complete specimen of this shell that I have seen is the one described,
which I figured for Dr. Jeffreys. It was given to me by Mr. Saville W. Kent, who had
dredged it during his cruise in Mr. Hall's yacht ' Noma ' off the Setubal coast, near the
Tagus in 1870. Since then I have been informed by Dr. Jeffreys that young examples
were obtained during the dredgings of the French shij) ' Travailleur ' in the Bay of
Biscay. It seems to be a good and well-marked species.

8. LiOTHYRis Wyvillii, Davidsou. (Plate II. figs. 8-14.)

Terebratula Wyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 436, 1878, and T. wyvilUi, Report on
the Brachiopoda, Voyage of H.M.S. 'Challenger/ Zoology, vol. i. p. 27, pi. ii. figs. 7, 8, 1880.

Shell somewhat subpentagonal, variable in shape, about as broad as long, sometimes
almost square, with rounded angles, with a concave sinus on the dorsal valve and corre-
sponding fold in the ventral one. Shell very thin and exceedingly brittle, almost
transparent, smooth, glassy, light-yellowish white. Length 7, breadth 9, depth 4|
lines. Valves in the young slightly and evenly convex ; dorsal valve moderately convex,
with a depression of greater or less depth commencing close to the umbo, and gradually
widening and deepening as it nears the front, front line wide, straight, or presenting an
inward curve. Ventral valve deeper and more convex than the opposite one, with a wide
median coiixex elevation or fold commencing near the beak, and one extending to the
front. Beak very small, slightly incurved, truncated by a small, generally incomplete,
circular foramen, laterally margined by dcltidial plates. Surface of valves marked at
intervals by concentric lines of growth ; shell-structure with minute, widely separated
perforations or canals. In the interior of the dorsal valve the loop is short and simple ;
the adductor and other muscular impressions are small and delicate. The labial appen-
dages extend to two thirds of the length of the shell. In the interior of the ventral valve
the muscular impressions are small, and occiipy a limited area close to the beak.

Sab. This remarkable and very interesting species appears to abound over a wide
geographical area, and at depths from 1035 to 2900 fathoms.

It was dredged by the ' Challenger ' Expedition at six or seven different stations. In
South Australia, in lat. 42° 42' S., long. 134° 10' E., depth 2G00 fothoms : one example
was attached to a manganese nodule. In lat. 12° 8' S., long. 145 10' E., depth 1400
fathoms ; bottom-temperatm-c 1^-3 C. In lat. 33° 31' S., long. 74° 43' W., depth 2160

IG DK. T. DAVIDSON OX EECENT BRACHIOPODA.

fathoms. Off coast of Chili (Valparaiso), along Avith Wald/ieimia TFi/villii -dnd Discimsca
atlantk-a. In lat. 42° 43' S., long. 82° 11' W., tlei^th 1450 fathoms. Off coast of
Patagonia. One small example from the net-weights, not far from Falkland Islands, at
a depth of 1035 fathoms. And, lastly, in lat. 35° 22' N., long 169° 58' E., depth 2900
fathoms, the greatest deptli at which any Brachiopod was ohtaiued by the ' Challenger '
Expedition ; bottom-temperature l°-2 C. ; sea-bottom, red clay.

Ohs. Liotlujris JFyvillii is one of the most interesting species of deep-sea Brachiopoda.
The shell is of such extreme thinness that it is almost transparent ; indeed the valves, when
separated, are really so, and the muscular impressions may be seen through its transparency.
I separated the valves of a specimen in order to be able to study the auimal and its loop.
The latter, which I was much surprised to find short, is exactly similar to that oiLiothyris
vitrea, notwithstanding the outward Waldheimia-Yv^e appearance of the shell. It bears
also much resemblance to several species of the last-named genus occurring in the Jurassic
and Cretaceous formations. We meet with but few recent species with such a thin
shell ; but among others may be named the widespread Discinisca atlaiitica, King,
Atretia gnomon, Jeffreys, JP'aldheimia or Macandrevia tenera, Jeffreys, RhijncUonella
lucida, Gould, and one or two others.

In external shape and character of loop, Liothyrts JFyvillii also strongly resembles
the Terebratnla nucleata of Schlotheim. Zittel's figure 644, on page 700 of his
' Handbuch der Paliiontologie,' 1880, seems as if drawn from a specimen of the recent
L. IJ'yvilUi. Eor T. nucleata Douville proposes a genus Glossothyris ; but this I am
unable to admit or adopt.

Fncertain Species.

9. LiOTHYRis CEUNiCA, Crosse, sp. (Plate I. fig. 19.)

Terebratnla cernica, Crosse, Journal de Conchyliologie, vol. xxi. p. 285, and vol.xxii. p. 75, pi. i. fig. 3,
1873.

Shell longitudinally oval, somewhat pear-shaped, longer than wide, broadest anteriorly,
tapering posteriorly. Valves uniformly convex and globose, lateral margins rounded and
flexuous. Surface smooth, white, semitransparent and somewhat vitreous. Beak not
much produced, incurved and truncated by a small circular foramen, separated from the
hinge-line by a deltidium in two pieces. Loop not known, in all probability short and
simple, as in L. vitrea. Length 1 inch 4 lines, breadth 1 inch 1 line.

Sab. Off Mauritius Island (Lienard).

Ohs. Mr. Crosse, in his description, says that T. cernica, from the lateral compression
of its dorsal valve, possesses affinities with T. ura, Broderip, but that it is less elongated
and more globose, and approaches T. vitrea and, even more closely, T. ciibensis of Pourtales.
I have never seen the single example of the shell under description ; but from inquiries
I made in the Island of Mauritius, Mr. V. Ptobillard has informed me that it has not
been dredged, but was found in the stomach of a fish taken at 80 fathoms depth, that it
is the only .specimen existing, and that there is but little chance of finding it again. lie
adds that he does not know of any other species of Brachiopod from the Avaters of

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 17

Mauritius, although lie has been studying' conchology there for the last forty-live
years.

10. LiOTHYRis ? vel Terebratulina Dalli, Davidson. (Plate II. fig. 23.)

Tvrebrutula ? Dall'i, Davidsou, Proc. Eoy. Soc. vol. xxvii. p. 437, 1878; and Report on tlie Brachiojioda.
Voyage of H.IM.S. ' Cliallengcr/ Zool. vol. i. p. 38, pi. ii. figs. 15, 15 a,h, 1880.

Shell small, thin, longitudinally oval, globose, glassy, semitransparent. Dorsal valve
moderately convex, slightly depressed anteriorly. Ventral valve uniformly convex, a
little deeper than the dorsal one. Beak small, slightly incurved, and truncated by an
incomplete foramen, laterally margined by small deltidial plates. Surface of valves
covered with fine, radiating, raised stria?, with shorter ones here and there, interpolaterl
between the longer ones. Loop short and simple. Length 3, width 2 lines.

Hab. One example only, without the animal, Avas dredged by the ' Challenger ' Expedi-
tion near Yeddo, olf Japan, lat. 34° 37' N., long. 140° 32' E., depth 1875 fathoms.

Obs. I am not quite certain whether this small shell is a Liothyris or a Terebratulina.
Its generic claims must be considered uncertain.

Subgenus Terebratulina, d'Orbigny, 1847.

The subgenus Terebratulina is closely allied to Liothyris. Wheu young, and up to
a certain stage of its development, the loop is similar to that of Liothyris ; but with age
the crural processes become united and form a shelly band, which is never the case in
Liothyris. Apart from the last-named peculiarity of the ring-shaped loop, the subgenus
Terebratulina well defines a small group of shells distinguished and characterized by
the presence of ear-shaped expansions on each side of the umbo, and by the fine
radiatinii: striae that cover the surface of their valves.

-'o

11. Terebratulina caput-serpentis, Linne, .sp. (Plate III. fig. 11^ ; Plate IV. tigs. 1-11;
Plate V. figs. 32-34.) [Figs. 35-37, var. enumjinata, Ilisso=var. mediterranea .
Jeffreys. See footnote, p. 25.]

Anomki capul-serpviitin, Liune, Syst. Nat. cd. duodecima reformata, vol. i. p. 1153, Holmia^, 1767.

Anomia pubescens, id. ibid. p. 1153.

Anomia retusa, id. ibid. p. 1151.

Animal Anomia; nondum antea depidum, Ad. Murray, Fundamenta Testaceologiae, Upsala, \). I.'},
pi. ii. fig. 23, 1771.

Anomia caput-serpentis, Pennant, (Linn^) Nova Acta Regiae Societatis Upsaliensis, vol. i. \). .'58, tab. v.
fig. 4, 1773.

Terehratula capiit-s-erpenfis (animal), Grundler, Naturforscher, Bd. i. p. 81, tab. iii. figs. 1-0, 1774;
Besehreibung mul Abbildung zweier natiirlichen Terebrateln, Naturf. Bd. ii. p. 80, 1774; Born, Musei
Csesarei Vindobonensis, ]>. 119, 1780.

Anomia capvt-serpentis, Chemnitz, Conchylieu-Cabinet, vol. viii. p. 103, tab. 78. fig. 712, 1785.

Terebrutula pubescens, Retzius, Nov. Gen. xv., 1788.

Terehratula caput-serpentis, Dillwyn, Cat. Recent Shells, 1817 ; Lamarck, An. sans Vert. p. 247, 1819.

Terebralula aurita, Fleming, Phil, of Zool. ii. p. 498, tab. iv. fig. 5, 1822, and History of British
Animals, vol. i. p. 3()9, 1828.

SECOND SERIES. — ZOOLOGY, VOL. IV. 3

18 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

Terebratula costata, Lowe, Zool. Journal, vol. ii. p. IOj, 1825.

Terebratula emarginala, Risso, Hist. Nat. de rEurope Meridionale, vol. iv. p. 388, pi. xii. fig. 175, 182G.

Terebratula quadrata, Risso, ibid. p. 389, pi. iv. fig. 176, 1826.

Delthyris spatula, Menke, Synopsis Methodica MoUuscorum, 2nd ed. p. 96, 1828-30.

Terebratula caput-serpentis, Philippi, Enum. Moll. Siciliie, vol. i. p. 84, tab. vi. fig. 5, 1836; Anton,
Verzeichniss der Concliylien, p. 23, 1836.

Terebratula Gervillei, S. V. Wood, Ann. & Mag. Nat. Hist. 1st ser. vol. vi. p. 253, 1840.

Terebratula Chemnitsii, Kiister, Martini & Chemnitz, Concliylien-Cabinet, vol. vii. p. 37, pi. 2i.
figs. 19 and 20, 1843.

Terebratula caput-serpentis, G. B. Sowerby,Thes. Conch, vol. i.p. 343, pi. ixviii. figs. 1-4, and pi. Ixxii.
fig. 116, 1846.

Terebratulina caput-serpentis, d'Orbigny, Ann. des Sci. Nat. vol. viii. p. 67, pi. vii. figs. 7 & 8, 1848.

Terebratulina cornea, d'Orbigny, 1848.

Terebratula caput-serpentis, Forbes and Hanley, Brit. Moll. pi. ivi. figs. 1-4, 1849.

Terebratulina caput-serpentis, Davidson, Sketch of a Classification of Recent Brachiopoda, Ann. &
Mag. Nat. Hist. 2nd ser. vol. ix. p. 365, 1852; Davidson, Br. Tert. Brach., Pal. Soc. vol. i. p. 12, pi. i.
figs. 3-6,1852.

Terebratula striata. Leach, Br. Moll. 1852.

Terebratulina striata, S. P. Woodward, Manual of the Mollusca, p. 215, 1854; Hancock, Phil.
Trans, vol. cxlviii., 1858.

Terebratula striata, L. Reeve, Conch. Icon. pi. iv. fig. 15, 1860.

Terebratulina striata, E. Deslongchamps, Recherches sur TOrganisation du Manteau chez les Brachio-
podes articules, 1864; Brusina, Moll. Dalmati, Verh. zool.-bot. Ges, Wien, Bd. xvi., 1866; Dall, Proc.
Acad. Nat. Sciences of Philadelphia, p. 179, 1873 ; Kowalevsky, On the Development of the Brach., 1874 ;
G. O. Sars, Bidrag til Kundskaben om Norges Arktiske Fauna, Mollusca Regionis Arcticae Norvcgiae,
tab. i. fig. 5, 1878 ; Jeffreys, Brit. Conch, vol. ii. p. 14, and vol. v. pi. xix. fig. 2, 1873-79 ; E. Deslong-
champs, Etudes critiques sur des Brachiopodes nouveaux ou peu connus, 1884*.

Shell ovate, somewhat pentagonal, longer than wide, broadest about the middle,
slightly rounded or indented anteriorly ; dorsal valve more or less uniformly convex,
but with sometimes a mesial longitudinal depression, marginally flexuous on the sides ;
lateral sides of the umbo auricular ; ventral valve convex, rather deeper than the dorsal
one, anteriorly mesially depressed ; beak rather short, gently incurved and obliquely
truncated by an incomplete foramen, posteriorly margined by the substance of the beak,
anteriorly by the extremity of the umbo, laterally by two small deltidial plates, no
distinct cardinal area or beak-ridges ; surface of shell densely covered with fine radiating
striae, few in number, coarse and simple when young, but rapidly increasing in
number with age, by means of bifurcation, and by the interpolation of smaller and
shorter ribs; both valves are also crossed by numerous concentric raised lines of
groAvth, more prominent in the young, finer and closer as the shell increases in size.
Loop short and simple in the young, with age becoming annular through the union
of the oral processes. Colour whitish, with a tinge of yellow, sometimes rust-stained.
Dimensions variable ; a large example measured 1 inch 3 lines, breadth 1 inch, depth
\ inch.

* In addition to the above references, the species has been aUudcd to by many other eonchologists and palieonto-
logists, such as by Gualtieri, in his Index Conch, tab. 96. fig. 3, 1742 ; by Davila, Cat. i. pL xx. ; Favanno, Conch,
pi. 41. fig. A", 1780, and by many others.

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 19

Hab. Spitzbci'gen and Davis Straits ; uortli-east European seas ; Oban and off Cumbrae
Islands, Loch Torridon, Scotland; off Belfast; Finisterre and Croix de Gavic; Morl)i-
han ; Cape Breton ; Adventure Bank ; off Guetaria, Spain ; north-east coast of Jamaica ;
Corea and Sagami Bay, Japan, &c.

Fossil. In the Upper Tertiaries of Sicily ; Coralline Crag of England, Belgium, sontli
of Spain, Azores, &c., &c.

Obs. No species of Bracbiopoda has been more thoroughly or more carefully studied
than the Anomki caput-serpentis of Linne. It is a very common and well-knoun
species, abounding in the localities where it is found, and has since 1767 attracted the
attention of a large number of malacologists.

The shell varies somewhat in shape and especially, according to age, in the number
of its ribs. These modifications have been often described by myself and others, and
most recently, in 1881, by M. E. Deslongchamps *. In tlie youngest condition the
shell tapers posteriorly, and is widest anteriorly ; the hinge-line is then almost strain-bt.
the auricular expansions comparatively larger, the foramen triangular or elongated oval.
In a specimen, less than a line in length, forwarded for my examination by the Marquis
de Eolin, the posterior half of the valves was smooth, while on the anterior half some
seven, scarcely developed, rounded radiating ribs were present. At one and a half line
the surface of each valve was ornamented with about ten simple rounded ribs Avith
interspaces of about equal breadth, concentrically crossed by equidistant projectiui;-
ridges, most prominent on the surface of the ribs. As the shell grows lar"-er, tlie
auricular expansions become smaller, the hinge-line obliquely or obtusely angular, the
ribs more numerous and finer, the lines of growth less prominent, and the greatest
breadth at about half the shell's length. Similar important modifications take place also
in the interior of the valves. In the interior of the dorsal valve, when quite vouui;',
and up to a certain age, the crura are widely separated ; but as the shell grows, the
pointed extremities facing each other extend nearer and nearer towards each other until
they become united and form a well-defined band, giving the loop an annelliform sha])e
and character.

The intimate shell-structiu'e of T. caput-serpentis has been described and fi'i-ured l)v
Dr. W. B. Carpenter, Oscar Schmidt, Prof. W. King, E. Deslongchamps, and others.
Dr. Carpenter says that it is in T. cajyut-serpentis "that tlie canals are of smallest
dimensions, their largest diameter being about jinjo of an inch, whilst their averao-e
distance from each other is about the same as in the preceding case \_JFaldheimia
Jlatescens, -j^ inch] — their regular arrangement, however, being so modified, that the

external orifices are principally seen upon the elevated parts of the plications,

whilst they open internally in similar rows."

When alluding to the shell-structure of T. caput-serpentis, in his valuable memoir on
the histology of the test of the Palliobranchiata (Trans. Roy. Irish Acad. vol. xxiv.
p. 148, 1869), Prof. W. King says : — " The species just mentioned, which is longitudinally
ribbed, has two kinds of perforations : those lying in the furrows are simple ; while those

* ' Etudes, critiques sur des Brachiopodcs nouveaux ou peu connus :' Caen, 1884.

3*

20 DE. T. DAVIDSON ON BECEXT BEACHIOPODA.

Iielonging to the ribs are antler-shaped, that is, twice, thrice, or oftener subdivided.
Occasionally the perforations are confined to the ribs, which causes
them to lie in bauds. It is only by the most eai'eful examination,
while grinding down the ribs to the level of tlie intermediate furrows,
tliat the true forms of the perforations can be determined. As the
modification in question is a very important one in many respects,
I have given two representations of it taken from a section prepared
l)y Dr. Rowney. Pig. 10 shows a band of antler-shaped joerforations
in the simplest state, magnified 60 diameters : it would have been
difficult to have represented them under the complex form they some-
times assume. Eig. 11 shows a portion of one of the perforations, magnified 210 diameters,
having each termination of its branches furnished with a brush-like bundle, which in
tliis species, as in Terehratula vitrea, is smaller than usual." [See woodcut, fig. 1 A & B.]

The shell-structure of T. ca2)ut-serpentis being so very remarkable, I asked my friend
Mr. John Young, of the Hunterian Museum, Glasgow, to carefully examine the shell-
structure of this species. He writes me on the 20th of April, 1885 : — " The shell-structure
of this species is of great beauty. The numerous canals incline from the lower margin
of the shell upwards towards the beak, but on the ribs of the shell they radiate from
llie centre of each rib to either side, there being a central row of tubes or canals that
])oint neai'ly straight upwards, while the other rows diverge. It is this bending inwards
of the tubes on each side of the ribs towards the interior of the shell that caused Dr.
Carpenter, in the introduction to your monograph, to state that they open internally in
rows. Dr. Carpenter is, however, wrong when he states that the pores or canals are
principally seen on the elevated parts of the plications (in this sjiecies), my etched speci-
mens show that they ojien quite as numerously in the hollows between the ribs. It is
only internally that the perforations gather together into rows with bare spaces between.
On the exterior surface of the valves the pores are more evenly distributed, owing to
the divergence of the tubes on the ribs. The perforations are not so well seen on this
species, previous to etching. The tubes on their passage through the shell-surface often
have a wave outward and upwards."

The embryology of Terehratulina caput-serpentis and of T. septentrionalis has been ad-
mirably investigated by Prof. E. Morse * and Prof. Kowalevsky t- Prof. E. Morse says : —
" In the first stage the embryo becomes widened at one end. The segments are barely indi-
cated, tlie posterior end is the widest, the anterior portion is ornamented with a conspicuous
tuft of long cilia, so peculiar to the embryos of many worms. The embryo is also clothed
with vibratile cilia, and in this condition slowly moves along the bottom of the dish
\vithout rising from it, or remains quiet. In the second well-marked stage the embryo
is divided into two prominent segments ; these expand and contract upon each other
slightly, and the cephalic segment has the power of partially bending from side to side.
In tills stage tlie embryo is most active, swimming rapidly in every direction and turning

* "Embryology of TirchratiiUna," Mem. Boston Soc. Nat. Hist. vol. ii. pp. 251-264, 1873; and "The
SyBtematic Position of the Lrachiopoda," Proc. Boston >Soe. Ivat. Hist. vol. xv. pp. 315-372, 1873.
t ' Untersuchungeu iibcr die Embryologie der Brachiopodeu :" Moskau, 1874.

1)1^ T. DAVIDSON ON llECEXT BEACHIOPODA. 21

al)iuplly about. The oesophagus also becomes dimly delined. lu the third stage the
peduncular segment is developed and projects from the posterior portion of what can
now be called the thoracic segment. At this stage the embryo either remains immovable
upon tlie bottom of the dish or slowly moves about. In two cases delicately barbed
setae to the number of thirty-five projected directly backward from the peduncular
segment. The embryo is still clothed with cilia, though the long pencil of cilia has
disappeared. The head is closely drawn to the thoracic segment, whicli becomes Avider
in transverse diameter, so as nearly to hide -the peduncle. In the fifth stage the thoracic
ring commences to fold, or turn iipward upon opposite svirfaces of its circumference, so
as to gradvially enclose the head ; one fold being made slightly in advance of the other
represents the larger or ventral valve. In this stage appear clusters of barbed and
deciduous setge upon tlie anterior margin, and in a later portion of this stage the first
hardened areas of the dorsal and ventral plates make their appearance, and the cirri
appear as bkinted papillae about the mouth. In the sixth stage the shell becomes
rounded, the peculiar scaled structure makes its appearance, and the formation of tubules
perforating the shell and of permanent setse takes place." Tlie author adds, further on,
" that the eggs not only fill the large pallial sinuses, but liang in clusters from the
genital band ; from these parts they escape by dehiscence, and float freely in the

perivisceral cavity The eggs ai'e not uniform either in shape or size." Prof.

Morse then describes in detail each of the stages ; but space will not allow me to
proceed further with his elaborate investigations, as they would demand numerous
illustrations. (See Plate V. figs. 1-31.)

Dr. Gwyn Jeffreys states, in vol. ii. p. 7 of his ' British Conchology,' that in the fry-stage
the little creature can creep and swim ; but, " After quitting the embryonic state, they
become invariably and permanently fixed to other substances, being incapable of any
other motion than making a half turn round the peduncle or pivot."

Mr. Lucas Barrett, who had an opportunity of examining T. caimt-serpentis in life,
says*: — "This species shows more of itself than any other, and protrudes its cirri
further ; it was met with everywhere [near the coast of Norway], in small numbers,
iu 30 to 150 fathoms, often attached to Oculina. The cirri on the re- j,j„ g

fiected part of the arms are shorter than those on the first part, as shown /^

in the woodcut. The cirri were almost constantly in motion, and / \

often observed to convey small particles to the channel at their base, '!;

When placed in a small glass of sea-water, the valves gradually opened.
Individuals remaining attached to other objects manifested a re-
markable power and disposition to move on their pedicles. Detached y. ccnrnf-.ta-jjcitix,
specimens could be moved about without causing the animal to "^"1- L. Barrett,
close its valves. If any of the protruded cirri were touched, the cirri were retracted
and the valves closed A\itli a snap, but soon after opened again. When the oral
arms are retracted the cirri are bent up, but are gradually uncoiled and straightened
when the shell is opened, before which the animal has often been observed to prntrude

* Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi. p. 2.57, 1855.

22 DE. T. DAVIDSON OX EECENT BRACHIOPODA.

a few of its cirri and move them about, as if to ascertain if any danger threatened.
Only on one occasion a current was observed to set in on one side between the two rows
of cirri. I had been attempting to ascertain the existence of currents, by introducing
small quantities of indigo into the water surrounding the animal with a camel's-hair
brush ; three times the water was forcibly drawn in, and tlie particles of indigo were
seen to glide along the groove at the base of the cirri in the direction of the mouth."
See likewise a paper by Herouard " Sur les courants de nutrition des Bracliiopodes,"
Journ. de Conchyl. vol. xxv. p. 229, 1877.

Hancock * says : — " The pallial lobes extend forward, but do not project beyond
the side of the body, w^here they become united, the junction being marked by a groove,
bordered by a ridge on each side. They are very delicate and transparent, so that the
great pallial sinuses can be distinctly traced, even to their terminal ramifications "
(p. 793). "The arms of W. [TFaldhelmia'] cranium and T. caput-serpentis are
disposed in the same manner as in W. cmstnilis; and in the former the calcareous
loop is precisely similar to that of the latter ; but in T. caput-se)'pentis it is very much
reduced, the extended lateral portions having almost entirely disappeared, little more
than the transverse portion existing; and this, together with the crural processes, which
are united below across the median line, forms a collar upon which the bases of the
arms rest. In this species, therefore, the expanded lateral portions of the arms are
without any apophysary support, and accordingly other means are provided for sustaining
them. The two produced lobules of the dorsal pallial lobe reach to the ends of these
portions of the arms as in TP^. australls ; and are stiffened with numerous, imbedded,
calcareous spicula, to such an extent, that when the soft tissues are removed by mace-
ration the form of the parts remains unaltered. The spicula extend also over the
surface of the inner lamina of the pallial lobe, and pervade likewise the walls of the
canal, and even the cirri ; so that the brachial apparatus becomes firmly fixed, and in
this way a substitute is found for the usual apophysary support." (Loc. cit. p. 808.)

It is, however, to Oscar Schmidt, so far as I am aware, that we are indebted for the
first notice of these remarkable sj)icula f , and in the Annals & Mag. of Nat. Hist. 2nd
ser. vol. xvi. p. 439, pi. x., I gave a translation, with figures, of Schmidt's observations.
The author remarks " that the mantle, oral arms, and cirri in Terebratulina caput-
serpentis contain an innumerable number of calcareovis plates, generally flattened,

dilated and irregularly denticulated, situated in close vicinity to each other

It is easily conceived [he adds] that these calcareous masses stiffen the parts which
contain them, and seem particularly to serve this function in the hollow cirri, thus
preventing their sides from sinking doAvn."

We are also indebted to Prof. E. Deslougchamps for an admirable memoir ' Recherches
sur rOrganisation du Manteau chez les Brachiopodes articules ' (Caen, 1864), in which

* Phil. Trans, vol. cxlviii., 1S58.

t " Die ncusten UntersuchuDgen iiber die Braduopoden von Owen, Carpenter und Davidson, mit einigen
Zusiitzen," Zeitsch. f. gesammten Naturwissenschaften, p. 325, 18o4. In 1856, Dr. S. P. Woodward exhibited,
at a meeting of the Zoological Society, the spicnla in the pallial lobe of T. ccqjut-serjMiitis (Proc. Zool. Soc.
p. 368, 1856).

DE. T. DAVIDSON OX EF.CEXT BRACHIOPODA. 2:5

lie minutely describes and illustrates the arrangement of the spicula in Terebratullna caput-
serpentis as well as in other genera in which they occur (sec Pi. IV. figs. 10, 11). lie
tells us that each of the lobes of the mantle in this species has four vascular sinuses, of
which the lateral ones are more developed than the median two, which last contain
in their interior the organs of reproduction. The spicula cover these sinuses, and
afterwards line the walls of the visceral cavity, producing two large convex surfaces,
which become united and thus completely close this cavity. In the dorsal valve the
mantle reflects itself on the brachial apparatus, formed here of calcareous laminae bent
in the shape of a ring, and spread themselves on the labial appendages, of which they
line the interior of the great canal, as well as the cirri ; the cirri, he adds, which I
have also carefully examined in many specimens, are stated by Hancock to be large,
much-branched, colovu-less, glass-like, and pellucid, somewhat like the antlers of a deer,
only the branches are all on the same plane and are flattened and depressed a little ;
that they are, however, frequently much complicated, forming a central network with
irregular radiating branches ; in others, again, the branches pass from a single network
centre. The spicula lie in the outer layer of the inner lamina, and are crowded to such
a degree that the edges of the branches are almost in contact, thus forming an extensive
though incomplete network of calcareous matter over the trunks of the great jiallial
sinuses ; elsewhere they are sparingly distributed towards the margin of the lobes, where
they are rather numerous. The brachial disk is trilobed, the central lobe elongated and
spirally convoluted.

In 1771, in the ' Fundamenta Testaceologiae ' it is represented as the animal of Terehru-
tulina caput-serpentis without its shell. In 1773, Pennant describes the same species, and
gives a figure of its labial appendages. Grundler, again, in 1774, devotes a whole
plate to enlarged figures of the same appendages, and in two of them points out the
position of the loop. Since that period they have also been described and illustrated
by several malacologists, and more particularly by Albany Hancock, in his classical
memoir ' On the Organization of the Brachiopoda' (1858). Mr. Hancock informs us,
at p. 793 of his work, that, " To facilitate the examination of the soft parts, it is neces-
sary to reduce the valves by dissolving them in dilute acid. When the calcareous matter
has entirely disappeared, and the calcified shell-membrane has been removed, the trans-
parent tegumentary envelope of the animal is exposed to view ; and this, when placed

in water, assumes the form of the shell Towards the posterior or umbonal

region the enlarged extremities of the shell-muscles are always apparent, clustered
together on each side of the antero-posterior line, forming reddish-coloured patches."

The muscles naturally divide themselves into two groups, the valvular and those for ad-
justing the shell to the peduncle. As the arrangement of the muscles is stated by Hancock
to be essentially the same in all the articulated Brachiopoda, and they have been described
further on in JFakUieimkt flavescens, it will not be necessary here to refer further to those
details, although it may be added that Hancock mentions an important modification as
occurring in T. caput-serpentis, which consists in the large and powerful dorsal adjustor
muscles not being attached to the hinge-plate, as in W. Jlavescens, but having their
insertions in the valve itself. The posterior extremities of these muscles are seen on the

24 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

surface of the auimal, on each side of the median line, elongated in the antero-posterior
direction, and extending between the occlusors, almost as far forward as their anterior
margins. They are of irregular form, and enlarged posteriorly in T. caput-serpentis.

In PI. IV. figs. 8 & 9, we give Hancock's two enlarged figures showing the dorsal
and ventral views of TerebratuVma caput-serpentis deprived of the shell, and exhibiting
the respective positions of the various muscles above described.

While alluding to the digestive organs, Hancock states {I. c. p. 814) that " In
T. cajmt-serpentis there appears to be only two hepatic ducts, and both in it and in
TF. [Waldheimia] cranium the intestine is very short, terminating in a blind sac
before it reaches the ventral wall of the perivisceral chamber. It tapers gradually to
a point which is rounded, and suspended in its place by the mesentery." The genitalia
exhibit a somewhat different arrangement in T. caput-serpentis to what prevails in
W. Jiavescens ; " they are placed in large sinuses situated in the pallial lobes, one
at each side. These sinuses are, however, nothing more than the enlarged trunks of
the so-called pallial vessels or great pallial sinuses. They are four in number, two in
each lobe, and the genital band, which is placed within them, forms a thick convolute
layer, with small spaces between the folds."

" In T. caput-se7'pentis the heart is more decidedly pyriform than in the other species,
and it is placed a little further back, the branchio-systemic vein passing for some distance
down the stomach beyond the central gastro-parietal band . . . The setse in T.capiU-serpeatis
are placed rather far apart from each other, and issue from the mantle at the points
corresponding to the marginal crenulations of the shell ; these crenulations give to the
pallial membrane a scalloped appearance. The setae are rather robust ; the marginal fold
is deep, and the follicules are of considerable length and rather wide, with their bases
su.rrounded with glandular matter, forming a roundish, red-coloured spot at the end of
each seta " {I. c. p. 829). The blood-system of the brachial ajiparatus has likewise been
well investigated by Hancock. He says : — " This is beautifully developed, and presents
considerable variety in the character of the several plexuses of which it is composed. The
walls of the great canal, the ridge supporting the cirri, the membranes that unite the
upper and lower members of the loop, that which connects the spirals, and those which
form the small canal or channel at the base of the cirri, as well as that forming the
sheath of the apophysary support, — all have their system of lacunes which inter-
communicate and compose the brachial system " [1. c. p. 831).

Dr. Van Bemmelen questions the lacunary system as described by Hancock. He
concurs in the statement that in T. caput-serpentis and T. septentrionalis the sexes are
separate *.

While treating of the perivisceral chamber, Hancock observes that in T. caput-serpentis
the four trunks may be recognized. " Here the trunks are fused so as to form on each
lobe two large, lateral, semilunar sinuses, in which the genitalia are placed. The external
margins of these sinuses give ofi" numerous, rather delicate branches, which dividing
dichotomously run to the pallial margin ; the branches next the middle line, which

* •• Oil the Structure of the (Shells of liruchiopuds and Chitons," Ann. & Mag. Nat. Hist. 5th ser. vol. xi. p. 37y.

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 25

correspond to the inner sinuses, pass off from their internal margins, and divide once
or twice " (/. c. p. 840).

Terebratulina caput-serpentis, var. unguiculata. (Plate V. figs. 38-40.)

Terebratula unguicula, V. Carpenter, Proc. Zool. Soc. 1865, p. 201, figs. 1-4; Cooper, Gcogr. Cat.
California. Moll. p. 3, 1866 ; Dall, Amer. Journ. of Conch, vol. vi. p. 102, 1870, and Report on Brachiop.
of Alaska, 1877; S. T. Whitcaves, On Some Marine luvertebrata from the West Coast of North
America, Canadian Naturalist, n.s. vol. viii. p. 464, 1878.

Shell ovate, longer than wide ; valves almo.st equally convex, rounded laterally and
in front ; lateral sides of the umho strongly auricular, especially in young and middle-
aged specimens. Ventral valve evenly convex, but sometimes very slightly depressed
anteriorly ; beak short, obliquely truncated by a rather large incomplete foramen, margined
anteriorly by the umbo of the dorsal valve and by two small lateral deltidia. Surface
of valves marked with numerous radiating delicate riblets, simple aud stronger at their
origin, but rapidly augmenting in number from bifurcation and by the interpolation
of shorter riblets between the longer ones. Valves crossed with concentric raised striaj.
Loop short and simple, the crura disunited in the young, annelliform in the more advanced
age. Colour light yellowish white. Length 13, breadth 10, depth 5 lines.

Hab. San Diego, Cal., to the Aleutian Islands, San Pedro, Cal. (Cooper) ; Neeah Bay
(W. T. Swan) ; Victoria (V. W. Lord, J. Richardson) ; Port Etches ; Sliumargin Islands ;
Unalaska (Dall). Eange : low Avater to 100 fathoms, those from deep water, the largest,
adhering to shells and stones (Dall). At Race Island lighthouse, and Victoria Harbour,
in 30 to 70 fathoms; end of Texada Island, in 40 to 70 fathoms, mud (Richardson).

Obs. Mr. Dall states, in the paper already referred to, that this species is readily
separated from Terebratulina caput-serpentis, T. japonica, and other species, which
strongly resemble it externally, by the broad loop, which is usually open, instead of being
closed, as the genus requires. However, it finally becomes closed in fully adu.lt specimens,
which reach the size of T. caput-serpentis. I have also had the advantage of being able
to examine a large number of young and adult examples of Carpenter's species, which
were kindly lent to me by Mr. Whiteaves, as well as others which I purchased from
Mr. G. B. Sowerbv, who had obtained them direct from Vancouver Island. After havinsr
minutely compared their exterior and interior with a large number of European speci-
mens of T. caput-serpentis, I arrived at the conclusion that T. unguicula is no more
than a variety of Linne's species. Carpenter's specimens, as he himself admits, were all
of small size, and consequently the crura of the loop were disunited. The specimens of
T. unguicula I was able to open had not the broad loop described by Dall, but agreed
well with the European specimens of T. caput-serpentis which I had previously opened
and examined. In these specimens of T. unguicula, the front line was rounded, and
not indented; but this is also the case with very many examples of T. caput-serpentis.

In a letter dated December 1884, Mr. Dall writes me that he would not wish to be
quoted as believing T. unguicula distinct from T. caput-serpentis *, aud would be only

* [Dr. Davidson has given three excellent figures (sec PL V. figs. 35, 30, <fe 37) of the well-marked variety of
Terehratulina caput-serpentis from the Mediterranean Sea, to which Dr. Gwj-n Jeffreys gave the varietal designation
of mcditcrranea. He described it as longer aud more slender than T. caput-serpentis, " more compressed or flatter than

SECOND SERIES. — ZOOLOGY, VOL. IV. 4

26 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

willing to assert that the specimens he has seen seem distinguishable, and that as the dis-
tribution of the two forms is absolutely separate, their identity would seem to require proof.

12. Terebratulina. Cailleti, Crosse. (Plate V. figs. 41, 42.)

TerebratuUna Cailleti, Crosse, Journ. de Conch, vol. xiii. p. 27, pi. 1. figs. 1-3, 1865 ; Pourtales, Bull. ^lus.
Comp. Zool. (Harv.) vol. i. p. 109, 1867 ; Dall, Am. Journ. Couch, vi. p. 106, 1870, and Bull. Mus. Comp.
Zool. (Harv.) vol. iii., 1871 ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. Challenger,'
Zool. vol. i. p. 37, pi. 2. fig. 2, 1880; Dall, Bull. Mus. Comp. Zool. (Harv.) vol. ix. p. 103, 1881.

Shell ovate, longer than wide, broadest about the middle, rounded or slightly indented
in front ; dorsal valve evenly convex, no defined mesial fold, lateral sides of the umbo
auricular ; ventral valve moderately convex, with a strongly marked longitudinal depres-
sion or sinus, commencing at the beak and extending to the front ; front raised into a
rounded wave ; beak short, and obliquely truncated by a moderate-sized incomplete
foramen and two small disunited deltidial plates ; surface of valves marked with about
forty small radiating riblets, the larger number being shorter ones interpolated at various
distances between the larger ones ; surface marked also with fine concentric raised lines.
Loop short, crura disunited in the young, annelliform in the adult. Colour of a slightly
greyish white. Length 5, breadth 4, depth 2 lines ; but Mr. Dall mentions having taken
specimens 1 inch in length.

Hab. T. Cailleti was obtained by M. de Pourtales off Chorrera, Cuba, in 270 fathoms ;
near Cojima in 450 fms. Off Double-headed Shot Key in 471 fms., and near Tennessee
Eeef in 115 fms. Ofi" West Florida 30 fms., St. Vincent 88 fms. (Pourtales and Dall).
At Guadaloupe in 200 fms., by an Italian party who were searching for beds of coral.
Mr. A. Agassiz sent me a specimen dredged by the Hunter Expedition off Barbados, taken
at a depth of 100 fms., and I have also two young examples dredged by L. Barrett off
Jamaica, and by Sigsbee off Havanna, in from 80 to 450 fms. I am likewise indebted to
Mr. E,. Bathbun for several young specimens obtained in 70 fms. in lat. 21° 48' S. and
long. 40° 3' W. of Greenwich, which had been dredged by the Captain of the English
Atlantic steamer ' Norseman.' A single example was obtained by the ' Challenger '
Expedition, west of Pernambuco, in 350 fathoms.

Obs. This species has been minutely described by Mr. H. Crosse and by Mr. W. Dall.
Crosse says that it is easily distinguishable from T. caput-serpentis by its stronger radi-
ating riblets, these last being more separated from each other than in Linne's species.
When quite young, and measuring 1 line in length, it has only from nine to ten simple
ribs ; at 2 lines abeady two or three short interpolated riblets have made their appearance
close to the margin ; at 3 lines in length the interpolated riblets become more numerous,
and the whole surface is concentrically crossed by strongly marked, slightly projecting,
equidistant, concentric ridges. Tiie ridges become very much less marked as the shell
aj)proaclies and attains the adult condition ; but this feature is common to several species
of the subgenus.

usual, and more or less cloven in front " (" Mollusca of the ' Lightning ' and ' Porcupine ' Expeditions," Proc. Zool.
Soc. 187S, p. 401). From a MS. note attached to the types in the Davidson Collection, it is evident that Dr. Davidson
considered this to be " a good variety of T. caput-serpentis," but identical with the sheU named Terebratula
I'maiyinata by Risso in 1826, " of which the Terehratula <piadrata, Risso, is probably a synonym." The variety
mediterraneci should therefore be henceforth known as T. caput-scrpentis, var. eniargiiuita, Risso. — A. C]

DE. T. DAVIDSON OX EECEXT BEACHIOPODA, 27

Ml". Uall, iu bis paper in the Bull. Mus. Coiup. Zool. already referred to, enters into
many details to show that it is a distinct species. He has since then written me that,
although T. Cailleti may be a southern form of T. cajnit-serpentis, be has seen
probably nineteen twentieths of all the existing specimens, and that it seems to him to
be as well disting-uisbable as any of the fossil forms, and that he considers it at any rate
fully entitled to a varietal name, as it is well distinguished by its granulated ribs, and
varies much in form.

Dall says {I. c. p. 10) " That the smallest specimens of tliis species which I was able
to find among those sent by M. de Pourtales were nearly -1 inch in length. That

the characteristic sculpture was developed upon them to the very apex of the shell

The various muscles were already well developed. The mouth was as described in the
young of the T. cubensis. The intestine was short, cylindrical, and straight. The loAver
portion was embraced by a few hepatic digitations. These lobes were very dark brown,
the muscles of a deep reddish brown, and the brachia of a flesh-colour. The latter were in
the shape of a horseshoe, with no trace of a median lobe. They were close set and marked
with transverse lines as in T. cubensis. The membrane which covered the viscera was
covered internally with irregular hyaline spots with well-marked bou^ndaries, which no
doubt are the limits of the lacunar channels of circulation. The mantle was quite trans-
parent, with a brownish edge, and in each of the internal channels, corresponding to the
ribs of the outside of the shell, was a single bristle, composed of longitudinal fibres of
chitine, without any of the transverse markings which are seen in the setae of the adult.
The extreme tip of the bristle alone protruded from the mantle, and its inner extremity
was slightly bulbous. It was of a glistening yellow color throughout. In those adults
which I examined there Avere only five or six of these setse iu each mantle lobe. These
specimens were obtained off Havana, in two hundred and seventy fathoms water. The
very extraordinary manner in which all the soft parts were crowded and crammed with
masses of calcareous spiculse defied my best efforts to obtain any very satisfactory results
from the two or three alcoholic specimens at my command. A flocculcnt mass of white
matter resisted the action of acid, and filled all the interstices of the membranes so as to

render them quite opaque The intestine was cylindrical, and ended much as it does

in T. cajnit-serjjends. The mouth was surrounded by a dark-brown line. There were no
structures above and behind the mouth, such as are described as existing in T. cubensis.
The attached extremities of the muscles were of a very bright red-brown. . . . The peduncle
is white, slender, and exceedingly long, the exposed portion sometimes equalling in length
one third of the shell. A brownish tinge pervaded all the tissues of the adult. Transverse
markings were noticed iu the brachia, as described in other species by Hancock. One
specimen, growing on a rock which had become covered with sponge, afforded an interesting
observation. The peduncle was exceedingly long, and on cleaning off the sponge it was
seen that the creature, on the growth of the sponge towards it, had apparently lengthened
its peduncle to get out of the way ; and while the original attachment still remained, . .
. . somewhat further on, nearer the shell, a second attachment of the peduncle had taken
place by the outgrowth, from the underside, of a biincli of cylindrical rootlets, exactly

resembling the attachment of an ivv to a stone.

4*

28 DK. T. DAVIDSON ON RECENT BEACHIOPODA.

13. Terebratulina sbptentrionalis, Couthouy. (Plate V. figs. 1-31 & 48-52.)

Terebratulina septentrionalis, Couthouy, Boston Journ. Nat. Hist. vol. ii. p. 6.5, pi. iii. fig. 18, 1838.

Terebratula septentrionalis, G. B. Sowerby, Thes. Conch, p. 342, pi. xviii. figs. 5 & G, 18-J.6; Stimpson,
Test. Moll. New England, p. 75, 1851.

Terebratula cujjut-serpentis, L. Reeve, Monogr. of Terebratula, Conch. Icon. 1861.

Terebratulina septentrionalis, E. Morse (On the early Stages of), Mem. Boston Soc. Nat. Hist. vol. ii.
(read Oct. 1869) ; Gould, Invert. Mass., Binney's 2nd ed. p. 208, fig. 500, 1870.

Terebratulina septentrionalis, Dall, Cat. of Recent Bracli., Proc. Acad. Nat. Sci. Philadelphia, 1873,
p. 180; Sars, Fauna Moll. Regiouis Arctics Norvegise, p. 10, tab. i. fig. 4, 1878.

Terebratulina caput-serpentis , var. septentrionalis, Davidson, Report on the Brachiopoda, Voyage of
H.M.S. 'Challenger,' Zoology, vol i. p. 33, pi. i. figs. 3-9, 1880.

Terebratulina caput-serpentis, W. F. Ganong, The In^'ertebrate Zool. of Passamaquoddy Bay, Nat.
Hist. Soc. of New Brunswick, Bull. No. 4, p. 91, 1884.

Shell rather thin, longitudinally broadly ovate, pear-shaped or somewhat subpen-
tagonal, narrow and tapering posteriorly, abruptly widening below the beak, broadest
anteriorly ; front line nearly straight, slightly indented or rounded ; colour yellowish
white, nearly diaphanous ; dorsal valve gently convex, especially towards the middle,
slightly depressed towards the front, eared at the umbo ; ventral valve feebly convex,
or slightly deeper than the dorsal one, somewhat depressed towards the front; beak
short, attenuated, slightly incurved and truncated by a moderately large and incomplete
semielliptical foramen, completed below by the umbo of the ventral valve, and laterally
margined by small deltidial plates; surface of both valves covered with a variable
number of fine rounded radiating raised striae or riblets (240 in some specimens when
counted at the margin), these increase in number at variable distances from the beaks
by the interpolation of shorter riblets; shell-structure perforated by numerous small
canals. In the interior of the dorsal valve the loop is short and simple, rendered
annular, with age, by the union of the oral processes. The brachial appendages are
united to each other by a membrane, cirrated and develoijed from each side of the mouth,
divided into three lobes, the two lateral ones extending to a little more than two thirds
of the length of the valve, the central one not exceeding half the length of the valve,
and spiral at its extremities. Proportions variable. Length 16, breadth 11, depth
6 lines.

Sab. The geographical range of T. sejjtentrionulis seems to be very extended. The
' Challenger ' Expedition dredged it abundantly olf the New- York coast at depths of
61 fathoms, also, at a depth of 83 fathoms, off Halifax. Again, accordmg to the ofiicers
of the expedition, ofi" the Cape of Good Hope (but I should like to have this last state-
ment confirmed), at latitude 46° 40' S., long. 37° 50' E., at a depth of 160 fathoms.
Mr. Couthouy, in his description of T. septentrionalis, says that it has been found at
Lubec Bay by Dr. C. T. Jackson during his geological survey of the State of Maine, and
that it is proljably an inhabitant of deep water on the whole New-England coast.
Dr. Gould mentions having found it in considerable numbers in the stomach of fishes,
and occasionally on the sea-beach, and that its usual habitat is in the Laminarian or
deep Coral zones of northern seas. At Eastport, at low water, it is common off the

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 29

Isle of Slioals, 20 fathoms ; Grand Manau, common (Packard, Stimpson) ; Halifax
harbom- (Willis); Trias Cove, Passamaquoddy Bay, in 12 fathoms, where they occm-
clinging; together in bunches, large and small together, and seem to prefer the clear
fresh water on pebbly bottoms (W. P. Ganong).

Ohs. The above description is the one I published in my ' Challenger ' Report. Some
difference of opinion has prevailed with respect to the specific claims of the species under
description. Certain malacologists consider it a distinct species, others as only a simple
variety of T. capuf-serpeiitis. Gould, in 1838, believed it to be distinct ; but in the ' Report
on the Invertebrates of Massachusetts ' (2nd ed. by W. H. Binney, 1870) we find stated
at p. 208 : — " An examination of the descriptions of T. caput-serpentis given by Linnaeus,
Miiller, and Chemnitz, and a comparison of them with our shell, has well satisfied me of
their correspondence. The downy epidermis is a character too rare and singular to be over-
looked. This, however, is rubbed ofi" very easily. The shell is much thinner, in general
more elongated, and the strise nearly twice as nvimerovis, being about thirty to forty in
the Eui'opean, and fifty to sixty in the American specimens. No account of the internal
bony processes is given in any description except that of Mr. Couthouy. These would
afford the best possible specific character, were it not that they are usually more or less
broken. But I have been relieved from all further speculation by the receipt of specimens
from Dr. Loven, which settle the identity of om- species with the European caput-serpentis.'"
Mr. TV. H. Binney seems to be of a difi'erent opinion, for he adds, after Gould's observa-
tions just recorded : — " I have retained the above remarks from the former edition, because
our shell is so generally still regarded as identical with the European species. But further
examination of numerous specimens has led me to coincide with Dr. Stimpson, who has
dredged extensively, both in the British and American seas, in his opinion that the species
differs from the European caput-serpentis, sufficiently in both shell and animal."

G. B. Sowerby, on p. 344 of his ' Thesaurus Conchyliorum ' (1846), observes that
T. septentrionalis is distinguished from T. caput-serpentis by its much finer radiating
striae, its larger and less oblique foramen, and by its rather more extended and somewhat
difi'erently formed internal appendage.

Since publishing my description of this shell in the reports of the ' Challenger ' Expe-
dition, I feel more disposed to leave T. septentrionalis and T. caput-serpentis as separate
species, the first being evidently more regularly oval and rounded in front than in
Linne's species ; and even in the young stage the riblets are more numerous than in
T. caput-serpentis. I have been able to examine specimens from less than 1 line in
length up to that of 1 inch and 3 lines. Up to about 3 lines, and sometimes even more,
the ribs are very few in number, prominent and radiate from tlie extremity of the beak
to the margin, and are crossed by strongly indented concentric lines, which give to the
ril)lets the so-termed tuberculated appearance that has been so often described in the
species of this subgenus. As the shell grows the ribs become more delicate and more
numerous from repeated interpolations of shorter ribs, and tlie concentric ones become
more and more faintly marked.

It is, however, to Prof. E. Morse that science is most indebted for the knowledge we

30 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

at present possess of the embryology, or early stages, of Terehratulina septentrionalis *.
This distinguished zoologist having dredged in 15 fathoms of water in the harbour of
Eastport, Maine, in 1869, individuals of all ages, has minutely and elaborately described
all the stages of its development, which he illustrates in the most complete and admirable
manner. The details and illustrations he communicates are so numerous that we feel
ourselves obliged to refer the reader to the author's memoir, and to limit ourselves to
the reproduction of the following selected observations and illustrations ; he says : —
"The species occur in great numbers, at various depths, and have also been collected
at low-tide mark, by Dr. Stimpson and Prof. Verrill. The specimens were found
attached to stones brought up in the dredge, and also adhering to the lower valve of
adult individuals, generally near the peduncle f The eggs were generally kidney-
shaped, though very irregular as to form and size [see Plate V. figs. 1-4] ; they
were spermaceti-white in color, and opaque, though having a central area, translucent,

and apparently depressed This form recalled the general proportions of Argiope

and Megerlia, in being transversely oval, in having the hinge margin wide and straight,
and in the presence of a proportionately wide foramen. This stage was exceedingly
minute, .... the shell showed nothing of the scale-like structure so characteristic
in later stages. Between this stage and the next, tlie shell rapidly elongates, while
the hinge margin remains nearly the same in width ; this is also shown in the concentric
lines of growth seen faintly on the surface, indicating a rapid increase in the length of
the shell, while no corresponding increase takes place in the widening of the hinge
margin. The peduncle is longer than the shell, having distinct walls apparently enclosing
a clear interspace, the end slightly dilating and forming a pear-shaped adhering disk.

The structure of the shell showed clearly the scale-like structure, with the csecal tubules

of the pallial lobes perforating it. The anterior margin of tlie pallial lobes gave rise to
seven setse of variable lengths, all of them projecting forward [Plate V. fig. 21]. . . . The
future position of the calcareous loop was indicated by a strongly arched process midway
the length of the shell, from which sprang six short and stout cirri, all of them curving
towards the mouth, which occupied the centre of the base from which the cirri sprang.
The digestive sac hung from the mouth, and was twice as long as broad, having a strong
constriction in the centre, forming two chambers, the lowermost one being globular in
shape, and having its walls colored a light reddish-brown, this colored portion evidently
indicating hepatic cells. The cavity next the mouth indicates the stomach, whilst the
lowermost cavity indicates the future intestine or cul-de-sac. The cirri moved fre-
quently, and in various directions, though generally performing a grasping motion, as if

securing some bit of food In this stage, and several succeeding stages, the outline of

the shell is remarkably like that of Lingula, and this resemblance is more striking from
the proportionally long peduncle. [Plate V. fig. 31.]

" In another stage, the numerous irregular shaped calcareous spiculae lined the outer

* " On the Early Stages of. Tcrehratulhia septentrionalis," Memoirs of the Boston Society of Natural History,
vol. ii. p. 29, 1871 ; and " Embryology of Terehratulina''' ibid. p. 249.

t On an adult specimen of T. septentrionalis, dredged by the ' Challenger ' expedition, I counted no less than
twenty-eight young shells of the species attached to the surface of both valves, and more especially to its peduncle. — T. D.

DE. T. DAVIDSON OX RECENT BRACHIOPODA. 31

margin oi' the cirri, while the future position of the calcareous loop, or crura, was indi-
cated by a row of irregular-shaped spiculae. ... In these slightly advanced stages, the

peduncle becomes much shoi'ter in proportion to the length of the sliell In aU these

stages the peduncle has very slight adhesion to the rock or whatever substance it may be
attached to, in this respect differing greatly from the adult, which often requires at this

age great force to detach it I was fortunate in observing an individual [slightly

larger] in motion. The animal whirled quickly on its peduncle ; when at rest the sheUs
were always closed, and rested on the rock ; from this position it turned slowly more
than half way round, raising the body at the same time almost erect ; this movement
being completed, the valves would very slowly open, and the cirri expand as if to perform
a grasping motion ; in no case, however, were they projected beyond the margin of the
valves. The cilia lining the cirri produced gentle currents in the water. In this position,
with the valves widely open and the ckri expanded, the animal would remain motionless
for twenty or thirty seconds, and then, wdth an abrupt closing of the valves, suddenly

assume its first position In watching these motions for a long time, one could not

help being impressed with the fact that great caution was evidently indicated in the slow
and careful movements made in elevating and opening the shell, while the prompt closing
of the valves, and the alert manner in which the animal regained its first position, seemed
to show that food had been secured, and fm-ther caution was unnecessary."

Prof. Morse then goes on to describe how in successive stages a fold on each side of
the stomach was first noticed, these folds being the first appearance of the liver, then the
upper portion of the digestive sac and that portion which answers to the CBSophagus and
stomach in the contracted state, while the lower portion is widely expanded. In a still
more advanced stage, he says : — " The shell is now becoming proportionally broader and the
cirri increase in number, though still forming a simple circle around the mouth. The
crura have also begun to form. At a considerably more advanced stage " The cirri are
more numerous, numbering thirty-one : two of them are seen encroaching upon the
circular lophophore, and at this stage the lophophore has begun to assume its hippo-
crej)ian character.

" The crura are plainly seen supporting the crown of cirri, and the liver already shows
the first indications of its differentiations under the peculiar csecal ramifications which

become so numerous in the adult The divaricators are completely formed, and

between these two muscles is seen the lengthened intestine, the blind extremity of
which is held firmly to the shell by a membrane, called by Hancock the ventral
mesentery." At this stage " Radiating ribs, to the number of fifteen, ornament the
shell."

Successive stages are then described. At p. 35 of his admirable memoir. Prof. Morse
enters into Ions: details in connexion with the structure of the shell ; he savs : — " In the
youngest stages of the shell the scale-like structure may be studied to the best advantage.
The scales are few in number, but slightly overlapping, and form a layer quite distinct
from the outer layer, which appears to be homogeneous, save the concentric lines of
gi'owth appearing like rows of oblong and flattened nodules. The terminal portions of
the pallial caeca within or upon this outer layer, are brown in colour and distinctly

32 DE. T. DAVIDSON ON EECENT BKACHIOPODA.

arrauulated. . . . the tubules radiate from the larsjest diameter of the caeca, and not from
the periphery of the granulated disk, and this is in accordance with the admirable obser-
vations made by King *. The scales do not appear to encroach upon the walls of the
caeca."

Then follow many very important details on the growth of the shell, as well as the
gradual development of the crura and loop. The crura of the calcareous loop, although
not connected by a calcareous shelly layer in the young animal at all stages, have
portions nevertheless connected by a membrane charged with spicula. The peduncular
opening also, with age, becomes more circular, while the cardinal process, which does
not appear in the earlier stages, is latterly present.

In Prof. Morse's memoir in question a vast number of important details are
given, to which we have only briefly alluded.

I have myself examined specimens at all stages of growth, brought home by the
' Challenger ' Expedition, and I am able to confirm Prof. Morse's accurate observations.
When half a line in length the dorsal valve is elongate semicu-cular, the hinge-line
straight, and nearly as long as the breadth of the shell, only eight or nine rounded ribs
ornamenting the surface of each of its valves ; by degrees the hinge-line becomes shorter
and obtusely angular, and the ribs that ornament the surface of the valves become more
numerous.

14. Terbbratulina Wyvlllii, Davidson. (Plate III. figs. 1-3.)

TerebratulinaWyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 436, 1878, and [T.ivyvilii) Report on the
Bracliiopoda, Voyage of H.M.S. 'Challenger/ Zoology, vol. i. p. 32, pi. i. figs. 1-2, 1880.

SheU large, trigonal, longer than wide, broadest anteriorly, light yellowish; dorsal
valve triangular, anterior angles rounded ; hinge-line obtusely angular, moderately
convex, somewhat flattened along the middle, and abruptly bent inwards close to the
margin; lateral sides of the umbo auricular; ventral valve convex, deeper than the
opposite one, flattened anteriorly, abruptly bent inwards close to the margin ; beak
incurved, truncated by a large oval-shaped foramen, separated from the hinge-line by a
triangular concave depression sharply defined laterally ; surface of shell nearly smooth
to the naked eye, but marked by very fine radiating raised lines ; perforations rather
large. In the interior of the dorsal valve the loop is short and simple, rendered annular
by the tmion of the oral processes. Length 2J inches, breadth 2 inches, depth 1 inch
4 lines.

Mab. A single specimen of this fine species was dredged on the 25th of March, 1873,
by the ' Challenger ' Expedition off Culebra Island, to the north-west of St. Thomas, in
the West Indies, depth 390 fathoms. It was also obtained in some abimdance by the
Erench expeditions of the ' Travailleur ' and ' Talisman ' in 1882 and 1883, near the
western coast of Africa. It is alluded to by Prof. A. Milne-Edwards in the ' Comptes
Rendus de 1' Academic des Sciences,' tom. xciii. Nov. 1881, and has also, according to
Dr. P. Eischer, been dredged off the coast of Spain.

* " On the Histology of the Test of the Class Palliobranchiata,"' Traus. Royal Irish Academy, vol. xxiv.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 33

Obs. This is the largest species of Tercbratulina with whicli I am acquainted, eitlier iu
the recent or fossil condition.

16. Teeebratulina Crossii, Davidson. (Plate III. iigs. 4-6.)

Terebrutulina Crossei, Davidson, Journal do Conchyliologie, vol. xx\. ]>. lOH, pi. vii. fig. 1, 1882.

Shell large, elongated oval, longer than wide ; valves almost equally convex, mesial
fold and sinus scarcely indicated ; dorsal valve feebly auriculated ; beak of ventral valve
sliglitly incurved, obliquely truncated by a rather large foramen, margined in part by
the umbo and by two small lateral deltidial plates ; surface of valves covered with
numerous fine radiating strise, at times almost obsolete, and crossed by concentric lines
of growth. Colour light yellowish or light salmon. Loop short, not quite a third or
fourth of the length of the valve. Length 2 inches 1 line, width 1 inch 8 lines, depth
1 inch.

Ilab. This magnificent species occurs in Sagami Bay, Japan, where it was dredged by
Dr. L. Doderlciu. The locality is situated iu the neighbourhood of station No. 232 of the
* Challenger' Expedition, only a little nearer the coast, and in about 100 to 250 fathoms.
Dr. Doderlein, who kindly lent me the fine series of Brachiopoda procured by himself in
tliat locality, tells me that the sea-bottom is covered with mud, stones, and fragments
of volcanic origin, with abundant animal life of astonishing variety, and that there is
no better locality for dredging-purposes in Japanese waters.

Obs. I became first acquainted with this fine species in 1882, M. II. Crosse having
kindly forwarded a specimen he had received from Japan, which I subsequently described
and figured in his valuable ' Journal de Conchyliologie.' Soon after I was able to
purchase from Mr. G. B. Sowerby another good specimen of the same shell, and subse-
quently two other fine examples were lent to me by Dr. Doderlein. I have given figures
of three of the specimens. It does not appear to be a very rare species in the locality
where it is found.

I may also mention that no single locality has hitherto afforded a larger or more varied
assemblage of specific forms of Brachiopoda than the waters that surround the Japanese
islands, Corea, and the neighbouring coast of China. I have been able from those seas to
examine and describe the following species : —

1. Terehratuhi or TerehratuUna DalU, I)a.\\ihon. , 14. Terebruidla frontalis, l>.lu\i\cnAor^.

:>.

Davidsoni, Adams.

TerebratuUna Crossii, Davidson.

caput-serpentis , Linne.

japonica, G. B. Sowerby.

(5. Ctimiiiyi, Davidson.

7. radiata, Reeve.

8. Waldheimia Raphaelis, Dall.

9. Grayi, Davidson.

10. Tert'bratidia siiitzbcrijmsis, Davidson.

11. Blanfordi, Dunkcr.

12. coreanica, Reeve.

13. Maria-, Adams.

SECOND SERIES. — ZOOLOGY, VOL. IV.

15. Magasellu Adumsi, Davidson.

16. Gouldi, Dall.

17. Megerlia or Ismenia savgiiinea, Chemnitz.

18. Reevei, Davidson.

19. pidchella, G. B. Sowerby.

20. Laquem picta, Chemnitz.

21. rubella, G. B. Sowerl)y.

22. Plutydia aiiomioidcs, Seaeehi.

23. Rhyncltoiiellupsittacea, var. IVoodwardi, Adams.

24. lucida, Gould.

25. Doderlcini, Davidson (a s])ecies covered

with spines).

34 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

26. Crania japonica, Adams.

27. Discinisca stella, Gould.

28. Linciula anatina, Lamarck.

29. Adamsi, Dall.

30. Lim/ula jaspidea, Adams.

3 1 . smaragdina, Adams.

32. lepidula, Adams.

16. Terebrathlina japonica, Sowerby, sp. (Plate III. figs. 7-11.)

Terebratula japonica, Sowerby, Proc. Zool. Soc. 181(3, p. 91 ; Thes. Conch, vol. i. p. 314, pi. Ixviii.
figs. 7-8, 1846; Adams & Reeve, Voyage of tLe ' Samaraiig,' Mollusca, p. 71, pi. xxi. fig. 1, 1848.

Terebratula anyusta, Adams & Reeve, Voyage of the ' Samarang,' Mollusca, p. 71, pi. xxi. fig. 2, 1848.

Terebratiilina japonica, L. Reeve, Conch. Icon., Monogr. of Terebratula, pi. iv. fig. 16, 1860; A. Adams,
Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 98, 1863.

Terebratulina caput -sej-pentis, var. japonica, Davidson, Proc. Zool. Soc. 1871, p. 303, pi. xxx. fig. 8.

Terebratulina japonica, Dall, Cat. of the Recent Species of the Class Brach., Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 180.

Terebratulina caput-serpentis , var. japonica, G. Duuker, Index Moll, maris Japouici, p. 251, 1882.

Shell obloug, ovate, alnioud-shaped, widest about the middle, rounded iu front, valves
nearly equally and uniformly convex, no defined fold or sinus ; beak slightly incurved
and obliquely truncated by an incomplete circulai- foramen ; deltidial plates rudimentary.
Auricles in dorsal valve very small, marginal line nearly straight, inclining to the sides
near the hinge. Surface of valves longitudinally striated, striae numerous and radiating,
augmenting in number at intervals through the bifurcation of some of the ribs and by
the interpolation of shorter ones of variable thickness. Valves crossed by concentric
lines of growth. Colour light salmon or nearly white. In the interior of the dorsal
valve the loop is small and ring-shaped. Length 1 inch 4> lines, breadth 1 inch, depth
7 lines.

Ilab. Gotto, 48 fathoms ; Tsusalei, 55 fathoms (Adams) ; Sagami Bay, Japan
(Doderlein).

Obs. This species is remarkable on account of its spindle-like shape ; it is nearest related
to T. Crossii, and easily distinguished from the other recent species of the genus. Lovell
Ileeve says, in his Monograph of Terebratula, that " T. japonica is very closely allied to
T. caput-serpentis and is without doubt its representative in the Corean and Japanese
waters." I must, however, differ from Mr. Ileeve in this matter, although in 1871 I
expressed a similar opinion. Dr. Doderlein, it is true, dredged in Sagami Bay a specimen
which I could not distinguish from Linne's T. caput-serpetitls, but it differs in many
respects from T. japonica, which occurs in the same locality. I am, however, quite
prepared to concur with Mr. Reeve's statement that T. angusta, Adams & Ileeve, is only
a smaller form of T. japonica. Dall places T. ahijssicola, Reeve, T. angusta, Ileeve,
and T. Ctim'mgi, Davidson, among his synonyms of T. jajwnica. Reeve's figures of
T. abyssicola would hardly lead me to consider it a synonym of the above-named species,
and a similar doubt may be entertained with respect to T. Cumingi.

17. Terebeatulina radiata, Reeve. (Plate VI. figs. 9-11.)

Terebratula {Terebratulina) radiata, L. Reeve, Conch. Icoi). pi. iii. figs. 7 a~b, 1860, and Ann. & Mag.
Nat. Hist. 3rd ser. vol. vii. p. 173, 1861.

Terebratulina radiata, Dall, Proc. Acad. Nat. Sci. Philadcl|)hia, p. 180, 1873.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 35

Shell subpeutagoual or ovate, longer than wide, indented in front, fiexuously waved
towards the margin. Dorsal valve convex, anterior half biplicated, a median concave
depression commencing at about half the length of the valve, separating the two rounded
ribs. Ventral valve convex, somewhat flattened along the middle and divided on the
anterior half by a median rounded rib, with concave groove on either side. Beak short,
obliquely truncated by a rather large foramen, completed by a part of the umbo of the
opposite valve and by two small lateral deltidial plates. Surface of valves densely
covered with very fine radiating stria; of unequal width, and increasing in number through
bifurcation and the interpolation of shorter riblets. Colour dirty white, sometimes rayed
with broad pencils of black. Loop short and simple, incomplete when young, but with
age becoming annular through the union of the crural processes. Length 11 lines, by
9 in breadth and G in depth.

Rub. L. E,eeve says " Mr. Cuming possesses two or three specimens, all exactly alike,
procured, he fancies, from the dredgings of Sir E. Belcher in the Strait of Corea." I have
seen and possess a number of specimens of tliis shell, which Mr. Sowerby assures me were
obtained near the Cape of Good Hope, its probable habitat.

Ohs. ]\tr. Lovell Reeve considers this to be a good and well-marked species, and in
this statement I feel disposed to concur. I have seen a great many specimens of the
shell, some as wide as long, others longer than wide, and all presenting a more or less
well-marked biplication. In some exceptional examples there existed also an additional
rib on the lateral portions of the dorsal valve. T. radiata is remarkable, as observed by
Mr. E-eeve, on account of being very often sparingly rayed with black. It is a smaller
shell than T. cancellata, its nearest ally. In some specimens the foramen becomes
complete by the union of the deltidial plates, but this appears to be the exception and
not the rule.

18. Terebkatulixa cancellata, Koch, sp. (Plate VI. figs. 1-8.)

Terebratula cancellata, Koch, in Kiister, Concli.-Cab. vol. vii. p. 35, pi. 24. figs. 11-13, 181-3.
Terebratula, species quajdam ignota, Menke, Moll. Nov. Holland, specim. p. 35, no. 192.
Terebratula cancellata, So-nerby, Tlies. Concliyl. p. 358, pi. Ixxi. figs. 93-95, 1846.
Terebratula [Terebratulina) cancellata, Reeve, Conch. Icon. pi. iv. fig. 13, 18G0.

Terebratulina cancellata, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 179, 1873; Davidson, Report on
the Brachiopoda, Voyage of H.M.S. 'Challenger,' Zool. vol. i. p. 37, pi. i. figs. 11-16, 1880.

Shell rather large, elongated oval, livid brown or light yellowish with darker concentric
bands, widest about the middle, nearly straight in front. Dorsal valve very convex,
flattened longitudinally along the middle, from which the lateral portions slope away at
a strong angle. Ventral valve convex, rather less deep than the opposite one and some-
times flattened towards the front ; l)eak incurved, tapering, moderately produced and
truncated by a rather large foramen, which is very slightly separated from the hinge-line
by a very narrow deltidium, the beak often slightly overlying the um])o of the dorsal
valve. Surface of both valves ornamented with a great number of delicate raised striic
or riblets, increasing in number at various distances from the beaks by the interpolations
of shorter riblets. The surface is also crossed at intervals by fine concentric lines of

36 DK. T. DAVIDSON ON EECENT BRACHIOPODA.

i;;l•o^A'tb. In the interior of tlie dorsal valve the loop is simple and short, and rendered
annular in the adult by the union of the crural processes. Sliell-structure perforated by
canals. Brachial appendages united by a membrane and divided into three lobes, the
central shorter one spirally coiled. Length 1 inch 7 lines, breadth 1 inch, depth
10 lines.

Hab. Kiister informs us that his types were derived from Western Australia. His
figures are not good, and he colours them dark brown; some specimens, it is true,
are of livid brown, but those brought back by the ' Challenger ' Expedition were of a
yellowish colour. It was dredged abundantly by the ' Challenger ' Expedition in 1874
off Moncoeur Island, Bass's Strait, in a depth of 35 to 40 fathoms, sea-bottom mud ;
many of the specimens being attached by their peduncle to Fecten, Cardium, Area,
spines of Cidaris, stones, &c. A dwarfed form Avas also dredged for the first time by
Mr. John Brazier of Sydney, at Old Man's Hat Point, Inner North Head, oft' Port
Jackson, N.S.W., near the rocks, in 7 fathoms, bottom of dead broken shells with coarse
sand and stones ; also at Sow and Pigs Reef, eastern side, Port Jackson, near the rocks,
in 3 fathoms bottom. One example was Ibvmd adhering to a valve of TrUjonia
Lamarckii, Gray, and is the only specimen Mr. Brazier ever found on Trigonla.

Obs. When young T. cancellata is often longitudinally spindle-shaped and oval, but
with age shows more of a straight front. Some of the ' Challenger ' specimens have also
much exceeded in size those figured by Kilster, G. B. Sowerby, and L. Reeve. Tlicre exists
likewise in some exceptional sjoecimens a median depression on the anterior portion of
the dorsal valve, commencing at about the middle of the shell and extending to the front.

19. Terebratulina (Agulhasia) Davidsoni, King. (Plate VII. figs. 1-5.)

Ar/idhasia Davidsoni , King, Annals & Mag. of Nat. Hist. 4tli scr. vol. vii. p. Ill, pi. xi. figs. 1-7, 1871.
Terebratulina Davidsoni, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 180.

Shell very small, elongated triangular, much longer than wide. Dorsal valve about as
wide as long, broadest and slightly rounded anteriorly, more tapering posteriorly,
uniformly and moderately convex without fold, lateral sides of umbo gently auriculated.
Ventral valve pyramidal, rather deeper or more convex than the dorsal one and Avith a
slight mesial depression near the front, beak solid, nearly one third of the length of the
valve, tapering to a small incurved point, area in form of an acute isosceles triangle ;
deltidium long and narrow, closed except at the cardinal termination by the internal
plate, foramen incomplete and notch-shaped, lying close to the umbo of the opposite
valve. Surface of valves radiately striated with about twenty small ribs, of which about
half the number are shorter ones interpolated between the longer ribs. Loop in dorsal
valve short and simple, furnished with long crural spurs. Colour white. Length 3 lines,
by 2 in breadth and 1 in dejith.

Hab. Agulhas bank, South Africa, and obtained from a depth of 45 to 60 fathoms.

Ols. In 1870 several specimens of this elegant lyre-shaped shell were placed in my

hands by Mr. G. B. Sowerby, and having sent them to my distinguished friend Prof. W.

King, he kindly offered to publish a description of the shell under the name of Agidhasia

Davidsoni. Although possessing characters bearing relation to Terebratulina, Prof. King

DE. T. DAVIDSON ON EECENT BKACHIOPODA. 37

arrived at thr opiniou that it could be generically distiuguislied. Tiic chief ditfereuces
are to be found in the shape and character of the beak. " The long narrow form of the
deltidium," writes Prof. King, " causes the area to appear as if divided longitudinally by a
linear groove ; whch part is at once striking and unique. The foramen, which appears like
a notch in the centre of the cardinal edge of the large valve, is made entire 1)y the juxta-
position of the cardinal edge of the small valve. The area is well defined laterally I)y
each of the sutures whicji separate it from the inilexed sides of the beak. The loop
agrees very closely in form and relative size with that of Terebratula vitrea ; perhaps its
crural spurs are more produced. The tubuli apjjcar to run in rows, and to be most
numerous in the ribs, from which they branch olf laterally towards the furrows."
Mr. Dall believes the specimens described by Prof. King to be the young of some species
of Terehratid'mu, but the specimens I have in my possession Avould lead me to consider
them the adult condition of a very remarkable small species.

Uncertain Species.

20. Terebratulina Cumingi, Davidson. (Plate V. fig. 53.)

Terehratulina Cuminyii, Davidson, Proc. Zool. Soc. 18.12, p. 71), pi. xiv. figs. 17-19; Keeve, Coucli.
Icon., Mouogr. of Terebratula, pi. iv. fig. 12, LSGO.

Shell small, squarely ovate, somewhat pentagonal, nearly as wide as long; valves
almost equally convex ; beak small, obliquely truncated by a large incomplete foramen,
deltidial plates disunited, a small ])ortion of the aperture completed by the umbo ;
auricular expansions on either side of the umbo, very small ; valves rather gibbously
convex. Surface ornamented by a great number of minute radiating stria3, augmenting
rapidly by the interpolation of smaller riblets at variable distances from the beaks ; front
margin in ventral valve forming a convex curve, and slightly depressed near the front.
Loop small, annelliform. Colour opaque white. Length 3|, width. 3, dei^th 2 lines.

Hub. Chinese Seas.

Obs. Mr. L. Eeeve says that this is " An extremely characteristic well-defined species.
The radiating ridges do not all diverge together from the beak ; a new ridge com-
mences between each former ridge as the space enlarges to receive it." T. Cuminyi
seems to be distinguished from other species of the subgenus by its size and relative
width and length, being much more convex and globular. In 1871 (Proc. Zool. Soc.) I
thought that T. Cwningi might perhaps be a variety of T. caimt-serpentis, but am now
not of that opinion, for having seen a number of specimens of the Little Chinese shell, I
found them all to be possessed of the same shape and character.

In his " Catalogue of the Itecent Species of the Class Brachiopoda ' (Proc. Acad. jS'at.
Sci. Philadelphia, 1873), Mr. Dall places T. Cumingi among liis synonyms of T.japonica,
but I cannot agree Avith him in this particular.

21. Teeebrattjlina abyssicola, Adams & Eeeve, sp. (Plate V. fig. 54.)

Terebratula abyssicola, Adams & Reeve, Moll. Voyage of the ' Saniarang,' p. 72, pi. xxi. fig. 5, 1850 ;
L. Reeve, Conch. Icon. pi. iv. fig. 14, 18G0.

38 DR. T. DAVIDSON OX EECENT EEACHIOPODA.

" Shell triangularly pear-shaped, orange flesh-colour, radiately obsoletely ridged, ridges
distant, with numerous bifurcated striae coming between them, beak obtusely produced,
foramen rather large, incomplete, deltidium obsolete ; loop short" (Reeve). Length 5,
breadth 4|, depth 2^ lines.

Rab. Cape of Good Hope (dredged at a depth of 120 fathoms by Sir E. Belcher).

Ohs. I have seen three examples only of this species (?), one of which was attaclied to a
specimen of Krauss'ma rubra. In the type ligured by E-eeve there is evidence of a
longitudinal depression along the middle of the dorsal valve, and in an authenticated
example in my possession the riblets seem somewhat fasciculated.

Dall, at page 180 of his " Catalogue of the Recent Species of the Class Brachiopoda "
(Proc. Acad. Nat. Sci. Philadelphia, 1873), places T. abijssicola among his synonyms of
T. Jajionica ; but I fear I cannot concur with my friend in this identification. The Cape-
of-Good-Hope form is evidently more nearly related to T. caput-serpentls than to
T. jafonica. More specimens will have to be examined before a positive conclusion can
be arrived at with respect to its specific claims.

22. Terebratulina ? incerta, Davidson, (Plate VI. figs. 23-25.)

Megerlia (?) incerta, Davidson, Proc. Royal Sec. vol. xxvii. p. 438, 1878; and Report on the Brachio-
poda, Voyage of H.M.S. ' Challenger/ Zoology, vol. i. p. 49, 1880.

Shell small, nearly circular, somewhat broader than long, widest towards the middle.
Hinge-line long, nearly straight or very obtusely angular, rather exceeding two thirds of
the breadth of the shell, with obtuse cardinal angles. Dorsal valve somewhat semicircular,
very slightly convex, most so at the umbo, lateral sides of the umbo auricular, no fold or
sinus. Ventral valve a little deeper or more convex than the opposite one, slightly longi-
tudinally depressed along the middle ; beak short and truncated by an incomplete circular
foramen margined by the umbo of the dorsal valve and by two lateral deltidial plates ;
beak-margins sharply defined, leaving between them and the hinge-line a narrow area.
Surface of both valves marked by numerous fine rounded radiating riblets with concave
interspaces, some of the ribs bifurcating near the front, other shorter ones intervening
between the longer ones at variable distances from the beaks. Valves crossed by
numerous irregular concentric lines of growth. Shell perforated by minute canals.
Colour yellowish white. In the interior of the dorsal valve the cardinal process is long
and narrow ; the loop short and simple. Lengtli 5, breadth 5^, depth 2| lines.

Hab. One young example attached to L'mioims aurifa {?), Brocchi, and two or three
more were dredged by the ' Challenger ' Expedition between Sierra Leone (Africa)
and Eernando de Noronha (South Atlantic) in 1850 fathoms, associated witli Disciniscu
atlantica.

Obs. In 1880, when describing this shell for my ' Challenger ' lleport, I felt very
uncertain with respect to the genus to which it should be referred, especially as I was
unacquainted with the sliape and character of its looj:), and did itot like to run the risk of
opening the shell and separating its valves. Since then a number of specimens having
been obtained during the ' Blake ' Expedition, Mr. Dall was able to examine the loop,
which he found to be simple and short, as in Terebmtida or Terebratulina ; the lateral

DR. T. DAVIDSON ON EECENT BEACHIOPODA. 39

portions of the umbo are decidedly auricular, and the character ol' the radiating
riblets would, he thinks, warrant us in classing the shell in the last-named subgenus.
It appears to be a good species.

23. Terebkatulina Mtjrrati, Davidson. (Plate VI. figs. 15-17.)

Terebratvla Murrayi, Davidson, Proc. Roy. Soc. vol. xxvii. p. 437, 1878; and {Terebratulina murrayi)
Report of the Braehiopoda, Voyage of H. M.S. ' ChaUengcr,' Zoology, vol. i. p. 39, pi. i., 1880.

Shell small, obscurely trigonal, about as broad as long, widest anteriorly, tapering
posteriorly, white ; surface of valves marked with about seventeen rounded ribs, of which,
in some specimens, a few are due to the interpolation of smaller and shorter ribs between
the longer ones, the whole surface crossed also by fine concentric lines of growth.
Hinge-line obtusely angular. Ventral valve a little deeper than the dorsal one, beak
very slightly incurved, foramen rather large and incomplete, margined laterally by small
deltidial plates. In the interior of the dorsal valve the loop is simple. Length 2,
breadth 2 lines.

Hah. Dredged by tin; ' Challenger' Expedition in 1871, lat. 38° 35' S., long. 177° 50' W.,
near Kermadoc Island, soutli of Fiji Islands, in a depth of 600 fathoms.

Obs. .Some eleven examples of this small shell were dredged by the ' Challenger '
Expedition, and none exceeded the dimensions above given. It varied a good deal with
respect to the character of its ribs ; in some they were all simple, while in others smaller
and shorter ribs were interpolated here and there between the longer ones. The crura
likewise in some examples in the younger individuals were disunited. In 1879 I sent a
specimen to Mr. Dall for examination, and he wrote me, saying that " by devoting about
half an hour to this little shell, I have cleared away all the animal matter, leaving the loop
perfect. You will see at once that it is a young Terehratidimi. I suspected this before
I could see the loop, from the character of the punctuations, which, you will recollect, is
peculiar to the group." I had also previously ascertained that the loop is simple, and
that the mantle rises from the bottom of the shell near the loop and adheres to its sides,
as was so well illustrated by E. Deslongchamps in TerehratiUina caput-serpentis.

21. Terebratulina tuberata, Jeffreys, sp. (Plate VI. figs. 18-20.)

Terebratula tuberata, Jeffreys, MoUusca of the ' Lightning' and 'Porcupine' Expeditions, 1868-70,
Proc. Zool. Soc. 1878, p. 401, pi. xxii. fig. 2.

Shell somewhat triangular, broadest and rounded anteriorly, tapering posteriorly,
longer than wide. Dorsal valve semicircular ; hinge-line nearly straight, shorter than
the Avidth of tln^ shell ; vahe moderately convex and somewhat compressed, lateral sides
of umbo auricular. Ventral valve rather deeper than the dorsal one; beak pointed, very
little incurved ; area triangular ; foramen oval-shaped and incomplete, margined anteriorly
by the umbo of the ventral valve, laterally by small deltidial plates. Surface of valves
traversed by about twenty radiating ribs, of which some are shorter and interpolated
between the longer ones. Valves crossed likewise by numerous equidistant concentric
raised lines, sometimes slightly projecting and prickly in the young. In the dorsal valve

40 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

the crural processes are separated in the young, arched in tlie adult. Colour dirty white.
Length 4, lireadth 3, depth 2 lines.

Obs. This small shell was discovered by T)r. J. Gwyn Jeffreys, who described it as a
small or young specimen of TerebraUila, which he had obtained during the ' Porcupine '
Expedition in 1870, at a depth of 795 fathoms; and he adds that Prof. Loven bad lent
him a perfect example from the Josephine Bank off the Straits of Gibraltar, di-edged iu
340 to 430 fathoms. Since then several larger and more adult examples were also
obtained by the French dredging expeditions in 1882 and 1883, off the western coast
of Africa, at a depth of about 4787 metres, and off Morocco and Sahara (' Talisman '
Expedition), in 300 to 1261 fathoms.

25. Teeebratulina teigona, Jeffreys, sp. (Plate VI. figs. 21, 22.)

Terebratula trigona, Jeffreys, Mollusca of the 'Lightning' and 'Porcupine' Expeditions, 18fi<S-70,
Proc. Zool. Soc. 1878, p. 402, pi. xxii. fig. 3.

Shell small, ovate, broadly rounded anteriorly, tapering posteriorly, moderately
convex, semitransparent between the ribs and glossy ; beak short, foramen rather
large, incomplete, lateral deltidial plates small ; hinge-line obtusely angular. Sur-
face of the valves marked by about eleven simple rounded ribs, of which the three
central ones are the largest. Coecal tubuli numerous. Margins gently curved and
scalloped in front. Surface of valves marked with numerous equidistant raised lines.
Loop short, simple, and semicircular. Colour clear white. Length scarcely 2 lines,
breadth 1 i.

Obs. We know so very little about this so-called species that its specific claims cannot
])e substantiated. I have only seen a single living specimen, that dredged by Mr. Saville
Kent in Marshall Hall's yacht ' Noma' off the coast of Portugal, in about 500 fathoms.
Dr. J. Gwyn Jeffreys, who described the shell in 1878, says : — " It may perhaps be
immature ; but I cannot identify it with the young of any other species." In this I
feel disposed to agree with Mr. Jeffreys, as I examined the specimen with great
attention while drawing the figures for his paper.

Genus WALDHEIMIA, King, 1850*.

This excellent genus was founded in 1850 by Prof. AV. King for those Terehratulce
in which the dorsal valve was jn-ovided with a long deeply reflected loop, having its
crura attached to the hinge-plate, as is seen in the recent type Terebratula jlavescens,
Lamarck. In the same year Prof. King proposed a genus Macandrevia for a shell with
a similar loop, in which the umbonal cavity of the ventral valve is furnished with two
dental plates, passing somewhat perpendicularly from tlie dental prominences to the
surface of the valve, the umbonal cavitv in the dorsal valve lieing also furnished with

o

* In 1840, four years jirior to the p\ililication of King's name WaJdheimia for a Eraohiopod, the same name had
heen given by Brulle to an insect ; and both Prof. J. Hall and E. Deslongchamps question whether it can consequently
be retained for a Brachiopod,

DK. T. DAVn)S(1N OX EECEXT BEACHIOPODA. -tl

similarly directed iiUites, aud for this geuus he selected the recent Terehralida craniuni.
Miiller, as his type.

In 1880 M. Douville proposed a genus Neothyris for another recent species with a
similar long loop, of Mhich the Terebratula lenticularis, Deshayes, would constitute the
type.

I cannot, however, hut consider these so-termed genera to he very nearly conne(!t<Ml
and as mere moditications of Waldhcimia, and not sufficiently important to warrant theii-
separation into distinct genera.

After a long examination and much thought, I determined to retain the following ten
species and one uncertain one : —

1. It'ald/iei/nia flavescens, Lamarck

2. kergmdenensis, Davidson.

.3. Grayi, Davidson.

4. sept i (/era, Loven.

5. Rupluu'lis, Dall.

0. Wnldheimia floridana, Pourtalcs,
7. vvnosa, Solander.

<S. ■ leniicularis , Deshayes.

9. [Macundrevla) craniam, Miillcr.

10. ( ) tencra, Jetfreys.

Uncertain : Waldheimia IVyviUii, Davidson.

The characters of hotli Waldheimia and Macandrevia will he found fully recorded in
our descriptions of W. flavescens and W. cranium.

Calcareous spicula are absent or almost so in the species above named. Numerous
metamorphoses or changes take place in the shape or development of the loop during;' thr
different stages of its growth, as will he fully described in the sequel.

26. Waldheimia flavescens, Lamarck, sp. (Plate VII. figs. G-19.)

Terebratula flavescens, Valenciennes apud Lamai'ck, An. sans Vert. vol. vi. p. 24G, 1819.

Terebratula australis, Qnoy & Gaimard, Voyage de I'Astrolabe, Zool. p. 551, pi. Ixxxv. figs. 1-5, 1831.

Terebratula incurva, Quoy & Gaimavd, loc. cit. p. 551, pi. Ixxxv. tigs. 11 & 12, 1834.

Terebratula australis, G. B. Sowerby, Thcs. Conch, p. 349, pi. Ixix. figs. 25-33, 1846.

Waldheimia australis. King, English Permian Fossils, Pal. Soc. p. 145, pi. xx. figs. 10-12, 1849.

Terebratula australis, Davidson, Classification of Recent Brachiopnda, Ann. & Mag. Nat. Hist. 2ii(l
scr. vol. ix. p. 3U5, 1852.

Waldheimia Jlavescens, Davidson, Brit. Foss. Bracli. vol. i. p. 64, figs. G & 7, 1853 ; R. Owen, David-son's
Mon. Pal. Soc. vol. i. chapter 1, 1853.

Waldheimia australis,?). Woodward, A Manual of the Mollusca, p. 216, figs. 113 & 111, 1854; Gratiolet,
Etudes Anatomiqucs sur la Terebratula australis, Journal de Concliyliologie, 1857; A. Hancock, On
the Organization of the Brachiopoda, Phil. Trans. Royal Soc. vol. 148, p. 791, 1858.

JJ'aldheimia flavescens, H. & A. Adams, The Genera of Recent Mollusca, vol. ii. p. 575, vol. iii. pi. cxxx.
fig. 3, 1858.

Terebratula {Waldheimia) flavescens, L. Reeve, Monogr. of Terebratula, Conch. Icon. pis. 1 & 2,
fig. 1 a, b, 1860.

Waldheimia australis, Huxley, An Introduction to the Classif. of Animals, p. 28, fig. 10, 1869.

Waldheimia flavescens, Dall, Amer. Journ, of Conch, vol. vi. p. 108, 1870, and Proe. Acad. Nat. Sci.
Philadelphia, 1873, p. 181 ; Tenison Woods, Proe. Roy. Soc. of Tasmania, 1877, p. 57 ; Douville, Bull.
Soc. Geol. de France, 3« ser. pi. vii., 1879 ; Davidson, Report on the Brachiopoda, Voyage of H.]\I.S.
' Challenger,' Zool. vol. i. p. 41, pi. iii. figs. 10-12, 1880; Zittel, Handbuch der Palaontologie, pp. 645

SECOND SEKIES. — ZOOLOGY, VOL. IV. 6

42

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

& 702, 1880 ; E. Deslongchamps, Etudes critiques sur les Brachiopodes, pp. 172 & 177, 1881 ; Davidson,
Pal. Soc. Brit. Foss. Brach. vol. v. p. 323, 1884.

Shell longer thau wide, ovate or subpentagonal, broadest about the middle, straight
in front, yellowish or light brown. Dorsal valve convex, sometimes flattened from
about the middle of the valve to the front ; ventral valve rather deeper and more convex
tlian the opposite one, with a slightly raised longitudinal flattened elevation or fold
along the middle. Beak moderately incurved, truncated by a circular foramen, some-
wliat separated from the hinge-line by adeltidium ; beak-ridges sharply defined. Surface
of both valves from the beaks generally smooth up to a certain age, then radiating and
irregularly plaited, some ribs being shorter than others, the central one straight, those on
tlu> lateral portions of the valves somewhat curved. Shell-structure perforated by canals.
In the interior of the dorsal valve the loop is long and simple ; after being attached to
the hinge-plate and its crural processes given off, the principal stems are outwardly

Fis. 3.

Fig. 4.

Waldheimiajlavescens. Interior of both Valves, enlarged.
Fig. 3. Interior of the ventral valve : /, foramen ; d, deltidium : t, teeth ; a, adductor impressions (=occlusors
of Hancock); c, divaricators ( = cardinal muscles of King = muscles diducteurs principaux of Gratiolet) :
c , accessory divaricators ( = muscles diducteurs of Gratiolet) : h, ventral adjusters ( =ventral peduncular
muscles, or muscles du pedoncule, paire superieure, Gratiolet) ; 6', peduncular muscle.

Fig. 4. Interior of the dorsal valve : c, c , cardinal process : h, h', hinge-plate ; «, dental sockets ; I, loop ; q, crura ;
.^ a, «,, adductor impressions ; m, septum.

curved, and on reaching to about three fourths of the length of the valve become
reflected. The median septum extends along the bottom of the shell from under the
hinge-plate to a little beyond one third of the length of the valve. Brachial or labial
appendages largely developed and united to each other by a membrane. The principal
lateral branches commence on either side of the mouth, curving outward and facing
the bottom of the smaller valve, extend to within a short distance of the front ; then
becoming suddenly bent back upon themselves to within a short distance of the
mouth, are by an elegant semicircular curve directed towards the centre of the larger

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 4:{

valve, and form the commencement of the shorter spiral central lobe. Dimensions very
variable, a large well-shaped example measured — length 1 inch 7 lines, breadth 1 inch
4 lines, depth 1 inch.

Hah. Waldheimia fiavescens { = aus(rcd!s) was picked up in great numbers by thr
' Challenger ' Expedition on the 3rd of June, 1874, at Port Jackson, N. S. W., on the
shore, and in from two to ten feet depth of water. Mr. John Brazier, who has dredged
extensively in the seas adjoining New South Wales, has kindly sent me specimens from
Point Piper, Port Jackson, found under stones in clusters like grapes during low spring-
tides, also on Os/i'ca glomerata, Gould, with a specimen of Kraussina Lamarcldano
on the inside ; a young or smooth variety on a piece of shell with Ismenia or Mecjerlift
pulchella, from the inner north head of Port Jackson, at 10 fathoms, on a bottom of
sand and broken shells ; likewise from Bottle and Glass Rocks, Port Jackson ; and also
from off Shark Point, Port Jackson, at a depth of 14 fathoms. Quoy and Gaimard
found this species, in 1834, in immense numbers at Port Western, Bass Strait. Tliey
observe that hundreds were brought up at each haul of the dredge, either grouped
among themselves, or attached to other shells ; also at Port Jackson, in four feet of
Avater. Prof. Beete Jukes collected any number while boating in South Australia,
among the reefs at Port Jackson ; indeed this is one of the commonest species in the
locality. The Rev. Tenison Woods observes, in his ' Census of the Marine Shells of
Tasmania,' that Waldheimia jlavescens is found off all South Australia, but only on the
north coast of Tasmania.

Obs. I have nothing much to add to my description of this well-known species given
in the ' Challenger ' Report. The shell has received four or five different specific
names, but the best known are those oi jlavescens, Lamarck, and uustraUs, Quoy. In
1819, Lamarck having become blind, Valenciennes described for Lamarck the species
in question, under the names of Terehmtula flavescens and T. dentata ; but he gives
no figures of his species, and upon inquiring from Valenciennes, in 1882, I found that
it was to a specimen from Port Jackson tliat he gave the name o'i Jlavescens. Tlic
larger number of malacologists have preferred the name of austraUs, given to it iii
1834 by Quoy and Gaimard, Avho gave a number of good illustrations of the shell,
including that of the loop *. Quoy's T. recurca is no more than a short variation in
form of a specimen in which the beak is much incurved ; and the same may be said of
Lamarck's T. dentata.

Waldheimia flavescens is very variable in shape and ribbing. In some examples the
beak is longer or more produced than in others, and the foramen much more distant
from the hinge-line in some individuals than in others. Some specimens are also more
or less subpentagoual, others elongated oval, some lozenge-shaped and circular. The
valves in some examples are quite smooth in the young, and very often up to an advanced
stage of growth. In other specimens the ribs are simple or bifurcating, and of differeni
size and strength on the same individual, and begin to rise close to, or at some distance
from, the extremity of the beak and umbo. In PL VII. some of these modifications
in shape and character have been illustrated.

* Voyage dc TAstrolabo, Atlas, pi. 85 (18:34).

6*

44 DE. T. DAVIDSON ON KECENT BRACHIOPODA.

The loop passes likewise through a series of metamorphoses from the very young
state up to the period when it assumes the simple adult Tfaldheinda-chareicter, as has
been so elaborately described and illustrated by Herman Friele in the case of TFald-
heimia septlgera and Wcddheimia (or Macandrevia) cranium.

The intimate shell-structure of JValdheimia ficwescens has been minutely described and
admirably illustrated by Dr. W. B. Carpenter, in his chapter " On the Intimate Structure
of the Shells of the Brachiopoda," which he kindly prepared in 1853 for vol. i. of my
' Monograph on British Fossil Brachiopoda,' and to which the reader is referred. But we
may here mention that he found the perforations in 7?^. jiavescens to average a diameter
of about 8^0 inch, and the distance of their centres about j^. Three of his illus-
trations have been given in PI. VII. figs. 17-19.

In 1869, in vol. xxiv. of the Transactions of the Royal Irish Academy, Prof. W. King
gave an excellent description of the shell-structure of the species under description, in
which he observes that Quekett, in 1850, discovered that the extremity of the caecal
appendages, as they are now^ generally called, is more or less flattened or disk-shaped, and
encircled with a fringe of exceedingly minute radiating lines or membranous filaments.
Prof. King adds, " In position and arrangement the ^laments belonging to the termina-
tions of the ca?cal appendages so completely agree with the radiating lines which intersect
the apertural rims of the perforations, as to leave no doubt on my mind that the latter
are tubular and enclose the former." The shell of JF. Jiavescens and its intimate shell-
structure is also described by Gratiolet, in his admirable memoir " Etudes anatomiques
sur la Terebratule australe," Journal de Conchyliologie, 1857. He says, at p. 214 of his
memoir, that the shell, when divested of the foreign objects that generally cover its
surface, is of a tolerable transparency. One notices in it, besides the concentric lines of
growth, diverging costae which give to the sharp edge of the valves an undulated appear-
ance ; examined with a lens, its surface is finely granulous, so much so, that one might
think it formed of veiy fine granulations ; but this aj)parent granulation is due to a
multitude of microscopic perforations with Avhich the shell is riddled. These perforations
are, besides, very irregularly disposed on parallel bands which intercept quadrilateral
spaces. He adds that the substance of the shell is formed of small calcareous prisms,
somewhat attenuated at their extremity and disposed in parallel layers, which give
to the fractured shell a fibrous aspect ; these elements are closer together towards the
edges of the shell than in their central poi'tions.

The soft parts of the animal of Waldheimia Jiavescens have been admirably described
and elaborately illustrated by several eminent anatomists. First by Owen in 1853, in
the Introduction to vol. i. of my work on ' British Fossil Brachiopoda ; ' subsequently,
in 1857, by Pierre Gratiolet, in his memoir above quoted, and in the following year by
Albany Hancock, in his classical memoir " On the Organization of the Brachiopoda "
(Phil. Trans. Boy. Soc. vol. cxlviii.). To these works the reader is referred for more
complete anatomical details than we are able to reproduce in this monograph.

The body proper is small when compared with the size of the shell, and has both its
valves lined by a delicate bilobed integument or membrane, termed the ' pallium ' or
mantle ; this secretes the shell and is fringed with horny bristles. The mantle is composed

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

45

of an outer and an inner layer, between wliicli are situated tlie blood-channels or lacunae.
There are four principal arterial trunks in the dorsal lobe of the mantle, and these run
direct to the front and bifurcate at intervals (see PI. VII. figs. 15, 16 d). The aperture
of the mouth is situated in the middle line between the pallial lobes, and on each side
of it is a prolongation of the body provided with ciliated teatacula.

The muscles have been minutely described by the three anatomists above named.
Five or six pairs are connected with the opening and closing of the valves, or with their
attachment to, or movements upon, the peduncle. First of all the adductoi- or occlusor
consists of two muscles, which, bifurcating near the centre of the cavity, produce a large
quadrangular impression on the internal surface of the dorsal valve. The function of

FiE

Waldhwnia JldvcKCtns (after Hancock).

M, ventral Talvc : X, dorsal valve ; J, loop : r, mouth ; :. extremit)- of intestine : a, adductor : f, divaricators ;
(■', accessory divaricators; h, ventral adjustors; h\ peduncular muscle; h" , dorsal adjustors ; P, peduncle.

this pair of muscles is the closing of the valves. Two other pairs have been termed
dkarlcatoi's by Hancock, and have the function of opening the valves. The divaricators
proper arc stated by the same eminent authority to rise from the ventral valve, one on
each side, a little in advance of and close to the adductors, and after rapidly diminishing
in size, become attached to the cardinal process, a space or prominence between the sockets
in the dorsal valve. The accessory divaricators are a pair of small muscles which have
their ends attached to the ventral valve, one on each side of the median line, a little
l)ohind the united basis of the adductors, and again to the extreme point of the cardinal
process. The two pairs of muscles, apparently connected with the peduncle and their
limited movements, have been minutely described by Hancock as having one of then-
extremities attached to this organ. Tlie dorsal adjustors are attached to the ventral
surface of the peduncle, and are again inserted into the hinge-plate of the smaller valve.
The ventral adjustors are considered to pass from the inner extremity of the peduncle,
and to become attached by one pair of their extremities to the ventral valve, one on
each side of and a little behind tlie expanded base of the divaricators. The function ot
these muscles is not only that of erecting the shell, but also that of attaching the

46 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

peduncle to the shell, and thus controlling the steadying of it upon the peduncle. These
details and the figure taken from Hancock will sufficiently explain the functions of the
different muscles. Hancock describes the peduncle as composed of a dense muscular,
semi-cai'tilaginous mass of a cylindrical form.

The nature of the muscles has also been well described and illustrated by Owen,
Gratiolet, and more recently by Van Bemmelen, in his anatomical memoir ' On the
Structure of the Shells of Brachiopods and Chitons ' *.

Owing to the strong and tiglit interlocking of the valves of Waldhelmia flavescens and
other species, by means of curved teeth and sockets, the Brachiopoda would seem to open
their valves very slightly.

At p. 806 of the admirable memoir already alluded to, Hancock says that in Waldlieimia
flavescens and in other forms of the genus, the " loop originates in the hinge-plate in
two necks or processes, — the crvira, from which two jioints project downwards, called the
crural processes. The upper or dorsal members of the loop, passing from these two
lateral necks, stretch forward for about two thirds the length of the valve, then bend
towards the ventral valve, and turning back upon their course, are united across the
median line, a short way in advance of the crural processes. The lateral portions of
the loop are curved a little outwards. The whole of this calcareous support, in-
cluding the crura and crural processes, is a product of the inner lamina of the dorsal
pallial lolje. This lamina, with the exception of a portion at each side, which is con-
tinuous with the similar lamina of the ventral lobe, forming with it the anterior wall of
the perivisceral chamber, is turned downwards and forwards, and extends as far as the
transverse portion of the loop. It then divides into two lobules, one passing to the
anterior extremity of each of the lateral portions of this calcareous support, binding
together the dorsal and ventral members. The loop in its sinuous course follows tlie
margins of this bifurcated pallial process, and lies imbedded in its substance.

" The arms themselves taper to fine jioints, having taken their origin at each side of the
mouth, which is situated at the back of the pallial chamber in a central position, opening
downwards. They pass outwards and forwards in connection with the calcareous loop and
the pallial lobules, running along the outer edge of the dorsal member of the former ;
they then turn back upon the reflected or ventral part of it, and on reaching the trans-
verse portion bend inwards and doubling sharply upon themselves, again advance and
go to form two vertical spirals turned towards the dorsal valve. The spirals are placed
parallel to each other, and throughout the coil, consisting of two or three turns, they
are united across the median line by a rather wide, stout, semicartilaginous membrane,
which is attached behind the transverse portion of the loop."

The labial appendages have been magnificently illustrated by Owen in plates 1 & 2
of his chapter on the ' Anatomy of the Terehratula ' already referred to. They are also
minutely described and illustrated by Gratiolet in his ' Etudes anatomiques sur la
Terebratule australe,' 1857.

These appendages are, in TF'aldheimia flavescens, as well as in other species of the

* ' Over den Bouw der Schclpcn van Brachiopodeii en Chitonen,' Leiden, 18S2, and of which an English note will be
found in the Ann. & Mag. Nat. Hist. 5th ser. vol. xi. p. '37Q, 1S83.

DR. T. DAVIDSON ON RECENT BRACHIOPODA.

47

genus, a pair of very remarkable organs, eminently cbaraetcristie of the Brachiopoda.
'J'hey are often and more correctly termed labial appendages, on account of each member
being a prolongation of the lateral portions of the lips of the margins of the mouth.
They occvipy the larger portion of the cavity of the shell in front of the visceral chamber ;

FiK. 0.

Fis;. 7.

Wahlheimia Jlavescen.t.

Vi". 6. Interior of dorsal valve, to show the position of the labial appendages. (A portion of the fringe of the
cirri has been removed to show the brachial membrane and a portion of the spiral extremities of the
arms.) Enlarged.

Fig. 7. Longitudinal section, with a portion of the animal. (/, 7;, brachial appendages ; a, adductor : c, c', divari-
cator muscles ; s, septum ; v, mouth ; :, extremity of alimeutarj* tube. (The peduncular muscles have
been purposelj- omitted.) Enlarged.

and are mainly composed of a membranous tube fringed on one side Avith long flexible
hollow cirri, which are not capal)le of being protruded in those families and genera in
which they ai"e folded back upon themselves and supported T)y a skeleton, as in JFald-
heiiJiia. Hancock says (Phil. Trans, vol. cxlviii. p. cxliii.) that the arms or labial appendages
" are normally composed of a membranous tube or canal bearing a semicartilaginous
grooved ridge. The latter stretches from end to end of the former, and gives support
to the fringe of cirri. As far back as the commencement of the spirals the arms are as
above stated ; but for the entire length of the lateral portions of the loop, wiiere the
arms are doubled ujion themselves, and Avhere, of course, two tvibes or canals might have
been expected, thex'e is only one, the two having, as it were, coalesced. These large canals
at the roots of the arms are continuous with those of the spirals, and terminate in blind
sacs, one at each side of the oesophagus, close to the mouth. On making a transverse
section of this part of the arm, the enlarged terminal portion of the brachial corn' i-
seen connected with the external edges of the dorsal and ventral mem])ers of the loop ;
and the pallial lobule, stretching between the inner edges, forms a sort of inner tube.
This inner tul^e opens widely into the perivisceral chambei*, is in fact a prolongation of

48

DE. T. DAVIDSON ON RECENT BRACHIOPODA.

this chamber, aud terminates at the anterior extremity of the lateral portion of the loop,
forming what may be designated as the brachial pouches. The cirri are tindoubtedly
contractile to some extent, and are also endowed Avith the power of motion individually,
as proved by the observations of Mr. Barrett. It would likewise appear that the
entire fringe of cirri can be elevated or depressed, there being ample means provided for
tlie purpose." Many other highly important details have been recorded by Owen,
Gratiolet, and Hancock, which I regret I am unable to reproduce.

Mr. Hancock states, at p. 811 of his memoir, that "the mouth, in all the Brachiopods,
as previously stated, is situated in the brachial groove, at the posterior junction of the
arms, and is a simple, oval, transverse slit, or orifice devoid of any armature. In
JF. australls there is, however, a slight bulging-out of the posterior wall immediately
within the orifice, which is somewhat like the valvular appendage of Phimatella, and may
perhaps assist in swallowing. The alimentary tube assumes the form of a siphon bent in
the vertical plane, the arch turned towards the dorsal valve ; the oesophagus represents
the short, the stomach and intestine the long arm."

There is no anal outlet in this species. According to the same author, the mesentery
is divided into two portions, the dorsal and ventral : it sustains the alimentary canal in
the vertical plane, and altogether with it divides the anterior portion of the chamber
into lateral halves. The gastro-parietal bands are three in number, two lateral and one
median.

In W. flaveseens, Mr. Hancock says, " the genitalia are formed of thick bands,

Fig. 8.

Lateral view of the Viscera of WaJdheimiaJiavescms, after Hancock,
n, anterior layer of mantle ; b, posterior layer; c, anterior walls of the body between the mantle-lobes ; (7, arms;
p, gullet ; q, stomach, with cut biliary ducts of the left side ; r, right hepatic mass : s, intestine ending
ca'cally between j and k ; v, so-called " auricle " of the right " pseudo-heart," the left being almost wholly
removed ; w, pyriform vesicle fixed to the back of the stomach, and probably performing the function of a
true heart ; r, oesophageal ganglia. (This figure is also given by Huxley on page 28 of his ' Introduction to
the Classification of Animals,' 1869.)

DR. T. DAVIDSON ON EECEXT BRACIIIOPODA. 49

somewhat convoluted and branched ; they are of a full yellow colour, and are thrust
into the trunks and main branches of the great pallial sinuses" (p. 817).

" The heart is a simple, unilocular, pyriform vesicle, suspended from the dorsal aspect,
and projects freely into the perivisceral chamber " {loc. cit. p. 831).

Prof. Huxley, in his ' Introduction to the Classification of Animals,' 18G9, says that
" The precise characters of the true vascular system of the Brachiopoda probably
require still further elaboration than they have yet received ; and the same may be
said, notwithstanding the valuable contributions of P. Midler and of Lacaze-Duthiers,
of their development ; but the shell, the pallial lol^es, the intestine, and the nervous and
the atrial systems, afford characters amply sufficient to define the class " (p. 30). He also
says (p. 29), " In all Brachiopoda which have been carefully dissected, a singular system of
cavities and canals situated in the interior of the body, but in free communication \\i\\\ the
surrounding medium, has been discovered. This, which I shall term the ' atrial ' system
(from its close coi'respondcnce with the system of cavities, which has received the same
name in the Ascidians), has been Avrongly regarded as a part of the true vascular system,
and the organs by which it is placed in communication with the exterior have been
described as ' hearts.' There are sometimes two and sometimes four of these ' pseudo-
hearts,' situated in that part of the body-wall which helps to bound the pallial chamber.
Each pseudo-heart is divided into a narrow, elongated, external portion (the so-called
' ventricle '), Avhich communicates, as Mr. Hancock has proved, by a small apical aperture
with the pallial cavity ; and a broad, funnel-shaped, inner division (the so-called ' auricle '),
communicating, on the one hand, liy a constricted neck with the so-called ' ventricle,'
and on the other, by a wide, patent mouth, with a chamber which occupies most of the
cavity of the body proper, and sends more or less branched diverticula into the pallial
lobes. These have been described as parts of the blood vascular system; and the
arterial trunks, Avhich have no existence, have been imagined to connect the apices
of the ventricles with vascular networks of a similarly mythical character, supposed
to open into the branched diverticula. In fact, as Mr. Hancock has so Avell shown in
his splendid and exhaustive memoir published in the ' Philosophical Transactions ' for
1857, the true vascular system is completely distinct from this remarkable series of
' atrial' chambers and canals, the function of which would appear to be to convey away
excretory matters and the products of the reproductive organs, which are developed in
various parts of the walls of the atrial system."

In an exquisitely beautiful enlarged illustration in his ' Anatomy of the Terebratiila,'
Owen represents the bracliial aponeurosis and spii*al arms of JJ^aldheimia Jlavcscens,
showing the central part of the nervous system, with the brachial and the beginning
of the pallial nerves.

27. WALBHEniiA VEXOSA, Solaudcr, sp. (Plate YIII. figs. 1-5 ; Plate IX. fig. 1.)

Anontia venosa, Solander, G. Dixon, A Voyage round the World, Appendix no. 1, p. 355 and fig., 1789.
Terehrutula glohosa, Valenciennes, apiid Lamarck, An. sans Vert. vol. vi. j). 2ifi, 1819, with
reference for figui-e to Encyclop. Method, p. 239, figs. 5 a, b, 1789.

Terebratula dilatata, Valenciennes apud Lam., An. sans Vert. vol. vi. p. 215, 1819.

SECOND SERIES. — ZOOLOGY, VOL. IV. 7

50 Dli. T. DAVIDSON ON EECENT BEACHIOPODA.

Terebrafula Gaudichaudi, Blainville, Diet. Sci. Nat. 1824.

Terebratula globosa, Anton, Verzeichniss der Couchylien, p. 23, 1839.

Terebratula eximia, Philippi, Kiister, Conch.-Cab. vol. vii. p. 39, pi. 2. figs. 9 & 10, 1843.

Terebratula Fontaineana, d'Orbigny, Voy. Amer. Merid. vol. v. p. 675, pi. 85. figs. 30 & 31, 1847.

Terebratula {Waldheiinia) ylobosa, Heeve, " Mouogr. of Terebratula," Conch. Icon. pi. ii. fig. 3, 1860,
and pi. vi., 1861.

Terebratula {Waldheimia) globosa, Reeve, Ann. & Mag. Nat. Hist. vol. vii. p. 173, 1861.

Terebratula [Waldheimia) dilutata, Reeve, Conch. Icon. pi. vi. fig. 2, 1861.

Terebratula physema, Valenciennes, MS. ; Reeve, Conch. Icon. pi. vi. fig. 23, 1861.

Waldheimia venosa, Davidson, Ann. & Mag. Nat. Hist. 3i'd ser. vol. viii. p. 36, 1861.

Terebratula venosa, Cunningham, Voyage o£ H.M.S. Nassau, Trans. Linn. iSoc. vol. xxvii. p. 488, 1871.

Waldheimia venosa, Dall, Amer. Journ. of Conch, vol. vi. p. 109, 1870, and Proc. Acad. Sci. Phila-
delphia, p. 182, 1872.

Shell large, longitudinally oval, ovately globose, widest about tlie middle, longer than
wide. Dorsal valve convex, with a shallow flattened longitudinal depression or sinus
along the middle, commencing at about half the length of the valve and extending to
the front. Ventral valve a little more convex than the opposite one, with a slightly
produced and flattened mesial fold commencing near the beak and extending to the
front ; beak moderately incurved and truncated by a rather large circular foramen, with
thickened margin and completed anteriorly by a deltidium in two pieces ; beak-ridges
sharply defined. Surface of valves smooth, marked only by concentric lines of growth.
Shell-structure punctate. Colour light olive-horny. Loop long and reflected ; cardinal
process and hinge-plate large. Under the hinge-plate a rather strong mesial septum
extends to a third or a little more of the length of the valve, and on either side on the
bottom of the shell are situated the adductor and other muscular scars. Length 3 inches
2 lines, breadth 2 inches 8 lines, depth 2 inches.

Sab. Tierra del Fuego ; Falkland Islands (Dixon) ; Port William, Falkland Islands
(B. J. Sulivan) ; Coquimbo ; off Cape Possession in about 15 fathoms ; Port Famine
(Cunningham).

Obs. This is the largest recent Brachiopod at present knov\^n, and its history has been
somewhat confused. It was, however, well described and figured in 1789 by Captain
George Dixou, who says, at p. 356 of his work ' A Voyage round the World ' : — "At Falk-
land Islands we met with a curious kind of shell of the Anomia genus of Linnaeus, of
which, though the species are numerous in a fossil state in most parts of the world, few
have been discovered recent, or fresh from the sea. Only one of this sort was before
known in Europe, which was brought over by my late worthy commander, the much
regretted Captain Cook, in his first voyage round the world. It was in the Portland
Museum, and was named by the late celebrated Dr. Solander, in his MSS. description of
the shells of that splendid cabinet, Anomia venosa ; the specimen is now in the
collection of Mr. Calonne, of London. This kind (as do all that are propei'ly of this
genus) adheres to coral rocks by a ligament that comes from the animal through the
hole in the larger valve. The internal structure peculiar to the shells of this genus
is very singular, and consists of two testaceous rays, which commence near the
hinge in the lesser valve, where they adhere ; from w hence, leaving the shell, they

DE. T. DAVIDSON ON RECENT BEACHIOPODA. 51

proceed to ncai' the edge, then bend towards the other valve, and turn back to their
commencement, where they nnite. This internal part is very delicate, and breaks upon
the smallest touch, but is thicker in the parts nearest to the large valve. The shell takes
its name from certain parts of the animal, which run in a branched form along the inside
of the shell, which being held to a strong light, or a candle, gives a beautiful veined
appearance. The outside is smooth and of a pale brown colour. The specimen from
which the engraving was made, is in the private collection of Mr. George Humphrey,
dealer in natural curiosities, London " (Plate VIII. fig. 1).

In 1819 Valenciennes briefly described the same species by the name of Terehratula
globosa, referring at the same time to plate 239, fig. 2, of the ' Encyclopedic M6thodique '
for a figure of his species. The figure in the ' Encyclopedic ' is not well drawn ; but the
specimen from which it was taken is in the collection of the Jardin des Plantes, and was
lent by M. Valenciennes to Lovell Reeve, who gave a good figure in plate vi. fig, 3 of his
' Monograph of Terehratula ' in 1861. In 184<3 the same species received the name of
T. eximla from Philippi and Kiister ; that of T. Fontaiueana from d'Orbigny, and to a
large specimen of the same form in the collection of the Jardin des Plantes, measurin"-
2^ inches in length, M. Valenciennes gave the MS. naxaeoi physema. Under this name
it is also described and figured by Reeve in his ' Monograph of Terebratnla ' in 1861. The
specimen was brought from Coquimbo by M. Gaudichand in 1833 (Plate VIII. fig. 6). In
his description of this specimen Mr. L. Reeve observes that " It would be satisfactorv if
the species could l)e confirmed by the discovery of further specimens. It is intermediate
in its characters between T. dllatata and T. globosa, inclining I'ather to the latter species,
of which it may prove to be a colossal broadly inflated variety," and this I have no doubt
it is.

It was Valenciennes, however, who descril^ed and gave the names to all the recent
Brachiopoda published in 1819 in the ' Animaux sans Vertebres ' of Lamarck, that
celebrated zoologist having unfortunately lost his sight at that period.

I am quite convinced, after the inspection of the original specimen and figure of
T. dilatatu, Val., as well as from Reeve's figures in plate vi. fig. 2 of his ' Monograph '
(the type having been lent to him by M. Valenciennes out of the collection of the Jardin
des Plantes), that it is only a smaller and more transverse form of Waldheimia veuosa.
Several other specimens of the same form which have also passed through my hands
have tended to confirm this view, which had already been expressed by Mr. W. H, Dall
in his memoir published in the 'American Journal of Conchology,' vol. vi. p. 109,
where he notes also that the T. Gaudichamli of Blainville is another synonym of
W. venosa. In a paper I published in the 'Ann. & Mag. Nat. Hist.' for August 1867,
I described and figured the largest example of TF. venosa that had been discovered, which
had been dredged in 1843 or 1814 by Rear-Admiral B. J. Sulivan at Falkland Islands,
in the same locality whence the type of the species had been procured by Dixon.
Admiral Sulivan informed me, when lending me his specimen, that the depth at which
the animal lived was from 6 to 7 fathoms, the bottom on which the shell lay being a
compact quartzose sand only, as no mud ever came up with the dredge, although a
stiflf muddy clay underlies the sand, on which anchors hold very firmly.

7*

52 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

JFaldheimia venosa, like all its congeners, is variable in external shape. The foramen
is larger in some specimens than in others. As is the case with W. lenticularis when
quite young and sometimes until half its growth, W. venosa is either almost circular
or transversely oval. W. dilatata seems to be a half-grown individual with a large
foramen (Plate IX. fig. 1).

IF. venosa has often been confounded with Laqnetts calif ornicus of Koch, both species
attaining large dimensions ; but the loop in both is entirely different, and in the last-
named species the beak is much more incurved, the foramen very small, and separated to
a greater or less extent from the umbo of the dorsal valve by a deltidium in two pieces.

In Vol. clxviii. of the Phil. Trans., 1879 (Transit of Venus Exped.), Mr. Edgar A. Smith
mentions Waldhelniia {Terebratida) dilatata, Lamarck, as having been obtained at Obser-
vatory Bay at a depth of 4 fathoms. I may, however, remark that the ' Challenger '
Expedition did not bring back a single specimen of Solander's species.

28. "Waldheimia lenticularis, Deshayes, sp. (Plate IX. figs. 2-13.)

Terebratula lenticularis, Deshayes, E.evue Zoologique par la Soc. Cuvierienne, p. 359, 1839, and Mag.
de Zoologie, d'Anatomie comparee et de Paleontologie, p. 41, figs, a, b, c, d, 1841 ; G. B. Sowerby,
Thes. Coucliyl. vol. i. p. 360, pi. Isxii. figs. 108-110, 184G; Davidson Ann. & Mag. Nat. Hist. 2nd ser.
vol. ix. p. 305, 1852; L. Reeve, Monogr. of Terebratula, Conch. Icon. pl. 2. fig. 4, I860.

IValdheimia lenticularis, Gray & Woodward, Brit. Mus. Cat. of the Brachiopoda, p. 58, 1853 ; Dall,
Proc. Acad. Nat. Sci. Philadelphia, p. 182, 1873.

Neothyris lenticularis, Douville, Bull. Soc. Geol. de France, 3" ser. t. vii., 1879.

IValdheimia lenticularis, E. Deslougchamps, Notes sur les Modifications h. apporter jl la Classe des
Terebratulidae, pl. xvii. figs. 5-7, 1880.

Shell large, orbicular, elongated oval, globose, longer than wide, thick, rounded
laterally, less so in front. Dorsal valve uniformly convex or slightly depressed at or close
to the frontal margin. Ventral valve deeper, and a little more convex than the dorsal
one and slightly longitudinally carinated ; beak rather sharply incurved, overlying the
umbo of the opposite valve, and truncated by a small circular foramen, separated from
the hinge-line by a wide, narrow, concave deltidium in two pieces ; beak-ridges very
sharply defined. Surface smooth, marked by concentric lines of growth, punctate.
Colour pinkish red or yellowish horny. Loop simple, long, and reflected ; cardinal process
rather large and prominent ; under it a mesial sejitum extends to about one third of the
length of the valve on either side the adductor and other muscular scars. Length
2 inches 2 lines, breadth 1 inch 11 lines, depth 1 inch 3 lines.

Sal). Lives abundantly attached to rocks in the Straits of Eouveau, New Zealand, in
15 fathoms. It occurs also in great numbers in the Pleistocene rocks of New Zealand.

Capt. F. W. Hutton, in his ' Catalogue of the Tertiary Mollusca of New Zealand,' p. 35,
1873, quotes the following localities : — " Wanganui, The Deans, Waipara, Waitotari,
Chatham Islands." The fossil is also well described and figured by Prof. E. Suess from
tlie ' Novara ' Expedition, in his fine memoir " Eossile MoUusken und Echiuodermen aus
Neu-Seeland," Palajontologia, p. 56, pl. x. figs. 3, 4 (18GG).

Obs. I have in my possession a very large series of specimens of this fine species from

DR. T. DAVIDSON OX EECENT BRACHIOPODA. 53

2 up to 23 lines iu length. When young and up to nearly half its growtli the shell is
almost circular and broadest anteriorly, ta^jering at the beak, and nearly as wide as long ;
with age the shell becomes elongated and gibbous.

I have carefully observed and drawn the modifications that take place in the shape of
the loop, of which I give some illustrations in Plate IX. figs. 11, 12, 13. My figures
agree well with tliose published by M. E. Dcslongchamps in his ' Etudes Crititjues ' above
quoted, and they do not diftur from those peculiar to other species of the genus. In a
specimen two lines in length the whole loop is small, not extending further than to
about half the length of the valve, its principal lamellae, as well as the reflected portion,
becoming attached to the extremity of the upper sides of a perpendicularly elevated
septum, as in Ilagasella. After a time the septum becomes less elevated, the principal
stems of the loop acquire greater length, and give ofi" at about half their length a
horizontal lamella, which is also fixed to the septum, as in Tcrehratella ; later on this
horizontal lamella detaches itself from the septum, the principal stems of the loop
become more separate, and the reflective portion assumes the appearance of that of a
fuU-grown Waldheimia.

Waldheimia Icnticiilaris was well described and figured by Desliayes in 1841, and also
by G. B. Sowerby and L. Reeve. It has had the good fortune to preserve the same
specific name, although located iu the genera Terehratula, Waldheimia, and Neotliyris.
As observed by Reeve, in his ' Monogr. of Terehrahila,' " Were it not that the habitats of
this and the preceding species [Terebratiila {Waldheimia) glohosa'] are well authenticated, it
would be difficult to believe that there is any specific difference between them. This is
rather lighter [with an] inflated growth, and the colour is remarkable, but the characters
n other respects are the same in detail throughout. The foramen is probably as small
as in T. globosa ; in all the specimens of T. Icnticularis that I have seen it is more or less
eroded, according to the circumstances of its attachment. The loop is precisely the same
in both species." There are, however, differences between W. venosa and W. lenticularis
which must not be overlooked. In well-preserved specimens of the last-named shell the
foramen is small, iu fact much smaller than in W. venosa, and separated from the hinge-
line by a well-developed deltidium in two pieces, in this respect more nearly resembling
Laqneus californicus. The beak is more incvirved, and the dorsal valve more uniformly
convex. The colour is also very difi'erent in the two species. It is also a smaller shell.

29. Waldheimia kerguelenensis, Davidson. (Plate X. figs. 7-17.)

Waldheimia kerr/uelerms, Davidson, Proc. Roy. Soc. vol. xxvii. p. 437, 1878, and {IV. kerguelenensis)
Report on the IJrachiopoda, Voyage of H.M.S. ' Challenger/ Zool. vol. i. p. 40, pi. iii., 1880.

Shell OA-ate, ventricose, longer than wide, light yellowish white, smooth. Dorsal valve
most convex near the umbo, a slight mesial depression commencing about the middle of
the valve extends to the front, and is more or less distinctly margined on either side by a
faint raised line or ridge ; front line slightly depressed or nearly straight. Ventral valve
rather more convex than the opposite one, and more or less distinctly keeled by the
presence of a wide, convex, but slightly raised fold, which corresponds with the depression
in the dorsal valve. Beak moderately produced and incurved, truncated by a small

54 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

circular foramen laterally margined by two small disunited deltidial plates. Cardinal
process prominent, and formed of three distinct parts. In the interior of the dorsal
valve, and under the incurved extremity of the umbo and hinge-plate, there rises a
wide short and massive septum, and on either side on the bottom of the valve the
muscular scars are visible. Loop delicate, elongated and reflected. Shell-perforations
numerous. Length 2 inches, breadth 1 inch 4 lines, depth 1 inch 2 lines.

Hah. It was dredged by the ' Challenger ' Expedition in great numbers ofi" Marion
Island, west of Kerguelen Island, at a depth of 100 fathoms. Two examples oi Platydia
anomioides were attached to one of the specimens. Also at Balfour Bay, near
Kerguelen Island, in 20 to 60 fathoms, south of the same island at a depth of 150 fathoms.
Three examples of Wiynclionella nigricans, var. pixidata, were obtained with it.

Obs. I have examined several specimens of the animal that had been dredged alive by
the expedition, as well as of the shell from 1 line up to 24 lines in length. Some examples
were nearly circular and as broad as long, bvit the larger number were of an elongated
oval shape, becoming ventricose with age. When the peduncle by which the shell
adhered to foreign bodies was sufiiciently long, and did not interfere with the animal's
limited movements, the beak was much incurved and the foramen small ; but in most
cases the peduncle was exceedingly short, and the shell came into contact with the hard
bodies to which it was moored, causing erosion and the consequent enlargement of the
foraminal aperture. The animal closely resembles in general character that of Wald-
heimia Jlavescens, so admirably described by Owen and Hancock.

Some specimens bear a certain resemblance to Waldlieimia lenticularis ; but this last
is smaller, more ovate or regularly oval, and more especially in the young and inter-
mediate stages of growth. Having forwarded two examples for Mr. Ball's examination,
he informs me : — " I have carefully compared it with d'Orbigny's Waldheimia Fontaineana,
and feel more sure than ever of the correctness of my reference of his species to
Waldheimia venosa. It is certainly not this fine species ( Waldheimia kerguelenensis),"
though it is possibly identical with the shell erroneously described and figured by G. B.
Sowerby, at p. 359, and plate xxi. figs. 99-101, of his ' Thesaurus Conchyliorum,' in
1846, as the Terebratula glohosa, Lamarck. The specimen Sowerby figured under that
name (said to have been taken from Lamarck's collection) is now in the British Museum,
and Sowerliy was certainly mistaken in stating " It agrees perfectly with the represen-
tation in the ' Encyclopedic Methodique,' tab. 339. fig. 2 " !

30. Waldheimia Gbayi, Davidsou. (Plate X. figs. 1-4.)

Terebratula Grayi, Davidson, Proc. Zool. Soc. 1852, p. 7(\, pi. iv. figs. 1-3.

Terebratula [Waldheimia) Grayi, L. V. Schrenck, Reiseii mid Forschungem in Amur-Lande, p. 465,
1854-56.

Waldheimia Grayi, E. Suess, Sitzungsb. Akad. Wissenschaften, Bd. xxxvii. p. 201, 1859.

Terebratula [Waldheimia) Grayi, L. Reeve, Couch. Icon. pi. 2. figs. 5 a, b, c, 1860, and Ann. &
Mag. Nat. Hist. 3rd ser. vol. vii. p. 175, 1861 ; Journal de Couchyl. p. 123, 1861.

Waldheimia Grayi, Carpenter, Rep. Brit. Assoc. 18G3, p. 636.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 55

Waldheimia Grayi, A. Adams, Anu. & Mag. Nat. Hist. 3rd ser. vol. xi. p. {)[), 18G3 ; Davidson, Proc.
Zool. See. p. 30I-, pi. xxxi. figs. 7 & 8, 1871 ; Dall, Am. Journ. of Concli. vol. vi. p. 110, 1870, ami
Proc. Acad. Sci. Philadelphia, 1873, p. 182; G. Duiiker, Index Moll. Maris Japonici, p. 252, 1882.

Shell variable in shape, squarely subpentagoual or subtriaugularly semicircular,
longer or broader than ^vide. Iliug-e-line either nearly straight or very obtusely angular,
shorter or longer than the breadth of the shell ; lateral margins rounded, nearly straight
or gently curved in front. Dorsal valve very moderately convex, somewhat flattened
and more or less longitudinally depressed along the middle. Ventral valve very much
deeper and more convex than the dorsal one ; beak short, bent backwards, nearly straight
or very Little incurved, and obtusely truncated by a large, transversely oval, incomplete
foramen, always more or less eroded, margined anteriorly liy the dorsal valve and by two
small labial rudimentary deltidial plates ; beak-ridges strongly marked, leaving between
them on the hinge-line a wide triangular almost flat area. Surface of valves marked by
a number of strong bifurcating radiating angular costse, of which the central one is
usually the largest. Valves traversed by numerous more or less prominent scale-like
zigzag concentric lines or ridges of growth. Shell-structure punctate. Colour
yellowish, with concentric bands of crimson colour, deeper in tint at or near the
projecting concentric ridges of growth. Proportions very variable. Two large examples
measured : —

Length 1 inch 4 lines, breadth 1 inch 3 lines, depth 10 lines.
1 '^ 17 9

') -■- 3) — J5 )) -■- 5) ' >5 55 ^ 55

In the interior of the dorsal valve the cardinal process is wdde and narrow, the hinge-
plate large, mesial septum strong, extending to abovit half the length of the valve. Loop
long and simple ; the principal stems attached to the base of the hinge-plate extend to
about four fifths of the length of the valve before becoming reflected.

Sab. Hakodadi, Mososeki, Japan, in 7 fathoms (Adams). Strait of Corea (Belcher
and St. John), in 37 fathoms. Dall mentions also Catalina and Monterey.

Obs. This very remarkable and beautifvil shell is, as already stated, very variable in
shape, so much so, indeed, that some malacologists have felt disposed to divide it into
two species ; and, as observed by Dall, it is sometimes hardly possil)le to distinguish it
exteriorly from some specimens of Terebratula transversa, Sow., var. caurina, Gould,
or T. occidentalis, Dall, except by the loop, which in W. Grayi is simple, while in the
others it is three times attached, as in Terebratella.

Prior to 1852, the shells of the species under description had erroneously been referred
to the Terebratula {Krausslna) rubra of Pallas, to which they also bear some external
resemblance ; and it was only after careful examination of the interior calcareous support
of the labial appendages that I discovered that they belonged to two very distinct
genera. As observed by Lovell Eeeve, m his ' Monograph of Terebratula,' the foramen of
the shell naturally becomes more or less eroded and enlarged according to the roughness
with which the creature is liufTetcd about in the place of its attachment, owing to the
shortness of its peduncle. He also observes that the deltidial plates meet in tlie middle
in very young examples, and that the ribs of W. Grayi are not really scaled, but scales

56 DE. T. DAVIDSON OX RECENT BEACHIOPODA.

are formed on them by the overlapping of the concentric lines of growth. The ribs are
also somewhat irregular in some specimens.

Waldheimia Orayi is extremely abundant in its favourite haunts. In Corean waters
it was dredged in great abundance by Admiral Sir Edward Belcher during the voyage
of H.M.S. ' Samarang.' A. Adams and Capt. St. John obtained it in similar abundance,
and say that it could be collected by thousands in certain places where it had been
washed on shore. Mr. Dall has observed that the blood in this species is red.

31. "Waldheimia septigera, Loven, sp. (Plate XI. figs. 1-10.)

Terehratula septigera, Loven, Index MoUuscorum Litora Scandiuavise occidentalia habitantium,
Ofversigt af K. Vet.-Akad. Fovb. 1846, no figure.

TValdheimia septigera, Gray & Woodward, Cat. of Bracli. in the Brit. Mus. p. 59, 1852; Davidson,
Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi. pi. x. fig. 1, 1855; E. Suess, Ueber die Wobnsitze der Bra-
chiopoden, Sitzunsgb. k. Akad. Wissensch. Wien, Bd. xxxvii. p. 200, 1859.

Terehratula [Waldheimia) septigera, Reeve, Monogr. of Terehratula, Concb. Icon. pi. iii. fig. 10, 1860.

Terehratula peloritana, Seguenza, Notizie succinte, p. 19, 1862.

Waldheimia peloritana, Sequenza, Memorie della Soc. Ital. di Scieuze Naturali, voL i. p. -19, pi. vi.
fig. 10, 1865.

Terehratula septula, Jeffreys (not Pbilippi), Brit. Concb. vol. ii. p. 14, 1863.

Waldheimia septigera, Seguenza, Mem. della Soc. Italiaua di ScienzeNat. vol. i. p. 44, pi. vi. figs. 1-10,
1865 ; Bull. Soc. Geol. France, 2nd ser. vol. xxv., 1808 ; Bull. Malacologica Italiaua, anno iii., 1870.

Terehratula septata, Jefl'reys, Proc. Zool. Soc. 1878, p. 407, pi. xxiii. fig. 1 (not Pbilippi) ; G. O.
Sars, Bidrag til Kuudskabcn om Norges arktiske Fauna : Mollusca Regionis ArcticcC Norvcgioe,
Christiania, pi. i. fig. 2, 1878 (not Pbilippi).

Terehratula floridana, Jeffreys (not Pourtales), Proc. Zool. Soc. p. 407, 1879.

Waldheimia septigera, Dall, Bull. Mus. Com. Zool. Harvard, vol. iii. p. 13, pi. 1. fig. 4, pi. 2. fig. 9, and
Proc. of tbe California Acad, of Sciences, p. 182, 1872; H. Friele, "Bidrag til A'estlandets Mollusk-
fauna, Vidensk.-Selsk. Forband. p. 57, pi. 1. fig. 2, 1875, and Tbe Development of tbe Skeleton of tbe
genus Waldheimia, Arcbiv for Matbematik og Naturvidenskab, Bd. ii. p. 380, pi. iii. figs. 5, 6, and
pi. iv. figs. 12-14, 1877; E. Deslongcbamps, Etudes Critiques sur les Bracbiopodes, p. 98, pi. i. figs. 17
& 18, pi. XV. figs. 4-6, and pi. xvi. figs. 1-3, 1884.

Shell somewhat square, ovate or subpentagonal, broadest anteriorly, more attenuated
posteriorly, longer than wide, lateral edges rounded, wide and nearly straight in front,
anterior margin sinuated, corners obtusely rounded anteriorly. Dorsal valve evenly
convex to abovit half its length; anterior half divided into three lobes, the central one
by far the largest and widest, forming a slightly raised, rounded, wide mesial fold.
Ventral valve deeper than the dorsal one, with a wide concave sinus commencing at a
short distance from the beak, and gradually widening until it reaches the front ; beak
incurved and truncated by a rather large circular foramen, completed and separated
from the hinge-line by a deltidium in two pieces ; lateral portions of the beak rounded.
Surface of valves smooth, but marked by numerous fine concentric lines of growth.
Colour light yellowish or greyish white. Shell-structure punctate. Dimensions variable,
two large specimens measured: —

Length 1 inch 8 lines, breadth 1 inch -l lines, deptli 1 inch.
„ 1 „ 8 „ „ 1 „ 1 line, „ 10 lines.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 57

In the interior of the dorsal valve, tlu; eanlinal process is so small that it can hardly
be diirerentiated from the hinge-plate, and from under which a mesial septum extends
to one half the length of the valve. Loop long, simple and reflected, the lamella of the
reflected portion being wide, the principal stems nearly parallel.

Rab. Off Norway, Finmark, &c., in 100 to 300 fathoms. Atlantic coast of Spain.
Dredged by the ' Porcupine ' Expedition at various northern stations, at depths from 75
to 755 fathoms (Jeffreys). In British Seas between Shetland and Faeroe, by Jeffreys
and J. Murray, in 345 to 570 fathoms. A'igo Bay (M'Andrew). Off Marocco and the
Canary Islands (' Talisman ' Expedition) in 331 to 861 fathoms.

Obs. The shell and some parts of the animal have been carefully examined. Mr. Ball
says that its visceral area is very small, the muscular attachments being even smaller
than in Waldheimia floridana. The stomach, produced into a point without diffei'entia-
tion of the intestine, is very much shorter than in W. Jloridaiia.

The development of the skeleton or loop in this species has been well studied and
illustrated in two papers by Herman Friele in 1875 and 1877, and by E. Deslongchamps
in 1S84<. Dr. Gwyn Jeffreys and myself have also followed out the same investigations.
Herr Friele begins by informing us that he has not been able to examine the first stages
in the development of the loop in this species, as he had done for that of Waldheimia
cranmm ; that the youngest examples of W. septigera he has seen measured 1, 2, and 3 lines
in length, and represented the second stage of JF. craii'mm, in which the united lamellte
begin to split apart at the anterior end ; and that the only essential difference at that
age is in the form of the septum, being 4'5 millimetres and 5*5 millimetres respectively.
The next stage he terms the Megerlla stage, the shell having attained 4 lines in length.
In this stage in Waldheimia cranium the lateral walls were broken down by an aper-
ture appearing in the middle of each and widening backwards. In W. septigera the
break occurs, on the contrary, on the posterior end of the walls, and extends in a forward
direction, the similarity at this stage to Terebratella being striking. The connection
between the process of the lamellae and the sejitum is severed in a specimen G lines in
length, and in a specimen 8 lines in length the lamellae are separated and the character
of the loop is that of the adult Wcddhehnia. In Plate XI., figs. 7, 8, 9, TO are from
Friele's memoir, showing the modifications above described.

Waldlieimia septigera was described for the first time by Loven, in 1846 ; but having
neglected to give a figure of his species, the shell was very little known until 1855, when
I gave a figure of it in the Ann. & Mag. Nat. Hist. In 1863, in vol. ii. of his ' British
Conehology,' and subsequently in a paper in the Proc. Zool. Soc, Dr. Gwyn Jeffreys
erroneously maintained that Lov6n's Waldlieimia septigera was a synonym of Philippi's
Terebratnla sepAata, and this mistaken view he maintained to the last. In 1840, Signor
Seguenza, after much trouble and skill, examined the perfect loop in several adult
examples of Philippi's T. septata, and found it to be three times attached, as in Tere-
bratella, while the loop in W. septigera is only twice attached, as in Waldheimia.
The same indefatigable palaeontologist also examined the loop of his Pliocene Tere-
bratula peloritana, and found it to agree with that of Waldheimia septigera, of which
he admits it to be a synonym.

SECOND SERIES. — ZOOLOGY, VOL. IV. 8

58 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

My valued and distinguished friend Dr. Gwyu Jeffreys was again mistaken when he
said, at p. 408 of his paper in the ' Proceedings of the Zoological Society ' for 1878, that
Waldheimia j)eloritana and W.floridana appear to be the same variety of Terebratula
septata. Having had all the developed sjoecimens in my hands, I am able to give my full
support to Prof. Seguenza's statement.

Waldheimia septigera and W. Ilaphaelis are much more nearly related than either of
them are to W. jioridana. Terehratella Ilarice (Adams), from Japanese waters, is also
said by Dr. Gwyn Jeffreys to be possibly a variety of W. septigera (his T. sepdata) ;
but in the small specimen of T. Marice I have been able to examine the loop was three
times attached, as in Terehratella.

Waldheimia septigera, undejc the name of W. peloritana, has been well described
and illustrated by Signor Seguenza, in his Monograph of the Brachiopoda from the
Tertiary def)osits of Messina in Sicily, p. 49, pi. vi. figs. 1-10 (1865). It occurs plentifully
in the UpiJer Pliocene rocks at Gravitelli.

32. Waldheimia Raphaelis, Dall. (Plate XI. figs. 11-13.)

Waldheimia Rapftaelis, Dall, Am. Journ. of Conch, vol. vi. p. 3, pi. vii. figs, a, b, c, d, 1870 ; Davidson,
Ou Japanese recent Brachiopoda, Proc. Zool. Soc. 1871, p. 303, pi. xxxi. fig. 9.

Shell elongated, longer than wide, somewhat subtrigonal, widest about the middle
and anteriorly, tapering posteriorly, nearly straight or gently curved outwardly in front.
Dorsal valve moderately convex, with a very wide mesial fold, commencing at about a
third of the length of the valve, uniformly and gently convex, or divided longitudinally
by a small mesial groove. Ventral valve deeper and more convex than the dorsal one,
with a broad deep mesial sinus commencing at a short distance from the extremity of
the beak, and becoming deeper and wider as it reaches the front margin ; on either side
of the sinus the valve slopes abruptly to the lateral margins. Beak slightly incurved
and truncated by a large circular foramen, separated from the hinge-line by deltidial
plates. Surface smooth, marked only by concentric lines of growth ; punctures oval-
shaped outside, smaller, more distant, and cii'cular on the interior surface of the valves.
Colour light yellowish, with a slight rufous tinge. In the interior of the dorsal valve
tlie cardinal process is small, quadrate, and stout ; under it commences a small septum
that does not reach to quite half the length of the valve. Loop long, reflected portion
broad ; crura much curved at their extremity. Length 1 inch 10 lines, breadth 1 inch
5 lines, depth 1 inch 1^ lines.

Hab. Japanese coast, near Yeddo (Plumpelly and Dall). Sagami Bay, depth 100 to
200 fathoms (Doderlein).

Ohs. I have seen five good examples of this remarkable sjiccies. In Mr. Dall's and
Dr. Doderlein's specimens the fold in the dorsal valve is gently convex throughout ; in a
fine example I obtained from Mr. G. B. Sowerby the fold was probably exceptionally divided
into two lobes by a median groove. The shell is named after Prof. Raphael Plunqielly,
its nearest ally being the Waldheimia septigera of Loven.

Waldheimia septigera, W. Ilaphaelis, and W. Jioridana belong, as was justly remarked
by Mr. Dall, to a peculiar group in the genus Waldheimia, and are specifically distinct.
The first is froin northern European seas, the second from those of Japan, and the third
from the Florida coast or reefs.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 59

33. Waldheimia floridana, Pourtales. (Plate XII. ligs. 1-.5.)

Waldheimia floridana, Pourtales, Bull. Mus. Comp. Zool. Harvard, vol. i. p. 127, 1868; Dall, Bull.
Mus. Comp. Zool. Harvard, vol. iii. p. 12, pi. i. figs. 1-3, 18"1.

Eudesia floridana, Bull. Mus. Comp. Zoiil. arvard, vol. ix. p. 103, 1881.

Shell trians:^ular, widest anteriorly, tapering posteriorly, generally as wide or wider
than long ; anterior margins strongly flexuous. Dorsal valve uniformly convex poste-
riorly, anteriorly divided into three lobes, the central by far the largest, forming a
wide moderately elevated fold ; lateral edges of valves flexuous, anterior corners rounded.
Ventral valve deeper than the dorsal one, with a large wide mesial sinus commencing at
a little distance from the extremity of the beak and gradually widening as it I'eaches the
front ; lateral lobes nearly flat or gently concave, sloping rapidly from tlie outer side of
the fold and sinus to the edsjes of the shell. Beak incurved and truncated by a small
circular foramen, very little separated from the hinge-line by a narrow deltidium in two
pieces ; beak-ridges rounded. Surface smooth. Colour greyish or brownish white with
a slight touch of yellow. Length 11, width 12, depth 8 lines.

In the interior of the doi'sal valve the cardinal process is small, the hinge-plate rather
large, and from under its base a mesial septum of small elevation extends to about two
thirds of tlie length of the valve. Loop simple, very broad and separate anteriorly,
narrow posteriorly. Stomach spherical, with a long cylindrical intestine.

Uah. Very abundant, attached to Plorida Reefs, depth 100 to 200 fathoms, on rocky
1)ottom (Pourtales) ; off Sand Key, 125 fathoms (Sigsbee) ; off Havana, 175 fathoms
(Dall).

Obs. Thanks to the great liberality of Prof. A. Agassiz, I have been able to examine a
large number of specimens of this remarkable and Avell-characterized species from the
dimensions of five up to eleven lines in length. When quite young and up to a some-
what advanced period of its growth, the shell is longer than wide, the fold and sinus
being scarcely indicated in very young examples. Dall, in his excellent description of
this species, states that it belongs to a peculiar group including W. Jloridana, W. septigera,
and W.BaphaeUs; he adds : — "Thus it is seen that the smallest species [^F.j'^orJdrtP/rt] is
by far the widest and most inflated proportionately ; the second species is the flattest
in proportion to its length ; and the third the most elongated."

" The greater portion of the mantle of W. Jioridana is of the most extreme tenuity and
perfect transparency. It is furthermore so closely attached to the shell as to render its
removal intact — even with the aid of acid— a matter of great difficulty. With this excep-
tion, the examination of its anatomy is easy The soft parts are mostly of a translucent

whitish color. The number and disposition of the muscles are similar to those of W. mis-
tralis, already described by various authors. The muscles themselves are of a glistening
tendinous appearance, except at their points of attachment, where they are of a more or
less dark yellowish-brown. The peduncle is moderately long, and the portion which is
external or contained in the foramen is covered with a dark, horny, reddish-brown
membrane or skin, and the attached extremity is trumpet-shaped. Upon opening the
shell in its normal position, the median spires of the brachia are seen to be somewhat
widely separated, and between them is stretclied a flne translucent membrane extending

S*

60 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

forward from the under lip of the mouth and foUowing the downward curve of the
median lohes. In this great extension of this membrane this species differs from T. caput-
serpentis and W. australis, in which species the cirrhi of the median lobes touch at their
extremities, and are separated by only a very narrow sti"ip of membrane between their
bases, so that the appearance is almost as if there was but a single broad band of cirrhi
in the median line. This intervening membrane in ordinary specimens of W. fioridana
is about "24 of an inch in width at its narrowest visible portion. The upper and lower
bands of cirrhi in the lateral loops are also much more widely separated by a similar

membrane than in W. australis The spiral portion in the middle lobe makes

about two complete turns The mouth is, as usual, just in front of the posterior

junction of the brachial bands, and is in a rather long flexuous groove, tlie edges of

which are of a dark brown colour, and somewhat thickened The oesophagus is

about half as long as the intestine, and has a slight curve, of which the convexity is
anterior ; it is transversely flattened close to tlie mouth, and is a little compressed
laterally, behind that portion. It is of a nearly uniform calibre throughout. It has
quite a thin lining membrane, which becomes thicker, though still smooth, in the
stomach, and quite thick and longitudinally plaited in the intestine. The stomach is
well differentiated from the alimentary canal and intestine, and is of an oval shape. It
is embraced by the hepatic digitations, which are of a greenish-yellow color, and empty
into the stomach by four ducts. The orifices of these ducts are of a compressed oval
shape, obliquely inclined, and the anterior pair, which correspond to the right and left
anterior congeries of hepatic digitations, are twice as large as the posterior pair, which

similarly correspond to the anterior lobes or bunches of digitations The intestine

is twice as long as the oesophagus, of uniform calibre, and perfectly straight. It leaves
the stomach abruptly without any dilatation of the portion adjacent to the latter
organ, and reaches aljout half-way to the dorsal valve. The heart is situated behind the
junction of the stomach and intestine. The termination of the intestine is abruptly
rounded off and not at all pointed. It is entirely closed, and is upheld by the mesentery.
It is also of a much darker color than the rest of tlie alimentary canal, being of a
deep chestnut brown hue."

" The great pallial sinuses and their ramifications in W. florkkma are of much less
extent and disposed in quite a different manner from that which obtains in W.
australis. The hfemal pallial system consists essentially of four branches which are
remarkable for their straight course and the paucity of their ramiticatious. The neural
pallial system is very similar, wdth a greater number of small sinuses about the peri-
visceral cavity, but in both lobes the narrowness and small extent of the sinuses, as
compared with those of other species, is very marked, and the same is true with regard
to the ovaries. But a very few exceedingly delicate spicukTe were observed in the floor
of the greater sinuses. The lieart consists of a very minute pyriform vesicle situated
behind the intestine at its junction with the stomach, and sending one vessel in the
hsemal direction along the median line of the stomach, and another on each side laterally.

The ovaries are very limited in extent and principally confined to that portion

of the sinuses which surrounds the visceral cavity, only their ultimate extremities entering

DR. T. DAVIDSON ON llECENT BRACHIOPODA. Gl

the larger branches of the great sinuses The ova were visible in all stages of

growth. Those floating free in the lacunes were nearly spherical, and of a flesh-colour ;
their substance seemed of a granular consistency, due perhaps to the action of the spirit
in which they were preserved. The immature ova were pyriforin, attached to the ovary

by their pointed ends No sperraatophora; or spermatozoa were observed in any

of the specimens examined. The oviducts are situated as in IV. aiistralis. The lining-
membrane of their trumpet-shaped portion was drawn into tiiin plicie. Their apices

were teat-shaped, with very small oriflces The setae are very slender and tine,

irregularly marked with transverse lines, but smoother towards their outer ends. They

protrude from their follicles, hardly more than one third of their length The

mantle edge was brownish and seemed to have a slightly villous epithelium."

I have reproduced this long extract from Mr. Dall's admirable memoir, as I have done
in similar cases from the works of other authors, because all that relates to the animal of
different species of the same genus is of the utmost importance. The animals of species
of the same genus no douljt agree in their general character, but often differ considerably
in their respective details, and these differences should always, when possible, be carefully
noted. The animal of every species should also under favourable circumstances be
anatomically examined and described.

In his " Contributions to the Fauna of the Gulf Stream at great Depths " (Bull. Mus.
Comp. Zool. vol. i. p. 127), Count L. T. de Pourtales informs us, in his description
of Waldheimiafloridana, i\vd.i " Very young specimens are flatter, rounder, and have a
straight margin ; they could scarcely be distinguished from the young of Terebratulu
cubensis, if it was not for the loop and septum seen by transparency. There is also some
variety of form in tlie old; in some specimens the length is greater than the breadth,

and there is considerable diversity in the sinuosity of the frontal margin It is

always associated with Terebratula cubensis, the latter being still more common (in the
proportion of about three to one), and making its first appearance in 100 fathoms.""

34. Waldueimia (Macandrevia) cranium, Miiller, sp. (Plate XII. tigs. 11-23 ; Plate
XIII. figs. 1, 2.)

Terebratula cranium, Miiller, Zool. Danica; Prodronius, p. 249, no. 3U0(J, 177G.

Anomia vitrea, Cliciuuitz ? (not Born), Conch. -Cub. vol. viii. p. 97, t. 78. figs. 707 & 709, 179.').

Terebratula cranium, Moutagu, Trans. Liun. Soc. vol. xi. p. 188, tab. xiii. fig. 2, 1811 ; Turtou, Conch.
Diet, of British Isle.s, 1819.

Terebratula vitrea, Fleming (not Born), Phil, of Zool. vol. ii. p. 498, pi. iv. fig. 4, 1822 ; Schumacher
(not Born), Essai iriai nouveau Systeme des Hab. des Vers Testaees, p. l;3;3, pi. ix. fig. 1, 1817.

Terebratula eutlnjru, Philippi, Enum. Moll. Siciliie, vol. ii. p. 68, tab. xviii. fig. 8, 1814.

Terebratula cranium, C. B. Sowerby, Thes. Conch, vol. i. p. 354, pi. Ixx. figs. 60-G2, 18 10 ; Loven, Index
Moll. Scandinaviie, (Efvers. K. Vet.-Akad. Forh. p. 183, 1846 ; Davidson, IMonogr. Brit. Foss. Bracli. Ter-
tiary Species, vol. i. pi. i. fig. 8, 1852, and Ann. & Mag. Nat. Hist. 2ud ser. vol. xvi. pi. x. fig. 8, 1855.

Terebratula (jlabra, Ijcaeli, Brit. j\Ioll. p. 359, pi. xiv. figs. 3, 4, 5, 1852.

Terebratula subvitrea, Leach {teste Reeve).

Waldheimia cranium, Barrett, Report Brit. Assoc. Glasgow, 1855, p. 107 ; Hancock, Phil. Trans. Roy.
Soc. vol. cxlviii. 1858; Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. Wissensch.
Wien, p. 200, 1859.

62 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

Mocandrevia cranium, King, Proc. Dublin Univ. Zool. and Bot. Assoc, vol. i. p. 261, 1859.

Terebratula {Waldheinda) cranium, Reeve, Concli. Icon., Monogr. of Terebratula, pi. iii. fig. 6, 1860.

Te^'ebratula cranium, Jefi'reySj Brit. Conch, vol. ii. p. 11, and vol. v. p. 163, pi. xix. fig. I, 1863.

Waldheimia euthyra, Seguenza, Pal. Mai. Class. Brach. p. 46, pi. v. figs. 6-14, 1865.

Waldheimia cranium, Dall, Am. Journ. of Conch, vol. vi. p. 110, 1870; Friele, Yidensk. Selsk.
Forhandl. pi. i. fig. 1, 1875, and Archiv for Mathematik og Natnrvidenskab, pi. i. figs. 1-4, pi. ii.
figs. 5-7, pi. iii. figs. 1-4 and 7, 1877 ; G. O. Sars, Mollusca Region. Arct. Norveg. (Christiania) p. 10,
tab. i. fig. 3, 1878; Jeffreys, Proc. Zool. Soc. 1878, p. 405.

Macandrevia cranium, Douville, Bull. Soc. Geol. de France, 3'' ser. vol. vii., 1879; K. A. Zittel,
Handb. der Palaontologie, p. 703, 1880 ; E. Dcslongchamps, Etudes critiques sur les Brachiopodes,
pi. xiii. figs. 13-16, pi. xiv. figs. 4-9, and pi. xv. fig. 5, 1884.

Shell lenticular or ovate globose, longer than Avide, broadest about the middle, lateral
margins rounded, antex'iorly subquadrate or rounded, sometimes much thickened at the
margins. Dorsal valve evenly convex, without fold or sinus. Ventral valve deeper than
the dorsal and evenly convex ; beak slightly incurved, short, and truncated by an in-
complete circular foramen, margined anteriorly by the umbo and by two rudimentary
deltidial plates, which are in many specimens absent ; beak-ridges not very sharply
defined. Surface smooth, marked only by concentric lines of growth. Colour yellowish
white or light horny. Shell-perforations separated by interspaces of about equal size.
Dimensions variable — length 1 inch 1 line, width 10 lines, depth 7 lines. In the interior of
the dorsal valve there is no defined cardinal process or mesial septum, but two deviating
septa commence under the extremity of the umbo and extend to a little more than
one fourth of the length of the valve ; loop long, attached to the base of the hinge-
plate, and extending to about four fifths of the length of the valve before becoming
reflected *. In the interior of the ventral valve the teeth are supported by strong
dental plates.

Hah- W. cranium is an abundant shell near the coast of Norway and in the northern
seas. It was dredged on several occasions by R. MacAndrew and L. Barrett between
Vigten Islands and the North Cape, in 25 to IGO fathoms, attached to stones; only abun-
dant at Omnsesoe. Dr. Gwyn Jeffreys dredged it many times during the ' Lightning'
and 'Porcupine ' Expeditions off the Faeroe Islands, in 161 and 208 fathoms, and as deep
as 690 fathoms during the ' Porcupine ' cruise in 1869. MacAndrew obtained it outside
Vigo Bay in 30 fathoms, Vl'allich in Greenland, and the Marquis de Polin and Dr.

* So delicate and brittle is the loop at the point where the primaiy lamellte become reflected, that both Dr. J.
(fwyu Jeffreys and Dr. W. B. Carpenter for some time entertained the mistaken opinion that at that point they were
naturally disunited. This led Dr. Jeffreys to remark on p. 13 of the second volume of his ' British Conchology ' : —
'• Having carefully cleaned the inside of a specimen of T. cranium, containing the dried remains of the animal, with
a weak solatiou of potash, and examined several other perfect shells of different ages, I could not perceive the least
ajtpearance of a loop, which is so evident in 7'. austraJix. The lamellar processes in the lower valve of T. cranitim
are eijual in length, and end in sharp points. They may be compared to the chariot-blades used by the ancient
Sevthiaus, and they somewhat resemble the falcifonu apophyses of Teredo and Pliolds. In the young of T. craminn
these processes are extremely short. Their airaugcment and .shape are so dissimilar in species closely allied in other
respects, that I should be inclined to consider their importance, as characters of generic distinction, somewhat
doubtful.'' It was some considerable time before I could convince my distinguished friend that the loop of Wcdd-
heimia cranium differed hut little from that of W. Jlavcscens.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 63

P. Fischer off the south-west of France, iu from 5 to 650 fathoms. It was also dredged
by Prof. Sars, Friele, and others off the Norwegian coast ; east coast of Shetland
(Fleming and Jeffrey.s) ; North Hebrides by Dr. W. K. Carpenter and Sir WyvUle
Thomson, in 170-050 fathoms, &c.

Waldheimia cranium occurs fossil under the name of Terehratula euthyra, Philijjpi,
in the Upper Pliocene rocks of Valle Lamato in Calabria, and near Catancaro near
Reggio, at Gravitelli, Rometto, and other places near Messina in Sicily (Seguenza).
Prof. Sars and others quote it from the glacial and post-glacial deposits of Norway.
Waldheimia cranium has been recorded as from Ualifax in Nova Scotia by the late
Mr. Willis ; but I have been informed by Mr. Dall, Mr. Whiteaves, and others,
that w'hat he took for the shell under description w^as a specimen of Terebratella
■spitzbert/emis.

Obs. This species, its shell, animal, and different stages of development have been
carefully investigated and admirably described by several competent zoologists. It
has, however, been classed iu the genera Terebratula, Waldheimia, and Macan-
drevia. In 1859, Prof. W. King considered that the species should be separated from
Waldheimia, on account of the deviating septa and want of a mesial septum in the
dorsal valve, as well as bv the absence of dental lamina in the ventral one. I, how^ever,
with Mr. Dall, question Avhether the differences brought forward are of sufficient value
to warrant us in admitting it as a separate genus ; they are, at most, we think, sub-
generic differences.

To Herman Friele we are indebted for a most valuable and important investigation
into the modifications assumed by its loop, from the very youngest age up to the adult
condition, which I now propose, in part, to transcribe from his memoir published in
1877. I also reproduce some of his figures on Plate XII., regretting that space will not
permit me to give them all. He says : — " The earliest stage at which a coherent apophy-
sary system of the Waldheimia cranium is observed, has a size of a little less than three
millimetres [1 line], the haemal valve being two millimetres [Plate XII. fig. 16]. Two
long thin lamellae project from tbe crura, connect with a filiform septum and run
together in an acute angle iu front, where they unite. By the connection of the lamelke
two close-set walls are given off, which by a refieetion form a tube, the posterior end of
which is closed. The size of the haemal valve has reached 2-5 millim., but the state of
things remains the same, save that both the loop (or the tube) and the lamellce have
expanded. [See PI. XII. figs. 17, 17 «] a the lamellae, b the two issuing vertical walls,
or the lateral walls of the tube, c the closed tube (or the loop).

" The first visible change occurs hi/ an opening in the closed end of the tube [figs. 18,
18 a]. The united lamellas then begin to split apart at the anterior end. The haemal
valve has now attained the size of 4-5 millim. A continuous expansion of the loop-
complex causes a perforation in the lateral walls [PL XII. fig. 19], and the septum becomes
thinner and thinner. The next sizes observed were 5*2 millim. and 5-6 millim. (haemal
valve) [PI. XII. fig. 21]. The same characteristics as those seen in [PL XII. fig. 19]
are still in the main prevailing, but the connection with the septum is broken off, and
there remains but a little lump of the latter at the bottom of the valve. The wedge-

64 DR. T. DAVIDSOX ON RECENT BRACHIOPODA.

formed separation of the lamellae have progressed so far [PL XII. fig. 21], that only a
short hand of connection is left betAveen them ; the apertures in the walls have likewise
widened, and a narrow slip is all that still combines the lower and the upper parts.

" The stage of growth illustrated liy [PL XII. figs. 19-21], may properly be designated
tlie Megerlea Stage, and it would be difficult to recognize in this state either the
individual described in [PL XII. figs. 16 and 17], or the fully developed Waldheimia.
In order to become a mature Waldheimia the band between the lamel-processes and
the loop must vanish and the connected lamellae must separate." In another figure, which
we have not reproduced, " the hinder connection between the wpper and lower parts is
completely severed, but the lamelte are still, though slightly, connected." In the nest
stage the connection is cut, PL XII. fig. 22, and in fig. 23 we have the most mature Wald-
heimia cranium. Here Friele gives figures from one fifth of a line in length up to one
line, the smallest of Avhieh is no bigger than a dot.

Waldheimia cranium has sometimes been confounded with Liothyris vitrea, to which
it occasionally bears some general external resemblance ; but the two forms are not only
specifically, but completely generically distinct. Mr. Lucas Barrett was able to examine
the animal alive, and states that " the oral arms are so fixed to the calcareous skeleton
as to be incapable of motion, except at their spiral terminations It has been sup-
posed that these conjoined spiral ends can be unrolled like the proboscis of a butterfly ;
I never saw any disposition of the kind manifested. This species is more lively than
caput-serpentis, moving often on its pedicle, and is more easily alarmed." The cirri are
not protruded beyond the margins of tlie valve ; when the shell is closed they are
bent up ; no currents were detected by Barrett, though frequently sought for. Dr. Gwyn
-leff'reys states likewise {op. cit. vol. v. p. 163) that he has also frequently observed
W. cranium turn round its peduncle, apparently in order to improve its position for the
purpose of feeding, and that the valves on being touched close with a snap.

In Van Bemmelen's " Over den Bouw der Schelpen van Brachiopoden en Chi-
tonen," 1882, and in his " Untersuchungen fiber den anatomischen und histolugischen
Bau der Brachiopoda Testicardinia," 1883, the author enters upon many anatomical and
structural details with respect to Waldheimia cranium^ ; he says that the number of caeca
on the same part of the shell-structure in very old and young specimens was found to
he the same ; this fact, showing that the distance betw^een two caeca (perforations)
does not change with age, led him to the conclusion that no i?itussusception
occurs diiring the growth of the shell. The bases of the calcareous prisms were found
to be very regular-shaped at the margin of the shell (especially in Terehratiila and
Terebratulina sept entriona lis) ; they became very irregular towards the older parts.
The concentric lines of growth occurring on the outer surface were totally absent on the
inner surface, which is explained by supposing the apposition at the margin to stop
for some time, while the formation of new layers on the whole under surface continued.
In Waldheimia cranium he found the sexes were separate.

Mr. Albany Hancock describes and figui-es the soft parts of the animal in his admira-
ble memoir already so often referred to, and from which I now give a few extracts, with
reproductions of his admirable figures of the dorsal and ventral views of Waldheimia

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 65

cranium (PI. XIII. figs. 1, 2). lie says that in Waldhehnia cranium, and in TerebratuUna
caput-seryentis, "the dorsal adjuster muscles are not attached to a hinge-plate, as in
W. australis, but have their insertions in the ventral valve itself, and are very large and
powerful. In both species the superior extremities of these muscles are seen at the
surface of the animal, on each side of the median line, elongated in the antero-posterior
direction and extending between the occlusors almost as far forward as the anterior
margins. . . . The divaricators and the accessory divaricators in W. cranium are likewise
united in the same manner as in the species before alluded to." Mr. Hancock further
observes that " the arms in W. cranium and T. caput-serpentis are disposed in the same
manner as in W. australis ; and in the former the calcareous loop is precisely similar to
that of the latter ; but in T. caput-serpentis it is very much reduced, the extended lateral
portions having almost entirely disappeared, little more than the transverse portion
existing ; and this, together with the crural processes, which are united below across the
median line, forms a collar upon which the bases of the arms rest.

" In W. cranium the intestine is very short, terminating in a blind sac before it
reaches the ventral wall of the perivisceral chamber. It tapers gradually to a point,
which is rounded, and suspended in its place by the mesentery. The mucous membrane,
lining the intestinal tube of If. cranium, is exceedingly thick, and produced into five
or six excessively stout, longitudinal folds, which in transverse sections exhibit a pyra-
midal contour, their apices almost meeting in the centre of the tube .... In W. cranium
the genitalia are arranged as in W. australis, only the bands do not extend so far
forward, and are of a pale yellow colour. The red matter is also present, sprinkling the
surface with distant round spots. The bands arc very finely granular, and in no instance
have I detected eggs in them. It is therefore probable that those examined were out
of season." Mr. Ilancock also observes: — "There is no modification to note in the
perivisceral chamber in any of the Terebratulidaj that I have had an opportunity of
examining. The pallial sinuses, however, vary in several species. Thus in W. cranium,
though there are still four such sinuses in each lobe, the trunks are proportionately
smaller, and more nearly of a size ; the branches are fewer and more attenuated, but, as
in the other species, divided dichotomously twice or thrice, without any very marked
symmetry."

The animal of Waldheimia cranium although differing in some unimportant details
from that of Waldheimia flavescens is essentially similar. In both the loop is the same,
and there is no difference, of any great importance, in the shape of the shell. I therefore
question the necessity of bm'dening the nomenclature by placing W. cranium and
IF. Jiavescens in difi'erent and distinct genera. But as the contrary view has been
expressed by such excellent observers as Prof. W. King, Douville, Zittcl, Waagen,
Deslongchamps, and others, I would not wish to press my own views too far, in
opposition to theirs. M. DouvUle seems to think that W. cranium possesses a special
development of its loop ; while M. E. Deslongchamps, at page 1-il of his Etudes
critiques sur les Brachiopodes,' 1881-, difiers from M. Douville, and expresses his opinion
that the general appearance of the loop of Macandrcvia cranium is actually the same as
that attributed to JFaldheimia. The shape of the principal stems show s the greatest

SECOND SEUIES.— ZOOLOGY, VOL. IV. U

66 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

resemblance to those of Zeilleria ; but the position of the larger-sized adductor muscles
is no longer the same as in Waldhelmia, while the complete absence of a mesial septum
and the shape of the largely divided hinge-plate wovild, in his opinion (Deslongchamps'),
be valid grounds for separating the genus Macandrevia from Waldhelmia.

35. Waldheimia (Macandrevia) tenera, Jeffreys, sp. (Plate XII. figs. 6-10.)

Terebratula tenera, Jeffreys, Ann. & Mag. Nat. Hist. 4th ser. vol. xviii. p. 250, 1876, and Proc.
Zool. Soc. 1878, p. 405, pi. xxii. fig. 7.

Shell rather small, extremely thin and delicate, oval, longer than wide, rounded
laterally, less so in front ; surface smooth, marked only by fine concentric lines of
growth, and perforated by minute canals. In the interior of the dorsal valve po cardinal
process is observable ; hinge-plate comparatively large, and divided into two parts by a
narrow mesial depression, between which, in the middle, a very narrow delicate longi-
tudinal ridge or rudimentary septum is present, which extends to about one fifth of
the length of the valve. The inner slopes of the hinge-plate extend likewise in the
shape of two septa of small elevation to about the same distance, first diverging, then
converging to the anterior extremity of the small median ridge. At the base of the
hinge-plate the principal delicate stems of the loop are attached, and these extend to
about two thirds of the length of the valve before they are reflected. Colour light
brown. Length 6, breadth 4, depth 3 lines.

Hab. Dredged by Dr. Gwyn Jeffreys during the return voyage of H.M.S. ' Valorous '
from Davis Strait, in lat. 56" 11' N., long. 37° 41' W., at a depth of 1450 fathoms,
on a sea-bottom of Globlf/erlna-ooze and stones.

Obs. I have seen two or three perfect examples of this extremely delicate species,
brought home by Dr. Gwyn Jeffreys. The shell seemed full-grown. A specimen about
one line in length showed traces of one of its early stages of growth, in the presence of a
small vertical septum, at about half the length of the valve, to which the loop at that age
had an attachment, as Friele has so well described to be the case in Waldheimia cranium.

Dr. Gwyn Jeffreys observes that " this species differs from T. cranium in being only half
the size in exact measurement, and consequently one fourth in bvilk ; it is of a different
shape, texture, and colour, compressed instead of convex, having a much shorter beak
and smaller orifice, with not half the proportionate number of tubei'cles ; and the blades
are closer together, and do not extend so far towards the front. In the young of each
species the comparative number of tubercles and prominence of the beak are distinctly
marked ; and the septum in the present species is shorter, although conspicuous and
gnomon-shaped."

Uncertain Species.

36. Waldheimia Wyvillii, Davidson. (Plate X. figs. 5, 6.)

Waldheimia Wyvilli, Davidson, Proc. Roy. Soc. vol. xxvii. p. 438, 1878; and {W. tvyvillii) Report
on the Bracliiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 44, pi. iii. figs. 13 a, b, 1880.

Shell ovate or longitudinally oval, very thin, semitransparent, light brownish yellow,
smooth, marked at intervals by concentric lines of growth. Dorsal valve moderately

DE. T. DAVIDSON OX EECENT BEACIIIOPODA. 67

convex longitudinally, slig-litly flattened along the middle. Ventral valve deeper and
more convex than the dorsal one, without sinus ; beak incurved, truncated by an
incomplete foramen, margined laterally by small deltidial plates. In the interior of the
dorsal valve the loop is long and simple, the principal branches extending to a little
beyond two thii'ds of their length before becoming reflected. Length 9, width 7, depth
5 lines.

Hah. Only one incomplete example was dredged by the 'Challenger' Expedition, off
Valparaiso, at a depth of 21C0 fathoms. Terchratida Wi/vlllii and Discinisca atlantica
were obtained at the same time.

Ohs. In external shape this species approaches Waldheimia cranium, which is, however,
a thicker and more convex shell. The extremely delicate shell of W. Wyvtllil is very
remarkable, and reminds us of that of W. tenera, from which, however, it seems to
differ in size and in some other particulars.

The fact that several of the species obtained at such depths as Terehralula Wyv'dlii
and Discinisca atlantica possess such extremely thin and delicate glass-like shells, is
certainly worthy of notice.

Note. — In accordance with the verbally expressed wishes of the late Thomas Davidson, LL.D.,
F.R.S., " The Davidson Collections of Recent and Fossil Brachiopoda" were presented to the nation,
with the manuscripts and original drawings for many of his publications on the Brachiopoda, and the
extensive sci-ics of works and pamphlets he had accumulated during nearly fifty years' investigation of
this group of animals. The recent specimens are associated with the fossil species in the Geological
Department of the Natural History Branch of the British Museum at South Kensington. The literature
now forms part of the libraiy of the same department in that Institution. [A. C]

DESCRIPTION OE THE PLATES.
Plate I.

Figs. 1-6. Liothyris vilrea, Born, sp., at various stages of growth. Mediterranean Sea (Davidson
Collection, Geological Department, British jNIuscum). G. Interior of the dorsal valve,
enlarged, cp, cardinal process ; si, short loop ; clg, diverging grooves for the attachment of the
pallial sinuses.

Fig. 7. Exterior of ventral valve of the same species, showing the four internal radiating furrows which
serve for the attachment of the pallial sinuses, seen tlirough the transparent shell.

Fig. 8. Interior of the ventral valve after E. Ueslongchamps. cv, visceral cavity ; ap, raised portion of the
mantle forming the walls of the visceral cavity ; svl, furrow corresponding to the lateral
venous sinus ; svm, furrow corresponding to the median venous sinus.

Fig. 9. Interior of the ventral valve showing the position of the muscular impressions, a, adductor
or occlusor ; b, ventral adjustors ; c, divaricators.

Fig. 10. Malformation of Liothyris viirea (after E. Deslongchamps) , seen in profile, showing a longitu-
dinal frontal septum in both valves.

Fig. 11. Full-grown spieulum, much magnified (after E. Deslongchamps), from a venous sinus near the
raised part of the mautle oi Liothyris vitrea.

Fig. 12. Portion of the shell of Liothyris vitrea, magnified (after Van Bemmclcu), to show the perforations
and imbricated arrangement of the prisms.

9*

68 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Figs. 13-13 b. Liothyris vifrea, var. minor, Philippi, from the Straits of Messina (Davidson Collection,

Geol. Dept., British Museum).
Figs. 14-16. Liothyris vitrea, var. Davidsoni, A. Adams, from Satanomosaki, Japan. 14. (Davidson

Collection, Geol. Dept., British Museum.) 16. Interior of dorsal valve.
Figs. 17, 18. Liothyris arctica, Friele, sp. 17. Exterior, of natural size. 18. Interior of dorsal valve,

enlarged. (Davidson Collection, Geol. Dept., British Museum.)
Fig. 19. Liothyris cernica, Crosse, sp. : after Crosse's figure, Jouru. de Couch, vol. xvi. pi. i. fig. 3. The

specimen was obtained near the Island of Mauritius, from the stomach of a fish.
Figs. 20, 21. Liothyris Bartletti, Dall, sp., from near Santa Cruz (Museum of Comp. Zool., Harvard).

Plate II.

Figs. 1-4. Liothyris Moseleyi, Davidson. \-lb. Exterior of the shell. 2. Interior of dorsal valve, to
show the loop. 3. Interior of ventral valve, enlarged, showing the muscles ; a, occlusor j
b, ventral adjustor ; c, divaricator ; m, mantle ; n, dorsal pallial nerves ; d, dorsal pallial arteries.

4. Interior of dorsal valve, showing the labial appendages. ' Challenger ' Expedition. West
of Kei-guelen Island. (Zoological Department, British Museum.)

Figs. 5-7. Liothyris uva, Broderip, sp. 5-5 b. Type from Gulf of Tehuantapec (Zoological Department,
British Museum). 6-6 6. A smaller specimen, from the same locality (Davidson Collection,
Geol. Dept., British Museum). 7. Interior of dorsal valve, to show the loop.

Figs. 8-14. Liothyris WyviUii, Davidson, at various stages of growth. 12. Interior of dorsal valve, to
show the loop. Dredged by ' Challenger ' Expedition at different places named in the description
of species. (British Museum and Davidson Collection.)

Figs. 15, 16. Liothyris subquadrata, Jeffreys, sp. 15, 15 a, 15 6. Exterior of the shell after the type, in
Davidson Collection, Geol. Dept., British Museum; 15c. Shell-sculpture enlarged. FromSetubal,
coast of Portugal, near the mouth of the Tagus. 16. Interior of dorsal valve of the same species.

Figs. 17, 18. Liothyris sphenoidea, Philippi, sp. : ' Travailleur ' Expedition; off Morocco. (Museum
d'Histoire Naturelle, Paris.) 18. Interior of dorsal valve, to show the loop.

Figs. 19-22. Liothyris sphenoidea, Philippi { — cubensis, Pourtales). 19, 19 a, 19 6, 21, 22. Florida reefs,
dredged by M. de Pourtales (Davidson Collection, Geol. Dept., British Museum). 20. Ascension
Island; dredged by 'Challenger' Expedition (Zoological Departmeut, British Museum).

Figs. 23-23 6. Terebratula (or Terebratulina ?) Dalli, Davidson. 23. Type, natural size : dredged by
'Challenger' Expedition, lat. 34° 37' N., long. 140° 32' E. 23 a, 23 6. Enlarged. The only
known specimen is in the Zoological Department, British Museum.

Plate III.

Figs. 1-3 fl. Terebratulina WyviUii, Davidson. 1, 1 a, 1 6. Exterior of the type, dredged by 'Challenger'
Expedition, N.W. of St. Thomas, West Indies, in 390 fathoms. 2. Interior of dorsal valve from
same species (Zool. Dept., British Museum). 3. Smaller specimen dredged by the ' Travailleur '
Expedition, from the western coast of Africa (Museum d'Histoire Naturelle, Paris). 3 a. Shell-
sculpture enlarged.

Figs. 4-5 a. Terebratulina Crossii, Davidson. 4,4 a. Type from Japanese water (Coll. of M. H. Crosse).

5, 5a. A smaller specimen, same habitat (Davidson Collection, Geol. Dept., British Museum).
Fig. 6. Tei-ebratulina Crossii, Davidson. A large light salmon-coloured specimen obtained from Sagami

Bay, Japan, by Dr. L. Doderlein, and from his Collection.
Figs. 7-11 a. Terebratulina japonica, G. B. Sowerby, sp. A series of specimens from Japanese waters

(British Museum and Davidson Collection) . 11,11a, represent the Terebratula angusta, Adams

and Reeves, which is only a young Terebratulina japonica.
Figs. 12, 12 a. Terebratulina caput-serpentis, Linne, sp., from Sagami Bay, Japan, found associated with

T. japonica. In the Collection of Dr. DiJderlein.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 69

Plate IV.

Figs. 1-5. Various stages of growth of Terebratidina caput-serpentis, Liniie, sp. 1, 2. Large specimens
in the Zool. Dcpt., British Museum. 3, 4, 4«, 4 b. Specimens of ordinary size from the coast
of Scotland. 5. A very young specimen (after E. Deslongchamps).

Fig. 6. A young specimen in which the crura of the loop are not yet united.

Fig. 7. Interior of the dorsal valve of TerebratuUna caput-serpentis (after E. Deslongchamps), showing
the labial appendages and the cirri, ac, cardinal process ; vc, visceral cavity ; b, mouth ; be,
descending or primary portions of the arms ; br, ascending or reflected portions of the arms ;
mi, interhranchial membrane ; e, shield ; sp, median poi'tion of the arms spirally coiled.

Fig. 8. Dorsal view of Terebratidina caput-serpentis deprived of its shell (after Hancock), n, pallial
lobe ; b, body ; c, peduncle ; d, d, great pallial or genital sinuses ; e, ramifications of ditto ;
/, muscular ties passing between the walls of ditto ; ij, genitalia seen through the walls of
ditto ; h, marginal fold ; i, setae ; j, extreme pallial margin ; k, depressions corresponding to
the bases of the crura ; /, ridge formed by the union of the pallial margins ; m, edge of dorsal
mesentery; n, liver seen through the walls of the perivisceral chamber; o, extremities of
anterior occlusors ; p, ditto of posterior occlusors ; q, ditto of divaricators ; r, ditto of dorsal
adjusters.

Fig. 9. Ventral view of the same (after Hancock) ; the letters up to j agree with those of fig. 8. k, ex-
tremities of occlusor muscles ; /, ditto of divaricators ; m, ditto of ventral adjusters j n, ditto
of peduncular muscle ; o, peduncular nerves.

Fig. 10. Interior of the ventral valve of T. caput-seipentis (after E. Deslongchamps), showing the mantle
in its entirety, vc, visceral cavity ; ap, raised portion of the mantle forming the wall of
the visceral cavity ; o, organs of reproduction ; svl, lateral venous siniises ; svl*, trunks
accruing from the division of the sinuses ; svm, median venoiis sinus ; r, small branches of the
venous sinuses ; on all the circumference one sees distinctly the festooned muscular border of
the mantle, whereon arc implanted a multitude of hairs (enlarged 5 diameters) .

Fig. 11. Interior of the dorsal valve of the same species (after E. Deslongchamps), showing the mantle
also in its entirety. The same letters indicate the same jiarts on this valve, and the parts cor-
respond with those of the ventral valve, with the excejition of ab, which shows the brachial
apparatus in the shape of a ring (enlarged 5 diametez's).

Plate V.

Figs. 1-30. TerebratuUna septentrionalis, Couthouy, after Morse, "Embryology of TerebratuUna," Mem.
Soc. Boston Nat. Hist. vol. ii. pi. viii., 1873. — 1. Acluster of eggs from the genital band. 2,3,4.
Eggs from the perivisceral cavity immediately after their escape from the pallial sinuses. 5. Firet
ciliated stage. G, 7 , 8. Successive stages of transverse division of embryo, showing long tuft of
cilia at cephalic extremity. 9, 10, 11. From a single embryo, showing various outlines assumed
while swimming. 12, 13, 14. Different embryos showing first appearance of caudal or pedun-
cular segment. 15, 16. Representing the same embryo contracted and expanded. 17, 18, 19.
Embryos just attaching themselves by their caudal segment. 20. Embiyo showing first appear-
ance of ventral (?) area by the bulging of the thoracic ring. 21, 22. Embryos in various
stages showing widening of thoracic ring, and its gradual growth towards enclosing the
cephalic ring. 23, 24, 25. Successive stages of the embryo, showing formation of dorsal and
ventral areas by the folding and growth of the thoracic ring. In fig. 26 the head is still seen
projecting from the dorsal and ventral folds of the thoracic ring. 27 to 30. Succeeding stages
of embryos drawn in various positions. The deciduous setae appear in these stages.

Fig. 31. One of the earliest stages of TerebratuUna septentrionalis, after Morse {op. cit. pi. i. fig. 3),
" in which the body has rapidly lengthened, and the peduncle is equal in length to the

70 DH. T. DAVIDSON ON RECENT BEACHIOPODA.

remaining portion of the animal." p, peduncle; ^ja, point of attachment of peduncle; c<b,

pallial cfeca ; se, setae. (" Early Stages of TerebratuUna," Mem. Soc. Boston Nat. Hist. vol. ii.

pi. i. fig. 3.)
Fig. 32. A spiculum of TerebratuUna caput-serpentis : highly magnified (after Hancock) .
Fig. 33. Portion of the internal surface of the shell of T. cajjut-serpentis , showing the imbricated

arrangement, and the intei'nal orifices of the vertical perforations arranged in rows : magnified

100 diameters (after Carpenter).
Figs. 34, 34 a. TerebratuUna caput-serpentis : very young, dredged by the ' Travailleiir ' Expedition. Coll.

of the Marquis de Folin.
Figs. 35-37. TerebratuUna caput-serpentis, var. emargmata, Eisso, = var. mediteiTanea, Jeffreys; from

the Mediterranean Sea; 37, was dredged alive between Pantellai'ia and Sciacca, Sicily. All

in Davidson Collection, Geol. Dept., British Museum.
Figs. 38-40. TerebratuUna caput-serpentis, var. unguicitlata, Carpenter : 38, 39, exterior of shell ;

40, interior of dorsal valve. Off Vancouver Island. (Davidson Collection, Geol. Dept.,

British Museum.)
Figs. 41-42 a. TerebratuUna CaiUeti, Cross e. 41-41 c. From Barbados (Davidson Collection, Geol.

Dept., British Museum) ; 42, 42 a. Type, after Ci-osse's figure.
Figs. 43-52. TerebratuUna septentrionaUs, Couthouy, from off Halifax, Nova Scotia, and Lockport,

Maine, at different ages (Davidson Collection, Geol. Dept., British Museum). 43, 44. Full-
grown individuals. 47. A cluster of specimens attached to one another. 50, 51. Young

examples. 48. Interior of dorsal valve and loop; 49. Dorsal valve, showing labial appendages.

52. Portion of shell, magnified.
Figs. 53-53 b. TerebratuUna Cumingi, Davidson : type. From China seas.
Fig. 54. TerebratuUna abyssicola, Adams and Reeve, sp. : after Reeve's figure. OfE Cape of Good Hope.

(Davidson Collection, Geol. Dept., British Museum.)

Plate VI.

Figs. 1-8 b. TerebratuUna canceUata, Koch, sp. 1-7. Specimens dredged by the ' Challenger ' Expe-
dition off Moncoeur Island, Bass Strait, in from 38 to 40 fathoms ; 7. Interior of the dorsal
valve, enlarged, showing the labial appendages. 8-8 b. A small dwarfed form, dredged by
Mr. J. Brazier at Inner North Head, Port Jackson, N.S.W. (Davidson Collection, Geol. Dept.,
British Museum.) Specimens 1-7 in Zool. Dept., British Museum.

Figs. 9-14. TerebratuUna radiata. Reeve, sp. Different forms from the Cape of Good Hope (Davidson
Collection, Geol. Dept., British Museum). 12. Specimen showing black colour-markings.

Figs. 15-17. TerebratuUna t Murrayi, Davidson. 15. Outline of shell, natural size. 15 a,b, enlarged.
16. Dorsal valve, with loop magnified. 17. Dorsal valve, showing mantle, enlarged. Dredged
by the ' Challenger ' Expedition near Kermadec Island, south of the Fiji Islands, depth 600
fathoms. (Zool. Dept., British Museum.)

Figs. 18-20. TerebratuUna ? tuberata, Jeffreys, sp. From Josephine Bank, 340 to 430 fathoms (Collection
of Dr. Gwyn Jeffreys, now in the Smithsonian Institution, Washington, U.S.A.: figures all
much enlarged. 19. Interior of the dorsal valve.

Figs. 21, 22. TerebratuUna ? trigona, Jeffreys, sp. A young and immature shell, dredged by Mr. Saville
Kent off the coast of Portugal, at a depth of 501) fathoms (Coll. of Dr. Gwyn Jeffreys, Smith-
sonian Institution, Washington, U.S.A.). 22. The shell opened, to show the loop.

Figs. 23-25 ft. Terebi-atuUna? incerta,Da.\'idson. 23, 24«. Dredged by the ' Challenger ' Expedition in
lat. 1° 47' N., long. 24° 26' W. (Zool. Dept., British Museum, and Davidson Collection).
25, 25 a. Interior of dorsal valve, with loop, after Dall, magnified 2i diameters ; dredged by
the ' Blake' Expedition off Bequea. (Smithsonian Institution, Washington, U.S.A.)

DE. T. DAVIDSON ON EECENT BEACIIIOPODA. 71

Plate VII.

Fig. 1. TerebratuUna [Agulhasia) Davidsuni, King: natural size. 1 a, 1 b, 1 f. Shell enlarged.

Fig. 2. Ditto, interior of ventral valve, enlarged.

Figs. 3, 4. Ditto, interior of dorsal valve and sectional diagram of same, enlarged.

Fig. 5. Tubuli cliaracteristic of TerebratuUna caput-sei-pentis {1-d after King). (Davidson Collection,
Gcol. Dept., British ISIuseum.)

Figs. 6-lt. Waldheimia flavescens, Lamarck, s]). ( = Terebratula australis, Quoy). Different specimens from
Port Jackson, N.S.W., showing modifications in shape and in ribbing. 10, (afterG. B. Sowerby),
shows the extent the animal opens its valves. 13, represents the var. recurva, Quoy, ft-om Shark
Point, Port Jackson. 12, 12 a. A young smooth shell, from Bottle and Glass Rocks, Port Jack-
son. All the specimens, with the exception of fig. 10, from the Davidson Collection, Geol.
Dcpt., British Museum.

Fig. 15. Dorsal view of IValdhebnla flavescens, the .shell having been removed (after Hancock) . «, pallial
lobe ; b, body ; c, peduncle ; d, great inner pallial sinuses, giving off branches to the margin ;
e, outer ditto ; /, genitalia seen through the pallial membrane ; g, red matter of ditto ; /;, mar-
ginal fold ; i, seta; ; j, eircumpallial vessel ; k, extreme pallial margin ; /, median fissure, corre-
sponding to longitudinal plate in valve ; m, depression occasioned by the hinge-plate and the
bases of the crura ; n, orifices for the passage of the crura ; o, ridge formed by the union of the
pallial margins ; p, extremities of anterior occlusors ; rj, ditto of posterior occlnsors ; r, ditto of
divaricators ; s, ditto of dorsal adjustors ; t, liver seen through the wall of the body.

Fig. 16. Ventral view of the same; the letters up to and including k correspond to those of fig. 15.
/, extremities of the occlusor muscles ; m, ditto of divaricators ; n, ditto of accessory divaricators ;
0, ditto of ventral adjustors; ;;, ditto of peduncular muscles; g, cjecal extremity of intestine,
seen through the wall of the perivisceral chamber ; r, peduncular nerves.

Fig. 17. Thin lamella of shell of Waldheimia flavescens (after Carpenter), showing the parallel disposition
of the flattened prisms, and the regular arrangement of the passages which intervene between
them ; and at a the outcrop of these prisms of the internal surface of the shell. Magnified
100 diameters.

Fig. 18. Internal surface of Waldheimia flavescens (after Carpenter), showing the imbricated arrangement
of the extremities of the prisms, which are seen longitudinally at a. Magnified 100 diameters.

Fig. 19. External surface of shell of Waldheimia flavescens (after Carpenter), showing the large trumpet-
shaped ends of the vertical passages, covered in by opercular disks, which have radiating lines
proceeding from them. Magnified 100 diameters.

Note. — Figures of the dorsal and ventral valves, of the muscular system, and of the labial
appendages and animal of W. flavescens are given in the text at pp. 42, 45, 47, and 48 (woodcuts,
figs. 3, 4, 5, G, 7, & 8).

Plate VIII.

Fig. 1. /r«W/(t'm/a wwo*«, Solandcr, sp. Type. (See Dixon, ' Voyage round the World,' 1789.) From
Falkland Islands.

Figs. 2-2 c. Waldheimia venosa. The largest specimen known, dredged alive in Stanley Harbour,
Falkland Islands, by Admiral B. J. Sulivan in 5 or 6 fathoms, 1844.

Fig. 3. Widdheimia venosa. Type of the Terebratula globosa of Lamarck, which was badly figured in
the Encyclopedic Methodique, pi. 239. fig. 2, 1789. (Museum d'Histoire Naturelle, Paris.)

Fig. 4. Ditto. Type of the Terebratula physema, Valenciennes, after Reeve's figure, ' ^Monogr. of Tere-
bratula, Conch. Icon.' pi. vi. fig. 23. From Cocpiimbo. (Museum d'Histoire Naturelle, Paris.)

Fig. 5. Ditto. Interior of the dorsal valve of a full-grown specimen, to show the loop.

Fig. G. Ditto. Type of the Terebratula Fontaineana, A. d'Orbigny, ' Voyage dans I'Am^rique Meri-
dionale,' vol. v. pl. 85. figs. 30 & 31, 1847. (Reduced f natural size.) From Coquimbo.

72 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Plate IX.

Figs. 1, 1 a. Waldheimia venosa, var. dilatata, Lamarck. Type of Lamarck's Terebratula dilatata, from
a drawing made in Paris from the type in the Museum d'Histoire Naturelle, Paris.

J'igs. 2-'13. Waldheimia lenticuluris, Deshayes, sp. A series of specimens of different forms and ages from
the Straits of Fouveau, New Zealand, in 15 fathoms water (Davidson Collection^ Geol. Dept.,
British Museum). 2-3 b. Large specimens. 10. Interior of dorsal valve, showing loop in the
adult condition. 11-13 a. Modifications assumed by the loop previous to its attaining the
adult state.

Plate X.

Figs. 1-4. Waldheimia Grayi, Davidson. 1, 1 a, 2. Typical form. 3. Interior of dorsal valve, to show the

loop. 4j 4 a, 4 b. Variety transversa. All dredged from Japanese waters except the specimen

shown in fig. 2, which was dredged by Sir E. Belcher in the Straits of Corea. (Davidson

Collection, Geol. Dept., British Museum. )
Figs. 5, 6. Waldheimia Wyvillii, Davidson. 5, 5 a. Exterior of shell. 6. Interior of dorsal valve,

enlarged, showing the loop. Dredged by 'Challenger' Expedition, lat. 33° 31' S., long.

74° 43' W., depth 21G0 fathoms. (Zool. Dept., British Museum.)
Figs. 7-17. Waldheimia kerffuelenensis, DnYidson. 7-15. A series of forms of different ages. 16. Interior

of dorsal valve, showing the loop. 17. Interior of dorsal valve, showing the labial appendages.

All dredged by the ' Challenger ' Expedition south of Kerguelen Islands, also off Marion Islands.

Found in depths varying from 100 to 150 fathoms. AU the specimens figured are in the Zool.

Dept., British Museum.

Plate XI.

Figs. 1-10. Waldheimia septigera, Loveii,sT^. 1-1 c. From Faeroe Sound, 570 fathoms (Davidson Collec-
tion, Geol. Dept., British Museum) . 2-2 b. A very large broad specimen, after Sars. 3. A young
example, from the British sea, between Shetland and Faeroe (' Porcupine ' Expedition), depth 345
fathoms. 4. Interior of dorsal valve with its fully developed loop. 5. Profile view of the same
(after Sars). 6. View of the loop seen from the front, much enlarged. 7-10. Different stages in
the development of the loop, after H . Friele, figures magnified ; all from Norwegian waters.

Figs. 11-13. Waldheimia Kaphaelis, Dall. 11-11 e. A very perfect example from off the coast near
Jeddo, Japan (Davidson Collection, Geol. Dept., British Museum). 12, 12a. A large typical
example from Sagami Bay, coll. Dr. Doderlcin. 13. Interior of dorsal valve, showing its fully
developed loop. 12-13. In the Museum of the Smithsonian Institution, Washington, U.S.A.

Plate XII.

Figs. 1-5. Waldheimia floridana, Pourtales, at different ages, dredged by Agassiz and de Pourtales off
Florida reefs, between 100 and 200 fathoms (Davidson Collection, Geol. Dept., British
Museum). 5. Interior of dorsal valve, to show the loop.

Figs. 6-10. Waldheimia {or Macandrevia) /t'Me?-«, Jefireys, sp. 6-6 b. Specimen of the natural size. 7. In-
terior of ventral valve, enlarged. 8. Interior of dorsal valve, to show the loop. 9. Posterior portion
of the interior of the dorsal valve very much enlarged, to show the hinge-plate and septa. 10. A
very young example in which a small pillar-shaped ventral septum is seen in the interior of the
dorsal valve. These figures, drawn by Davidson, were published by Jeffreys in the Proc. Zool.
Soc. for 1878. Dredged by Dr. Gwyn Jeffreys, lat. 56° 11' N., long. 37° 41' W., 'Valorous'
Exjjedition, at a dejjth of 1450 fath. (Jeffreys Collection, Smithsonian Institution, Washington,
U.S.A.)

Dli. T. DAVIDSON ON RECENT BKACIIIOPODA. 73

Fifi;s. 11-23. IVuhlheimia (or Macandrevia) craftiww, Miillcr, sp. \\-\^ b. A series of dift'ercut ages.
11. A very large example (after Sars). 15-15 b. A very minute or first stage (after Friele).
10. Tlic first stage of the development of the loops with a coherent apopliysis (Friele).

17, 17a. Sijccimen a little further advanced: a, lamellae; b, vertical walls; c, tube (Friele).

18, 18 ff. Opening of the posterior end of the tube (Friele). 19. Perforation of the lateral
walls (Friele). 20, 21. Connection with the septum is broken (Friele). 22. The lamel-
processes separated. 23. Adult and fully developed loop. All the specimens from Norwe-
gian waters. (See Friele, Develop. Skelet. in Jl^alr/heimia, Archiv Math, og Naturviden-
skab, ii. p. 380, pis. i. & ii., 1877.)

Plate XIII.

Fig. 1. IVuldhelmia {ov Macandrevin) cranium, Miiller, sp. Dorsal view of the animal, much enlarged
(after Hancock), o, pallial lobe ; Zi, body; c, peduncle; d, great inner pallial sinus; e, outer
ditto ; /, genitalia appearing through the walls of the sinuses ; y, marginal fold ; h, setae ; i,
cireumpallial vessel ; _;', extreme pallial mai-gin ; k, two lobes corresponding to cavities at the
sides of the foramen ; /, similar lobes corresponding to the cavities in the umbonal region of
dorsal valve ; m, ridge resulting from the union of the pallial margins ; n, extremity of anterior
occlusoi's ; 0, ditto of posterior ocelusors ; p, ditto of dorsal adjustors ; q, ditto of divaricators.

Fig. 2. Ventral view of the same (after Hancock). The letters up to k as in fig. 1 : — I, extremities
of the occlusor muscles ; m, ditto of divai'icators ; ni*, portions of ditto, corresponding to
the accessory divaricators ; n, ditto of ventral adjustors ; o, ditto of peduncular muscle ;
p, peduncular nerves.

P'igs. 3-9 ff. Terebratella coreanica, Adams and Reeve, sp. 3. Type specimen figured by Reeve. 4-4 c. A
fine and large specimen. 5, 5 a. A still larger example {Terebratula miniata, Gould), dredged
by L. V. Schrenk, from Hakodadi, Japan. G, Ga. An elongate globose variety, dredged by Capt.
St. John in Tsuga Strait. 7. Interior of dorsal valve, to show loop. 8, 8 b. Elongate variety
(7". 2?o(/c//a;-</«, Davidson) . 9, 9«. Var. Bo«cAo«/i, Davidson. Specimens 4, 5, fi, 7, and 8, in
the Davidson Collection, Geol. Dept., British Museum ; 9, in the Zool. Dcpt., British
Museum.

SECOND SERIES. — ZOOLOGV. VOL. IV. ]()

[ 75 ]

II. A Monograph of Hecent BracMopoda.—Vavt II.
i?y Thomas Davidson, LL.D., F.ll.S., F.L.S., F.G.S., §-c.

Read 3rd June, 1886.

(Plates XIV.-XXV.)
Subfamily Tekebeatellin^.

Genus TEEEBEATELLA, d'Orbigny, 1847.

In this genus Alcide d'Orbigny proposed to include all those species in which the long
reflected loop has its principal stems twice attached : — first by their crura to the base of
the hinge-plate, and again by horizontal laminae given off from about the middle of the
principal stems, which afterwards become attached to the anterior extremity of a low
mesial septum. The Terebratula dorsata of Gmelin was selected as the type.

In 1870 Mr. Dall proposed to separate from Terebratella, as thus defined, those forms in
which the reflected portions united form a loop, and in which the mesial septum is very
large, elevated, and projects beyond the anterior extremities of the loop. Ty^pe Mar/asella
Jiexiiosa, P. King.

It has been ascertained that great changes take place in the form of the loop of Tere
bratella during the progress of its development from the young to the adult condition
and that when young, and up to a certain age, it shows the loop and septum of Magasella
Indeed Mr. Dall has frankly admitted to me that some of the species referred to Maga
sella are immature forms of Terebratella ; but for some others, such as Magasella flexuosa,
P. King, Magasella siiffusa. Peeve, which retain the Magasella loop and septum in their
adult condition, he proposes to retain the subgenus Magasella.

We have recognized nine species of Terebratella and three uncertain ones, viz. : —

1. Terebrntella dorsata, Gmelin.

2. transversa, Vt. B. Sowerby.

G. Terebratella rubicunda, G. B. Sowerby.

7. frontalis, MiddendoriF.

8. cruenta, Dillwyn.

9. Marue, Adams.

3. corcanira, Adams & Reeve.

4. liluiifordi, Diiiikcr.

5. spUzbergensis, Davidson.

The uncertain species are Terebratella putvinata, Gould ; Terebratella rubiginosa, Dall , Terebratella
Frielii, Davidson.

The very numerous synonyms have been added to the descriptions of the species.
37. Terebratella dorsata, Gmelin, sp. (Plate XIV. figs. 9-19.)

Anomie Magellanique striee, Davila, Catalogue Systematiciue dcs Curiosites dc la Nature, vol. i. p. 312,
pi. XX. fig. A, 17G7.

? magellanique, Walchs, Naturforseher, p. 202, pi. iii. figs. 3, 4, 1774.

? magellanique, Favanne de Monteervcllc, Conebyliologie, pi. xli. fig. A. 3, 1780.

SECOND SERIES. — ZOOLOGY, VOL. IV. 11

76 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Anomia striata Mayellanica, Chemnitz, Neues syst. Coocli. -Cabinet, vol. viii. p. 101, tab. 78. figs. 710,
711, 1785.

Terebratula dorsata, Gmelin, ed. Linne's Syst. Nat. vol. iv. p. 3348, 1788; Bruguiere, Encycl. Meth.
pi. 242. fig. 1, 1789 ; Lamarck, An. sans Vert. vol. vii. p. 246, 1819 ; G. B. Sowerby, A Catalogue of Shells
of the late Earl of Tankerville, p. 28, 1825.

Terebratula bilohata, Blainville, Diet. Sci. Nat. vol. liii. p. 166, 1828 (refers for fig. to Encycl. Meth.
pi. 242. fig. 1).

Delthijris dorsata, Menke, Synopsis Methodica Molluscorum, 2nd ed. p. 96, 1830.

Terebratula chilensis, Broderip, Trans. Zool. Soc. vol. i. p. 141, pi. 22. fig. 1, 1833 ; Owen, On the
Anatomy of the Brachiopoda, Trans. Zool. Soc. vol. i. p. 146, pi. xxii. figs. 3-11, 1833.

Terebratula Sowerbii, Owen, Ou the Anatomy of the Brachiopoda, Trans. Zool. Soc. vol. i. p. 149,
pi. xxii. figs. 15, 16, 1833 ; King, Zool. Journ. vol. v. p. 338, 1835.

Terebratula dorsata, Anton, Verzeichuiss der Conchylien, p. 23, 1839; Kiister, Chemnitz's Conch. -
Cab. vol. vii. p. 23, pi. 1. fig. 17, pi. 2. figs. 14, 15, 1843.

Terebratula lupinus, Philippi, Neuen Conchylien, Archiv fiir Naturgeschichte, Jahrg. xi. Band i. p. 58,
1845.

Terebratula dorsata, King, Ann. & Mag. Nat. Hist. 1st ser. vol. xviii. p. 39, 1846; G. B. Sowerby,
Thes. Conch, p. 346, pi. Ixviii. figs. 15-17, 1846.

Terebratula Chilensis, G. B. Sowerby, Thes. Conch, p. 347, pl. Ixviii. figs. 18, 19, 1846.

Terebratula Soverbii, G. B. Sowerby, Thes. Conch, p. 348, pl. Ixviii. figs. 20-22.

Terebratula dorsata and T. chilensis, A. d'Orbigny, Voyage dans I'Amer. Merid. vol. v. pp. 675, 676,

1847.

Terebratella chilensis, d'Orbigny, Mem. de I'Acad. des Sci. pl. vii. fig. 13, 1847.

Terebratella dorsata and T. Chilensis, Davidson, Sketch of a Class, of Recent Brach., Ann. & Mag.
Nat. Hist. 2nd ser. vol. ix. p. 367, 1852, and Br. Foss. Brach., Pal. Soc. vol. i. Introduction, p. 65, pl. vi.
figs. 11-13, 1853.

Terebratula dorsata, T. Chilensis, and T. Soverbii, Woodward & Gray, Cat. of the Brach. in the Brit.
Mus. pp. 87, 88, 1853.

Terebratula dorsata, S. P. Woodward, A Manual of Mollusca, p. 217, fig. 115, 1856.

Terebratella dorsata, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissenseh.
Wien, Bd. xxxvii. p. 208, 1859.

Terebratula {Terebratella) Mayellanica, Reeve, Conch. Icon, vol.xiii. pl. v. figs. 21, a-d, 1860 ; Ann. &
Mag. Nat. Hist. 3rd ser. vol. vii. p. 176, 1861.

Terebratella dorsata, Dall, Amer. Journ. Conch, vi. p. 116, 1870; Proc. Acad. Nat. Sci. Philadelphia,
p. 184, 1873; Zittel, Handb. der Palaontologie, p. 705, fig. 552, 1880; Davidson, Report on the
Brachiopoda, Voyage of H.M.S. 'Challenger,' Zoology, vol. i. p. 44, pl. iv. fig. 4, 1880.

Shell somewliat transversely oval, wider than long, or of a suborbieular trapezoidal
form, broader posteriorly, tapering anteriorly, vritb a mesial flattened sinus of moderate
breadth and depth, commencing at about one third of the length of the valve and
extending to the front. Ventral valve deeper than the dorsal one, with a moderately broad,
gently convex mesial fold of small elevation, corresponding to the sinus in the opposite
valve ; margin flexuous in front, the fold and sinus projecting a little beyond the curved
lateral margins ; beak moderately produced, incurved, and truncated by a large circular
foramen, very little separated from the hinge-line by a deltidium in two pieces ; beak-
ridges sharply defined, and leaving a flattened space between them and the long obtusely
angular hinge-line. Surface of valves marked n'ith numerous narrow angular ribs,

DE. T. DAVIDSON ON RECENT BEACHIOPODA. 77

increasing in number at various distances from the beak and umbo by the interpolation
of shorter ribs between the longer ones, and crossed at intervals by concentric lines of
growth. Shell-structure punctate. Of a very light yellowish white or ochreous colour.
Length 1 inch 8 lines, breadth 1 inch 10 lines, depth 11 lines.

In the interior of the dorsal valve the cardinal process and hinge-plate are well defined.
The loop is long and doubly attached, first to the hinge-plate, again by horizontal lamintc
given off from the principal branches of the loop to a slightly elevated mesial septum,
previously becoming deflected.

Hab. Straits of Magellan ; Bay of Valparaiso, in depths of from 60 to 90 fathoms
(Cuming) ; Eoyal Sound, Kerguelen Island (' Challenger ' Expedition).

Obs. This fine species has received several denominations, and some considerable dif-
ference of opinion has been expressed as to the name the shell should retain. The first
notices I can find of the shell are those of Davila in 1767, Favart d'Herbigny, Walchs in
1774, Favanne in 1780, and Chemnitz in 1785. These early naturalists had described and
figm-ed the species under the designation of the Magellan striated Anomia ; and as that
name is not binomial, Gmelin, in 1778, named it Terehratula dorsata, and, I believe, the
larger number of malacologists have preferred that designation, although some others
have insisted on retaining the name of Magellanica for the shell, which Gmelin should
have adopted. The names chilensis and Soioerbli are certainly synonyms, and L. Reeve
would likewise add to them the T.flexuosa of P. King. If this view were adopted,
one would have also to include the Terebratula rhombea, Philippi, and, in all probability,
the Terehratula htpinus of the same author ; but as these last-named species have large
Magasella-&\iii.\)eA septa and are adult, it may be better, at any rate provisionally, to locate
them in the subgenus MaQasella. I am the more inclined to adopt this view, as many
specimens of Terebratella dorsata, when compared with others of Magusella flexuosa, of
equal dimensions and age, can be distinguished by the absence of the elevated mesial septa.
Terebratella dorsata varies also somewhat in shape and striation ; young specimens
have their valves quite smooth, and even in some full-grown examples the umbo and beak
remain smooth, the ribbing commencing a little lower down. In 1867 Commodore Acton
dredged in the Straits of Magellan a very large number of specimens of Terebratella
dorsata, from the dimensions of one line in length up to twenty, and on his return kindly
presented me with a series of examples illustrating the different ages of the shell.

When quite young, there exists in the interior of the dorsal valve a large and elevated
mesial plate or septum, from the anterior sides of which the principal stems of the loop
take their second attachment. Over these, but quite separate, are two small anchor-
shaped lamelltE, which are attached to the sloping portion of the septum facing the
hinge-plate. After a time these anchor-shaped lamellae become united, and their lower
edges are connected with those of the primary branches ; by degrees the principal stems
of the loop are separated again, become larger, and give ofi' a transverse branch, which
fixes itself to the upper anterior edge of the then low median septum.

In 1847 A. d'Orbigny proposed his excellent genus Terebratella, giving the full-grown
condition of Terebratula dorsata, Gmelin, as his type. King's Terehratula Sozccrbil, from
the Straits of Magellan, is nothing more than a rust-coloured example of Terebratella

11*

78 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

dorsata. It is always necessary to give the characters oi c species from its adult condi-
tion, noting the changes its apophysary system undergoes during the different stages in
its development.

In 1845 Dr. Philippi described, under the name of Terebratula lupimis, a young smooth
examjjle of Terebratella dorsata, in which the dorsal valve still 'detains the elevated
Magasella septum. The type is preserved in the Berlin Museum. Philippi did not
figure his so-termed species, and I am indebted to Prof. E. v. Martens for a series of
excellent figures of the species (PI. XIV. figs. 20 a, h, 21 a).

In 1833 Prof. Owen described, with great care and minuteness, the soft parts of the
animal in the sjiecies under description. He says that " the arms and viscera, as in
Lingttla, are inclosed between the lobes of the mantle, which are precisely adapted to the
inner surface of their corresponding valves, and are in such close contact with them as to
require great care in separating the valves from them. That lobe of the mantle which
corresponds to the perforated valve, is traversed longitudinally by four large vessels ; the
opposite lobe is similarly traversed by two such vessels. . . . The margins of the mantle
are thickened . . . the marginal cilia are so minute as only to be perceptible by means
of a lens. At the posterior part of each of the lobes the expanded fleshy extremities of the
muscles are seen ; those which were attached to the perforated valve being nearer the
hinge by their whole length, than the anterior pair of the opposite valve. Each of tlie
oval muscular disks is composed of an anterior larger muscle and a posterior smaller one.
Through the transparent mantle may also be seen the green-coloured follicular liver
intervening between and stirrounding the muscles, and the folded ciliated arms." Prof.
Owen then describes at some length the great arterial trunks, adding that " The size of
these vessels at once suggests their subserviency to other purposes than that of merely
returning the blood necessary for the nutrition of the mantle. . . . Corresponding to the
large branchial veins there appear under the microscope much smaller vessels, which I
regard as the branchial arteries ; these run parallel with the middle of the branchial
veins, and terminate in the margins of the mantle from which the veins commence.
These margins present the following appearances when viewed with a high magnifying
power : — they are puckered at regular distances, the puckering being apparently caused
by the insertions of delicate cilia, which pass as far within the mantle as they project
beyond it ; in the interspaces of the cilia the margin of the mantle is minutely fringed :
and within this fringe is a canal, which extends itlong the whole circumference of the
lobe, and from which the branchial veins appear to take their origin : the marginal canal
is contracted where the cilia are inserted into it, which gives it a sacculated appearance,
like that of the canal of Petit in the human eye. The uniform results of repeated obser-
vations on aU the specimens of Terebratula wliich I have had at my disposal, convinced
me that the vascular mantle was the chief, if not the sole respiratory organ ; and the
utility of the marginal cilia in reference to this function can now be readily appreciated,
in consequence of the discovery of the i-emarkable property which cilia possess of
exciting determinal currents in the surrounding water."

After having stated so much. Prof. Owen then describes the shape and double attach-
ment of the loop, and adds, " the interspace between the two folds of the calcareous loop
is filled up by a strong but extensile membrane, which binds them together, and forms a

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 79

protecting wall to tlir^ 'viscera ; . . . The arms in Ter. chilensis, when detached from the
supjoorting processes and unfolded, exceed the length of the shell by two thirds of that
length ; and their length is to their breadth as eight to one. Their stem, from which
the cilia airse, as it has not to execute the movement of Lingula, so it is much more
slender. The cilia, therefore, are proportionally increased, in order to excite the neces-
sary currents in the Avater ; which, being directed between the folds of the arms
towards the mouth, as to a focus, carry thither tlie nutrient molecules, which are retained
by the natural sieve formed by the decussating cilia of the terminal processes in front of
the mouth ; and though this apparatus is apparently less perfect than in Limjula, it is
evidently adjusted in due relation to the support of so small a mass of body as exists
in Tercbratula."

Prof. Owen then refers to the muscles and peduncle; but as these bear a general
resemblance to those already noted in Waklheimia and in other genera, we will not
repeat his description here. He also describes the alimentary canal, the oesophagus,
and liver: this last he states to be "a bulky gland of a green colour and minute
follicular texture ; it is disposed in two principal masses, which lie on each side of the
alimentary canal, and between the two lateral arches of the testaceous loop iu tho^p species
of Terehmtula which possess that appendage ... In two of the larger specimens of
Ter. Sowerbii, the ova were lodged external to the liver, and had also insinuated themselves
between the layers of the mantle-lobes, in close proximity to, and partly surrounding,
the branchial vessels. They are probably discharged in this way from the mantle,
having previously been exposed to the influence of the branchial currents. ... In
dissecting a Terehratula I have found it most convenient to cut transversely through the
perforate valve, so as to leave the orifice and the pedicle connected to the opposite valve,
by which means the disposition of the muscles is satisfactorily seen, and the delicate parts
within are less liable to be disturbed than by attempting to separate the entire valve."
I regret not being able to reproduce Prof. Owen's admirable illustration.

The muscular system of Terehratula dorsata has also been described by Prof. W. King
in the Ann. & Mag. Nat. Hist. ser. 1, vol. xviii. p. 39, 1846.

38. Terebratella transversa, Sowerby, sp. (PI. XVI. figs. G-9.)

Terebrutula Iramversa, G. B. Sowerby, Descriptions of thirteen new Species of Brachiopoda, Proc. Zool.
Soc. 184G, p. 91 ; Tlies. Conch, vol. i. p. 3G1, ])1. 72. figs. 114, 115, 1846.

Terehratula caurina, Gould, Proc. Boston Soc. Nat. Hist. iii. p. 347, 1850 ; Gould, U. S. Esplor. Exped.
xii. Shells, p. 468, pi. 44. fig. 582 ; Otia Conch.p.97, 1862; Carpenter, Supp. Rep. Brit. Assoc. 186.3, p. 636.

Terebratella caurina, E. Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. Wissensch.
Wien, Bd. xxsvii. p. 207, 1859.

Terebrutula canrena, P. P. Carpenter, Rep. Brit. Assoc. 1856, p. 298.

Terebratula (Terebratella) transversa, L. Reeve, Conch. Icon. INIonog. Ter. pi. v. fig. 22, I860 ; A Revision
of the History, Synonymy and Geograxihica! Distribution of the Recent TerebratuLe, Ann. & Mag. Nat.
Hist. 3rd ser. vol. vii. ]>. 176, 1861.

Terebratella caurina, Dall, Amer. Journ. of Conch, vol. vi. p. 119, pi. vi. figs. 1, 2, 3, 1870.

Terebratella occidentalis, Dall, Proc. Acad. Sci. of California, vol. iv. p. 182, pi. 1. fig. 7, 1871.

Terebratella transversa, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 185.

Terebratella occidentalis, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 181.

80 BE. T. DAVIDSON ON EECENT BEACHIOPODA.

Terebratella transversa, J. E. Whiteaves, Ou some Marine Invertebrata from the "West Coast of North
America, Canadian Naturalist, n. s. vol. viii. p. 468, 1878, and On some Marine Invertebrata from Queen
Charlotte Island, Keport Geol. Surv. Canada, 1878-79, p. 195 (1880).

Shell very variable in shape, usually quadrispherically transverse, wider than long,
broadest posteriorly or near the hinge-line, which is very obtusely angular, almost straight,
very little shorter than the breadth of the shell ; marginal line flexuous and sinuated in
front. Dorsal valve moderately convex, channelled longitudinally along the middle by
a concave depression or sinus. Ventral valve much deeper than the dorsal one, with a
longitudinal elevation or fold extending from the beak to the front ; beak short, slightly
incurved, and truncated by a large incomplete foramen, margined anteriorly by a portion
of the umbo of the opposite valve, and laterally by two small deltidial plates ; beak-
ridges strongly defined, leaving between them and the hinge-line a flat or gently con-
cave smooth area. Surface of valves either smooth or more or less covered with faint
or strong angular ribs, here and there bifurcating, or with a short rib interpolated
between the larger ones. Shell-structure perforated by minute canals. In the interior
of the dorsal valve the hinge-plate is divided ; cardinal process small, and from under it
a mesial septum of small elevation extends to about half the length of the valve. Loop
long, doubly attached, first to the base of the hinge-plate, then to the anterior extremity
of the mesial septum by means of an oblique lamina given off from about the middle
of the length of the principal stems of the loop, when, after having attained their greatest
length, they become reflected in the shape of a loop. Colour varying from light ashy
yellow to a light or dark livid purple or red mixed with yellow, deeper in colour on the
lines of growth. Length 1 inch 3 lines, breadth 1 inch 7 lines, depth 10 lines.

Hab. Off Vancouver Island, mouth of Cumshewa Harbour, in 20 fathoms; Houston-
Stewart Channel, in 15-20 fathoms (Whiteaves) ; Puget Sound to Sitka (Swan), Alaska
territory, peninsula of Aliaska ; Neeath Bay, from Aleutian Islands to Oregon (Dall) ;
coast of California at Monterey (Cooper and Dall) ; Catalina Island (Cooper).

Obs. Dall justly observes, in his description of this species, in the ' American Journal
of Conchology ' for 1870, that " it presents every possible variation from longitudinally
oval to quadrispherically transverse, that many are unsymmetrical, and most of them
overgrown with Polyzoa, Serpulse, and Corallines." He also mentions that " some
specimens have from thirty to forty ribs or many fewer, and varying very much in
prominence; some have none at all, and others have theu* valves smooth and half
ribbed, some ribbed only on the umbones, others again near the margin." I have
detected all these modifications even in the limited number of specimens I have been
able to examine.

To the completely smooth examples, Sowerby, in 1846, gave the name transversa ; to
a ribbed individual, Gould, in 1850, applied that of caurina (PL XVI. figs. 10-12), and, in
1871, Dall named a red variety, from the coast of California, Terebratella oceideiitalis.
Peeling somewhat uncertain with respect to the last-named species, I forwarded to Mr. Dall
a red specimen, of which I give figures (PI. XVI. figs. 13 & 11), and which agreed in every
detail, except in colour, with specimens from Sitka and Vancouver Island. In returning

DE. T. DAVIDSON ON EECENT BEACHIOPODA, 81

it to me Mr. Dall wrote that it was his Terebmtella occkleiitalis, which may prove to be a
southern race of Terehratella transversa of Sowerby ; and I quite believe this to be the
case. The lines of growth, Mr. Dall states (under T. caurma, Eevision of the Terebratulidae,
Amer. Journ. Conch, vol. vi. 1870, pp. 120, 121), " are usually strong and often imbricated,
especially when the radiating ribs are strong. . . . The punctures are smaller, more cir-
cular, and fewer in number than in Terehratella pulvinata. An examination of the young
shells only about '2 inch in extreme width, showed some interesting points. The septum
is calcified very early, and is thick, prominent, bifurcate at its extremity, and serrated on
its anterior edge. The bifurcation is the first indication of the septal processes, which
are the last to be calcified ; and when the extremely thin hcemal processes are yet incom-
plete, the young shell closely resembles a Magas. In the beak of the neural valve just
inside the foramen, is a very prominent thin lamina or septum which half closes the
foramen. In the adult the muscular system is not largely developed. The pedicel
muscles are the strongest. The cardinals are slender and their bases are spread over a
wide extent of the neural valve, but the muscular impressions are imperceptible. The
adductors are small and slender. The brachia foUow the lateral loops of the apophyses
and cross below the mouth on the reflected portion and the septal processes. There is
no central spiral lobe. The fringes are in a single row, flattened and extremely thin ;
in an adult they are about "IS inch long. They are much more slender than in Terebra-
tulina or Megerlia. When fully extended they are far from the margin of the valves.
The mouth is circular, situated between the adductors. The visceral part of the system
is protected by a tliin tough membrane. The colour of the animal is reddish or brownish,
the ovaries vary in the same way. The perivisceral fluid is of a reddish-yeilow colour.
The umbones of both valves are generally eroded by contact with stones. The animal
seemed to have the power of turning half around on its peduncle at will."

Although the name traiisversa, Sowerby, should be retained for the species, the
smooth variety is less abundant than the costated one. The ribs are, in some specimens,
quite simple, and the variety occidentalis has, according to Dall, been sometimes mistaken
for the Waldheimia Grayi, Davidson, from Japanese waters.

39. Terebratella coreanica, Adams & Reeve, sp. (Plate XIII. figs. 3-9.)

Poulette de la Tartarie, Lamanon, Voyage de la Perouse autour du Monde, vol. iv. p. 119, pis. 1 and 8,
1797.

Terebratula coreanica, Adams & Reeve, Voyage of H.M.S. ' Samarang,' p. 71, pi. xxi. fig. 3, 1850.

Terebratella coreanica, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 3G7, 1853.

Terebratella Bouchardii, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 367, 1852, and Proc.
Zool. Soc. 1852, pi. xiv. figs. 4-6; Woodward & Gray, Cat. of the Brach. in Brit. IMus. p. 88, 1853;
E. Suess, Uebcr die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissensch. Wicn, p. 206,
1859.

Terebratella miniata, Gould, Proc. Boston Soc. Nat. Hist. vol. rii. p. 323, 1861.

Terebratula {Terebratella) Coreanica, Reeve, Monogr. of Terebratula, Conch. Icon. pi. rii. fig. 28, a,b,
1861 ; A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. ii. p. 99, 1863; L. v. Schrenck, Reisen und
Forschungcn im Amur-Landc, Zool. p. 468, pi. xviii. fig. 7, 1867.

? Terebratella Lamanoni, L. v. Schrenck, ibid. 1867.

? Terebratella Coreanica, Carpenter, Supp. Rep, Brit. Assoc. 1863, p. 636.

82 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

Tercbratella Coreanica, Dall, Amer. Journ. Conch, vol. vi. p. 121, 1861, and Proc. Acad. Nat. Sci.
Philadelphia, p. 183, 1873 ; Davidson, Proc. Zool. Soc. 1 871, p. 304, pi. xsxi. figs. 4-5 ; G. Dunker,
Index IMollusc. Maris Japonici, p. 252, 1882 ; C. E. Leschke, Japonische Meeres Conchylien, Suppl.
p. 181, 1884.

Shell large, semicii'cular, or somewhat transversely or elongated oval, broadest poste-
riorly, slightly winged, with an almost straight or obtusely angular hinge-line, or broader
about the middle, with a more obtusely angular hinge-line ; lateral margins flexuous, more
so in front. Dorsal valve convex, sometimes ventricose, channelled or depressed longi-
tudinally along tlie middle. Ventral valve deeper than the dorsal one, strongly keeled
longitudinally ; beak incurved and truncated by a circular foramen, incomplete in some
specimens, in others margined anteriorly by a deltidium in two pieces ; beak-ridges
strongly marked. In the interior of the dorsal valve the hinge-plate and cardinal process
are large and well defined ; a mesial septum of small elevation extends to about half the
length of the valve. Loop large, attached to the base of the hinge-plate and by a
transverse lamella to the anterior extremity of the septum before again proceeding and
doubling itself in the shape of a loop. Shell smooth, orange-red throughout, or fulvous-
white rayed with bright red, and traversed by concentric lines of growth stained with
red at their edges ; shell punctate. Proportions variable, a large example measured :
length 1 inch 10 lines, breadth 1 inch 11 lines, depth 1 inch 1 line.

Bah. Corean Archipelago (Belcher) ; Ilakodadi, Japan, in 7 fathoms, and Straits of
Korea in 48 fathoms (A. Adams) ; dredged also at Hakodadi, in 1868, by L. v. Schrenck,
and in 1872 by Capt. St. John in Tsuga Strait, in 35 fathoms ('Sylvia' Expedition);
Sea of Tartary (Lamanon, Voyage de la ' Perouse,' 1798).

Ohs. This beautiful large red species was dredged, if I am not mistaken in my identi-
fication, by Lamanon in 1797, iu the Sea of Tartary. He described and figured the shell,
its loops and labial appendages, with tolerable accuracy, and showed that its loop was
twice attached, although his large figure 11 is evidently incorrectly drawn. He gave it
the name of " Poulette de la c6te de Tartaric," and subsequently, in 1867, Dr. L. v.
Schrenck named it Terebrattila Lamanoni, after its discoverer. In 1850, Adams and
Reeve described and figured two smaller examples, delicately painted with irregular
crimson-scarlet rays, dredged by Sir Edward Belcher during the voyage of H.M.S.
' Samarang,' under the name of Terehrtdella Coreanica; and this name must be retained
for the shell. To some larger examples Gould, in 1861, gave the name of Terehratella
miniata, and I now consider the shell I described in 1852 by the name of Terehratella
BoucJiardii to be merely an elongated bleached example of Terehratella coreanica. This I
am more ready to believe, as I subsequently procvired an exactly similar-shaped specimen
from tlie locality where Terehratella coreanica abounds, marked with red as in that species.

Terehratella coreanica is extremely variable in shape, as may be seen from the illus-
trations I give of it in PI. XIII. figs. 3-9. The largest examples I have seen of the shell
were obtained at Hakodadi during Dr. v. Schrenck's Russian Government dredging-expe-
dition in Amur Land, 1854-56. Dr. v. Schrenck gives seven figures in pi. xviii. of his
work ; but fig. 7, representing the loop, is not correct, as I ascertained from a type specimen
he kindly presented to me shortly after his return. In the specimen in question the

DE, T. DAVIDSON ON RECENT BRACHIOPODA. 83

reflected portion of the loop was mucli larger, and agreeing with the figure I give of it
on Plate XIII. fig. 7.

I may also mention that searcli was made at the Jardin des Plantes for Lamanon's
specimens, but none of them could be discovered.

Having examined some young examples of the shell under description, I found that its
loop underwent similar modifications to those I have described as taking place in
Terehratella ruhicunda.

40. Terebratella Blanfordi, Dunker, sp. (Plate XV. figs. 9-12.)

Terebratula Blanfordi, Dunker, Index Mollusc, maris Japonici, p. 251, pi. xiv. figs. 4, 5, 6, 1882.

Sliell thin, nearly as wide as long, rotundate quadrate, lateral margins moderately
curved ; hinge-line obtusely angular, front line long, with a greater or less inward curve.
Dorsal valve moderately convex, with a broad shallow depression commencing at a short
distance from the umbo, and gradually widening as it approaches the front. Ventral valve
deeper and more convex than the dorsal one, with a similar broad depression commencing
at a short distance from the beak and extending to the front. Beak rather small, incurved,
and truncated by a circular foramen partly margined by a deltidium ; beak-ridges sharply
defined. In the interior of the dorsal valve the loop is long and doubly attached, first to
the hinge-plate and then to the median septum, before becoming reflected. Surfaces
smooth, marked here and there with fine concentric lines of growth. Colour dull yellow.
Length of a large specimen 13, breadth 12, depth 8 lines.

Ohs. This remarkable and well-characterized species is well described and figured by
Dunker, who gives as its habitat Wakayama, Japan. It varies somewhat in contour ;
some specimens are more circular, and in some the frontal indentation is greater than in
others. Terehratella Ula nfordl is associated in the same sea-bottoms with Terehratullna
Crossil, Davidson, and Waldhe'imia Raphaelis, Dall.

41. Terebratella spitzbergensis, Davidson. (Plate XVI. figs. 1-5.)

Terebratula , Lyell, On the Proofs of a gradual Rising of the Land iu certain parts of Sweden,

Phil. Trans. Roy. Soc. 1835, p. 3G, pi. ii. figs. 32, 33.

Terebratula caput -serpentis, Hisinger, Lcthfea Suecica, p. 83, 1837 (not of Linnaeus).

Terebratella Spitzbergensis, Da-iddson, Proc. Zool. Soc. 1852, p. 72; Ann. & Mag. Nat. Hist. 2nd ser.
vol. xvi. p. 442, pi. X. fig. 3, 1855; and Proc. Zool. Soc. 1871, p. 305, pi. xxx. fig. 13; M'Audrew,
List of the MoUusca from Spitzbergen, Ann. & Mag. Nat. Hist. 2nd ser. xvi. p. 465, 1855 ; O. Torell,
Bidrag Spitzbergens MoUuskfauna, p. 121, pi. i. fig. 1, 1859 ; E. Suess, Ueber die Wohnsitzeder Brachio-
padcii, Sitzungsb. k. Akad. Wissench. Wien, p. 204, 1859 ; L. Reeve, Conch. Icon. jjl. vii. fig. 2, 1861,
and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 178, 1861.

Magasella Spitzbergensis, Dall, Amer. Journ. of Conch, vol. vi. p. 37, 1870; Terebratella, id. Proc.
Acad. Nat. Sci. Philadelphia, p. 185, 1873.

Terebratella spitzbergensis, Jeffreys, Proc. Zool. Soc. 1878, p. 409, pi. xxiii. fig. 2 ; H. Priele, The
Development of the Skeleton in the genus JValdheimia, Arch, flir Mathematik og Naturvidenskab, pi. vi.
1877; G. Dunker, Index Mollusc, maris Japonici, 1882, p. 252.

Shell small, ovate, longer than wide. Valves uniformly and nearly equally convex ; no
fold or sinus in either valve ; beak in ventral valve moderately produced, incurved and

SECOND SERIES. — ZOOLOGY, VOL. IV. 12

84 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

truncated by an incomplete, longitudinally oval foramen, margined anteriorly by the
ximl)0 of the dorsal valve and by two small lateral triangular deltidial plates ; beak-ridges
not very sharply defined. Surface of valves smooth, strongly punctate, and marked by
fine concentric lines of growth. The apophysary system in dorsal valve composed of
a doubly attached loop extending to about two thirds of the length of the valve, first
attached to the base of the hinge-plate, the principal stems widening gradually and,
at about half their length, becoming attached to the upper edge of an elevated median
septum, then again extending towards the front before becoming reflected. Colour light
whitish yellow. Length 4^, breadth 3|, depth 2| lines.

Hab. Homsund and Bellsund, Spitzbergen, 40 to SO fathoms (Torell) ; Wellington
Channel (Belcher) ; Shetland, 35 miles N.N.W. of Unst, in 90 to 100 fathoms ; Channel
Slope, about 185 miles from Cape Clear and Usliant, and 165 miles from the Scilly Isles,
in 358 fathoms ; Channel Slope, 339 fathoms ; otf Cape St. Vincent on the coast of Spain,
292 fathoms (Jeffreys) ; Gulf of St. Lawrence (P. P. Carpenter and Whiteaves) ; Japanese
Waters (A. Adams) ; off Iceland (' Valorous ' Expedition) ; Possil at Uddevalle (Hisinger
and Jeffreys) ; and in another raised bank near Christiauia in 1866 by Messrs. Crosskey
and Robertson.

Ohs. I have seen a number of specimens of this small well-marked species ; none of
them exceed the dimensions above recorded. Terebratella spitzbergensis evidently
enjoys an extended geographical range.

In 1834 Sir Charles Lyell collected in a Swedish postglacial deposit a single ventral
valve of this brachiopod, while investigating the proofs of a gradual rising of the land
in certain parts of Sweden. He simply called it a Terebratula, and gave two figures of it
in the ' Philosophical Transactions ' of the Royal Society for 1835. According to Torell
the species was confounded in 1837 by Hisinger with TerebraMina caput-serpentis.
In 1852 I described and figured the shell in the Ann. «& Mag. Nat. Hist, from a
perfect specimen lent to me by Mr. H. Cuming, and then gave it the name of Terebratella
Spitzbergensis, which it has since retained. In 1859 Torell published an incomplete
figure of the loop, but sufficient to show that it was doubly attached as in Terebratella.
The young of Terebratella spitzbergensis have not yet been examined; but in a paper by
Herman Priele on 'The Development of the Skeleton in the genus Waldheimia,' a. whole
plate is devoted to enlarged illustrations of the loop, and the author remai^ks that in one
example " remnants of the lateral walls are still left on the lamel-processes at their point
of connection with septum, which signifies an earlier stage like that in Tf^aldheimia."

42. Tekebbatella btjbicunda, G. B. Sowerby. (Plate XV. figs. 15-29.)

? Terebratella sanguinea, Quoy & Gairaard, Voyage de TAstrolabe, Zool. vol. iii. p. 556, pi. 85. figs. 7-8,
1834 (not T. sanguinea, Cbemnitz).

Terebratella rubicunda, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 92, and Tbes. Coucb. i. p. 351,
pi. kx. figs. 45-47, 1846.

Terebratella inconspicua, Sowerby, Proc. Zool. Soc. 1846, p. 93, and Tbes. Concb. p. 359, pi. Ixxi.
figs. 102-104, 1846.

II alionia Fatewdewwem, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol, v. p. 475, pi. xv. fig. 1, 1850.

DE. T. DAVIDSON OX EECENT BEACHIOPODA. 85

Terebratella rubicunda, Davidson, Aim. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 36", 1852 ; Woodward

6 Gray, Catalogue of the Bracliiopoda in the British Museum, p. 89, 1853 {T. inconspicua is now
considered a synonym of T. rubicunda) ; E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb.
k. Akad. der Wissensch. Wicii, p. 207, 1859 (T. inconspicua and a syn.) ; L. Reeve, Conch. Icon. pi. vii.
fig. 27, 18GI {T. inconspicua a syn.) ; Dall, Amer. Journ. Conch, vol. \\. p. 117, 1870, and Proc. Acad.
Nat. Sci. Philadelphia, 1873, p. 185.

Magasella inconspicua, Dall, Amer. Journ. of Couch, vol. vii. p. dl , 1871, and Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 189.

Terebratella rubicunda, F. W. Hutton, Marine Mollusca of New Zealand, p. 85, 1873.

Shell somewhat orbicular or triangularly ovate, widest about tlie middle, acuminated
posteriorly ; dorsal valve moderately convex, channelled along the middle by a broad
concave sinus, commencing at the umbo and extending to the front, where it is produced
a little beyond the lateral curved margins of the valve. Marginal line flexuous on the
sides. Ventral valve deeper than the dorsal one, with a convex, well-defined, mesial fold
extending from the extremity of the beak to the front ; l)eak incurved and truncated by
a large circular foramen, lying close to the umbo or just separated from it by two rather
large deltidial plates that barely meet in the middle ; beak-ridges sharply defined. Surface
of valves either entirely smooth or more rarely with small short rounded ribs commencing
at a short distance from the lateral and frontal margins of the valves ; surface of valves
crossed by concentric strongly marked lines of growth. In the interior of the dorsal
valve the hinge-plate is well defined, with a cardinal process at its posterior extremity.
A mesial septum of small elevation proceeds from the base of the hinge-plate to about
one half the length of the valve. Loop doubly attached, first to the base of the hinge-
plate, and then by a transverse lamella proceeding from about the middle of the
length of the principal lamella to the anterior extremity of the septum, when, after
again extending a little further, the lamell.Te become reflected and united. Colour
pale or deep red, sometimes colourless. Length 1 inch 1 line, breadth 1 inch, depth

7 lines.

Sab. Fauveau and Cook's Straits, New Zealand ; Dusky Bay (Hutton).

Ohs. Terebratella rubicunda is an exceedingly abundant shell in the seas of New
Zealand. It varies much in shape and character from the young up to the adult condition,
and its loop passes through several modifications during the progress of growth.
The youngest individual I have been able to examine measured three lines in length ; at
this stage and for some time after its septum is remarkable in shape and of considerable
elevation as in Ilagasella, but low at its origin under the hinge-plate. It soon assumes an
upward concave curve, to be followed by another still more oblique ; where it attains
its highest elevation, a flattened plane occurs and then gradually thins out by an abrupt
inward curve, until it reaches nearly to the bottom of the valve, the anterior half of
the septum presenting the form of a wide, elevated, flattened plate. In the young
stage under description the principal laminae or stems of the loop, after being attached
to the hinge-plate, form a curve and become fixed by their anterior edges to the
lateral sides of the septum ; a little higher up, and attached to the edge of the septxim,
are two wide, curved, disunited anchor-shaped lamellije. To this immature condition
I gave in 1850 the name Waltonia Valenciennesii, which must be expunged. To a

12*

86 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

shell in the same condition, or a little older, G. B. Sowerby, in 1846, gave the name of
Terebratula inconspmict. In 1852 I expressed the opinion that the shell " seems to be
only a young and ill-gvown specimen of T. riihicmida;" and in this opinion S. P.
Woodward, E. Suess, and L. Reeve have concurred. Mr. Dall, however, maintains
it as a distinct species, and places it in his genus Ifagasella. When a little older, or at
about four or five lines in length, the septum becomes very much less elevated, and the
principal lamellge approach closely to the septum, where they become attached prior to
continuing their course and becoming reflected. In the adult or full-grown state the
septum is quite low, and at about half their length the principal lamellse, which are now
wide apart, give off a long, oblique lamella, which connects them to the anterior
extremity of the septum. A glance at the figures on Plate XV. will show these different
conditions better than any verbal description.

Groups of specimens at different stages of growth are often found attached to a single
adult example. The shell is generally smooth throughout, but a tendency to plication is
not uncommon on the anterior portion of the shell. The peduncle is very short.

Mr. Donovan states, in the second volume of his ' Naturalist's Repository,' that
Solander had given the MS. name of rubicunda to the shell we noAV kuow^ as Ki-aussina
rubra of Pallas, 1766 ; but as Solander did not publish his name, that of rubicunda,
Sowerby, must be retained for the shell under description.

The intimate shell-structure of Terebratella rubicunda has been carefully investigated
by Dr. W. B. Carpenter. In plate iv. of his chapter on the structure of the shells
of Brachiopoda, contributed to vol. i. of my ' British Possil Brachiopoda,' he gives
three enlarged figures, one of these, which we reproduce (PI. XV. fig. 25), is a portion of a
vertical section of the loop-bearing valve, taken in the transverse direction through the
origin of the calcareous appendages, -nhich shows that the latter are not traversed by
canals. In this figure the ordinary trumpet-like form of the vertical passages is
shown, and the remarkable contractions which they exhibit in the inner and (probably)
later-formed layer ; in Plate XV. fig. 26 the occasional l)ifurcation of the vertical
passages is represented.

43. Terebratella prontalis, Middendortf, sp. (Plate XV. figs. 1-8 a.)

Terebratula frontuUs, Middenclorff, Beitriige zu einer Malacozool. Rossica, iii. 1849, Mem. Acad. St.
Pctersbourg, t. vi. p. 518 ; aud Reise in d. ausserst. Nordeu und Osten Sibiriens, 1851, Bd. ii. jj. .LMl,
t. xviii. figs. 9-li; E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch.
Wien, p. 204, 1859; Dall, Amer. Jourii. of Conch, vol. vi. p. 1.23, 1870; Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 184 ; Dall, Report on the Brachiopoda of Alaska and the adjacent shores of North-
west America, ibid. 1877, p. 15G; Duuker, Index Mollusc, maris Japonic!, p. 252, 1882.

Shell somewhat subpentagonal, longer than wide, broadest about the middle, mar-
ginally curved, slightly indented in front. Dorsal valve posteriorly evenly convex,
anteriorly divided by a narrow^ longitudinal depression or groove, commencing at a very
short distance from the front margin. Ventral valve rather deeper than the dorsal one,
w^ith a very slight elevation close to tlie margin; beak rather large, truncated at right
angles by an unusually large incomplete foramen, posteriorly margined to a considerable

DK. T. DAVIDSON ON EECENT BEACHIOPODA. 87

extfint by tlie umbo of the dorsal valve and by two very small rudimentary deltidial
plates ; beak-ridges sharply defined, leaving between them and the hinge-line a small
flattened space. Hinge-line obtusely angular. Surface of valves smooth, marked with
strong concentric lines of groA\th ; shell-punctures rather large; and soin(>what widely
interspaced. In the interior of the dorsal valve the cardinal process is small, the hinge-
plates are disunited and form two concave projections, on each side of w^hich deep
dental sockets are situated. The principal lamella; of the loop are attached to the
bases of the hinge-plate, and these by a curve meet a slightly raised mesial septum, to
which they lioconie again attached ; at a short distance from this second attachment the
lamellae become reflected in a very remarkable and unusual manner. The large paired
adductor muscular impressions are situated at the bottom of the valve, and at some
distance from the mesial septum or ridge. In the ventral valve the curved articulating
teeth arc large and powerful. Colour ashen or yellowish grey. Length of a large
specimen 11 lines by 10 in breadth and 6 in depth.

Hab. Western Aleutians from Atka Island westward ; Atka, Amchitka, Attn (Dall) ;
Ocbotsk Sea (Middendorff ) ; Japan seas (Capt. St. John). From low water to 45 fathoms ;
abundant in 10 fathoms.

Obs. This is a very good and well-characterized species, well but not completely fio-ured
by Middendorff in 1819. The shell was subsequently al)undantly collected by Mr. Dall
and Capt. St. John. The Japanese examples are a good deal smaller than those figured
by the Eussian author, as well as those dredged by Dall at Atka Island, in the Aleutian
channel. Their interior is exceedingly remarkable, and differs in detail in many respects
from that occurring in the larger number of species of the genus, first in the shape of the
loop, and secondly in the position and dimensions of the adductor muscular impressions,
which are very powerful. These characters and differences will become at once apparent
by a glance at the figures, which I have drawn with all possible care and accuracy. The
shell is thick and presents a coarse appearance.

44<. Teuebratella cruenta, Dillwyn, sp. (Plate XIV. figs. 1-8.)

Anomiu saiif/iiinca, Solander, MS. Portland Cabinet; Leverian Cat. sec. part 15.

Tert'brutuhi saiirjiiinea, Leach, Zool. Misc. p. 7Q>, tab. xxxiii. 1814 (not Chemnitz).

? TerebratuJa sanyuinea, Lamarck, An. sans Vert. voL vi. p. 247, 1819 (not Chemnitz?).

Terebratula cruenta, Dillwyn, Descrip. Cat. Recent Shells, vol. ii. p. 295, 1817.

Terebratula sanffuinea, E. Donovan, Naturalist's Repository, vol. i. pi. 34, 1823.

Terebratula Zelaiidica, Deshayes, Revue Zoologique par la Soc. Cuvierienne, p. 359, 1839, and Mag.
de Zoologie, Mollusques, pi. 42, 1841.

Terebratula rubra, G. B. Sowerby, Thes. Conch, i. p. 345, pi. isviii. figs. 9-11, 1846 (not Pallas).

Terebratula Zelandica, G. B. Sowerby, Thes. Conch, p. 361, pi. Ixxii. figs. 111-113, 1846.

Lampas sarir/uineu.f, Calonne, Cat. Humphrey, MS.

Terebratella Zelandica, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vo p. 367, 1852.

Terebratella Evansii, Davidson, Proc. Zool. Soc. 1852, p. 77, pi. xiv. figs. 7-9.

Terebratella cruenta, Woodward and Gray, Cat. of Brachiopoda in the Brit. ^lus. p. 89, 1853.

Terebratella Zelandica, E. Suess, Ueber die Wohnsitze der Brachiopodcn, Sitzungsb. k. Akad. der
Wissensch. AVien, Bd. xxxvii.p. 207, 1859.

88 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

TerebrafeJla {Tcrebratuhi) crventa, L. Reeve, Conch. Icon. pi. v. fig. 20, a, b, 1860.
Terebratella {Magus) Evrinsn, L. Reeve, Concli. Icon. pi. viii. fig. 31, 1861.

Terebratella cruenta, Dall, Proc. Acad. Nat. Sci. Philadelpliia, 1873, p. 183; F. W. Hutton, Catalogue
of the Marine Mollusca of New Zealand, p. 85, 1873.

Shell rather large, somewhat subpentagonal, subtransverse, ventricose, longer than
broad. Dorsal valve convex, channelled longitudinally along the middle by a well-defined,
flattened, mesial sinus or depression. Ventral valve deeper and moi-e convex than the
opposite one, with a longitudinal mesial fold of moderate breadth and elevation, some-
what flattened, extending from the beak to the front; margins flexuous both laterally
and in front ; beak incurved and truncated by a large circular foramen, separated from
the hinge-line by a deltidium in two pieces ; beak-ridges not very sharply defined. Sur-
face of valves rad lately costellated ; ribs narrow, numerous, increasing in number
at various distances from the beak and umbo through bifurcation and the interpola-
tion of smaller and shorter riblets between the larger ones ; surface of valves crossed
at various distances by concentric lines of growth. In the interior of the dorsal
valve the cardinal process and hinge-plate are large and well defined ; the mesial septum,
of low elevation, extends to lialf or a little more of the length of the valve. Loop large,
doubly attached, the principal stems, before attaining their greatest length, give oflP a
flat oblique lamella, which becomes fixed near the anterior extremity of the septum, the
lamella proceeding again and doubling in the shape of a loop. Colour sanguineous or
paler red, deepest in intensity at the lines of growth. Length 1 inch 10 lines,
breadth 1 inch 11 lines, depth 1 inch 2 lines.

Mab. Very abundant in Cook's and Fauveau Straits, New Zealand.

Ohs. This beautiful shell has been rather unfortunate on account of the many con-
fusing names it has received. In 1823, Donovan, in vol. i. of his ' Naturalist's Reposi-
tory,' described and figured the shell, and enters into long details with respect to its early
history. He informs us, that it is one of those very choice accessions to the conchological
knowledge of the last century, that it occurred to them upon the coast of New Zealand,
and that after the Banksian Cabinet had been supplied, duplicates were presented to
Dr. Solander, Captain Cook, the Duchess of Portland, Mr. Cracherode, and Mr. G.
Humphrey, and to some others. That it was named and described for the first time, in
manuscript, by Solander under the name oi Anomia sanguinea *, was subsequently so desig-
nated in the museum of the Duchess of Portland ; and that it appeared under the same
appellation in the catalogue of that museum pul)lished in 1786. Donovan complains
very bitterly that Dillwyn should not have adopted, in 1817, Solander's manuscript name,
and should have given it instead that of cruenta, a name Solander had also made use of
in manuscript for another species. Dillwyn was, however, justified in rejecting Solander's
designation, since Chemnitz had previously, in 1785, applied the name sangu'mea to
another species ; for manuscript names cannot claim a right to priority over any others that
have been really published. It is to be regretted, however, that Dillwyn had selected for the

* " Obovato longitudinaliter sulcata, triloba : sinu profundo nate producta latere angulata foramen ambiante.
Solander's Miiii —Bab. in 0. Pacifico, G. R. Forster "(Donov. Nat. Rep. I.).

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 89

New Zealand species the name of crucnta, wliicli had, in manuscript, been applied hy
Dr. Solander to another species.

Although a well-marked species, TerehrcUella crueiila, Dillwyn, has been confused
by some conchologists with others to which it does not belong-, such as with the Kraussina
rubra of Pallas (Solander's MS. Anomia ruhicunda). Its young stage received from myself
the name of Terebratella Ecansii before I had ascertained that in the young the loop
presented the character of Jf«/7«'s<?^Za. All the early authors prior to 1817 knew the shell
we are describing by the name given to it by Solander. It is so named in the Levcrian
Cabinet, sec. j)art 15 ; also in Dillwyn's Couch, i. p. 293, 21 ; and in Leach's Zool. Misc. x.
p. 76 ; and in Lamarck's ' An. sans Vert.' vol. vi. p. 217 (1819), for he refers to Leach's Zool.
Misc., but was evidently in error Avhen he gives, as its synonym, the Anomia capensia of
Gmelin and Chemnitz. Terehratella cruenta, like all its congeners, is very vai-iable in
shape, and its loop passes through several metamorphoses, from the very young state up to
the full-grown condition. I have already given the dimensions of the largest example in
my collection, which I obtained some years ago from Mr. G. B. Sowerby. Up to six
lines in length and much less the apophysary system is composed of a large central
longitudinal septum, not exceeding half the length of the valve, arising rapidly in the
form of a narrow elevated plate, almost reaching the centre of the ventral valve, to the
middle of Avhich, and to the base of the hinge-plate, are attached the principal stems of
the riband-shaped lamellre before becoming reflected. Mr. L. Reeve and several other
malacologists have adopted my name Ecansii, but I have had to relinquish it after a very
careful study of a large number of specimens from one and a half up to twenty-two lines
in length. Atone time, as stated by Donovan, Terebratella crnenta, Dillwyn, was a rare
shell, a specimen having fetched five guineas at the Leverian sale ; now, however, it has
become an almost common shell, and may be had for a few shillings.

45. Terebratella Mari.e, A. Adams. (Plate XV. figs. 13, It )

Terebratella MaricB, A. Adams, On some new Genera and Species of ^Mollusca from Japan, Ann. &
Mag. Nat. Hist. 3rd ser. vol. v. p. 413, 1860, and Ann. & Mag. Nat. Hist. Srtl scr. vol. xi. p. 9U, 1863;
Davidson, On Recent Japanese Brachiopoda, Proc. Zool. Soc. 1871, j). 305, pi. xxx. figs. 15-17; Dall,
Proc. Acad. Nat. Sci. Philadelphia, p. 181., 1873; G. Duuker, Index Mollusc, maris Japoniei, p. 252,
1882.

Shell small, somewhat squarely oblong, longer than wide, lateral margins very little
rounded, nearly sub^iarallel, front broad, almost straight. Dorsal valve moderately
convex, with a broad, slightly raised, mesial fold, commencing near the front. Ventral
valve much deeper than tlie opposite one, with a broad, slightly concave dej)ression
commencing at about half the length of the shell, and extending to the front ; beak
short, incurved and truncated by a circular foramen, anteriorly margined by two narrow
deltidial plates. Front margin raised into a rounded wave, lateral margins fiexuous.
Surface smooth, traversed by fine concentric lines of growth ; shell-structure finely
punctate. Length G, breadth 4, depth 3| lines. Colour white, glazed, semitransparent.
In the interior of dorsal valve the loop, twice attached, extends to about two thirds of the

90 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

length of the shell ; mesial septum most elevated anteriorly, extending to within a third
of the length of the valve ; principal stems of the loop attached first to the hase of the
hinge-plate, and then at about a third of their length by a transverse lamella to the upper
edge of the anterior extremity of the septum, when, after extending for some distance,
they become widely reflected, the reflected lamella being much broader than that of
the principal branches.

Sab. Dredged by Mr. A. Adams at Uraga in 21 fathoms; Gotto in 48 fathoms;
and at Satanomosaki in 55 fathoms : all in Japanese waters.

Obn. This pretty little shell was briefly described, but not figured, in 1860 by A. Adams.
It is an imj)ortant species, and nearly approaches in shape and character to the
Upper Pliocene Terebratella septata, described by Philippi in vol. ii. of his work, ' Eauna
Molluscorum E-egni utriusque Sicilise,' p. 69, pi. xvii. fig. 7, 1814, and by Seguenza in
vol. i. Memorie della Soc. Ital. di Scienze Natural!, 1865. Terebratella septata is,
however, a much larger shell than the Japanese Terebratella Maivce, measuring
over an inch in length by ten lines in breadth. The principal branches of the loop
seem to be closer, and the reflected portion broader, than in the two specimens of the
recent shell that I have been able to examine. Dr. Gwyn Jeffreys considered Tere-
bratella MaricB to be the living representative of the Sicilian species ; but this point
cannot be definitely determined until more specimens of the Japanese species have been
examined and compared.

UMcertain Species.

46. Terebratella pulvinata, Gould, sp. (Plate XVI. fig. 15.)

? Terebratula pulvinata, Gould, Proc. Boston Soc. Nat. Hist. vol. iii. p. 347, 1850; U.S. Exploring
Expedition, Shells, p. 467, pi. xliv. figs. 581 a-e.

Terebratula [Waldheimia) pulvinata, Gould, Otia Coucli. pp. 97 & 255, 186.2; Cooper, Geogr. Cat.
California Moll. p. 3, no. 4, 1867.

Terebratella pulvinata. Carpenter, Check-List West Coast N. Amer. Shells, 1860; Dall, Amer. Journ.
Conch, vol. vi. p. 117, 1870.

Terebratula pulvilla, Carpenter, Rep. Brit. Assoc. 1856, p. 213.

Sliell orbicular, about as broad as long, widest posteriorly, tapering anteriorly, sides
and front margins rounded, hinge-line obtusely angular. Dorsal and ventral valves
regularly convex ; beak small, truncated by a circular foramen lying close to the umbo
of the dorsal valve, but slightly separated from it by a small deltidium in two pieces
Colour light yellowish white. Length 10, breadth 10^, deptli 5 lines. In the interior of
the dorsal valve the loop is long and doubly attached, first to the base of the hinge-plate,
then to a mesial septum which extends from under the hinge-plate to about two thirds
of the length of the valve.

Eab. Puget Sound, Oregon.

Obs. I have only seen the figures given of this shell by Dr. Gould, and a photograph
of the type sent to me by Mr. Dall. I feel very uncertain with respect to its
specific value, and have long been under the impression that it might be only one
of the young stages of Waldheimia venosa. Mr. Dall, however, writes to me : —
" Terebratella pulvinata is, I believe, an excellent species. It resembles, externally,
the young flatfish forms of Waldheimia venosa, but it is a perfect and mature Terebratella

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 91

and in no way related to Terehratella dorsata. I may, however, remark that I have
smooth examples of T. dorsata that I could scarcely distinguish from the figures of
Gould's specimen. Gould's types can all he seen in the National Collection at Wash-
ington. Dr. Gould says that the surface of the shell, when examined by the aid of a
lens, is tessellated with elongated dots arranged in quincunx, which seem to he specks of
opaque white coloiu* rather than punctures. T. jndvinata m.ust, however, for the present,
be looked upon as a doubtful so-termed species.

47. Terebratella (?) bubiginosa, Dall. (Plate XVI. fig. 19.)

TerebrateUa ?, Dall, Amcr. Jouru. of Conchology, vol. vi. p. 122, pi. vi. fig. 4, 1870.

Terehratella suffusa, Dall, Amer. Joui-u. of Concliology, vol. vii. p. 65, 1871 (not of Reeve).
TerebrateUa rubiyinosa, Dall, ibid. vol. \'ii. p. 65, and Proc. Acad. Nat. Sci. Philadelphia, 187.3,
p. 185.

Shell almost circular, about as broad as long ; margins fiexuous. Dorsal valve mode-
rately convex, with a faint depression near the middle of the margin, but which is not
noticeable in the younger portions of the valve. Ventral valve convex, rather deeper
than the dorsal one ; beak short, slightly incurved and truncated by an incomplete round
foramen, margined by the umbo of the dorsal valve, and by two very small rudimentary
lateral deltidial plates. In the interior of the dorsal valve the loop is long and doubly
attached, first to the base of the hinge-plate, and then to a short mesial septum. Surface
smooth to within a short distance from the margin, when the valve presents a few irregular
rounded areas. Colour a rather light brown. Length 1 inch 1 line, breadth about the
same.

Hah. ? Cape of Good Hope. (?? Types in the Smithsonian Cabinet.)

Ohs. I am very doubtful with respect to the specific value of this species. In 1870,
Dall referred it with uncertainty to the Terehratella suffusa of Reeve (Conch. Icon. pi. v.
fig. 18), but after my subsequently sending him Reeve's type of T. siffusa for examination,
he wrote back that as Reeve's type is possessed of a lai'ge elevated septum and loop Hke
Magasella, he has given the name Terehratella ruhiginosa to his species. In his de-
scription of the shell he informs us that " the crura are small, slender, short, and acute.
The loop processes are exceedingly slender, mere threads in fact, and roundly deflected
outward at first ; bending inward just before the neural bend, they give off two
moderately broad septal processes, which meet each other at the end of the septum at
an angle of 60° (not at right angles to the septvim and behind its end, as in T. dorsata
or chilensis). The main processes are then deflected neurally, and the extreme
' bight ' of the loop is straight and somewhat angulated at each side. The perforations
externally are moderate, arranged in quincimx order, .smaller and more regular than in
T. dorsata, which is its nearest analogue."

Never having seen any specimen of T. ruhiginosa, I can only reproduce Mr. DaU's
statements upon the subject. He says that the species appears to him to be perfectly
distinct from any other described Terehratella. The loop he figures is certainly very
peculiar in its mode of attachment to the short mesial septum.

SECOXD SERIES. — ZOOLOGY, VOL. IV. 13

92 DK. T. DAVIDSON ON RECENT BRACHIOPODA.

48. Teeebkatella Frielii, Davidson. (Plate XVI. figs. 16-17 h.)

Terehratella Frieli, Davidson, Proc. Royal Soc. xxvii. p. 438, 1878 ; and T. frielii, Report on the
Brachiopoda, Voyage of H.M.S. ' Challenger/ Zool. vol. i. p. 46, pi. iii. figs. 19, 20, 1880.

Shell small, ovate, slightly longer than vfide, smooth, white. Dorsal valve moderately
convex, slightly flattened or depressed anteriorly. Ventral valve deeper than the dorsal
one. Beak short, truncated by an incomplete foramen, laterally margined by two very
short and small deltidial plates. In the interior of the dorsal valve, the loop, which
extends to about two thirds of the length of the valve, is doubly attached, first to the
hinge-plate, and then to a mesial septum. Length 5 lines, width 4 lines, depth 3 lines.

ITab. Two small specimens were dredged off Halifax by the ' Challenger ' Expedition at
a depth of 1340 fathoms ; and two other examples close to the Philippine Islands, in 82 to
102 fathoms.

Obs. 1 feel much uncertainty, as I have stated in my ' Challenger ' Ueport, with respect
to the identification of the two small immature shells above described. I forwarded one
of them to Mr. Dall for examination, and he wrote back that he could not positively
identify it with any of the described species. Dr. Gwyn Jeffreys expressed a similar
opinion, adding that the septum and ccecal tubercles are very peculiar and remarkable,
and that he felt certain that it was an undescribed species of Terehratella. I therefore
give it here, merely for reference purposes.

Subgenus Magasella, Dall, 1870.
To this subgenus six species have been referred, viz. : —

1. Magasella flexuosa, P. King.

2. crenulata, Sowerby.

.3. aleutica, Dall.

The following are uncertain species : —

Magasella pataffonica, Gould.

Icevis, Dall.

MalvincB, d'Orbigny.

4. Magasella Adamsi, Davidson.

5. Gouldi, Dall.

6. Cumingi, Davidson.

Magasella incerta, Davidson.

radiata, Dall.

labradorensis, Sowerby.

I am not, however, satisfied that even all those recorded as species can be definitely
accepted. "We know very little that is satisfactory about Magasella (?) crenulata,
Magasella aleutica, Magasella Adamsi, and Magasella Gouldi, and still less about the
six uncertain species. The material I have been able to collect was scanty and insuf-
ficient, and further investigations will be requisite whenever circumstances permit. It
is therefore at present not possible to determine which are really good species, which
varieties only, or synonyms. Magasella Jlexuosa and M. Cumingi are, however, good
species, and have been carefully studied.

49. Magasella flexuosa. King, sp. (Plate XVII. figs. 1-5.)

Terehratula flexuosa, P. P. King, The Zool. Journ. vol. v. p. 337, 1835.

Terehratella flexuosa, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 367, 1852; Woodward &
Gray, Catalogue of the Brachiopoda in the British Museum, p. 87, 1853.

DR. T. DAVIDSON ON EECENT BEACHIOPODA.. 93

Terebratula rhombea, Philippi, Archiv fiir Naturgesch. Jahrg. xi. Bd. i. p. 59, 1845.

Terebratula flexuosa, G. B. Sowerby, Thes. Concli. i. p. 317, pi. Ixix. figs. 23,24, 1846.

Terebratdla dorsata, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wis-
sensch. Wien, Bd. xxxvii. p. 208, 1859.

Terebratula {Terebratella) stiffusa, L. Reeve, Conch. Icon. pi. v. fig. 18, 1800.

Terebratula {Terebratella) Magellanica, L. Reeve, Coucb. Icon. pi. v. fig. 21, 1860; and Ann. & Mag.
Nat. Hist. 3rd ser. vol. vii. p. 176, 1861.

Magasella flexuosa, Dall, Amcr. Journ. of Conch, vol. vi. p. 135, 1870; and Proc. Acad. Nat. Sci.
Philadelphia, p. 189, 1873 ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challeuger,' Zool.
vol. i. p. 46, pi. iv. fig. 5, 1880.

Shell somewhat subtetragonal, about as broad as long, yellowish or light I'cddish
brown, widest near the hinge-line, tapering anteriorly, lateral and frontal margins
flexiious. Dorsal valve moderately convex, longitudinally depressed mesially from about
half the length of the valve to the front. Ventral valve deeper than the dorsal one,
longitudinally keeled. Beak short, incm'ved and truncated by a rather large incomplete
foramen, completed by a small portion of the umbo of the dorsal valve, and by rather
large lateral slightly-separated deltidia ; l)eak-ridges well defined, leaving a flattened
space or false area between them and the long obtusely angular hinge-hnes. Surface of
both valves ornamented with from thirty to forty radiating diverging angular ribs,
ciu'ving to the lateral margins, straight along the middle, with shorter ribs interpolated.
Shell-structure traversed by small canals. In the interior of the dorsal valve the loop
is doubly attached. Mesial septum large, abruptly elevated at its anterior extremity,
extending from under the hinge-plate to about two thirds of the length of the valve.
The upper edge of the septum commences by presenting a gentle curve iu the shape of
a half-circle, then by an oblique nearly straight line reaches its greatest elevation, and
again assumes an almost straight line, to be followed by an abrupt inward curve until
it reaches near to the bottom of the valve, where it gradually terminates by another
gentle curve. The greatest elevation attained by this vertical plate in a specimen ten
lines in length was four lines. The principal stems of the loop at about two thirds of
their length increase in breath and become fixed to the sides of the septum near the upper
portion of the first slope, and, after proceeding a little further, become reflected,
the anterior portion of the septum being prolonged for some distance in front of them
(PL XVII. fig. 5). The muscular impressions are rather large, and are seen on the
bottom of the dorsal valve on each side of the septum. The ribs observable on the
surface of the valve are reproduced on their interior surface. Length and breadth about
1 inch, depth 6 lines.

Hub. Straits of Magellan, in the vicinity of Port Famine ; Orange Harbour ;
Gulf of Patagonia, near Cape Horn, and not far from the Falkland Islands, iu 1450
fathoms ; Port Stanley, at a depth of 5 to 12 fathoms (' Challenger ' Expedition).
Captain P. P. King, K.N., the first discoverer of the species, states, " this shell was
dredged in the Bay of Port Famine, attached to stones ; it is a common shell in the
Straits."

Ohs. In external shape this shell nearly approaches Terebratella dorsata, Gmelin,
and, indeed, L. Reeve places it among the synonyms of tho last-named species. It differs,

13*

94 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

however, iu being subtetiagonal and tapering more anteriorly, with a less sharply defined
mesial depression or sinus in the dorsal valve, and by its ribs being more angular,
and more especially by its elevated mesial Magasella-sha])ed septum, which is always
observable in the interior of the dorsal valve in its adult condition, while, on the contrary,
in fully-developed examples of Terebt^atella dorsata of similar dimensions the septum
rises but little above the bottom of the valve. The mode of attachment of the loop of
the septum is also different in detail.

In 1845, Philippi described, in the ' Archiv fiir Naturgeschichte,' a Terehratula under
the name of T. rlwmbea, a shell similar in shape and character to Magasella jlexuosa.
The type is in the Royal Zoological Museum of Berlin. Philippi did not figure his
shell, and I am indebted to the kindness of Prof. E. von Martens for the figures I am
able to give of the so-termed species, which I believe to be a full-grown example of
Terehratula Jlexuosa, P. King (PL XVII. figs. 6-8 a). It is also stated to have been
procured from the Straits of Magellan.

Terebratellu Jlexuosa is the type of Ball's subgenus Magasella. He states that " the
punctures [on the surface of the shell] are very large, circular, and under the glass
recall the cells of Polyzoa. The margin of the valves is sharply crenulated from the
extremities of the external plications."

Magasella Jtex'uosa does not seem to attain to the dimensions of Terehratella dorsata.

Under the name Terehratella suffusa,, L. Reeve describes (Monogr. Terehratula, pi. v.
fig. 18) what he admits to be a doubtful sj)ecies partaking of the general character of
Terehratula dorsata. In 1861 Mr. Reeve kindly presented me with his type and the only
specimen of the so-termed species with which he was acquainted. The specimen measures
9 lines in length by 8 in breadth and 5 in depth, and is not symmetrical, one half
being narrower than the other, or, in other words, it is to some extent a malformation.
Mr. Reeve says that it shows no indication whatever of a mesial depression in the
dorsal valve ; but this is a mistake, for in reality there exists a slight depression. In
the interior of the dorsal valve there is a large prominent mesial septum to which the
principal branches of the loop are attached previously to being reflected, exactly as we
find to be the case in Magasella Jl£xuosa, to which species therefore I would refer
Reeve's species (PI. XVII. figs. 14 a, h, 15), No specimen of this size of Terehratella
dorsata presented a similarly shaped and elevated septum. Terehratula snjfusa is
evidently a malformation, and its habitat is not known, but it was in all probability
obtained in the Straits of Magellan.

50. Magasella crenulata, Sowerby, sp. (Plate XVII. figs. 9-11.)

Terehratula crenulata^ G. B. Sowerby, Descriptions of 13 new Species of Brachiopoda, Proc. Zool. Soc.
1846, p. 91 ; and Tlies. Concli. vol. i. p. 358, pi. 71. figs. 96-98, 1846.

Tercbratella crenulata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 368, 1852; E. Suess,
Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wissenscli. Wien, p. 206, 1859.

Magasella crenulata, Woodward & Gray, A Catalogue of tbe Brachiopoda in the British Museum,
p. 98, 1853.

Terehratula {Magas) crenulata, L. Reeve, Conch. Icon. Mon. Terehratula, pi. viii. fig. 32, 1861 ; and
Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 179, 1861.

DE. T. DAVIDSON OX RECENT BEACHIOPODA. 95

Magasella crenulata, Dall, A Revision of the TcrcbratulicUe, Amer. Journ. of Conch, vol. vi. p. 137,
1870; and Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 188.

Shell suborbicular, about as wide as long, margin rounded laterally, subtruncate in front.
Dorsal valve moderately and uniformly convex, without fold or sinus. Ventral valve
rather deeper than the dorsal one ; beak produced, slightly incurved and truncated by a
large complete foramen, separated anteriorly from the hiuge-linc by a deltidium in two
pieces ; beak-ridges sharply defined, leaving between them and the hinge-line a flattened
false area. Marginal line flexuous and slightly sinuated in front. Surface of the valves
often smooth at the beak and umbo, or marked throughout with from twenty to twenty-
two rounded ribs, of which a few are due to the interpolation of shorter ones. In the
interior of the dorsal valve the loop is doubly attached, first to the hinge-plate, secondly
to an elevated mesial septum. Colour light yellowish white. Length 8, breadth 8, depth
4 lines.

Hab. Santa Cruz, Canaries (Cuming).

Obs. This small species still requires further study before being definitely admitted.
The material I have had for examination consisted of only three examples. It is much
more circular than Gould's Magasella patagoiiica, and seems to difi^er likewise from
specimens of Terebratella Oorsata of similar dimensions. The foramen was entire in
the few examples that have come under my observation.

51. Magasella aleutica, Dall. (Plate XVII. figs. 16-17 h)

Magasella aleutica, Dall, Preliminary Descriptions of new Species of Mollusca from the North-west
Coast of America, Proc. California Academy of Sciences, vol. iv. pi. i. fig. 6, 1872; and Proc. Acad. Nat.
Sci. PhUadelphia, 1873, p. 188.

Shell small, ovate, greatest breadth about the middle, tapering posteriorly and
anteriorly, slightly indented in front. Dorsal valve convex, most so near the umbo, with
a very slight longitudinal depression commencing at about the middle of the valve and
extending to the front. Ventral valve not much deeper or more convex than the dorsal
one, margins nearly straight ; beak short, incurved and truncated by an incomplete
foramen, margined anteriorly by the umbo and by two small lateral deltidial plates ; beak-
ridges not sharply defined. Surface smooth, marked only by concentric lines of growth;
salmon-coloured, brighter on the lines of growth, pale on the umbones. Length 6 lines,
breadth 7, depth 3^ lines. Loop doubly attached, very slender, except the lateral arms
of the reflected portion, which are wide ; septum rather broad from behind forward, not
produced above the reflected portion of the loop.

Hub. In the Aleutian Islands, from Akeutan Pass to the Shumagins, attached to the
under surface of rocks at extreme low water in spring-tides (Dall).

Obs. I have two examples of this small species presented to me by Mr. Dall, and in
sending them to me he wrote : — " In regard to Magasella aleutica I am disposed to
consider it an adult species, for very thorough dredgings in the region where it is common
have failed to indicate any other species of which it might be the young. I have seen
young Terebratella frontalis, and they appear to differ specifically from Magasella

96 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

aleutica. T. frontalis has never been found at the Shumagin Islands, where M. ctleutica
abounds. Still all that can be said is hardly decisive, and must be left to individual
judgment to be weighed, and future collectors to prove either way." Mr. Dall observes, in
his description of the shell, that " the animal is rather sluggish, and living specimens
kept in sea-water for several days exhibit no further signs of life than the slight opening
of the valves. The soft parts are of a darker reddish colour, and show through the shell
to some extent, as in Waldheimia venosa. There is some variation in form, some speci-
mens being much broader than others."

52. Magasblla Adamsi, Davidson. (Plate XVII. figs. 18, 19.)

Magasella Adamsi, Davidson, Proc. Zool. Soc. p. 307, pi. xxx. figs. 2.3, 24, 1871 ; Dall, Proc. Acad.
Nat. Sci. Philadelphia, 1873, p. 188 ; G. Dunker, Index Mollusc, maris Japonici, p. 253, 1882.

Shell smaU, nearly circular, as broad as long. Dorsal valve slightly convex, and
marked with about eleven more or less prominent ribs, of which the ventral one, in the
dorsal valve, is both the largest and the most elevated. Ventral valve deeper than the
dorsal one, with about twelve ribs, of which the central ones are both the largest and
most prominent, leaving a rather deep median sulcus between them ; beak truncated
by a rather large incomplete foramen ; deltidium-plates small ; shell-punctures large and
prominent. In the interior of the dorsal valve the loop is doubly attached, first to the
base of the hinge-plate and then to a large prominent septum, extending from under
the umbonal beak to about half the length of the valve. Colour white. Length
9 lines, width 2, depth 1 line.

Sab. Two examples only of this small species were dredged by Mr. A. Adams, in 26
fathoms, in the Sea of Japan, off the island of Kuro-puna.

Obs. In one specimen the ribs were almost obsolete. We know, however, far too little
about this shell to be able to speak in a decided manner with respect to its specific
value. In external appearance it differs from all the known recent forms with which I
am acquainted.

53. Magasella Gouldi, Dall. (Plate XVII. figs. 20-22.)

Mayusella Gouldi, Dall, MS. in Davidson, Japanese Brachiopoda, Proc. Zool. Soc. 1871, p. 307,
pi. xxxi. fig. 11 a,b,c; Dall, Amer. Journ. of Couchology, vol. vii. p. 67, pi. xi. fig. 11, 1871, and
Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 189 ; G. Dunker, Index Mollusc, maris Japonici, p. 253,
1882.

Shell very small, transversely oval, wider than long ; hinge-line nearly as long as the
breadth of the shell ; beak somewhat produced and slightly incurved, with a large
incomplete horseshoe-shaped foramen ; deltidial plates very small and widely separated ;
false area flattened. Ventral valve deep ; dorsal valve slightly convex, with a shallow
longitudinal mesial depression or groove beginning at half the length of the valve
and extending to the front surface of each valve ; marked with about eighteen ribs,
of these, two median ones lie in a kind of sulcus in each valve and extend from the
umbo to the front, while the others are both irregular in width, stouter, and do not
extend to more than half the length of the valve from the margin. The lines of growth

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 97

are well marked. In the interior of the dorsal valve there is no hinge-plate or distinct
cardinal process. The muscular scars are thick and excavated ahove; the septum
and loop are similar to those descrihed in Magasella Adamsi. The shell is yellowish,
with strong rose-colour on the ril)s and towards the edges. Length 2 lines, width
nearly 3 lines.

Ilab. Hakodadi, Japan, on Terehratella coreanica, in GO fathoms (Stimpson).

Obs. I have never seen this shell ; the ahove description was taken from a figure of the
single specimen in the possession of Mr. Dall, which he kindly forwarded to me for
examination, stating at the same time that it agreed with no other described species. It
evidently approaches in character to Magasella Adamsi ; but there are differences between
the two that cannot he cleared away by the inspection of a single specimen. A search
for more examples should be made in the locality where this one was obtained, in order
to determine their real specific value.

54 Magasella Cumingt, Davidson, sp. (Plate XVII. figs. 23-32.)

TerebrateUal Ciiminc/u, Davidson, Ann. & Mag. Nat. Hist. 2nd scv. vol. ix. p. .308, 1852, and Proc.
Zool. Soc. 1852, p. 78, pi. xiv. figs. 10-10.

Magasella Cummyii, Woodward & Gray, Catalogue of the Bracliiopoda m the British Museum,
p. 99, 185.3; Woodward, A Manual of the Mollusca, p. 217, 1856; A. Adams, The Genera of Recent
Mollusca, p. 577, i)l. cxxxi. fig. 1, 1858.

Terebratula {Botichardia) Cumingii, L. Reeve, Conch. Icon., Monogr. of Terebratulu, pi. viii. fig. 30,
1861, and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 179, 1861.

Terebratula [Bouchardia) fibula, L. Reeve, Conch. Icon., Monogr. of Terebratula, pi. viii. fig. 30, 1861,
and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 180, 1861.

Magasella Cumingii, Dall, A Revision of the TerebratulidcTe, Amer. Journ. of Conch, vol. vi. p. 137,
1870, and Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 188 ; Davidson, Report on the Brachiopoda,
Voyage of H.M.S. 'Challenger,' Zool. vol. i. p. 48, 1880; E. Deslongchamps, Etudes critiques sur
des Brachiopodes nouveaux ou peu connus, p. 204, 1884.

Shell very thick, ovato-oblong, marginally rounded laterally and in front, tapering
posterioi'ly. Dorsal valve uniformly convex, or mesially slightly depressed, close to the
front. Ventral valve deeper and more convex than the dorsal one, beak produced,
incurved, and truncated by a small oval-shaped foramen beginning at the summit of the
beak and directing itself on the opposite side to the area. Area triangular, elongated
and excavated, deltidium narrow. Surface smooth, strongly marked with concentric hnes
of groAvth, salmon-coloured with a tinge of red. Shell articulating by means of two
strong teeth in the larger valve and corresponding sockets in the smaller one. Hinge-
plate large, hollowed out, with a narrow longitudinal elevation along the middle,
cardinal process divided along the middle ; a longitudinal mesial elevated triangular-
shaped septum extends from under the hinge-plate to about two thirds of the length of
the dorsal valve, and by a gentle curve reaches and touches the top of the larger
valve near to its anterior portion, whence it descends by an almost perpendicular line to
the bottom of the valve. The calcareous riband-shaped lamellae first proceed from the
socket-walls, directing themselves by a gentle curve to the anterior portion of the septum,
where they become attached ; above these another pair, which are anchor-shaped, are

98 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

fixed close to the sloping portion of the upper edge of the septum, but later unite before
becoming reflected. Length 5 lines, width 4, depth 2J lines.

Hah. This beautiful little species was dredged in large numbers by Mr. John Brazier
at South Eeef, Port Jackson, Heads and Pigs Eock, New South Wales. It was found alive
in the first-named locality, and presented a salmon-red colour. Dead perfectly white
specimens are to be obtained in large numbers. The ' Challenger ' Expedition obtained
it also at Port Jackson in from 2 to 4 fathoms. It is said to have been found also in
Bass's Straits, South Australia {=T. fibula, Eeeve). (See PI. XVII. fig. 33.)

Ohs. When I described this species in 1852, only two dead specimens were known in this
country, and their habitat was uncertain. It is a very remarkable and excellent species,
but its exact generic position has been the theme of some difi'erence of opinion. Mr. L.
Beeve says, in his Revision of the Terebratulidse, Ann. & Mag. Nat. Hist. p. 11, 1861, that
" it is in my opinion neither a Terehratella nor a Magas. It begins to show internally
the caDous thickening both of the valves and of the apophysis of Bouclmrdia tulipa, and
is, above all, distinguished by the acuminated beak and terminal foramen peculiar to that
and to the following species " \_T. fihiduX I quite agree with him in this respect. There
exist also differences between it and McKjasella ; still, for all that, it is to the last-named
genus that the shell bears the strongest affinities, and I am disposed to coincide with
Mr. Dall in placing it in that genus. Magasella Cumingi varies a little, according to age,
in the manner in which its loop is attached to the sides of the mesial septum ; thus in
some specimens the anterior edge of the principal lamellae are fixed to the septum quite
independently of the upperanchor-shaped lamellae, which in those examples have a separate
attachment to the septum (PL XVII. fig. 30) ; again in other specimens the anterior edges
of the principal lamelkie cm've close along the sides of the septum, and become united to
the lower edges of the anchor-shaped pair previous to becoming reflected (PI. XVII.
fig. 31).

In 1861, Mr. Lovell Beeve described and figured, in the paper already referred to, a
shell a little larger, but so similar in shape and character to Magasella Cummgi, by the
name of Terebratula (JSouchardia) fibula, that I am very much disposed to regard it
as nothing more than an unusually large example of M. Cumingi. Mr. Beeve states,
I. c. p. 180, that " This remarkable shell is curiously intermediate in its characters between
T. {Bouchardia) Cumingii and tidipa. The beak is more acuminated than in the former ;
and the area of the deltidium, which in B. Cnmingii and tulipa is excavately grooved, is
in B. fibula flat. In respect of the callous development of the interior, it is about inter-
mediate between the other two."

I may, however, observe that we are acquainted with only one specimen of the so-
termed T. fibula, purchased by the British Museum from Mr. Calvert, a dealer in objects
of natural history. It measm-es 7 lines in length by 6 in breadth, and is consequently
larger than M. Cumingi, which does not seem to exceed 5^ to 6 lines in length where
it is usually found. The area in M. Cumingi is, it is true, usually excavated or concave,
but in some examples it is almost flat, and upon that slight apparent difference it
would not be right, I think, to record it as a separate species. The difference of habitat
may perhaps have been more favovu'able to the development of the single example of

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 99

T. fibula hitherto discovered, whicli is said to have come from Bass's Strait, South
Australia. Those who differ fi-om mc in this identication will find T. fibula dcscril)cd
by Reeve in the following words : —

" Shell orhicularly ovate, solid, smooth, whitish, tinged with rose ; beak large, trian-
gularly acuminated, erect ; foramen small, terminal, deltidium obsolete, area very large,
flat ; valves nearly equally convex, sides callous within ; loop doubly attached, septum
callously anchor-shaped." [Conch. Icon. pi. viii.]

Uncertain Species.

55. ? Magasella patagonica, Gould, sp. (Plate XVII. figs. 12-13 a.)

Terebratula Patagonica, Gould, Proceed. Boston Soc. Nat. Hist. iii. p. 347, 1850, and United States
Exploring Expedition, Mollusca and Shells, p. 97, 1852.

Waldheimia Patagonica, Gould, Otia Conch. (Rectifications) p. 246, Index p. 236.
"i Magas patagonica, Dall, Amer. Jouru. of Coach, vol. vi. p. 133, 1870.
Magasella Patagonica, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 189.

Shell small, subpentagonal, slightly transverse or as wide as long, broadest near the
hinge-line. Dorsal valve very slightly convex, "oith a shallow depression along the middle
of the anterior half of the valve. Ventral valve deeper and more convex than the dorsal
one ; beak short, incurved, and truncated by an incomplete foramen, margined anteriorly
by a small jiortion of the umbo of the dorsal valve and by two small lateral deltidial
plates. Surface of valves smooth at the beak and umbo, the anterior and lateral two
thirds of the length of the valve being ornamented with about seventeen rounded
divaricating ribs of difierent lengths. In the interior the hinge-plate is wide and exca-
vated in the middle. The loop is doubly attached to the base of the hinge-plate, and to an
elevated mesial septum. Shell-punctures prominent and circular. Colour waxen white.
Length 6 lines, width 6, depth 3 lines.

Kab. Orange Harbour, Patagonia (United States Exploring Expedition).

Obs. This appears to be a doubtful species. Mr. Dall writes me that it may be a young
Terehratella dorsata, but he is not certain that it is so. The shell, he adds, is a typical
Magasella (which T. dorsuta is not). Mr. DaU describes the species at considerable length
on pp. 133, 13i of the ' American Journal of Conchology,' 1870 ; he says that the dorsal
valve is provided with an inconspicuous but acute apex, and small, moderately wide
cardinal process. " The hinge-plate is wide and excavated in the middle, or rather
there is no transverse lamina before the cardinal process and between the sockets. Instead,
two thin laminae are placed between the under side of the sockets, extending obliquely
inward for a short distance, and attached to the cavity of the apex, forming a triangular
ridge in the median hne, from which the septum takes its rise. The latter is broad
and biangulate at its nem-al extremity. Two haemal processes, provided witli short
pointed crura, proceed from the sockets and are attached, abovit midway between the
valve and the apex of the septum, to the latter. Erom the posterior apical angle of the
latter two broad, roundly-recurved processes arc extended posteriorly. The anterior

SECOND SERIES. — ZOOLOGY, VOL. IV. 14

100 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

apical angle of the septum is extended a sliort distance in front of tliem, and is somewhat
before the anterior front of the base."

As justly observed by Mr. Dall, this species must not be confounded with the fossU

Waldheimia patagonica, Sowerby, mentioned in Darwin's ' Geological Observations on

South America,' p, 252, pi. ii. figs. 26 & 27, 1846. More material is needed for comparison

before the specific value of this so-termed species can be definitely ascertained. I have

only seen one young example of the shell sent to me by Mr. Dall.

56. ? Magasella (? var.) l.evis, Dall. (Plate XVIII. fig. 4.)

Magasella (? var.) Icevis, Dall, A Revision of the Tcrcbratulidse, Amer. Journ. Couch, vol. vi. p. 136,
1870.

? Terebratula Malvince, d'Orbigny, Voy. Am. Merid. vol. v. p. 674. uo. 779, ix. pi. 85. figs. 27-29, 1847
(according to Dall) .

" Shell perfectly smooth except for the light, but beautifully regular, rounded, con-
centric lines of growth. Outline nearly circular, beak somewhat produced, slightly
recurved, with a large incomplete horse-shoe-shaped foramen. The false area sharply
carinate and separated from the deltidia by a deep groove. The deltidia are short, mode-
rately wide and widely separated. Shell not inflated, of a horn-colour, and conspicuously
punctate. Margin of the valves straight, without any indentation or flexure. Teeth and
sockets slender and weak, the whole texture of the shell being exceedingly delicate and
papyraceous.

The cardinal process is hardly perceptible. The hinge-plate is very thin, excavated,
and covers the posterior end of the mesial ridge which divides the cavity of the beak
below the hinge-plate into two parts. The crura are very short and delicate, the
hsemal processes at first slender, rapidly widen, throwing off a triangular lamina of sheUy
matter from the inner sides which reaches the septum and becomes consolidated with it
between the anterior and posterior edges, so that the posterior edge of the septum forms
a wall between the two triangular lamina3. In the last species \M. jlexuosa] the edge
does not project above the lozenge-shaped plate formed by the two laminae, and in
? Magas patagonica there is only a rounded ridge between them. The septum is broad,
arising close to the hinge-plate, obliquely forward, and is truncate at its extremity, which
touches the opposite valve. The reflected loop is broad and quite circular. The cardinal
muscles are attached in the apical cavity of the neural valve. The peduncle is short and
stout, the other muscles are very slender.

Length "34 in., breadth •32 in., diameter "16 in.

" A single specimen was found adhering by its peduncle to a large specimen of
Waldheimia venosa from Orange Harbor, Patagonia. ? ' Les isles Malouines,' D'Orb.
I.e.

" It is not unlike, in general appearance, a very minute specimen of W. [ Waldheimia']
venosa, except that the foramen is much larger, incomplete and of a different shape. It
may be identical with D'Orbigny 's species, of which the apophyses are not figured, but differs
in its small size and rounded form."

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 101

Obs. I have reproduced Mr. Ball's full description, as I have never seen the specimen
upon which the species (?) has been formed ; but I think its acceptance must be con-
sidered provisional.

57. Magasella. ? Halving, d'Orbigny, sp. (Plate XVIII. fig. 5.)

Terebratulal Malvince, d'Orbigny, Voyage Amerique IMeridionalCj vol. v. p. 674. uo. 779, ix. pi. 85.
figs. 27-29, 1846.

Shell small, ovate or longitudinally oval, broader than long ; valves evenly convex,
without fold or sinus ; beak short, pointed, slightly incurved ; foramen incomplete, mar-
gined anteriorly by a portion of the umbo of the opposite valve and by two lateral small
deltidial plates ; beak-ridges sharply defined, leaving between them and the hinge-line
a flattened space. Shell perforated by minute canals. Interior details not known.
Length 4 lines.

Sab. Obtained during soundings near the Isles Malouines by Dupetit Thouars.

Obs. I have never seen this so-termed species, and it was not to be found at the Jardin
des Plantes. It is in all probability a young and immature shell. It is described here
for the sake of reference, but cannot be admitted as a well made-out species.

58. Magasella incerta, Davidson. (Plate XVIII. figs. 2, 3 a.)

Magasella incerta, Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i.
p. 47, pi. iv. fig. 6 a, b, 1880.

Shell elongated, pear-shaped, broadest anteriorly, tapering posteriorly, very slightly
and evenly convex, somewhat flattened, without fold or sinus, smooth, nearly white. Beak
in ventral valve pointed, nearly straight, with a large incomplete foramen extending from
under the extremity of the beak to the hinge-line, and margined partly by the umbo of
the dorsal valve and by small lateral plates. In the interior of the dorsal valve a short,
elevated, vertical mesial septum almost reaches to the bottom and middle of the opposite
valve ; it extends along the middle portion of the bottom of the dorsal valve to about
haK the length of the shell ; to its sides and to the base of the hinge-plate are attached
the principal stems of the loop, the reflected portion being small. Length 2, breadth 1|,
depth 1 line.

Hah. Twelve examples of this small shell were dredged by the ' Challenger ' Expedition
west of St. Thomas, Danish West Indies, at a depth of 390 fathoms.

Obs. I have reproduced the description and figures of this small species from my
report on the Brachiopoda of the ' Challenger ' Expedition. None of the specimens
exceeded the proportions above given. They look as if they were young and immature
examples of some species at present unknown ; and I have given the shell a provisional
name for reference-purposes. The types are in the Zoological Department of the
British Museum of Natural History.

59. Magasella eadiata, Dall. (Plate XVIII. fig. 1.)

Magasella radiate, Dall; Report on the Brachiopoda of Alaska and adjacent shores of North-west
America, p. 49, 1877.

14*

102 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

Shell small, ovate, longer than wide, hroadest and rounded anteriorly, tapering
posteriorly. Dorsal valve very gently convex, somewhat compressed, with about 16 or
17 rounded radiating ribs of small elevation on both valves, commencing to rise at about
one third the length of the valves, the beak and umbo being smooth. Ventral valve a
little deeper than the dorsal one ; beak slightly incurved and truncated by a large incom-
plete foramen, margined posteriorly by the umbo of the dorsal valve, and laterally by
small deltidial plates. Shell-structure punctate. Colour waxy or ash-grey. Length
3 lines, breadth 2| hues.

Sab. PopoflF Strait, Shumagin Island ; one specimen, with Magasella aleutica, adhering
to stones at the lowest tides (Dall).

Ohs. In 1877 Mr. Dall did not figure his species, but subsequently, in 1885, he sent me
the enlarged figure, wliich I have much pleasure in reproducing, and writes : — " The inside
is like that of the ordinary Magasella form. I did not like to open my only specimen to
get it drawn. I have young Terehratella transversa {^caurina) less than half the size,
which show the imperfectly formed but still genuine Terehratella loop ; hence I cannot
ascribe this to the young state of that species, and as we have no other radiated form in
Alaska yet known, I am at a loss to name an adult form from it."

60. Magasella labkadoeensis, Sowerby, sp. (Plate XVI. figs. 18, 18 a.)

Terebratula Labrador ensis, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 95, and Thes. Concli. i. p. 362,
pi. 71. figs. 89, 90, 1846.

Terebratula {Terebratella) Labradorensis, Sowerby?, L. Reeve, Conch. Icon. Monogr. Ter. pi. v. fig. 19,
1860, and Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 178, 1861.

Terebratella Labradorensis, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 185.

" Shell suborbicular, acuminated behind, obtuse, thickish, whitish ; valves very uueqiial,
obtusely radiately ribbed : marginal line somewhat flexuous ; dorsal valve rounded in
front, acuminated and obtuse behind ; perforations large, entire ; cardinal area large,
somewhat flattened ; deltidia rather large, united ; mesial ridge indistinct ; ventral valve
nearly orbicular, slightly acuminated behind : margin of valves crenulated. — In the
British Museum. Erom Labrador; C. Goodsir." (G. B. Sowerby.)

Obs. I know so little about this doubtful species, that I am obliged to content myself
by reproducing Sowerby's description, in the hope that a search for more specimens
may be effected in the locality whence the shell is said to have been obtained. In the
' Conch. Icon.' LoveU E-eeve figures another species from Cuming's collection, said to
agree with Sowerby's type ; but I cannot help regarding this statement as very uncer-
tain. The sheU is more circular than the specimen figured in the ' Thesaiu'us Conchy-
liorum,' and is stated to be " a rather depressed transparent white orbicular species, of
solid structure, ribbed with more strength and regularity than is common in the genus."
1 have written to gentlemen who have dredged in Canadian waters, but none of them
have ever met with the shell.

DH. T. DAVIDSON ON EECENT BRACHIOPODA. 103

Subfamily MEGEULiNiE.

Genus MEGERLIA, King-, 1850.

This excellent genus was proposed in 1850 by Prof. W. King, at page 145 of Ms
monograpli on the " Permian Fossils of England," published by the Palaiontograpliical
Society, with the following diagnosis : — " A transversely oblong, uni-areagerous Tere-
bratulidia. TJmhone very slightly projecting. Fissure or foramen large, emarginate,
and situated in the centre of the area. Cardinal muscular fulcrum excavated. Zoop
somewhat quadrate ; confined to the posterior half of the shell ; attached posteriorly to
the crural base, and anteriorly to the medio-longitudinal plate. Inner surface of valves
radiately pimpled. Punctures large. Type Anomia trimcata, Gmelin."

We are acquainted with two recognized and one uncertain recent species, viz. : —

Megerlia truncata, Linne, sp., = var. monstruosa, Scacchi.
Megei'lia (?) {Ismenia) sanguinea, Chemnitz, sp.
Megerlia Willemoesi, Davidson. Uncertain species.

As the generic characters have been fully given under Megerlia truncata, they need
not be here repeated.

Mr. Dall, in his Catalogue of the E-ecent Species of the Class Brachiopoda, published in
the Proceedings of the Academy of Natural Sciences of Philadelphia, pp. 186 and 187,
1873, groups the genus Megerlia into two sections : —

Section A (Megerlia). Lateral loops closed; shell transverse, sculptured.

1. Megerlia truncata, Linne.

Section B (Ismenia). Lateral loops open ; shell more or less swollen, ovate, smooth.

2. Megerlia Jeffreysi, Dall.*

3. Megerlia sanguinea, Chemnitz.

The loop, as shown by Prof. E. Deslongchamps, undergoes certain modifications during
its different stages of development. In 1870 Mr. Dall retained the Anomia sanguinea,
Chemnitz, as generically distinct from Megerlia truncata, and placed it in the genus
Ismenia, but in 1873 he regarded it as representing a section of Megerlia.

Section A.

61. Megerllv truncata, Linne, sp. (Plate XIX. figs. 11-20.)

Anomia truncata, Linne, Syst. Nat. ed. duodecima reformata, p. 11.52, 1767; Andrea, Lettres ecrites
de la Suisse, tab. 1. figs, d, e, 1763.

Anomia disculus, Pallas, Misc. Zool. p. 184, t. 14. fig. 1, 1766.

Anomie, fig. b, g, Davila, Cat. Syst. et Raisonne des Curiosites de la Nature, pi. xx. 1867.

Anomia truncata, Chemnitz, Neues syst. Conch.-Cab. vol. viii. p. 90, tab. 77. fig. 701, 1785 ; Born,
Mus. p. 118, tab. 6. fig. 14, 1778; Gmelin, ed. Linne's Syst. Nat. p. 3343, 1788.

* [See page 113 of this monograph, where Dr. Davidson is informed by Mr. Dall that the shell he first named
Frenula Jeffreysi, and afterwards described as Ismenia Jeffreysi, is^ the young of Laqueus californicus, var. van-
touverinds. — A. C]

104 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

Terebratula truncata, Briiguiere, Encycl. Meth. pi. 243. fig. 2, 1789.

Anomia truncata, Poli, Test. Sicil. p. 191, t. 30. figs. 16, 17, 1791-1795.

Terebratula truncata, Retzius, Nov. Gen. Testaceorum, p. 14, 1788.

Terebratula truncata, Dillwyn, A Descriptive Cat. of Recent Shells, p. 293, 1817; Lamarck, An.
sans Vert. vol. vi. p. 247, 1819; Sowerby, Cat. of the Shells of the Earl of Tankerville, p. 28, 1825;
Risso, Europe Mer. vol. iv. p. 387, fig. 174, 1826 ; Blainville, Diet. Sci. Nat. vol. liii. p. 159, 1828, and
= T. disculus on p. 138; Philippi, Enum. Moll. Sicilise, vol. i. p. 95, tab. vi. fig. 12,1834; Von Buch,
Ueber Terebrateln, p. 66, 1834; Scacchi, Cat. Conchyl. Regni Neapolitan!, p. 3, 1836.

Delthyris truncata, Anton, Verzeichniss der Conchylien, p. 22, 1839.

Terebratula truncata, Galvaui, lUust. delle Coq. Fossili, 1845 ; Kiister, Nov. ed. Chemnitz's Conch.-
Cab. p. 28, pi. 3. figs. 11, 12, 1843 ; E. Forbes, Report on the MoUusca of the ^gean Sea, p. 141,
1843; Philippi, En. Moll. Sicili®, vol. ii. p. 69, 1844; G. B. Sowerby, Thes. Conch, p. 354, pi. Ixxi.
figs. 64-67, 1846, and Ann. Sci. Nat. vol. viii. p. m, pl. vii. figs. 11, 12, 16, 37.

Terebratella truncata, A. d'Orbigny, Considerations zoologiques et geologiques sur les BrachiopodeSj
Ann. Sci. Nat. Zool. vol. viii. p. 268, pl. 7. figs. 11, 12, 16, 37, 1847.

Ort/iis oblita, Michelotti, Foss. Mioc. de I'ltalie, pl. i. fig. 21, 1847 ; Sismonda, Synopsis Methodica,
p. 11, 1847.

Orthis truncata, Aradas, Coq. Foss. di Gravitelli, p. 14, 1847.

Megerlia truncata, King, English Permian Foss. p. 140, 1851.

Megathyris oblita, d'Orbigny, Prodrome, p. 134, 1852.

Megerlia truncata, Davidson, Sketch of a Classification of Recent Brach., Ann. & Mag. Nat. Hist.
2nd ser. vol. ix. p. 369, 1852 ; Introduction to vol. i. Brit. Foss. Brach. p. 68. figs. 11, 12, 1853.

Terebratula truncata, Costa, Fauna del Regno di Napoli, p. 33, pl. i. figs. 4-6, 1851.

Megerlia truncata, Woodward and Gray, A Cat. of the Brach. in the Brit. Mus. p. 103, 1856.

Megerlia //-Mwca/a, S. P. Woodward, A Manual of the Mollusca, p. 219, fig. 122, 1856; H. & A.
Adams, Genera of Recent Mollusca, p. 578, pl. cxxx. fig. 3, 1858.

Terebratella truncata and T. oblita, Pictet, Traite de Pal. vol. iv. p. 22, 1857.

Megerlea truncata and M. oblita, E. Suess, Ueber die Wohnsitze der Brach., Sitzungsb. k. Akad.
Wissensch. Wien, Bd. xxxvii. pp. 208, 209, 1859.

Terebratula truncata, Verani, Zool. des Alpes Maritimes, 1862; Risso, Europ. Mer. vol. iv. p. 387,
fig. 174, 1862; Chemnitz, Man. de Conch, vol. ii. p. 205, figs. 1053-1055 (not 1052), 1862.

Megerlea truncata, E.-Deslongchamps, Recherches sur I'Organisation du Manteau chez les Brachio-
podes articules, p. 26, pl. iii. figs. 1-5, 1864.

Morrisia gigantea, Deshayes, Cat, des Mollusques de I'lle de la Reunion (Bourbon), Annexe E, p. 37,
pl. xxxii. figs. 9, 10, 1863.

Megerlia truncata, Seguenza, Pal. Mai. dei Terreni Terz. del distretto di Messina, Mem. Soc. Nat.
di Scienze Nat. vol. i. p. 63, pl. viii. fig. 4, 1865 ; Brusina, Moll. Dalmati, Real. Soc. Zool. Botanica di
Vienna, 1866.

Terebratula [Megerlia') truncata, L. Reeve, Conch. Icon. Monogr. pl. xi. fig. 47, 1861 ; Ann. & Mag.
Nat. Hist. 3rd ser. vol. vii. p. 180, 1861, and Journal de Conchyl. vol. ix. p. 133, 1861.

Megerlea truncata, Weinkaufl", Conchylien des Mettelmeeres, p. 287, 1867; Davidson, On Italian
Tertiary Brach., Geol. Mag. vol. vii. pl. xxi. figs. 1, 2, 1870.

Megerlia truncata, Dall, Amer. Jouru. of Conch, vol. vi. p. 129, fig. 14, 1870, and Proc. Acad. Sci.
Philadelphia, 1873, p. 186 ; Monterosato, Cat. Couch. Med. p. 7, 1875 ; Gwyn Jeffi-eys, On the Mollusca
of the ' Lightning ' and ' Porcupine ' Expeditions, Proc. Zool. Soc. 1878, p. 411 ; Zittel, Handb. der
Palaont. p. 707, fig. 556, 1880; Davidson, Report on the Brachiopoda, Voyage of H.M.S. 'Challenger,'
Zool. vol. i. p. 50, pl. iii. figs. 15-18, 1880 ; E.-Deslongchamps, Etudes critiques sur des Brachiopodes
nouveaux ou peu connus, p. 157, pl. xix. figs. 1 5, 1884.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 105

Shell transversely oval, semicircular or subquadrilateral, somewhat depressed, fulvous
white. Hinge-line nearly straight, nearly as long as the breadth of the shell, with acute
or rounded angles. Dorsal valve gently convex, sometimes much flattened, mesially
depressed longitudinally from the umbo to the front, more or less indented in front.
Ventral valve deeper than the dorsal one, and longitudinally keeled. Beak very little
inciu'ved, and truncated by a large circular incomplete foramen, margined anteriorly by
the umbo and by two small rudimentary lateral plates ; bcak-ridges sharply defined,
leaving between them and the hinge-line a flat area. Surface of valves marked with
numerous fine radiating riblets, increasing in number at variable distances from the
beaks by the interpolation of shorter riblets. Surface of valves crossed by concentiic
Lines of growth. Shell-structure perforated by minute canals. Loop extending to little
more than half the length of the valve, trebly attached, first to the base of the hinge-
plate, then to a short median septum, and again by lateral branches departing from the
reflected upper part of the loop to the upper anterior extremity of the septum. Brachial
or labial appendages consisting of two ear-shaped processes connected by a membrane
forming two large lateral lobes and a short median spiral one. Length 9 lines, breadth
10, depth 6 lines.

Sab. This species was dredged in great profusion by the ' Challenger ' Expedition off
Gomera, Tenerifi'e, in 70 or 75 fathoms. It is a common Mediterranean species, and
abounds on the Atlantic shores. Signer Costa obtained it from near the Island of Capri,
off Ischia, Palmieri, and in the Gulf of Taranto. Prof. E. Porbes states, in his Report on
the Mollusca of the ^gean Sea, 1844, that he found it living at from 60 to 105 fathoms.
It was also dredged off the coast of France, Morbihan, He de Noirmontier; Guetaria,
North Spain, off Marocco and the Canaries ('Talisman' Expedition), in from 50-65 fathoms.
The species has been quoted from New Soutli Wales, but I doubt the accuracy of this
statement, nor have I ever seen any specimens from Japanese waters. The habitat of
the Philippine Islands, given by Woodward, also requires corroboration. The specimen
figui-ed by Deshayes as having been di-edged off the Island of Bourbon (?) certainly belongs
to the species under description ; but it is erroneously named Morrisia gigantea, and its
habitat also requii-es confirmation.

Megerlia truncata is a common fossil in the Upper Tertiary formations of Sicily, Italy,
Nice, and elsewhere.

Ohs. This is an abundant and weU-known species, and the type of the genus Megerlia.
As may be seen from the long list of references, it has been often described, and very
generally so under the specific name of truncata. It bears a somewhat obscure external
resemblance to some forms of Orthis, but, although it has been several times referred to
that genus, it possesses none of its characters. In his admirable memoir entitled
' Recherches sur I'Organisation du Manteauchez les Brachiopodes articules," 1864, M. E.
Deslongchamps describes with minute detail the mantle of several forms, and especially
that of Megerlia truncata. He states that the microscopic flattened spicula of tlie mantle
are still more abundant than in TerebratuUna, have a very peculiar shape, and that the
calcified portions are well defined in both valves. The flattened spicula are wide and
nearly quadi'ilateral, with rounded extremities, the edges being festooned; they form

106

DE, T. DAVIDSON ON EECENT BEACHIOPODA.

Eia

denticulated calcareous plates, and vary suflBciently in arrangement in different genera of
Brachiopoda to serve as distinguishing characteristics (Plate XIX. figs. 18 & 19).

M. E. Deslongchamps describes with much care and detail, at page 117 of his valuable
memoir ' Notes sur les Modifications a apporter a la Classification des Terebratulidte,'
1884, the different stages in the development of Megerlia truncata. He says that
" the modifications the shell undergoes from the embryonic to the adult condition present
a special character, and constitute a rather peculiar type, at least so far as concerns the
brachial appendages. The shell assumes from the commencement a shape which is
but little modified by age. It is only more flattened and nearly circular in the youngest
individuals; ribs obscurely nodulous then mark the surface of the two valves. The
foramen is nearly triangular, but with an elliptic shape. In growing, the shell becomes
more and more transverse and sub quadrilateral, with a slight tendency to indentation in
front. The foramen enlarges posteriorly, but is never provided with more than two
rudimentary deltidial plates even in its most adult condition.

" Rather curious and much more accentuated changes take place in the brachial

appendages. We will examine them first in a shell two millimetres in length The

hinge-plate is very largely developed .... two small
projections, c, indicate the places whence the principal
stems of the loop will afterwards originate, but of which
there is as yet no indication. Towards the middle of
the bottom of the dorsal valve rises an apparatus
very different from that we have hitherto ob-
served, which first develops round the mouth.
Two smaU pillars, P, P, rise from the bottom
of the valve, then expand forward, forming two
thin lamellae, and expand in the shape of two half-
moons, I, I', furnished inside with small irregular
asperities, and miited at their two inner extremities,
leaving free a little triangular space, t. This small
space, to which we wiU apply the name ' escutcheon,'
is completed above by the borders of the semilunar
expansions just mentioned, and there constitutes tlie
deflected lamellae. These are united by a lamella in
the shape of a bridge, P*, which frames the escut-
cheon. The portion of the loop therefore that is first
formed is that in the region of the deflected ajiophysis,
and then no trace of the principal stems of the loop

■ P. I.e.

Young example of Majerlia truncata, 2
millimotres iu length (enlarged), after
M. E. Deslongchamps.

P.l.c, hinge-plate ; c, c, Ist indications of
the principal stems of loops forming two
smaU isolated projections ; P, P, small
pillars rising from the bottom of the
valve, expanding forward in the shape
of two half-moons, Z, l\ furnished with
points ; t, the escutcheon ; P*, united
lamellae in the shape of a bridge.

exists. This is contrary to what takes place in aU
the Brachiopoda we have hitherto recognized. (See woodcut, figure 9.)

" At the dimensions of 4 millimetres these two semilunar expansions, I, I', have become
elongated, and while becoming thinner have lost the small accessory projections of the
first stage. The Y-shaped apophysis that connects the deflected lamellae at the bottom of
the valve forms a process more or less analogous to the pillar of Platydia ; but their

DE. T. DAVIDSON OX EECEXT BEACHIOPODA. 107

development ends tliere, and ;i true median septum is not produced, uniting tlie piilai-
to tlie liinge-plate, as is the case \vitli Zeilleria or Terehratclla proper. The calcareous
appendage or loop oi" tlie genus Megerlia follows therefore, in this respect, the modi-
fications of the Terehralidce proper ; hut the analogy here ceases, for tlie observations
of M. Friele have shown that in these last there exists an entire series of transformations,
I'latkliJ'orm, Muijadifoivn, and TerehnUelliform, bearing no analogy with those of
Mec/erlia."

M. Deslongchamps then explains how in subsequent stages the principal laniellic or
stems of tlie loop become formed, and that this description of the modifications of the
loop must, for the present, l)e restricted to Megerlia trimcata, until those of the other
recent and fossil species referred to the genus have been examined. He states that
there arc four vascular sinuses in the dorsal valve.

M. Deslongchamps observes (Eecherchcs sur I'Organisation du Manteau chez les
Brachiopodes articules, ]>p. 27, 28) that " at the level of the bifurcation of the median
septum the mantle, always lined by tlie pallial apparatus, rises up to join the walls of the
visceral cavity, and thence is reflected throughout the length of the arms. Another part
passes over tlie lower portion of the median septum, covers the branches connecting this
septum to the principal and reflected branches soldered to the brachial appendage and to
the transverse basis which unites them, and afterwards forms one membrane in tlie shape
of an escutcheon, stretched like the skin of a drum between the free internal parts of
these various lamellar apophyses. It there forms the lips of the mouth and of the
interbrachial membrane, and is finally united to the corresponding portion of the mantle
in the large or ventral valve. Throughout this perambulation the mantle is effectually
protected by the pallial apparatus, the spicula of which are almost visible to the naked
eye, except on the different branches of the brachial apparatus where they are absent.
It results from this arrangement that the spicula form on the escutcheon a small area
independent of the rest of the pallial apparatus, and limited in all its circumference by
the laminae of the brachial apjiaratus [Plate XX. figs. 18, 19]. ... In the arms and their
cii'ri the shape of the spicula is entirely different ; they are arranged exactly like those of
the same parts in Terebnttulhia, only their branches are larger and their divisions less
numerous. These S2:)icules have almost the aspect of those on the borders of the
escutcheon, with this difference, that they are always more elongated in the transverse
direction, that is to say perpendicularly to the axis of the length of the canals, and are
much more cut out at their edges."

Dr. Gwyn Jeffreys, in the Ann. & Mag. Nat. Hist, for 1858, ii. pp. 123-4, in referring to
Megerlia triuicata, remarks that " Having examined Dr. Turton's specimen in my cabinet,
which he is said to have procured from Torbay, and which is referred to in the footnote,
p. 3G2, vol. ii. of the ' History of British MoUusca,' I am enabled to state confidently
that it belongs to the above species, and not to Terebratula detruncala or dccollata, as
therein supposed. M. Collard-Descherres records Terebratula truncata as having been
taken on the coast of Finisterrc (Journal de Couchyliologie, tome ii. j). 393), and there is
no reason to doubt the possibility of its being a British species."

Mr. Dall, at p. 130 of his memoir " On a Revision of the Terebratulidte," in the American

SECOND SERIES. — ZOOLOGY, VOL. IV. 15

108 DE. T. DAVIDSON OX EECENT BRACHIOPODA.

Journal of Conch, vol. vi. p. 130, 1870, says that " The [Smithsonian] collection includes
a specimen from New South Wales (coll. Angas), sent under the ahove name \_M. triincatct].
The shell and apophyses presented no constant difference from Mediterranean specimens.
The animal was in a perfect state of preservation in both, and I noticed the following
differences, of which only a much larger series would be sufficient to establish the constancy.
The central spiral lobe of the brachia, prominent in the European species, seemed to be
nearly wanting in the Australian shell. The fringes in the former were nearly twice as
long, the individual filaments much more slender, and five or sis times as numerous
as in the latter."

Megerlia truncata, var. monstruosa, Scacchi. (Plate XIX. figs. 21, 22 «.)

Terehratula monstruosa, Scacclii, Osserv. Zool. no. 2, p. 17, 1838, aud Cat. Coiichyl. Regui Neapolitani,
p. 8, 1836.

Terebrutula monstruosa, Costa, Fauna del Regno di Napoli, p. 43, pi. ix. figs. 4, 5, 1851.
Megerlia truiicata, var. monstruosa, Monterosato, Poche note sulla Conch. Med. p. 4, 1875.

When describing this shell, Scacchi observes that he suspects it might be a malforma-
tion of Terehratula truncata, a view reciprocated by Costa and by several other malaco-
logists, and it is very probable that they are correct in their expression of opinion. Having
had a number of s])ecimens through my hands presenting the same peculiarities, I have
preferred to retain for it the varietal name of monstruosa. In shape it is either circular
or transversely oval, and usually smaller than Megerlia truncata proper. The dorsal
valve is much flattened, and occasionally even somewhat concave and marked with ruts
and irregularities dvie to the olyect upon which it lay closely impressed. There generally
exists at the umbo a semicircular aperture or foramen, somewhat similar to that oiFlati/dla,
which affords passage, in part, to the short thick peduncle. The ventral valve is evenly
convex ; beak very short, with its extremity sometimes i^artly overlying the semicircular
aperture in the umbo of the dorsal valve ; foramen semicircular, completing that in the
dorsal valve. Surface of ventral valve faintly marked by fine radiating raised lines or
I'iblets, that of the dorsal valve with concentric lines. In the interior of the dorsal valve
the loop is exactly similar to that of the typical Megerlia truncata. Colour yellowish.
Length lines, l)readtli 6, depth 2| lines.

Sab. Dredged alive near the Island of Corsica (Scacchi) ; also in the Bay of Naples.

0/js. Were it not for the loop many specimens of this variety or malformation might be
taken for JPlatydice.

Section B.

62. Megerlia sangtjixea, Chemnitz, sp. (Plate XX. figs. 1-8.)

Anomia sanx/vinca, Chemnitz, Neues syst. Conch. -Cabinet, vol. viii. p. 9G, pi. 78. fig. 706, 1785.

Anomia sanguinolenta, Gmelin, ed. Linne's Syst. Nat. p. 3347, 1788; Dillwyn, Cat. of Kecent Shells,
p. 293, 1817 (not of Solandcr).

Terehratula sangulnea, Kiister, Nov. ed. Chemnitz's Conch.-Cab. p. 33, pi. ii. figs. 9, 10, 1843.

Terebrutula cruenta, E. Donovan (not of Dillwyn), The Naturalist's Repository, vol. ii. pi. Ivi. fig. 1^
1824 (according to Donovan tliis is the Anomia cruenta of Solandcr, MS.).

Terehratula sanguinolenta, Blainville, Diet, des Sci. Nat. vol. liii. p. 142, 1828.

DE. T. DAVIDSON OX EECEXT BRACHIOPODA. 109

Terebratula erylhroleuca, Quoy & Gaimard, Voyage de I'Astrolabc, vol. iii. p. j J7, j)l. Ixsxv. figs. 8, 9,
183J?; Deshayes, Nov. cd. Lamarck, Au. sans A^eit. vol. vii. p. 3JU, 18:3(].

Terebratula sanyuinca, G. B. Sowerby, Thes. Couch, vol. i. p. 357, pi. Ixxi. figs. "1-73, 1846.

Terebratula pulchella, G. B. Sowerby, ibid. p. 3G0, pi. Ixxi. figs. 105-107, 18 Ki.

TerehrateUa sanijuiiwa, Davidson, Auu. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 3G8, 1852.

Mvgerl'ia pulchella, Davidson, ibid. p. 369, 1852.

TerehrateUa xanijuhiea. Woodward & Gray, Cat. of Bracli. in Brit. Mus. p. 90, 1853.

Meijerleu yukhella, Woodward & Gray, ibid. p. 90, 1853.

Terebratella sanyuinea, E. Suess, Ueber die Wohnsitze dor Braehiopodcn, Sitzungsb. k. Akad. dcr
Wisscnsch. Wien, Bd. xxxvii. p. 205, 1859.

Terebratula {Terebratella) sanyuineu, lleeve, Conch. Icon. pl. vii. fig. 25 «, Z), c, and Ann. & ISIag. Nat.
Hist. 3rd scr. vol. vii. p. 178, 1861.

Ismenia saiir/uinea, Adams, Ann. & Mag. Nat. Hist. 3rd scr. vol. xi. p. 99, 1863; Dall, .Vmcr. .Jouni.
Conch, vol. vi. p. 127, 1870.

Megerlia sanyuinva, Davidson, Proc. Zool. Soe. 1871, p. 308, pl. xxxi. figs. 1, 2.

Megerlia samjuinea, var. lleevei, Davidson, ibid. 1871, p. 308, pl. xxxi. fig. 3.

Megerlea sanguinea, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 187, 1873; Davidson, Report on the
Brachioijoda, Voyage of II. M.S. 'Challenger,' Zool. vol. i. p. 52, pl. iii. fig. 14, 1880.

Frenulu sanguinea, Zittel, Ilaudbuch der Paliiontologic, p. 708, 1880.

Megerlea sanguinea, G. Dunker, Index [Mollusc, maris Japouici, p. 353, 1882.

Terebratella sanguinea, E. Deslongehamps, Etudes critiques sur des Brachiopodcs nouveaux ou peu
connus, p. 102, jil. xvii. figs. 1-4, 1884.

Shell thin, small, somewhat transversely oval, and quite regular, or almost circular,
as broad as long, smooth, almost polished, with faintly marked concentric lines of
growth. From white or yellow to a livid red, marked with brownish or reddish streaks,
freckled with bright blood-red blotches, bounded on each side by white and yellowish
streaks and patches or spots of red, which radiate towards the margin. Dorsal valve
moderately convex, with a more or less defined mesial dejoression, commencing at about half
the length of the valve and extending to the front. Ventral valve rather deeper than the
dorsal one, uniformly convex, sometimes either slightly keeled or flattened along tlie
middle. Beak moderately incm-ved and truncated by a circular foramen, very slightly
separated from the hinge-line by a small deltidium ; beak-ridges well defined, leaving a
flattened space or area between them and the hinge-line. Shell perforated by canals.
In the interior of the dorsal valve the loop does not extend much further than to about
two tliirds of the length of the valve ; it is three times attached— first to the hinge-plate,
then before attaining half its length to a longitudinal septum, and a third time by
vertical lamina?, which connect the lateral reflected extremities of the loop with the
median septum. Length 7 lines, width 7, depth 3i lines.

Eab. Dredged by the ' Challenger ' Expedition on the reefs of Zamboanga, at 10 fathoms
depth. One example was obtained by the * Astrolabe ' Expedition at Tongatabu. I
have very fine and large examples from off" the Island of Zebu, in the Philippines, and off
Honolulu, in the Sandwich Islands, attached to corals and stones. The Eev. J. Tenisou
Woods sent me specimens of the shell, both white and coloured, from uear Bird's Island,
North Australia. Mr. Adams dredged it at Mino-Sima, in 63 fathoms, and at Gotto in
48 fathoms. It was also obtained by Mr. E. Deplanclie not far from llie coast of
Tahiti, and recently off Phare, jS^ew Caledonia. The variety T. jndchella is stated by

110 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

G. B. Sowerby to liaAe been found by Mv. Cuming attached to corals at Calapan, Isle of
Mindoro, also off the Island of Cocos (Lieut. Swainson). The shell has been dredged
by Mr. J. Brazier oif the Bottle and Glass rocks, Port Jackson, Australia, and at other
places in the same region. (PL XX. figs. 9-11.)

Obs. Mr. E. Donovan, in vol. ii. (1824), of his ' Naturalist's Ptepository,' tells us that
*' this elegant little testaceous body is eminently entitled to the consideration of the
naturalist, being no other than the true Anomia Criienta of Dr. Solander's manuscripts,
preserved in the Banksian library, and of the Portland Museum to which the Solandrian
manuscripts refer ; it is consequently the shell which has been so uniformly mistaken for
and confounded with the Anomia sangiiiuea of the same author, and not unfrequently
with his Anomia rvhicunda also." Such may perhaps be the case ; but as Solander did
not publish a description of his shell, Ave are bound to take the name of the Anomia
sangitinea described and figured by Chemnitz in 1785. To a bleached specimen from
Japan, A. Adams, in 1863, gave the name of Ismenia JReevei (PI. XX. figs. 12, 12 b of this
work), and Mr. L. Eeeve states, in his description of T. sanguinea, that " An examination
of more than a dozen specimens of this charming species, most of them with the soft
parts macerated, so as to afford excellent comparisons of the loops, has convinced me
that Mr. Sowerby's T. ^yvlcheUa {Megerlia irnlcheUa, Davidson) is merely a variety of the
old Anomia sanguinea of Chemnitz." If only Sowerby's figures of T. sanguinea and T.pul-
chella are compared, one might perhaps feel disposed to conclude that they represented
different species ; but when one examines, as I have done, a large number of individuals,
it is soon found otxt that the two extreme forms are connected by intermediate or passage
ones. The red spots on the shell also vary much in extent, and even shaj)e, sometimes
forming a longitudinal and rather wide mesial band with a small yellow band on each side,
on Avhich none are visible, and in some examples short ribs are also observable near the
margin in both valves.

M. E. Deslongchamps, in his paper already referred to (p. 102), classes T. sanguinea with
Terebratella, and describes some of the changes it undergoes from the youngest stage up
to the adult condition. He says " that the brachial apparatus or loop is more comj)licated
than that of true Terehratellce , and very similar to what we observe in the IlegerJiforni
stage of Waldheimia septigera, but with an additional complication." In my opinion
T. sanguinea is not a true Terebratella, and, if not a Megerlia, would require to be left
with Ismenia or some other genus. In plate xvii. of the work just quoted, Deslongchamps
figures the passages of T. sanguinea from the Platydiform into the Magadiform stage at
the dimensions of 4 millimetres, the commencement of the Megerllform stage at 8
millimetres, and the Megerliform stage of the species at the dimensions of 10 millimetres
(see our PI. XX. figs. 4, 5, 6, 7, 8 ; and the corresponding explanations).

Mr. Ball, in his paper in the Amer. Journ. of Conch, vol. vi. p. 128, 1870, when
describing Ismenia sanguinea, mentions that "There is some variation in tlie obliquity
and breadth of the apophyses in different individuals, but the essential characters remain
the same. The punctures in the shell are larger and more conspicuous than in any
species of the group with which I am acquainted. The imbricating prisms of which the
shelly structure is composed are beautifully conspicuous with a very low power, inside;
and even the apojohyses seem to exhibit the same or a similar structure, though impunc-

DE. T. DAYIDSOX ON EECEXT BEACHIOPODA. Ill

tate In general, the foramen is moderate and the (k'ltidia are united, but in many-
cases the foramen is large and the deltidia are more or less widely sejiai'ated, and the a2)ex
is produced. I cannot doubt the identity of T. iJulchella, Sby., Avith T. sangidnca of
Davidson and Chemnitz."

JJncertcdii Species.

03. Megerlia Willemoesi, Davidson. (Plate XIX. tigs. 23-2(5.)
M(>(/erlia Jll/Zemocsi, Davidson, Proc. of the Koyal Soc. vol. xxvii. p. 438, 1878.
Merc/eVut ii-il/cinik'si, Report on the Braeliiopoda, Vojage of H.INI.S. 'Challenger,' Zoology, vol. i. p. 51,

pi. iv. figs. 1-3, 1880 (erroneously labelled on plate Muyasella Willemoesl).

Shell ovate, or longitudinally oval, broadest anteriorly, tapering posteriorlv. Valves
moderately convex, surface smooth, white. Dorsal valve moderately convex, not quite
so deep as the ventral one, and somewhat flattened anteriorly so that the front line is
slightly depressed. Yentral valve very convex, slightly flattened along the middle and
especially so anteriorly. Beak produced, comparatively large and truncated by a circular
foramen, separated from the hinge-line by a rather wide and high deltidium. In the
interior of the dorsal valve tlie loop is three times attached — first to the hinge-plate, ao-ain
to a median si^ptum, and thirdly by perpendicular lamellye which connect the lateral
reflected extremities of the loop with the median septum. Length 7 lines, width 5, depth
4 lines.

Hub. rive examples of this interesting species, attached to branched Polyzoa, were
dredged in company with Terehratula ihva by the 'Challenger' Expedition, off Twofold
Bay, South Australia, or between Sydney and Melbourne, in 120 fathoms.

Ohs. I can add nothing Avith respect to this species to the description here reproduced
from my ' Challenger ' report. The discovery of more specimens would be desirable
before the species is definitely admitted.

Subgenus Laqueus, Dall, 1870.
Type Laqueus californiciis, Koch, sp.
When proposing this subgenus, Mr. Dall published th(> following diagnosis : —
" Shell with the reflected portion of the loop attached by slender processes, on each
side, to the luunial processes, at or near the points where the two septal jn-ocesses branch
off to the septum. Foramen complete. It will be observed that the reflected part of
the loop is attached by the two (lateral) processes, not to the septum nor to tlie septal
processes, but to the hapmal portions of the loop (which I have termed haimal processes) ;
thus the two septal processes, the two lateral processes, and the 'bight' of tlie neural
loop, form a somewhat sinuous ring, intersected by the point of the septum, the lucmal
processes and the two sides of the neural loop." (Eevision of the Terebratulidic, 1870,
p. 123.)

This is a very good subgenus and has been generally accepted. We are acquainted
with tliree recent species and a named variety *, viz. : —

Laqueus californiais, Koeli.

californiciis, var. vancouveriensis, Davidson.

haqums pictus, Chemnitz.
ruhellus, Sowerby.

* \_Laqueus siiffmus, Dall, is figured on PI. XIX. figs. 0, 7 h. It was subsequently placed as a synonym of L. rubcUus,
by Dall, but was considered by Davidson tu be the young of L. ijiciics (p. 114). — A. C]

112 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

64. Laqueus califoknicus, Koch, sp. (Plate XVIII. figs. 6-9.)

Terebratula califonuca, Kocli, Kiister, nov. ed. Chemnitz, Couch. -Cabinet, vol. viii. pi. 2 b. figs. 21-23,
1843.

Terebratula Kochi, Kiister, ibid. vol. viii. pi. 2d. figs. 1-3, 1843.

Terebratula Ca/ifornica, G. B. Sowerby, Thes. Conch, i. p. 352, pi. Ixx. figs. 50-52, 1846.

Terebratula Californiana, Davidson, Sketch of a Classification of Recent Brachiopoda, Ann. & Mag.
Nat. Hist. 2nd ser. vol. i.K. p. 3G4, 1852.

Waldheimia Californica, Woodward & Gray, Cat. of Brach. in Brit. Mus. p. 60, 1853; V. Carpenter,
Rep. Brit. Assoc. 1856, p. 298; Cooper, Geogr. Cat. p. 3. no. 5.

Waldheimia californiana, E. Suess, Ueber die Wohnsitze der Brach. Sitzungsb. k. Akad. der Wissensch.
Wien, Bd. xxxvii. p. 202, 1859.

Terebratula [Waldheimia) globosa, L. Reeve (not of Lamarck), Icon. Conch. Monogr. Ter. pi. ii. fig. 3,
18C0.

Laqueus californicus, Dall, Amer. Jouru. Conch, vol. vi. p. 123, 1870, L. Californica, Proc. Acad. Sci.
Philadelphia, 1873, p. 186 ; E. E. Deslongchani])s, Etudes critiques sur des Brachiopodes nouveaux ou
l^eu connus, p. 202, 1884; Zittel, Handbuch der Palaontologie, p. 706, 1880.

Shell large, longitudinally oval, inflated ; margins slightly sinuous. Dorsal valve uni-
formly convex, with occasionally a very slight tendency to depression close to the frontal
margin. Ventral valve a little deeper than the dorsal one, with sometimes a slight indi-
cation of a mesial longitudinal elevation or flattened fold ; beak incurved, truncated by
a small circular foramen, margined anteriorly by two wide deltidial plates ; beak-ridges
sharply defined, leaving between them and the hinge-line a flattened space. Surface of
valves smooth, with concentric lines of growth, shell-perforations rather large. Colour
livid yellowish brown or light reddish brown. Length 2 inches 6 lines ; breadth 1 inch
11 lines ; depth 1 iucli. In the interior of the dorsal valve the hinge-plate is bifid ; car-
dinal process inconspicuous. The septum, of small elevation, extends from under the
middle of the hinge-plate to a little more than a third of the length of the shell ; the
principal lamella} of the loop, after having been attached to the angles of the hinge-plate
and giving off short curved crura, proceed a short distance, when they again give off two
slightly oblique laminte, which become attached to the anterior edge of the mesial septum.
The principal stems of the loop then extend to witliin a short distance of the frontal
margin, Avhcre they become deflected in the shape of a horse-shoe, giving ofi' on each side
a short lamella near their upper extremity, thus connecting the reflected portion with
the principal stems of the loop close to the point where the two oblique lamellte leave for
their attachment to the mesial septum.

Ilah. Coast of Barbara County, California, in 90 fathoms (Dall).

Ohs. This fine species, little inferior in size to Waldheimia venosa, Solander, has
often been confovmded with it on account of its similarity in external shape. The two
species are, however, perfectly distinct. The small foramen, w^idely separated from the
hinge-plate in Laqueus californicus, at once distinguishes it from IP'uhlheimia venosa,
which possesses a much larger foramen but little separated from the hinge-line. The
absence of a defined cardinal process in the interior of the shell and a very different
arrangement of the loop further distinguish the two species.

The Terebratula Kochi, Kiister, is only a smaller specimen of Laqueus californicus.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 113

Go. LAQUErS CALIFOENICUS, vav. VAXCOTJVERIENSrS. (Plate XYITT. figs. 10-13 Ij.)

Off Vancouver Island we find in large numbers a smaller race or northern form
which Mr. Dall considers to be Laqucus californicus. The shell has also been quoted by-
Mr. J. F. Wliiteaves from off Metla-katla, Queen Charlotte Islands, and from between
Ilacc Island Lighthouse and Victoria lIarl)our, in from 30 to 70 fathoms, as well as ofi' the
N.W. end of Texada Island, in 40 to 70 fathoms, west coast of North America. I have
examined a number of specimens of this shell, some quite circular, others ovate and
truncate anteriorly with a slight depression on the anterior third of tbe lengtli of both
valves. Tlie foramen is also comparatively larger than in typical Californian examples of
LaqHens californicus. Interiorly the loop and its attachments are similar to tliose of the
Californian shell. It is decidedly of a livid yellowish-brown colour. After consulting
with Mr. Dall upon the subject, he wrote me back, on the I7th of December 1884 : — " The
shells from Vancouver which I referred to L. californicus are, I am quite confident, a
northern form of that species, less briglitly coloured, thicker, and ruddier. I have northern
specimens fully as large as the southern ones, and I believe my Mcgerlia Jeff'reijsi to be the
young stage of it. The northern form might perhaps have a varietal name; but if Ave
had plenty of specimens, I think they would be found to intergrade."

I had always felt much uncertainty with respect to tlic specific value of the so-termed
Megevlia Jeffreysi, and was therefore pleased to hear Mr. Dall adniit that it miglit prove
to be a young stage of the northern form of Laqneus californicus. In 1871 it was In-iefly
noticed by Dall in the 'American Naturalist,' vol. v. p. 55, under the name of
Frenula Jeff'rcijsii ; in the same year in tlie ' American Journal of Conch.' vol. vii. p. 65,
pi. ii. figs. 7-10, by the name of Ismenia Jeffreijsl ; and in the ' Proc. Acad. Nat. Sciences
of Philadelphia,' 1873, p. 187, under tlie name of Megerlia Jcffreysi. It was dredged by
Dall at Port Etches, Alaska Territory, in 14 fatlioms chalky mud, as well as alive off the
Semidi Islands. It is also said to have been obtained iu the North Atlantic Ocean ; but
this statement needs confirmation.

G6. Laqueus kubellus, G. B. Soworby, sp. (Plate XIX. figs. 1-5.)

Terebrutula riibvUa, G. B. Sowerby, Proc. Zool. Soc. 184Gj p. 94, ; Tlies. Conch, i. p. 330, pi. Ixix.
figs. 40-12, 1840.

Terehratella rubella, Davidson, A Sketch of a Classification of Recent Bracliiopoda, Ann. & ^lag.
Nat. Hist. 2ud ser. vol. ix. p. 368, 18o2 ; Woodward & Gray, Cat. of Brach. in tlic Brit. ]\Ius. p. 90,
1853 ; L. V. Schrenck, Reiscn imd Forschungen im Amnr-Lande, p. 4GG, 1831-56; E. Sucss, Ueber die
Wohnsitze der Brachiopodcu, Sitzungsb. k. Akad. der Wisscusch. Wien, Bd. xxxvii. p. 205, 1859.

IValdheimia craniutii, A. Adams (not of Miillcr), Recent Brachiopoda I'ound in the Seas of Japan,
Ann. Mag. Nat. Hist. 3rd ser. vol. xi. p. 98, 1863.

? Laqueus siiffiisufi, Dall, Amcr. Jonrn. of Conch, vol. vi. p. 125, pi. vii. tig. h, 1870.

Laqueus rubella, Davidson, Proc. Zool. Soc. 1871, p. 306, pi. xxx. tigs. 18-22; Dall, Proc. Acad. Nat.
Sci. Philadelphia, 1873, p. 186; (>. Danker, Index ^lollusc. maris Japonici, p. 252, 1882.

Shell longitudinally nearly oval or ovate, longer than wide, straight or indented in
front, lateral margins very gently sinuated. Dorsal valve uniformly convex to within a

Ill DE. T. DAVIDSON ON EECENT BEACHIOPODA.

third or fourth of its length, when a flatfish mesial depression, about four lines in brcadtli,
commences and extends to the front. Ventral valve deeper and more convex than the
dorsal valve, keeled along its posterior half, gently depressed mesially along its anterior
half. Beak incurved, truncated by a small circular foramen, margined anteriorly by two
small narrow deltidial plates ; beak-ridges well defined, leaving between them and the
hinge-line a narrow flattened false area. Colour yellowish red, varying in intensity or
more vividly coloured at the concentric lines of growth, and sometimes rayed with
bright red. Length 1 inch 8 lines, breadth 1 inch, depth 7 lines.

In the interior of the dorsal valve the loop is long, the hinge-plate divided along the
middle. Mesial septum, not very prominent, extends from between the hinge-plates to
rather less than half the length of the valve.

The principal lamellse forming the loop after having become attached to the base of
the hinge-plate soon give off a horizontal lamina which attaches itself to the anterior
edge of the mesial septum, and after having attained its greatest length again becomes
reflected, the upper lateral portions of the deflected loop l)ecoming connected to the
principal stems by an oblique lamella, close to the point where the horizontal lamella
leaves for its attachment to the mesial septum.

Hah. Dredged by A. Adams, from a clear stony bottom off the small island of
Kuro-Sima, at a depth of 35 fathoms, Japan; by Prof. R. Plumpelly at the wharf at
Yokohama, Japan ; and by Capt. St. John in the Strait of Corea, in from 23 to 35 fathoms.

Ohs. Since Sowerby described this pretty shell in 1846, many much larger and finer
examples have been obtained from Japanese waters. The shell does not appear to vary
much in shape, and is distinguished from Laqueus 2^ict/(S by its straight or slightly
indented front. In 1870 Dall proposed a new species under the name of Laqueus suffusus
(PL XIX. figs. 6, 7 h), but this he relioquished in 1873, locating his so-termed species as
a synonym of L. ruheUvs ; but I am myself more inclined to regard it as a young
condition of Laqneus jjiclns. In colour L. rnbell as \a.vies considerably, some sjjecimeus
are ashy white, others are of a general salmon-colour, which deepens into orange-red near
the lines of growth or margins of the shell. In some examples, besides a general reddish
tint, a few rays mark the lateral portions of the shell, but these are rarely so strongly
defined as in Sowerby's figure, in which the coloration is exaggerated.

G7. Laqueus pictus, Chemnitz, sp. (Plate XVIII. figs. 14-18.)

Anomia pida, Chemnitz, Concli. -Cabinet, vol. xi. p. 247, pi. 203. figs. 2011, 2012, 1785 ? ; Anton, Yer-
zcicluiiss der Couch, p. 23, 1839.

Terebratula picta, G. B. Sowerby, Thes. Conch, i. p. 351, pi. kx. figs. 43, 44, 1846; Kiister, ed.
Martini & Chemnitz, Conch. -Cabinet, pi. ii e. figs. 8, 9, 1813; Davidson, A Sketch of a Classification
of Eecent Terebmtuhe, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 304, 1852.

fVa/dkeimia picta, Wood\var(i & Gray, Catalogue of Brachiopoda in the Brit. Mus. ]). 59, 1853;
A. Adams, The Genera of Recent Mollusca, p. 575, 1858 ; E. Suess, Ueber die Wohnsitze der Brachiopodcn,
Sitzungsb. k. Akad. der Wisscnsch. Wien, Bd. xxxvii. p. 201, 1859.

Terebraiu/a [IVuldhehiiia) picta, L. Reeve, Conch. Icon., Monogr. Terebratula, pi. iii. figs. 9 «, b, 18G0;
Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 175, I8G0.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 115

Waldheimia p'lcla, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 99, 1863 ; Dal), Amer.
Journ. of Cuucb. vol. vi. p. 112, 1870.

Laqueus pictus, Davidson, Proc. Zool. Soc. 1871, p. 301, pi. xxxi. fig. 10; G. Dunker, Index Moll,
maris Japonici, p. 252, 1882.

Shell ovate, longitudinally oval, broadest about the middle, somewhat acuminated or
rounded anteriorly. Dorsal valve uniformly convex, no fold or sinus. Ventral valve
rather deejier than the dorsal one, beak incurved, slightly overlying tin; mnbo of the dorsal
valve, and truncated by a small circular foramen sHghtly se})arated form the hinge-line
by a deltidium in two pieces ; beak-ridges sharply defiued, leaving between them and the
hinge-line a narrow flattened false area ; marginal line almost straight. Colour yellowish
red, sometimes bright red and marked in an irregular manner with zigzag light-yellowish
ramifying spots. Length 1 inch 4* lines, breadth 1 inch, depth 8 lines.

In the interior of the dorsal valve the hinge-plate is well defined and notched along
the middle ; no distinct cardinal process. A slightly raised mesial septum extends along
the bottom of the valve from the middle of the hinge-i^late to less than half its length ;
the loop is long ; the principal stems, after having become attached to the base of the
hinge-plate, soon give off a horizontal lamella, which become attached to the anterior
edge of the mesial septum, and again extends until it reaches its greatest length, when it
is deflected to form the loop ; before the reflected part has attained its terminations it
gives off on each side an oblique lamella which becomes attached to the principal
stems of the loop, close to the point whence the horizontal lamella leaves for its attach-
ment to the mesial septum.

Hab. Dredged by A. Adams, in 55 fathoms, off Satanomosaki, Japan, and by Capt.
St. John, in 23 and 24 fathoms, in the Corea Strait.

Ohs. This is a fine shell, much sought after by collectors. Its red colour is rarely as
bright as it is sometimes represented to be, the shell being generally of a dull yellow-red
with radially interrupted spots of light yellow. Young sjjecimens tajier considerably
anteriorly, are broader posteriorly, and of a salmon-colour. L. pictus has been successively
placed in the genera Terebratula, Terebratella, and Waldheimia ; but I Avas at last able
to ascertain that its loop was positively that of a Laqueus. L. Reeve gives Terebratula
erythroleuca, Quoy, as a synonym of the species under description ; but this is a mistake,
for it is really a synonym of the Anomia sanguinea of Chemnitz. He also quotes Java
as the habitat of Laqueus pictus, but I have never seen any specimen from that locality.

Subfamily MAGASlNiE.

Genus BOUCHARDIA, Davidson, 1849.

Of tliis genus only one species has hitherto been discovered ; its generic characters
have been described under Bouchardia rosea and need not be repeated here.

68. Bouchardia rosea, Mawe, sp. (Plate XX. figs. 13-18.)

Anomia rosea, Mawe, Intr. to Conch, tab. iv. fig. -l-, 1823.
SECOND SEBIES. — ZOOLOGY, VOL. IV. 16

116 DK. T. DAVIDSON ON RECENT BEACHIOPODA.

Terehratula rosea, G. B. Sowcrby, Cat. of Shells of the late Earl of Tankerville, p. 28, 1825.

Terehratula tulipa, Blaiuville, Diet. So. Nat. liii. p. 144, 1828.

Terehratula rosea, Sander Rang, Manuel de THistoire naturelle des Mollusques, pi. 8. figs. 1-3,
18.29; Deshayes, ed. Lamarek, An. sans Vert. vol. vii. p. 350, 1836.

Terehratula unguis, Kiister, ed. Martini & Chemnitz, Conch. -Cab. p. 35, pi. 2 b. figs. 8-10, 1843.

Terehratula rosea, d'Orbigny, Voyage dans I'Amerique Meridionale, vol. v. p. G74, 1847.

Bouchardia rosea, Davidson, Bull. Soc. Geol. de France, 2" sir. vol. vii. p. 62, pi. i. figs. 1-6, 1849 ;
Classification of Recent Brachiopoda, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 372, 1852.

Pachyrhynchus roseus. King, A Monograph of English Permian Fossils, Pal. Soc. p. 70, 1850.

Bouchardia tulipa, Woodward & Gray, Catalogue of the Brach. in the Brit. Mus. p. 100, 1853;
S. W^oodward, A Manual of the MoUusca, p. 218, 1856.

Terehratula rosea, Hanley, Recent Shells, p. 322, 1856.

Terehratula (Bouchardia) tulipa, L. Reeve, Conch. Icon. pi. mi. fig. 33, 1861.

Bouchardia tulipa, Adams, The Genei'a of Recent Mollusca, vol. ii. p. 577, 1858 ; E. Sucss, Ueber
die W^ohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch. W^ien, Bd. xxxvii. p. 210, 1859;
Dall, Eevision of the Terebratulidse, Amer. Journ. of Conch, vol. vi. p. 141, 1870.

Bouchardia rosea, Dall, Proc. Acad. Nat. vSci. Philadelphia, 1873, p. 191.

Shell thick, with a nearly straight heak, longitudinally oval or spindle-shaped, longer
than wide ; surface smooth, marked here and there with concentric lines of growth.
Colour yellowish red, pink throughout or sparingly rayed with bright crimson. Length
9 lines, breadth 5i liaes, depth 4 lines. Dorsal valve very gently and uniformly convex
posteriorly, anteriorly more or less depressed along the middle. Ventral valve slightly
deeper than the dorsal one, longitudinally keeled ; beak triangularly acuminated, almost
erect, very little incurved, and truncated by a small terminal circular foramen widely
separated from the hinge-line by a concave false area, with two narrow grooves along the
middle ; deltidium blended with the shell. Interior of the valves much thickened
posteriorly. The interior of the dorsal valve is unusually thickened posteriorly, to about
one third of its length ; hinge-plate large and solid, provided with V-shaped diverging
grooved ridges, and much elevated above the other portions of the shell, especially
anteriorly. These long scooped-out ridges probably served for the attachment of the
cardinal muscles. On each side, on a lower level, are the lateral portions of the hinge-
plate, and close to the hinge-line on each side the dental sockets. No cavity exists under
the hinge-plate, which is massive ; but from its sunken base a mesial septum of about one
third the length of the valve extends, this gradually rises until it becomes abruptly
elevated anteriorly in the shape of a wide perj^endicular plate, and to the posterior laljial
slopes of which are fixed anchor-shaped disconnected curved lamellae, broad at their
attachment to the sides of the septum and gradually tapering to a point At the bottom
of the valve on each side of the septum are faintly impressed muscular scars. In the
interior of the ventral valve the shell is much thickened at and near to the beak, as well
as longitudinally ; along its centre extends a wide sliglitly raised ridge with two oval-
shaped muscular impressions on each side ; two deviating massive ridges, deeply excavated
along the middle, extend from under the beak to about one third of the posterior length
of the valve. Teeth for the interlocking of valves strong. The positions of the occlusorj

DE. T. DAVIDSON ON KECENT BRACHIOPODA. 117

divaricator, and ventral adjusters in the ventral valve have been well defined by Wood-
ward, at page 218, fig. 118, of his 'Manual of the MoUusea.'

Hah. Rio de Janeiro, 13 fathoms (Macgillivray) ; bleached dead shells can be picked up
on the beach on the open coast just outside the mouth of the Bay of Rio, but generally
much worn and imperfect (Derby).

Ohs. The animal of this beautiful small species has not been hitherto examined. The
shell varies very little in shape and character ; its internal details are difiicidt to describe
in words, but a glance at the figures will make all clear. The shell has been described
under the specific names of Terehratula rosea, T. tulijM, T. unyuls, and, I believe, T. ttdipa
rosea. Some uncertainty has also prevailed with respect to the name first published.

The form was well figured in 1823 by Mawe under the appropriate specific name of
rosea, some years before that of tuUpa, given to it by Blainville in 1828. Mawe
appears to have adopted names chiefly from the manuscripts of Ilumphrey, Da Costa,
and Solander, and several authors have taken the name rosea from Humphrey.

In 1849, noticing the great dissimilarities the species presented in its internal structure
from other Terebratulida^, I proposed to create a distinct genus for its reception, and gave
it the name of Bouchardia, which has been very generally adopted since that period.
Lovell Reeve, in his monograph on Terehratula, expresses himself to the efi'ect that
T. Cnmhiffi, T. fihda, and T. rosea are distinguished from all other Terebratulae by the
structure of the beak of the shell.

At my request INIr. John Yomig, of the Hvinterian Museum, Glasgow, carefully
examined the shell-structure of Bouchardia rosea and Magasella Cumingi ; he wrote me
on the 20th of April, 1885 :—

" I have carefully etched the valves of both sj)ecies, so as to reveal more clearly the
nature of these perforations. Both species have their shell-structure perforated after the
same manner ; but there are some differences in the perforations and in th(> shell-structure
between the pores, which I will notice further on. Before etching, I examined both the
outer and inner surface of the valves, to see what was revealed, and noted what I saw.
In Bouchardia rosea the outer surface showed numerous minute oval punctures. The
inner surface showed only punctures on the thinner portions of the valve near the margin,
more towards the beak.

" In Macjasella Cnm/i/r/l the outer surface on both valves showed numerous minute oval
pores. These were most distinctly seen around the margin of the valves. On the inner
surface of the ventral valve the punctures are only faintly seen. On the inner surface of
the dorsal valve the punctures are not visible except by transmitted light ; they can be seen
passing downward through the shell-structure. After etching the shells to a greater trans-
parency the perforations become much more distinctly seen on the outer surfaces of both the
valves. In Bouchardia rosea they appear to be smaller and a little more numerous than
in M. Cmninffi. The tubes in their upward passage through the structure of the shell are
seen to be always inclined and directed towards the beak, and these tubes increase in
diameter as they open on the surface, agreeing in this resjject with what has been already
recorded. With a 1-inch or i-inch power of the microscope, imder a strong beam of

16*

118 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

transmitted liglit, the inwardly inclined tubes are very distinctly visible, especially on that
portion of the shell nearest the beak. The tubes are more depressed in £. rosea than in 31.
Cimingi. Another distinction which I notice between the two shells is that B. rosea, when
examined under a hig-her power of the microscope by transmitted light, shows a more dis-
tinctly marked imbricated structure than is seen in M. Cumingi. In the latter species the
prismatic structure is seen to be bent around the tubes in a manner not observable in the
former. I have noticed this bending of the prismatic structure around the tubes both in
Froductm and Chonetes. The real appearance of the perforations as they are seen on the
surface of the shell appears to be due to the angle at which the round tubes reach the
surface, — the more slanting the tubes within the shell the more oval will be the openings
of the perforations. Another point I notice in connection with these perforations
is, that from the middle of the valve, on each side, the tubes or canals incline outward
and upward towards the beak, and where there is a tendency to any folding of the
shell the tubes diverge on each side of the fold."

Subfamily Kraussinin^.

Genus KRAUSSINA, Davidson, 1859.
In 1852, while examining the interior of the valves of Terebratula rubra, Pallas, I was
struck with the marked differences and peculiarities they presented, and in vol. ix. 2nd
ser. of the 'Annals and Magazine of Natural History' I proposed a genus Kraussia,
subsequently (1861) altered to Kramsina, for the reception of T. rubra and four recent
species. The shells are subcircular, with a nearly straight hinge-liue ; beak truncated ;
foramen large and round ; deltidial plates small, not united ; beak-ridges well defined,
leaving a flattened space or false area between them and the hinge-line. In the interior
of the dorsal valve there are two wide, eye-shaped muscular impressions close to the hinge-
line, with a small cardinal process between them. A mesial septum of small elevation
extends to half the length of the valve, from the anterior extremity of which rise t\^"o
oblique or deviating lamellse, laterally expanded ; no other apophysary system for the
support of the labial appendages is present. The ciliated arms are unusually small, their
fringes not extending to more than halfway towards the border of the shell ; in the first
part of their course, from the mouth forwards, the cirri are few or wanting, the whole
brachial apparatus being supported by the small forked process above described, no other
part of the apophysary system being calcified. This genus has been generally adopted.
I have included in it Kruussma rubra, Pallas, K. cognata, Sowerby, K. Deshayesi,
Davidson, K. pismn, Lamarck, K. Lamarckiana ^ Davidson, K. JDavklsoni, Velain, and K.
Atkinsoiri, Tenison-Woods.

In 1884 Prof. E. Deslongchamps (Etudes critiques sur des Brachiopodes nouveaux
ou peu connus, pp. 120-124) proposed to remove the last two species from Kraussina
proper, and to jolace them in a small subgenus Megerliua, on accoimt of two additional
short, projecting, curved, rudimentary lamellte attached to each side of the septum, under
the central deviating forked lamella3 characteristic of Kmusslim. Full details having
been given in the description of the species, it will not be necessary to repeat them here.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 119

A glance at the figiu-cs will likewise assist in understanding the characters often hetter
than verbal description.

69. Kratjssina etjbra, Pallas, sp. (Plate XX. figs. 19-23.)

Anomia Rubicunda, Solander, MS. (accordiug to Donovan, Naturahst's Repository, ii. pi. Ivi., not of
Sowerby) .

Anomia rubra, Pallas, IMisc. Zool. p. 183, pi. xiv. figs. 2-11, 1766.

Anomia striata promontorii bona: spei, Chemnitz, Ncucs systematisehes Conchylien-Cabinet, vol. viii.
p. 94, tab. Ixx^-ii. fig. 103 b, c, 178.5.

Anomia capensis, Gmclin, ed. Linne's Syst. Nat. vol. i. p. .3347, 1788.

Terebratula capensis, Bruguiere, Encycl. Meth. pi. 243. figs. 4-9, 1789; Dillwyn, A Dcser. Cat. of
Recent Shells, p. 292, 1817.

Terebratula ruhicunda, Donovan (not of Sowerby), The Naturalist's Repository, vol. ii. pi. Ivi. figs. 2,
3,4,1824.

Terebratula rubra, Blainville, Diet. Sci. Nat. vol. liii. p. 138, 1828.

Terebratula capensis, Kiister, Martini & Chemnitz, Coneh.-Cab. p. 32, pi. 3. figs. 15-17, 1813; Krauss,
Siidafr. Moll. p. 32, pi. ii. fig. 10, 1848 (not T. capensis, Adams & Reeve, Voy. H.IM.S. ' Samarang,'
p. 71, pi. xxi. fig. 4, 1850).

Kraiissia rubra, Davidson, Sketch of a Classification of the Recent Brachiopoda, Ann. & Mag. Nat.
Hist. 2nd ser. vol. ix. p. 370, 1852 ; Woodward & Gray, Cat. of the Brachiopoda iu the Brit. Mus.
p. 109, 1853; Davidson, Brit. Foss. Brach. vol. i. Introduction, p. 09, pi. vi. fig. 28, 1853; Woodward,
A Manual of Mollusca, p. 219, 1856.

Kraussina rubra, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch.
Wien, Bd. xxvii. p. 210, 1859 ; Davidson, Ann. & Mag. Nat. Hist. 3rd ser. vol. viii. p. 39, 1861.

Terebratula {Kraussia) rubra. Reeve, Conch. Icon., Monogr. Tereb. pi. ix. fig. 37, 1861, and Ann. &
Mag. Nat. Hist. 3rd ser. vol. vii. p. 181, 1861.

Kraussia rubra, Chem. Man. de Conchyl. vol. ii. p. 2056, 1862.

Kraussina rubra, Dall, Amer. Journ. of Conch, vol. vi. p. 138, 1870 ; Proc. Acad. Nat. Sci. Phila-
delphia, p. 190, 1873; Zittel, Handbuch der Palaontologie, p. 708, 1880; E. E. Deslongchamps,
fitudes critiques sur des Brachiopodes nouveaux ou peu connus, pp. 121, 259, pi. xix. fig. 7, 1884.

Shell subch-cular, either as broad as long or a little broader than long ; hinge-line
nearly straight, rather shorter than the breadth of the shell, with rounded corners.
Dorsal valve semicii'cnlar, uniformly convex, with or without an extremely slight
depression near the front. Ventral valve deeper and more convex than the dorsal
one; beak slightly incurved, and truncated by a very large, incomplete foramen,
margined anteriorly by the umbo of the opposite valve, and by two very small deltidial
plates ; beak-ridges sharply defined, leaving between them and the hinge-line a flattened
false area. External surface of valves marked with numerous radiating ribs, increasing
in number by bifurcation and by the interpolation of shorter ones. Surface of valves
crossed by concentric lines of growth. Shell-structui'e punctate. Colour yellowish red,
more intense coral- red mainly on the radiating riljs and at the concentric lines of
growth. Length 1 inch, breadth 1 inch 1 line, depth 7 lines.

In the interior of the dorsal valve the hinge-plate is widely divided, and between the
lateral portions are two large eye-shaped depressions due to the peduncle-muscles ; between
these last a slightly raised mesial septum begins, and extends to about half the length of

120 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

the valve. Prom its anterior extremity arise two short, deviating, flattened and forked
lamellae, expanded at their extremities. The cirrated labial appendages are unusually
small, the spiral lobe diminutive ; these fringes do not extend to more than halfway
towards the border of the shell. In the first part of thek com-se, from the mouth forward,
the cirri are few or wanting, the whole brachial apparatus being supported by the small
forked process above described, no other part of the apophysary system being calcified.
Cardinal process very small. Margin internally, sometimes sharply, spinously toothed.

Mah. Port Elizabeth, near the Cape of Good Hope, South Africa. Some small speci-
mens were erroneously described by Dr. J. E. Gray, in the ' Annals and Magazine of
Natural History ' for 1872, under the mistaken name of T. tnmcata. They were found
attached to Ascidia, and to the stems of large Alga?, off^ the coast of Natal.

Obs. Donovan states, in his ' Naturalist's depository ' for 182i, that Solander had
given the MS. name of T. rubicunda to examples of the shell under description in the
Portland Museum ; but as manuscript names cannot claim priority over published ones,
that of rubra, Pallas, must be adopted. It is also somewhat singular, as observed
by Lovell Reeve, that the shell was not known to Valenciennes when preparing his
monograph of the Terebratulidse for Lamarck's ' Animaux sans Vertebres,' or to
G. B. Sowerby when publishing his ' Thesaurus Conchyliorum ;' for therein he figures a
specimen of T. cruenta with the mistaken name of T. rubra, Pallas. Reeve states
likewise that Sowerby's Terebratula algoensis is a blackened fragmentary valve of
Kraussina rubra. Krauss, on the contrary, says, in ' Die siidafrikanischen MoUusken,'
p. 32, that he looks upon T. algoensis as a synonym of his Terebratula natalensis —
the Kraussina pisum of Lamarck ; and this view may perhaps be the more correct one.
The specimen, which consists of a single ventral valve, is in the Zoological Department
of the British Museum.

In his ' Rechcrchcs sur I'Organisation du Manteau chez les Brachiopodes Articules,'
Caen, 1864, M. E. Deslongchamps' observations (p. 25) are to the effect that the vascular
sinuses are composed of two large trunks, which commence close to the hinge-plate, and
extend by a large curve parallel to the edges of the valves, and end anteriorly close to the
median line, each of these branches, on the sides facing the lateral edges of the valves,
giving forth six or seven branches, which bifurcate as they reach the edges of the shell.
The spicula are very numerous in Kraussina rubra, but they are so small and disunited
that they cannot be seen, except under an enlargement of about 40 or 60 diameters.
At p. 121 of his 'Etudes critiques sur des Brachiopodes nouveaux,' 1884, the same
authority states that he has been able to convince himself that in this species (K. rubra)
the mantle was furnished with spicula of a very special shape, and much smaller than in
the other Brachiopoda provided with these calcareous elements ; that, thanks to the tenuity
of these spicules and to their elongate shape, he has been able, from investigating them
in the genus Kruussina, to recognize their function, which is that of protecting the organs
of circulation. One system of spicula was destined to protect the venous sinuses of
the mantle, a second that of the arterial organs.

M. Deslongchamps further states that he has only been able to examine adult

DR. T. DAVIDSON OX RECENT BRACHIOPODA. 121

examples of Kyaussina rubra, and consequently can say nothing with respect to the
modifications through which the young shell passes previous to attaining its fullest
development, but that the disposition of this appendage in young K. Davidsoni establishes
points of transition so complete between the genera 3Iefferlia and K^^missina tliat there
is not the slightest doubt in his mind as to the position of these genera in the zoological
series, and that they certainly belong to one group. The analogy becomes apparent
when the details of the adult Kranss'ma Lamarckiana and the transitory state of Megerlla
trimcata are considered.

I have never seen any very young examples of K. rubra ; the smallest I have examined
measured 4 lines in length, the largest 12, and no material difference could be perceived
in tbe forked deviating lamellae. I do not see that 3Icgerlia trnncata and Kraussina
rubra are more nearly related than are Terebratella, Laquens, and several others.
We must value the characters of the genus or subgenus and species from the adult and
full-grown condition, and not from that of the early stages of growth ; for many
specimens prior to attaining their adult condition and characters pass through several
metamorphoses or modifications in shape, as has been so admirably demonstrated by
Herman Eriele, E. Deslongchamps, and others. There are also notable differences
between Megerlia and Kraussina in the shape of the hinge-plate, muscular scars, and
labial appendages, which must be taken into consideration.

70. Kraussina cognata, Sowerby*, sp. (Plate XX. figs. 24-26, var. ? 27-30.)

Terebratula cognata, Sowerby (not of Chemnitz) , Thes. Conch, i. p. 346, pi. 68. figs. 12-1 1, 1846.
Kraussia cognata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. i.x. p. 370, 1852.
Terebratula {Kraussia) cognata, L. Reeve, Conch. Icon. pi. is. fig. 38, o, 6, 1861.
Kraussina cognata, Dall, Amer. Joum. of Conch, vi. p. 140, 1870.

Shell somewhat sulitrapezoidal or elongated, semicircular ; hinge-line nearly straight,
almost as long as the width of the shell, with slightly rounded or angular extremities.
Dorsal valve semicircular, rounded in front, with or without a slight longitudinal median
depression along the anterior half of the valve. Ventral valve deep, and much more
convex than the dorsal one. Beak short, very little incurved, foramen large and incom-
plete, margined anteriorly by the umbo of the dorsal valve, and by two small lateral
deltidial plates ; beak-ridges sharply defined, leaving between them and the hinge-line
a triangular area. Surface of the valves radially marked by fine radiating ribs, increasing
in number at various distances from the beak and umbo by the interpolation of shorter
riblets, which are more sharply defined in some specimens than in others. Colour

* [No one can tell from Chemnitz's description and figures what reaUy constitutes his Cocjnata Anomue craniohris
basi perforata (Neues syst. Conchylien-Cabinet, vol. viii. p. 78, tab. 76. fig. 088 a, b, 1785). That author's unsatis-
factory description and illustrations in no way resemble those of the specimen described and figured by G. B. Sowerby
in his 'Thesaurus Conchyhorum ' (vol. i. p. 346, pi. 68. figs. 12-14, 1846). The Anomia cognata of Sowerby (not
of Chemnitz) is now in the British Museum. Chemnitz's figure represents a smooth shell, ovate in form, and with a
rounded hinge-lino. Sowerby 's T. lorjnata is squarely suborbicular, with a long, nearly straight, hinge-line, the
external surface being covered with numerous small radiating ribs. Chemnitz's species is unidentifiable and should
therefore be expunged, and the TerehraUda mrjnata, Sowerby, retained as the type of the species. — T. D.]

122 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

pale yellow. Two specimens measured — length 11 lines, breadth 8 lines ; length
9 lines, breadth 8 lines, depth 4 lines.

In the interior of the dorsal valve the hinge-plate is widely divided, and between the
lateral portions are two large eye-shaped depressions left by the peduncle-muscles,
between which a slightly raised mesial septum begins and extends to about half the
length of the valve. From its anterior extremity arise low, short, deviating, flattened,
and forked lamellae expanded at then* extremities.

Hab. South Africa, near the Cape of Good Hope.

Ohs. This species is distinguished from Krcmssina rubra by its general shape, the
flatness of its dorsal valve, and its colour. In some specimens, such as in Sowerby's type,
the ribs are very little marked and obliterated near the margin, but in others they are
sharply defined ; the mesial depression is, at times, also scarcely perceptible. Both
K. cognata and K. rubra are, however, much more nearly related to each other than to
other species of the genus. Mr. Lovell Reeve alludes to the spine-like projections
round the inner margin of Kraussina cognata, a character common to several, if not
all, the species of the genus. I have noticed them in Kraussina rubra as well as in
K. Lamarckiana. At one time I was under the impression that the Terebratula cognata
of Sowerby might be an unusually large specimen of Kraussina pisum, but I am now
very doubtful whether such is the case.

71. Kraussina Deshayesi, Davidson. (Plate XX. figs. 31-31 b.)

Terebratula capensis, Adams & Reeve (uot of Gmelin), Voyage of H.M.S. ' Samarang,' p. 71, pi. xxi.
fig. 4, 1850.

Kraussia Desliayesii, Davidson, Proc. Zool. See. p. 6, pi. xiv. figs. 20, 21, 1852 ; and Ann. & Mag. Nat.
Hist. vol. ix. p. 270, 1852; Woodward & Gray, Cat. of the Brachiopoda in the Brit. Mus. p. Ill, 1853;
E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. der Wissensch. Wien, Bd. xxxvii.
p. 211, 1859.

Terebratula {Kraussia) Desliayesii, L. Reeve, Conch. Icon. Monogr. of Tereb. pi. ix. fig. 35, 18G1.

Kraussina capensis, Adams & Reeve (not of Gmelin), Dall, Amer. Journ. of Couch, vol. vi. p. 140, 1870.

Shell orbicular, subovate, about as long as wide, valves nearly equally deep or convex.
In the dorsal valve a deep longitudinal depression or sinus extends from the umbo to the
front, with a corresponding elevation or fold in the ventral one ; beak short, incurved,
and truncated by an incomplete foramen, margined anteriorly by the umbo of the dorsal
valve and by two small lateral deltidial plates; beak-ridges sharply marked, leaving
between them and the hinge-line a flattened space. Surface of valves marked with
numerous fine radiating riblets, increasing in number by the interpolation of shorter ones,
the whole surface of the valves being crossed by concentric lines of growth. Shell-structure
largely punctate. In the interior of the dorsal valve two deviating central lamella? rise
from the anterior extremity of the very slightly raised mesial septum. Colour light
yellow, marked with crimson rays. Length 5J lines, breadth 5 lines, depth 2 lines.

Bah. Dredged by Sir Edward Belcher ofi" the Cape of Good Hope, in a depth of
120 fathoms.

DR. T. DAVIDSON ON EECEXT BRACHIOPODA. 123

Obs. This pretty little species is nearly related to KraiisHina pimm, but is distinguish-
able from it by its more orbicular shape and crimson rays. The Kraussina capensis
(Gmelin) being a synonym of K. rubra, Pallas, I proposed in 1852 to alter its name
to K. Deshayesi. I regret not being able to agree with Mr. Ball's suggestion that the
name capensis can be retained for this form, as it is a synonym of another species
of the same genus. It is. moreover, well distinguished from Kraussina rubra.

73. Kraussina pistjm, Valenciennes, apud Lamarck, sp. (Plate XXI. figs. 1-4..)

Terebratula pisum, Valenciennes, apud Lam. Animaux sans Vert. vol. vi. p. 330, 1819.

Ter ebr atula Natalensis, Kuster, Martini & Chemnitz, Conch. -Cab. vol. vii. p. 3G, pi. 2h. fio-s. 4-7
1843.

Terebratula Alt/oensis, G. B. Sowerby, Proc. Zool. Soc. 1846, p. 95 ; and Thes. Conch, p. 302,
pi. Ixxi. figs. 91, 92, 184G.

Terebratula Nataleiisis, Krauss, Sudafrikanischen Mollusken, p. 33, pl. ii. fig. 11, 1848.

Terebratula piston, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 370, 1852.

Kraussia pisum, H. & A. Adams, The Genera of Recent Mollusca, vol. ii. p. 579, pl. cxxxi. figs. 4«, A, 1858.

Kraussina pisum, E. Suess, Ueber die Wohusitze der Brachiopoden, Sitzuugsb. k. Akad. der Wisseiisch.
Wien, Bd. xxxvii. p. 211, 1859.

Terebratula [Kraussia) pisum, Lovell Reeve, Conch. Icon., Monogr. Tereb. pl. is. fig. 36, a, b, 1861.

Kraussina pisum, Uall, Amer. Jom-n. of Couch, vol. vi. p. 140, 1870; Davidson, Report on the
Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. vol. i. p. 54, pl. iv. figs. 7, 8, 1880.

Shell suborbicular or oval, often rather wider than long, light yellowish white. Dorsal
valve very slightly convex, with a groove-like central longitudinal depression extending
from the umbo to the front. Hinge-line nearly straight, and rather more than half as
long as the breadth of the shell. Ventral valve deeper than the dorsal one, longitudinally
keeled, beak slightly incurved, with a rather large incomplete foramen, and two small
lateral deltidial plates ; beak-ridges sharply defined, leaving a flattened area between
them and the hinge-line. Surface of valves covered with numerous small radiating ribs,
which increase in number at variable distances from the beak and umbo, owing to the
bifurcation of many of the ribs and the interpolation of shorter ones. Valves crossed
at variable intervals by fine concentric lines of growth. In the interior of the dorsal
valve the hinge-plate is narrowed, a very slightly raised mesial septum extending from
the middle of the hinge-plate to about half the length of the valve. From the anterior
extremity arise two short, deviating, flattened, and forked lamellge, expanded at their
extremities ; two eye-shaped depressions due to peduncular muscles He on each side of
the posterior extremity of the hinge-plate. The brachial a])pendages are small, and do
not occupy a space larger than about half the length of the valve ; central spiral lobe
very small. Length 8 lines, breadth 8 lines, depth 3 lines.

Hab. This species was dredged by the ' Challenger ' Expedition off" the Cape of Good
Hope, at a depth of 150 fathoms. It has also been obtained near Natal, and by Sir E.
Belcher in the same localities.

Obs. This species is well distinguished from Kraussina Lamarchiana by its numerous
delicate raised strife, but it is scarcely distinguishable from Kraussina Deshayesi, except

second series. — ZOOLOGY, VOL. IV. 17

124 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

by its colour, the last-named species beinsj rather more triangular in form and marked
with deep crimson rays. Krcmssina Lamarckiana is also a much smaller species than
Kraussina pisum. At p. 33 of his ' Siidafrikanischen Mollusken,' Dr. F. Krauss expresses
the opinion that the Terehratula Algoensis of Sowerby is a synonym of the species under
description : this is very probably the case, and not of K. rubra as was supposed by Lovell
B-eeve.

73. Keaussina (Megeklina) Lamakckiana, Davidson. (Plate XXI. figs. 7-11.)

•

Kraussia Lamarckiana, Davidson, Proc. Zool. Soc. 1852, p. 80, pi. xiv. figs. 23, 23; Ann. & Mag.
Nat. Hist. 2nd ser. vol. ix. p. 370, 1852; lutr. to vol. i. of Brit. Foss. Brach. p. 69, 1853; Woodward
& Gray, Cat. of Brachiopoda in the British Museum, p. Ill, 1853; H. & A. Adams, The Genera of
Recent Mollusca, vol. ii. p. 579, 1858; S. P. Woodward, A Manual of Mollusca, p. 218, fig. 120, 1858.

Kraussina Lamarckiana, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungb. k. Akad. der
Wissensch. Wien, Bd. xxxvii. p. 21], 1859.

Terehratula {Kraussia) Lamarckiana, Lovell Reeve, Conch. Icon., Monogr. Ter. pi. ix. fig. 34', 1861 ;
Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 182, 1861.

Kraussina Lamarckiana, Chemnitz, Man. de Conch, vol. ii. p. 206, fig. 1057, 1862; Dall, Amer.
Journ. of Conch, vol. vi. p. 139, 1870; Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 190; Hutton, Cat.
of the Marine Mollusca of New Zealand ; Tenison Woods, Census of the Marine Shells of Tasmania, Proc.
Roy. Soc. of Tasmania, p. 34, 1877; Davidson, Report on the Brachiopoda, Voyage of H.M.S. 'Chal-
lenger,' Zool. vol. i. p. 53, pi. iv. fig. 9, 1880.

Megerlina Lamarckiana, E. Deslongchamps, Etudes critiques sur des Brachiopodes nouveaux ou peu
connus, p. 159, pi. xix. fig. 11, 1884.

Shell small, somewhat subquadri lateral, about as wide as long, flexuous, fulvous
white or light brown. Dorsal valve slightly convex, with a rather deep longi-
tudinal mesial depression. Hinge-line straight, and rounded at its angles. Ventral
valve deeper and more convex than the dorsal one, longitudinally keeled along the
middle. Beak slightly incurved, and truncated by a large incomplete foramen, laterally
margined by two rudimentary deltidial plates ; beak-ridges sharply defined, leaving a
false areal space l)etween them and the hinge-line. Surface of both valves ornamented
by a number of small radiating costse, increasing in number by the interpolation of
shorter ribs. Length 4 lines, breadth 4i lines, depth 2 lines.

In the interior of the dorsal valve the hinge-plate is wide and concave, with two eye-
shaped rudimentary scars between its outer margins. Under the middle of this plate a
slightly raised mesial septum, thickened, and most elevated near its anterior extremity,
extends to less than half the length of the shell ; close to its anterior extremity arise two
deviating, ^ -shaped, broad lamellae, slightly expanded and curved at their extremities ;
under these, on each side of the septum, are attached two slightly projecting, wide,
curved rudimentary lamellae, which simulate the part of the principal lamella? attached,
in other genera, to the sides of the septum. The bottom of the valve is costated and
faintly tuberculated ; a row of short, erect spine-like asperities rising perpendicularly
close to and all round the inner margin. Brachial appendages small, the central lobe
being the least. Shell perforated by small canals.

Sab. Dredged in great abundance by Mr. Brazier in Double Bay, Port Jackson, New

DE. T. DAVIDSON OX RECENT BEACHIOPODA. 125

South Wales ; and l)y the ' Challenger ' Expedition near Sydney, attached to specimens of
JT'aldheimia Jlavescens, fonnd close to the shore. The Rev. Teuison Woods states
that the shell occurs in ahundance under stones at low water at Tamai Heads, also
oflP the south-east coast of Australia and New Zealand, and occasionally at Long Bay.
I have never seen any New-Zealand examples.

Obs. — This small species is distinguishahle from Kraussina 2>isum by its much
smaller dimensions and comparatively stronger ril)s, as well as by some interior details.
It has been fortunate in retaining its specific name unchanged since first described. I
have through the liberality of Mr. Brazier been able to examine an extensive series of
specimens from half a line up to four lines in length. When very young the shell is
quite circular, with very few ribs, and these commence only at al)out half its length,
and extend to the lateral and frontal margins. On account of the shortness of its
peduncles the beak and umbo are often eroded and worn. In very young specimens
the septum and deviating lamellae are rudimentary and undeveloped. We are indcl)ted to
M. E. Deslougchamps for the discovery of the short accessory rudimentary lamellae that are
attached to the anterior lateral sides of the septum under the Y-shaped deviating lamellae.

M. E. Deslongcliamps describes the interior characters of this and its allied forms
with considerable care and minuteness at p. 122 of his 'Etudes critiques.' He remarks,
that having been able to observe the calcareous appendages in adult examples only of
lLraussi)/a rubra, he can affirm nothing positive as to the manner in which they have
been produced, but that the disposition of these appendages — first in Kraussina
Davidsoni, and, secondly, in K. Lamarchiana — establishes points of transition so complete
between the genera Megerlta and Kraussina that he feels no uncertainty respecting
the position of these two genera in the zoological series, and that they certainly belong to a
single group. He states that the differences between the adult conditions of Kraussina
rubra and 3IegerUa truncata, although seeming at first sight very striking, disappear
or become much less conspicuous Avhen an adult Kraussina Lamarckiana is compared
\^'ith the transition-stages of Megerlia truncata, traces being found in K. Lamarckiana
of all the parts that constitute the calcareous processes in Megerlia [truncata).
M. Deslongchamps would therefore propose a subgenus Megerlina for the reception of
K Lamarckiana and K. Davidsoni, which, according to his views, constitute the passage-
forms between Kraussina rubra and Megerlia truncata.

In his figure of K. Lamarckiana, M. Deslongchamps draws the hinge-plate simple
and concave ; but in my specimens it is quite similar to that of Kraussina rubra, with the
two eye-shaped scars due to the peduncular muscles ; and the only essential difference
that I can see is the presence of the short, broad, curved lamellaj that are attached to
the mesial septum under the upper forked deviating appendages.

The diflerences and resemblances between the diff'ereut forms here alluded to will be
better understood by a glance at the figures in Pis. XX. and XXI. The brachial
aj^pendages in very young specimens of K. Lamarckiana are extremely small, as well as
the calcareous appendages for their support.

M. Deslongchamps informs us, moreover [loc. cit.), that in Kraussina the spicula are

17*

126 DE. T. DAVIDSON ON EECEXT BRACHIOPODA,

very thiu, detached, and elongated, but in Megerlina they are more or less thick, and
approach more to those of Megerlla.

So far back as 1852 (Proc. Zool. Soc.) I stated in my paper, " Descriptions of a few
New Species of Recent Brachiopoda," that K. Lamarckiana "is distinct from K. pisum
and K. Deshayesii by its somewhat tetragonal shape, stronger and fewer costae, as well
as by the details of its loop, relating it more than any of the other species of Kraussia to
the section Megerlia," and 1 am glad to find that in 1884 M. Deslongchamps has con-
firmed the opinion I expressed in 1852.

74. Kraussina (Megerlina) Davidsoni, Velain. (Plate XXI. figs. 12-14.)

Kraussina Davidsoni, Velain, Archiv de Zoologie Experiraentale, 1877, p. 139, pi. v. figs. 23, 24 ; and
Malacologie de I'lle de St. Pavil ; Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challenger,'
Zool. vol. i. p. 21, 1880.

Megerlina Davidsoni, E. Deslongchamps, Etudes critiques sur des Brachiopodes nouveaux ou peu
connus, p. 159, pi. xix. figs. 9, 10, 1884.

Shell small, rather thick, globose, variable in form, pouch-shaped, longer than wide,
or slightly transverse and suborbicular. Dorsal valve convex, with a mesial depression
or groove of greater or lesser depth. Ventral valve rather deeper than the dorsal one,
longitudinally keeled ; beak short, slightly incurved, and truncated by a large incomplete
foramen, margined anteriorly by the umbo of the dorsal valve, and laterally by two
small deltidial plates. Surface either partially smooth or radiately ribbed, ribs increasing
in number by the interpolation of shorter riblets. Surface crossed by strongly marked con-
centric lines of growth. Colour darkish brown, verging on black. Length 4 lines, breadth
3 or 3| lines. In the intei'ior of the dorsal valve the hinge-plate is comparatively large and
concave, with two eye-shaped peduncular scars between its lateral portions. Septum of
very small elevation, extending from the middle of the base of the hinge-plate to about
half the length of the valve ; from its anterior extremity arise two deviating Y-shaped
lamellee, slightly curved at their extremities ; under these and also attached to the
septum are two small rudimentary plates. The bottom of the valves is covered with large
projecting tubercles, which are most prominent close to the margin of the shell.

Mab. This species was collected by M. C. Velain in large numbers at the Island of St.
Paul, in 1874, during the Prench expedition to observe the transit of Venus. M. Velain
states that these Brachiopoda live in abundance in the interior crater of the island, on its
littoral side open to the sea ; that during the ordinary low tides they are scarcely covered
by water, and are alternately covered and left bare by the ebb and flow of the tide. They
occur in an area of a few yards width, and, consequently, at shallow depths, doubtless
because they find those conditions to which they are accustomed in other localities. M.
Velain informs me that during his lengthened stay at the Island of St. Paul no other
species of Brachiopod was found ; that the shell referred to by Mr. Dall as Kraussina
picta, Val., Verb, zool.-bot. Ges. Wien, p. 894, 1865, as from the Island of St. Paul, has
been nowhere described, and that the name must be attributed to an incorrect citation.
This has subsequently been admitted by Mr. Dall.

DE. T. DAVIDSON ON KECENT BRACHIOPODA. 127

Obs. This small species is nearly related to Krcntssina Lamarckiana, but it is more pouch-
shaped, and differs from it in several exterior and interior details. From the shortness
of its peduncle, the beak and umbo are generally much worn from friction. Some
specimens are ribbed only on the posterior half of the valves, while on others the surface
is regularly ribbed throughout. The interior details have been described under Kraussina
{MegerUna) Lamarckiana, and need not therefore be repeated.

75. Kraussina Atkinsoni, Tenison Woods, sp. (Plate XXI. figs. 5, G.)

Kraussia Atkinsoni, Tenison Woods, Census, with brief deseriptions, of tlie Marine Shells of Tasmania,
Proc. Koy. Soc. Tasmania, 1878, p. 57.

Shell small, somewhat subpeutagonal, widest about the middle, indented iu front.
Marginal line Hexuous. Dorsal valve gently convex, divided longitudinally into two
lobes by a deep, wide, angular sinus ; lateral sides of the umbo auriculate. Ventral
valve deeper than the dorsal one, with a longitudinal mesial elevation or fold ; beak very
slightly incurved, pointed, with a rather large incomplete foramen, margined anteriorly
by a portion of the umbo of the opposite A^alve and by narrow elongated lateral deltidial
plates ; margin-line in front angular. Surface of valves smooth, marked by tine concen-
tric lines of growth. Colour light greyish yellow. Length 3 lines by 2^ in breadth and
Ij in depth. In the interior of the dorsal valve the hinge-plate is excavated along tlie
middle ; septum very slightly elevated, extending from the middle of the base of the hinge-
plate to about half the length of the valve. From the anterior extremity of the septara
rise two deviating folded lamellse.

Hub. Dredged at Long Bay, South Tasmania, by the Eev. IL. D. Atkinson, iu 10
fathoms water.

Obs. I am indebted to the Eev. Tenison Woods for my knowledge of tliis well-marked
small species. It can hardly be said to have been described, for all that Woods says is
that " This is a shell about the size of the last {K. Lamarckiana), but more depressed, with
a smooth valve." Kraussijui Atkinsoni is at once distinguished from its congeners by
being the only smooth species of the genus with which we are acquainted, and also by
the shape of its shell.

Subfamily ARGioPiNiE.

In this subfamily we would include the genus Argiope, Deslongchamps, lSi2
(=Megathi/ris, d'Orbigny, 1847), and the subgenus Cistella, (iray, 1853, both being
closely related to the Terebratulidse, of whicli they form a part, and distinct from the
Thecidiidae, which the larger number of zoologists and palaeontologists would form
into a separate family.

W^e are well aware that the name Argiope was j^roposed in 1827 by Savigny and
Audouin (Descr. de I'Egypte, ed. 2, xxii. p. 334, pi. ii. fig. 6) for a genus of Egyptian
Spiders ; but as tlie name Argiope has been very generally adopted for a genus of Bra-
chiopods, I am disposed to retain it for that purpose.

In Argiope proper there are three or five prominent submarginal septa, the lamella

128

DE. T. DAVIDSON ON EEUENT BRACHIOPODA.

forming the loop being four-lobed, adhering to the septa, and more or less confluent with
the valve.

In CisteUa there is but one prominent submarginal septum, the loop, or semicircular
lamella, being two-lobed. In the first the labial appendages are folded into four lobes,
in the second into two.

The animal and its embryology have been carefully studied, described, and illustrated
by such excellent observers as W. Dall, Kowalevsky, A. E. Shipley, M. A. Schulgin, and
S. P. Woodward, as well as by myself and others, and these investigations will be fully
alluded to in the description of the species.

We know with certainty of but one species of At^giope in the recent condition, the
Argiope decollata of Chemnitz. To this section Schulgin would add the A. Barroisi
Shnd A. globuliformis; hut as I have never seen those two species or their interiors, I
cannot feel certain whether they should be classed with Argiope or with Clstella.

We are acquainted with the following eight or nine recent species of the genus CisteUa,
viz. : —

1. CisteUa neapolitana, Scacchi, 1833.

2. ■ Koivalevskii, Schulgin, 1884.

3. cisteliula, S. Wood, 1840.

4. IVoodwardiana, Davidson, 1866.

5. cuneata, Risso, 1826.

6. CisteUa Barrettiana, Davidson, 1866.

7. Schrammi, Crosse, 1866.

8.
9.

liitea, Dall, 1870.
lunifera, Philippi, 1836.

76. Argiope decollata, Chemnitz, sp. (Plate XXI. figs. 30-35.)

Anomia decollata, Chemnitz, Conch.-Cab. vol. viii. p. 96, pi. Ixxviii. fig. 70.5, 1785.
Anomia detruncata, Gmelin, Syst. Nat. p. 3347, 1788.
Terebratula ungula, Retzius, Nov. Gen. Test. 1788.

Terebratula detruncata, Bruguiere, Encycl. Meth. tab. 243, fig. 10, 1789.
Anomia detruncata, Dillwyu, A Descrip. Cat. of Shells, p. 292, 1817.
Terebratula detruncata, Blainville, Diet. Sc. Nat. vol. liii. p. 141, 1828.
Terebratula aperta, Blainville, Diet. Sc. Nat. vol. liii. p. 144, 1828.

Terebratula decollata, Deshayes, Encycl. tab. ccxliii. fig. 10, 1830; Cantraine, Bull. Acad. R. des
Sciences de Bruxelles, 1835.

Terebratula dimidiata, Scacchi, Osserv. Zool. p. 17, 1833, and Cat. Conch. Regni Neapolitani, p. 8, 1836.
Terebratula detruncata, Scacchi, Cat. Conch. Regni Neapolitani, p. 8, 1836.

Terebratula urna antiqua and T. cardita, Risso, Fauna Europ. Mer. vol. iv. pp. 387, 389, pi. xii.
figs. 177, 180, 1826.

Terebratula decollata, Lamarck, An. sans Vert. ed. 2, vol. vii. p. 350, 1836.

Terebratula detruncata, Philippi, En. Moll. Sicilije, vol. i. p. 96, tab. vi, fig. 14, 1836.
Arr/iope decollata, E. Dcslongchamps, Mem. Soc. Linn, de Normandie, vol. vii. p. 9, 1842.

Orthis detruncata, Philippi, En. Moll. Siciiise, vol. ii. p. 69, 1844.

Terebratula detruncata, Forbes, Rep. on the Moll, of the ^gean Sea, p. 141, 1844; D. Galvani, 111,
delle Couch, fossili, 1845.

Terebratula decollata, G. B. Sowerby, Thes. Conch, i. p. 355, pi. Ixxi. figs. 68-70, 1846.

Megathyris detruncata, A. d'Orbigny, Comptes Rendus Acad, des Sciences, 1847; Annales des
Sciences Nat. Zool. 3'' ser. vol. viii. p. 341, 1847; Paleontologie Fraufaise, Ter. Cret. vol. iv. p. 146.

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 129

Ortltis detruncaia, G. Michelotti, Descr. des Foss. Jliocenes, p. 78, 181"; A. Aradas, Descr. delle
Conch. Foss. di Gravitelli, p. 14, 18-17.

Terebratula pectiniformis, Costa, Mem. Reale Accad. delle Scienze di Nap. vol. v. p. 39, pi. i. fig. G.

Orthis di'lrancata, Costa, Fauua del Regno di Napoli, pi. ii. figs. 6-7, 18."j1.

Aryiope dccollata, Davidson, Ann. & Mag. Nat. Hist. vol. ix. p. 373, 1852; "Woodward & (Jniy, Cat.
of the Brachiopoda in the Brit. Mus. p. 113, 1853; Davidson, Brit. Foss. Bracli. vol. i. Introduction,
p. 73, figs. 22-23, and pi. vi. figs. 32-33, 1853 ; S. P. Woodward, A Manual of the Mollusca, p. 220, 1856.

Jrt/iojje detrmicata and A. dccollata, Pictet, Traite do Pal. vol. iv. p. 27, 1857.

Aryiope decollala, A. Adams, The Genera of Recent Mollusca, vol. ii. pi. exxxi. fig. 6, 1858; Deslong-
champs. Bull. Soc. Linn, de Normandie, vol. iii. p. 122, 1858.

Orihis decoUata, Requiem, Coq. de la Corse, p. 35.

Artjiope decoUata, Gwyu Jeffreys, Ann. & Mag. Nat. Hist. 3rd ser. vol. ii. p. 124, 1858; E. Suess,
Ueber die Wohnsitzc der Brach. Acad, der Wissenscli. Wien, Bd. xxxvii. p. 213, 1859.

Terebratula {Arglope) decollata, Lovell Reeve, Conch. Icon., Monogr. of Ter. pi. x. fig. 43, 18G1 ; and
Ann. & Mag. Nat. Hist. 3rd ser. vol. vii. p. 185, 1801.

Argiope decollata, Chemnitz, Man. de Conch, ii. p. 209, figs. 1067-1069, 1862; E. Deslongchamps,
Recherchcs sur I'Organisation du Manteau chez les Brachiopodes, p. 291, pi. iii. figs. 8, 9, 1864-
Gwyn Jefi"reys, Brit. Conch, vol. ii. p. 18, 1863, and vol. v. p. 164, pi. xix. fig. 3, 1869; Davidson,
Brachiopoda of the jMaltese Islands, Ann. & Mag. Nat. Hist. 3rd ser. vol. xiv. p. 9, pi. i. figs. 11, 12,
1864; Seguenza, Mem. Soe. Ital. di Scienze Nat. vol. i. p. 69, 1865 ; S. Brusina, Moll. Dalmati, p. 47,
1866 ; C. WeinkaufF, Die Conch, des Mittelmeeres, p. 288, 1867 ; Davidson, Ital. Tert. Brach., Gcol.
Mag. vol. vii. pi. xxi. figs. 5-8, 1870.

Megathyris decollata, Dall, Amer. Journ. of Conch, vol. vi. p. 145, 1870, and Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 193.

xirgiope decollata, P. Fischer, Brachiopodes des Cotes Oceaniques de France, Journ. de Conch, vol. viii.
p. 377, 1870, and Conchyl. dc la Gironde, Soc. Linn, de Bordeaux, p. 172, 1874; Gwyn Jeffreys, Proc.
Zool. Soc. 1878, p. 409; Zittel, Handbueh der Palaontologie, p. 697, 1880; Davidson, Report on
the Brachiopoda, Voyage of H.M.S. ' Challenger,' Zool. i. p. 57, pi. iv. figs. 12, 13, 1880.

Megathyrh decollata, J. de IMorgan, Bull. Soc. G(iol. de France, vol. viii. 1883.

Argiope decollata, Schulgin, Zeitschrift fiir wissensch. Zool. Band xli. pi. viii. figs. 1-11, 1884.

Shell small, variable in shape, generally semioval or obscurely subpentagonal, rounded,
laterally and in front, obtusely angular posteriorly. Hinge-line nearly straight, as long
as the greatest breadth of the shell, with generally acute cardinal extremities. Dorsal
valve semicircular, gently convex. Ventral valve rather deeper than the opposite one ;
beak prominent, nearly straight ; foramen large, incomplete, margined anteriorly by a
considerable portion of the umbo, laterally by very small rudimentary deltidial plates ;
beak-ridges sharply defined, leaving between them and the hiuge-line a wide triangular,
flattened area. Surface of valves ornamented with from ten to fourteen rounded cori-e-
sponding ribs, the two central ones generally deviating so as to admit one or two shorter
ribs between them. Surface of both valves crossed by equidistant, slightly projecting
lines. Teeth short, sockets broad and deep. In the interior of the dorsal vahe the
hinge-plate is long, narrow, and concave, without any defined or prominent cardinal
process. Three or five submarginal septa, most elevated anteriorly ; the three central
ones the largest and most prominent. The loop, composed of a ril^and-shaped lamella,
is first attached to the hinge-plate, then cvu'ved to fit into the hollows between the

130 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

septa, which adhere to the sides of the hinge-plate, and are more or less confluent with the
valve. Labial processes folded into four lobes, united by a membrane, forming a
brachial disk with long cirri. Mantle extending to the margin of the valves, and
closely adherent. A tu.berculated flattened margin surrounds the valves. In the
interior of the ventral valve a triangular plate occupies the posterior portion of the inside
of the fissure, and from under the centre of which extends a short mesial septum. Shell-
structure punctate. Colour dull yellow or white. Length 3 lines, width 4 lines, depth
2 lines.

Hab. Mediterranean Sea ; J]]gean Sea, at a depth of from 27 to 100 fathoms (Forbes) ;
Straits of Samos ; Atlantic coast of Spain and of France, off Cape Breton, in upwards
of 45 fathoms, two miles east of Guernsey, 18 fathoms ; off Madeira in 20 fathoms
(M° Andrew) ; Canary Islands ; Rhodes (Fischer) ; Guetaria in 80 fathoms (Hidalgo). Costa
informs us that Argiope decollata occurs plentifully near the islands of Capri, Ischia,
Palmieri, and in the Gulf of Taranto. The 'Challenger' Expedition obtained it in great
abundance at Gomera, off Teneriffe, in 73 or 75 fathoms.

It is a common fossil in the Upjier Tertiaries of Italy, Sicily, Malta, and is found at
Nice and elsewhere ; also in rocks of Miocene age.

Ohs. Dr. S. P. Woodward and myself were able to give the first description and illus-
trations of the manner in which the loop and brachial appendages are arranged in this
important genus and species (Ann. & Mag. Nat. Hist. vol. ix. May 1852). Since then
Dr. Gray proposed to separate from the genus Argiope all those forms with a single
submarginal septum, uniting them into the subgenus Cistella. Up to the present time
we are acquainted with only a single recent species of Argiope, but there are several
fossil species referable to the genus.

In his admirable memoir ' Eecherches sur I'Organisation du Manteau chez les Brachio-
podes articules,' p. 29, 1864, M. E. Deslongchamps asserts that, properly speaking,
no pallial apparatus (of spicula) exists in the genus Argiope. The whole of the mantle,
which is stretched like the skin of a drum between the arched branches of the dorsal
valve, is pervaded merely by an amorj)hous calcareous substance, the presence of which
is indicated by a slight effervescence when the mantle is submitted to the action of dilute
acid. The labial appendages and their cirri are equally devoid of definite calcareous
structures, although their yellowish aspect in dried specimens might lead at first sight
to a contrary supposition. If, however, the raised up j)ortion of tlie mantle in the larger
valve be examined at tlie place wliere it forms the walls of the visceral cavity, a con-
centric line of detached spicula may be seen when sufficiently magnified, elongated
perpendicularly to the direction of the front, and nearly similar in aspect to those of
Kraussina. Some small calcareous particles of an angular and irregular shape may also
be seen. The genus Argiope thus shows a manifest passage from a mantle entirely
destitute of calcareous bodies to one where spicula are more or less numerous, as
in Terebratulina, Terehratula, Kraussina, Megerlia, and Ilorrisia.

In his "Note sur quelques especes nouveUes de Megathi/rides," Bull. Soc. Zool. de France,
vol. viii. 1883, M. J. de Morgan strongly advocates the adoption of A. d'Orbigny's generic

DR. T. DAVIDSON ON EECENT EEACIIIOPODA. 131

name Ilegathyris, 1817, in preference to that of Argiopc, proposed in 1817 by E. Deslong-
champs. He also describes, with considerable detail, the aniiual and its shell. He gives the
follow ing diagnosis of the animal: — ^" Oval, fixed, provided with a mantle disunited at the
edges, thickened and ciliated, cut out into four lobes like clover ; gills formed of a ramified
vascular net-work. Body small, uii[)r()vided with arms ; peduncle short, tendinous, issuing
from a cardinal foramen in tlie upper or ventral valve." The peduncle is, indeed, so
short that the beak is often much yfovw from friction, due to its close contact with
the objects to which the shell is attached.

Tlie species of Cistella are more numerous, both in the recent and fossil conditions,
than are those of Argiope.

In 1790, AVulfen published some good figures of ^. decollata, as well as of T. seminula.

77. Cistella Is"eapolitana, Scacchi, sp. (Plate XXII. figs. 8-21.)

Terebratula neapoUtana, Scacclii, Osserv. Zoologiclic, ii. p. 18^ 1833, aud Cat. Conch. Rcgni Xcap. p. 8,
1836; Kustcr, New ed. Chemnitz, Concli.-Cab. p. 32, 1813.

Orthis necqjoUtana, Philippi, En. IMoll. Sic. ii. p. 69, 1811; Costa, Fauna del Regno di Napoli, p. 37,
pi. iii. figs. 1, 3, 5, 1851.

Argiope neapoUtana, Davidson, Proc. Zool. Soc. 185.2, p. 81, pi. xiv. figs. 21, 25, and Ann. & ilag.
Nat. Hist. 3rd scr. vol. viii. p. 40, 1861.

Argiope Forbesii, Davidson, Ann. & Mag. Nat. Hist. 2nd scr. vol. ix. p. 373, 1852.

Argiope neapoUtana, S. P. Woodward, A ^Manual of the ^MoUusca, p. 220, fig. 125, 1856; E. Sncss,
Uebcr die Wolmsitze der Brachiopodcn, Sitzungsb. k. Alcad. Wissenscli. Wien, p. 213, 1859; Davidson,
Brit. Foss. Brachiopoda, Introduction to vol. i. p. 73, fig. 21, 1853.

Terebratula [Argiope) neapohtana, Lovcll Rccvc, Conch. Icon. Mouogr. Ter. pi. x. fig. 15, 1861, and
Ann. & Mag. Nat. Hist. 3rd scr. vol. vii. p. 180, 1861.

Argiope neapoUtana, Chemnitz, Man. de Conch, ii. p. 209, figs. 107-1, 1075, 1862; H. C. Wcinkauft",
Conch, dcs Mittelmeeres, p. 290, 1867.

Cistella neapoUtana, Dall, Amor. .Journ. of Conch, vol. vi. p. 146, 1870, and Philadelphia Acad. Nat.
Sciences, 1873, p. 194.

Argiope neajiuUtana, Kowalcvsky (in Rnss. INIoscow, 1874), Observations sur le Developpcmcnt dcs Bra-
chiopodes. Analyse par !MM. Oehlert and Dcniker, in Archives de Zool. Experim. 2" scr. tom. 1. pp. 57-76,
1883; Gwyn Jeffreys, Proc. Zool. Soc. 1878, p. 409; S. Brusiua, MoUuschi Dalmati, p. 47, 1866.

Argiope biplicata, Scgueuza, Rendiconto Accad. dclle Scienze Fisiche ct Matcmat. Napoli, xv.
pp. 123, 124, 1876.

Argiope neapoUtana, A. E. Shipley, On the Structure and Devclopmcut of Argiope, Mitthcil. a. d.
Zool. Station zu Ncapcl, Bd. iv. p. 494, 1883.

Shell small, somewhat triangularly orbicular, broadest anteriorly, obtusely angular
posteriorly, plicalely indented at the margin and especially in front. Dorsal valve very
moderately convex and flattened, with a mesial longitudinal depression commencing at a
short distance from the umbo and extending to the front ; hinge-line obtusely angular,
nearly straight, and rather more than half the lengtb of the breadth of the shell ; lateral
sides of the umbo auricular. Ventral valve very moderately or tumidly convex, with a
longitudinal mesial depression (as in the dorsal valve) commencing near the extremity of
the beak and extending to the front. Beak short, slightly incurved and truncated by an

SECOND SERIES. — ZOOLOGY, VOL. IV. 18

132

DR. T. DAVIDSOX OX EECENT BEACHIOPODA.

Fiff. 10.

incomplete foramen, marp^ined anteriorly by the umbo of tlie opposite valve, and laterally
by two small deltidial plates ; beak-ridges sharply defined, leaving between them and
the hinge-line a small triangular flattened space. Surface of valves smooth, or Avitli from
two to six rounded ribs, more or less defined in different specimens. Sliell semitrans-
parent, white or yellowish brown. Shell-structure punctate.
Length 2^ lines, breadth 2 lines, depth 1 line. In the inte-
rior of the dorsal valve the hinge-plate is long and narrow,
without any defined cardinal process. Under its centre a
triangular-shaped j)late or septum gradually rises, and extends
to four fifths of the length of the valve, being most
elevated near to its anterior extremity. Loop two-lobed,
attached to the base of the hinge-plate and again to the
anterior extremity of the submarginal sejjtum, and more or
less confluent with the valve. Labial processes folded into
two lol)es, united by a membrane forming a brachial disk
fringed with long cilia. Mantle extending to the margin,
closely adherent. In the interior of the ventral valve a small
septum extends from under the beak to about half the
length of the shell ; margins of the valves much thickened
within.

Bah. Mediterranean, at depths of from CO to 100 fathoms ;
Bay of Naples, off the islauds of Capri and Ponza ; J^gean
Sea.

Obs. Some malacologists have expressed the opinion that

Terehratula semhiula, Philippi, is a synonym of C. neapoli-

tana ; but the foraminal umbo of the dorsal valve in the
first-named shell would render that view doubtful.

Exteriorly Cistella neapoUtana is a well-marked species,

although it varies a good deal in shape, being also either

quite smooth or obscurely ribbed.

Kowalevsky has described and illustrated in great detail

the development of C. neapoUtana. MM. Oehlert and Deniker

have published an excellent summary of this memoir, most

useful to those who are unable to read the Russian language.

Kowalevsky states that the eggs, after they are detached

from the ovary, fall into the general cavity of the body,

enter the oviducts by the funnel-shaped opening of these

organs, and pass into the incubatory pouches, situated on the

ventral lobe of the female individual, where they are deve-
loped. He is of opinion that fecundation must, without

doubt, be accomplished either during the passage of the egg

along the oviduct or in the general cavity.

Argiope neapoUtana (after
Kowalevsky).

A. Egg after the invagination of
a part of the blastoderm :
d, cavity formed by the in-
vagination ; a, orifice of the
cavity ; o, exterior layer (up-
per) ; V, interior layer.

E. The embryo divided into two
segments.

C. Embryo, in which the folding
of the mantle already covers
a part of the caudal seg-
ment : rt, cephalic segment;
6, thoracic segment ; c, cau-
dal segment ; s, bundles of
bristles.

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

133

First Period. — From the Commencement of the Development of the Egg up to the

moment toheii the Larva fixes itself

In the least advanced state, as observed by Kowalcvsky, the egg presents the aspect
of a vesicle, the sides of which are composed of little cylindrical cells surrounding a
small cavity. Soon after a portion of a blastoderm becomes invaginated (woodcut,
fig. 10, A) the extremities of the gastrula approach each other, and leave between them
only the place of an opening. At tliis moment the embryo presents two layers of small
cells ; one of them is the outer layer of tlie blastodenn, the other the inner layer; and
it is at the expense of this last that tlie middle segment, as well as all subsequent modi-
fications, are formed.

In the next stage the cavity divides itself into three lobes (one median and two lateral),
which communicate at the part nearest to the orifice.
This orifice is conuectcd with the median lobe by
means of a narrow canal, the walls of which present
two small prominences formed of small cells distinctly
differentiated. Soon after the embiyo divides itself
transversely into two segments, the one upper and
large (cephalic segment), the other narrower and more
conical (caudal segment). (Woodcut, fig. 10, B.)

At this period tlie three lobes of tlie internal
cavity become separated from one another, and form
three isolated cavities. The median cavity presents
at its posterior portion so great an approximation to
its walls that these last appear as partitions. At the
lower part the median cavity is surrounded, in addi-
tion to its own walls, wliich are formed of cylindrical
cells like the envelopes of the other cavity, l)y a
second layer of small pale-coloured hexagonal cells,
which for some distance are in direct relation with
the external layei'. (Kowalevsky is unable to explain
either the origin or the signification of this laver.)

Afterwards the median cavity is transformed into
a digestive tulie : perhaps these walls form the intes-
tino-glandular layer. The lateral cavities constitute
the general cavity of the body ; the interior part of
their walls jn-oduces the mesentery and perhaps some
muscular fibres (intestino-muscular layer of the
middle layer) ; the outer part mainly contributes to
the principal muscles.

Kext follows a stage wherein the embryo is divided
into three segments (woodcut, fig. 10, C), the last

Adult larva of Argiope neapolitana
(alter Kowalevsky).

Swimming freely, y, eyes ; r, edge of the
cephalic segment ; », cylindrical part re-
uniting the cephalic segment to the tho-
racic segment ; m, mantle ; i, rudiment
of the iute.-tiue ; e, mesentery (a part of
the mantle covering over the caudal
segment) ; a, muscles going from the
dorsal pait to the ventral part of the
valve ; h, abdominal muscles ; c, muscles
of the cephalic segment ; s, bristles.

18*

134 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

segment to appear being tlie median or tlioracic segment, wliicli lias probably been
formed by a division of the caudal segment.

The thoracic segment carries four bundles of bristles, of which two are median and
two lateral ; each bundle is composed of four or five immovable cylindrical and blunt
bristles (woodcut, fig. 10, C).

At the succeeding stage the mantle commences to appear under the form of two
folds covered with cilia, which rise from the ventral and dorsal sides of the thoracic
segment.

This folding of the skin (future mantle) soon becomes developed and partly covers the
caudal segment. The bristles, which are then situated on this fold, become larger and
pass beyond the caudal segment. At the same time two pigmentary spots appear on the
dorsal side of the cephalic segment.

The author was not able to observe the intermediate j^hases between this stage
and that where the larva issues from the incubatory pouch and swims freely. At that
period of the larval development the mantle covers all the caudal segment, whilst
the cephalic segment, which is covered with vibratile cilia, assumes an umbrella-shape,
at the summit of which may be distinguished a portion more or less separated from the
rest (head), which carries four eyes (woodcut, fig. 11, y) : this head corresponds to that
which M. Lacaze-Duthiers has described in Thecidium.

The digestive tube is almost entirely confined to the thoracic segment ; its anterior
portion, however, pentrates a little into the cephalic segment. This last is connected
slightly with the adjoining segment by means of an organ of cylindrical shape.
Kowalevsky could not detect any traces of the nervous system.

The muscular system of the larva is represented by delicate fibres, which pass from
the posterior portion of the intestine to the lateral walls of the thoracic segment.

The mantle is composed of two layers — one external, formed of pavement-epithelium,
the other internal, and consisting of small cylindrical cells. Between these two layers there
are very delicate muscular fibres. The edges of the mantle always carry, on the ventral
side, four bundles of bristles, which, already existing in the preceding stages, have grown
and increased in length.

At this stage the larva swims freely by the help of its vibratile cilia and by slight
movements of the head. At the approach of danger it vigorously contracts itself, and
erects its bristles in all directions. The larva, after swimming for some time, fixes
itself, and then the second stage of its development commences.

Second Period.

The attachment of the larva is effected by means of a sticky substance exuded
by the caudal segment ; as soon as fixed, the larva begins to turn up its mantle
and to raise it above its head, so that in a little time the mantle envelopes the whole of
the cephalic segment. On account of this foldiug-over of the mantle, the external part
of each lobe becomes internal, and the bristles which were on the exterior surface,
being thus carried inside, become unnecessary, and drop off in a few days' time. It

DR. T. DAVIDSON OX EECEXT BEACHIOPODA.

135

is thus seen that it is not these hristles which produce those that horder the mantle
of the adult animal. Argiope, it is true, is not provided with marginal bristles or
setae, but in species wherein they occur they are the result of a new formation of a

Pis. 1-'.

£z^n.

Argiope {CisicUa) nerqjolitanu (after Kowalevskv).

Immediately after it lias become fixed. (The tlioraeio segment lias four bundles of bristles, of which two are
median, and two lateral.) s, bristles ; ij, ej-es ; m, muscles going to the basis of the bristles ; md, adductor
muscles ; 7np, ventral peduncular muscles.

much later period. The lobes of the mantle gradually become invested with a thick
and ridged cuticle, which permits theni to move only in a vertical direction. At tiie
same time the caudal segment is transformed into a peduncle, and the muscles that
proceeded from this last segment to the thoracic segment become ventral peduncular
muscles, the middle pair of muscles changing into divaricators. The head assumes
a spherical shape, and the eyes remain.

At the next stage the thoracic segment grows smaller in size, the digestive canal
becomes round, and a funnel-shaped pit which descends towards the canal is produced
on the cephalic segment. This depression is, in all likelihood, the oesophagus
(gullet). It should be observed that the characteristic feature of this period consists
in the appearance of the brancliias ; these come into existence in the shape of four
nipples directed inwardly and situated on the thickening, of the dorsal lobe near its
border.

The dorsal thickening soon assumes the form of an almost circular swollen ring, and

136

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Fiff. 13.

tlie number of the brancliise amounts to ton (woodcut, fig. 13, b). In the interior of

the swollen ring there exists a cutaneous layer which seems to support all the hrauchia

apparatus, and is pierced by a hole opposite each

of the branchiiie. The branchiae, which are only

prolongations of the swollen ring, are covered with

Tibratile cilia, are provided with flexiljle muscles,

and become erected through their owu elasticity.

The extremities of the branchiae converge towards

the opening of the mouth.

In the following stage twelve tentacles are present,
and at the same time the shell is formed ; but no
tubular perforations are yet seen. Of the following
stases Kowalevsky has been able to trace but oue,
that of the gradual foruiatiou of the shell.

In 187G Signor Seguenza described a small Cistella
under the name Aryiope bipUcata. Dr. Gwyn Jeffreys
considered it to be an abnormal form of C. cuneata, but
I would be more inclined to refer it to A. ncapoUtana ;
only one example was collected.

In his valuable paper on the structure and de-
velopment of Argiope or Cistella neapolllana and C.
cuneata, Mr. A. E. Shipley* observes that " The body
of Argiope lies almost entirely in the dorsal shell,
whose internal skeleton consists of three triangular
plates : one median, the other two lateral and paired."
I find myself, in the specimens of those species, that there is present in the dorsal
valve one prominent submarginal septum only, the loop being two-lobed, adhering to
the septum, and more or less confluent \\\i\\ the valve. The shell is sometimes, when
fresh, sli"litly subtransparent, showing the outline of the lophophore and the red colour
of the egf^s and larvaj. Mr. Shipley describes with much care and detail the minute
structure of the shell; he says (p. 496 et seq.) that it " consists of a number of very-
fine calcareous spicules supported by an organic network On the outer side of

the shell is a layer, in thickness about one eighth of the whole shell, where the
proportion of calcareous matter to organic is enormously increased. The spicules

are here nearly square, and packed against one another like bricks Outside

this is a third layer or periostracum. This is a thick structureless cuticle ; it completely

covers the whole shell, and in the fresh state adheres very closely to it The shell

is pierced by very numerous canals which run completely through the calcareous part,
but their outer end is covered by the cuticle. They are of uniform diameter in the first
part of their course through the first layer, but when they reach the second layer of King,

thev expand and end in funnel shaped mouths They are, as a rule, single but

in the posterior part of the perforate shell, Avhere it is unusually thick, I have seen

* Mitthcilungeu a. d. Zool. Station zu Neapol, Bd. iv. p. 494. 1SS3.

Larva of Ari/iope nenpolitana (after
Xowalevsky).

Condition previous to the formation of the
shell. 6, branchial' ; /, muscular bundle
of the branchiie of the inner side ; Z, head
of oesophagus ; z, divaricator muscles ; i,
stomach ; in.p^ ventral muscles of the
peduncle ; mi, muscles going from the
ventral valve to the upper part of the
dorsal valve ; el, internal envelope ; p,
peduncle.

DK. T. DAYIDSOX OX EECENT BRACHIOPODA. 137

branched canals The minute structure of the internal skcletou is like that of the

inner layer of the shell, there are no canals present The mantle which lines the

internal surface of each shell is formed hy two evaginations of the body-wall On

the outer surface the mantle is in direct communication with the organic basis of the
shell. No setse occur in the mantle of Argiope. Into each of the canals which pierce
the shell, the mantle sends a diverticulum. This is a hollow tube which fits exactly into
the calcareous canal, but, unlike that, is closed at its outer end." ]\Ir. Shipley then
describes at some length the papilte and their supposed functions; but space will not
aUow us to transcribe his account of them, my object being merely to give a few extracts
from his valual)le paper, which should l)e read in its entirety.

"The lophophore [p. 499] lies entirely in the dorsal shell, it forms a great part of the
body wall of the animal. The shape is an oval, the border running parallel with the margin
of the shell, except at the anterior median portion Mliere there is a narrow deep indentation
dividing the lophophore nearly into two equal halves ; this is caused by the triangular
septum mentioned above. These halves correspoiul with the two arms of other Brachio-
pods. The lophophore [p. 500] is attached anteriorly and anterio-laterally to the mantle
lining the shell, postero-laterally it is attached to the free edge of the triangular plates ; in
the median postcn-ior portion it is continuous with the remaining body wall. In the median
line it is attached on each side to the free edge of the septum. The lophophore carries
round its margin a number of tentacles ; the number increases with the age, but is usually
from 70 to 100. "Within the bases of the tentacles a lip runs entirely round the lopho-
phore, forming a groove ; the mouth lies in the posterior median portion of this groove.
The remainder of the lophophore is composed of a membrane which covers some of the
viscera ; the centre of each half of this membrane is rather thickened and presents in
the fresh state an ill defined whitish patch. The tentacles usually lie ])ointing towards
the centre of each half, but they are often curved and sometimes coiled like a cork-
screw Around the edge of the lophophore, between the base of the tentacles and the

origin of the lip, there runs a canal in the substance of the lophophore . . . Thus the cavity
in the lophophore communicates with part of the body cavity. . . . The protrusion of the
tentacles [p. 501] is probably brought about by forcing in a perivisceral fluid, but their
retraction and coiling movements are probably occasioned by tlie muscular fibres which
lie in their interior.

" The mouth [p. 502] is a transverse slit in the median posterior part of the ciliated
groove ; it leads into a somewhat narrow oesophagus which lies against the posterior
curved border of the triangular septum. At the bottom of this border, the oesophagus
turns towards the posterior end of the animal and immediately enlarges into the stomach.
This is globular in shape and receives upon each side the opening of the liver. The
stomach narrows posteriorly and passes into a conical intestine which bends towards
the ventral shell between the two brood pouches, and ends between the occlusor muscles.
There is no anus.

" The liver [p. 503] consists of two branched glands lying one on each side of the

alimentary canal The blood is contained in a number of vessels which run iri'egu-

larly in the tissues of the body, but which chiefly lie in the mantle and that part of the
body wall lining the shell."

138

DR. T. DAVIDSON ON EECENT BEACHIOPODA.

Diagrammatic view of
the muscles of Argiope
(after A. E. Shipley).

" The muscles [p. 504] of Av^\o\)q {ClsteJla) consist of four pairs ; of these two pairs are
connected with tlie movement of tlie shell upon the stalk, tlie other two with closing and
opening the shell. Each of these last is composed of two parts
and is usually considered to rej)resent two distinct muscles, thus '"'

making the number six Of the two pairs of adjusters, which

are both inserted into the peduncle, one pair arises from each shell
(A'alve) (woodcut, fig. 14, d.ad and v.acl). The pair arising from the
dorsal shell has its origin opposite the commencement of the intes-
tine, and tlie muscles of this pair are close to each other, one on each
side of the median line ; they pass down and are inserted by a tendi-
nous cord which passes directly into the substance of the stalk. The
adjusters of the other shell have their point of origin a little nearer
the posterior border of the shell, and are rather larger, they also are
inserted into the stalk in a similar manner. The principal function
of tliese muscles is without doubt to raise and lower the animal upon

its stalk The occlusor muscles [p. 505] have two points of origin

upon each side of the m.edian line of the dorsal shell, one in front of
the other. They correspond with the two parts of the muscle which
were termed by Hancock the occlusor anterior and posterior. Their origin is external to
that of the adjustor muscles, and their anterior limit passes far into the two anterior lateral
divisions of the body cavity formed by the septum (woodcut, fig. 14, oc.m). The muscles
of each side which are at first quite distinct soon unite into a common tendon which takes
an obliquely downward direction, passing close vmder the central nervous system; and here
it is connected with the homogeneous substance supporting the chief ganglion on each
side of the oesophagus, and is inserted by an expanded extremity in the ventral shell just
to one side of the median ridge. The insertion is a little anterior to the posterior limit
of the intestine which lies between the two tendons. The division into two parts, of
the divaricators, is much less marked than is the ease with the occlusors. These
muscles arise, one upon each side of the median line in the posterior part of the ventral
shell, a little behind the insertion of the occlusors, they pass straight across and their
tendons are inserted into the most posterior part of the dorsal valve in the middle line
(woodcut, fig. 14, d.m). The axis upon which the shell turns joasses through the teeth
and sockets mentioned in the description of the shell, and this lies in front of the
insertion of the divaricator muscles ; hence a contraction of these muscles has the effect
of opening the shell- In Argiope [Cistella) all the muscles are unstriated.

" The peduncle of Argiope [p. 506] appears to be an unusually large development of the
homogeneous supporting substance which occurs so frequently in the body of Brachio-

poda The ovaries of Argiope p. 507] are of a bright brick red color, resembling

the red rays on the shell of Argiope cuneata Each ovary [p. 508] appears to be

foi'med of a membrane continuous with the body-wall When the eggs are ripe they

drop off into the body cavity, the capsule apparently bursting. In the body cavity they
are taken by the inner end of the oviduct and thus pass into the brood pouch."

DE. T. DAVIDSON OX EECENT BRACHIOPODA. 139

Mr. A. E. Shipley then goes on to describe and illustrate the diU'ercut stages of
embryonic development, and his descriptions agree Avith those given by Kowalevsky.
The few preceding extracts from Shipley's very instructive paper will enable the reader
to form a good idea of the character of the shell and the animal of Cistella neapolitana.

Subsequently to the publication of Mr. Shipley's researches, another able memoir
on a closely allied species was puljlished by M. A. Schulgin, to which Ave shall shortly
refer. As this Avriter confirms, in all essential points, the details given by Shipley,
Ave may consider the animal of Cistella to have been thoroughly and ably worked out.

78. Cistella cistellula, Searles Wood, sp. (I'late XXII. iigs. 1- 1.)

Tcrebrutula cisteUula, Scai-les Wood, Auu. & Mag. Nat. Hist. 1st ser. vol. vi. \\. 2."j,'J, 1811.

Aryiope cistcUula, Searles Wood, Suppl. to the Crag Mollusca, Pal. Soc. p. 170, pi. xi. figs, i u-il, 187 t.

Mciiathijiis clslcllula, Forbes & Hauley, Brit. Moll. vol. ii. p. 361, pi. ivii. fig. 9, 1850.

Argiope cistdlulu, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 373, 18,"i2; i'roc. Zool. Soc.
1852, pi. xiv. fig. 28; Monogr. Brit. Tert. Brack, i., Pal. Soc. p. 10, pi. i. fig. 13, 18."')3; Ann. & Mag.
Nat. Ilist. ord ser. vol. viii. p. 40, 18G1 ; Tort. Suppl. Brit. Foss. Bracli. vol. iv. p. (!, (il. i. fig. 2, 1874;
E. Deslongclianips, Bull. Soc. Linu. Normaudie, vol. iii. p. 120, 1858.

Cistella cistellula, Woodward & Ciray, Cat. of Brachiopoda iu the Brit. ^lus. p. Ill, 1853 ; 11. & A.
Adams, Genera of Recent Mollusca, vol. ii. p. 581, 1858.

Argiope cisiellida, E. Suess, Ueber die Wohnsitze der Bracliiopodeu, Siizuiigsb. k. Akad. Wisseu^cli.
Wien, Bd. xxxvii. p. 215, 185!) ; Gwyn JeftVeys, Brit. Couch, vol. ii. p. 19, pi. i. fig. 2, 18G3, and vol. v.
p. 1G4, pi. xix. fig. 4, 18G9; Further Cleaniugs of Brit. Couch., xVnu. & Mag. Nat. Hist. 3rd ser. vol. iii.
p. 43, pi. ii. fig. 8, 1859 ; Proe. Zool. Soc. 1878, p. 410.

Cistella cistellula, Dull, Aiuor. Jouru. Conch, vol. vi. p. 14G, 1870; Proe. Acad. Nat. Sci. Phila-
delphia, 1873, p. 191.

Terebratulu [Aryoipe] cistellula, Lovell lleevc. Couch. Icon., jMouogr. Ter. pi. x. fig. 46, 18G1 ; Ann.
& Mag. Nat. Hist. 3rd ser. vol. vii. p. 18G, 18G1.

Argiope cistellula, P. Fischer, Brachiopodes des Cotes oc(5aniques de France, Jouru. dc Couch, vol. xix.
p. 104, 1871 ; and Actes Soc. Liun. Bordeaux, vol. xxix. p. 173, 1874.

Shell very small, variable in shape, often squarely transversely oblong, broader than
long, or subpeutagoual and as long as wide ; hinge-line nearly straight, and often as
Ions as the 2:reatest breadth of the shell : cardinal extremities rounded or more often
extended into sharp angular extremities ; lateral margins rounded, front gently indented.
Dorsal valve semicircular, moderately convex, lateral sides of umbo auricular, longitu-
dinally divided by a mesial depression commencing at a short distance from the umbo
and extending to the front. Ventral valve deeper than the dorsal one; beak. slightly
incurved, often worn by attrition ; foramen large, incomplete, margined anteriorly by the
umbo of the opposite valve, and laterally by small deltidial plates ; beak-ridges sharply
defined, leaving between them and the hinge-line a flattened triangular area. Colour dull
tawny yellow or light yellowish brown. Surface smooth, marked with line concentric
lines of growth. Shell-perforations rather large. In the interior the teetli are strong,
sockets not very deep. Hinge-plate long, not very wide. Septum submarginal, promi-
nent anteriorly ; loop formed of two semicircular lamellae, attached first to the base of
the hinge-plate and then to the anterior extremity of tlie septum, and more or less
confluent with the valve. Brachial appendages yellowish brown. Cirri few and thick ;

SECOND SERIES. — ZOOLOGY, VOL. IV. 19

140 DE, T. DAVIDSON ON RECENT BEACHIOPODA.

occlusor and retractor muscles very large and powerful. Length 1 line, breadth Ij line,
depth 1 line.

Hub. East Shetland, Skye, County Antrim (Gwyn Jeffreys) ; Moray Firth (Dawson) ;
Dublin Bay (Walker), Belfast Bay ; Exmouth (Barlee and Clark) ; off Guernsey (where
Dr. Leskis found more than 200 specimens on a single stone brought up from a depth of
20 fathoms); off Weymouth (Damon) ; Sardinia (Verany) ; Etretat, Normandy ; S.W. coast
of Erance, Cape Breton (Landcs), Hendage, Basses-Pyrenees, in 32 to 45 fathoms
(P. Eischer).

Fossil. Kirkoen, near Christiania (Sars) ; Coralline Crag, Sutton (Searles Wood), not
abundant.

Obs. The discovery of this interesting little Brachiopod is due to Mr. Searles Wood, who
mentioned it under the name of Terebr^atuJa cistellula in his ' Catalogue of the Crag Mol-
lusca ' in 1841, and it was dredged in the living state by Dr. Gwyn Jeffreys seven years
later. Eorbes and Hanley give a good description of this shell as found in the recent state
in their valuable work on ' British Mollusca.' It is there stated that a few specimens
had been found in 40 fathoms of water by Mr. Jeffreys and Mr. Barlee while dredging off
Skye ; also in 30 fathoms off Croulin Island, near Skye, by Mr. MacAndrew ; and on the
Haaf, or deep-Avater fislung-grounds of Zetland, by Mr. Barlee. Dr. Gwyn Jeffreys
observes, in his ' British Conchology,' p. 21, that this shell may be easily distinguished
from Argiope iieapolitana " in being only half the size and more convex, in the foramen
being much larger, and in the inside margin of the upper valve being slightly and closely
crenulated, instead of having rather strong and distant tooth-like notches, which is the
case in A. neapolitana.'"

To this species several malacologists have referred the Terebratula lunifera of Philippi,
while others have referred that shell to the Plati/dia anomioides. As much uncei'-
tainty prevails about the matter, I have preferred, provisionally, to leave T. lunifera
among the doubtful species of Plafi/dia{?). In 1852 I published a figure showing the
labial appendages and muscles from a dried specimen, as well as the two-lobed loop.

79. CiSTELLA WooDTVARDiANA, Davidson, sp. (Plate XXII. figs. 7, 7c.)

Arg'wpv IJoodwardimin, Davidson, Proc. Zool. Soc. 18G6, p. 103, pi. xii. fig. 4.

Cistella IJ^oodicardiana, Dall, Amer. Journ. of Conch, vol. vi. p. 146, 1870; and Proc. Acad. Nat.
Sci. Philadelphia, 1873, p. 195.

Shell very small, somewhat pentagonal, indented in front. Dorsal valve semicircular;
hinge-line straight, as long as the width of the shell, moderately convex, but divided
into two lobes by a deep median sulcus. Ventral valve deeper and more convex than the
opposite one, and with a longitudinal groove along the middle ; beak very prominent ;
area acutely triangular ; foramen large and incomplete, margined by the umbo of the
opposite valve and laterally by small rudimentary deltidial plates. External surface
smooth, whitish yellow, with a few red patches arranged in interrupted lines radiating
from the beak. The shell is also marked with numerous concentric lines of growth.
In the interior of the dorsal valve the loop is two-lobed, adhering to a central sub-

DE. T. DAVIDSON ON EECEXT BEACHIOPODA, 141

marginal elevated septum. Sliell-structure i:)unctate. Propoi-tions variable ; the largest
specimen measured — length 2.j lines, breadth 2 lines, depth If lines.

Hab. This species Avas obtained at a depth of GO fathoms, off the north-east coast of
Jamaica, by Lucas Barrett.

Ohs. I published this description in 1SG6, and have never seen any specimens besides
those obtained by Mr. Barrett. Cistella JFoodicurdiaiia is a stout little shell, and
differs from its congeners in shape as weU as in its smooth and spotted surface.

80. Cistella cuneata, Eisso, sp. (Plate XXII. figs. 30-31.)

Terebratiila ciineata, llisso, Hist. Nat. Europe meridionale, t. iv. p. 388, pi. 4. fig. 179, 1826.

Terebratulu Solduniana, Eisso, Hist. Nat. Europe meridiouale, t. iv. p. 389, pi. 4. fig. 178, 182(5.

Terebratula cuneata, de Blainville, Diet. Sci. Nat. t. liii. p. 143, 1828.

Anomia Peru, ]\Iuhlfcld, A^erhandl. d. Gesellscli. naturforsch. Frcunde, Berlin, i. p. 205, 1829.

Terebratula cinxuitii, Pliilippi, Enum. Moll. Sicilise, vol. i. p. 90, pi. vi. fig. l;5, 183G ; E. Forbes,
Eeport ou the ^lollusca of ^Egean Sea, Brit. Assoc. Report for 1843, p. 1G5.

Terebratula pera, Kiister, Conch. -Cab. vol. vii. p. 30, pi. 2 b. figs. 14-17, 1843.

Orthis Peru, Pliilippi, Euum. Moll. Siciliie, vol. ii. p. 69, 1844.

Terebratula cuneata, G. B. Sowerby, Thes. Concli. i. p. 355, pi. Ixxi. figs. 83 & 84, 184G.

Ortliis Pera, O. G. Costa, Fauna del regno di Napoli, p. 37, pi. iii. bis, fig. 1, 1851.

Argiope cuneutu, Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix. p. 373, 1852; and Proc. Zool.
Soc. 1852, pi. xiv. fig. 27 ; Woodward[& Gray, Catalogue of BracLiopoda in Brit. Mus. p. 114, 1853 ; E.
Suess, Ueber die Wolinsitze der Bracbiopoden, Sitzungsb. k. Akad. Wissenseh. Wien, p. 21 1, 1859.

Terebratula [Argiope) cuneata, Lovell Eceve, Concb. Icon. pi. x. fig. 44, 1801 ; Ann. & Mag. Nat.
Hist. 3rd ser. vol. vii. p. 185, 1861.

Terebratulu cuneata, Verany, Zool. des Alpes Maritimes, 1862.

Arr/iope cuneata, H. C. Weinkauff, Die Coneb. des Mittelmccres, vol. i. p. 288, 1867.

Aryiope Peru, S. Brusina, Moll. Dalmati, p. 47, 1800.

Terebratula cuneata and T. Soldaniana, Davidson, Notes on some Recent Mediterranean Species,
Ann. & Mag. Nat. Hist. 4tb ser. vol. iii. p. 374, 1809.

Orthis pera, Terquem, Coquilles de Corse, p. 99.

Aryiope cuneata, Montcrosato, Cat. delle Coq. Mediterranea, 1875; G-nyn Jeffreys, Proc. Zool.
Soc. 1878, p. 410; Sdmlgin, Zeitschrift i'iir wissenseh. Zool. Bd. xli. p. 121, pi. viii. fig. 3, 1885;
A. E. Shipley, On the Structure and Development of Aryiope, Mittheilungen a. d. Zool. Station zu
Ncapcl, Bd. iv. p. 495, 1883.

Shell very small, somewhat transversely semicircular, obtuse posteriorly, slightly
indented in front, rounded laterally, wider than long. Iliuge-line straight, about as long
as the greatest breadth of the shell; cardinal angles gently rounded. Dorsal valve semi-
circular and very gently convex. Ventral valve deeper and more convex than the dorsal
one ; beak tumidly produced, slightly incurved and truncated l)y a very large, broad,
incomplete foramen, thickened posteriorly, anteriorly margined by the umbo of the
dorsal valve, and laterally by small rudimentary deltidial plates ; beak-ridges sharply
defined, leaving betAveen them and the hinge-line a widish triangidar flattened space.
Surface of valves marked with from six to eight simple, rather flat, rounded radiating ribs,
with interspaces of nearly equal breadtli, three or four on each side of a rather wide
median groove ; ribs corresponding in both valves. Colour white, or bright yellow, tinted

19*

142 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

with light-brick or rose-red between the ribs ; shell-structure punctate. Length a little over
1 line, breadth 2 lines, and less than 1 line in depth. In the interior of the dorsal valve
the hinge-plate is very broad and narrow ; from under its centre a long narrow mesial
septum proceeds to within a short distance of the front margin, which acquires height as
it nears its anterior extremity. The principal lamellse of the loop, first attached to the
base of the hinge-plate by a half-circle, afterwards attach themselves to tlie sides of the
anterior extremity of the septum. Margins of the shell crenulated. In the interior of the
ventral valve a short mesial ridije extends to half the leno>th of the valve under the
posterior thickened edge of the foramen.

Hah. Cistella ciineata occurs in different j)laces in the Mediterranean. In the Bay of
Naples ; iEgean Sea at a depth of from 28 to 69 fathoms (Forbes) ; near Villafranca. To
a white variety found near the coast of Sicily Dr. Gwyn Jeffreys has given the varietal
name oipentalaria. It has been found off the Canaries in 28 to 200 fathoms ( MacAndrew) ;
off Corsica (Terquem), Sardinia (Cantraiue), Dalmatia (Brusina).

Philippi mentions it as fossil at Tarent.

Obs. In the ' Proceedings of the Zoological Society of London ' for 1852 I gave an
enlai'ged figure, showing the interior of both valves in a dried specimen given to me by
Prof. E. Porbes in 18.51. It shows the fringed labial appendages of a yellow colour, the
position of the mouth, and of the adductor, cardinal and pedicle muscles.

Cistella cimeata bears some external resemblance to Argiope decollata, but differs from
it generically, on account of its bilobed loop which is attached to a single submarginal
septum. It is also a much smaller shell, with fewer and simple ribs tinted with red
in their interspaces.

In his paper on the Mollusca procured during the ' Lightning' and ' Porcupine ' Expe-
ditions (Proc. Zool. Soc. of London, 1878, p. 410), Dr. Gwyn Jeffreys says : — " I have
been favoured by Prof. Seguenza with an opportunity of examining his unique specimen
of Argiope biplicata from the Straits of Messina, and of comparing it with an extensive
series of A. cimeata and its colourless variety. The result of such examination and com-
parison, as regards both the outside and inside, compels me to consider the specimen an
abnormal form of A. cuneata!'

I would, however, have almost considered it a malformation of Cistella neapolttana, for
some specimens of the last-named shell sometimes possess four rounded ribs with a Avide
mesial interspace, as in Seguenza's specimen. Cistella cimeata has received three or four
specific names, but that of cimeata seems to be the oldest. While at Nice, in 1869, I
was able to examine llisso's types of Terebratula cimeata and T. Soldaniana, and found
them referable to a single species, and this view was subsequently confirmed by Dr. Gwyn
Jeffreys.

81. Cistella lutea, Dall. (Plate XXTII. figs. 5 & 6.)

Cistella Barrettiana, Dall, Amer. Jouni. of Condi, vol. vi. p. 1-16, 1870.

Cistella {1 Barretti(t)ia var.) lutea, Dall, Report on the Brach. dredged by the United States Coast
Survey Exped., Bull. :\Ius. Comp. Zool. vol. iii. p. 20, pi. i. figs. 5 & 6, 1871.

Cistella lutea, Dall, Moll, of the ' Blake ' Exped., Bull. Mus. Comp. Zool. vol. xii. p. 203, 1886.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 143

Shell small, transversely oval, wider than long- ; hinge-line straight, rather less than the
breadth of the shell, sides and front rounded. Dorsal valve semicircular, very little
convex, somewhat flattened. Ventral valve deeper than the dorsal one, Avith a slightly
marked depression extending from the beak to the anterior margin ; beak bent backwards
and truncated by a large incomplete foramen, xxsually much eroded, margined ante-
riorly by the umbo and laterally by very small rudimentary dcltidial plates ; area
triangular, flat, and smooth. Colour light brownish white, with about twelve radiating
ribs in each valve, of which five or six are smaller and interpolated between the longer
ones. In the interior of the dorsal valve a large, much elevated mesial septum is
present, denticulated anteriorly, forming nodules and iiotches on its upper edge, the
whole having a subtriangular form, somcAvhat resembling an open fan. The loop consists
of tAvo bands, or lamella?, attached to the hinge-margin and afterAvards to the sejitura on
each side about its middle and close to the shell. Cardinal plate, or hinge-plate, absent ;
area behind the muscular disk somcAvhat excavated. Length 3 lines by 3J in breadth.

Hah. Tortugas, in a depth of 30 to 43 fathoms (Pourtales). Ofl^ Havana, 80 to 127
fathoms (Sigsbee) ; Barbados, 100 fathoms, ' Blake ' Exped. (Dall).

Obs. We are indebted to Mr. TTilliam H. Dall for the first description of the animal of
Cistella (C. litlea), Avhich he published in 1871, prior to Ivowalevsky's admirable
description of the animal of Cistella NeapoUtana in 1873, and that of C. KoicalevsJdi by
Schulgin in 18S4. Dall says (/. e. p. 20) : — " Muscular impressions much thickened,
forming two rather concave disks. . . . The anterior portion of the apophyses is
more posterior than in C. NeapoUtana, and the margin is not granulated as in that
species. It Avould seem from Mr. Davidson's figures that the loop of Cistella Barrettiana,
Dav., is more anterior than in this species ; the latter being also unprovided with the
posterior extension of the septum seen in the figure of the former, and being, moreoA'er,
entirely destitute of the red markings between the ribs ..... It is possible that the
present species, C. Anfillartim and C. Barrettkma, are forms of one species, in which case
the last name has priority."

[_L. c. p. 22.] " I have not met Avith much success among these small species in the use
of acid in dissolving away the shell from the animal. . . . The brachia in this and the other
species oi" the genus are arranged around the edge of a broad membrane, Avhich covers the
concavity of the shell, like a drumhead. The loop of the drum is represented by the apo-
physes. The brachia diS"er from the same organs in the Terebnitulina; in being arranged
in a single series instead of a double one. Of this there can be no doulit, it is very evident
upon a casual inspection, and is entirely confirmed by careful dissections. In this species
the drumhead membrane is divided into two lobes by the septum. The edges of these lobes
are fringed Avith the brachia. . . . They are usually curled up in front and on each side,
Avhile those Avhich are situated behind the mouth are longer than the others, and usually
lie smoothly over them, extending forward without any marked curve, pointing toAvards
the anterior margin of the shell, and extending clear over the central membrane, even
beyond the posterior edge of the septum. The brachia are covered Avith an epithelium
furnished Avith cilia, are tubular, and communicate Avith a series of brachial channels,

144 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

which did not appear to differ from those of Waldheimia as described by Hancock,
as far as I was able to discover. The great brachial canal was rendered conspicuous by
a band of cartilaginous substance which seemed to form its external covering, or rather
beneath which it was situated, and Avhich was longitudinally striated. The external
edge of the membranes, between which the apophyses were formed, was directly attached
to the pallial lobes at the points where the apophyses are attached to the muscular disks
of attacliment already described. On either side of this attachment, however, was a
kind of pocket, opening externally, where the brachial and pallial membranes did not
coalesce ; and, there being one on each side of the point of union, there were conse-
quently four in all, two on each side of the septum. Tiie drumhead membrane, covering
the space inside of the brachia, was translucent white or opalescent, and quite thick and
tough towards the middle of each lobe."

[i. c. p. 23.] " I am inclined to think that an eri'or has been perpetuated in regard to
the position of the mouth of Megathyris decollata. It has been figured and described by
Woodward as being of a circular form, and situated in the midst of the drumhead membrane.
It is certainly not so situated in Cintella ; and I do not believe that it is in Megathyris,
though I have only seen dry specimens. In the present species it is placed, as in all the
TerehratuUdcs, at the back of this nieml)rane, just in front of the posterior junction of the
brachia, and at the bottom of a deep transverse groove which is of a stout membranous con.
sistency, and the two sides of which, for convenience' sake, I have called the lips {labia). In
the present species the oral groove is situated far back and close to the brachia, which are
exceptionally long behind it, as already described. It is, in fact, entirely hidden by them
until they are laid back. The groove is very long and quite deej), the entrance to the
oesophagus being trumpet-shaped and flattened transversely. Were the brachia disposed
as in Woodward's figure, the oral groove would be hidden. I am disposed to think that
this was really the case in the specimen figured, and that the extraordinary circular
motith there figured was an accidental lesion of the dry tissues, which might easily be
taken for a mouth of so small an animal. The labia, in all the Brachiopods I have
examined so far, have invariably exhibited a tinge of darker colour than the surrounding
tissues. The present case forms no exception. The posterior lip presents a small promi-
nence in the median line, and the anterior lip a small emargination or concavity below
this prominence. This structure is also common to all the Brachiopods I have examined.

"The oesophagus is wide, transversely flattened, with thin walls, and of an orange
color. It enters the stomach nearly at a right angle, without much dilation. The
stomach is oval with thicker and firmer walls ; the inner lining appearing slightly villous
and rugose. The intestine is not diiferentiated from the stomach on the lower side, but
on the upper side a deep groove occurs at the juncture. The canal is stout and thick at
its lower extremity, tapers slightly, and terminates in a somewhat bulbous, Init pointed
csccal extremity, attached to the perivisceral membrane. The various membranous bands
which support the alimentary system present no differences from the homologous struc-
tures in other species of TerehratuUdce. The stomach was filled in each case with a
yellowish flocculent matter. The hepatic lobules resembled those of other species, entering

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 145

tljc stomach by two ducts on each side, of which the anterior were the larger. They
did not extend over or cover the sides of the intestine."

[L. c. p. 2jf.] "The licart is extremely small and difficult to find. It is situated lower
down than in most species, and between and hidden by the hepatic lobules. It is nearly
spherical. No accessory pulsatile vesicles were found, after close scrutiny.

" The ovaries differ in appearance from those of JFaldhelmia and Terebmlnllna. They
hang like a frill or puckered ribbon-like lamina from the pallial membranes, and form a
simple loop on each side of each valve. Those of the hgemal (dorsal) valve Avere most
developed. The ends of the loops extended into the great pallial sinuses. The rounded
granules which studded the frills were of two kinds. Those at or near the extreme edge
were of a pellucid deep brown hue, while those closer to the pallial membrane were mostly
of a pale yellowish color, and quite opaque. The oviducts are very inconspicuous and
not easily found. They are situated in the usual position, but exhibit only a very few
short folds, and the external opening directly in the midst of them, instead of being at
the end of a rather long duct, as in other forms. There are only two of them. They do
not appear to be attached to the intestine or mesenteries, but lie flatly upon the parietes.
The pallial sinuses are comparatively insignificant in this species, being very narrow,
almost linear, channels with few branches. A few spicula3 were observed in some of them.
The margin of the mantle is perfectly plain, without seta3, and adhering closely to the
shell. Yet the circumpallial muscular band is m;ich broader than usual, and strongly
marked. When torn from the shell, the csecal prolongations of the mantle were beautifully
shown. They wei'e often bifurcate and occasionally had three or even four branches.

" The punctate structure of the shell was very coarse. Even the crura and laminae
of the apophyses were punctate. The nervous system was not traced out ; but the
oesophageal ganglia presented no special peculiarities.

"The border of the mantle appeared to be ciliated. The peduncle, so wide and short
as to resemble a mere muscvilar disk, was strongly attached to the shell by the peduncular
muscle, beside which a broad tendinous band appeared to pass entirely across, in front
of the dorsal adjustors (posterior retractors of Owen), giving an additional solidity and
firmness to the attachments of the peduncle. The extremities of all the muscles were
very much enlarged and thickened, while their median portions were slender and
tendinous. No striated fibres were observed."

82. CiSTELLA Bakrettiaxa, Davidson, sp. (Plate XXIII. figs. 1 & 2.)

Argiope Bmrettiana, Davidson, Proc. Zool. Soc. 1866, p. 103, pi. xii. fig. .3.
Argiope Antillarum, Crosse & Fischer, Journ. de Conch, vol. xiv. p. 270, pi. viii. fig. 7, 1866.
Cistella Barrettiana, Dall, Amer. Journ. of Conch, vol. vi. p. 14G, 1870; and Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 193.
Cistella [1 Schrammi, var.) ruhrotincta, Dall, Bull. Mus. Comp. Zool. vol. iii. p. 19, pi. i. fig. 6, 1871.
Cistella Barrettiana, Davidsou, var. rvbrotincta, Dall, ]\Ioll. 'Blake' Exped., Bull. Mus. Comp. Zoiil.
vol. xii. p. 203, 1886.

Shell small, somewhat subpentagonal, wider than long; dorsal valve semicircular.

146 DK- T. DAVIDSON ON RECENT BRACHIOPODA.

slio-litly indented in front ; liinge-line straight, as long as the hreadth of the shell, forming
acute angles at its junction with the labial margins of the valves. Valves vmequally
convex. Dorsal valve very gently convex, rather flat, with a shallow longitudinal depres-
sion along the middle. Ventral valve convex, with a rather deep mesial sinus, correspond-
in"- to the one in the dorsal valve; beak and area sloping backwards, forming an obtuse
anc-le with the plane of the dorsal valve. Foramen very large, incomplete, margined
anteriorly by the umbo of the dorsal valve, and laterally by rudimentary deltidial plates.
Surface of valves traversed with from eight to tAvelve rounded ribs, corresponding in
both valves, with interspaces between them of almost equal breadth. Colour pale yellow,
with scarlet interspaces ; surface marked with punctuations clearly visible to the eye in
a o-ood lia'ht. In the interior of the dorsal valve the apoj)hysary system consists of a
bilobed ribbon-shaped lamella, originating at the base of the sockets, which after forming
half a circle on each side, adheres to a central prominent submarginal septum, the
lamellae forming the loop being also partly confluent with the valve. Proportions
variable. Length 3 lines, by a little more than 1 lines in breadth.

Hah. North-east coast of Jamaica in a depth of 150 fathoms (Barrett). At Guada-
loupe in from 200 to 250 fathoms (Crosse). Dredged in 70 fathoms off E,io de Janeiro,
Brazil, by the captain of the English steamer ' Norseman,' in lat. 21° J^S' S., long. 40° 3' W.
These specimens were obtained attached to corals brought up by the grappling-irons, and
sent to me by Mr. E.. Ptathbun. Dredged also by M. de Pourtales west of Tortugas in
30 to 43 fathoms ; Sand Key, 80 fathoms ; St. Vincent, 95 fathoms ; Tortugas, 43
fathoms ; otf Grenada, 115 fathoms ; Barbados, 100 fathoms ; off Havana, 450 fathoms
(Sigsbee), Yucatan Strait, 641 fathoms, ' Blake' Exped. (Dall).

Obs. This fine species of Clstella approaches most nearly in general appearance to the
Cistella cnneata, Eisso, but is a much larger species and possesses, when full-grown, a
o-reater numl)er of ribs. In external shape it bears likewise some resemblance to Arglope
decollata, from which, however, it can Ije at once distinguished by its two-lobed loop and
single submarginal septum. It varies someAvhat also in shape as well as in the number
of its ribs, some specimens being as long as wide when quite young. In a letter dated the
22nd of March, 1870, Mr. Crosse writes me that in all probability his Argiope antillarum
is a synonym of Cistella Barrettiana, but that he considers his C. Schrajnud to be a dis-
tinct species. I have also, through the kindness of Mr. Dall, been able to examine the
lype of his O. ruhrotincta, and I believe it to be a synonym of C. Barrettiana. Erom
Mr. Dall's description it would seem that it is of a pale yellow colour, with brilliant
scarlet interspaces, and agrees in shape and character with typical examples of C.
Barrettiana. " Septum triangular, extending from the hinge margin to the anterior
border of the shell. Most elevated point, forming the apex of the triangle in the middle
of the valve, rather bulbous and of a red colour. Anterior slope of the septum to the
border of the sheU, straight without nodules ; this part of the septum is thin and even.
Posterior slope of the septum irregularly concave, tliick, and nodulous, tapering to a
point at the hinge-margin." The size and extent of the transverse plate of the septum
varied in different specimens.

DR. T. DAVIDSON OX EECENT BEACHIOPODA. 147

Uncertain Species.

83. ARGiorK GLOBULiFOEMis, Scliulgiii. (Plate XXII. fig. 28.)

Argiope globuliformis, Scliulgin, Zeitscbr. f. wiss. Zool. Bd. xli. p. 1:21, pi. viii. fig. 2, 188 i.

Shell small, ellipsoid, globular ; valves smooth, inflated, of a yellowish colour ; beak
not very projecting, wide ; foramen incomplete, transversely oval. In the interior of the
dorsal valve there are three submarginal ^epta. In the ventral valve one low median
septum. Diameter 7 millim.

Ilab. Obtained by Sehulgiu on stones off Sardinia, and near the islands of Ilyeres ;
it was not found at Villafranea.

Obs. I have never seen this shell and have no further knowledge of it tliau Schulgin's
very brief description and figure affords. It is said to have tlu-ee submarginal septa in
the dorsal valve, and must consequently be placed in the genus Ai'giope.

81. Argiope Barroisi, Schulgin. (Plate XXII. fig. 29.)

Argiope Barroisi, Schulgin, Zeitschr. f. wiss. Zool. Bd. xli. j). 1:2"J, pi. vii. fig. 4, 1884.

Shell small, squarely transversely oblong, wider than long ; hinge-line straight, less
than the breadth of the shell. Valves moderately convex, ornamented with from eight
to eleven rounded ribs. Colour light yellowish orange ; interspaces between ribs bright
red. Beak moderately produced ; foramen large, circular, incomplete, margined ante-
riorly by a part of the umbo of the dorsal valve. In the interior of the dorsal valve there
are three high submarginal septa, and a single low one in the ventral valve. Breadth
3 "6 millim. ; length 3 millim.

Hub. It oecui's frequently on Posidonia and upon stones at Villafranea, along
w'ith Cistclla Kowalevskii at a depth of 30 metres ; also off Sardinia, Xaples, and tlie
islands of Hyeres.

Obs. I have never seen this shell, and know nothing more of it than is contained in
Schulgin's brief description. Ilis figure does not quite satisfy me. As it is said that
three septa exist in the dorsal valve, it is an Argiope.

85. CiSTELLA Kowalevskii, Schulgin, sp. (Plate XXII. figs. 26 & 27.)

Argiope Koti-alevskii, Schulgin, Zeitschr. f. wiss. Zool. Bd. xli. p. \2\l, pi. viii. figs. 5-9 & 12, pi. ix.
figs. 14-18, 188L

Shell very small, from 3 to 8 millim. in length by 3 millim. in breadth, heart-shaped,
broadest and rounded anteriorly, tapering somewhat posteriorly. Valves gently convex,
thin, shining, and sharp at their edges, marked with a few concentric lines of growth and
widely separated punctures ; beak short, triangular, both it and the umbonc of the opposite
valve excavated for the passage of the cyUndrical-shaped pedimcle. In the interior of the
dorsal valve one short thick submarginal septum ; in the ventral valve a thin, low, long
septum. Colour yellow,

SECOND series. — ZOOLOGY, VOL. IV. 20

148

DR. T. DAVIDSON OX EECENT BRACHIOPODA.

FiK. 15.

ILah. Foimd by Herr M. A. Scliulgin alone or in groups on Posklonia ; off Sardinia,
Villafranca, and off the islands of Hyeres.

Obs. I have never seen this small shell. Schulgin
gives two figures which seem to me rather dissimilar ;
we will, however, take the illustration in his pi. viii.
fig. 5 as his type, as it differs in several particulars
from Cistella neapoUtana. Schulgin describes and illus-
trates the shell and its animal with much care and minute-
ness in the memoir above quoted ; but his description
agrees so nearly witli that of Cistella neapolitana, pub-
lislied one year before by Mr. Shipley, that I must
refer the reader to Herr Schulgin's memoir, and content
myself by reproducing in PL XXII. fig. 26 one of the
author's most instructive illustrations. Schulgin seems to
have discovered the presence of some sense-organs situated
in the body-wall just behind the chief or suboesophageal
nerve-ganglion ; but this requires confirmation, for A. E. Muscular arrangement in Cistella
Shipley saw notliing of them in the allied species he studied Sowalevskii (after ScMgin).
in Naples. The arrangement of the muscles in C. Ko- rtc^.", adjuvator ventralis ; rfv.i', di-
loalevskii is quite similar, as might be expected, to that varicator ventralis ; oc.6, ocelu-
described by Mr. Shipley in Cistella neapolitana.

sor biceps ; ad.d, adjuvator dor-
salis ; </v.d, divaricator dor-

salis.

86. Cistella Schkammi, Crosse, sp. (Plate XXIII. figs. 3 & 4.)

Argiope Sclirammi, Crosse & Fischer, Journal dc Concli. vol. xiv. p. 269, pi. viii. fig. 6, 1806.
Cistella Schrammi, Dall, Amer. Journ. of Conch, vol. vi. p. 146, 1871, aud Proe. Acad. Nat.
Sci. Philadelphia, 1873, p. 194.

Shell very small, transversely subpentagoual, wider than long, indented in front ;
hinge-line straight, as long as the greatest breadth of the shell, cardinal extremity
prolonged and acutely angular. Dorsal valve very gently convex, with eight rounded
ribs, and a very broad median depression between the two central pairs. Ventral valve
rather deeper than the dorsal valve, with a similar number of corresponding ribs, and
wide depressions between the central ones ; beak bent backwards, almost straight, area
triangular, foramen large and incomplete, margined anteriorly by the umbo, and by two
small lateral deltidial plates. Colour yellowish or pale orange, sometimes tinted with
red. Length 1 line, lu'eadth 1^ line.

Sab. Dredged, associated with Cistella Barrettiana (C. antiUariim, Crosse), off Guada-
loupe, at a depth of from 200 to 250 metres, by the Italian brig ' Icilia.'

Obs. Thanks to the kindness of M. Crosse, I have been able to examine and draw his
type. I have also a rather larger specimen from Tortugas. The matei-ial at hand has,
however, been so small that I can say nothing j)ositive with respect to the specific
claims of Cistella Schrammi.

DE. T. DAVIDSON ON EECENT BRACHfOPODA. 149

87. CiSTEi.LA (?) LUNIFERA, Pliilippi, sp. (Plate XXII. figs. 5 & 6.)

Terebratulu Imi'iferu, Pliilippi, Eiium. Mollusc. Siciiiaj, vol. i. p. '.)", tab. vi. figs. IG a~f, 1<S36.

Orthis luuifera, Costa, Faima del regno di Napoli, p. 40, tav. iii. bis, figs. 3 a, b, & I, 1851.

Morrisia luniftra, E. Suess, Uchor die Wolinsitze der Bracliiopodcn, Sitzuugsb. k. Akad. Wisscnseli.
Wien, 13d. xxxvii. p. 212, 1859.

Aryiope [Tcrebratula) lunifera=T. fw/eZ/M/tt, Montcrosato, Nuova Ku vista dellc Conchy. Med., Atti del
Aecad. Palerruitaua di Scieiize, 1875.

Terebratula (Morrisia) lunifera, L. Reeve, Couch. Icon. pi. x. fig. II, 18()1.

Morrisia Ituiifera, Weiukauft', Die Couch, des Mittclmecres, vol. i. p. 288, 18G7.

Aryiope liotiferu, Gwyn Jeti'reys, Mediterranean iloUusea { = A. cislcllulu), Ann. & Mag. Nat. Hist.
4th ser. vol. vi. p. G7, 1870.

Shell small, length aud breadth half a line, thin, hyaline, somewhat orhicular, broadest
anteriorly. Dorsal valve very gently and uniformly convex, somewhat compressed, very
slightly indented at the umbo and at the frontal margin. Ventral valve gently convex ;
beak short, slightly incurved and truncated by a rather large incomplete foramen ; beak-
ridges sharply defined, leaving between them and the hinge-line a narrow triangular space.
Surface smooth, puckered near the margin, and traversed by fine concentric lines of
growth. Colour light yellowish white. A small submarginal septum rises in the
interior of the dorsal valve. On each side of the mouth the labial appendages form a half-
circle and do not apparently occupy much more than a third of the interior of the shell.

Sab. Mediterranean Sea, off the African coast,

Obs. Much uncertainty has prevailed Avith respect to the genus to which this so-termed
species should be referred. It was described and figured in 1836 by Pliilippi as
follows : —

" T. testa minima ; subcordata, compressa, punctata, margine frontali subemarginato,
foramine incomplete, sceleto interne e lamella semilunata obliqua versus frontem aperta
constante. Specimina duo zoophytis inhaerentia inveni. Testa minima f'" louga, V"
lata, •!'" alta, cordata subpentagona, margiue frontali emarginata, parum convexa, con-
vexitate maxima in cardinis regionc, v. fig. c. Sub lente fortiori superficies punctis
minutis elevatis per series radiantes dispositis, aliisque minimis, impressis, densissimis
obsita. Area angusta satis elevata, foramen magnum iucompletum. Dcltidium distin-
guere non potui. Sceleton internum lamina obliqua semilunaris ad frontem prona et
aperta, v. fig. IG a et e. Color testae albidus." Philippi gives six figures of his little
shell ; in fig. a he draws a submarginal single septum as in Cistella, and he speaks of
a loop in the shape of a half-circular lamella.

The form is, therefore, as the Marquis of Monterosato and Dr. Gwyn Jeffreys suggest,
more nearly related to Cistella than to Flatijdia. Costa, in his ' Fauna del regno di
Napoli,' describes and figures some of the soft parts of the animal, from a specimen which
he says belonged to Philippi's species, which occurs off the shore of Trapani, as well as
near the coast of Africa. He points out the differences between it and Flatydla anomi-
oides. The hinge-line in the dorsal valve is entire and not scooped out, as in the last-
named species, for the passage of the peduncle, and its interior is quite difierent from
that of Platydia.

20*

150 DE. T. DAVIDSOX ON RECENT BRACHIOPODA.

The Marquis of Monterosato and Dr. Gwyn Jeffreys would consider the Cistella
cistellula of Wood to he a synonym of C. Inniferax hut this identification seems to he
lancertain, and new material must he examined and compared hefore the matter can he
regarded as definitely settled.

Uiicertam Genus and Sjwcies, 1859.
(The characters of the genus are given under Gioynia capsula. One species only known.)

88. GwYNiA CAPsULA, Gwyn Jeffreys, sp. (Plate XXI. figs. 28 a, b, c, & 29.)

Terebratula capsuhi, Jeffreys, Ann. & Mag. Nat. Hist. 3rd ser. vol. iii. p. 43, pi. ii. figs. 7(t, b, IS.jO.

Gwynia capsula, King, Proc. of the Dublin University Zool. & Bot, Assoc, vol. i. p. 258, -woodcuts,
figs. 1-5, 1859.

Arffiope capsula, Gwyn Jeffreys, Brit. Concli. vol. ii. p. 21, 1863, and vol. v. p. 164, pi. xix. fig. 5, 1869.

Gwynia capsula, M. Sars, Om de i Norge forckommende fossile Dyrlevninger fra Quartaerperioden,
Christiania, p. 96, pi. iv. figs. 121, 122, 1865 ; Davidson, Br. Foss. Bracb. vol. iv. p. 5, pi. i. figs. 3-4,
1874; H. Friele, Arcbiv for Mathematik og Naturvidenskab, Bd. ii. p. 385, pi. iii. figs. 7 « & 6, 1877.

Argtop)e capsula, Tei-quem, ' Essai sur le classeraent dcs animaux qui vivent sur la plage dans les
environs de Dunkerque,' 1879 ; Gwyn Jeffreys, Ann. & Mag. Nat. Hist. 5tb ser. vol. vi. p. 406, 1880,
audProc. Zool. Soc. 1881, p. 949.

Shell thin, minute, pouch-shaped, or slightly elongated oval, nearly equivalved, longer
than wide, hroadest anteriorly, rounded in front ; hinge-line nearly straight or very
ohtusely angular, margins rounded at the sides. Dorsal valve convex, most so at the umho,
slightly depressed anteriorly. Ventral valve uniformly convex ; heak slightly prominent
and incurved ; foramen incomplete, margined anteriorly hy the umho, and hy small
rudimentary deltidial plates. Interior without loop or septa (?). Surface of valves
smooth ; shell-perforations rather large and f:\r apart. Lines of growth slightly marked.
Colour nearly white, glossy. Length two thirds of a line hy half a line in hreath.

Salt. Off Plymouth, in 18-25 fathoms (Norman, from Wehster). On stones near
Guernsey, 8 to 20 fathoms (Lukis and Duprey). Duhlin Bay and off Portsmouth (Waller).
Belfast Bay, Larne, County Antrim (Hyndman and Gwyn Jeffreys). It occurs with
C. cistellula, nestling in hollows of old shells, Fectunculus glycymeris, and other hivalves.
Off Etretat, in Normandy, on stones which had heen taken up in trawl-nets at a distance of
ahout four leagues from land (Gwyn Jeffreys). Off Dunkerque (Terquem). M. Colheau
ohtained the shell from Sluys-Kill, Zeeland, near the Belgian frontier. Off Jersey, low
water (Duprey), where it adheres hy its short stout peduncle in an upright position to
the undersides of large stones which are sunk and partly buried in the sandy mud
(Gwyn Jeffreys).

It also occurs fossil iu the Post-tertiary clays at Kirkoeu, near Christiania (Sars).

Ohs. I have specimens of this minute shell, from the size of a microscopic dot up to
little more than half a line in length. I cannot, however, arrive at any other conclusion
than that it is the fry or young stage of some species not at present determined. The shell
has already heen referred to Terebratula, Arcj'wpe, and Gioynia. Dr. Gwyn Jeffreys and
Ilerr Herman Friele believe it to he referable to Argiope or Cistella, and in vol. ii. p. 22 of
his 'British Conchology,' Gwyn Jeffreys writes, " It may he the young of Argiope NeapoU-

DE. T. DAVIDSOX OX EECEXT BEACIIIOPODA. 151

tdtin (probably T. cordala of Risso) ; and I feel pretty confident that the last-named
species will be found on our own as well as the Mediterranean coasts." In 1859, Dr. S. P.
Woodward and myself spent a whole day at the British Museum in endeavouriii"-, with
tlie aid of a good microscope, to find some kind of calcareous support, or septum, l)ut could
tind none; nor has any other naturalist who has studied the shell been more successful.
In 1859, Prof. W. King proposed tlie generic name of Gwijnia for this form, statin"- at the
same time that "the principal generic character of Gwyuia is in the labial appenda"'es
being attached directly to the shell (first observed by Mr. Jeffreys), and not to a loop, as
in other genera of the family. The prominency of the umbonc of the small or receivin"-
valve, the form, position, and (considering the size of the species) the unusual develop,
ment of its teeth, also the large size of the perforations of its shell-tissue, form other
good distinguishing characters." We must, however, for the present, assume that no
calcareous support in reality exists.

In a note published in the 'Ann. and Mag. Nat. Hist.' for Xov. 1880 (p. 400), Dr. Gwvn
Jeffreys again returns to the subject, in referring to what he terms Arcjiope capsula, and
says :— "The specimens kindly sent me by Mr.Duprey are larger than any I had previously
seen ; and I was enabled to examine the inside of the shell by soaking them for some
days in dilute potash water, together with Argiojye clstellula of the same size. A. can-
sula has a thick hinge ; and the smaller (though scarcely smaller) valve has a sharp-edo-ed
and wavy crest or ridge lying a little within the margin, which is heart-shaped and con-
tinuous in front. The shell is strong for its size, and is nearly spherical and cquivalve, the
beaks of both valves being excavated to contain the b^ ssus. There is no trace of a septum
in either valve. The caecal tubercles are numerous, twice as many as in ^. cislellula of
the same size. The latter species is transversely oblong ; there is a distinct and promi-
nent septum in each valve ; and the laminar ridge in the smaller valve is much sli<'hter
and is interrupted by the septum to which it is attached. Both species occur too-ether
on the English and Irish coasts, and at Etretat in Normandy."

In his paper on the development of the skeleton in the genus Woldlieimia, Herman
Eriele says (p. 385), " Dr. Jeffreys has had the great kindness to send me his type-speci-
mens of Gwjjnia {Arfi'iope) copsiila, Jcffr., for comparison. My first glance at them sufficed
to convince me that there can be no question as to their [not *] being the fry of Wcddheimia
cranium, for not only are both valves of very nearly the same size, but the form, the
foramen, and the structi.u*e of the shell are essentially different."

Mr. Lovell Beeve writes, in his ' Geographical Distribution of the Terebratula; ' f , " Is
this very minute form, it has been asked, an adult shell, or the fry oi Arrjiope cistcllulum
or of some other Tevcbmtvla ? An Argiope it certainly is not ; and I am unable, after a
most tedious examination of specimens, to add anything