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 0 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 to what is knoAvn on the subject."
The question being still involved in considerable uncertainty, it will be better, I
think, at any rate provisionally, to leave it under Gwrjnia, from which it may be
hereafter removed, if anything definite should be ascertained concerning it.

* [Hcrr Friclo writes Ai)ril lOtli, ISSO, tliat " by a printer's error the -svord ' not " was omitted here : " and Ihis
is evident from the rest of the passage quoted. — A. C]
t Ann. & ilajr. Nat. Hist. 3rd scr. vol vii. p. 1,^3.

152 DE. T. DAA'IDSON ON EECENT BEACHIOPODA.

Mr. W. H. Dall, iu liis Index to the names wliich have been applied to the subdivi-
sions of the class Brachiopoda (Smithsonian Miscell. Coll. vol. xiii., Bull. U. S. Nat.
Mus. vol. i. no. 8, p. 30, Washington, 1877), states, as many zoologists have done, that
the so-termed Gioijnia capsula is an immature form, and perhaps that of JFaldheimia
cranium.

Genus PLATYDIA, Costa.

The subfamily into which the genus J^latydia should be placed has not yet been
satisfactorily determined. It is thus characterized by Dall : — " Shell with the loop
attached, not reflected ; animal with sigmoid brachia meeting behind the mouth, without
any spiral median lobe or lateral loops. Cardinal process absent."

The genus FlatyiUa was proposed by Costa in January 1852, and by myself, entirely
independently, in May of the same year, under the name of Jjforrisia, which must now be
placed among the synonyms.

The animal of FlatycUa has not yet been anatomically examined.

89. Platydia anomioides (Scacchi), Philippi, sp. (Plate XXI. tigs. 15-19.)

Terebratuhi Seminuluni; Pliilippi, Eumn. Moll. Slcilite, vol. i. p. 97, pi. vi. fig. Ija-ff, 1836.

Orthis anoiiiioides (Scacchi, AIS.), Pliilippi, Fauua ]\Ioll. llegui iitriusquc SiciliiE, vol. ii. p. 69,
pi. xviii. fig. 9, 1844.

Terebratuhi appressa, E. Forbes, Report of the Mollusca of the ^Egean Sea, Report Brit. Assoc, for
1843, pp. 141, 167, 193, 1844.

Platidia anomioides, Costa, Fauna del regno di Napoli, p. 48, pi. iii. fig. 4, and pi. iii. bis. fig. 6, 1852.

Morrisia seniinulum, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 371, 1852.

Morrisia anomioides , Davidson, Proc. Zool. Soc. 1852, pi. xiv. fig. 29 ; Intr. to vol. i. Brit. Foss. Brach.
p. 71, pi. vi. figs. 30, 31, 1853; Woodward & Gray, Catalogue of Brachiopoda in the Brit. IMus. p. 108,
figs. 17, 18, 1853; S. P. Woodward, A Manual of the Mollusca, p. 218, 1856; H. & A. Adams, The
Genera of Recent Mollusca, vol. ii. p. 579, pi. cxxxi. figs. 5 a, b, 1858 ; E. Suess, Ueljcr die Wohnsitze
der Brachiopoden, Sitzungsb. k. Akad. Wissensch. Wien, p. 212, 1859.

Terebratula (^Morrisia) anomioides, L. Reeve, Conch. Icon. pi. x. fig. 40, 1861, Ann. & Mag. Nat. Hist.
3rd ser. vol. vii. p. 184, 1861 ; Chemnitz, Man. de Conch, p. 208, fig. 1064, 1862.

Morrisia anomioides, E. Dcslongchamps, Recherches sur I'Orgauisation du Alauteau chez les Brachio-
podes articules, Caen, p, 28, pi. iii. figs. 6, 7, 1864; Seguenza, Cat. Mai., Mem. Soc. Ital. Sci. Nat.
p. 66, pi. viii. fig. 6, 1865 ; H. C. Weinkauff, Die Conch, des Mittelmeeres, vol. i. p. 288, 1867.

Platidia [Morrisia) anomioides, Davidson, On Italian Tert. Brach., Geol. Mag. vol. vii. p. 405, pi. xxi.
figs. 15, 15 «, 1870; Dall, Amer. Journ. of Conch, vol. vi. p. 143, 1870, and Proc. Acad. Nat. Sci.
Philadelphia, 1873, p. 192; P. Fischer, Brachiopodes des cotes oceaniques de France, Journ. de Couch,
vol. XX. p. 162, 1872; Monterosato, Poche note sulla Conch. Meditcrranea, 1875.

Platidia seminulum, Monterosato, Journ. de Conch, vol. xxvii. p. 307, pi. 13. fig. 3, 1879.

Platidia anomioides, Davidson, Report on the Brachiopoda, Voyage of H.M.S. ' Challengci-,' Zool-
vol. i. p. 55, pi. iv. figs. 10, 11, 1880; Zittel, Handbuch der Pal. Bd. ii. p. 708, 1880; E. Dcslongchamps,
Etudes critiques sur les Brachiopodes, p. 160, pi. xiii. fig. 19, 1884.

Shell small, transversely oval, or nearly circular, semitransparent, yellowish Avhite,
con.spicuously perforated by minute canals ; foramen large, encroaching nearly equally

DR. T. DAVIDSON ON EECENT ERAC'IIIOPOD.A. 153

on both valves. Dor.sal valve almost flat, and nicsially doprossod ; umbo nolchod by a
semicivcnlav foramen. Ventral valve convex, of moderate deptii, hinge-line straight,
area small. Beak very slightly incurved, foramen situated under its angular extremity,
margined liy narrow deltidial plates. Surface smooth, marked willi concentric lines of
growtli. In the interior of the dorsal valve the loop is not reflected. The converging
principal lamelhTB are found attached first to the hinge-plate, and then to a small pillar-
shaped median vertical septum. Peduncle very short ; animal possessed of sigmoid
vertical labial appendages. Length 2 lines, breadth 2 lines.

TIah. Dredged in the J<lgean Sea by Prof. E. Porbcs, under the names of Terehratula
semlmilum, Philippi, and T. appressa, Forbes, at depths varying from 45 to 105 fathoms; in
the Bay of Naples (Costa) ; off the Portuguese coast, near the mouth of theTagus, attached
to corals (W. S. Kent); Bay of Biscay and Sahara (' Travailleur ' Expedition), in 178 to 347
fathoms ; North of Stornoway (' Knight Errant ' cruise) ; off Cuba and AVest Indies
('Blake' Expedition), 88 to 615 fathoms; off Marion Island in 500 fathoms, and off
Prince Edward's Island close to Marion Island (' Challenger ' Expedition). Mr. W. H.
Dall records it from San Diego, California, and from Lodos, Santos Bay, south of the
United- States boundary in Lower California (Mexico).

It occurs in the fossil state in the Upper Pliocene rocks of Sicily.

Obs. As the specific name anomioides is now in general use, I do not feel inclined to
disturb it, although those of seiniimlnm and of appressa, Eorbes, seem to have priority.
Forbes neither described nor figured his species, and therefore it cannot be said to have
been published. The name anomioides is attributed to Scacchi, but he has neither
named, described, nor published it. It was a MS. name known to Philippi and to Costa,
and they both described and figured a shell in 1844 and 1852 under the name of Orthis
anomioides. As the Terehratula semiimlitm, Philippi, is evidently identical with the
so-termed Orthis anomioides, and was described and figured in 183G, the specific name
seminulum should in reality obtain priority over that given to the shell in MS. by Scacchi.
In May 1852 I proposed for T. seminulum anA. similar shells the generic name of Morrisia,
not being aware at the time that Costa on the 27th of January of the same year had
proposed that of Vlalijdia for the same shell.

The animal of this interesting and well-marked genus and species has not yet been
anatomically examined. The arrangements of its labial appendages are very remarkable.
They were briefly described and figured by Costa and by myself in 1852, but more particu-
larly by E. Deslongchamps in 1804, in his valuable memoir, ' Recherches sur I'Organi-
sation du Manteau chez Ics Brachiopodes articules.' His observations were, however,
like my own, nnfortunately founded on dried specimens. He states that the brachial
appendages are much more simple than in other genera of the Brachiopoda, and that
the two principal branches which lie close to each other at their origin and deviate by
a curve towards the centre of the shell, and, having made almost a complete circle, return
close to their origin, without forming a spiral. His most imponant observations, how-
ever, relate to the mantle, which he states to be so thickly coated with spicula that it is
impossible to separate it from the brachial appendages without injuring them; that

154 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

they are small, but exceedingly numerous, and yet so blended together that it becomes
at last very difficult to define their shape ; and that they appear to be a white spongeous
mass formed of an innumerable number of short lamellae, crossing each other in every
direction. In his paper " Brachiopodes des cotes oceaniques de France " (' Journal de
Couchyliologie,' vol. xx. p. 160, pi. vi. figs. 3-9, 1872), M. P. Fischer describes at
great length PlatycUa anomioides, and the characters that distinguish it from Flatijdia
Davidson i. He gives an enlarged sketch of the brachial appendages, Avhich he likcAvise
states to be extremely simple. " De chaque cote de la bouche part une portion hori-
zontale qui se coude eusuite et forme une premiere anse ou boucle buccale. EUe est
continuee de chaque c6t6 par la portion currente dirigee du crochet de la valve vers le
bord frontal et en rapport avec la valve inferieure ou dorsale ; cette portion currente se
coude, decrit un ccrcle complet (anse ou boucle laterale) et revient au-dessus de la portion
currente en etant en rapport avec la valve dorsale ; elle se termine enfin par une
sinuosite dirigee vers la bouche. C'est la le rudiment de la portion spirale, qui est
assez developpee chez les Megerlia et beaucoup plus marquee chez les Terebratula.
L'appareil brachial ressemble done a celui du Platidia anomioides ; mais la boucle
est moius large, par rappoi't aux boucles laterales. Les cirrhes des bras sont assez longs
et disposes par paires, ou plutot chaque cirrhe semble se diAdser en deux filaments egaux.
Ce caractere a etc represente, chez le Platidia anomioides par M. Davidson."

Owing to the extreme shortness of the peduncle, the ventral valve is kept so close to
the object to which it is attached that the asperities or irregularities of the rock or shell
are often reproduced upon it. This peculiarity is especially observable on the smaller
valve of PlMi/dia anomioides.

90. PLA.TYDIA Davidsoni, E. Deslougchamps, sp. (Plate XXI. figs. 23-27.)

Morrisia Davidsoni, E. Deslougcliamps, Ann. & INIag. Nat. Hist. 2ud ser. vol. xvi. p. 443, pi. x. figs.
20 a-d, 1855 ; Seguenza, Mem. Sue. Ital. Sci. Nat. vol. i. p. 07, pi. viii. fig. 5, 18G5 ; E. Suess, Ueber die
Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. Wisseusch. Wieu, p. 212, 1859.

Terebratula {Morrisia) Davidsoni, L. Reeve, Coucli. Icon. pi. x. fig. 42, 1861, and Ann. & Mag. Nat.
Hist. 3rd ser. vol. vii. p. 181, 18G1.

Platidia Davidsoni, Dall, Amer. Journ. of Coneli. vol. vi. p. 143, 1870, and Proc. Acad. Nat. Sci. Phila-
delphia, 1873, p. 192; P. Fischer, Brach. des cotes oceaniques de France, Journ. de Conch, vol. xx.
p. 163, pi. viii. figs. 8-9, 1872, and Etudes Couch. Slarines du Dep. de la Giroude, Soc. Linn.
Bordeaux, t. xxix. p. 170, 1874; Monterosato, Poche note suUa Conch. Mediterr. 1875, and Note sur les
esp^ces du genre Platidia, Journ. de Conch, vol. xvii. p. 300, 1879.

Shell small, semicircular or transversely oval, often irregular in shape and unequi-
lateral, wider than long, subpellucid, yellowish white. Dorsal valve flat and irregular,
assuming the shape of the objects upon which it lies in close contiguity ; concentrically
striated, and perforated by rather large canals ; deeply notched at the umbo by a large,
wide, semicircular aperture, which constitutes almost the entire foramen. Ilinge-line
straight, a little shorter than the breadth of the shell. Ventral valve uniformly convex,
cardinal angles rounded ; beak short, slightly incurved, beak-ridges sharply defined, with
a very narrow area or flattened space between them and the hinge-line, in the middle a

I)E. T. DAA'IDSON 0,\ EECE^"T BEACHIOPODA. 155

very Avidc, rudimentary, obtusely anyular lissurc represents the foramen, on each side of
which are two very narrow rudimentary deltidial plates. Shell irregularly concentrically
striated, Avith numerous small asperities rising- Irom its surface. Shell perforated hy
canals visible under feeble magnifying-power. Length 3 lines, breadth 5 lines. Valves
articulating by means of teeth and sockets. Interior of the dorsal valve not com-
pletely known. Short cylindrical processes project into the interior of the shell from a
little under each angle of the wide semicircular foramen, and from about the middle
of the bottom of the valve arises a thickened pillar-shaped process or septum, curved
towards the hinge, and forked at its extremity.

Rah. Found attached to large specimens of CaryophylUa ramosa from the coral-fisheries
near Tunis, and at other places in the Mediterranean (E. Deslongchamps and Fischer) ;
it was also dredged hy the Marquis de Folin at Cap Breton (Landes) in 25-70 fathoms.

OIjs. In exterior aspect this spegies quite resembles an Anomia. It is the largest form
of the genus 'Platijdia with which we are at present acquainted. It was well described
in 1855 by M. E. Deslongchamps, and subsequently with greater detail by Dr. Paul Fischer
in two memoirs already referred to. In his paper, M, E. Deslongchamps says : — The
dorsal valve is at times very irregular, owing chiefly to the shortness of the peduncle.
From a superficial examination of the animal in a dried condition my father and
myself were enabled to convince oui-selves that the labial appendages seem connected
with the apophysary system hy a kind of very delicate network, reminding one of the
descending apparatus in TheckUum, which in some species is formed in its upper portion
by a calcareous network freely suspended above the visceral cavity.

In his memoir on JPlutijdia, published in the ' Journal de Conchyliologie,' vol. xii.
p. 160, 1872, Dr. Paul Fischer describes and figures some good examples of Pluti/dla
Davidsoni dredged hy the Marquis de Folin from tlie Fosse du Cap Breton, which I have
also been able to examine through the liberality of the Marquis. In another paper,
issued in the Actes Soc. Linn. Bordeaux, t. xxix. 1874, Dr. P. Fischer says (p. 171) : —
The brachial apparatus is supported by a little calcareous forked pillar rising from
the middle of the dorsal valve. . . . The forked pillar is proportionally much longer
than in individuals of similar dimensions of IlegevUa tnmcatu. Mecjerlia tnmcata can
be so modified that the valves become moulded on their substratum ; this is occasioned
by the shortness of the peduncle, and therefore the peduncular aperture is found almost
completely transferred to the dorsal valve — a malformation raised to the rank of a
species by the name of J/<?i^er^i« mo«s^r«o«a, Scacchi ; but even in this case we recognize
the characters of the species at all ages, and at no stage do Ave find the rudimentary
apophysis of Flatydia Bacldsoni. Dr. Fischer proceeds [1. c.) : — The general arrangement
of the brachial appendage, in P. Duindsoni, is extremely simple. On each side of the
mouth proceeds a horizontal portion, which afterwards bends and forms an incurvature
(boucle). It is continued on each side by the running portion directed from tlu^
beak of the valve towards the frontal margin, and connected with the dorsal valve ;
this part (portion currente) bends, describes a complete circle, and returns above the
running portion, being in relation to the dorsal valve ; it ends at last l)y a sinuosity

SECOND SERIES. — ZOOLOGY, VOL. IV. 21

15G DR. T. DAVIDSON ON RECENT BRACHIOPODA.

directed towards the mouth. This is the rudiment of the spiral portion which is
moderately developed in Megerlia, and much more marked in Terehratula. The
brachial appendages (in Platydia Davidsoni) resemble therefore those of Platijdia
anomioides. The cii'ri of the arms are rather long, .... disposed in pairs, or rather
each cirrus seems to he divided into equal filaments. This character has been repre-
sented by Mr. Davidson in Platydia anomioides.

The characters of Tlatijdia Daridsoni are very remarkable. In Megerlia the
peduncvilar opening encroaches a little on the dorsal valve, more especially in the
variety monstruosa. In JPlatijdia anomioides the foramen is almost entirely on the
dorsal valve, and finally in JPlatydia Davidsoni the ventral valve is devoid of fissure,
and its beak forms a median projection. This remark, however, is scarcely correct,
for there exists under the beak an indication of a shallow fissure. There are,
continues Dr. Fischer, important exceptions among the articulated Brachiopoda, since
the perforated valve is not foraminated in 'Platydia Davidsoni. All these changes are
produced by the shortening of the peduncle, which obliges the Brachiopod to live in close
contiguity with a rock, and to rejiroduce the irregularity of the object upon which it is fixed.
Since the above was written, M. E. Deslongchamps has described the different stages
in the development of the loop in 3Iegerlia truncata, and points out that at one stage
the dissimilarity between it and Dlatydia, although apparent, is not so very great.

In Platydia anomioides the principal stems of tlie loop, after having become attached
to the base of the hinge-plate, become fixed to the central pillar-shaped process arising
from the bottom of the dorsal valve ; but in Platydia Davidsoni these principal stems,
in the specimens examined by M. E. Deslongchamps, Dr. Eischer, and myself, were
either broken or absent ; so that to ascertain tlicir real condition more specimens will
have to be examined hereafter.

Family THECIDIID^.

Genus THECIDIUM, Defrance, 1828.

We are acquainted with but two recent species of this genus, viz. Thecidium mediter-
raneum, Risso, 182(5, and Thecidium Barretti, Woodward, 1861.. The generic characters
have been fully described under Thecidium mediterraneum. The animal and embryology
of the bst-named species have been admirably described and illustrated by Lacaze-
Duthiers and otliers.

91. Theciditjm mediterraneum, Eisso. (Plate XXIII. figs. 12-22.)

Theddea mediterranea, Risso, Hist. Nat. des Priiicipales Prod, de TEurope meridionale, t. iv. p. 394,
pi. xii. fi-. 183, 1826; Blaiuville, Diet. Sc. Nat. t. liii. p. 434., 1828; Deshayes, Encycl. Meth., Vers,
t. iii. p. 135, 1830 ; Pliilippi, Emim. Moll. Sicilife, vol. i. p. 99, pi. vi. fig. 17, 1836, and vol. ii. p. 70, 1844.

Tliecidea? spondi/lea, ScaeeLi, Cat. Conch. Regni Neapolitani, p. 8, pi. ?, fi^s. 8-10, 1836.

Tliecidea mediterranea, Dcsh. cd. Lamarek's An. sans Vert. vol. vii. p. 346, 1836; Anton, Verzeichniss
Conch, p. 21, 1839 ; Kiister, nov. ed. Chemnitz's Couch.-Cah. pi. 2 c. figs. 22-25, 1843 ; G. B. Sowerby,
Thes. Conch, p. 371, pi. ixxiii. figs. 30-32, 1846.

Tliecidea testudinaria, Michelotti, Dese. des Foss. Jliocenes de PItalie Sept. p. 79, pi. ii. fig. 26, 1847.

DE. T. DAVIDSOIS' ON EECENT BRACHIOPODA. 157

Tlwcidea niediterraiica, O. (r. Costa, Fauna del Regno di Xajjoli, p. 19, pi. ix. figs. 1-3, 18.J2 ; David-
son, Ann. & Mag. Nat. Hist. 2nd scr. vol. ix. p. 374, 18r)2 ; A. Adams, The Genera of Recent MoUusca,
p. 581, pi. cxxxii. fig. 1, 18.")8.

Tlu'cidiuiii ijwditcrraneum, Davidson, Brit. Foss. Bracli. vol. i. Introduction, p. 77, fig. 2'.), 18.~>3 ;
Woodward and Gray, Catalogue of the Brachiopoda in the British Jluseum, p. 118, 1853; S. P.Wood-
ward, A Manual of the MoUusca, p. .'221, fig. 128, 185G; E. Sucss, Ueber die Wohnsitze dcr Brachio-
poden, Sitzungsb. k. Akad. dor Wissenseh. "Wien, Bd. xxxvii. p. 21G, 1859; Laeaze-Duthiers, His-
toirc de la Tlu'cidic mediterrancuin, Ann. des Sciences Nat. 4' ser. Zool. vol. xv. p. 259, pis. 1-5, 18G1.

Tenbrutula (Thec'nft'n) nicillh-rnitica, L. Reeve, Couch. Icon. pi. xi. fig. 48, 1861, and Ann. & Mag.
Nat. Hist. 3rd ser. vol. vii. p. 18G, 1861.

Tlwcidea mediterranea, Verani, Zool. dcs Alpes Maritimes, Nice, 1862 ; Chinu, Manuel de Conch,
vol. ii. p. 212, figs. 1087-1089, 1862.

Thi'c'idiiini iiicdikiraneinii, Davidson, Geol. Mag. vol. i. j). 11, pi. i. figs. 1-3, j)!. ii. figs. 5-10, 1864 j
E. Deslongehaiups, Rechcrchcssur I'orgauisationdu Manteau chcz Ics Brachioj)odcs Articuk's, p. 31, pi. iii.
figs. 10-12, Caen, 1861; 11. C. WeinkaufF, Die Conch, des Mittelmeercs, p. 291, 1867; Dall, Amer.
Journ. of Conch, vol. vi. p. 151, 1870, and Proc. Acad. Nat. Sci. Philadelphia, p. 195, 1873; Gwyn
.Icffrcys, Proc. Zool. Soc. 1878, p. 412, & 1881, p. 919.

Shell small, somewhat pyriformly ovate, variable in sliape, tliiciv, attached to laavinc
ohjects by a portion of the beak of the ventral valve. Colour dead white. Dorsal valve
thin, semicircular, sliglitly truncated in front ; hinge-line straight, shorter than the
breadth of the shell, gently convex, most so at the umbo, flattened near the margin.
Ventral valve more or less regularly pyriform, very convex, thickened, longitudinally
depressed along the middle ; beak callous, much produced, irregular on account of the
position and extent of its attached surf;xce ; area large, triangular. Hat, Avith a slightly
raised, flattened, triangular pseudo-deltidium ; no foramen ; shell-structure punctate.
Surface of valves smooth, marked with concentric lines of growth. In the interior of the
dorsal valve the hinge-plate is large, squarely oblong, prominent, and concave. There
exists outside each of the socket- depressions an oval muscular scar, attributed by Lacaze-
Duthiers to his " lateral adductor muscles " (adjustors of Hancock). A broad, thickened,
sloping, granulated margin encircles the valve, and forms a bridge (Plate XXIII. fig. 10,
h) over the small deep visceral cavity, and close to the basis of the hinge-plate, or cardinal
process. The granulations are larger and most prominent as they recede from the outer
margin. This inner denticulated or granvilated margin follows in a parallel manner the
margin of the shell from the In-idge-shaped process {h) until it nearly reaches the middle
of the frontal [c), where it suddenly stops and becomes inflected upwards. At the point
(c) the margin is again directed upwards, producing a second parallel curve, when at {e)
by another downward curve it forms a tliird short parallel concave curve, until it reaches
the point {f) near the centre of the valve, where it combines with the similar inflections
of the other lialf of tlie shell, so as to produce on tlie median line an upwardly produced
tongue-shaped process (/y), the angular extremity of which is directed towards the middle
of the bridge-shaped process {h). These four symmetrically bent ridges or lobes con-
stitute M. E. Dcslongchamps's " ascending apparatus," the central portions (/ and g)
are more elevated than the other parts, and overlie a portion of the visceral cavity.
The parallel grooves or spaces left between the ridges above described are partially

21*

158 DR. T. DAVIDSON OX EECEXT BRACHIOPODA.

occupied by a lamella in the shape of a double crescent {i and 1-), of which the larger
branches (i) partly occupy the large cavities left between the first and second ridges,
these being on their inner sides intimately united with the sides of the grooves ; while
the shorter branches {^■) are freely suspended over the visceral cavity, and occupy the
spaces left between the third and fourth ridges of the ascending apparatus. To these
crescent-shaped lamellae M. Deslougchamps has given the name of " descending appa-
ratus." The interior of the ventral valve is concave and deep, with a small longitudinal,
rounded, mesial elevation ; the hinge-line is straight, and on each side at the base of the
deltidium strong hinge-teeth for the articulation of the valves are situated. The beak is
hollow ; l)ut there exists on the median line, and far back in the cavity, a small elevated
septum, to each side of which is attached a very small thin concave plate (Plate XXIII.
fig. 15, b), to Avhich, according to M. Lacaze-Duthiers, the adductor muscle, or " occlusor "
of Hancock, was attached. On the bottom of the valve, a little low^er down, and on each
side of the mesial elevation, and partly under the cavity of the beak, a large pyriform scar
is observable, to which the " divaricator muscles " of Hancock were attached (c) ; and,
lastly, external to these, on the bottom of the valve, and near the angles of the hinge-line,
there exists a small oval scar (a), which is believed to have been produced by the "ven-
tral adjuster " of Hancock. The remaining surface of the shell is closely covered with
numerous granulations or asperities. Length 3 lines, breadth 2|, depth 2 lines.

Hab. Mediterranean, especially on the African coast, in from 30 to 300 fathoms.
Bay of Xaples ; off the coast of Sicily. Algerian coast, from Bone to near Cape Eosa.
Off Jamaica, 60 to 150 fathoms (L. Barrett). In the Gulf of Mexico (' Blake ' Expedi-
tion), 163 fathoms. It is also stated by Sir H. Barkly to occur off Mauritius ; but this
statement must be taken with reserve.

TheckUmn mediterraneum occurs fossil in the Miocene and Pliocene rocks of Italy.
Ohs. The animal and its embryology have been admirably described and illustrated by
M. Lacaze-Duthiers. We extract the following notes from his important paper : —

Belative to the muscles, M. Lacaze-Dvithiers states that there are three pairs, six in
all, possessing distinct directions and functions. Of these muscles, two (woodcuts, figs. 16,
17, 18, a) are lateral, short, wdde, easily observal^le, and serve without doubt for the
occlusion of the shell. These are M. Lacaze-Duthiers's " muscles adducteurs lateraux ou
externes," which, Mr. Hancock informs me, Avould represent his "adjustors," but that the
function of this pair of muscles does not appear to be exactly similar to the " adjustors "
of Waklheimia, in which they move the shell upon the pedicle ; in ThecicUum they
assist in closing the valves suddenly, and in preventing any irregular or lateral movements
W'hich, from the central position of the occlusors, might be liable to take place. In fact,
he believes that the function of the "adjustors " in ThecicUum is modified much as it is
in the same muscles of Linr/ida; and he is therefore inclined to conjecture that the two
valves of the former are not so firmly hinged as they are in the other articulated forms.
The second pair of muscles {h of woodcuts) are those nearest to the median line ; these
are termed " muscles adducteurs internes " h\ M. Lacaze-Duthiers, and correspond, or are
equivalent to, Mr. Hancock's anterior or posterior occlusors. In the central valve these

DE. T. DAVIDSOX OX EECEXT BRACIIIOPODA.

159

muscles would bo fixed to the bottom of tlic valve, nearly iiiider the extremity of the touguc-
shaped "ascending shelly process" already descril)ed (Plate XXIII. fig. IG, cj), and be again
attached to the two thin shelly processes (Plate XXIII. fig. 15, b) which we have described

Fkr. 10.

Fisr. 17.

V\<x. IS.

After Lacazc-Diithiors, ' Annalcs des Sciences Xaturollcs,' Zool. t. xv. pi. i. figs. 7, 8, 9.

Fig. K). Longitudinal section of TheckUum, to give an idea of the manner in which the median muscles act : n
curved lamelhr, which are supported by and attached to a small septum under the beak in the ventral
valve : h, median adductor muscle of Lacaze-Duthiers ( = occlusor of Hancock); c, adductor muscle of Lacaze-
Duthiers, which is attached by one extremity to tlu; bottom of the ventral valve, and by the other end to
the extremity of the quadrilateral cardinal process of the dorsal valve. 31. Laea/.e-Duthiers states that
the mechanism of the opening and occlusion of the shell can be thus formulated : when the animal
wishes to open its shell, the power, P, is represented by the muscle (c), its point of application being at
the extremity of the cardinal process of the ventral valve ; the resistance, E, is the weight of the valve
which has to be raised ; the point of support is found at A ; we have, thus represented, a lever of the
first kind. When the shell has to be closed, the same analysis would be applied to the lateral muscles,
reversing, however, the power and the resistance, the point of support being always at the articulation A.
Fig. 17. Animal, with the lobes of the mantle spread out, viewed from the side of the shell so as to exhibit M.
Lacaze-Duthiers's {a) muscles adducteiirs lateraux (Hancock's adjusters) ; J, Lacaze-Duthicrs's " muscles
abductours medians " Cllancock's occlusors), of which one extremity passes between the " muscles abduc-
teurs " (<■), and the other is directed outwardly to make room for the intestine ((7) which is the continua-
tion of the lobes of the liver (e) ; c is Hancock's divaricator.

Fig. IS. Animal, separated from the shell, and seen on the face which corresponds to the coTicavo valve : a. lateral
adductor muscle of Lacaze-Duthiers ; h, median adductor muscle, of which the extremity only can be
seen, which attaches itself to the bottom of the lamcllai under the beak of the ventral valve : c, adductor
muscle slightly curved, of which the two extremities can be seen.

as existing in the cavity of the beak. The function of these muscles (as stated by j\[.
Lacaze-Duthiers) would also be to effect a closing of the valves, but less efficaciously than
the preceding pair. The third pair, designated " muscles abducteurs " l)y the same author
(woodcuts, figs. IG, 17, 18, c), arc Mr. Hancock's " divaricators," and tlieir function Avoukl
be to open the valves. They form large impressions on tlie bottom of the ventral valve, on

IGO DR. T. DAVIDSON ON KECEXT BliACHIOPODA.

each side of the central septum (Plate XXIII. fig. 15, c) and Liave their outer end attached
to the extremity of the cardinal process of the dorsal valve. M. Lacaze-Duthiers has had
the opportunity of studying a vast numher of individuals of this species of Thecidiiiia in
the living state ; and he mentions that, contrary to what we find to be the case in Tei^e-
hraiula, the animal opens its shell very widely — the dorsal valve rising on its hinge at
right angles to the ventral valve, like the lid of a snuff-box (woodcut, fig. 16, c). The
animal is also sensible to light and darkness ; and it draws down its smaller valve with
the rapidity of lightning on the approach of danger.

M. Lacaze-Duthiers further observes that the mantle is exceedingly thin, and is not
famished round the margin with any of the long setse which exist in Terebratula and
L'mgida, and that the genital lobe (the one which corresponds to the concave or ventral
valve) differs much from the other, and is characterized in its thickest lobe, or central
portion (that is to say, towards the deep and concave j)ortion of the valve), by very thick
calcareous plates, the analogues of the plates and spicula occurring in the mantle of Tere-
hratula. Tiiese plates in Thecidium participate in the character of the shell itself, being
smooth on the under surface, and covered on the npperside with asperities similar to those
which cover the entire surface of the bottom of the valve. The plates are very thick, and
form a ceiling or vault over the cavity which contains the organs of reproduccion. Tliey
have been carefully described and figured by M. J. Bosquet, M. E. Deslongchamps, and
myself, as seen in several fossil species, and in particular in Thecidium cermlculare, from
the Upper Cretaceous beds of the Duchy of Limbourg.

M. E. Deslongchamps says, at pp. 30, 31 of his memoir on the Organization of the
Mantle in the Articulate Brachiopoda: — In short, the Thecidiidte possess an altogether
peculiar organization of the mantle. Calcareous spicules crowding the external laminae
are no longer present, but true calcareous plates which obliterate almost the whole
interior, and form, as it were, a second shell, line the interior of the valves, and
give them a most strange and elegant appearance. We will not now repeat the details
of the conformation of these curious lamina? constituting the pallial apparatus, which
can, it would seem, be better studied in the fossil than in the recent species, and of which
a large number of authors have given excellent descriptions. We will only mention that
this apparatus undergoes very great modifications in different species, being sometimes

excessively complicated, as in T. recurvlrostrls, whilst in others this apparatus is

reduced to an indistinctly marked single lamella, as in T. Perrleri

Another very striking peculiarity is revealed to us in the organization of the tissues of
Tliecidea medUerranea. We have seen hitherto, except hiArglope, which formed the ex-
ception, that it was in the arms and their cirri that the calcareous spicula wevQ especially
developed, and that it was in these organs that they began to appear in the earliest stages of
the shells, extending progressively on the two laminae of the mantle. We note that precisely
the contrary occurs among the Tliecididae. The majitle is no longer, so to say, merely a
calcareous mass, and the arms and their cirri do not show the smallest trace of spicula or

even of calcareous granulations It is apparent that the arms constitute a simple

diaphanous membrane, which is rather difficult to distinguish even by a feeble magnifying-

DR. T. DAYIDSOX ON EECEXT BRACIIIOPODA, Kil

power, as tlio walls avo so dcliratc; whilst the calcified portion of the mantle is very
thick, of a dull white colour, apparently of a spongy nature, and under the same
enlargement seems to us much nun-e compact than even the walls of tlio shell. In oi-dcr
to realize the diverse condition of the mantle thus calciGcd, we must call to our aid high
magnit'ying-])owcr.

]\I. Lacaze-Uuthiors states, in the work previously quoted, that the so-termed " oral
arms " or lal)ial appendages of Thocidium resemhle those of other Brachiopoda, except that
they are not free, hut adhere throughout their extent ; that the swollen basis certainly
presents a canal similar to that which exists in the other animals of the same group, and
that this longitudinal canal is present throughout their length, heing almost confounded
with the mantle, or with the margin of the body, and is even located in the insertion of the
arms. These "arms" are inserted by their basis, not on the intermediate or lateral
lamella, or external lamella (" descending crescent-shaped processes "), but on the edge
of the "ascending apparatus." Their direction is that of the lamina on which they are
supported ; and they reach, after having described the inflections already indicated, the
median point of the tongue-shaped process, where their two extremities arc located. This
arrangement is shown in PL XXIII. fig. lO, Avhich is copied from one I published first
in the 'Annals and Magazine of Nat. Hist.' for May 1852, and afterwards reproduced in
Dr. AVoodward's ' Manual of the Mollusca.' The cirri of the arms are long and flexible.

Space will not permit us to follow M. Lacaze-Duthiers in bis admirable observations in
connection with the anatomy of the animal, further than to say that he minutely describes
the position of the animal in the shell, the mantle, muscles, the organs of nutrition, the
arms and their cirri, the moutli and its lips, the liver, stomach, intestines, circvilation,
respiration, the special glands, nervous system, the male and female organs of repro-
duction, &c. He adds, that French zoologists consider, with some other naturalists,
that respiration is probably effected partly by the labial appendages, which bear a
great analogy to the gills of other Mollusca, and that he has not been able to discover
any anal aperture — a fact strongly urged by Messrs. Huxley, Hancock, Gratiolet,
and others for Terehratula and EliynclioneUa. M. Lacaze-Duthiers is of opinion that
the sexes are distinct, or, in other words, that there is a male and female animal; but
Mr. Hancock considers this to be uncertain, and is disposed to hold the opinion that the
sexes are combined in the same animal.

M. Lacaze-Duthiers concludes his elaborate series of anatomical observations with
many important details in connection wdth the embryonic condition of Thecklmm medi-
terraneuin, but states that it was not possible for him to follow out in a complete manner
every successive stage of its development. The youngest egg that he was able to
observe had already acquired a rather elongated pyriform shape, and what attracted
most notice was the large size of the cells of which it was composed, which also
contained a large quantity of granulations, of a comparatively enormous size.
The egg at this stage is very similar, at least in general appearance, to a mass of
vegetable cells full of feculse. Towards one of the extremities of the egg the connection
with the bourlet or cap of the suspensory filaments may be found, and however little

1G2 DE. T. DAVIDSOA^ ON EECENT BEACHIOPODA.

the glass slides are shaken between which the embryos are placed they become ruptured,
and the cells and granulations that they contain escape.

In the next stage which M. Lacaze-Duthiers found in the same group of young, the
embryo no longer presented a uniform mass, but was divided into two halves, one of
which, more voluminous than the other, Avas in every case found attached to the tipper
filament.

After many details which I have not space to reproduce, M. Lacaze-Duthiers con-
cludes by saying (p. 324) : — On the lower face, an embryo in the more advanced state
shoAvs four eye-shaped spots, visible in the thickness of its anterior intermediary lobe.
A distribution of yellowish matter recalls tolerably well the origin of the liver in the
Acephala or the Gasteropoda ; it is probably in the middle of these small agglome-
rations of yellowish matter that the stomach is excavated, and one may already recognize
in these series of little bundles the lobules and secretory glands of the liver of the adult
TheckUum. We have reproduced on Plate XXIII. a few of M. Lacaze-Duthiers's admir-
able illustrations of the embryo with two and four lobes.

92. Thecidium Baeeetti, Woodward, MS. (Plate XXIII. figs. 9-11.)

Thecidium Barretti, Davidson, Geol. Mag. vol. i. p. 17, pi. ii. figs. 1, 2, 3, 1864 ; Crosse, Journ. cle
Concli, 3" ser. t. vi. p. 272, 1866; Dall, Amer. Jouru. of Couch, vol. vi. p. 151, 1870, Bull. Mus. Comp.
Zool., Harvard, vol. iii. p. 42, 1871.

Shell small, somewhat pyriformly ovate, attached to marine ol)jects by a portion of the
back of its beak. Dorsal valve semicircular, flattened, and slightly convex at the umbo.
Ventral valve somewhat pyriform, very convex, deep, and thickened ; beak mode-
rately produced ; area triangular, but more or less irregular on account of the position
and extent of the attached surface. The interior of the dorsal valve is slightly concave'
with an oblong, square-shaped, prominent, cardinal process between the dental sockets.
A broad, thickened, raised, granulated margin encircles the valve, and forms a bridge
over the small, deep, visceral cavity, close to the basis of the cardinal process ; the gra-
nulations are larger and more prominent on the inner margin. On reaching the front,
near the middle, the margin suddenly cm-ves upwards on each side, and unites so as to
form a central A-shaped ascending process {[/), the attenuated extremity of which is direc-
ted towards the middle of the bridge- shaped process {h) already described in TheckUum
medUcrraneum (see PL XXIII. fig. IG). The descending apparatus (/, k) is united close
to the extremity of the central angular ascending process, and follows at a little distance
the curves of the inner margin of the same ascending process. Length and breadth
about 2 lines. Colour white.

Hah. This small and well-characterized species was obtained by Lucas Barrett at 60
fathoms off the north-east coast of Jamaica, and was found fossil by him in the newest
Pliocene beds of that island.

Ohs. In external shape Thecidium Barretti cannot be distinguished from the Mediter-
ranean species ; but its interior is very different, and resembles, in its simple arrange-
ment, that of several Jurassic forms, such as Thecidium Moorii, T. triaiKjulure, &c.

DK. T. DAVIDSON ON RECENT BRACHIOPODA. 163

Family RHYNCHONELLIDyE.

The genus BhiinchoneUa, Fisclier, 1809, and the genus Atrctia, Gwyn Jeffreys, are the
only representatives of this family found in the recent state.

The genus Mhynchonella is one of the oldest types of life, and has heen largely repre-
sented since Silurian times. Sis species are still living in tlu^ present seas, viz. : —

1. RhjiichoncUa psittacea, Clicmiiitz, 1780.

2. 7ii(jncans, Sowerby, 184-6.

3. I u eld a, iio\\\ A, 1860.

4. Rhynchonella cornea, Fischer, 1885.

5. Gray}, Wocxhviu'd, 18").").

0. Dodo/cini, Davidson, 188u.

The first two species are very abundant, the others much less so. Of the spiny Ehyn-
chonella D'dtlerlehii four specimens have heen dredged, and we are only acquainted with a
single example of lUtynchonella Grayi. The shell in all is fibrous and impunctate.
The genus Rhynchonella is characterized by a very insignificant development of internal
septa. In the ventral valve generally only dental plates are present, which do not unite
in the middle line, and in the dorsal valve an inconspicuous median septum is developed.
The hinge-plate is deeply divided, supporting two slender curved lamelke. The animal
has elongated spiral labial appendages, directed imvard towards the concavity of the dorsal
valve. Mantle not adhering, its margin fringed with a few short seta;.

93. llHTNcnoNELLA PSITTACEA, Chemnitz, sp. (Plate XXIV. figs. 1-11.)

Anomia, Lister, Hist, sive Syu. methodicae Concliylioruiu, tab. 211. fig. 46, 1685.

Bee de per roquet, Davila, Cat. Syst. vol. i. pi. xx., 1767.

Anomia ?, Lister, Couch, tab. ccxi. fig. 16, 17(58; Favanne dc Moiitcervellc, La Conchy) iologie,

pi. xli. fig. 24, 1780.

Anomia rostrum psittacea, Chemnitz, Neues syst. Couch. -Cab. vol. viii. pi. Ixxviii. fig. 713, 1785.

Anomia uquilina, Solander, MS. no. 14, 1757.

Lampas psittacei, Calonnc, Catalogue of the various articles which compose the Coll. of ]\I. de
Calonne, 1797.

Anomia psittacea, Gmeliu, Linn. Syst. Nat. p. 3319, 1788.

Anomia , d'Argenville, Hist. Nat. Conchyliologie, etc. tab. 23.

Terebratula psittacea, Bruguierc, Encyclop. Meth. pi. ccxliv. figs. 3a, 3i, 1789; Klein, Tentamen
Methodi Ostracologica-, pi. xii. fig. 84, 1753.

Ano7nia psittacea, Dilhvyn, Descriptive Catalogue of Recent Shells, p. 293, 1817.

Terebratula psittacea, Lamarck, An. sans Vert. vol. vi. p. 248, 1819.

Anomia psittacea, Turton, A Conch. Dictionary of the British Islands, p. 5, figs. 42-44, 1819.

Terebratula psittacea, Fleming, Hist, of Br. An. vol. i. p. 368, 1828.

Gijjndia psittacea, ^Meuke, Syn. Meth. Moll. p. 96, 1828-30.

Terebratula psittacea, Blainville, Diet. Sci. Nat. t. liii. p. 140, 1828 ; Miiller, Index Moll. Gronlandiae,
Nat. Tidsskr. iv. p. 76 ; Owen, On the Anatomy of Terebratula, Trans. Zool. Soc. vol. i. p. 146, pi. xxii.,
1833 ; Quenstedt, Ueber das Oeffnen und Schliessen der Brachiopodeu, Wicgraann's Archiv, Bd. ii. p. 220,
pi. iv. figs. ,1 & 6, 1835; Davidson, Ann. & Mag. Nat. Hist. ;:nd ser. vol. xvi. p. 436, 1855; Lamarck,
An. sans Vert. vol. vii. p. 333, 1836 ; Anton, Verzeichniss der Conchylien, p. 23, 1839; G. B. Sowerby,
A Conch. Manual, p. 203, 1842; Kiister, Chemnitz's Conch.-Cub. vol. vii. pi. ii. figs. 18-20, 1813;
Sowerby, Thes. Conch, p. 342, pi. Ixxi. figs. 78 80, 1846.

Hiipothyris psittacea, King, Ann. & Mag. Nat. Hist. vol. xviii. p. 238, 1846.

Hemithyris psittacea, d'Orbiguy, Considerations Zool. sur Ics Brachiopodes, Comptes Rendus, t. xxv.
p. 268, 1847.

SECOND SEllIES. — ZOOLOGY, VOL. IV. 22

164 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

Hi/pothyrispsittacea,Fovhes8i}Iaji.\ej,A History of British Mollusca, vol. ii. p. 3 IG, pi. Ivii.figs. 1-3, 1849.

Rhyncho7iella psittacea, Quenstedt, Handbuch der Petrefakteukunde, pl. 35. fig. 44, 18.51 ; Davidson,
Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 374, 18.52 ; L. Barrett, Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi.
p. 259, 1855; S. P. Woodward, A Manual of the Mollusca, p. 225, figs. 138 & 189, 1856 ; A. Adams, The
Genera of Recent Mollusca, vol. ii. p. 582, pl. cxxxii. fig. 2, 1858; A. Hancock, On the Organization of the
Brachiopoda, Phil. Trans, vol. cxlviii., 1858 ; E. Sness, Ueber die Wolinsitze der Brachiopoden, Sitzungsb.
k. Akad. Wissensch. Wien, p. 218, 1859 ; L. Reeve, Monogr. of Rhynchonclla, pl. i. fig. 2, 1861.

Hemithyris psittacea, M'Coy, Synopsis of a Classification of the British Palaeozoic Fos.sils, p. 199, 1865.

Rhynchonella psittacea, Gwyn Jeffreys, British Conchology, vol. v. p. IGl, 1869, and Proc. Zool. Soc.
1878, p. 413 ; Gould, Report on the Terebratulce of Massachusetts, p. 210, fig. 501, 1870.

Hemithyris psittacea, Dall, Proc. Acad. Nat. Sci. Philadelpliia, 1873, p. 196.

Rliynchonella psittacea, Davidson, Brit. Foss. Brach. vol. iv. pp. 8 & 16, pl. ii. fig. 5, 1874 ; G. O. Sars,
Moll. Regionis Arcticse Norvegiee, p. 9, t. i. fig. 1, 1878; Whiteaves, Canadian Naturalist, vol. viii.
no. 8, 1878; G. Dunker, Index Mollusc, maris Japonici, p. 253, 1882; Davidson, Brit. Fossil Brach.
vol. v. p. 331 etc., 1884.

Shell somewhat triangular, globose, broadest anteriorly, tapering posteriorly, lateral
margins rounded. Dorsal valve inflated, especially at the umbo, more or less divided
into three lobes, of Avbich the central one forms a mesial fold, scarcely defined in some
specimens, much more so in others ; front line nearly straight or three-lobed. Ventral
valve much less convex than the dorsal one, rather flattened, with a broad, channelled,
flattened, longitudinal mesial sinus ; beak sharply pointed, incurved, under which is
situated an incomplete elongated foramen, margined anteriorly by the umbo, and
laterally by triangular deltidial plates ; beak-ridges not sharply defined ; lateral
margins of the valves sinuous, curved in front. Surface of valves radiately and
finely striated. Shell-structure fibrous. Valves strongly articulated by curved teeth
in the ventral valve, fitting into sockets in the dorsal one. Hinge-plate in the dorsal
valve deeply divided, supporting two short, flattened, grooved and curved lamellte. At
the bottom of the dorsal valve are seen the quadruple muscular impressions left by the
adductor or occlusor muscles, each pair beiug separated by a short medio-longitudinal
ridge. In the interior of the ventral valve the teeth are supported by dental plates
extending to tlie bottom of the valve, and at their base a semicircular ridge on either
side encloses a saucer-shaped depression in which are situated the muscular scars. Close
under the beak the peduncular muscles leave a small scar ; lower down and towards
the centre of the valve is situated a divided heart-shaped scar due to the adductor or
occlusor muscles ; and on each side of these are situated, one above the other, the divari-
cator and ventral adjuster muscular impressions. The animal is provided with elongated
spiral arms, directed inwards, towards the concavity of the dorsal valve ; alimentary
canal terminates behind the insertions of the adductor in the ventral valve ; mantle not
adhering, its margin fringed witli a few short setae. Colour bluish or a brown-black.
Length 1 inch 3 lines, width 1 inch 1 line, depth 9 lines.

Rab. Bhijnchonella psittncea is circumpolar in its distribution. It was dredged in
Eranklin-Pierce Bay, lat. 79° 25' N., in 15 fathoms, and at Cape Napoleon in 15 fathoms,
by Nares's Arctic Expedition in 1875, being in fact the only Brachiopod obtained
by the ' Alert ' and ' Discovery ' in those polar regions. R. psittacea abounds in the

DR. T. DAVIDSON ON EECENT BEACHIOPODA. 165

Norwogian Seas, from Drontheim to the North Cajie ; off Shetland ; Grand Greve, Gaspav
Bay, Canada East ; Unalashka to Shumagins in the Aleutian Chain (Dall) ; Banks of
St. Margaret Bay; Russian Lapland to Sitka; from Behring Strait to Japan in North
Pacific; in the Gulf of St. Lawrence, Canada, and in several other places.

Fossil. It occurs in the Upper Tertiaries of Great Britain, Ireland, Scandinavia, Canada,
Sicily, south of Spain, &c.

Obs. Until 1S()9, when Fischer de Waldheim proposed his excellent genus Ithijncho-
nella, the shell under description had been described under the fancy and generic names
of ''Bee de perroquet,'" Anomia and Terebratiila; since then sometimes by those of
Hemithyris, Hypothtjris, Lampas, and Gi/pidea ; but Fischer's name Rhynchonella is the
generic designation by which the shell has been generally known, and that which should
hold priority over all others.

Rhynchonella psUtacea does not vary very much in external shape ; young specimens
are, however, more triangular, less convex, and with a more elongated triangularly shaped
beak. The dorsal valve in some adult examples is uniformly convex, while others show
a well-defiued mesial fold. The intimate structure of the shell of Rhynchonella has been
carefully studied, described, and illustrated by Dr. W. B. Carpenter in various jiapers.
He says : — " No one who examines the shells of the Recent Rhynchonella psittacea and
Rh. nigricans, even in the most superficial manner, can have any hesitation in recognizing
the entire absence of the superficial ' punctuations ' which mark the orifices of the shell-
canals in the recent species of TevebratuUdce; and the most careful microscopic exami-
nation of these sections of the shell, taken from any part and in any direction, does but
confirm this conclusion. ... In all other respects the intimate structure of the shell cor-
responds precisely with that of Terebratulidce ; but it may be mentioned that the prismatic
laminoD are less adherent to each other than in the perforated shells, so that they are
readily split asunder." (' On the Intimate Structure of the Shells of Brachiopoda,'
Palseontological Society, p. 35, 1851.)

The animal of R. psittacea and its anatomical characters were carefully described
by Richard 0^ven in 1833, and especially by Albany Hancock, in his admirable
memoir " On the Organization of the Brachiopoda," in the Philosophical Transactions of
the Royal Society for 1858. 'Wq arc likewise indebted to Prof. T. H. Huxley for several
valuable anatomical details published in vol. vii. of the Proceedings of the Royal Society
for 1854, as well as to several other distinguished zoologists. In 1835 Quenstedt, in
Wiegmann's Archiv, Bd. ii. p, 220, founding his views on very precise reasons derived
from the mode of attachment of the valves in Rhynchonella psittacea, pointed out the
two orders of muscles, of which one closed, while the other opened the valves.

Mr. Lucas Barrett informs us that he found Rhynchonella psittacea A-ery difficult to
exaiuine, the animal being extremelv timid and closed its valves on the slightest move-
ment ; the coiled arms are extended, so that the cirri come as far as the margin of the
shell, but it never protruded its arms *.

In Rhynchonella psittacea, as well as in other species of the genus, the elongated spiral
appendages are supported at their origin only by two short, curved, projecting calcareous

* Annals & Mag. Nat. Hist. 2nd ser. vol. xvi. p. 259, 1855.

22*

166 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

jirocesses ; they can bo uurolled at the will of the auimal and protruded to some distance
beyond the margins of the valves, contrary to the statement made by Barrett. When
forci])ly stretched out they are said to be more than four times the length of the shell,
and support some 3000 cii'ri. In a note on the extension of the coiled arms in Rhyn-
chonella j:>si(tacea, published in the ' Amer. Journ. Sci. & Arts,' 3rd ser. vol. xvii. 1879,
p. 257, Prof. Morse says : — " Years ago von Buch recorded that Otto Erederic Miiller had
observed Rliijnclionella j^sittacea protrude its arms beyond the anterior borders of the
shell. This single observation was not widely accepted, and many doubted the possibility
of the arms being exerted in this manner. In the year 1872, Avhile studying living
Rliynchonella in the St. Lawrence, I observed a specimen protrude its arms to a distance of
four centimeters beyond the anterior borders of the shell, a distance nearly equaling twice
the length of the shell. This year I again had an opportunity of studying Rhynclionella in
Hakodate, Yesso, and again observed the same features. Specimens lying on the bottom of
a glass dish protruded their arms a short distance, and remained in this position for hours.
.... The movements of the arms were very sluggish, though the cirri were constantly
in motion. Sometimes the shells closed upon the arms before they were retracted."

In 1833 Owen [1. c.) gave a figure in illustration of the arms, one of which has been
artificially unfolded. Space will unfortunately not admit of my reproducing all the
admirable details in connection with the anatomy of R. j^s/ttacea so well described and
illustrated by A. Hancock ; we will, however, refer to the most important features.

" In Rhynchonella psittacea (p. 799, I. c.) the general disposition of the muscles is the
same as in W. mistralis, only they are longer and more slender, particularly the occlusors,
Avhich, with the exception of their extremities, are thin and tendinous. The surfaces of
attachment also vary a little in form, as can be readily seen on removing the shell. The
extremities of the muscles are then observed, as usual, at the ventral surface of the
animal, clustered together, a little in advance of the umbonal region. The occlusors are
almost colourless, narrow and elongated, and have their anterior margins united on the
median line ; posteriorly they diverge, leaving a space between them, in Avhich the
terminal extremity of the intestine is seen. The divaricators are very large, and are
placed external to, and in contact with, the occlusors ; they are broad and fan-like in front,
exhibiting radiating divisions, and meet on the median line, in advance of the occlusors.
Behind they are produced and pointed. The ventral adjuster muscles have their
extremities narrow and much elongated ; they rest agaiust the external margin of the
divaricators, are enlarged a little, and converge posteriorly. Unlike Waldheimia, there
is here a pair of peduncular muscles seen at the sides of the umbo, having between
them the accessory divaricators, which are of a somewhat triangular form. The dorsal
terminations of the occlusors present nothing remarkable in their appearance. All the
extremities of the muscles seen at the surface of the animal are of a yellowish-red coloux*,
except those of the peduncular muscles and the ventral terminations of the occlusors . . .
The muscles (l. c. p. 805) in the Terebratididce and RhynGlionellklce are peculiar for their
enlarged, fleshy extremities, and for the attenuated, tendinous character of their inter-
mediate portions . . .

*' The arms [p. 802] of R. psittacea are totally deprived of calcareous support except at

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 167

their origin, where they arc sustained by tlie two lunye-processes, or oral lamina.', the
points of which reach as far forward as their external margins. They fill up the greater
portion of the pallial chamber ; and in their arrangement accurately resemble the cal-
careous spirals of Atrijpa reticularis, a Silurian fossil, only their approximate sides are not
flattened. The arm throughout is composed of a slightly depressed tube or canal, carrying
along its outer margin the semi-cartilaginous grooved edge, bearing the fringe of cirri as
in W. auslrails. The brachial fold in front of the groove is largely developed, and com-
pletely overlaps it. The tube or the great brachial canal terminates at the side of the
oesophagus in a delicate membranous sac of no great extent, which projects into the
perivisceral chamber, as first noticed by Prof. Huxley . . .

" The parietes of the great canal are somewhat stouter than in W. australis ; the mus-
cular fibres, however, are arranged in the same manner as in it, but are more numerous,
particularly the longitudinal ones, which form a well-defined band towards the proximal
extremity of the arm .... A large development of the brachial apparatus seems
necessary in the economy of the animal, and the various ways in which it is folded up
and disposed within the pallial chamber are only so many methods of arranging within a
limited space the requisite extent of organ."

Mr. Hancock seems to doubt the unrolling and projection of the arms in Hhynchonella
or that the arms arc in any way instrumental in opening the valves.

" In H. psiltacea [p. 814] the disposition of the alimentary canal is the same as iu the
Terebratulida}. The oesophagus is, however, considerably longer than in Waldheimia, the
mouth approaching much nearer to the ventral valve. The liver is larger than usual,
and the hiliary secretion is conveyed through the lateral walls of the cardiac extremity
of the stomach by four short ducts, two at each side, one being placed a little in advance
of the other.

"The intestine is rallier long and gradually tapers downwards. On reaching the
ventral valve, directly behind the extremities of the occlusor muscles, it turns backw^ards
and upwards, and, detaching itself from the mesentery, advances a little, and ter-
minates in a much enlarged, rounded extremity, which inclines to the right or
left, varying in this respect in different individuals. The termination projects freely
into the centre of the perivisceral chamber, and here, as in the TerehralHlldoi, there
is no anus ; the bulbous enlargement is entire, exhibiting no opening whatever. . . .
In BhynchoHella the gastro-parietal and ilio-parietal hands, jiarticularly the latter, are
longer than in Wcddheimia .... The reproductive organs [p. 818] have much the same
disposition iu Rhi/nchonella psittacea [as in the other Terebratnlidce], but the dorsal
genital sinuses arc not connected with the so-called vascular trunks, while the ventral
are. The genital band, too, which is yellow, is much more closely convoluted, having
sometimes almost the appearance of being fused into one mass, the interstices being just
sutficient to permit the passage of the muscular ties, which are stout, and are arranged in
imperfect longitudinal and diagonal lines. These ties give a granulated or pitted
appearance to the ovarian impression in the shell, and are worthy of the attention of
the palaeontologist. . . .

" There are two of these oviducts In all the Brachiopods that have come under my

168 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

observation, except in Rhynchonella, in whicli there are four, as first pointed out by

Prof. Huxley two [p. 821] within the ventral, and two within the dorsal valve ;

both paii's are precisely similar, and are of a yellowish colour .... The central portion
of the blood-system in Rhynchonella is arranged much as in the Terchratulldce .... In
a. psittacea [p. 829] tlie setae are slender, short, and finely pointed ; they vary in length,
as they do indeed in all the species, and occasionally three or four issue out of one
follicle .... The great cavity [of the perivisceral chamber], placed close to the hinge of
the valves, in which the viscera are lodged, is limited above and below by the dorsal and
ventral walls of the body, and in front by the inflections of the inner laminae of the pallial
lobes." In conclusion, Mr. Hancock describes at great length the nervous sj^stem, to
which we cannot refer.

Rhynchonella psittacea, var. Woodwardi, A. Adams. (Plate XXIV. figs. 12-13.)

Rhynchonella Woodivardii, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 100, 1863.
Rhynchonella psittacea, var. Woodwardi, Davidson, Proc. Zool. Soc. 1871, p. 309, pi. xxxi. fig. 12.

Mr. Adams states in his paper that " this species differs from R. psittacea in being
concentrically striolate instead of radiately grooved ; the beak, moreover, is smaller and
less curved ; the foramen is more broadly triangular, and the ventral margin rounded and
produced in the middle. The young possess the same characters seen in more adult
specimens."

Hah. Gotto, 48 fathoms ; also off Ptifunsiri Islands, four miles from the shore, in
35 fathoms, from a bottom of coral, broken shells, and stones.

I have been able to examine two examples of this shell, given to me by Mr. Adams,
and could distinctly perceive faintly radiating striae, similar to those that cover the surface
of B,. psittacea. I cannot help thinking, and am confirmed in this opinion by Dr. Gwvn
Jeffreys, that thei?. Woodioardi of Adams is no more than a local variety of i?. psittacea.

The specimens obtained by Mr. Adams are of a less bluish tint than we find usually
in the shell last named, but some examples from the Northern European seas have also
assumed tliat colour.

94. Rhynchonella lucida, Gould. (Plate XXIV. figs. 14-15 h.)

Rhynchonella lucida, Gon]d,'Proc. Boston Soc. Nat. Hist. p. 323, 1800; Otia Concli. p. 120; and
Proc. Boston Soc. Nat. Hist. vol. vii. p. 323, 1871 ; E. Suess, Ueberdie Wolmsitze der Brachiopoden,
Sitzungsb. k. Akad. Wissensch. Wien, p. 219, 1859 ; A. Adams, Ann. & Mag. Nat. Hist. 3rd ser.
vol. xi. p. 100, 1863; Dall, Amer. Journ. of Conch, vol. vi. p. 153, 1870; Davidson, Proc. Zool. Soc.
p. 309, pi. xxxi. figs. 13-1 1, 1871.

Hemithyris lucida, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 196, 1873.

Rhynchonella lucida, G. Duuker, Index Moll, maris Japonici, p. 253, 1882.

Shell small, obtusely subrhomboidal or ovate, rather longer than wide. Dorsal valve
convex, almost gibbous ; mesial fold wide, commencing to rise at about half the Icns-th
of the valve. Ventral valve rather less convex, or deeper tlian the opposite one, and
scooped out near tlie front in the form of a rather deep sinus. Peak acute, sharply
incurved ; foramen beneath the angular extremity of the beak, completed by a deltidium.
Surface smooth ; shell-structure fibrous. Colour light glassy grey. Length 6 lines, width
5 lines, depth 3 lines.

DR. T. DAVIDSON ON EECEXT BRACHIOPODA. 169

Sab. Dr. Gould's specimens wcro tlrodyed off the coast of Japan, lat. 30° 35' N., loni?.
130° 40' E., in 100 fathoms, sand, by Capt. Stevens of the ' Hancock,' and by A. Adams
at Satanomosaki in 55 fathoms, and at Gotto in 48 fathoms.

Obs. This very interesting species was first discovered by Dr. Gouhl, liut ho does not
appear to have figured it. I did so, however, in 1871, from specimens given to me
by Mr. Adams. In his description. Dr. Gouhl observes that his shell, which might be
taken for a small Terebmtula citrea, is very thin and delicate, and further distinguished
by the absence of punctures.

95. RuYNCHONELLA Grayi, Woodvvard. (Plate XXV. figs. 1-1 c.)

Rhiinrhonella Grayii, S. P. Woodward, Ann. & Mag. Nat. Hist. 2nd scr. vol. xvi. p. 141', pi. x. figs. 16-
]()f;, 185"); E. Suess, Ueber die Wohnsitze der Brachiopodcii, Sitzuugsb. k. Akad. Wlsscusch. Wien,
Bd. xxxvii. p. 219, 1859; L. Reeve, Conch. Icon., Monogr. of Rhynchonc/la, pi. xi. fig. 3, 1861; Dall,
Amer. Joui-n. of Conch, vol. vi. p. 153, 1870.

Hcmitliyris Grayi, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 196, 1873.

" Shell light horn-colour, dull, trigonal, depressed ; sides rounded, front truncated ; beak
small, acute; valves smooth, obscurely marked by lines of gro^\-ih, and strongly plaited
near the margin with four central plaits and three or four on each side, the furrows
obscurely striated; margins of valves sinuated in front and strongly toothed; foramen
minvite, completely tubular. Length nearly 8 lines, by G^ in breadth and 4 in depth.

" This interesting and at present unique shell was sent, with other natural-history
objects, from the Feejee Islands by J. M'Gillivray, Esq., Xaturalist to the Surveying
Expedition under Capt. Deuham, of H.M.S. 'Herald.' No particulars as to its habitat
have been received. It differs from the known species of living Rhynchonella in its
lightness of colour, the others being black ; in the plication of the borders of its valves,
which reminds us of the fossil Bh. subplicata (Mantell), and Rh. lineata, Philippi, and
especially it differs in having a foramen quite separate from the hinge-line, by the deve-
lopment and union of the two elements of the deltidium, in this respect agreeing with the
ordinary adult condition of the fossil RhynchonelUe. Were it not for the remains of the
pedicle and traces of the mantle in its interior, we might have taken it for a pliocene fossil,
being exactly similar in its colour and dull transj)arency to the specimens of Rh. psittacea
found in the Crag at Norwich. The muscular impressions arc like those of the type, and
the interior has traces of unsymmetrical vascular markings."

The above description was sent to me for pul^lication in 1855 by my valued and
eminent friend Dr. S. P. "Woodward ; and I added figures of the shell to my paper " On
Brachiopoda " pubhshed in the Ann. & Mag. Nat. Hist, for 1855. Singularly enough, no
other example of the species has been discovered. The type forms part of the collection
of shells in the Zoological Department of the British Museum.

96. Rhynchonella nigricans, Sowerby. (Plate XXIV. figs. 10-19.)

Rhynchonella mgricans, G. B. Sowerby, Proc. Zool. Soc. 18 IG, p. 91, and Thesaurus Conchyliorum, i.
p. 342, pi. Isxi. figs. 81, 82, 18J.6; Davidson, Proc. Zool. Soc. 1852, p. 81, jjI. xiv. figs. 30, 31, and Ann.
& Mag. Nat. Hist. 2nd ser. vol. xvi. p. 415, pl. x. fig. 18, 1855 ; E. Sucss, Ucber die Wohnsitze dcr Bra-
chiopoden, Sitzungsb. k. Akad. der Wissensch. Wicn, p. 220, 1859 ; L. Reeve, Couch. Icon., Monogr. of

170 DR. T. DAVIDSON ON RECENT BRACHIOPODA.

RhynchoneUa, pi. i. fig. 1, 1861 ; E. Sucss, Fossile Mollusken aus Ncu-Sielaiul, Novara Exped. Geol.
Theil, Bd. i. Abth. 2, p. 60, pi. xiv. fig. 6, 1864; Dall, Amer. Journ. of Conch, vol. vi. p. 152, 1870 ;
Hutton, Catalogue of the Marine Mollusea of New Zealand, 1873, p. 87.

Hemlthyris mgricans, Dall, Proe. Acad. Nat. Sci. Philadelpliia, 1873, p. 196.

RhynchoneUa nigricans, T. W. Kirk, List of Marine Mollusea found iu the neiglibourliood of Welling-
ton, Transactions New Zealand Institute, vol. xii. p. 303, 1880.

Shell somewhat tetrahedral, wider than loug. Hinge-line obtusely angular. Dorsal
valve convex, divided into three lobes, of wliich the central one forms a broad, slightly
raised mesial fold. Ventral valve rather less deep or convex than the dorsal one, with a
broad mesial sinus commencing at about a third of the length of the valve and extending
to the front; beak pointed and slightly incurved ; foramen longitndiually oval, incom-
plete, and situated under the extremity of the beak, margined anteriorly by a small
portion of the umbo and laterally by narrow deltidial plates ; beak-ridges tolerably well
defined, leaving between them and tlie hinge-line a narrow triangular flattened space.
Surface of valves ornamented by a variable nvimber of angular ribs, from twenty to
twenty-live on each valve, a few of which are due to interpolation, while from five to six
occupy the fold and sinus. Surface of valves crossed by numerous concentric lines, or
projecting ridges, of groAvth. Colour bluish or brownish black ; shell-structure fibrous,
impunctate. The apophysary system consists of two short curved lamellae. Length
11 lines, breadth 13 lines, depth 7 lines.

Hah. Five miles east of Ruapuke Island, New Zealand ; dredged by Mr. F. J. Evans,
R.N., in 19 fathoms, on rock and coral. Abundant at Faveau Strait, and not un-
common otr the south Chatham Islands (Hutton).

Fossil shells referred to this species have been found in New Zealand.

Ohs. Our first knowledge of this most interesting species is due to G. B. Sowerby,
Avho says that, at the time he was describing the shell, only one small young specimen,
without indication of locality, was known, wliich was found in the collection of the late
G. Humphrey. Since then a number of specimens of all ages have been dredged and may
be seen in many collections. In 1882 I I'eceived from New Zealand several examples, and
redescribed and figured the species.

When quite young, and up to a certain age, the shell is triangular and somewhat
compressed, and many adult examples are unsymmetrical, from the fold and sinus being
moved more to one side than the other. The yoving shells are often found attached in
groups to an adult example, or to a sponge or rock.

The striking resemblance presented to more than one Jurassic or Cretaceous species of
RhynchoneUa is very remarkable. Some fossil specimens of 11. nigricans described by Prof.
Suess from Kohuron in New Zealand measured 13 lines in length by 14 in breadth.

97. Rhynchonella nigricans, var. pyxidata, R. B.Watson, MS. (Plate XXIV. fig. 20.)

RhynchoneUa nigricans, var. jjixydata, Davidson, Report on tlie Bracliiopoda, Voyage of H.M.S.
' Cliallenger,' Zool. vol. i. p. 59, pi. iv. fig. 14, 1880.

Var. pyxidata. Shell transversely oval, widest anteriorly, tapering posteriorly, wider
than long. Dorsal valve uniformly convex to about half its length, where a broad mesial

DR. T. DAVIDSON ON KECENT BRACHIOPODA. 171

fold, scarc(;ly raised above the general convexity of the valve, occupies ihe anterior half
of the valve. Ventral valve rather less deep and convex than the opposite one, with a
broad well-defined mesial sinus, commencing at a short distance from the extremity of
the beak and extending to the front ; beak rather small, acute, and incurved ; foramen
incomplete, situated under its pointed extremity, laterally margined by narrow deltidial
plates ; surface of both valves ornamented Avith about forty to forty-six small, am^^ular,
radiating ri])s, closely intersected by equidistant, squamose, concentric I'idges of growth,
giving an imbricated appearance to the surface. Colour whitish, sometimes brownish,
especially at the beaks. Length 9 lines, breadth 10 lines, depth 0 lines.

Hah. Six examples were dredged by tlie ' Challenger ' Expedition south of Kerguelen
Island, associated with numerous specimens of JFaldheimia kerguelenensis ; at a depth
of 150 filth oms.

Ohs. Nearly all the specimens of tlie typical forui from Faveaii Strait were of a blue-
black or brownish colour, while the six examples of the variety pyjcidata dredged by the
' Challenger ' Expedition were of a light yellowish-white colour ; but as one showed at
the beaks the brown tint of the New-Zealand type, it is probable that some specimens of
the variety were also of a light brown colour. Tlie ribs in the latter are likewise more
numerous and smaller. These differences, no doubt, led the Rev. E,. Boog Watson to distin-
guish it as a distinct species under the MS. name o? pi/xidaia, from Trvz,iov, as he thought
it like a box in form. After careful study and comparison with an extensive series of
New-Zealand types, I am led to the conclusion that Bhynchonella pyxklata is merely a
local variety of R. nigricans. A species of Bhynchonella recently found by the Rev. J. E.
Tenison Woods in the Tertiary rocks of Table Cape, Tasmania, seems absolutely undistin-
o-uishablc. It has received the MS. name lihynchonella ccclata from Prof. M'Coy, and
was described under that name by the Rev. Tenisou Woods in a paper on the Tertiary
deposits of Australia, published in the ' Proceedings of the Royal Society of New South
Wales' in 1877.

98. Rhynchonella. coknea, P. Fischer, MS. (Plate XXV. hgs. 2-4.)
? Rhynchonella sicula, Gwyn JefEreys, Proc. Zool. Soc. 18~8, p. 113, pi. x\iii. figs. 5, G.
Shell thin, ovately triangular, broadest anteriorly, tapering posteriorly, rounded
laterally, very slightly so in front. Dorsal valve moderately convex, without either fold
or sinus, slightly depressed along the middle. Ventral valve ratlier deeper and more
convex than the opposite one, and slightly depressed from the middle of the valve to the
front ; beak short, incurved, with a small circular incomplete foramen uiidcu- its angular
extremity, and laterally margined by narrow deltidial plates ; margins gently tiexaous,
and slightly curved in front. Surface of valves covered with numerous close-set very
fine longitudinally radiating striie, and crossed by a few fine concentric lines of growth ;
shell-structure fibrous. Colour pale brownish yellow. Valves articulating by means
of small teeth and sockets. In the interior of the dorsal valve the hinge-plate is
divided along the middle, with a mecUan groove along each of its parts, from which
extend two thin curved lamellse denticulated at their extremity; undi-r the hinge-plate

SECOND SERIES. — ZOOLOGY, VOL. IV. 23

172 DK. T. DAVIDSON ON EECENT BllACHIOPODA.

a uarrow ridge-like septum of small elevation extends to about one third of the length
of the valve, and on each side of the septum on the bottom of the valve are situated the
quadruple impressions of the adductor muscle. Length 1 inch 1 line, breadth 1 inch,
depth 7 lines.

Mab. English Channel, depth 690 fathoms (Gwyn Jeffreys) ; olf Cape St. Vincent
(' Talisman ' Expedition), depth 57^ fathoms.

Obs. In 1870, during the ' Porcupine ' Expedition, Dr. Gwyn Jeffreys obtained, in the
chops of the English Channel, one perfect living specimen and two incomplete valves of
a Bhynclionella which he thought might be the living representative of the fossil Plio-
cene Rlnjnchonella sicula of Seguenza, and he asked me to figure it for his paper published
in the ' Proceedings of the Zoological Society ' for 1878. He says : — " The shape of the
Sicilian fossil is rather more broadly triangular, and is viuiformly convex ; but it agrees
with the recent specimen in its peculiar structure, want of flexuosity in the front margin,
short beak, and small foramen. The fibrous texture of the shell is much softer and
looser than that of i^. imttaceay He adds that the " body is whitish, gelatinous ; mantle
not furnished at its edge with setae or bristles, as is the case in the Terebratulidae ;
arms fringed with short cirj-i, which are unequal in length and curl inwards at their
extremities ; byssal plug (peduncle) small, cylindrical, and slender ; its outer case or
sheath is chitinous, and resists the action of liquor potassye."

I have seen only three examples of the recent shell ; they are, however, much
larger than the specimens of H. sicula that have been forwarded by Signor Seguenza
for my examination. Dr. P. Eischer has also written to me that he thinks the iden-
tification of the recent form with the fossil one is so uncertain that he proposes to
give it the distinctive name of cornea, which I have therefore provisionally adopted. The
specimens dredged off Cape St. Viucftnt by the ' Talisman ' Expedition are larger than
those obtained by Dr. Gwyn Jeffreys in 1870.

09. Rhynchonella Doderleini, Davidson. (Plate XXV. figs. 14, 15.)

Rhynchonella DUderleiiii, Davidson, Ann. & Mag. Nat. Hist. 5tli ser. vol. svii. p. 1, 1886.

Shell transversely subpentagonal, wider than long ; hinge-line obtusely angular.
Dorsal valve deep, posteriorly uniformly convex, anteriorly divided into three lobes, the
central one forming a broad rounded mesial fold varying in elevation according to the
age of the individual. Ventral valve much less deep than the dorsal one, with a broad
mesial sinus of greater or less depth, commencing at a third of the length of the shell
and extending to the front. Beak moderately produced, almost erect, with an oval-
shaped foramen situated under its gently incurved angular extremity, and margined by
narrow deltidial plates. Lateral margins of the valves slightly sinuated, and forming in
front a more or less elevated curve. Surface of valves marked with numerous delicate
radiating ribs, with interspaces between them of almost equal width, and increasing in
number at variable distances from the beaks by the interpolation of shorter riblets.
Ribs numbering, in full-grown specimens, sixty, close to the margin. Valves closely
crossed by numerous equidistant, concentric, raised or foliated lines of growth, giving rise
at the margin on each riblet to short sloping or erect hollow spinules. Sliell-structure

DE. T. DAVIDSON ON KECENT BEACUIOPODA.

173

Fig. 19.

fibrous. Colour liglit yellowish grey. lu the interior of the dorsal valve are two short,
curved lamella? for the support of the labial appendages. Length
12 lines, breadth 13, depth 7 lines.

Hnb. Dredged by Dr. L. Doderlein, in about 160 fathoms, in
Sagami Bay, Japan.

Obs. We are indebted to Dr. L. Doderlein for the discovery of
this very remarkable recent form of Bhynchonella, and he kindly
forwarded for my inspection and description the four examples
he procured during liis dredgings in Japanese waters. When
young the shell is flattish, neither fold nor sinus being yet de-
veloped ; the ribs are also few in numljcr, and the spines have
not yet been formed. In external appearance and size it bears
some resemblance to the Jurassic Rhynchonella sjjijioaa ; but in
this last-named species the spines are very much longer and irre-
gularly implanted on the ribs, while in H. Doderleiiil they are

arranged in rows.

It is with much pleasure that I name this very interesting
species after its discoverer.

A. Adult It Dbderhini,

Davidson.

B. Portion of external

surface, cnlarj^cd, to
show ribs, inter-
spaces, concentric
lines, and siiines.

Genus ATRETIA, Gwyn Jetfreys, 1870.

Type Atretia r/novioii, Gwyn Jeffreys.

Only two species of this genus have been discovered. The characters of the type,
A- gnomon, are fully given in tlie description of the species.

100. Atretia gnomon, Gwyn Jeffreys. (Plate XXV. figs. 0-13.)

Cryjttopor a gnomon, Gywn Jeffreys, Nature, vol. i. p. 13G, 1869.

Atretia gnomon, Gywn Jeffreys, Preliminary Report of the Scientific Exploration of the Deep Sea in
H.M.S. Surveying Vessel 'Porcupine,' Proc. Roy. Soc. vol. xviii. p. 421, 18G9; Ann. & Mag. Nat. Hist.
4th ser. vol. xviii. p. 251, 187fi, and Proc. Zool. Soc. 1878, ])p. 112, 41.3, pi. xxiii. figs. 4, 4«, 4 6.

Dimerella gnomon, Dall, Proc. Acail. Nat. Sci. Philadelphia, 1873, p. 197.

Atretia gnomon, Davidson, Suppl. to the Recent and Tertiary Brachiopoda, Brit. Foss. Hracliiopoda,
vol. iv. p. 7, 1874.

Shell very small, triangularly oval or pear-shaped, widest and rounded anteriorly,
tapering posteriorly, somewhat compressed, thin, white, semitransparent. and glossy.
Dorsal valve slightly convex, with a shallow longitudinal depression commencing at
about half the length of the valve and extendini? to the front. Ventral valve sli"htlv
deeper than the dorsal one, with a wide slightly raised mesial fold commencing at about
half the length of the valve, and extending to the front ; beak moderately produced,
angular at its extremity, moderately incurved, with a triangular incomplete foramen
commencing under the extremity of the beak, margined anteriorly by tlu; umbo of the
dorsal valve, and laterally l)y narrow rudimentary deltidial plates. Surface smootli,

23*

174 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

raarked only by some fine concentric lines of growth. Shell-structure composed of
numerous close-set microscopic imbricated scales. There is a small cardinal process seen
in the interior of tlie dorsal valve, from the base of which extends, to about half the length
of the valve, a mesial septum or large vertical blade-like plate. This rises gently by an
upward curve until it attains its higiiest elevation, then presents a short horizontal line,
to be again abruptly curved inwards until it reaches the bottom of the valve. On each
side of the cardinal process a narrow, small hinge-plate is seen, from which extend two
short, slender, curved lamellae denticulated at their extremities ; and at the bottom of the
valve on each side of the septum well-defined muscular scars are situated. In the
interior of the ventral valve two short but strong, diverging dental plates are joresent.
The valves are feebly articulated by means of small teeth in the ventral valve and
sockets in the dorsal one. Length 2i lines, breadth 2, depth 1 line.

Hab. This species was di-edged by Dr. Gwyn Jeffreys in Davis Strait, during the
'Valorous' Expedition, at depths between 1100 and 1750 fathoms, and during the
' Porcupine ' Expedition, in from 1380 to 1443 fathoms ; and during the Norwegian North-
Atlantic Expedition, at about thirty miles west of Tromso, on the slope of the banks in
the cold area in 650 fathoms (Eriele).

A single living specimen occurred in lat. 63° 9' N., long. 56° 43' W., at a depth of 1100
fathoms. Valves and fragments were also found in lat. 59° 10' N., long. 50° 25' W., and
in lat. 66° 11' N., long. 37° 41' W., at depths of 1750 and 1450 fathoms. Imperfect
specimens had been dredged by Dr. Jeffreys during the ' Porcupine' Expedition of 1869,
at Stations 20 and 30, at depths of 1443 and 1380 fathoms, off the west coast of Ii*eland.
Atretia gnomon was also obtained by the ' Talisman ' Erench Expedition off Morocco
and the Canaries, at dejiths of from 50 to 65 fathoms.

Obs. Since publishing my restored figures of this small species in the Paheontogra-
phical Society's volume for 1874, from ten to fifteen * complete examples have been
obtained by Dr. Gwyn Jeffreys and by the Marquis de Eolin, and I have been able
to ascertain that my figures, restored as it were, were quite correct. None of the
examples exceeded the dimensions given. The presence of the internal septum is indi-
cated on the exterior of the dorsal valve by a dark line. Dr. Gwyn Jeffreys observes in
his paper published in 1878 : — " According to Mr. Dall, Atretia is a synonym of Ziltel's
genus Dimerclla (Dunker and v. Meyer, Palreont. 1870, p. 220), which is a Jurassic Bra-
chiopod ; but, although it belongs to the same family, the internal apparatus is different,
and the beak is prominent in Atretia and incurved in Dimerella. The septum in Atretia
is short, gnomon-shaped, and central ; in Dimerella it extends from below the beak to
the front of the lower or smaller valve. The genus Mannia of Dewalque (Soc. Malac.
Belgique, 1874), from the ' sable noir,' or Upper Miocene of the Antwerp Crag, is also a
Rliynchonellidan ; but the internal apparatus is likewise different from that oi' Atretia."

* [About fifty specimens of Atretia gnomon were dredged by Dr. Herman Friele during the Norwegian North-
Atlantic Expedition, but no species of BhpicJionella occurred at the same station or in corresponding depths. — A. C]

DR. T. DAVIDSON ON RPXENT BEACIUOPODA. 175

APPENDIX.

Atretia Brazieri, Davidson. (Plate XXV. figs. 10-17 a.)

Atretia Brazieri, Davidson MS.; .\gnes Craue/Proc. Zool. Soc. 1880, p. 18.'5.

[Note. — This species was received by Dr. Davidson, and named in manuscript sliortly before his death.
A short description was published by me to secure priority for the name Atrelia Brazieri, wliich
Dr. Davidson had given it, after Sir. John Brazier of Sydney, who dredged eleven specimens in the
harbour of Port Stephens, New South Wales. — A. C]

This pretty little Brachiopod presents all the well-marked characteristics of the genus
Atretia. Two short, curved, slender processes, denticulated at their extremities, descend
from the small narrow hinge-plate of the smaller dorsal valve, and an elevated wedge-
shaped projection rises abruptly from the central mesial se])tuni of the same valve : the
presence of this septum is indicated by a dark line visible from the exterior of the shell.
The shell is small, generally longer than wide, triangular in shape, especially in the
younger specimens. Dorsal valve rounder than, and not so large as, the ventral one,
slightly convex, flcxuons towards the centre at the margins ot the valves. The ventral
valve, owing to the prolongation of the beak-area, is longer and more triangular than the
dorsal one, raised towards the beak, which is somewhat produced and incixrved, with a
triangular foramen commencing beneath its pointed extremity. Two elevated ridges
extend from the shoulder of the shell nearly to the margins of the valves, and there seems
to be a slight elevation corresponding to the well-marked external depression, and sur-
rounded by muscular scars, in the interior of the two specimens I have examined under
the microscope. The shell is shallow towards the margins, but rounded and deeper near
the beak. Shell-substance imperforate. Surface smooth, glossy, and gleaming, marked
with fine concentric lines of growth, semitrans})arent, horn-coloured, or light grey.
Length '1\ lines, width 1^, depth 1 line. Another specimen measured 2 lines in length
by 2j lines in width ; this was more flattened and depressed, and the external mesial
sinus in the ventral valve was less naarked. Other specimens were aljout 1 line in length.

When examined under microscopic power the scaly structure of the shell is very
apparent ; there are no perforations. The circular and elongated sac-like aggrega-
tions apparently result from the partial overlapping of the cycloidal shell-scales. The
presence of parallel rows of spicular projections was revealed in the interior of the shell ;
these recur at regular distances from each other, running from the l)eak to the margins
of the valves.

Hah. Eleven specimens and odd valves were obtained by Mr. John Brazier off Cabbage-
Tree Island, Port Stephens, New South Wales, in 25 fathoms, on sandy mud.

Obs, Five of these specimens Mr. Brazier forwarded to Dr. Davidson in July 1885.
Dr. Davidson examined them, made drawings, and named the species after Mr. Brazier,
to whom he was indebted for much information concerning the recent Australian
Brachiopoda, as he has frequently stated in this monograph.

17(i DE. T. DAVIDSON OX EECENT BEACHIOPODA.

DESCRIPTION OF THE PLATES.
Plate XIII.

Figs. 3-9 a. Terebratella coreanica, Adams aud Reeve, sp. 3. Type specimen figured by Reeve. 4-4 c. A
fine aud large specimen. 5, 5 a. A still larger example {Terebratula miniata, Gould), drudged
by L. V. Schrenk, from Hakodadi, Japan. 6, (Sa. An elongate globose variety, dredged by Capt.
St. John in Tsuga Strait. 7. Interior of dorsal valve, to show loop. 8, 8 a. Elongate variety
[T. Botic/uadi, Dayldson). 9,9a. Var. 5r;McAarrfi, Davidson. Specimens 4, 5, 6, 7, and 8, in
the Davidson Collection, Geol. Dept., British Museum ; 9, in the Zool. Dcpt., British
Museum.

Plate XIV.

Figs. 1-8. Terebratella cruenta, Dillwyn, sp., of different forms and ages; from Cook's and Faveau Straits,
New Zealand. All in the Davidson Collection, Geol. Dcpt., British Museum. \,la,\b. Avery
large and fine example. 2. An elongated form. 4. Interior of dorsal valve, showing the loop.

8. A young specimen, showing a modification in the loop. Another modification is represented
in figs. 5 ff, 5 6, which was described under the name of Terebratella Evansii, but it is really a
young form of Terebratella cruenta.

Figs. 9-19. Terebratella dorsata, Gmelin, sp. Different forms and ages ; chiefl}' from Magellan Straits.

9, 9 a, 9 6. A large specimen {T. magellanica, Chemnitz). Figs. 11, 11 «. Terebratella chilensis,
Brodcrip. 14. Represents the Terebratella Soireibyi, King. 17. Full-grown condition of
the loop. 18, 19. Young form, showing one of the early stages of the development of the loop.

Figs. 20-21a. Terebratella lupinus, Philippi, sp. Probably a young stage of Terebratella dorsata, with
Ma^ase//a-shaped loop. Magellan Straits; type in Berlin Museum (no. 7979).

Plate XV.

Figs. 1-8 «. Terebratella frontalis, Middendorff, sp. 1-2 6. Dredged by W. Dall at Atka Island ofi" the
Aleutian Chain, Alaska ; 2. A large example. 3, 4, 5, .T «. Dredged by Capt. St. John, off East
Yeso, North Japan. G. Interior of the dorsal valve to show the loop. 7. Interior of same
valve, with the loop removed to show the occlusor muscular scars. All in the Davidson
Collection, Geol. Dcpt., British Museum. 8, 8 «. Shell-structure after Middendorff.

Figs. 9-12. Terebratella Blanfordi, Dunker, sp. 9 and 11. Types after Duuker, from Wakayama,
Japan. 10. A specimen from the same locality (Davidson Collection, Geol. Dept., British
Museum). 12. Interior of the dorsal valve to show the loop.

Figs. 13-14. Terebratella Maria, A. Adams. Dredged by A. Adams at Satanomosaki, Japan.
13. Natural size. 14. Interior seen in profile to show the loop (Davidson Collection, Geol.
Dept., British Museum).

Figs. 15-29. Terebratella rubicunda, Sowerby. Faveau and Cook's Straits, New Zealand. 15—24. A
variety of forms and ages in the Davidson Collection, Geol. Dept., British Museum, 22, 23.
Modifications of the loop. 24. Adult condition of loop. 25. Vertical section of the ventral
valve near the extremity, considerably enlarged, so as to show the ordinary trumpet-like form
of the vertical passages, and the remarkable contraction which they exhibit in the inner aud
(probably) later formed layer; magnified 100 diameters (after Carpenter). 26. Another portion
considerably enlarged, showing the occasional bifurcation of the vertical passages ; magnified
100 diameters (after Carpenter). 27 a, 27 b. Young T. inconspicua, Sowerby, from his figures
in the Thes. Conch, pi. xxxi. figs. 102, 103, 104. 28, 29. Terebratella rubicunda, Sowerby, sp. ;
young elongated form from Chatham Islands, S. of New Zealand.

I)K. T. DAVIDSON ON liECENT BRACHIOPODA. 177

Plate XVI.

Figs. 1-5. Tvrthratdia tipitzbt'rgeiisis, Davidson. 1, la, b, c. Type dredged by 'I'orrell ueiir Spitzbcrgcu
(Davidson Collection, Geol. Dcpt., British Museum). 2, 2 n. From ofT Satanomosaki, Japan
(Adams). 3, 3 a. From the Gulf of St. Lawrenec (J. F. Wliiteaves). 1, 5. Interior of dorsal
valve enlarged to show the loop.

Figs. 6-9. Terebrutclla (ransversa, Sowerby, sp. ; figs, (j, 6 a, the ty])c alter Sowerhy. 7, 8, 9. Specimens
from off Vancouver Island 9. Interior of dorsal valve to show the loop. (Davidson Col-
lection, Geol. Dept., British Museum.)

Figs. 10-12. Terehrdtella transversa, var. canriiia, Gould. From oil" Sitka and Vancouver Island. 12.
Interior of the dorsal valve to show the loop (Davidson {Collection, Geol. Dept., British Museum).

F'igs. 13, 11«. Terebratella transversa, var. occidentulis, Dall. Coast of California. 13. Dall's figured
specimen. 14. From the Davidson Collection, Geol. Dept., British Museum.

Fig. 15. Terebratella ? pulvinuta, Gould. Puget Sound, Oregon. After (iould ; type in Washington
Museum, D.C., U.S.A.

Figs. 16-17/;. Terebratella? Frielii, Davidson. 16, 1(5 f/. Dredged by the 'Challenger' Expedition
off Halifax, in 1310 fathoms, \7-\7b. F'rom the Philippine Islands, opposite coast of the island
of Manilla, in 82 to 102 fathoms, ' Challenger ' Expedition. Specimens in the Zool. Dept.,
British Museum.

Figs. 18,18a. Magasella't labradorensis, Sowerby. After Sowerby's fig. Thcs. Conch, pi. Ixxi. tigs.
89, 90. Labrador. (Genus and species very uucertain.)

Fig. 19. Terebratella ? rubiginosa, Dall, sp. From the type in the Smithsonian Cabinet, Wasliington,
D.C. Locality uucertain.

Plate XVII.

Figs. 1-5. Magasella flexuosa, P. King, sp. 1,2. Exterior of valves dredged by the 'Challenger' Expe-
dition in the Gulf of Patagonia. 3,4. Interior of dorsal valve, to show the loop. 5. Profile of
another specimen, to show the enormously developed mesial septum.

Figs. 6-8 a. Magasella flexuosa? This is the type of the Terebratula rhombea, Philippi, from ^Magellan
Strait. In the Berlin Museum. I am indebted for these drawings to the liberality of Prof.
E. von jNIartens.

F'igs. 9-11. Magasella crenulata, Sowerby, sp., from Santa Cruz, Canaries. 9, 9rt. A specimen dredged
by H.Cuming (in the Zool. Dept., British Museum). 10, 10a, 10 /v. After Sowerby's figs, in
Thes. Conch, pi. Ixxi. figs. 96-98. 11. From a fig. in Reeve's Conch. Icon. Monogr. of Tere-
bratula, pi. viii. fig. 32.

I'igs. 12-13 a. Magasella patagomca, Gould, sp. 12. Gould's original type from United States Expedition
to Patagonia ; National Collection, Washington, D.C. 13, 13 a. Another specimen from the
same locality and collection given to me by Mr. Dall.

Figs. 14-15. Magasella snffusa, L. Reeve, sp. 14—14 6. The type, given to me by Mr. Reeve in
1860. 15. Interior of the dorsal valve of the same specimen to show the loop and the largely
developed septum.

Figs. 16-17 6. Magasella aleutica. 16. Type in the Washington Museum; from Unalaska. 17, 17a.
Another specimen given to me by Mr. Dall, from Popoff Strait, Shumagin Island. 17 b.
Enlarged.

Figs. 18-19. Magasella Adamsi, Davidson. Type specimen; from off the Island of Kuro-puua, Japan.
19. Interior of the dorsal valve to show the small loop.

Figs. 20-22. Magasella Gouldi, Dall. Hakodadi, Japan ; type in the National Collection, Washington,
D.C. 21, 22. Loop.

Figs. 23-32. Magasella Cwningi, Davidson, sp. 23, 24. Two living specimens of a liglit pink colour ;
dredged by Mr. J. Brazier at South Reef, Port Jackson Heads, S. Australia. 25, 26, 27. From

178 DR. T. DAVIDSON ON EECENT BRACK lOPODA.

Pigs Rock, South Australia. 28. Interior of ventral valve. 29. Interior of dorsal valve, show-
ing the loop. .30,31. Interior of Ijoth valves, nuich enlarged. 32. Loop of a young specimen.
Figs. 33, 33 a. Mar/asella fibula, Reeve, sp. From the type in the Zool. Dept. of the British Museum ;
said to have been dredged in Bass Strait, South Australia; probably a large example of
Magasella Cumingl.

Plate XVIII.

Fig. 1. Magasella (?) radiata, Dall. Popoff's Strait, north-west of Alaska. Ball's type, in the
National Collection, Washington, D.C. This enlarged drawiug was sent to me by Mr. Dall.

Figs. 2-3 a. Magasella (?) incerta, Davidson. 2. Exterior of the shell. 3, 3 a. Interior of dorsal valve,
enlarged. Dredged by the 'Challenger' Exjjedition west of St. Thomas, Danish West Indies.
In the Zool. Dept., Bi-itish Museum.

Fig. 4. Magasella (f) l(evrs,T)a\\. From Orange Harbour, Patagonia. Smithsonian Museum, Washington,
D.C.

Figs. 5, 5 a. Magasella (?) Malvinm, d'Orhiguy. After figs, in Voyage Amer. Mer. vol. v. pi. 85.
figs. 27-29. Malvines.

Figs. 6-9. Larjueus raliforniciis, Koch, sp. 6. A very large example (Davidson Collection, Geol. Dept.,
British Museum) . 7. A specimen in the National Collection, Washington, D.C. 8, 8«. In-
terior of dorsal valve, showing the loop. 9. Kiister's fig. of his T. Kochii, Chemn. Couch. -Cab.
vol. vii. tal). 2 «. fig. 9. All from off the Calif ornian coast.

Figs. 10-13 6. Laqiieus califormcus, var. vancouvericHsis. A series of specimens of different forms and
ages. Oft' Vancouver Island. 12. Interior of dorsal valve. (Davidson Collection, Geol. Dept.,
British Museum).

Figs. 14-18. Laqueus pictus, Chemnitz, sp. A seiies of specimens of different ages from Japanese waters.
14, 15, 17, 18. (Davidson Collection, Geol. Dept., British Museum.) 18. Interior of dorsal
valve, showing the loop. 10. Specimen figured by L. lleeve (Mus. de Burgh).

Plate XIX.

Figs. 1-5. Laqveus rubellus, Sowerby, sp. From Japanese waters. 1, 2, and 5. Large examples
(Davidson Collection, Geol. Dept., British Museum). 3-3 6. In Zool. Dept. of the British
Museum. 4, 4 a. Sowcrby's figured type.

Figs. 6-7 6. Laqueus siiffustis, Dall. From the Wharf at Yokohama, Japan. 6. Type in Smithsonian
Cabinet, Washington, D.C. 7-7 b. Davidson Collection, Geol. Dept., British Museum. This
is the shell which was erroneously referred by Adams to T. cranium.

Figs. 8-10 a. Megerlia Jeffreysi, Dall, = young of Laqueus californicus. From Port Etches, Alaska
Territory. Types in the National Museum, Washington, D.C. 10,10 a. Interior of the dorsal
valve, much enlarged.

Figs. 11-20. Megerlia truncata, hinne, sp. 11-14. Diflcrent forms and ages. 11-116. OiJ Teneriff"e,
dredged by the ' Challenger' Expedition. 12, 13, 14. Mediterranean forms, all in the Davidson
Collection, Geol. Dept., British Museum. 15, IG. Interior of the dorsal valve of Megerlia
truncata, showing loop. 17. Interior of the same valve to show the labial appendages.
18. Interior of the ventral valve of Megerlia truncata, after E. Deslougchamps, showing the
entire mantle ; vc, visceral cavity ; ap., calcified portion of the mantle forming the antei-ior
wall of the visceral cavity ; sv., calcified portion of the mantle on the course or direction
of the large sinus ; R, branch and smaller branches or subdivisions of the sinus on which the
brachial apparatus does not extend, enlarged four diameters.
Fig. 19. Interior of the dorsal valve of Megerlia truncata, also after Deslougchamps, showing the
complete mantle (the right branch of the brachial apparatus or loop has been removed in
order to show better the bearing of the diflerent portions of the pallial apparatus) ; cv., visceral

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 179

cavity; «/>, bracliial ap[)aratiis ; c, shield ; f/y;, raised portion ot the mantle forming the wall

of the visceral cavity; *(;/, lateral vein sinus; svm, median vein sinus.
Fig. 20. Portion of tlie internal surface of the shell of the same species, showing the usual imbricated

arrangement and the internal orifices of the vertical perforations : magnified 100 diameters

(after Carpenter).
Figs. 21-22. Mer/erlia truncata, var. monstmosa, Seacclii. 22. Enlarged. From the Mediterranean.

(Davidson Collection, Geol. Dept., British jSIuseum.)
Figs. 23-2f). Met/erlia? WUkmoesi, Davidson. From Twofold Bay, South Australia; 'Challenger'

Expedition (in the Zool. Dept., British Museum). 26. Interior of the dorsal valve.

Plate XX.

Figs. 1-8. Megcrlia sanyumea, Chemnitz, sp. 1, 2. From Honolulu, Sandwich Islands (Davidson Col-
lection, (Jeol. Dept., British Museum). 4—8. Different modifications in the loop according to
age (after E. Ueslongchamps). 4. Simplest stage. 5. Second stage. 0. A third stage.
7. Full-grown condition: be, running section of loop ; e, peripheral section ; i, median section;
p, point of attachment of recurrent lamelliB ; a, supplementary lamella. 8. Adult in profile.

Figs. 9-11. Megerlia pulchvUa, Sowerby, sp. After figures in Tlies. Conch. ])1. lx\i. figs. lOfj-lOr.
Probably a variation oi Megerlia sanguineal 11. Megerlia sanguinea, \;ir. jj/ilchella, Sowerby,
adhering to fucus. Dredged by Mr. John Brazier from the Bottle aiul Glass Bocks, Port
Jackson. 10-10 6. From ofl:' Shark's Point, Port Jackson, N. S. W. (Davidson Collection,
Geol. Dept., British ^luseuni.)

Figs. 12-12 6. Mrgerlia Reevei, T>a\'Khon, = Ts}ncnia Reevei, Adams. From Gotto, Japan. Probably a
bleached form of Megcrlia sanguinea.

Figs. 13-18. Bonchardia rosea, Mawe, sp. From Rio de Janeiro, Brazil. 13-14. Exterior of shell.
15. Profile view of interior of shell. 1(5. Interior of ventral valve. 17. Interior of dorsal
valve. 18. Profile ^'iew of dorsal valve. (Davidson Collection, Geol. Dept., British Museum.)

Figs. 19-23. Kraussina rwAm, Pallas, sp. 19-20. From South Africa. 21-22. Ijitcrior of dorsal valve
to show forked process. 23. Interior of same valve to show the small labial appendages. (All
in the Davidson Collection, Geol. Dept., British Museum.)

Figs. 2 1—20. Kraussina cognata, Sowerby, sp. 24. After Sowerby's fig. in the Thcs. Conch, pi. Ixviii.
figs. 12, 13; from South Africa (Zool. Dept. British Museum). 25. After Keeve's fig. Couch.
Icon., Monogr. of Terebralula, pl. ix. fig. 38". 26. Interior of dorsal valve.

Figs. 27-30. Kraussina cognata'^ A series of specimens dredged near the Cape of Good Hope. 29.
Interior of ventral valve. 30. Interior of dorsal valve. (All in the Davidson Collection, Geol.
Dept., British Jluseum.)

Figs. 31, 31 ff, /;. Kraussina BeshaijesijlDavidsou. Off Cape of Good Hope. (In the Davidson Collec-
tion, Geol. Dept., British Museum.)

Plate XXI.

Figs. 1-4. Kraussina jnsum, Lamarck, sp. Specimens dredged by the 'Challenger' Expedition off the

Cape of Good Hope. 2. In Zool. Dept., British Museum. 4. Interior of dorsal valve. 1 & 3.

In Davidson Collection, Geol. Dept., British Museum.
Figs. 5, 6. Kraussina Atkinsoni, T.-Woods. From Long Bay, South Tasmania (Davidson Collection,

Geol. Dept., British Museum). (!. Interior of dorsal valve.
Figs. 7-11. Kraussina {Megerlina) Lamarckiana, Da\idson. From Sydney Harbour, New South Wales

(Davidson Collection, Geol. Dept., British Museum). 11. Interior of dorsal valve of the same

species.
Figs. 12-14. Kraussina [Mega-Una) Davidsoni, Velain. From the shores of the Volcanic Island of

St. Paul. Collected by M. Velain in 1874 (Davidson Collection, Geol. Dept., British

Museum). 14. Interior of the dorsal valve, enlarged.
SECOND SERIES. — ZOOLOGY, VOL IV. 24

180 DR. T. DAVIDSON ON KECENT BRACHIOPODA,

Figs. 15-19. Plati/dia anomtoides, Scacclii, sp. 15. Specimen dredged by E. Forbes in tlic ^'Egean Sea.

IG. Dredged by the ' Challenger' Expedition off Marion Island (Zool. Dept., British Museum).

17. Dredged by W. S. Kent off Setubal, coast of Portugal^ near the Tagus (Davidson Collection,

Geol. Dept., British Museum). 18. Interior o£ dorsal valve. 19. Interior of dorsal valve,

enlarged to show labial appendages (after E. Deslongchamps) .
Figs. 20-22. Terebratula seminultun, Philippi (a synonym of Platydia anomioides). From the

Mediterranean. After Philippi's figures.
Figs. 23-27. Plutijdia Davidsoni, E. Deslongchamps, sp. From the Mediterranean. 23. Type.

23 a, b. Enlarged. 24. Spiny surface of ventral valve, much enlarged. 25. Fragment to

show the foramen. 2G, 27. Interior of dorsal valve (after drawings by E. Deslongchamps).

(Davidson Collection, Geol. Dept., British Museum.)
Figs. 28, 29. Gmi/n'ui capsu/a, Gwyn Jeffreys, sp. Specimen, much enlarged, from Belfast Bay (Davidson

Collection, Geol. Dept., British Museum). 29. A very young shell, much enlarged (after Gwyn

Jeffreys).
Figs. 30-35. Argwpe decollata, Chemnitz, sp. From the Mediterranean. 30. Natural size (Davidson

Collection, Geol. Dept., British Museum). 31. Dredged by the 'Challenger'' Expedition off

Gomera, Tenerifte (in the Zool. Dept., British jNIuseum). 32. A very young shell dredged at

Cape Breton (Marquis de Folin's Collection) . 33. Interior of dorsal valve, enlarged. 34 a.

Interior of ventral valve, much enlarged (after E. Deslongchamps). 35. Interior of dorsal valve,

much enlarged, showing the labial appendages.

Plate XXII.

Figs. 1-4. Cistella cistellula, Searles Wood, sp. 1. Natural size. 1 a, b. The same, enlarged ; from off
Shetland Island. 3. Interior of dorsal valve; enlarged. (1,3. Davidson Collection, Geol.
Dept., British Museum.) 2. A young specimen, enlarged (after Gwyn Jeffreys) . 4. Interior of
both valves of the same species, showing the powerful muscles on the ventral valve and the
labial appendages on the dorsal one.

Figs. 5, 6. Cislc'l/a? //««/b'fl, Philippi, sp. 5-5 c. Figures after Philippi. 6. A perfect specimen, enlarged,
from the Mediterranean ; sent to me by the Marquis of Monterosato.

Figs. 7-7 c. Cistella Woodwardiana, Davidson, sp. 7. Natural size; dredged by Lucas Barrett on the
N.E. coast of Jamaica (from the tj'pe, in the Cambridge Museum). 7 a, b, c, enlarged.

Figs. 8-24. Cistella neapolitana, Scaechi, sp. 8, 9, 10. Three examples from the Mediterranean
(Davidson Collection, Geol. Dept., British Museum). 11. Interior of dorsal valve. 12. Interior
of ventral valve. 13-24. After A. E. Shi^jley : — 13. Ovum. 14. Ovum with two segments.
15. Ovum with three segments. 16. Gastrula. 17. Larva with two segments, showing the stalk
attaching it to the walls of the brood-pouch. 18. Larva showing traces of three segments,
with eyespot c and commencing bristles : the outline of the alimentary canal is seen faintly.
19. Slightly older larva. 20. Larva with two kinds of cilia on the first segment: the second
segment has already begun to grow down over the third, which has constricted slightly into two
parts. 21. Free-swimming larva seen from the ventral side. 22. Free-swimming larva seen
laterally. 23. Young Argiope, the lophophore still circular, with twelve tentacles : the liver is
growing out as two lateral diverticula of the stomach. 24. View of the ventral shell of the same.

Figs. 25, 25 a. Chlella bipUcutu,'^c<^\\e\viA, sp. (probably Cistella neapulitana). From off' ]\Iessina. (Type
from Segucnza's Collection.)

Figs. 26, 27. Cistella Kowalevskii, Schulgin, sp. After Schulgin's figures. Enlarged. On Posidunia
off Sardinia. 27. Shell-structure. (Schulgin's Collection.)

Fig. 28. Cistella (jlubulijorinis, Schulgin, sp. ; after his figure. On stones off Sardinia. (Schulgin's
(Collection.)

Fig. 29. C«/e//a? iJarroisi, Schulgin, sp. ; after his figure. On stones at Villafranca; much enlarged.
(Schulgin's Collection.)

Figs. 30-34. Cistella cuneata, Risso, sp. 30-31 b. Exterior of two examples from the Mediterranean
(Davidson Collection, Geol. Dept., British Museum). 32. Interior of dorsal valve. 33. Interior

DE. T. DAVIDSON ON EECENT BRACHIOPODA. ISl

of veiitial valve. 3i. Interior of both valves, showiuj;- the muscles and labial appendages ;
from a specimen dredged by K. Forbes iii the Mediterranean.
Figs. 35—36. Cistella Barrettiana, Davidson, sp. 35. Exterior of shell of natural size. 35 a. Enlarged.
3fi. Interior of dorsal valve, enlarged. Dredged by Lucas liarrctt on the N.E. coast of
Jamaica. (In the Cambridge ^luseum.)

Plate XXIII.

Figs. 1, 2. Cistella Barrettiana, Davidson, sp. This is the type of Dali's Cistella rubrutiiicta, from Tortugas
(National ^Museum, Washington, D.C.). I a. Enlarged. 2. Longitudinal section, to show the
large submarginal septum on the dorsal valve.

Figs. 3, -i. Cistella Schruiiiini, Crosse, sp. 3. After Crosse's figures, enlarged. 4 is an enlarged drawiri"
of fig. 3 6.

Figs. 5, 6. Cistella Ititea, Dall. 5 a. Enlarged. 6. Longitudinal view of the dorsal valve, to show the
elevated grooved submarginal septum. From Tortugas. (National Museum, Washington, D.C.)

Figs, r, 8«. CistelU aittillarum, CvQssCjSi^. 7. After Crosse. 8«. Drawn by myself and cular"ed, alter
Crosse's figure. From Guadeloupe. (Crosse's Collection.)

iMgs. 9-11. Theeidiuiii Barretli, S. P. Woodward, sp. Dredged by Lucas Barrett, north-east coast of
Jamaica. 9. E.xterior of shell. 9 a. Enlarged. 10. Interior of ventral valve, enlarged. 11,
Interior of dorsal valve, enlarged. (In the Cambridge Museum).

Figs. 12-22. Thecidiu?nmediierraneum,li\>iso,sp. 12. Natui'al size. 12 a, 0. Enlarged. 13. Shell with
both valves open. 14. Interior of ventral valve much enhu-ged, after E. Deslongchamps, showin"-
the pailial apparatus in its integrity, of which only a small portion has been removed to show
the cavity wherein are lodged the sinuses and the organs of reproduction. 15. Interior of ventral
valve of Thecidium mediterraneum, to show the position of the ventral adjuster muscles (a)
of the small concave plates, " coques " [h) of Lacaze-Duthiers, to which the extremities of the
adductor muscles (Hancock's occlusors) are attached ; and the oval scars (c) left by the divaricator
muscles of Ilani-ock (the " muscles abducteiirs " of Lacaze-Duthiers). 16. Interior of dorsal
valve, much enlarged : a, c, e,f, and y, ascending process ; h, bridge-shaped process ; i, k, half-
crescent or descending process; m, cardinal jjrocess; w, .scar formed by Hancock's adjustor
muscles ( = the ''muscles adducteurs lateraux on externes " of Lacaze-Duthiers). 17. Interior
of dorsal valve (after Lacaze-Duthiers), to show the labial appendages, much enlarged.
18. The Icast-advanecd embryo hitherto examined; it resembles an agglomeration of small
cells. 19. Two embryos, a little more developed and suspended from cirri. 20. An embryo
with four lobes. 21. An embryo still more developed, enlarged. 22. Median portion of a
galling fenude Thceidium, showing the embryo-pouch partly broken, and the posterior median
ciri'i at the nioulli, cacli bearing a bundle of embryos. (Figs. 17-22 after Lacaze-Duthiers.)

Plate XX iV.

Figs. 1-11. li/iyiirhonella psiftacea, GmvYni, sp. 1. A large example dredged by McAiidrcw and Barrett
in Norwegian seas. 2. Dredged near Baffin's Bay by Gwyn Jeffreys during the 'Valorous'
Arctic lOxpedition, 1875. 3. Dredged by Capt. Naresat Franklin Pierce Bay, 1875, lat. 70" 25'
N., in 15 fathoms. 4, 5. Young specimens from Sitka, dredged by Dall. (All in the Davidson
Collection, Geol. Dept., British Museum.) 6. Interior of dorsal valve. 7. Interior of ventral
valve. 8. Profile view of same.

Fig. 9. General side view of the viscera of Rhynchonella psiltacea, after Hancock's figure (Phil.
Trans, vol. cxlviii, pi. Ixi. fig. 2, 1858) : — "a, anterior wall of perivisceral chamber; bb, brachial
organs ; e, ventral terminations of occlusor muscles ; c* t*, dorsal terminations of anterioi' and
posterior occlusors ; r/(/, divaricators, the left one cut through; r/*, ventral « all of perivisceral
chamber; e, ])cduiicle; e*, capsule of ditto; /, peduncular muscle; ff, one of the dorsal
adjusters; h, one of the ventral ditto; i, oesophagus; J, stomach, exhibiting the two openings
of the left hepatic ducts, the liver having been removed from this side ; k, right lobes of the
liver; k*, posterior lobe; /i**, anterior ditto; /, dorsal mesenteric membrane; ///;/(, ventral ditto;

182 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

n, lateral gastro-parietal band ; o, centi'al ditto ; pp, ilio-parietal bands ; q, heart ; ?•, brancbio-
systemic vein ; s, aorta ; tt, dorsal and ventral, pallial or genital arteries ; n, right ventral
oviduct; !<*, portion of left ditto cut through, v, oesophageal ganglia; w, sheath of crural
process or oral lamina; x, orifice leading into ditto; y, portion of ditto of the opposite side;
z, terminal sac of the left great brachial canal ; z*, ditto of the right or opposite arm, seen
through the mesenteric membrane."

Kg. 10. Portion of shell of Rhynchonella psittacea (after Carpenter), showing at aa the internal surface,
with the imbricated arrangement of the extremities of the component prisms, and at b the
aspect of the prismatic substance, as displayed by a fracture nearly in the dii'cction of the
length of the prisms, showing also the entire absence of the least trace of perforations ; mag-
nified 100 diameters. 11. Portion of the shell-sui-face of the same (after Carpenter), more
highly magnified, showing the imbricated arrangement and the entire absence of perforations.

Figs. 12-13 c. Rhynchonella psittacea, var. Woodivardi, A. Adams. From Japanese waters. (Both in
the Davidson Collection, Geol. Dept., British Museum.)

Figs. 14-15 b. Rhynchonella lucida, Gould. From Japanese waters (Davidson Collection, Geol. Dept.,
British Museum). 15, 15 a, 15 6 enlarged.

Figs. 16-19. Rhynchonella nigricans, Sowerby. A series of specimens from Faveau Strait, New Zealand.
(Davidson Collection, Geol. Dept., British Museum.)

Fig. 20. Rhynchonella nigricans, var. pyxidata, Boog Watson. From off Kerguelen Island, ' Challenger '
Expedition. (Zool. Dept., British Museum.)

Plate XXV.

Figs. 1, 1 c. R/njiichonella Grayi, S. P. Woodward. 1 c. Enlarged. Habitat not quite certain.
(Zool. Dept., British Museum.)

Figs. 2-4. Rhynchonella cornea, Fischer, MS. Dredged off Cape St. Vincent, 'Talisman' Expedition
(Mus(3um d'Histoire Naturelle, Paris). 3. Obtained by Dr. Gwyn Jefl'reys, chops of the English
channel (Dr. Gwyn Jeffreys's Collection, now in Boston Museum, U. S. A.). 4. Portion of the
interior of the dorsal valve, enlarged, to show the hinge-plate, curved lamellie, and muscular
interior impressions.

Fig. 5. Rhynchonella sicula, Seguenza. Fossil in the Pliocene limestone of Messina, and supposed by
Dr. Gwyn Jcfireys to occur in the recent condition.

Figs. G-13. Atretia gnomon, Gwyn Jeffreys. 6, 7. Natural size. 7, 8 a. Enlarged. Dredged by Dr.
Gwyn Jefl'reys during the Norwegian Arctic Expedition, about thirty miles west of Tromso, on
slopes of the banks. 9. Dredged by Herman Friele off the coast of Finmarken, about thirty
miles west of Tromso. 10. Interior of the dorsal valve of a specimen dredged by the ' Talisman '
Expedition off Morocco (Marquis de Folin's Collection). 10 a. Showing the largely
developed mesial septum. 11 and 13. The dorsal valve, from specimens dredged by Dr. Gwyn
Jeffreys. 12. Fragment of the interior of the ventral valve, to show the developed dental plates.

Figs. 14, 15. Rhynchonella Dciderleini, Davidson, ]\IS. From Sagami Bay, Japan. In the collection of
Dr. Doderlein.

Figs. 16-17 a. Atretia Brazieri, Davidson, MS. Dredged by Mr. John Brazier ofl^ Port Stephens, New
South Wales. 17. Intei'ior of dorsal valve. (Davidson Collection, Geol. Dept., British Museum.)

Tretenterata.

Figs. 18-23. Discina striata, Schumacher, sp. 18. A typical specimen, after Sowerby. 19,19 a. A
malformation. 20, 20 a. An enormously thickened upper valve. 21. Interior of the same
valve, luuch enlarged (Davidson Collection, Geol. Dept., British Museum). 22, 22b. Type of
Discina Evansi, Davidson; from Bodegas (Cuming Collection, Zool. Dept., British Museum).
23, 24. Type of Gould's Crania radiosa, from Cape Palmas (National Museum, Washington,
D.C.). 25. Exterior of the upper valve, much enlarged. 25. Exterior of the lower or foraminated
valve. 24. Interior of the same valve, much enlarged. 26. Section of the valve, to show
the position of the foramen.

[ 183 ]

III. A Monograph of Recent Brachlopoda. — Part III.
By TuoMAS Davidson, LL.D., F.B.S., F.L.S., F.G.S., c^-c.

Head ITth June, 1SS6.

(Plates XXVI.-XXX.)

LYOPOMATA, Owen^TRETENTERATA, King.

Family CRANIID.E.

Genus CRANIA, Retzius, 1781.

In the recent condition this family is represented hj the genus Crania only, of which the
following four or five sjjecies have heen determined * : —

1. Crania anomala, Miiller, sp., 177G. I 4. Crania Suessii, Reeve, 1862.

2. Poi«'/a/t's«', Dall. (Uiicertain sj).) 5. ^Vz/jo/i/cff, Adams, 1863.

3. turhbiata, Poll, sp., 1795. I

In an interesting revision of this family, published by Mr. AV. H. Dall in the ' Bulletin
of the Museum of Comparative Zoology,' vol. iii. 1871, the author seems disposed to
regard Crania turhinata as a variety of the northern C. anomala. Some uncertainty also
prevails with respect to the Crania Pourtalesii, Dall, 1871, which the author says may
possibly be a strongly marked variety of C. anomala,

101. Crania anomala, Miiller, sp. (Plate XXVII. figs. 1-9 Z-.)

Patella anomala, Miiller, Prodr. Zool. Dan. p. 237, 1776; Zool. Dau. i. p. i, tab. 5. figs. 1-8, 1788;
Gmelin, Linn. Syst. Nat. cd. xiii. p. 3721. no. 151, 1788.

Orbicula anomala, Cuvier, Tab. Elein. de I'llist. Nat. p. 435, 1799; Regnc Animal, ii. p. 501, 1817.

Patella distorta, ^loutagu, Traus. Liua. Soc. vol. xi. p. 195, pi. xiii. fig. 5, 1808.

Orbicula norvegica, Lamarck, Syst. p. 140, 1801 (not Sowerby) ; An. sans Vert. vol. vi. p. 242, 1819.

Anomia turbinuta, Dillwyn, Descrip. Cat. Recent Shells, vol. i. ]). 285, 1817 (not Poll).

Orbicula norvegica, Schumacher, Essai d'uu Nouv. Syst. Ilab. Vers Test. p. 176, pi. xxi. fig. 2, 1817.

Crania per sonata (part.), Defranee, Diet. Sci. Nat. xi. p. 312, 1818.

Discina ostreoides, Tnrtou, Conchol. Diet. Brit. Islands, p. 238, 1819 (not Lamarck).

Crania personata, Sowerby (part.), On the Genera of Orbicularia and CVawia of Lamarek, Trans. Linn.
Soc. vol. xiii. pi. 26. fig. 3 a (not 3 c), 1822.

Criopus anomalus, Fleming, Phil. Zool. ii. p. 499, 1822 ; and Prit. Animals, p. 377, 1828.

Orbicula norvegica, Anton, Verzeich. der Conehylien, p. 21, 1839.

Orbicula norvegica, Deshayes, Eneycl. 'Mith. iii. p. 668, 1832 (partly, + turhinata, Poli) ; Poticz et
Michaud, Galerie des Mollusques du Musee de Douai, vol. ii. pi. 43. fig. 1 ?, 18 IL

* A single dead valve of a small Crania, too imperfect to vrarnuit specific identification, was dredged by H.5[.S.
' Clialleuger ' at Station 33, off Bermuda, at a depth of 435 fathoms. Sea-bottom, mud. ^Report on the Erachiopoda,
Yoyage of H.il.S. 'Challenger,' Zool., vol. i. p. 05.)

SECOND SERIES. — ZOOLOGY, VOL. IV. 25

184 DE. T. DAVIDSON OX EECENT BEACHIOPODA.

Crania anomala, Loven, Index Moll. Scand. p. 29, 1846.

Crania noiiwgica, Sowerby, Thes. Conch, i. p. 3G8, pi. 73. figs. 15-17, 1847.

Criopus orcadensis, Leach, Moll. Great Brit. p. 358, pi. xiii. figs. 6-8, 1852.

Crania anomala, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 376, 1852; Brit. Foss. Brach.
Introdnction to vol. iii. p. 123, figs. 44—16, 1853 ; and Mem. See. Linn. Normandie, vol. x. pi. 13.
figs. 14-36, 1856; Forbes and Hanley, Brit. Moll. ii. p. 366, pi. Ixi. figs. 7 & 8, 1853.

Crania norvegica, Carpenter, in Davidson, Br. Foss. Brach. Intr. to vol. i., 1853.

Crania anomala, L. Barrett, Ann. & Mag. Nat. Hist. 2nd ser. vol. xvi. p. 259, 1855.

Crania turbinata. Woods, Index Test. ed. Hanley, pi. xi. fig. 2 (not Poli), 1856.

Crania a7iomala, S.P.Woodward, A Manual of Mollusea, pp. 235,236, figs. 157, 158, 1856; A,
Adams, The Genera of Recent Mollusea, p. 583, pi. cxxxii. fig. 3, 1858; E. Suess, Ueber die Wohnsitze
der Brachiopoden, Sitznngsb. k. Akad. Wissensch. Wien, Bd. xxxvii. p. 220, 1859 ; Chemnitz, Man. de
Conch, ii. p. 230. fig. 1178, 1862 ; L. Reeve, Conch. Icon., Monogr. of Crania, pi. 1. fig. 4, 1862; Gwyn
Jeffreys, Br. Conch, vol. ii. p. 24, 1863; and vol. v. pi. xix. fig. 6, 1869; W. King, Trans. Roy. Irish
Academy, vol. xxiv. 1869; Dall, Revision of the Craniidte and Discinidse, Bull. IMus. Comp. Zoiil. Har-
'vard, vol. iii. p. 32, 1871; and Proc. Acad. Nat. Sci. Philadelphia, p. 198, 1873; G. O. Sars, Moll.
Regionis Arcticte Norvegife, ^. 8, 1878.

Crania anomala, var. alba, Gwyn Jeffreys, Brit. Conch, vol. v. p. 165, 1869.

Shell hinc^eless, marginally rounded or somewhat squarely orbicular or suTiquad-
rate, with rounded angles ; generally wider than long ; posterior border straight or
slightly indented, shorter than the breadth of the shell, lateral and front margins
gently rounded outwards. Upper valve conical, flattened posteriorly and anteriorly
from the apex to the margin. Apex or vertex sometimes sharply hooked and pointed,
more or less subcentral or submarginal, surface wrinkled by concentric lines of growth.
Colour reddish chocolate-brown or pale or dark liver-colour. Lower valve attached
to and moulding itself xipon stones or shells by the whole of its exterior surfoce.
In the interior of the ventral or lower valve there exists a wide, flattened, granulated
border, sloping upwards and inwards from the margin of the shell with a sharp
inclination. At each angle of the posterior inner margin are situated two oblique,
widely separated, oval-shaped impressions, left (according to Hancock) by the divaricator
muscles ; and near the centre of the bottom of the valve are two contiguous, larger,
obliquely placed scars, due to the adductor muscles; between these last and a little higher
u]) are two other smaller impressions attributed to the dorsal adjustors. In the interior
of the upper or dorsal valve there exists a thin, sharp-edged, granulated margin all round
the valve, which fits closely to the sloping margin of the ventral valve and is inwardly
limited by a narrow convex ridge which surrounds the interior of the valve. At its
inner angles are two almost circular projecting scars, due, according to Hancock, to the
divaricator muscles, those scars being widely separated by a concave space ; under these
and lower down are two oval-shaped adductor muscular scars, widely separated by a
blunt, rounded ridge, wliich extends a little distance towards the front. On each side
of its anterior extremity are two small oval-shaped scars, referred by Hancock to the
brachial muscles. On the surface of the anterior half of the bottom of tlie valves are
seen digitate vascular impressions. The animal is of a white colour, tinged with yellow
and l)rown. Mantle very thin, extending to the edges of the valve and closely adhering.
Laln'al appendages free, thick, and fleshy, spiral at their extremities, directed towards the
concavity of the dorsal valve, and supported by a nose-like prominence in the middle of the

I

DE. T. DAVIDSON OX EECEXT BEACIIIOPODA. 185

lower or ventral valve. Cirri numerous, long an 1 stiff. On tlio under valve the ovaries
are of a tawuy hue, as figured by Miiller. Length 9 lines, l)readtli 11 lines.

Hah. Nortli Atlantic seaboard from Spitzbergen to Vigo Bay* ; in 18-90 fathoms on
almost every part of the Scotch and Irish coasts as well as in the seas of Shetland and the
Orkneys (J(>ffreys) ; Isle of Man (Forbes) ; Greenland. Prof. E. Forbes says, in liis
' History of British Mollusca,' tliat " this curious bivalve was first added to the British
lists by Dr. Fleming, who found it adhering to stones, from deep waters in Zetland ;
since then it has been taken abundantly in several localities, chiefly on the Avcst coast of
Scotland ; off Arran, in 20 fathoms (Smith) ; Loch Fyne in 30-80 fatlioms, plentiful on
stones; off ISIull in 20 to 90 fathoms; off Lismore in from 20 to ;50 fathoms; off
Armadale in 18 fathoms; off Copenhaw Head, Skyc, in 40 fathoms; on tlie Ling Bank
off Zetland in 50 fathoms (M'Andrcw and E. Forbes) ; Loch Alsh, Loch Carron, Ullapool,
East of Lerwick, in 40 fathoms (Jeffreys). In Ireland it has been taken off Youghal by
E. Ball, and off Cork by Humphreys."

Ohs. Specimens of C. anomala vary much in shape, whicli is to a great extent de-
pendent on tlie nature of the object to which they are attached. At times a number are
clustered together so closely on the same stone that they necessarily become distorted
during grow tli. The position of the vertex and the elevation of the upper valve vary
also a good deal, as well as the circular wrinkles that cover its surface. Interiorly the
muscular impressions also vary to some extent, and, as remarked by Dr. Gwyn Jeffreys,
"sometimes the shell is ribbed across or obliquely, having taken the impression of an
Astarte or Pecteu on which it has been moulded. Being often affixed to rugged stones
or small pebbles, its shape is adapted to the angles and extent of the basal surface.
"When it has bare standing-room only, it increases in height and becomes regularly conical.
The under valve of specimens attached to a smooth shell of a Pinna is usually a mere
film." To small bleached specimens dredged by Jeffreys and Barlee off Shetland in
170-530 fathoms, Dr. Gwyn Jeffreys in 1869 applied the varietal name of alha. Two
of these specimens were kindly forwarded for my examination by Dr. Jeffreys, but I could
not discover any valid grounds for separating them from Miiller's species. The lower
or attached valve is entirely concealed by the upper one. (See Plate XXVII. figs. 9-9 b.)

The intimate structure of the shell of Crania anomala lias been described by Dr.
Carpenter in chapter 2 of the Introduction to vol. i. of my ' Monograph on British
Fossil Brachiopoda,' and by Prof. "NV. King in his memoir " On the Histology of the
Test of the Class Palliobranchiata," in vol. xxiv. of the Trans, of the Ptoyal Irish
Academy. Dr. Carpenter sajs,_loc.cit. p. 37, that in Crania norvegica " the shell-structure
is widely different from that of Brachiopoda generally. Instead of a series of flattened
prisms arranged with great uniformity, Ave only meet with a substance which does not
present any regularity or distinctness in the arrangement of its components, but which
is not at all unlike that of which many Lamellibranchiate shells are composed, and may
probably, like it, be regarded as liaviug been originally formed of the coalescence of cells,
which were destitute of any consistency in size, shape, or general arrangement. But

* Specimens of Crania (C. anomala or C. turhinata"?) -were oLUiincd Lj- the ' rorciipinc ' Expedition in the
Mediterranean in from 207-2GG fathoms; in 1869 at Station 2 in 8t>S fathoms, and Station 12 in G70 fathoms; in
1S70 at Station 1 in ij(;7 fathoms, and at Station 3 in 600 fathoms (Jeffreys).

25*

186 DE. T. DAVIDSON OX RECENT BKACHIOPODA,

whilst departing from the general Brachiopodons type in this respect, the shell of Crania
is quite conformable to it, in being penetrated by canals which are prolonged from the
lining membrane of the shell, and which pass towards its external surface. These differ
from those of Terebratula, however, in not arriving at that surface, and in breaking up
into minute subdivisions as they approach it. They usually open near the internal
margin of the valves, by orifices so large as to be apparent to the naked eye, but nearer
the central part of the valves, their orifices are frequently so minute as not to be readily
discernible. Tliis is in consequence of the formation of an additional lamina within the
old one, and of the contraction of the canals in their passage through it."

Prof. King states that " Crania anomala agrees with the Ancylobrachs in having
both valves perpendicularly perforated ; but this character is not, as iu them, distinctly
manifested on the outer sui'face of the shell. In the upper valve, the perforations,
somewhat slender, are widest at their base, that is, where they open out on its inner
surface ; in other w^ords, their apertures, when observed with a high magnifying power,
are seen to be funnel-sliaj)ed, separated from one another by a tolerably well-defined,
ridge-like space ; but, with a low power, they simply appear to be separated by a space
approximately equalling their own diameter. The apertures occur on the whole of the
inner surface of this valve ; and they also occur on the corresponding surface of the

lower one Leaving the contracted portion of their funnel-shaped base, the

perforations pass upwards, with a slight attenuation, towards the opposite surface of the
valve ; but generally, on reaching the brown layer, they become divided, each one
sjilitting into three, four, or more widely diverging branches ; occasionally this takes
place before the perforations leave the white layer. The branches on approaching the
dark-coloured or epidermal portion of the external layer, become minutely subdivided
into from two to five branchlets, which appear like arborescent tufts. The branchlets,
belonging to the immediately adjacent perforations, become intermixed, causing the
intervening spaces, when viewed as a transparent object, to appear as if marked with
an irregular net-v/ork of very fine lines. It is difl&cult to determine whether the
branchlets terminate in the epidermal portion of the exterior layer. Both the branches
and branchlets are sub radially disposed ; an arrangement which is, however, much
disturbed near the margin of the valve owing to their tendency to this part.

" As regards the intimate structure of the flat or under valve, which is habitually fixed
by its entire surface to stones and other foreign objects, I am only imperfectly acquainted
with it ; all I can say is, the apertures of the perforations are widely funnel-shaped, and

less regularly disposed than those already noticed A vertical section, obtained

from a specimen of C. anomala, shows that the outward growth of its upper valve is occa-
sionally interrupted ; which is manifested by the continuity of the external brown layer
being here and there broken."

The animal of C. anomala seems to have been partially described and figured for the
first time in 1788 by Otto Frederic Miiller. He gave enlarged illustrations showing the
position and shape of the labial appendages, which extend horizontally, each forming a
plume-like curve, the fringe side being outermost. He likewise figured the vascular
impressions and some of the muscles. He styled the animal "Vermes singularissimus"
and while placing it in the genus Patella, admitted that on close inspection the shell

DR. T. DAVIDSON OX KECEXT BRACllIOPODA.

187

Fig. 20. A.

(lifTers entirely from tliat of a Limpet. Fuvtliermnre, as observed l)y Dr. Gwyn Jeffreys,
" his comparison of the branching- arrangement of the arms to the dusky horns of a wild
goat is not inappropriate."

In 1853 the animal of C. anomcilo was to some extent examined by Dr. S. P.
Woodward and myself, and in vol. i. of my ' British Fossil Brachiopoda,' and subsequently
in his ' Manual of the Mollusea,' we briefly noticed and figured the thick, fleshy, and
spirally coiled labial appendages, directed vertically to the cavity of the dorsal valve and
in this respect differing from those we found in Blscina lamellosa; we also observed
that the mantle-lobes extend to the edges of the valves and adhere closely, as in
Thecidium, their margins being plain and thin. Dr. Gwyn Jeffreys observes, at p. 26
of vol. ii. of his ' British Conchology,' that " the animal is by no means timid ;
when a camel-hair brush is thrust between the gaping
valves, thev immecHatelv close, but in a few seconds after
open again, and this teasing experiment can be repeated
many times without alarming the Crania or making it
sulky. The cirri are not contractile, and do not withdraw
or shrink when touched. Each arm has about sixty of
them. The fry are quite white and semitransparent,
and they have only a few tubular perforations. They
adhere in the same way as their jiavents."

Lucas Bari'ett, who had seen many specimens of C
anomala in life between Drontheim and Tromsoe attached
to stones and shells, in iO to 150 fathoms water, stated, in
the Annals and Mag. Nat. Hist, for 1855 (vol. xvi.), that the
cirri, but not the arms, are protruded beyond the margin
of the shell. The valves open by moving upon the straight
side as on a hinge without sliding the valves — conse-
quently no sliding-muscles were required. At my request
in 1859 Mr. A. Hancock examined the animal of C.
anomala, and in sending me the sketches here reproduced
he said " oc are undoubtedly the occlusor muscles, cU the
dlcaricators ; when the former relax, and the latter contract,
the fluid in the perivisceral chamber will be forced forward,
and then the valves will ha opened a little in front. The
action is the same as in Lingula ; va may be called the
ventral acljitsfors, they form a scar close to the outer
border of the divaricators in the ventral valve. The other
extremities of the muscles converge and pass rovmd the
outer margin of the occlusors to which they adhere ; but,
be adds, I could not determine exactly how they terminate.
I presume that the other extremities form, as stated, a scar
in the ventral valve of C. anomala from the fact of such a
scar existing in the fossil Crania ignahergensis. Both the
dorsal adjustors, da, and the ventral adjustors, va, are much

A. Dorsal surfece of an animal of
Crania anomala (after Hancock).

mm, mesenteric muscle ; dl. divari-
cators ; da, dorsal adjustors ; va,
ventral adjustors ; oc, occlusor :
Jjn, brachial muscles; ?<ji>, brachial
process.

B.

B. Ventral surface of animal of
Crania anomala (after Hancock).

mm, mesenteric muscle ; ac, ali-
mentary canal : di, divaricators ;
da. dorsal adjustors ; va, ventral
adjustors : oc, occlusor ; hm,
brachial muscles; h^, brachial
process.

188 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

torn in all the specimens ; but I tliink there can be little doubt that they are as represented
in the sketch — one end being attached to the dorsal valve close to the outer border of the
divaricators, the other most probably to the anterior process of the ventral valve; but I
could not satisfactorily determine this ; the fibres of this extremity, however, are firmly
united to the inner layer of the occlusors. The brachial muscle, bm, has both the
extremities attached to the same valve (the dorsal), the anterior end to the cardinal
process, the dorsal close to the outer margin of the occlusors, with which it blends its
fibres ; the arms are fixed to those muscles, which perhaps may be named brachial :
mm. is a flat thin membranous muscle binding the dorsal extremities, to which, according
to Woodward, the cardinal muscle is attached. The ovarian impressions have some
resemblance to the uniform scars in the Trodiiciklce, but they take their origin from
behind the occlusor muscles ; I have little doubt that they are ovarian, they can also,
I believe, be traced in both valves " *.

TJncertaisi Species.
102. Crania Pourtalesii, Ball. (Plate XXVII. figs. 12, 12 a.)

Crania Pourtak's'ii, Dall, Bull. Mus. Comp. Zool. Harvard, vol. iii. p. 35, 1871.

Dr. Dall states, loc. cit. p. 35, that " the few specimens of Crania dredged by the United
States Coast Survey Expedition (off the Sambos, Florida, in 116 fathoms, and off the
Sand Key in 105 fathoms f) offer some apparently constant differences from C. anomala.
They are somewhat distorted, very transverse, and have obscure indications of radiating
rugosities. The shells are smaller than C. anomala, have a strong concentric foliation
caused by the imbrication of the lines of growth. The colour is much the same as in
anomxila ; one white sjDccimen with a few radiating brown lines M'as dredged on a stone
in 126 fathoms, off Sand Key, by Mr. de Pourtales. The interior of the lower valve was
of a green colour. The posterior muscular impressions are smaller and closer together
than in C. anomala. It is very possible, however, a strongly marked variety of that
species ; but in case the collection of a larger number of specimens sliould prove its dis-
tinctness I would propose for it the name of C. JPoiirtalesii, Dall."

Obs. Never having seen this shell, I reproduce verbatim Dr. Dall's description of it.

10.3. Crania turbinata. Poll, sp. (Plate XXVII. figs. 14-23, Plate XXVIII. figs. 1, 1 a.)

Anoinia turbinata, Poli, Test, utriusque Sicilise, ii. p. 18'J, tab. 30. fig. 15, 1795 : Criopus fimbriatus
(animal), Criopoderma tnrhinatum (shell).
Pateltu kermes, Humplicy and Da Costa, Nat. Hist, of Shells, p. 7, pi. i. fig. 10, 1770.
Anomia cranioluris (part.), Gmelin, Liuu. S^st. Nat. ed. xiii. vol. iv. p. 3340, 1788.
Anomia turbinata (part.), Dillwyu, Cat. of lleceut Shells, p. 286, 1817.

Crania personata, J31aiuville, Diet. Sci. Nat. vol. xi. p. 312, pi. 304, fig. 2, Cat. xv. 1818 (uot Lamarck) .
Crania ringens, lloeuiughaus, Beitr. Mouogr. Crania, p. 3, fig. 2, 1828.
Crania rustruta, lloeuiughaus, Beitr. Mouogr. Crania, p. 3, fig. 3, 1828.

* [A series of remarkable observatious on the living animals of Crania and Discina were recorded by M. L. Joubin.
at the Arago zoological station, Banyuls-sur-iler, in the years 1884, 1885, and 1880. A brief abstract of his impor-
tant memoir, ' llecherches sur lAuatomie dcs lirachiojjodes luarticiiles,' is appended to this monograph. — A. C.j

t Crania rourtah-sii has also been dredged oft tSt. Vincent, West Indies, in 88 fathoms (DaU, Dull. Mus. Comp.
Zool. Harvard, vol. xii. p. 205, 1880).

DR. T. DAYIDSOX OX EECEXT BRACHIOPODA. 189

Orbicula turhinata, Dcsliayes, ed. Lamarckj An. sans Vert. vol. vii. ji. 317, 1836.

Crania rim/ens, .Vnton, Verz. der Conchylien, p. 2\, 1839; G. Sow. Thcs. Conch, i. p. 307, ])1. Ixxii.
figs. 10 & 11, 18 Ifi ; E. Forbes, Report ou the Mollusca of the ,Egeau Sea, Brit. Assoc, for the Advance-
ment of Science, 1843.

Crania ringens and C. roslrata, E. Suess, Ueber die "Wohnsitze der Brachiopoden, Sit^ungsb. k. Akad.
Wissensch. AVien, Bd. xxxvii. p. 2:23, 1859.

Crania rostrata, L. Reeve, Conch. Icon., Monogr. of Crania, pi. i. fig. 3, 1862.

Crania rinyens and C. rostrata, Goldfuss, Petrefaktenk. Deutschlands, p. 291, and p. 292, pi. cL^ii.
figs. 2 & 3, 1826-33; Brusina, Moll. Dalmati, Rcale Soc. Botanica di Vienna, vol. xvi., 1866.

Crania turhinata, L. Reeve, Conch. Icon., Monogr. of Crania, pi. i. fii;-. 1, 1802 ; II. C. A\'cinkaufiF, Die
Conch, des Mittclnieeres, p. 291, 1867.

Crania anomala, var. turhinata, Dall, Revision of the Craniidaj and Discinidic, Bull. AIus. Comp. ZoiJl.
Harvard, vol. iii. p. 34, 1871 ; and Proc. Acad. Nat. Sci. Philadelphia, p. 199, 1873.

Crania rostrata, L. Jouhin, Comptcs Reudus, t. xcix. p. 98j, 1884; t. c. p. 464, 1885; Arch, dc
Zool. Exper. t. iv. p. 161, 1886.

Shell marginally more or loss rounded, rather Avider than long, In'oadest anteriorly,
sliglitly indented at its posterior and anterior margins; lal)ial margins outwardly curved
and slightly pinched in close to the posterior margin. Upper valve more or less sub-
trapezoid, conical or limpet-like. Vertex central or suhmarginal, pointed or hooked,
curving towards the posterior margin, valve flattened from the apex to the posterior and
often anterior margins. Smaller or lower valve moulding itself to main objects by its
entire outward surface. Upper valve small or roughened. In the interior of the flat-
tened lower valve a Avide, thickened, sloping, granulated rim or border, thin at the edge,
surrounds the shell; it forms a slight inward curve posteriorly, then curves in just
under the posterior angles and again outwardly all round the anterior portion of the shell.
Each of the posterior angles of the inner margin is taken up by a projecting circular scar,
left by the divaricator muscle. These two scars are widely separated, and the intervening
space is occupied by two other small projecting eminences, which Hancock refers to
mesenteric muscles, destined probably to draw the alimentary tube backward. At the
anterior labial angles of the divaricator scars another smaller one is seen, AAhich has been
attributed by the same distinguished zoologist to the dorsal adjustors. Lower down
towards the middle of the bottom of tlie valve are two oblique, almost contiguous oval-
shaped scars, which have been referred to the adductor muscles, and between them and
more towards the posterior edge is seen a nose-like projection composed of two small
oblique oval-shaped scars, which have been referred to the anterior extremities of the
dorsal adjustors. The remaining anterior portion of the interior of the valve is traversed
by digitate vascular (?) impressions. In the interior of the upper valve a raised thick-
ened rim or border margins the interior of the shell and follows the ins and outs or
curves of the lower valve. At the inner angles are two oblique oval-shaped scars due to
the divaricator muscles, and in the space separating them are two other smaller scars,
perhaps due to the mesenteric muscles ; under these and lower down are two large
oblique projecting elevations caused by the adductors, these impressions being separated
from each other by a narrow hollow space, the remaining area between these and the rim
being taken up by digitate vascular (?) imjiressions. The shape and position of tlie
labial appendages have been described under Crania anomala and need not here be
repeated. Colour light yellow or light brown. Length G lines, breadth 7 lines.

190 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

Hah. Mediterranean and iEgean Sea, attached to rocks and coral at a depth of from
40 to 150 fathoms (Forbes) ; Gulf of Lyons, Banyuls-sur-Mer, in from 50 to 60 metres,
on rocks (L. Jouhin).

Obs. This Mediterranean shell seems to have been described for the first time by Poll
in 1795. He gave enlarged illustrations of the interior, to show the position of the
principal muscles, mouth, labial appendages, and vascular impressions ; but, strange to
say, he described the animal under the name of Criopus, and the shell by that of Criopo-
derma. As observed by Dall {loc. cit. p. 36), " Poll evidently considers Anomia as a
synonym, and only uses it by way of explanation. It is evident that such a system of
nomenclature as the above can never be fairly squared ^vith the binominal system."

By some malacologists Crania tarhinata has been considered to be the same as
or a synonym of Crania anomala, by Dall as a variety of the last-named species,
and by some others as a distinct form. I have therefore preferred to leave it, for
tlie present at least, as a separate species. It certainly bears considerable resem-
blance to the northern form, yet it possesses some peculiarities of its own. It is, on the
whole, a smaller shell, differing in colour as well as in some of its interior details. Its
upper valve is generally less conical ; but exceptional examples of the Mediterranean
shell are quite as conical or limpet-like as some of those that occur in the northern seas.
Crania turhinuta is often much out of shape from having its thickened lower valve
attached to corals, to which it moulds itself, as in the case of the specimen figured by
Sowerby in pi. xxvi. fig. 3 c of the ' Transactions ' of the Linnean Society of London for
1818, under tlie name of Crania personata. Sowerby considered that species and
C. auomala to be one species ; for he says that " the only difi'erence observable between the
specimens from Shetland and those from the Mediterranean is in the thickness and
irregularity of the lower valve ; those from the latter sea being very thick and irregular ;
wliereas those from Shetland are much thinner and more regular in their shnpe ; but this
difference, I imagine, may be easily accounted for from the different situation of the
respective specimens ; the one being found upon rugged old corals, and the other being
attached to a comparatively smooth stone." (See Plate XXVII. fig. 22.)

This is no doubt the case with respect to the Mediterranean form. On a specimen of
coral now before me three examples of the lower valve are attached, one of these, affixed
to a flat portion of the coral, is perfectly regular in shape, the other two being attached
to the circular part of the coral are irregular in form, the shell having been obliged to
follow the irregularities of surface, which were imparted to the shell itself.

There appears to be likewise a good deal of difference in the shape and projections or
depressions of the mvxscular scars in different specimens, and it is on these differences
that Hoeninghaus seems to have established his Crania rinc/ens (Plate XXVIII. figs.
1-1 «) and C. rosirata (Plate XXVII. fig. 21), both Mediterranean shells, which I
believe to be synonyms of the Crania tnrhinata of Poll. The so-termed C. ros-
trata figured by Reeve in his Conch. Icon, does not agree with Iloeniughaus's
figures of his species. Thus in the type of C. rin(jens the divaricator scars are
figured as large sunken-iu depressions, only slightly separated, and the occlusors as
formed of a large transverse oval-shaped scar, no rostellum being present ; while
in C. rosirata the divaricators are more separate, and the adductors have a more

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 191

or less developed and projecting rostcUum. These extremes, however, will vanish wlicn
a number of specimens are examined, and every intermediate form will be found
connecting the two extremes. The intimate shell-structure of Crania turhinata
seems very much the same as that of C. anoniala, but when describing the structure
of the attached valve of C. anomala. Prof. King observes, " Crania ringens (Hoeniug-
haus) [iin'bii/ata, Poli] has afforded me more information ; inasmucli as the same
valve, which is thick, and adhering to coral, shows, in a vertical section, the perfo-
rations distinctly passing direct downwards, and traversing nearly its entire thickness ;
becoming forked and attenuated as they approach the attached surface."

I know nothing of the species (?), which Sowerby and Pueeve erroneously, I think,
refer to the Crania rostrata of Ilccninghaus *.

Sowerby and Reeve describe it as follows : — " Shell with the lower valve rotundately
subtrapczoidal, posterior margin rather straight, posterior scars orbicular, the anterior
small, semilunar, anteriorly coalescing, rostellum small, rather sharp, disk sinuated, rim
grained, anteriorly irregular, thickened ; upper valve thinner, white, somewhat radiately
roughened, interior with two raised ribs radiating from the centre towards the posterior
margin."

No fresh observations have been made on this species since the publication of Mr.
Sowerby's monograph of the genus in 184-6, and his characters are copied by Reeve
verbatim. Its habitat, Mr. Cuming informs me, is " not the Mediterranean, as given by
Sowerby, but South Africa."

104. Crania japonica, Adams. (Plate XXVII. figs. 10, 11.)

Crania japonica, A. Adams, Ann. & Mag. Nat. Hist. vol. xi. p. 100, 18C3 ; Davidbon, Proc. Zool. Soc.
p. 311, pi. XXX. fig. 6, 1871; Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 199, 1873; G. Duuker,
Index Moll. Maris Japonici, p. 254, 1883.

Shell small, almost squ.are, with rounded angles, nearly straight or slightly indented
posteriorly, rounded laterally and in front. Upper valve conical, vertex situated at
about one third of the length of the valve from the posterior margin ; surface smooth,
marked with concentx'ic lines. Lower valve almost flat, attached to marine objects by
its exterior surface. In the interior of the upper valve a narrow margin encircles the
valve, and close to the posterior margin are two slightly oblique oval-shaped projecting
divaricator muscular scars widely separated from one another ; towards the middle of
the bottom of the valve two large oblique projecting elevated oval-shaped adductor mus-
cular projections arise, gently excavated along their middle ; these scars are so large that
they almost divide the valves into two portions, and are separated at the middle of the
shell by a blunt ridge, which extends some distance towards the front. In the
interior of the lower or attached valve the adductor and divaricator muscular scars
occupy a similar position to those in the upper valve, but do not project nearly so
much. Colour dirty white. Length and breadth 3| lines.

Hab. Dredged by A. Adams at Gotto, Japan, in 71 fathoms.

* Crania rostrata, Sowerby, Thes. Couch, p. ;j(iS, pi. Ixxiii. figs. 12-14, Ib-lU : L. Keevc, Conch. Icon., Monogr. of
Cra7ua, pi. i. fig. 3, 1862.

SECOND SERIES. — ZOOLOGY, VOL, IV. '2('>

192 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

Ols. This appears to be a distinct species, remarkable on account of the large size
and projection of its adductor scars, which remind us of those described and figured
by P. W. Hoeninghaus in the Tertiary Crania abnormis of Def ranee.

Crania japonica was briefly described, but not figured, by A. Adams in 1863. I
figured in 1871 the type specimen presented to me by its discoverer.

106. Ckania Suessii, L. Reeve. (Plate XXVII. fig. 13.)

Crania Suessii, L. Reeve, Conch. Icon., Monogr. of Crania, pi. 1. fig. 2, 1862; Dall, Amer. Journ. of
Conch, vol. vii. p. 73, 1871 ; Bull. Mus. Corap. Zool. Harvard, p. 32, 1871 ; Proc. Acad. Nat. Sci.
Philadelphia, p. 199, 1873.

"Shell sub-orbicular, somewhat truncately squared on the posterior side, posterior
scars ovate, oblique, rostellum large, callous, anterior rim thickened, granulated ; upper
valve rather solid, rough, faintly tinged with orange-red, internal posterior scars
narrowly ovate, obliquely flowing together.

" Hab. Sydney (Strange).

" Obs. Of this interesting Australian Crania Mr. Cuming possesses five specimens,
collected by Mr. Strange at Sydney. It comes very near to the West-African species
which has been assigned to C. rostrata of Hojniughaus, but it is of a more convex and
roughly solid growth ; and the diff'erence of habitat leaves no room for doubt on the
subject. The internal posterior scars of the lower valve are obliquely ovate and
somewhat isolated, while in the upper valve they are narrow and callously raised. The
rostellum is large and prominent. Another character is the delicate tinge of orange-red
on the outer surface, qu.ite diflferent to the red stained colouring of the European
species." — L. Reeve.

I have reproduced Mr. Lovel Reeve's descriptions and figures of this species, as I know
so little of it. Mr. John Brazier, of Sydney, informs me that he has neither found nor
seen a specimen in Australia ; the above reference to Sydney therefore seems doubtful,
furthermore, if found by Strange in Australia, it would probably be at Moreton Bay, a
locality in which he collected extensively.

Family DISCINID/E, Gray, 1840.

Genus DISCINA, Lamarck, 1810.

Type Discina ostreoides (Rang)= Cr««i« striata (Schumacher).

Eor many years the recent species of this family were classed with Orbicula. In
1825, in the ' Annals of Philosophy,' Dr. Gray pointed out that Orbicula was a
synonym of Crania, and that it Avas necessary to adojit Lamarck's excellent genus
Discina, a view now generally admitted. In his ' Revision ' of the Craniidse and
Discinidse published by Mr. W. H. Dall in the ' Bulletin of the Museum of Comparative
Zoology, Harvard,' vol. iii. p. 37, 1871, the author proposes to divide the recent species
into two subgeneric groups as follows : —

Genus DISCINA, Lamarck. Type D. striata, Schumacher, sp., 1817.

Subgenus Discina, sensu stricto. Slicll with subequal externally convex valves, with, subcentral
apices. Lower valve with a small subtriangular longitudinal septum or prominence in the centre,

Smooth species.

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 193

with a minute circular orifice beneath it, for the peduncle, i'rom which an impressed line or
furrow extends on the inside, posteriorly, for a short distance. Shell of rather solid texture,
impunctate ; perfoi-ated by very minute tubuli (?). Type D. striata, Schum. = Z). radiosa, G:\(i.
+ D. Evansi, Dav. + Z). norvcgica, Sby. + X). ostreoides, Lamarck.

Subgenus Discinisca, Dall, = DisciNA, auet. Lower valve more or less flattened, concave or com-
pressed. Ujiper valve more convex ; apices of both subceutral or subpostcrior. Lower valve
with a small septum as in Discinu, behind which is an impressed disk or area, externally
concave, and internally elevated. This is perforated by a longitudinal fissure, extending from a
short distance behind the septum nearly to the posterior margin, which is often slightly indented
behind it. Shell more or less horny in texture, minutely tubulous. Type Discina lamellosa,
Brod. Rve. Conch. Icon. pi. i. fig. 4, 1862.

We are acquainted with only one recent species of Discina proper, namely the Discina
striata of Schumacher.

Of Discinisca we have the following : —

Discinisca Icevis, Sowerby, sp., 1818 (or 18.22).

Discinisca tenuis, G. Sowerby, sp., 1817 (may be only a variety of the pre-
ceding species).
Discinisca lamellosa, Broderip, sp., 1833.
Discinisca atlantica, King, sp., 1868.
r Discinisca Cumingii, Broderip, sp., 1833.
Radiately striated. \ ? Discinisca antillarum, d'Orbigny, sp., 1853 (an uncertain species).
I Discinisca stella, Gonld, sp., 1860.

106. Discina striata, Schumacher, sp. (Plate XXV. figs. 18-20.)

Crania striata, Schumacher, Essai d'uu Nouveau Systeme des Hab. des Vers Test. pi. xx. fig. 1, 1817
(not of Defrance).

Orhicula norveyica, Sowerby, Trans. Linn. Soc. vol. xiii. p. 464 (syn. excL), pi. xxvi. fig. 2 a to f,
1818 (not of Lamarck).

Discina ostreoides, Lamarck, An. sans Vert. vol. vi. p. 337, 1819.

Orhicula ostreoides, Rang, Man. des Moll. p. 263, 1829.

Discina ostreoides, T. Brown, Conch. Textbook, ed. 3, p. 108, pi. xiv. fig. 8, 1835.

Orhicula striata, G. B. Sowerby, Thes. Conch, vol. i. p. 366, pi. Ixxiii. fig. 8, 1846.

Crania radiosa, Gould, Moll. U. S. Expl. Exped. p. 465, fig. 480 a-c, 1852.

Discina striata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 376, 1852.

Orhicula Evansii, Davidson, vVnn. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 376, 1852 ; and Proc.
Zool. Soc. 1852, p. 81, pi. xiv. figs. 32-34.

Discina striata and D. Evansi, E. Suess, Ueber die Wohnsitze dcr Brachiopoden, Sitzungsb. k.
Akad. Wissensch. Wicn, Bd. xxxvii. pp. 225 & 226, 1859.

Orhicula ostreoides, L. Reeve, Conch. Icon., IMonogr. of Orhiciila, no. 7 , pi. i. fig. 7 a-h, 1862.

Discina striata, Dall, Bull. Mus. of Comp. Zool. Harvard, vol. iii. p. 39, 1871 ; and Cat. of the Recent
Species of the Class Braehioiroda, Proc. Acad. Nat. Sci. Philadelphia, p. 300, 1873.

Shell elongated oval or circular, generally irregular in shape, sometimes exceedingly
thick. Valves convex. Upper valve conical and more or less elevated. Apex sub-
marginal, sometimes central. Lower valve less convex than the upper one, perforation
or foramen small, oblique, situated at about one third of the distance from the posterior
margin. Surface of valves radiately finely striated, the narrow riblets increasing in
number by the interpolation of shorter ones at various distances from the vertex or

26*

194 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

foramen. The valves are also strongly marked with concentric lines or ridges of growth.
In the interior of the generally much thickened vipper valve the muscular scars
occupy the margins of a rather large sunken space ; there are four obliquely placed
adductor scars — two are situated at a short distance from the posterior margin of the
valve and are separated by two very small retractor muscular impressions. The second
pair of oval-shaped adductor scars are obliquely situated towards the middle of the
bottom of the valve, Avith a narrow ridge between them which extends some distance
along the bottom of the cavity in the shell. In the interior of the loAver valve the
adductor muscular scars meet in front of a small longitudinal septum, which rises
from the centre, hiding a small tubular perforation which traverses the valve in an
oblique manner ; the posterior adductor scars are small and widely separated. Shell-
structure horny and calcareous. Colour yellow and brownish yellow. Length 8^
lines, breadth 8 lines.

JUab. Cape Palmas, West Africa.

Ohs. Mr. W. H. Dall has given much attention to the history and identification of the
species under description. He states in his Heport on the Brachiopoda obtained by
the United States Coast Survey Expedition, loc. cit. p. 40, " when changes in nomen-
clature depend upon the identification of types described by the early authors, the
work is one of great difiiculty, and requires the utmost caution, lest fresh confusion be
the result. In many cases an approximation to a determination alone can be arrived
at, and authors may conscientiously difi"er as to the decision, and its bearings on
nomenclature. In the present case, however, there is but little difficulty, as the
species under consideration has been well described and carefully figured by the
describers, though under several names [both generic and specific] ; the history of the
type specimens is very clear, and was put on record at the time.

"Lamarck constituted the genusD/sc/^rt to receive a shell which he called i>. ostreoides,
but of which he did not give any figure or specific description. The specimen was
received from Mr. J. Sowerby, and is the same species and from the same lot of speci-
mens as the shell described by Mr. G. B. Sowerby, in the Linnean 'Transactions,' and
well fio-ured by him there, under the name of Orhiciila norvegica. His very excellent
fio-vire enables me to speak with positiveness in saying that it is identical with Crania
radiosa, Gould, of w^hich the type specimens are before me. The figures of Schumacher
are sufficiently exact to allow of identifying the species with his Crania striata. The
figures given by Reeve and Davidson are excellent, and almost certainly represent the same
species, though this is a matter of little consequence, the main point being the identifica-
tion of Sowerby 's shell with the specimens before me, which may be regarded as certain."

If therefore Schumacher's so termed Crania striata and Lamarck's Discina ostreoides
represent the same shell, then of course Schumacher's specific name must be retained for
the species. As remarked by Mr. L. Eeeve, the species was named ostreoides by
Lamarck from a specimen sent to him in 1819 by Mr. James Sowerby, father of Mr. G.
B. Sowerby, who described it in the following year in a paper read before the Linnean
Society under the name of Orhicula norvegica. He had then discovered it in abundance
in the crevices of a quantity of ballast-stone used in the neighbourhood of Lambeth for
mending roads, and it was again described by G. B. Sowerby in 1816, under the name

DE. T. DATIDSON ON RECENT BiJAClIIOPODA. 195

of Orhictda striata. The same shell was also found some years ati^e by Mr. L. Binncy in
ballast-stone on the shores of the Clyde near Glasgow.

It should also be recorded here that in a paper entitled " Observations on the Synonima
of the Genera Anomia, Crania, Orhicula, and Discina" published in the ' Annals of
Philosophy ' for 1825, Dr. J. E. Gray, of the British Museum, maintained that the genus
Discina -was established for the species under description. Both Mr. Dall and Mx.
Reeve have referred my Orhicula Bvunsi to Schumacher's or Lamarck's species, and
I am quite willing to agree to their identification.

Subgenus Discinisca, Dall.

107. Discinisca l^vis, Sowerby, sp. (Plate XXVI. figs. 1, 9-11.)

Orhicula Icevis, Sowerby, Trans. Linn. Soc. vol. xiii. p. 468, pi. xxvi. fig. 1, a-d, (read in 1818) pub-
lished in 1822; G. B. Sowerby, Thes. Conch, i. p. 265, pi. Ixxiii. fi-s. 2, 3, 1846; Davidson, Ann. &
Mag. Nat. Hist. 2nd ser. vol. ix. p. 376, 1852.

Discina Icevis, E. Suess, Ueber die Wohnsitze der Brachiopoden, Sitzungsb. k. Akad. "Wissensch. Wieu
Bd. xxxvii. p. 226, 1859.

Orhicula Icevis, L. Reeve, Monogr. of Orhicula, Conch. Icon. pi. i. figs. 4 & 5, 1862.

Discina Icevis, Dall, Amer. Journ. of Conch, vol. vii. p. 76, 1871 ; Bull. Mus. Comp. Zoiil. Harvard,
vol. iii. p. 42, 1871 ; and Proc. Acad. Nat. Sci. Philadephia, p. 201, 1873.

Shell horny, almost orbicular, and nearly as wide as long, a little broader and more
rounded anteriorly. Surface either nearly smooth or more or less strongly marked with
concentric lines or ridges of growth. Upper valve compressed, limpet-like, or gently
conical. Vertex submarginal. Lower or smaller valve moderately convex, most
elevated towards the middle at about one third the length of the sliell from the posterior
margin. Central third of the posterior half of the valve abruptly depressed, with a
flattened, smooth, oval, or heart-shaped disk, wdiich does not quite reach the slightly
indented posterior margin of the shell. Along its centre an oval-shaped, narrow,
longitudinal fissure extends to within a short distance of the posterior ridge of the
disk, and through which a short stout peduncle passed, which expanded all over the disk
prior to becoming cylindrical, and again expanded at its extremity, where it became
firmly attached to some marine object. In the posterior half of the interior of the
larger valve a slightly sunken oblong depression occupies rather more than a third of the
breadth of the shell, and commences at some little distance from the posterior margin of
the valve. It is of an oblong shape, almost straight posteriorly, slightly indented
laterally and obtusely angular anteriorly. Along the posterior edge or portion are tw^o
transversely oval-shaped adductor scars, sejiarated by two other very small impressions
attributed to the retractor muscles ; on the anterior portion of the depressions or disk
are two larger obliquely placed adductor impressions, separated by a small rudimentary
ridge. In the interior of the smaller valve an elevated or convex disk occupies the
central third of the posterior half of the valve, and along the middle is a narrow oval-
shaped fissure, which extends along the disk to about half its length ; anteriorly a small
triangular-shaped septum divides the anterior pair of adductor muscles. Mantle highlv
vascular, fringed w^th setae, which extend to fully one third of the length of the shell
and beyond the margin of the shell. The labial appendages curve backwards, return

196 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

upon themselves, and end in a small spiral directed downwards. Colour light yellow or
chestnut-brown. Length 15 lines, breadth 14^ lines.

Hal). Great Ocean from Cobija (Bolivia) to the Island of San Lorenzo, Concepcion,
Chili (15 fathoms). It was obtained by Mr. F. H, Bradley at Callao, Peru, clustered
together in vast numbers and adhering in all stages of growth by its peduncle to the
surface of the shells of its neighbours, till a living mass of considerable breadth and
thickness was formed, living at a depth of six or more fathoms.

Ohs. On the 17th of March, 1818, Mr. George B. Sowerby read before the Linnean
Society a paper on the genera Orljicula and Crcmia of Lamarck, in which for the first
time he introduced his Orbicula leevis, with good figures of the exterior and interior of
the valves. It can hardly be said that he described the species ; for all he said of it was,
" Orbicula leevis, 0. valvulis tenuibus Irevibus, tab. xxvi. fig. 1. Habitat in mari, saxis
adha^rens." In 1862, Mr. Lovel Reeve, in his monograph of Orbicula, states that " this
species was first described by Mr. Sowerby in a paper read before the Linnean Society
in December 1820, from a specimen attached to a grey flint or pebble nearly coated by
the roots of an Isis, of which the habitat was not known. Twelve years later it was
found attached to shells dredged by Mr. Cuming, as above noted, off Concepcion, Chili.
It is a stout horny shell, with surface smooth and faintly malleated. The vertex, which
much inclines posteriorly, is conically raised, swollen and rather obtuse."

What we know of the animal of this species will be found recorded under Liscinisca
lamellosa. Having had before me a very large number of typical specimens and others
of Discinisca leevis, D. tenuis, and D. lamellosa, I am much inclined to consider them as
variations in shape, or varieties of a single species; but as malacologists generally seem to
differ with me in this respect, I will provisionally describe them separately. If a large
number of specimens of Discinisca leevis are examined, especially those from Callao and
Peru, it will be found that some of them are smooth and marked only by numerous fine
concentric lines. In some these lines are more strongly defined, and, again, in others they
are replaced by thin rows of adpressed or gently raised lamella3, which roughen the surface
of the shell. I am also of opinion that fig. 5 of plate i. of Beeve's Monogr. of Orbicula,
and referred by him to Orbicula tenuis, is no more than a smoother shell of Discinisca leevis.
If it should be therefore eventually found necessary to unite D. leevis, D. tenuis, and D.
kimelloset under a single denomination, the name leevis would have to be retained for the
species.

108. Discinisca tenuis, Sowerby, sp. (Plate XXVI. figs. 12-17 a.)

Orbicula tenuis, G. B. Sowerby, Tlies. Condi, vol. i. p. 3GG, pi. Ixxiii. figs. 4, 5, ]847; Davidson, Ann.
& Mag. Nat. Hist. 2ud ser. vol. ix. p. 376, 1852.

Discinisca tenuis, Dall, Bull. Mus. Comp. Zool. Harvard, vol. iii. p. 41, 1871.

Shell elongated, orbicular or circular, broadest anteriorly, thin, horny, semitransparent,
shining, smooth, marked only by fine concentric lines of growth. Colour light yellow
or pale yellowish brown. Upper or larger valve moderately convex, limpet-like;
apex small, slightly hooked, submargiual. Anterior half of lower or sinaller valve and
lateral portions of the posterior half convex, less so than in the opposite valve ; highest
elevation about the middle ; larger portion of the posterior half of the valve abruptly
sunken ; disk oval-shaped, commencing close to the posterior margin, extending to

DE. T. DAVIDSON ON EECENT BRACHIOPODA. 197

the middle of the valve and forming an obtuse angle with the plane of the sunken
portion. Fissure oval-shaped, rather narrow, commencing close to the posterior margin
of the valve and extending a little more than half the length of the disk. In the
interior of the valves the muscular and other impressions are exactly similar to those
seen in Discinisca Jcevis and D. lamellosa. Length 13 lines, breadth 12 lines.

Hah. Uncertain.

Ohs. Sowerby describes this species in the following words : — " Shell smooth, thin, apex
of the upper valve near the posterior margin ; disk of adhesion obtusely angular, close
to the hinder edge; perforation linear." Sow^erby's figures 4 and 5 are somewhat
exceptional, the larger number of specimens given to me by Mr. Sowerby being more
regularly oval, and even rounded, and nearly resemble some of Liscina Icevis from
Concepcion, Chili. The group of specimens attached to one another figured by L. Reeve
on pi. i. fig. 5 of his Monogr. of Orhicula seem to me and, I believe, also to Mr. Dall
more referable to Discinisca IcEvis than to the variety (?) D. temds of Sowerby.

109. Discinisca lamellosa, Broderip, sp. (Plate XXVI. figs. 1-S.)

Orbicula lamellosa, Broderip, Trans. Zool. Soe. vol. i. p. 142, pi. xxiii. fig. 2, 1835; Owen, On the
Anatomy of the Brachiopoda, Trans. Zool. Soe. vol. i. p. 153, pi. xxiii. figs. 2-13, 1835 ; Anton,
Verzeiehniss der Conch, p. 21, 1839; G. B. Sowerby, Thes. Conch, vol. i. p. 3G5, pi. Ixxiii. fig. 1, 1846;
Davidson, Ann. & Mag. Nat. Hist. vol. ix. 2nd ser. p. 376, 1852, and Intr. to Br. Foss. Bracli. vol. i. p. 127,
figs. 47-49, 1853; A. d'Orbigny, Voyage dans I'Amerique meridionalc, vol. v. p. 077, 1817.

Discina lamellosa, S. P. Woodward, A Manual of the Mollusca, pp. 336, 337, figs. 160-1(32, 1856;
H. & A. Adams, The Genera of llecent Mollusca, p. 584, pi. xiii. fig. 4, 1858 ; E. Suess, Ueber der
Wohusitze der Brachiopoden, Sitzungsb. k. Akad. Wissenseli. Wieu, Bd. xxxvii. p. 227, 1859.

Orbicula lamellosa, L. Reeve, Conch. Icon., Monogr. of Orbicula, pi. i. fig. 3, 1862.

Discinisca lamellosa, TfaW, Bull. ]Mus. Comp. Zoiil. Harvard, vol. iii. p. 41, 1871, and Proc. Acad.
Nat. Sci. Philadelphia, p. 202, 1873.

Discina lamellosa, Davidson, Brit. Encycl. 9th ed. p. 188, fig. 10, 1876.

Discina [Discinisca) lamellosa, Zittel, Handbuch der Paliiontologie, p. 667, fig. 491, 1880.

Discina lamellosa, L. .Joubiu, Comptes Rendus, t. ci. p. 1170, 1885 ; Arch. Zool. exper. t. iv. 2° ser.
p. 161, pis. 13, 14, 1885.

Shell circular or orbicular, about as broad as long, horny in substance ; valves convex,
somewhat depressed ; colour light chestnut-brown, disk in lower valve w'hite. Upper
or larger valve compressed, conical, or limpet-like, vertex submarginal or situated at
about one third of the length of the shell from the posterior margin, concentrically
lamcllose ; anterior half or two thirds of the low^er valve moderately convex ; in poste-
rior half there exists a sunken and perforated disk ; fissure narrow, commencing at a short
distance from the posterior margin, and extending to about two thirds of the length of
the disk of adhesion. Surface, with the exception of the disk, covered with numerous
squamose, slightly projecting, concentric lamina) (as in the upper valve). In the interior
of the larger valve rather more than one third of the posterior half of the valve is occupied
by an oblong space, on part of which are situated the scars left by the adductor muscle ;
the posterior pair are on a horizontal line at a short distance from the margins of the
valve, and separated by two very small scars attributed to the retractor muscles (?). The
anterior pair of adductor scars are obliquely placed at about the middle of the valve, and
are larger than the posterior ones. In the interior of the smaller valve the disk forms an

198 DE. T, DAVIDSON ON EECENT BEACHIOPODA.

elevated, convex, oval-shaped area, with a small, sharp, central, triangular-shaped promi-
nence in front of the foramen, which separates the anterior pair of adductor muscular scars.
The fissure, which is narrow, begins at a short distance from the posterior margin, and
extends to about two thirds of the length of the disk. The animal is extremely delicate
and transparent ; mantle-lobes distinct all round and not adliering to the interior of
the shell, which is smooth and polished, highly vascular, bordered with a dense fringe
of long horny setae, which are stiff, barbed, and extremely brittle. Labial folds united,
not extensile. Spiral extremities of the arms directed towards the lower valve, and not
dorsally, as in Crania. Length and breadth nearly 1 inch.

Sab. Iquiqui, adhering to living Mi/iilus, and Bay of Ancon, Peru. From Panama ta
Peru (Cuming). It occurs in groups or piled one over the other in vast numbers on
sandy bottoms and at depths of from 5 to 9 fathoms. Mr. Reeve mentions that at Ancon
Discmisca lamellosa was found attached to dead shells, also clinging to the wreck of a
Spanish vessel of about three hundred tons that went down in the bay about ten years
before. A. d'Orbigny states that it is common on all the shores of the Great Ocean, from
Cobija (Bolivia) to Callao (Peru), and that be has obtained it in shallow sea in great
nu.mbers near the island of San Lorenzo.

Ohs. This species has been well figured by Broderip, Sowerby, L. Beeve, and others.
The animal was anatomically described and illustrated by Owen in the Trans, of the Zool.
Soc. of London, vol. i. 1835, as well as by Dr. S. P. Woodward and myself in 1852 *.

Prof. Owen states (p. 153, loc.cit.): — " On carefully removing the imperforate valve,
the vascular mantle is seen with the margin entire in the whole of its circumference.
The muscles and viscera form a rounded mass, situated in the posterior half of the shell.
First are seen the extremities of two muscles, of an oblong figure, converging ante-
riorly, and measuring two lines by nearly one : in the triangular space between these
muscles is situated the green liver, behind which is the grey ovary ; and at the poste-
rior part of the circle are the extremities of two smaller muscles. The four impressions
of these muscles are observable on the interior of the shelly valve.

"On removing the lower valve, which should be cut through from either side as far as
the fissure in order to avoid disturbing the soft parts, the vascular lobe of the mantle
with similar free margins is exposed, but the viscera are quite concealed by the dilated
disk or foot.

" Each lobe of the mantle can be reflected from before backwards to the extent of five
lines, and from behind forward to the extent of half a line, but they adhere too closely
to the visceral mass to be detached without laceration. When so reflected, the branchial
vessels may be seen in rich profusion on their inner surface.

* [More recently Dr. L. Joubin has described (loc. cit. p. 33) the mantle of Dtsdiui as a thin membrane, closely
adherent, with a thickly ciliated border. It acts as a respiratory organ, bounds the visceral cavity, and contains
arborescent prolongations of the body-cavity as in Crania. The main vascular trunks are subdivided into branches
having numerous little orifices at their terminations. There is no trace of a heart or arterial system. The genital
o-lands resemble those of Crania and Lingula. The arms cannot be extruded beyond the shcU-margins ; the cirri are
thick and very long. The peduncle, which diifers much from that of Lin<jula, is formed of a fold of the mantle ; and,
being enclosed as in a sac, is entirely separated from the body-cavity. This structure is identical with that subse-
quently sliown by the same author (BuU. Soc. Zool. do Franco, vol. sii. 1SS7, pp. ll'J-126) to exist in young forms
of the articulated genera Ar<jiope and Terehratidhia. — A. C]

DE. T. DAVIDSON OX RECENT BRACHIOPODA. 199

" Ou the lobe of the mantle which Hues the imperforate valve these vessels are seen
converging from the respiratory margin to four trunks, which are much shorter than
the corresponding ones in Terehratula : on the opposite mantle-lobe the branchial vessels
form only two such trunks.

" In this profuse distribution of vessels over a plain membranous expansion, we
perceive the simplest construction of the water-breathing organ, or Iranchia ; and while
it proves the close affinity of the Brachiopoda to the Ascklui;, it presents, at the same
time, a beautiful analogy Avith the elementary forms of the air-breathing organ, as it
exists, for example, in \h.Q pulmomferous Gasteropods.

" The muscular system of Orbicula differs iu some respects from that of Terehratula.
Eight distinct muscles may be perceived, without including the labial arms. The four
thick and strong muscles which form the anterior and posterior pairs above noticed, do
not decussate each other, but pass a little obliquely from one valve to the other. On
the lower valve they are attached to the margin of the elevation caused by the oval
depression noticed on the exterior of the sliell. Some of the fibres of the large anterior
pair pass through the chink in the perforated valve and expand into the organ of
adhesion. "Within the space included by the above pairs of muscles, there are two
slender pairs of muscles which decussate each other. The superior pair take their origin
from the anterior part of the strong membrane that circumscribes and protects the
viscera below the stomach, and between the insertions of the anterior shell-muscles ; they
then ascend, diverge on either side of the alimentary canal, and are inserted into the
opposite valve outside the posterior shell-muscles. The inferior pair arise from the sides
of the membranous circle, and converge as they pass below the preceding, to be inserted
into the perforated valve on the inner side of the posterior shell-muscles. While, there-
fore, the larger muscles have the more important office of guarding the animal by closing
the shell, the smaller muscles woidd admit the Avater by sliding the margin of one valve
over the other ; and they are also calculated to produce a compression of the viscera.

"The labial processes or hrachla are scarcely more adaj^ted to protrude externally
than in Terehratula chilensis, the only parts that are free being the short spiral extre-
mities ; but in the more muscular character of their basis or stem they exhibit a close
affinity with Linrjula. Considering the arms as a pair, the stems are tlien joined below
the mouth, forming on that aspect a transverse, semilunar, fleshy basis, fringed and
convex anteriorly. This is attached to the anterior part of the tendinous belt of the
viscera. At the sides of tliis basis the arms make a sudden bend upon themselves
towards the mouth, above and in front of which the extremities make a sjoiral turn and a

half. The bent portions are closely adherent to each other, not free, as in Lingula

The arms in Orhicida are not, however, suj^ported by an internal calcareous process.
The muscular basis, when cut into, exhiljits on each side a well-defined cylindrical cavity,
which commences near the mesial plane in the transverse part below the mouth, and is

continued into the spiral extremity But I conclude, nevertheless, tliat the

canals serve to extend outwards the free spiral extremities, by being forcibly distended
with fluid propelled along them.

"The mouth, a small puckered orifice, is best seen by dissecting away the transverse

SECOXD SERIES. — ZOOLOGY, VOL. IV. 27

200 DE. T. DAVIDSON OX EECENT BEACHIOPODA.

basis of the arms. The oesophagus passes obliquely through the tendinous wall of the
viscera in a direction towards the upper or imperforate valve; having then passed
between the anterior shell-muscles, it becomes slightly dilated and surrounded by the
liver, forming a less capacious stomach than in Terehratiila. The intestine is continued
straight to the opposite end of the visceral cavity, and is there again contracted, and
making a sudden bend upon itself, passes in a slight sigmoid curve to the middle of
the right side of the visceral belt, w'hich it perforates obliquely, and terminates between
the lobes of the mantle about half a line below the bend of the arm. The liver is of a
beautiful* green colour ; it is a congeries of elongated follicules closely compacted

together, which communicate by numerous orifices with the stomach The coats

of the stomach and intestines are thick and pulpy, and apparently glandular. Posterior
to the liver the whole of the visceral cavity not occupied by the muscles and vessels is
filled with grey masses of ova.'" Owen also detected traces of the nervous system.

Prof. E. S. Morse states, in his paper on the systematic position of the Brachiopoda
(Proc. Boston Soc. Nat. Hist. vol. iv. 1873, p. 21), that Fritz Miiller has shown that in
the embryo of Discina there are remarkably barbed setae of great length, which are
afterwards discarded. The shell-structure of Discina is very similar to that of the genus
Lingnla, to which we have alluded under Liiigula anatina. That of Discina has been
carefully described by M. S. Cloez in the pages of the ' Institut,' p. 240, 1859, and is
also referred to by Dr. Gratiolet in his admirable memoir " Etudes anatomiques sur la
Litiffula anatina, Lamarck," Journal de Conchyliologie, vol. viii. 2" scr. 1860.

110. DisciNiscA ATLANTiCA, King, sp. (Plate XXVI. figs. 18-22.)

Discina atlantica, King, Proc. Nat. Hist. Soc. Dublin, vol. v. pp. 170-173, 1868.

Discinisca atlantica, Dall, Cat. Recent Bracli., Proc. Acad. Nat. Sci. Pliiladclphia, p. 177, 1873.

Discina atlantica, Jeffreys, Ann. &Mag. Nat. Hist. 4th ser. vol. xviii. p. 252, 1876, and Proc. Zool. Soc.
1878, p. 415 ; Davidson, Report on the Scientific Results of the Voyage of H.M.S. ' Challenger,' Zool.
vol. i. p. 62, 1880.

Shell small, slightly oval longitudinally, broadest anteriorly, sometimes marginally
almost circular. Shell very thin, semitransparcnt, corneous, marked with numerous
concentric lines or ridges of growth. Upper valve conical; vertex situated at about
one third of the length of the valve from the posterior margin : ventral valve exceedingly
thin, fissure small, longitudinally oval. Colour light yellowish brown. Length and
breadth 2i lines, height 1\ lines.

Hab. This small species was not known previous to 1862. Since then it has been
dredged in nine or ten separate and far distant localities. It appears to be a very
abundant shell, occurring only at very great depths. Prof. King, to whom we are
indebted for the first description and illustration of this interesting species, informs us
" that it was first dredged in 1862 by Staff-Commander Kichard Hoskyn, R.N., at the
time in command of H.M.S. ' Porcupine,' for purposes in connexion with the then-
proposed telegraphic connexion beti^ een Ireland and Newfoundland." The specimen
was not quite perfect, and " came up in the sounding-machine from a depth of 1210
fathoms, in lat. 52° 8' N., long. 15° 30', W., or nearly due west of Dingwall Bay."

DR. T. DAVIDSON OX EECENT BEACHIOPODA. 201

The second specimen was dredged by Dr. Gwyn Jeffreys, in nearly the same place, at
a depth of 130(5 fathoms, during the ' Porcupine ' Expedition, 1836. It was also dredged
by Sir James Anderson in the North Atlantic, wlien fishing up the telegraph cable,
in 2400 fathoms depth ; and again by Dr. J. Gwyn Jeffreys during the cruise of the
' Valorous ' in Baffin's Bay, at depths of 1-450 and 090 fathoms.

Discina atluntica was obtained at seven or eight different localities by the ' Challenger '
Expedition. In lat. 1° 47' N., long. 24° 26' W., attached to Llmopsis aurita, Brocchi,
and associated with one example of Megerlia incei'ta, Davidson, at a depth of 1850
fathoms. This station is situated between the Cape Verde Islands or Sierra Leone
(Africa) and Fernando Noronha (South America). Again in lat. 4° 33' S., long. 120°
58' E., depth from 200 to 360 fathoms, attached to volcanic detritus ; also in lat. 34°
37' N., long. 140° 32' E., depth 1875 fathoms, associated with one example of Terehra-
tula (?) Lain. In lat. 36° 10' N., long. 178° 0' E., depth 2050 fathoms, attached to
fragments of pumice-stone; in lat. 0° 33' S., long. 151° 34' W., at a depth of 2425
fathoms ; in lat. 33 °31' S., long. 74° 43' W., depth 2100 fathoms, along with Wald-
heim'ui JVyvilU; and, lastly, in lat. 12° 8' S., long. 145° 10' E., off Australia, at a depth of
1400 fathoms.

Dr. Alleync Nicholson observes that abyssal or deep-sea forms are usually widely
diffused, their range depending chiefly on temperature and being influenced mainly by
oceanic currents.

Obs. I believe I liave seen nearly all the upper valves of this small species hitherto
collected, but only one specimen of the smaller valve. Dr. Gwyn Jeffreys, in his paper
" On North-Atlantic Brachiopoda," published in the Ann. & Mag. Nat. Hist, for Sept.
1870, says (p. 252) that the " arms (labial processes) are furnished with very long aad
slender setae or stiff hair-like cilia, which project beyond the edge of the shell on every
side to an extent fully equalling its diameter." He meant, or should have said, from
the margin of the mantle, not of the arms. The brachial appendages are, as stated by
Dr. S. P. Woodward aud myself, curved backwards, returning upon themselves, and
ending in small spires directed downwards towards the ventral valve. Prof. Owen, who
in 1835 described with much care the anatomy of the genus Discina, says (pp. 155, 156),
" Tiie labial processes, or brachia, are scarcely more adapted to protrude externally than in
Terehrutula chilensis, the only parts that are free being the short spiral extremities. . . .
The brachial filaments, when viewed through the lens, presented an equal cylindrical
figure and an entire surface." He also minutely describes and illustrates the two lobes
q{ the mantle, and states that "the branchial vessels may be seen in rich profusion on
their inner surface." In a highly magnified view of a small portion of the edge of the
jnautle he shows the " terminal divisions of the branchial vessels and their setose cilia" *.

At my request Dr. Halifax, of Brighton, made for me a series of pi-eparations of the
mantle of both Llsclnisca lavls and D. atlantica. These last, from sptjcimens brought
home by the ' Challenger ' Expedition, showed in the most clear aud admirable manner
the highly vascular mantle, fringed witli long horny setic, entirely agreeing with the

* R. Owen, " On the Anatomy of the Brachiopoda of Cuvicr, and more especially on the Genera Terebratula and
Orlkula," Trans. Zool. Sue. vol. i. p. 145, pi. xxii. figs. 2-13, lS3o.

27*

202 DE. T. DAVIDSON ON EECEXT BEACHIOPODA.

descriptions of Prof. Owen and Dr. S. P. Woodward. The cirri are of great length and
barbed throughout, with spine-like asperities ; in some cases they bifurcate near their
extremities and lie close together at theii- origin. In some specimens of Discinisca Icevis
great numbers of full-grown PedicelllncB, a genus of Bryozoa, adhered to the long barbed
cirri, looking like Llngulce with their long pliant peduncles. The smaller valve of
Discinisca atlantica was thus described by Dr. Gwyn JeflPreys {loc. cit. p. 252) from a
North- Atlantic specimen obtained during the ' Valorous ' Expedition : — " Plat, thin,
having near its middle a comparatively small round disk, within which is an oval slit
for the passage of the byssal (peduncle) of attachment ; this disk is slightly sunk within
any calcareous substance to which it is attached, as if the byssus had the power of
excavation ; the rest of the lower valve is free and concentrically striate, like the upper
valve : muscular (adductor) scars in the upper valve, club-shaped, rather close together ;
no scars observable in the lower valve. Not the slightest trace of tubular or perforated
structure could be detected in either valve witli one of Smith and Beck's best micro-
scopes, under a lens of one-fifth power."

I have nothing further to state with reference to this species, which was fully described
in my ' Challenger ' Report.

I am not certain that Discinisca atlantica has been hitherto positively found in the
fossil state ; but Dr. Gwyn Jeffreys thinks that the Dlscina fallax, S. Wood, from the
Crag of England, may perhaps be referable to the species under description.

111. Discinisca Ctjmingii, Broderip, sp. (Plate XXVI. figs. 23-26.)

Orbimla Cumingii, Broderip, Proc. Zool. Soc. p. 124, 1833, and Traus. Zool. Soc. vol. i. p. 143,
pi. xxiii. fig. 1, 1835.

Orbicula strlgata, Broderip, Trans. Zool. Soc. vol. i. p. 143, pi. xxiii. fig. 1* 1833.

Orbicula Cuminyi and 0. strlgata, G. B. Sowerby, Tlics. Coach, vol. i. p. 3G6, pi. Ixxiii. figs. 6, 7, 1846.

Orbicula Cumingi, A. d'Orbigny, Voyage dans I'Ame'rique meridionals, vol. v. p. 677, 1847.

Orbicula Cumingi and 0. strlgata, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 276, 1852.

Dlscina Cumingi and 0. strlgata, E. Suess, Ueber die Wohnsitze der Bracliiopoden, Sitzungsb. k. Akad.
Wissensch. Wien, Bd. xxxvii. pp. 226-227, 1859.

Orbicula Cumingi, L. Reeve, Monogr. of Orbicula, Conch. Icon. pi. i. fig. 6, 1862 (Mr. Reeve considers
0. strlgata, Broderip, to be a synonym).

Dlscina Cumingi, Dall, Amer. Journ. of Couch, vol. vi. p. 77, 1870; Bull. ]\Ius. Comp. Zool. Harvard,
vol. iii. p. 42, 1871; and Proc. Acad. Nat. Sci. Philadelphia, p. 201, 1873.

Shell orbicular, or elongated oval, broadest anteriorly. Larger or ujiper valve
moderately thick, limpet-like ; vertex submarginal ; surface covered with numerous very
fine (sometimes interrupted) raised striae, which radiate from the vertex to the margin of
the valve ; surface crossed likewise by numerous, fine, concentric lines of growth.
Lower valve extremely thin, concave or flat, often taking the shape of the object upon
which it rests. About half the posterior portion of the valve is taken up by an elongated
oval or heart-shaped, slightly concave disk or area, perforated longitudinally along the
middle by an oval-shaped fissure which does not reach either to the posterior margin of
the shell or to the anterior extremity of the depressed smooth disk. The remainder of
the surface of the valve is very finely striated radiately and crossed by numerous con-

DE. T. DAVIDSOX 0^' EECEXT BEACHIOPODA. 203

centric linos of growth, tlic riblets increasing in number botli by bifurcation and by
the intcr2:)olation of sliorter ones. In the interior of the upper or lui'ger valve four
adductor muscular scars limit posteriorly and anteriorly a rather large sunken space,
which occupies, as it does in the lower valve, about half the posterior half of the valve.
The posterior adductor muscular impressions are transversely oval, oblic^uely situated at
a short distance from th(^ posterior margin of the shell, and separated by two very small
impressions or j^jrojections attributed to retractor muscles. The anterior, oval-shaped,
adductor scars are situate towards the middle of the bottom of the shell, and arc obliquely
placed and separated by a small longitudinal ridge, which extends for a short distance
along the sunken portion of the valve. In the interior of the extremely thin lower or
smaller valve its posterior half is, to a great extent, occupied by a heart-shaped disk with
convex lateral borders, but which does not quite reach to the jiosterior edge of the shell.
Along part of its centre a small, longitudinal, oval-shaped foramen is seen ; two small,
oblique, adductor scars occupy the posterior edge of the disk, and two others the anterior
part of the same disk, these last being separated by a longitudinal ridge which, com-
mencing to rise at the anterior extremity of the foramen, extends nearly to the front
margin of the shell. Shell-structure horny and calcareous. Colour light brownish yellow.
Length 9 lines, breadth 8 lines.

Hab. Cape St. Lucas to Panama, Central America ; dredged at Payta, St. Elena, Island
of Cafia, Guatemala, attached to the lower side of stones in sandy mud at low water,
and in some instances from a depth of from 6 to 8 fathoms (Cuming). Ecuador (d'Or-
bigny) ; Mazatlan, on various shells (Carpenter). Isle St. Joseph, Cayenne (Deplanche).

Obs. Exteriorly both in shape and striation the upper valve of Discinisca Cuni'mgii
much resembles that of Disclna striata ; but the smaller one, flat or concave in the
first, is convex in the latter. Again, the absence of the flattened disk in D. striata
and the difference in the shajie and position of the foraminal aperture are characters by
which the two forms may be easily distinguished.

In his monograph on Orhicula Mr. L. Peeve observes that "Mr. Broderip's 0. strigata,
which he did not describe along with 0. Cumingii in the ' Proceedings of the Zoological
Society,' but as an afterthought, when figuring the Orhiculce in the ' Transactions,' is a
less worn state of the species, in which there are faint rays and bands of colour. The
upper valve is calcareous and firm, of quite a different type from the horny species of
Chili and Peru. The habitats, Malacca and Philippine Islands, given with this species by
Mr. Sowerby, in addition to the above, are erroneous. He probably mistook specimens
of 0. Stella for it."

Broderip's figures of Orhicitla Cumingii and 0. strigata differ a good deal in shape; for
while the posterior margin of the first is I'ounded, that of the latter is strongly indented ;
but this may be accidental, lie likewise represents the mantle-fringe of horny setae in
his figure of Orbicula Cumingii ; they are very much shorter in this species than in
Discinisca atlantica.

Discinisca Cumingii varies a good deal in the elevation of its upper valve ; in some
specimens the apex is also almost marginal, while in others it is more or less distant
from the posterior margin.

204 DE. T. DAVIDSON OX KECE^^T BEACHIOPODA.

TJncei'tain Species.
112. DisciNiscA (?) ANTILLARUM, d'Orbigiiy. (Plate XXVI. figs. 31-31 a.)

Orbicula antillarum, d'Orbigny, Moll, cle Tlsle de Cuba dans le voyage ;\ Cuba de Ramon de la Sagra,
p. 368, pi. 28. figs. 34-36, 1853.

Discina antillarum, E. Suess, Ueber die Wohnsitze der Brachiopoden, SitzuBgsb. k. Akad. Wissensch.
Wien, Bd. xxxvii. p. 228, 1859.

Orbicula antillarum ?, L. Beeve, Conch. Icon., JMonogr. of Orbicula, pi. i. fig. 2, 1862.

Discinisca? antillarum, Dall, Report on the Bracli. obtained by the United States Coast-Survey Exp.,
Bull. Mus. Comp. Zool. Harvard, vol. iii. p. 42, 1871, and Proc. Acad. Nat. Sci. Philadelphia, p. 177,
July 1873.

Shell small, circular. Larger or upper valve limpet-like ; apex subcentral ; one third
of the valve from the apex is smooth, the remainder radiately striated. LoAver valve not
known. Shell-structure horny and calcareous. Colour light yellowish brown. Length
and breadth 2 lines.

Bah. Cuba, Martinique (d'Orbigny & Cuming).

Ohs. I have never seen a real type of this very small species (or young stage of some
other ?). D'Orbigny says, " Cette espece n'a que les bords marques de stries rayonnantes,
le reste est lisse; elle est mince, fragile, transparente et pourvue de lougcils tout autour.
Nous I'avons rencontree fixee sur un madrepore proveuant de I'ile de Cuba."

In his monograph on Orbicula Mr. L. Eeeve observes that " Mr. Cuming possesses
specimens of 0. antillarum, both from Cul)a and Martinique, in all of which the vertex
is inclined more posteriorly, while the shell is less regularly striated and less cancellated
than in the Eastern 0. stella ; but the shells are wonderfully alike in general aspect."
The specific claims of this so-termed species will require confirmation by the inspection
of additional Cuban specimens.

113. Discinisca stella, Gould. (Plate XXVI. figs. 27-30.)

Discina stella, Gould, ]\Iem. Boston Soc. Nat. Hist. vol. vii. p. 323 ; Otia Conch, p. 120, 1860.

Orbicula stella, L. Reeve, Conch. Icon., Monogr. of Orbicula, pi. i. fig. 1, 1862.

Discina stella, A. Adams, Ann. & ilag. Nat. Hist. 3rd ser. vol. ii. p. 100, 1863; Dall, Amer. Journal
of Conch, vol. vii. part 2, p. 76, 1871.

Discinisca stella, Dall, Report on the Brachiopoda obtained hy the United States Coast-Survey Exp.
in charge of L. F. de Pourtales, Bull. Mus. Comp. Zoul. Harvard, vol. iii. p. 41, 1871, and Proc. Acad.
Nat. Sci. Philadelphia, p. 201, 1873.

Discina stella, Davidson, Proc. Zool. Soc. April 1871, p. 311, pi. xxx. fig. 5, and Report on the
Brachiopoda of the Voyage of H. M.S. 'Challenger,' Zoology, vol. i. p. 64,1880; G. Dunker, Index
Moll, maris Japonici, p. 254, 1882.

Shell orbicular, about as broad as long. Upper valve conical and moderately elevated ;
vertex subcentral. Surface marked by numerous radiating striaj ; vertex alniost smooth
The attached or lower valve is remarkably thin, almost fiat or slightly concave, and
sometimes does not seem quite to reach the edge of the upper valve ; in the posterior
half of the valve a wide heart-shaped disk exists, with an elongated oval-shaped slit or
foramen for the passage of the peduncle. From the margins of this disk radiate fine

DE. T. DATIDSOX OX ]?ECEXT BRACHIOPODA. 205

raised strite with very wide interspaces. Colour light yellow. Length and hreadth
6i lines.

Sab. Singapore and Philippines (Cuming) ; China Seas (Stimpson, Wilkes, Gould) ;
Seto-Uchi (Akasi), 17 fathoms; Isu-Sima, 17 to :25 fathoms; Tahu-Sima, 20 fathoms,
on coral ; Japanese waters (Adams). Five upper valves were dredged by the ' Challenger'
Expedition at Station 190, lat. 8° 50' S., long. 130° 5' E. Tlic species was also dredged
by Capt. St. John in the Straits of Corea, attached to shells and associated with
Laqiieus pictus, lat. 33° 4' N., long. 129° 18' E.

Ohs. Although usually radiately finely striated, the strife were so faintly indicated in
some examples that have come under my notice that the shell appeared smooth, and in
that condition it was difficult to distinguish it from Dlscimsca (dluntica. In his Conch.
Icon., Monograph of Orbicnla, Lovell Ileeve states that " this species has a wide dis-
tribution in Eastern seas. On comparing authentic specimens received from Dr. Gould,
one of which is given at fig. ] h, pi. ii., collected in the China Sea by "VYilkes's exploring
expedition, I find them identical with specimens collected by Mr. Cuming, attached to
fragments of Pidlastra, Pinna, and 3Ialleus, at Singapore and at the Philippine Islands.
The sculpture varies in strength; on young specimens, as stated by Dr. Gould, the
radiating stria? are scarcely develoj^ed ; in older specimens, and especially specimens
that have had to contend with irregularities in their place of attachment, the sculpture
has a minutely-latticed character, like the grains of a thimble. The under valve is
thinly membranaceous, or thicker, concave or convex according to circumstances of
habitation ; and the position of the slit obviously varies with the position of the vertex
in tlie opposite valve. On a flat place of attacliment the shell is symmetrically orbicular,
and the vertex and subincumbent slit are nearly central, but when attached to a sloping
or declivitous substance the vertex is pressed to one side, and the slit of the under valve
follows the same direction."

Family LINGULID.E.

The recent species belonging to this family are representatives of the genus Lingula,
Bruguiere (1789), and of the genus or subgenus Glottidia, Dall (1870).

Genus LIXGULA.

1. Linyula anathia,\^s.xaa.Yck, 1819.

2. Mans, Swaiuson, 1823.

3. tumidula, Reeve, 1841.

4. Murphiana, King, 1859.

5. Lingula Reevii, Davidson, 1852.
G. exusta, Reeve, 1857.

7. Jaspidea, Adams, 1863.

8. Adamsi, Dall, 1873.

There are, besides these, three uncertain so-termed species — Lingula smaragcUna,
Adams, 1803; L. hirimdo, Reeve, 1859; audi, lepidula, Reeve, 1803. Hancock's L.
ajfinis I consider to be the true Lingula anaiina, the species Hancock figured as L. anatina
being really the L. Mnrplnana of King.

Up to the year 1870 the species now classed with Glottidia had been described as

206 DE. T. D.WIDSOX ON EECENT BRACHIOPODA.

Lingnlce, viz.: — Glottidia alhkla. Hinds, sp., ISio; Glottldia Falmeri, Dall, sp., 1870 ; and
Glottidia Ai(dcharti, Broderip, sp., 1883 (emend. Deshayes), of which the L. jryramldata
of Stimpson must be considered a synonym. A careful comparison of many specimens
of i. Aiidebarti, Broderip, and G. fyramidala, Stimpson, has convinced me that they
are one and the same species, and Broderip's name takes priority. The specific claims
of G. antillarum, Beeve, sp., 1861, and of G. ? semen, Broderip, sp., 1833, are still
uncertain.

114. LiNGULA ANATiNA, Bruguiere, sp. (Plate XXIX. figs. 1-8.)

Patella unguis, Linne, Syst. Nat. ed. xli. p. 1260, 1766.

Rostrum anatis, Vet'iyer, Rumphius, D'Amboiusclie Rariteitkaraer, t. xl. fig. 2, 1766; Seba, Moll.
vol. iii. t. xvi. fig. 4.

Mytilus Unyula, Solander, Cat. Museum, Portland^ no. 1718.

Pinna unguis sen lingua, Clicmuitz, Conch. Cab. x. p. 360, tab. clxsii. figs. 1G75-1677.

t Lepar seu Patella, "Rostrum anatis," Humphrey & Da Costa, Nat. Hist, of Shells, p. 3, pi. ii. fig. 2,
1770.

Patella unguis, Gmeliu, Linn. Syst. Nat. ed. xiii. p. 3710, 1789.

Lingula anatina, Bruguiere, Hist, des Vers, Encycl. Meth. pi. eel. figs. 1 a,b, c, 1789; Cuvier, Soc.
Philomat.ique de Paris, vol. i. p. Ill, pi. vii. figs. A, B, C, 1797 ; Cuvier, Memoires du Museum, vol. i.
p. 69, pi. vi. figs. 1-13, 1802.

Mytilus lingua, Dillwyn, Cat. of Recent Shells, p. 322. no. 47, 1817.

Lingula anatina, Lamarck, An. sans Vert. vol. vi. p. 258, 1819; Sowerby, Genera of Shells, 1822;
W. Swaiuson, Phil. Mag. vol. Ixiii. p. 403, 1823; Sowerby, A Cat. of Shells of the late Earl of Tauker-
ville, p. 28, 1825; Blaiuville, Mai. pi. Hi. fig. 3, 1825-27; Sander Rang, Man. de I'Hist. Nat. des
Mollusques, 1829; Deshayes, ed. An. sans Vert. vol. vii. p. 390. no. 1, 1866; Deshayes, ed. Eucyclop.
Meth., Vers. vol. ii. p. 364. no. 1, 1836; Anton, A^erzcichniss der Conchyl. p. 24. no. 911, 1839; Kiister,
ed. Chemnitz, Conch.-Cab. vol. vii. p. 12, pi. i. figs. 1, 2, 3, 1843.

Lingula Chemnitzii, Kiister, ed. Chemnitz, Conch.-Cab. vol. vii. p. 13, pi. i. figs. 4, 5, 6, 1843,

Lingula anatina, G. B. Sowerby, Thes. Conch., Monogr. of Lingula, i. p. 337, pi. Ixvii. figs. 1-10, 1846.

"i Lingula anatina, Vogt, Anatomic der Lingula anatina, pp. 1-16, pis. i., ii., 1845.

Lingula unalina, Davidson, Ann. & Mag. Nat. Hist. 2nd &er. vol. ix. p. 377, 1852; Brit. Foss.
Braeh., Introd. to vol. i. p. 134, 1853, and vol. v. p. 327, 1884; Article Brachiopoda, Brit. Encycl,
9th ed., 1876; Report on the Brachiopoda, Voyage of H. M.S. 'Challenger,' Zool. vol. i. p. 60, 1880; R,
Owen, Anatomy of Terebratulu and Lingnla, Davidson's Br. Foss. Braeh., Introduction to vol. i. chap, i.,
1853.

"> Lingida affinis, Hancock, Phil. Trans, vol. cxlviii. 2ud part, 1858,

Lingula hirtula, Gray, Coll. of Brit. INIus.

Lingula anatina, S. P. Woodward, A Manual of the MoUusca, p. 239, figs. 155-157, 1856 ; H. & A.
Adams, The Recent Genera of Mollusca, p. 585, pi. cxxxii. fig. 5, 1858; Semper, On Lingula, Zeit-
scbr. £. Wiss. Zool. vol. ii. p. 100, and vol. xiv. p. 424, 1861; E. Sucss, Ueber die Wohnsitze der
Brachiopoden, Sitzuugsb. k. Akad. Wissensch. Wien, Bd. xsxvii. p. 229, 1859 ; L. Reeve, Conch. Icon.,
Monogr. of Lingula, pi. ii. figs. 10, 11, 1859; Gratiolet, Anatomie de la Lingula anatina, Journ. de
Conch, vol. viii. 2nd ser. pis. vi.-ix., 1860 ; Dall, Amer. Journ. of Conch, vol. vi. p. 155, 1870, and Proc,
Acad. Nat. Sci. Philadelphia, p. 203, 1873 ; King, Ann. & Mag. Nat. Hist. 4th ser. vol. xii. pi. ii.,
1873; A. Zittel, Handb. der Pnlaontologie, p. 663, fig. 486, 1880; A. Crane, The Brachiopoda and
Polvzoa, Cassell's Nat. Hist. p. 203, 1881 ; G. Dunker, lude.K Moll, maris Japonici, p. 254, 1882; D, E.
Lischke, Japonische Meeres-Couch. Suppl. iv. p, 163, 1884.

DR. T. DAVIDSON ON EECENT BRACHIOPODA. 207

Shell oblong, elongated, sides nearly straight and subparallel. Valves very slightly
convex and nearly straight in front, attenuated at the posterior extremities ; almost
equal, slightly gaj)iug at the beaks, most convex along the middle, somewhat flattened
laterally ; dorsal valve a little shorter at the beaks than tlie ventral one. Texture
horny and calcareous ; surface smooth. Colour various shades of green up to l)right
emerald- green. Length 1 inch 10 lines, breadth 10 lines.

Hab. Indian Ocean and the Moluccas (Cuming), shore and low water; off Yeddo,
Japan (Adams). Dr. Willemoes-Suhm, of the ' Challenger ' Expedition, in a letter
published in Siebold and Kolliker's ' Zeitsclirift,' 187G, mentions finding on the beach
at Zamboanga, Philippines, a Lingula [L. aiiatiiia) in hundreds, and tliat he gave a
dollar for a hundred specimens. Three large bottles full were forwarded to me for
examination, collected by the ' Challenger ' Expedition in sand at low water at the same
place, on October 23, 1871, and February 1, 1875, These specimens, of all ages, from
4 lines in length up to 1 inch 7 lines, were of a most brilliant emerald-green colour.
Mr. L. Reeve states in his monograph on Lingula : — " Mr. Cuming happened to bo at
Manilla in 1836 after an unusually boisterous typhoon, when as many as twenty bushels
of this species were collected on the shore of the bay." It occurs no doubt in other
places. In the Zoological Department of the British Museum there are specimens from
Timor (Stokes's Coll.) and from the Eiji Islands (Hind's Coll.).

Obs. Cuvier, who was, I believe, the first to describe the animal of Ling a la in 17U7
and 1802, observes : — " Comme elles n'ont point de dents a leur charuiere, on ne pouvait
deviner, en les voyant isolees, qu'elles ctaicnt bivalves ; et Linnajus, qui n'en avoit vu
qu'une, I'avoit placee parmi les patelles sous le nom d' unguis, sous lequel elle parait
encore, quoique avec doute, dans I'edition de Gmelin, Rumphe, et apres lui Favanne
avoit pense que ce pouvait ctre le bouclier testace de quelque limace. Chemnitz ayant
u occasion d'en voii" les deux valves, jugea, je ne sais trop pourquois, qu'elle devoit
passer dans le genre des jambonneaux, et la nomma Finna unguis. Bruguiere est le
premier auteur systematique qui ait su que ces deux valves sont naturellement attachces
a un pedicule membraneux, comme celles des Terebratules et des Anatifes, et qui en ait
fait en consequence, dans les planches de I'Encyclopedie, un genre particulier, dont il
ne donne point de description, parceque son voyage et sa mort rempeeherent de conduire
jusque la son dictionnaire d'Helminthologie. Mais le citoyen Lamarck a adopti- et
caracterise ce genre."

No species of Brachiopoda has been more carefully studied by several of our besr con-
temporary zoologists. Owen described it in 1833, and again referred to it in his chapter
on the anatomy of Terebralula in the Introduction to- my work on British Fossil
Brachiopoda. In 1815 the same subject was well treated by Dr. C. Vogt, in his memoir
' Anatomie der lAngula anatina.'' In 1856 it was studied by Dr. S. P. Woodward, and
alluded to in his excellent manual of the Mollusca. In 1858 the anatomy of L. anatina
was admirably treated by Albany Hancock, in the memorable memoir " On the Organiza-
tion of the Brachiopoda," published in the 'Philosophical Transactions' of the Eoyal
Society, vol. cxlviii. 1858. This was followed in 1860 by Dr. Gratiolet's remarkable
memoir " Etudes anatomiques sur la Lingula anatina " in the ' Jovu-ual de Conchyliologie.'

SECOND SERIES. — ZOOLOGY, VOL. IV. 28

208 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Pi'ofessor Semper also published important observations on the animal of L'mcjula
nuathm in the ' Zeitschrift fiir wissenschaftliehe Zoologie,' Bd. xi. p. 100, 1862, and
in the " Ueisebericht " in the ' Zeitschrift fiir wissenschaftliehe Zoologie,' Bd. xiv. p. 424,
1864; and, lastly, Professor "W. King's instructive memoir "On some Characteristics of
Ziingula anatina," appeai'ed in the Ann. & Mag. Nat. Hist. 4th ser. vol. xii. 1873. To all
these works we shall again refer. The publications of Morse, Brooks, and others on the
animal of Glotlidia will also be alluded to under G. albida and G. Audeharti*.

Having had the advantage of being able to study more than five hundred specimens of
Lingula anatinu, four hundred of which were collected by the ' Challenger ' Expedition
in a single locality, I observed that when quite young and up to 9 lines in length the
shell was completely elongated, oval and rounded at its anterior margin ; the beaks
tapei'ing more than in the adult condition. As the shell grows the sides become
subparallel and its front line nearly as wide as the rest of the shell, and slightly rounded
in front, with a small rounded mesial rib, which, commencing at about two thirds of the
length of the valve, forms at the front line a small projecting angle. The horny portion
of the shell, especially round its margins, is so thin that as the animal dries it bends over
or shrinks, sometimes to a considerable extent. The colour also varies very much in
different specimens, being generally of a more vivid or intense green at and close to the
concentric lines of growth Avhich cover its surface. In some places also the green is
more bright than in others on all the specimens. It is of a brilliant emerald-green in the
Philippine examples, but more sap-green in the Manilla specimens. The valves are not
exactly the same ; the ventral valve is somewhat the larger, and it has an acutely
tapering beak, with a channel along its middle, to which the long fleshy peduncle is
attached ; the beak of the dorsal valve is, on the contrary, obtusely rounded and shorter,
with a narrow, flattened, horizontally striated area on its inner surface. In the interior
of the valves an elongated lozenge-shaped area is occupied chiefly by the muscular and
other impressions ; here where the calcareous element prevails the shell is thickest,
the remaining portion of the valves being more essentially horny.

The structure of the shell has been carefully investigated by Dr. Carpenter t, Di". Gra-
tiolet J, and M. S. Cloez §. Dr. Carpenter says: — "The structure of the shells of
Lingula and Orbiciila is peculiar. These shells are almost entirely composed of laminae
of horny matter, Avhich are perforated by minute tubuli, closely resembling those of
ivory in size and arrangement, and passing obliquely through the laminoe. Near the
margin of the shell, these tubuli may be seen lying nearly parallel to the surface."

Dr. Gratiolet states that : — " There exists in the shell o? Lingula two distinct elements,
that is to say a horny element and a testaceous one j|. They are found arranged

* [The more renoiit investigations of Dr. H. G. Beyer on the structure of Linrjula {Glottidia) i^nnmudata, Stimp-
son (' Studies from the Biological Lahoratorj- of Johns Hopkins University,' vol. iii. no. 5, March 1SS6), will bo
found summarized under Broderip's earlier described species Linr/tila (Glottidia) Audeharti, with which Dr. Davidson
found Liiir/ula pyramidata to be specifically identical. — A. C]

t " On the Microscopic Structure of Shells," Eeport Brit. Assoc. 1844, p. 18.

+ ' Journal de Conchyliologie,' 2« ser. vol. iv. 1800, p. 59. § Llnstitut, 1859, p. 240.

II [Dr. H. G. Beyer records the presence of a third element in one genus of the Lingulida?, i. c. an outer •' cuticle,"
differing in structure from the underlying so-called horny layers which alternate with the calcareous ones. See
anatomy of Glottidia Audeharti, p. 227. — A. C]

DE. T. DAVIDSON ON EECENT BRACHIOPODA.

20 &

Fis. 21.

Mu^iiified section
thickest portion
shell of Limjida ana
titta (uftcr(iratiolct).

of
of

A. Horny layer.

B. Calcareous layer, per-
forated hy canals.

in layers or thin laminae, which succeed each other alternately from the convex to the
concave surface of the valves after a superficial layer, Avhicli is horny. The layers do
not present anywhere the same thickness ; on the convex face of the
shell the thickness of the horny layer is the largest, on the inner or
visceral face the calcareous layers are the thickest ; those thick
testaceous layers are separated hy thin horny layers, the shell
being more semiti'anspareut where the horny layers prevail. The
structure of the lioruy layers is very simple ; they are transparent,
yellowish, passing into green in certain species, and appeared to me
formed of parallel fibres without any trace of perforations. The
structure of the calcareous layers recalls that of the Terebratulidse.
They are traversed by a multitude of microscopic canals, and are
likewise traversed by striti; of an extreme delicacy. The internal
surface of the valves is lined by a very dry and very thin mem-
brane, which can be detached without tearing away at the same time
portions of the very thin testaceous laminte. M. S. Cloez has
prepared an analysis of the test of Lingula, which has been
published in the ' Comptes E-endus de la Societe Philomatique ' of
Paris ; and this author remarks that the composition of the shell
resembles that which M. Chevreul has shown, in a work published
some years ago by Ilatchard, to exist in the scales of the Lepidostrees
and insects, and that the great proportion of phosphate of lime in
the shell of the living LinguJce deserves the attention of zoologists and geologists, and
gives a great interest to the results furnished by microscopic analysis."

Space unfortunately will not allow of my entering into details in connection Avitli the
anatomy of the animal of Lbujnla anatlna, which would require many elaborate illustra-
tions. I must therefore refer the student to the special works upon the subject abo^e
quoted.

Cuvier, in 1797, gives tlie first very brief account of the animal witli which we are
acquainted. He represents the two lobes of the mantle, one of which he has partly
bent backwards, so as to expose the spirally coiled labial appendages. He describes
also the alimentary canal, mouth, and anus ; and in 1802 he published a more elaborate
account of the animal accompanied by thirteen figures.

Hancock states, in his memoir on the " Organization of the Brachiopoda " (Phil. Trans.
E-oy. Soc. cxlviii. 1858, p. 794), that in Lingula " the body of the animal is depressed, and
occupies a much larger portion of the shell-cavity than it does in either the Terebratulidce
or BhyiichonelUdce. The pallial lobes are rather stout ; but the great sinuses are never-
theless distinctly seen through their membranes ; they are not united behind, as in
the articulated Braehiopods, but are free, and extend some distance from the body
all round the posterior or umbonal region. The body thus becomes well defined, the
lateral walls beino? at ri"-ht ambles to the dorsal and ventral. The two latter are verv

COO •

delicate, and so transparent that the viscera are quite apparent through them, tlie liver
and genitalia being the most conspicuous. The lateral parietes are strong and muscular,

28*

210 DR. T. DAVIDSON OX RECENT BRACHIOPODA.

and, having their edges attached to the valves, give a definite form to the enclosed
space, which is -wide, rounded in front, and tapering backwards.

" On turning hack the ventral pallial lobe the arms are observed occupying the greater
portion of the pallial chamber, which is about half the length of the shell. The mouth
is situated, as in the Terebratulidaj, in the brachial groove ; and on each side of it, a
little below, are the ovarian outlets, which penetrate the anterior wall of the body. On
the right side of the animal, l)etween the margins of the mantle, is placed the anal orifice,
which is A-ery distinct and easily detected.

" On removing the dorsal parietes in Liiigula, the alimentary tube is found to occupy
a central position as in the articulated tribes, the anterior portion being buried, as in
them, beneath the lobulated liver, which is rather bulky. On displacing the latter, the
heart is seen attached to the upper surface of the stomach, and the two dorsal genital
organs are entirely exposed, extending nearly the whole length of the perivisceral
chamber. At the sides and in front of these are the extremities of the muscles, and
behind are the convolutions of the intestine."

Elaborate descriptions of the various muscles and of their functions have been published
by Cuvier, Owen, Vogt, Hancock, Gratiolet, Semper, Woodward, Morse, Brooks, Beyer, and
others, each anatomist giving difl^crent names to the different muscles and interpreting
their functions differently. Much confusion consequently ensued. In 1873 Prof. W.
King devoted much time and care to an examination of the muscular system in Lingula
anatina * ; and as I had occasion to confirm his observations by personal investigations,
I cannot do better than reproduce some of the details given in his valuable memoir.

In the interior of both valves the muscvilar and visceral area forms a large lozenge-
shaped space, which, commencing close to the beak, extends to about two thirds of the
length of the shell and tapers most anteriorly, and is most elevated along the middle ;
this area constitutes tlie thickest part of the shell, where the calcareous element prevails,
and its colour is whitish, contrasting with the greenish horny aspect of the remainder
of the interior. This is also the most important compartment of the posterior half of
the shell-cavity, and is bounded by a highly muscular wall or parietal baud, b (fig. 22,
A, B), and contains the viscera and muscles. King proposes to name this division
the splanchnocosle, or visceral cavity, and adds : — "The anterior half of the pallial inter-
space is open all round (sides and front) except at its back, which is formed by the
anterior parietal. It encloses the arms or brachial appendages, and may therefore be
called the brachiocoele or brachial chamber. Its upper and under surfaces (dorsal and
ventral lobes of the pallium or mantle) are highly vascular.

"The sides of the splanchnoccele in its posterior half, as just stated, are rather strongly

incurved, giving rise to two lateral spaces I propose to give the name plenrocoeles

to these spaces, simply from their position as side chambers." The area within the
parietal, b, is occupied by the liver, genitalia, and shell-muscles. "There are five
pairs, and an odd one. Three pairs, Avoodcut, fig. 22, A, B {j, k, I), are lateral, having
their members limited to the sides of the shell. One pair is traiismecUcm (i), each

* Ann. & Mag. Nat. Hist, -ithser. vol. xii., 1873.

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

211

Fig. 22.

A.

B.

member passing across the middle to reverse sides of the shell. One pair {h) has its members

confined to nearly the central region. The odd muscle {(/) occupies the umboaal cavity.
Lateral muscles.— In. the dorsal valve one pair [j), which may be termed the anterior is

attached to the median plate, a member

passing from each of its sides* to the corre-
sponding one in the opposite valve." [This

median plate or rounded ridge is very pro-
minent in some specimens and species,

especially so in Lingiila Mtirphiana.'\ " The

second or outside pair [l] in the ventral valve

has each member passing from the outer

side of the central muscles to the same side

in the dorsal valve, close to the posterior

half of the ante-latero-parietal, and in the

widest part of the splanchnoccele. The third

or middle pair {k) springs from the ventral

valve between the central muscles, each

member passing to its corresponding side in

the oj^posite valve, increasing much in size

in the passage, and l^ecoming inserted in

front of, and inwardly to, the attachments of

the muscles belonging to the last pair."

These muscles leave deepish oval-shaped

scars in the interior surface of the valve, and
., are generally easily recognizable.

" Transmediaii muscles {i). — In the dorsal

valve both members of this pair are im-
planted in the widest part of the splanchno-
ccele, one on the inner side of, and immediately adjacent to, the termination of the
laterals k and I. Passing backward, each member crosses diagonally to the reverse side
of the ventral valve ; but while one preserves its unity, and terminates by inserting
itself near the middle of the left post-latero-parietal, the other is divided in its passage,
a division becoming inserted near the posterior, and another near the anterior, end of the
opposite and corresponding parietal. The divided member embraces the undivided one."
The lateral muscles do not always leave well-marked impressions in the interior of the
valves ; they are only seen occasionally on very well-preserved specimens. " It may be
assumed," continues Prof. King, " that the central and umbonal mviscles ((/, li) elFect the
direct closing and opening of the shell, and that the laterals {j, k, I) enable the valves to
move forward or backward on each other : but with respect to the transmedians (/), it is
difficult to conceive otherwise than that they allow the similar extremities (the rostral) of
the valves to turn from each other to the right, or the left, on an axis subccutrally
sitnated — that is, between the anterior attachments of these muscles a little behind the
medio-transverse line of the dorsal valve."

L!)ii/>da anatina.

A. Interior of tho ventral or pedicle valve.

B. Interior of the dorsal valve (after King) : fj, umbo-

nal muscular impressions (open valves) ; h, central
muscles (close valves) ; i, transmedian or sliding
muscles : 6, parietal band : ./, Ic, 1, lateral muscles
(./, anteriors ; I; middles ; 1. outsiders), enabling
the valves to move forward and backward on each
other.

212

DE. T. DAVIDSON ON RECENT BEACHIOPODA.

23.

It was long a question under discussion whether the animal could really displace its

valves sideways when about to open the shell ; l)ut this has been actually observed by

Profs. Semper, Morse, and Brooks, who saw the animal

perform the operation. They mention tliat it is never

done by jerks, as the valves are first always pushed to

one side several times and back again on each other, at

the same time opening gradually and in the transverse

direction till they rest opposite to one another and widely

apart. Those who have not seen the animal in life, they

observe, and did not believe in the possibility of the valves

crossing each other with a slight ol)liquity, would not

consent to the appropxiation of any of the muscles to that

purpose, and consequently attributed to all the lateral

muscles the simple function of keeping the valves in

opposite position or holding them adjusted. Prof. King

states, in the paper already quoted, that "the umboual

muscle," {g), "is in no way fettered by the pedicle, or any

other part. The shell is not only edentulous, but its

hinge-margins are widely and totally separated from each

other. The beaks have their margins persistently apart,

even when the umbonal muscle is mostrigid. The post-latero-

parietals are highly muscular, necessarily permitting an

unusual play of motion between the valves at their pos-
terior extremity. The ordinary muscles {h,j, h, I), princi-
pally, are limited to the middle third of the valves All

these structural peculiarities are reciprocally related, and

they are strictly consistent with the office herein ascribed

to the transmedian muscles."

" The mantle-lobes forming the dorsal (upper) and ven-
tral (under) surfaces of the chamber are well characterized
by the vascular system. Both lobes are traversed by a pair
of primary vessels that run foi'ward from the anterior

parietal, a member from each of its sides : gradually approximating in their progress,
without becoming united, they terminate, the dorsal pair at about a quarter of an inch,
and the ventral pair at about twice this distance, from the margins of the chambers.
Prom their inner side numerous secondary vessels strike inwardly, Avith a backward

curve, and meet in the middle line of the valves Although the setal band, as it

may be termed, runs along the pallial margins in their entire extent, the course of the
seta3 in the ventral valve is interrupted in one j)art — that is, in the region of the pedicle :
there is no interruption in the opposite part of the dorsal valve."

The brachial organs of Lincjula anatina are described by Mr. Hancock (at p. 810
of the memoir already quoted) to be " strong and fleshy, and rise from the back of the
pallial chamber in the usual manner. They are entirely without calcareous support, even at

Lingula anatina.

Diagram, after Hancock, showing the
muscular system. The letters
indicate the muscles as in fig. 22,
A and B.

A, ventral valve ; B, dorsal valve ; j),
peduncle ; a, alimentary canal ;
z, anus.

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 213

their orij^in ; and form two spiral coils, with six or seven turns eat-h, directed inwards
and upwards. The arms are very thick at the base, taper more suddenly than in the
articulated species, and terminate in fine points. On making a transverse section they
are found to differ in organization from those of Uhjnchonellu, to which, externally, they
bear the strongest resemblance. Instead of one, as in that genus, there are two great
brachial canals, which may be denominated respectively the anterior and posterior. The
former is the equivalent of the great canal in the other Brachiopods, and, like it,
terminates at the side of the oesophagus in a blind sac. It is j)retty regularly
cylindrical, with the walls excessively thick, being composed, for the most part, of a white
cartilage-like su.bstance, which is most developed towards the side opposite the cirri.
These latter organs are supported upon a semicartilaginous grooved ridge, which is very
similar to that in Wuldhehnia, and in like manner supplied with a very ample brachial
fold. Muscular fibres are also provided for the movements of these parts ; but the
fibres, though similarly arranged, arc not so extensively developed. This canal is lined
with a muscular stratum, the fibres of which run in a transverse direction in the vicinity
of the brachial fold ; elsewhere they arc longitudinal or slightly diagonal.

" The posterior canal is much flattened, and stretches along the inner surface of the arm,
extending from the base of the cirri halfway round it. The canal has the appearance
of being formed by a process of the pallial membrane similar to that which extends along
the lateral portions of the loop in Waldheimia. The posterior canals of the two arms
terminate at the sides of the oesopliagus behind the anterior canals, and are separated
from each other by a considerable space, which is divided on the median line by a delicate,
membranous septum. The two chambers thus formed communicate with the peri-
visceral cavity by two smaU oval orifices placed one on each side of the septum ; these
orifices open into the cavity close behind the oesophagus, and directly above the transverse

fold of the anterior wall of the body It seems clear enough that the arms of

Lingula have the power of extension in a greater or less degree (p. 811) The

anterior canals in Lingula will perform the same ofiice as the great canals do in other
Brachiopods ; that is, they wiU give firmness to the parts, so that the cirri and the brachial
fold may be brought into play. When the arms are retracted the walls of these canals,
which it will be remembered are closed tubes, will relax a little to relieve themselves
from the pressure of the contained fluid ; when they are extended the walls will contract
to maintain the required pressure. Thus the cirri and brachial fold will be under the
control of their proper muscles, however much or little the arms may be extended.

" The alimentary tube in Lingula (p. 815, loc. cit.) presents two or three interesting
modifications. The mouth is perfectly similar to that of Waldheimia, and the oesophagus,
which is somewhat elongated, is at first depressed ; but on emerging backwards from
between the anterior occlnsors becomes compressed. The stomach is sliort, being almost
lenticular, and the transverse dorsal ridge is much produced. In front it is slightly convex,
where it receives the oesophagus ; behind it is a little produced, and an inconspicuous
constriction marks the commencement of the intestine, which running backwards, buried
beneath the lobules of the liver, and resting above the posterior adjuster muscles, gradually
descends towards the ventral lobe, immediatelv in front of the divaricator muscle. This

214 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

straight portion of tlie intestine corresponds to the entire intestine of the articulated
Brachiopods, and it thus appears that in Llngida, as well as in them, the first inflection
of the intestinal tube is towards the ventral surface. From thence the tube bends to
the left, and turning forwards and upwards, forms two large loops at the posterior
portion of the perivisceral chamber ; it then advances along the right side, and, dipping
under the dorsal extremities of the adjuster muscles and the pseudo-heart, opens through a
nipple-like anus situated at the right side of the body between the margins of the mantle.
The anal orifice is ample, and is very easily distinguished ; it is placed considerably nearer

to the dorsal than the ventral surface The liver is composed of ramified caeca, and

is of a greenish colour, as in all the Brachiopods " (p. 816).

Hancock then describes the reproductive organs, which, he states, are really developed
between the two layers composing the ilio-parietal bands. He adds that the reddish-yellow
marks are the ovaries, and that it would be fair to conclude that Lingula, at least, is andro-
gynous ; and if the red matter in connection with the genitalia in the articulated
Brachiopoda should jirove to be the same as the dendritic organ of the former, then in
them also the sexes are combined (p. 819, loc. cit.) *.

The ova of Lingula anatina were figured in Prof. Owen's memoir on the anatomy of the
Terehratulce appended to the Introduction to my monograph of British Fossil Brachiopoda.

The peduncle in Lingula anatina attains a very great length, and has been minutely
described by the zoologists already named. Drs. Vogt and Gratiolet state that it is com-
posed of two essential parts — (1) a horny envelope, (2) a central muscular mass. The
external envelope is very thick, resisting, and constitutes a tube open at both ends. The
opening of the lower end is gaping, that of the other end, perforated in the centre of the
inflated portion, is very narrow, and affords passage to small muscular bundles. It is
remarkable how very much this peduncle shrinks and shrivels up when in the dried
condition. In an abstract of Prof. Morse's paper on Japanese LlngulcB and shell-mounds,
published in the ' American Journal of Science and Arts,' vol. xv. 1878, it is stated that his
studies of L'mgtda. have brought out many points new to science. The discovery of auditory
capsules in the class of Brachiopods is one of the most impoi-tant. These organs he
determined in a species of Lingula, and their position and general appearance recall the
auditory capsules as figured by Claparede in certain tubicolous Annelids f. He has also
cleared up many of the obscure points in regard to the circulation, and is prepared to
maintain the absence of anything like a pulsatory organ, the circulation being entirely
due to ciliary action. Prof. Morse also described some of the habits of Lingula. "While
partially buried in the sand the anterior border of the pallial membranes contract in
such a way as to leave three large oval openings, one in the centre and one on each
side. The bristles, which are quite long in this region of the animal, are arranged
in such a way as to continue these openings into funnels, and entangle the mucus which
escapes from the animal ; these funnels have firm walls. A continual current is seen

* [The recent investigations of Dr. H. G. Beyer fully confirm Hancock's views as to the hermaphroditism of
Lingula {GloUkUa) pyramidata. See Note p. 238. — A. C]

t Dr. W. K. Brooks states at p. 63 of his paper on "The Development of Lmgida " (Results of the Chesapeake
Zoological Laboratory, 1S7S), that these octocysts do not exhibit any annelidan characteristics: they are precisely
such structures as are found in most of the Mollusca.

DR. T. DAVIDSON ON EECENT BKACHIOPODA. 215

passing down the side-funnels and escaping- by the central one. They bury themselves
very quickly in sand, and the peduncle agglutinates a sand-tube. They attach themselves
by means of this tube to the bottom of dishes in which they are conlined. Prof. Morse
exhibited living specimens of a Lingula (probably anatbia) which he had brought from
Japan in a small glass jar. The water had only been changed twice during the last six
months, and yet no specimen had died. This illustrated more fully the vitality o^ TAugula
than the experiments he had made on the North Carolina Z/>;Y/«/rt [Glottklia) pyramidata
several years since.

Lingula anatina at Manilla and elsewhere are made use of as articles of food ; and
Prof. Morse tells me he has eaten them. Some examples attributed to Lingula anatina
described by Adams and C. E. Lischke from Japanese waters are green ; others, which
are partly yellowish brown and green near the frontal margin, cannot be speciilcally
separated from L. anatina. I compared several examples sent to me by Lischke, and
found them to be identical.

115. Lingula affinis, Hancock. (Plate XXIX. figs. 9, 10.)

Under this name A. Hancock describes and figures the animal of a Lingula (Phil.
Trans. Roy. Soc. vol. cxlviii. 1858), which I believe to be in reality the true Lingula
anatina, and I am also convinced that the species he describes and figures by the name
anatina is the Lingula Ilurphiana. His descriptions show that the animal in those two
forms is sufiiciently different to be referred to distinct species. Mr. Hancock, soon
after the publication of his admirable memoir, sent a specimen of his L. affinis for my
inspection. I found it to be of a bright green colour, and apparently agreeing both in
shape and appearance with L. anatina; while, on the contrary, the specimen he had referred
to L. anatina was much wider in proportion to its length, of a yellow coppery tint, and
exactly resembled specimens oi Lingula Mnrphiana in my collection. The point cannot,
however, be definitely settled until the animal of L. 3Ln'phiana has been again examined.

116. Lingula Murphiana, King, MS. (Plate XXIX. fig. 11.)

Lingula Murphiana, King, MS., Mus. Cumiug; L. Reeve, Mon. of Lingula, Conch. Icon. pi. i. fig. 3,
1859; Dall, Amor. Journ. Conch, vol. vi. p. 155, 1870.

Shell large, squarish oblong, longer than Avide, sides almost parallel, slightly curved
inwards towards the middle of their length. Anterior edge gently rounded, with angular
projection in the middle; beaks attenuated, that of the ventral valve pointed and the
longest. Valves about equally convex, with a flatness commencing close to the beaks
and extending to the front and on each side sloping to the lateral edges. Colour
coppery red, with bands of different shades of green and brown. In the interior of the
valves the muscular area is white, the remainder of the surface light and dark green.
Shell-structure horny and calcareous. Length of shell 2 inches G lines, breadtb. 1 inch
1 line ; length of peduncle G^ inches.

Hah. Moreton Bay, Australia (Strange).

Obs. In his monograph on Lingula, Mr. L. Reeve observes, " Whether this should

SECOND SEBIES. — ZOOLOGY, VOL. IV. 29

216 DR. T. DAVIDSON ON EECENT BRACHIOPODA,

be reo'arded as an Australian form of Lingula anatina or as a distinct species, it is
certain that the differences are obvious and constant. The late Capt. Phillip King, who
was an excellent conchologist (witness his paper on the collections of his exploring
voyage in the ' Zoological Journal'), Avas struck by the peculiarities of this Lingula, and
sent specimens home to Mr. Cuming with the above name. More have been collected
bv Mr. Strange in nearly the same locality, and all are distinguished from L. anatina,
collected abundantly by Mr. Cuming in tlie Bay of Manilla, by a more square outline
and a peculiarly coppery-red tone of colour."

The shell of L. Murpliiana seems to attain to larger dimensions than that of L. anatina,
and the structvire of the animal would differ, if I am correct iu ray belief that Albany
Hancock described that of L. M^irphiana by the name of anatina (in the Trans, of the
Royal Society, vol. cxlviii. pi. Ixiv. and ])1. Ixv. figs. 1 and 2, 1858). The shell is wider in
comparison to its length, thicker, and differs in colour. The anatomy of LiuQula having
been noted under L. anatina need not be here repeated.

117. Lingula tumibula, Eeeve. (Plate XXVIII. figs. 14, 15.)

Lingula tuinichila, L. Reeve, Proe. Zool. Soc. 1841, part ix. p. 100.

Linijala compressa, L. Reeve, Proc. Zool. Soc. 1841, part ix. p. 100.

Lingula tumidula, G. B. Sowerby, Thes. Conch., Monogr. of Lingula, vol. i. p. 393, pi. Ixvii. fig. 7, 1846.

Lingula tumida, Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 377, 1852.

Lingula tumidula and L. compressa, L. Reeve, Concli. Icon., Monogr. oi Lingula, pi. i. fig. 2, 1859;
E. Sness, Ueber die Wohnsitze der Bracliiopoden, Sitzungsb. k. Akad. Wissenscli. Wien, Bd. xxxvii.
p. 47, 1859 ; Dall, Proe. Acad. Nat. Sci. Philadelphia, p. 204, 1873.

Shell large, horny, thin, squarely oblong, slightly attenuated at and towards the beaks ;
umbones indistinct ; sides subparallcl, nearly straight in front, with a small angular
projection in the middle ; valves closed on each side. Colour coppery brown or reddish
olive, sometimes bright green near the posterior margin. Surface smooth, marked with
concentric lines of growth. Length 2 inches 2 lines, l)readth 1 inch 5 lines.

Hab. Island of Masbate, Philippines (Cuming) ; Moreton Bay, Australia (Strange).

Obs. This is the largest and finest recent species of the genus with which we are at
present acquainted, and is broader in proportion than any other known recent form. As
stated by L. Reeve in his description of the species, the variety compressa, which he
regarded in 184-1 as a distinct species, was only a badly preserved specimen resulting
from the mode of drying, which had been collected by Mr. Cuming in sandy mud and
low water at Palanas, Isle of Masbate, one of the Philippines. The Lingula from Japanese
waters, referred by Mr. A. Adams and myself to L. timiidula, was afterwards found to
differ from Reeve's species, and subsequently received from Mr. W. H. Dall the specific
name of L. Adamsi (see p. 218 of this Monograph, PI. XXVIII. fig. 19). Lingula tumi-
dula seems to be nearly allied to Lingula Ilurphiana, which is longer in proportion to its
breadth. I have not seen good interiors of the valves of L. tumidula.

118. Lingula hians, Swainson. (Plate XXIX. figs. 12, 13.)

Lingula hians, Swainson, The Phil. Mag. and Journal, vol. Ixii. p. 401, 1823.
? Lingula anatoni, KUster, ed. Chemnitz, Conch. -Cab. p. 14, pi. i. figs. 7-9, 1843.

DE. T. DAVID8()N ON EECENT BRACHIOPODA. 217

Lingula Mans, G. B. Sowerby, Thes. Concb., Monogr. of Limjula, p. 338, pi. Ixvii. fig. 1, 18 IG;
Davidson, Ami. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 377, 18.")2 ; L. llccve. Conch. Icon., Mouogr. of
Lingula, pi. 2. fig. \2u-b, 1859; E. Suess, Ueber die Wohnsitzc dcr Bracbiopoden, Sitzungsb. k. Akad.
■Wissenscli. Wien, Bd. xxxvii. p. 229, 1859; Gratiolct, l^tudes anatoniiqucs de la Lingula anatina, Journ.
de Concb. 2° ser. vol. iv. 18G0 ; Dall, Amcr. Journ. of Conch, vol. vi. p. 15G, 1871, and Proc. Acad.
Nat. Sci. Philadelphia, p. 203, 1873.

Shell thin, lengthened oblong, rather broadest anteriorly and tapering a little
posteriorly ; beak of ventral valve extending considerably beyond that of the dorsal valve,
and much attenuated and sharply pointed at its extremity ; lateral edges of the valves
slightly curved inwards. Colour pale green, surface marked with numerous concentric
lines ; colour pale yellowish green, vivid sometimes at or near the front ; peduncle more
than twice the length of shell. Length of shell 1 inch 10 lines, breadth 9 lines.

Hah. China Seas.

Ohs. This species seems to vary a good deal in shape, some specimens being broader
anteriorly, others posteriorly, judging from the iigures given by Reeve. Swainson
says, in his paper on the species, " The belief that two distinct shells had been hitherto
confounded under the same name of L. anatina, first struck me when examining the
magnificent collection of Lord Tankerville, and the observations I have since made and
the numerous specimens I have examined, have both tended to strengthen this belief.
I have therefore here assigned to each its sj)ccific character."

Sowerby says that L. Mans is distinguished from L. anatina " by being mucb thinner,
and of a more delicate green colour, it is also slightly and gradually attenuated towards
the base ; it only gapes at the extremities when the valves are separated from the animal
and dried." L. Reeve, on the contrary, states, in his monograph on Lingula, " the gaping
of this species does not appear to depend upon the drying of the shell ; it always dries
into a gaping attitude, which is not the case with other species."

I am, however, of opinion that the drying has a great deal to do with the gajnng
observed in the dried specimens. The shell is very horny and thin, and when such is
tlie case the shell gets much out of shape when drying. Mr. W. 11. Dall considers
L. Antoni, Ki'ister, to be a synomyn of L. Mans. Prof. E. Suess admits L. Antoni
among the distinct species of the genus. Never having seen a specimen of Kiister's
species, I am unable to express any opinion with respect to its specific claims. It seems
like a variety of i. anatina. Some parts of the anatomy of this sjjccies have been
described and illustrated by Dr. P. Gratiolet in the ' Journal de Conchyliologie ' for 1860.

119. LiNauLA EXUSTA, Reeve. (Plate XXVIII. figs. 20-21 a.)

Lingula exusta, L. Reeve, Conch. Icon., Monogr. oi Lingula, pi. ii. fig. 9, 1859 ; Dall, Proc. Acad.
Nat. Sci. Philadelphia, p. 203, 1873.

Shell oblong, much longer than wide, a little broader anteriorly ; sides almost sub-
parallel, slightly curved inwards near the middle of their length ; front line very gently
cu.rved, with a projecting angle in the middle. Valves convex, beaks obtusely angular,
surface smooth, shining, darkish coppery yellow-brown, especially towards the lateral and

29*

218 DR. T. DAVIDSON ON EECENT BRACHIOPOD A..

frontal margius. Peduucle longer than the length of the shell, dark in colour. Length
of shell 1 inch 7 lines, breadth 8 lines.

Hab. Moreton Bay, Australia (Strange).

To his description of this shell Mr. Lovell Reeve adds : — " If L. MurpUiana be an
Australian form of L. anatina, this might be regarded as the representative in the same
locality of L. Jdans. Both species exhibit a peculiar coppery redness, heightened in
this to a dark, shining, swarthy tone of colour." I, however, believe both L. anatina
and L. Murphiaua to be distinct species, as Hancock found the animal to be different.

Obs. I have seen a number of specimens of this shell, and all presented the same
shape and marked dark colour.

120. LiNGULA JASPIDEA, Adams. (Plate XXVIII. figs. 23, 24 a.)

Linijula juspidea, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 101, 1863.
LinguJa Dumortieri ?, Nyst, Davidson, Proc. Zool. Soc. 1871, p. 310, pi. xxx. fig. 3.
Lingula jaspidea, Dall, Proc. Acad. Nat. Sci. Pliiladelphia, p. 177, July 1873.
Linijula Dumortieri, G. Dunker, Index Moll, maris Japonic!, p. 254, 1882.
Linijula jaspidea, C. E. Lischke, Jajjanische Meeres-Coucliylien, Suppl. iv. p. 163, 1884.

Shell elongated oval, broadest near the beaks, tapering gently to near the front margin,
which is gently rounded outwardly. Beaks obtusely angular ; valves very moderately
convex, surface marked with slight, almost microscopic, and close-set longitudinal lines,
the valves being likewise crossed by concentric lines of growth. Colour tan or warm
light yellowish brown. Peduncle about four times the length of the valve. Length of
shell 1 inch 4 lines, breadth 8 lines, depth 3.

Hab. Mososeki, Japan, 7 fathoms, mud (Adams) ; Japanese Avaters (Belcher).

Obs. Adams briefly described, but did not figure, his species ; this was done some
years later by myself from Adams's type in the Proceedings of the Zool. Soc. for 1871.
Since that period I have obtained a much larger and better specimen from Sir E.
Belcher, dredged by him in Japanese waters. The specimen was in s]3irits, and its
peduncle showed its full length.

In 1871 I referred Adams's species to the Lingula Dumortieri of Nyst (Coquilles et
Polypes Eossiles de la Belgique, p. 837, pi. xxxiv. fig. 4, 1843), and I believe I did not err
in so doing ; but as some malacologists seem uncertain about the matter, I have thought
it preferable, at any rate until a large number of specimens have been collected
and compared, to retain the name given to the shell by Mr. Adams.

Dr. Gwyn Jeffreys wrote me in 1871, that the Japanese shell could not be dis-
tinguished in any way from that of Lingula Dumortieri from the Coralline Crag of
Suffolk and of Belgium.

121. Lingula Adamsi, Dall. (Plate XXVIII. fig. 19.)

Lingula tumidula, A. Adams (not of Reeve), Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 100, 1863 ;
Davidson (not of Reeve), Proc. Zool. Soc. 1871, p. 310, pi. xxx. fig. 1, 1871.
Lingula Adamsi, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 202, 1873.
Lingula lepidula, G. Dunker (not of Reeve), Index Moll, maris Japonici, p. 251, 1882.

DR. T. DAVIDSON ON RECENT BRACHIOPODA. 219

Shell squarely oblong long'itudinally, slightly broader anteriorly. Sides almost
parallel, nearly straight in front, obtusely tapering at its posterior margin. A^alves
flattened or very gently convex. Surface marked with very numerous close and minute,
equidistant, slightly projecting, concentric lines or ridges of growth. Colour light
yellow or brownish yellow, with a reddish-broAvn spot near the beak. Peduncle about
twice the length of the valve. Interior of the valve not known. Length of shell 1 inch
5 lines, breadth 10 lines.

Hah. Tsaulian harbour, Korean Archipelago, 7 fathoms, mud (Adams) ; dredged by
Capt. Weston near the shore, off the island of Eormosa.

Ohs. Few specimens of this species have been hitherto brought to England. A. Adams,
in 1863, identified it with Reeve's L. tumidula, but did not figure the shell. He sent it
to me to be figured in 1871, and I fell into the same mistake and referred it to Reeve's
species. In 1873 ]Mr. Dall gave it the name of L. Adamsi, which I now readily adopt, as
I never felt satisfied that the shell had been correctly identified. Heine, in his
' Expedition in die See'n von China, Japan und Ochotsk,' 1858, Bd. i. p. 137, alludes
to a Linyula from Oosima (N.E. of Eormosa) which may possibly be L. Adamsi, but
I have not been able to consult his work.

122. LiNGULA Reevii, Davidson. (Plate XXVIII. figs. 17, 18f^)

Lingula ovalis, L. Reeve, On Lingula, Proc. Zool. Soc. part ix. 1811, p. 100; G. B. Sowerby, Thes.
Conch, p. 393, pi. b;vii. fig. 8, 184G ; Davidson, Ann. & Mag. Nat. Hist. 2nd scr. vol. ix. p. 377, 1853;
L. Reeve, Conch. Icon., Monogr. oi Linyula, pi. i. fig. 1, 1859; Dall, Amer. Journ. of Coach, vol. vi.
p. 15G, 1870, and Proc. Acad. Nat. Sci. Philadelphia, p. 203, 1873.

Linyula reevii, Davidson, Report on the Brachiopoda, Voyage of II. M.S. ' Challenger,' Zoology,
vol. i. p. 62, 1880.

Shell oblong oval, broadest about the middle, longer than wide, rather narrow; sides
very gently curved outwardly, front rounded ; posterior edge obtusely acuminated ; valves
moderately convex. Surface smooth, blue-green or emerald and verdgiris-green,
especially along the middle ; peduncle thick, much longer than the length of the shell.
Length of shell 1 inch 5 lines, breadth 8 lines.

Ilab. Sandwich Islands (Pease).

Ohs. This beautiful and brilliantly coloured shell was described in 181.1 by Mr. Lovell
Reeve under the name of Liiiffula ovalis ; but, as I have stated in my report on the Brachio-
poda of the ' Challenger ' Expedition and elsewhere, this name cannot be retained for tlie
recent shell, because it had been applied by Sowerby as far back as 1813 to a well-known
Kimmeridge-clay species (Min. Con. tab. 19. fig. 14-, April 1813). I therefore, in 1880,
proposed that the name of the recent form should be altered to that of L. Heevii. In
181-1, as stated by Reeve, Mr. Cuming knew nothing of the haljitat of the shell under
description ; but since then a number of specimens of this species have been received
from Honolulu, one of the Sandwich Islands.

220 DR. T. DAVIDSON ON EECENT BEACHIOPODA.

Uncertain Species.

123. LiNGULA SMARAGDiNA, A. Adams. (Plate XXVIII. fig. 25.)

Lingula smaragdina, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 101, 1863 ; Davidson,
Proc. Zool. See. 1871, p. 310, pi. xxx. fig. 2 ; Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 203, 1873.

Shell oblong oval, longer than wide ; sides subparallel ; front margin almost straight,
obtusely angiilar posteriorly at the beaks ; valves very moderately convex, smooth, bright
green, whitish in the middle and near the beaks ; length of peduncle not known. Length
of shell 10 lines, breadth 4 lines, some specimens somewhat exceeding those dimensions.

Hah. Yobuko, 10 fathoms, mud, Japan, also in China seas (Adams).

Ohs. This species (?) was described, but not figured, by Adams in 1863. In 1871 I
figured the shell from Mr. Adams's type ; he adds to his description " a bright green
species, found also in the China seas, and most nearly resembling L. hiriindo, Eeeve." I
have seen so little of this species (?) that I cannot feel certain as to its specific claims. It
bears much resemblance to some young examples of Lingida anatina.

124. LiNGTJLA HiRUNDO, Reeve. (Plate XXVIII. fig. 22.)

Lingula, Idrundo, L. Reeve, Conch. Icon., Monogr. of Lingula, pi. ii. fig. 7, 1859 ; Dall, Proc. Acad.
Nat. Sci. Philadelphia, p. 203, 1873.

" Shell oblong-square, thin, greenish, posteriorly abruptly attenuated ; umbones rather
sharp. Length 11, breadth 4^ lines.

" Hah. Port Curtis, North-east Australia (Stutchbury.)

" Several specimens of this little semitransparent species were collected by Mr.
Stutchbury at the above-named locality."

Ohs. As I know nothing more respecting the specific claims of this so-termed species, I
can only reproduce the statements Mr. L. Peeve has published with respect to his
species.

125. Lingula lepidtjla, A. Adams. (Plate XXVIII. fig. 16.)

Lingida lepidnla, A. Adams, Ann. & Mag. Nat. Hist. 3rd ser. vol. xi. p. 101, 18G3; Davidson, Proc.
Zool. Soc. 1871, p. 311, pi. xxx. fig. 4; Lischke, Japauische Mceres-Concbylien, Snppl. iv. p. 1G3, 1884.

Shell small, oval, longer than wide, tapering a good deal at the beaks; sides and
front gently rounded. Colour yellowish, slightly tinted with red. Length 4 lines,
breadth 2 lines.

Ifab. Seto-Uchi (Akasi), Japan, 10 fathoms, mvid (Adams).

Ohs. Mr. Adams did not figure his species, but he sent mc his type in 1871, and I
figured it in the Proc. of the Zool. Soc. for that year. Mr. Adams adds to his description
" that it is a species as small as i. semen and shaped like L. ovalis." 1 have seen so little
of this so-termed species that I am unable to advocate its specific claims, but I am more
inclined to consider it the young of some other form. Some young specimens of
Jj. anatina from the Philippine Islands much resemble it in shape.

DE. T. DAVIDSON ON RECENT BRACHIOPODA. 221

Genus GLOTTIDIA, DaU, 1870.
Glottidia, DaU, American Journal of Conchology, vol. vi. jj. 157, 1870.

Type Glottidia albida. Hinds, sp.

" Sliell linguiforni, elongate, pedunculated ; general characters as in Lingula.
Neural [dorsal] valve provided internally with two sharp, narrow, incurved laminae, di-
verging from the beak, and extending about one third the length of the shell ; ante-
rior extremities of the laminae about midway between the mesial line and the margin.
Hsemal [ventral] valve with a mesial septum of about the same length, extending forward
from the beak. Anterior adductor impressions rounded, separated by a faint mesial
ridge, faintly impressed. Scar of the post-adductor close in the cavity of the beak,
rounded. No other evident scars. Shell smooth, perforate or imj)erforate.

" This genus apj^ears to take the place in America of the genus Lingula, which has its
home in the Australian and Indo-Pacific seas." {Ball.)

126. Glottidia albida, Hinds, sp. (Plate XXVIII. figs. 2-4.)

Lingula albida, Hinds, Zoology of H.M.S. ' Sulphur,' p. 298, pi. xix. fig. 4, 1845 ; G. B. Sowerby,
Thes. Conch, p. 393, pi. \\\\\. fig. 6, 1846 ; Davidson, Ann. & Mag. Nat. Hist. 2nd ser. vol. ix. p. 377,
1852; L. Reeve, Couch. Icon., Mouogr. oi Lingula, pi. i. fig. 4, 1859 ; E. Sucss, Ueber die Wohnsitze
der Brachiopodeu, Sitzungsb. k. Akad. Wissensch. Wien, Bd. xxxvii. p. 230, 1859.

Glottidia albida, Dall, Amcr. Joum. of Couch, vol. \\. p. 157, pi. 8. figs. 1-C, 1870 ; Proc. Acad. Nat.
Sci. Philadelphia, p. 204, 1873 ; Dall, Seieutific Results of the Exploration of Alaska, 1877 ; Davidson,
Report on the Brachiopoda, Voyage of H.M.S. ' Challenger,' Zoology, vol. i. p. 2fi, 1880.

Shell narrow, elongated oval, linguiform, tapering at the beak, sides almost subparallel,
very slightly curved in front ; rather rolled, creamy white, smooth, shining, marked
with concentric lines of growth, rather flat, especially along the middle, or from near the
extremity of the beak to the front, with a slight mesial rounded ridge along the middle.
Peduncle stout, short, transversely wrinkled, exhibiting two longitudinal edges Avith a
groove between them. In the interior of the longest or ventral valve the beak is pointed,
with a small triangular-shaped thickening, grooved along the middle ; from under it a
narrow mesial septum of very small elevation extends to about one third of the length
of the valve. Posterior occlusor or central muscles obliquely oval, situated near the
middle of the valve, and separated by a faint mesial ridge. In the interior of the dorsa.
or smaller valve two diverging narrow septa of very small elevation extend to a little
beyond a third of the length of the valve ; at about the middle of the valve two oblique
oval-shaped central muscular sears, or posterior occlusors, are separated by a long faintly
marked mesial ridge; shell-structure calcareous and horny. Length of shell 1 inch
2 lines, breadth G lines.

Hah. Magdalena Bay, California, in 7 fathoms, among sandy mud (Ilinds) ; San
Diego Bay, California (Hemphill). Dredged by Dr.W. Newcomb off Santa Barl^ara Island.
California, in 28 fathoms (Dall) ; Monterey (Stearns); Catalina Island (Cooper), in 10 to
60 fathoms ; muddy bottom, rarely on tidal flats in mud at lowest water (Dall).

Obs. This species was briefly described by Pl. B. Hinds in 1845, and .since then more

222 DE. T. DAVIDSON ON RECENT BEACHIOPODA.

fully by Sowerby, Reeve, and Dall. In 1870 it was selected by Ball as the type of
bis genus GlottkUa. When describing G. albkla, he states, at p. 158 of his ' Revision
of the Terebratulidaj and Lingulidee,' " This species differs from the typical species of
LiiiffulidiB, in the diverging lamella? which support the post-parietals, in the form
of the anterior adductor scars, and in its colour. A microscopical examination of the
shell gave the following results : — There were no punctures visible with a good light and
a power of 900 diameters. The substance of the shell was shown by a cross section to
be composed of translucent horny laminae, nearly parallel with one another and separated
by layers of white amorphous calcareous matter, which looked much like powdered
sugar. There were no tubuli visible after the most careful search ; the horny layers
presented faint indications of a partially fibrous structure, but nothing of the kind ex-
tended to the calcareous layers. A section of the lamina much resembled the end of a
T-rail, with one flange taken ofi' and obliquely inclined. The anterior part of the shell
contained less calcareous matter than that nearer the beaks, and the margin seemed
entirely horny. The number of horny layers amounted to eight or ten, in the thickest
part of the shell. They were not uniform in thickness, but were thinner than the amor-
phous calcareous layers."

Only the central muscular scars are well defined in the interior of the valves.

Mr. Dall observes, in his report on the Brachiopoda of Alaska in 1877, that GlottkUa
albkla " has not been found to the northward of Monterey, though it may yet turn up
somewhere. It is usually not over three inches in length, peduncle included. Like
other species of Lingulida?, when young, it is free, and burrows in the mud. Adult
specimens, with favorable opportunity, often fasten themselves to a pebble or fragment
of shell by the distal extremity of the peduncle. This has been also observed with
GlottkUa miramklata, Stm., in Morida, by Mr. P. B. Meek, though that species had been
supposed to be always free. It would seem probable, from information communicated
to me by Mr. Meek, that these creatures are of rapid growth, and live at most but one or
two seasons."

127. Glottidia Palmeri, Dall. (Plate XXVIII. figs. 5, G«.)

Glottidia {? albida, var.) Palmeri, Dall, American Journal of Conchology, vol. vii. p. 77, 1871.
GlottkUa Palmeri, Dall, Proc. Acad. Nat. Sci. Philadelphia, 1873, p. 20L; Davidsou, Brit. Foss.
Brack, vol. iv. p. 3G2, figs. 1-4, 1881.

Shell narrow, elongated, beaks sharply acuminated, sides subparallel, or very slightly
curved ; front line nearly straight. Valves very moderately convex, with two obscurely
rounded ridges, commencing at the extremity of the beaks, and deviating until they reach
the anterior rounded corners of the front of the valves, and with another similar ridge along
the median line ; lateral portions of the valves sloping from the deviating ridges to the
lateral edges of the shell. Colour creamy white, smooth, glossy, with obscure impressed
lines and concentric ones of growth. Shell-structure calcareous and horny. In the
interior of the dorsal and ventral valves the septa and muscular impressions are similar

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 223

to those already described under Glottidia albkla. Length of sliell 1 inch 8 lines, breadth
7 lines ; length of peduncle over 1 inches.

Mah. At the head of the Gulf of California, on the Lower Californian shore, opposite
the mouth of the Colorado River; on sandy shelly mud at low-water mark. Ten
specimens of the animal were collected by Dr. Edward Palmer, who spent many hours
groping in the mud for the small number of specimens above recorded.

Ohs. This is the largest species of recent Glottidia hitherto discovered. It was care-
fully described by Dall in 1871 as a variety (^) of G. albida, but in 1873 he considered it a
distinct species, and I feel inclined to agree with him in his last determination. G. Palmeri
is, as stated by Dall, a much more elongated shell than G. albida, and narrowei*. The
beaks arc more acute, the internal laminae are closer together, and less widely divergent.
The peduncle, ho adds, is much longer, and the brown colour, so conspicuous on the
exterior, is not found in G. albida, which also has a much more prominent median
carina, and a more solid shell, which does not gape. It is most desirable tliat the animal
of this fine species should be anatomically examined. When describing Liagula (or Glot-
tidia) Lesueuri from the Silurian rocks of Brittany and Budleigh Salterton, I remarked
that it had been questioned by M. de Tromelin whether that species was a true Lingiila.
It is characterized by the presence of a median septum on the interior of the ventral
valve, and two diverging ones on the dorsal one, and in external shape and character
so closely resembles Glottidia Falmerl that were this recent form fossilized, it would be
hard to distinguish it from the Lower Silurian li. Lesueuri.

128. CtLOTtidia Audebarti*, Broderip, sp. (Plate XXVIII. figs. 7-11.)

Lhiffula Audcbardi, Broderip, Traus. Zool. Soc. vol. i. p. 143, p]. xxiii. fig. 14, 1835 ; Owen, Trans.
Zool. Soc. vol. i. p. 157, 1835 ; Kiistcr, ed. Chemnitz, Concli.-Cab. pi. i. fig. 11, 1843; G. B. Sowerby,
Concli. Icon. i. p. 338, ^\. Ixvii. fig. 5, 184(3; Anton, Verzeich. d. Conch, p. 24, 1839; Davidson, Ann.
& Mag. Nat. Hist. 2nd scr. vol. ix. p. 377, 1852; L. Reeve, Conch. Icon., Monogr. of L'lnyulu, pi. i. fig. 5,
1859; E. Suess, Ucber die Wolmsitze der Brachiojioden, Sitzungsb. k. Akad. Wisseuscli. Wien, Bd.
xxxvii. p. 230, 1859.

Lhigula pyrumidatu, Stimpson, Amer. Jouru. Sci. & Arts, vol. xxxix. p. 444, 1860.

Lingula Audebarti, Deshayes, in Lamarck, An. sans Vert. ed. 1836 ; E. Morse, Amer. Naturalist,
vol. iv. p. 314, figs. 76-78, 1870 ; Amer. Jouru. Sci. & Arts, vol. 1. figs. 1, 2, 3, 1870 ; Ou the Systematic
Position of the Brachiopoda, Boston Soc. Nat. Hist. vol. xv., 1873.

Glottidia Audebarti and G. jjyranddata, Dall, Amer. Journ. Concli. vol. clviii., 1870 ; Proc. Acad. Nat.
Sci. of Philadelphia, p. 204, 1873.

Lingida pyramidatu, Davidson, " Brachiopoda," Encyclopiedia Britannica, ix. cd. p. 188, 1876 ;
Brooks, On the Development of Lingula, Scientific Results, Chesapeake Zool. Laboratory, p. 35, 1878.

Lingula {Glottidia) pyramidatu, Davidson, Brit. Poss. Brach. vol. v. pp. 328, 329, 1884; H. G. Beyer,
Studies from the Biol. Laboratoiy, Johns Hopkins University, vol. iii. no. 5, March 1886.

Shell oblong, thin, narrow, broadest posteriorly, beaks tapering to an acutely angular
termination. At about one third of its length the margins gradually taper poste-
riorly, front margin nearly straight. Valves moderately convex, smooth, marked with

* The word printed by Broderip '' Audehanlii " was corrected by Deshayes, in his edition of Lamarck, iuto
Audibarti, the species being named iu honour of M. J. d'Audebart de Ferussac.

SECOND SERIES. — ZOOLOGY, VOL. IV. 30

224 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

concentric lines of growth ; texture horny, with a slight deposit of lime in the thickest
part of the shell, very finely perforated. Colour cream-white, with sometimes transverse
lines or bands of green, especially on its anterior half and edge. In the interior of the
ventral or longest valve two thin septa or ridges of small elevation diverge from the beak
to about one third of the length of the valve, and in the dorsal valve a single median
similar ridge or septum extends from under the beak to about one third of the length of
the valve ; muscular scars as in Glotlklia albida. The peduncle is very long, and secretes
a mucus to which grains of sand adhere, especially for some distance along its posterior
extremity. Length of shell 1 inch 1 line, breadth 6 lines.

Mab. Island of Punam, Bay of Guayaquil, at about half-tide, on an extensive bottom of
hard coarse sand, at from four to six inches below the surface (Cuming and Broderip) ;
United States, New'berne to Port Royal ; coasts of North and South Carolina (Dall) ; Port
Wool (Brooks). Mr. Dall informs me by letter, 29 Jan., 1885, that he has received Glot-
tidla ivjramidata from Mr. Hemphill, South Plorida Keys, where the shell grows larger
and slightly thicker than the more northern specimens, but is otherwise identical, and
that it becomes attached when adult to beds of shell or pebbles.

Ohs. An attentive comparison of many specimens of G. Audebarti, Broderip, and
G.pyramidata, Stimpson, has convinced me that they are the same species. Broderip's
name must consequently hold priority, and that of Stimpson be placed among the
synonyms. Glottidla Audeharti is w^ell distinguished by its shape from G. albida, Hinds.
In ' Science,' vol. iii. p. 325, 1884, Mr. W. H. Dall says that the Glottidia (?) antillarum.
Reeve, described from the West Indies, may be identical with it.

Glottidia Audebartl varies a good deal in shape ; and Broderip * observes : — " The
rounded anterior edge of this shell is green, and tbe transverse lines of that colour are
produced by the progressive increase of the shell, which is smooth and parchment-like.
In all the dried specimens the thin anterior edge is contracted into a square form, so as
to produce a resemblance to a very square-toed shoe ; but in its natural state this edge is
rounded. A general contraction, moreover, gives the dried shells a narrower and more
ventricose character than they really possess ; and the remains of the cilia (setae) give to
their anterior edges a bearded appearance."

The anatomy and embryology of this well-defined species have been studied with great
care by Professors Owen t, E- S. Morse %, and W. K. Brooks §. As it will not,
however, be possible in this monograph to reproduce all the important details they have
published upon the subject, we must limit ourselves to giving a few extracts from their
works, and refer the reader for more ample details to their respective memoirs upon
the subject.

In an abstract of his paper on " The Brachiopoda, a Division of the Annelida "

* Trans. Zool. Soc. vol. i. p. 144, 1S35. t Ibid. p. 157.

X American Naturalist, vol. iv. 1870; Amer. Journ. Sei. >fe Arts, vol. 1., 1870; and Boston Soc. Nat. Hist,
vol. XV., 1873.

§ Chesapeake Zool. Lab. Scientific Results, 1878. [Sec also licycr, " A Study of the Structure of Lhit/ida ( Glottidia)
pyramidata, Stimp., Dall." Studies Biol. Labor. Johns Hopkins University, Baltimore, vol. iii. no. 5, March 1886. —
A. C]

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

225

S. Morse is stated to liave found
shoal at

Fis. 24.

Glottidia 2>yramidata, from
life (after Morse).

(Amer. Journ. Sci. and Arts, July 1870), Prof. E.
Glottidia {jnjramidata) Andel)arti "in a sand
low-water mark, buried just below the surface of the sand.
The peduncle was six times the length of the shell, and
was encased in a sand-tube, differing in no respect from the
sand-tubes of neighbouring annelids. In many instances the
peduncle was broken in sifting them from the sand, yet the injury
was quickly repaired, and another sand-case was formed. He
observed that the animal had the power of moving over tlie
sand by the sliding motion of the two valves, using at the same
time the fringes of setae, which swung promptly back and
forth like a galley of oars, leaving a peculiar track in the sand.
In the motion of the setoe he noticed tlie impulse commencing
from behind, and running forward. Within the mantle he
found a series of rows of prominent lamella?, in which the blood
rapidly circulated, thus confirming the correctness of Vogt's
observations. These lamellae were contractile, however. The
peduncle was hollow, and the blood could be seen coursing
through its channel. It was distinctly and regularly con-
stricted or ringed, and presented a remarkably worm-like appearance. It had layers of
circular and longitudinal muscular fibre, and coiled itself in numerous folds or unwound
at full length. It was contractile also, and would quickly jerk the body beneath the
sand. But the most startling observation in connection with this interesting animal was
the fact that its blood was red. This was strongly marked in the gills and various rami-
fications of the mantle and in the pedvincle. At times the peduncle would become con-
gested, and then a deep rose blush was markedly distinct."

Prof. Owen states, in his observations on the anatomy oi Lingula Andebardli (p. 157), that
"the structure of this species corresponds in all essential particulars with tliat of Lingula
anatina as given by Cuvier. The differences appear first in the length of the cilia, Avhich
in the present species are three times longer than in Lingula anatina. The subdivisions
of the branchial vessels project from the inner surface of the mantle, in linear series similar
in tlieir direction to those of Lingula anatina ; but the lines are not continuous ; thev are
composed of distinct and separate folds of the mantle, of a minute size, along the con-
vexity of each of which a single vascular loop is extended without giving off lateral
ramulets, the whole structure affording a beautiful examj^le of the first stage in the com-
position of a complex lamellated gill. All the glandular masses communicating with the
alimentary canal bear the green colour characteristic of the liver, especially that central
one surrounding the stomach, which Cuvier has marked as the salivary gland of i. ana-
tina. "With respect to L. Audebardii, I shall only add, tliat the distal end of its pedicle
is dilated and rounded, and in the small specimen dissected did not present any appear-
ance of having been attached to a foreign substance Lingida, living more com-
monly near the surface, and sometimes where it would be left exposed by tlie retreating
tide were it not buried in the sand of the shore, must meet with a greater variety and

30*

226 DR. T. DAVIDSON ON EECENT BRACHIOPODA.

abundance of animal nutriment than can be found in those abysses in which Terehratula
is destined to reside. Hence, its powers of prehension are greatei', and Cuvier suspects
it may even enjoy a species of locomotion from the sujierior length of its peduncle. The
organization of its mouth and stomach indicates, however, that it is confined to food of
a minute description; but its convoluted intestine shows a capacity for extracting a
quantity of nutriment proportioned to its superior activity and the extent of its soft parts.
A more complex and obvious respiratory apparatus was therefore indispensable, and it is
not surprising that the earlier observers failed to detect a corresponding organisation in
genera destined to a more limited sphere of action."

Prof. W. K. Brooks has studied vrith great care the development of Olottidia
Audeharti ; and my only regret is that it is not possible here to transcribe all his
admirable observations. He begins by remarking thai " it has been known since about
the year 1860 that some of the hingeless Brachiopoda pass through a free-swimming
larval state. Fritz Miiller has figured and briefly described this stage of development
of an unknown Brachiopod from the coast of Brazil, and Mr. Crady has given a brief
description from memory of the swimming larva oi Lingula.'" Prof. Brooks states that he
obtained the larva o^ Lingula pyramidata [^=Glottidia Audeharti] in the vicinity of Fort
Wool during the summer, in considerable abundance, that he had succeeded in tracing its
development from a very early stage to the time when most of the adult characters
appeared, and that his observations not only show that Mr. Crady's fragmentary
account is correct in every particular, but also give us a very thorough acquaintance
with the embryo. "The free-swimming embryos of Lingula pijramidata were met
with in abundance at Port Wool, from about the middle of July to the middle of
August ; and as the youngest stages were met wdth in the early part of this period, while
only the older larvte were found at the end, it is probable that the breeding-season is
short. No adults were found until the end of July, and the reproductive oi'gans did not
then present any indications of functional activity, and although a number of individuals
were kej)t in an aquarium for several weeks, no eggs were laid, and I was unable to
obtain the early stages of development. The larva is enclosed between two orbicular
flattened valves, which are not articulated to each other, but are free round the entire
circumference. The dark-coloured, somewhat opaque, flask-shaped digestive organs
occupy the centre of the cavity of the shell, and are in contact above and below
with the integument which lines the valves. Around the digestive organs is
a body-cavity bounded externally hy the integument, which is continuous with the
mouth above and below, and is bent downward at right angles to the valves to form the
body- walls. On the sides of, and behind, and in front of the body, there is a capacious
mantle-chamber which is open around the entire circumference. The mouth opens in
the centre of a broad, flat, nearly circular disc or lophophore, around the margin of which
are the ciliated tentacles. The plane of the lophophore is not at right angles to the
long axis of the body, but inclined so as to be nearly parallel to it. The tips of
the tentacles may be extended beyond the edges of the valves, and thus form a
swimming-apparatus, somewhat like the velum of a mollusk, by the aid of which the
larva floats in the water or rises slowly to the surface." (See PI. XXX. figs. 7-11.)

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 227

" The changes undergone by the larva during development are gradual, and do not
involve any marked metamorphosis. ... In tlie figures, that valve of the shell which is
uppermost, is to become the movable valve of the adult : that wliich conchologists
have agreed to call the dorsal valve ; while the peduncle is to be attached to the ojiposite
valve, which is accordingly ventral. The nearly straight margin of the shell is that from
which the peduncle is subsequently to project, and therefore indicates the posterior end
of the body, while the opposite rounded margin is anterior." Prof. Brooks then proceeds
to explain the changes in the form of the larva, and adds : — " Before I pass to the de-
scription of the internal organization of the larva, I wish to call attention briefly to
the fact that the recent and fossil shells of various species of Crania, Discina, Lhigula,
Lingulella, Oholus, and other hingeless Brachiopoda, furnish a series of adult forms repre-
senting all the changes through which tlie outline of the shell of Lingula pyramidata
j)asses during its development."

Prof. Brooks then describes the digestive organs, the body-cavity or perivisceral
chamber, the blood, the mantle and integument, the pallial sinuses, the muscles, the
nervous system and sense-organs, the peduncle, the lophophore and tentacles, and con-
cludes with an elaborate discussion of the bearing of the development of Lingula upon
the systematic position of the Brachiopoda. Indeed, the whole memoir is replete with
original and valuable details and suggestions, which have materially added to our
knowledge on many difficult and important questions*.

* [An important memoir was i^ublished by Dr. H. G. Boyer " On the Structure of Lingula pyramulata ( = Glottidia
Andeharti) in vol. iii. no. 5, March 1880, of the ' Studies from the Biological Laboratory of Johns Hopkins University,
Baltimore.'

Dr. Beyer considers the shell in this species to be composed of three layers, an outer periostracum or cuticle, " a
simple homogeneous and comparatively thiu layer or membrane. . . . probably a changed original larval ectoderm
or in some way produced by it." This cuticle covers the valves and the peduncle, becoming thickened and corrugated
at the point of attachment of the peduncle to the animal. Beneath this cuticle a large number of peculiar rounded
corpuscles are seen imbedded in the shell substance, sometimes in linear series, but generally scattered irregularly, or
aggregated in clusters. " Immediately adjacent to the cuticle and this layer of homogeneous round corpuscles, we
find a rather broad layer of horny substance." This varies in thickness according to the age and size of the
animal. Closely adjoining this broad horny layer a very thin calcareous layer occurs, and this alternation of horny and
calcareous layers continues through the shell. The horny layers, Dr. Beyer believes, partake of the nature of a sup-
porting substance, and " represent the homologies of the vertical septa found in the substance of the shells in
testicardine (articulated) genera. The calcareous layers probably are the result of a secretion on the part of the
former, or that of a calcareous degeneration of the ectodermal cells of that part of the mantle and body-wall wliich
is next the shell."

The dorsal and ventral body-walls are closely adherent to and covered by the valves of the sheU, while the
remaining parts are comparatively free. The mantle is a fold of the body- wall itself. " The peduncle may properly
be looked upon as a worm-like backward jjrolongation of the body-wall and its cavity. The structural elements of
the body-wall, mantle and peduncle, are, first, an outer layer of ectodermal epithelium : secondly, a middle layer of
supporting tissue, variously modified according to situation ; and thirdy, an inner layer of lining or peritoneal
epithelium."

Immediately beneath the ectodermal covering the calcareous plates are situated, more particularly distributed over
the inner leaflet of the mantle and the lateral body-walls. The supporting tissue, in its ordinary aspect, is a homo-
geneous layer of tissue either entirely structureless, or presenting a very faintly longitudinally striated appearance.

All the so-called mesenteric bands are smiply bridges of a substance hitherto regarded as muscular, which also

228 Dll. T. DAVIDSON ON EECENT BEACHIOPODA.

Uncertain Species.
129. Glottidia (?) ANTiLLARTJM, Eeeve, sp. (Plate XXVIII. fig. 13.)

Lingula antillarum, L. Eeeve, CoBch. Icon., Monogr. oi Lingula, pi. ii. fig. 8, 1861.
? Glottidia antiUamm, Dall, Proc. Acad. Nat. Sci. Philadelphia, p. 204, 1873.

Shell elongated ovate, broadest posteriorly, tapering at the beak, pinched in anteriorly
at the sides, and almost straight in front. Valves very slightly convex and flattened ;
surface smooth, marked only by concentric lines of growth, light yellowish anteriorly,
tinged with blue-green towards the umbones. Length of shell 8, breadth 3^ lines.
Length of the peduncle not known.

Hah. Martinique, dredged at a depth of sixteen fathoms (Cuming).

Obs. This is a very uncertain species, and may be a young specimen of some other form.
Mr. L. Reeve states that he has seen only one specimen, which appears distinct, and whose

permeates the mantle-leaflets. But Dr. Be3-er considers these fibres as nothing more nor less than supporting fibres,
"passing in various directions, but having for their purpose the fixation of the cavities through which thcj- extend."

The peritoneal ejnthelium " consists of flattened polygonal cells, with small, round, central nuclei ; these cells are
joined together edgewise, and form a very thin and delicate membrane, which lines the walls of the perivisceral
chamber, the mantle sinuses, and blood-laeunes, covers all the viscera and mesenteric bands, and gives rise to blood-
vasoular spaces and channels within the body-cavity."

" All the muscles in Lingula are composed of long parallel fibres, and belong to the variety of smooth muscle-
fibres." The structures described by Hancock as ' parietal muscles,' and by Gratiolet as ' muscles haussieres,' as
well as the muscles on the arms and the peduncle, Beyer regards not as muscles, but rather " as a mesenchymatoua
supporting substance possessing a certain amount of elasticity, but lacking the contractibiUty proper to muscular
tissue only."

He was unable to detect any central propelling organ of the vascular system, and confirms the views held by
Shipley, Shulgin, Semper, and Morse as to the absence of a heart. He detected the presence of three diflerent kinds of
corpuscles floating in the circulating fluid, in addition to those connected with the structure of the shell ; the
blood-corpuscles proper, small round granular corpuscles, recurring chiefly within the mantle-sinuses and their
branches. These he was led to regard " as young ova which sooner or later become transformed into fuUy developed
ones," and peculiar, spindle-shaped, or oblong ovoid, striated bodies called spermatophorcs by Hancock, and young
Lingido! by Gratiolet.

Dr. Beyer divides the digestive apparatus of Lhvjida into three parts, viz., " The mouth and oesophagus, the
stomach and livcr-lobulcs, and the intestinal canal proper. . . . The apparent great strength of the tissues surrounding
the mouth and the prominences in the wall itself seem to imply a certain power for grinding the most solid food-
particles before they pass on into the oesophagus through a valve-like structure permeated with supporting fibres. . . .
The opening of the anus seems to be valve-like, running for a short distance within the supporting layer of the body-
wall before opening to the exterior."

The author adheres to the number and division of tlie nervous ganglia as given by Hancock in Waldhcimia
austndis. " There are in Linr/uJa,'' he says (p. 250), " five distinct nervous ganglia connected with the circum-
cesophageal commissure. . . . The great central suboesophageal, the two ventro-lateral, and the two dorso-latcral or
8upra-oesophageal ganglia" (the smallest of all).

" The description of the genital apparatus of ZjXf/j(fo may be divided into two parts, namely: — 1. That of the
genital glands, the organs producing the ova and spermatozoa respectively ; and 2. That of the oviducts or segmental
organs (Morse), which conduct (he spermatozoa and ova into the pallial chamber, and thence into the sea-water. . . .
The description of the generative glands in Wcddheimia austrcdis, a Testicardine Brachiopod given by Hancoclc, is in

DR. T. DAVIDSON OX EECENT BRACHIOPODA. 229

habitat is peculiar. Mr. Dall places it with two ? ? in his genus Glottidia ; but we have
no direct evidence that it belongs to that genus ; and in a letter to me, dated 29th Jan.,
1885, that writer says, "we have recently received Glottidia ptjramidata from the
Florida Keys, where it grows larger, and with a slightly more thickened shell, than
the more northern specimens, hut is otherwise identical ; and there can be no doubt
that it is identical with the Lhigula {Olottidia) originally described from Cuba, which
long antedates Stimpson's name." It will, however, be better, until the matter is finallv
determined, to leave it among the uncertain species and under its present name.

130. Glottidia (?) semen, Broderip, sp. (Plate XXVIII. fig. 12.)

Lingula semen, Broderip, Trans. Zool. Soc. vol. i. p. 141,, pi. xxiii. fig. 17, 1835; G. B. Sowerby,
Thes. Conch, p. 338^ pi. Ixvii. fig. 11, 1846; A. d'Orbigny, Voyage dans I'Amerique Meridionale, vol. v.
p. 071, 181.7 ; Davidson, Ann. & Mag. Nat. Hist. 2ud ser. vol. ix., May 18.12; L. Reeve, Conch. Icon.,

almost perfect accord with what we have found with regard to the genital glands in the Ecardine Brachiopod Lhv-
ffida." He notes the exception that the genital hands contained within the mantle-sinuses are attached to the outer
leaflet of the mantle instead of the inner, " and have no genital artery, as is the case in Waldhei mia " (p. 25-5).
It was only after considerable hesitation that Dr. Beyer was forced by the weight of evidence " to believe in the

fact that, so far, at least, as Linr/iila is concerned, the sexes are united within the same individual Hancock's

views arc still correct," he states, " so far as the genital ridges within the mantle-sinuses are concerned. "Within
these, according to our interpretation, both ova and spermatozoa develop side by side : it is, however, different within
the perivisceral chamber. Here the ova are confined principally to the mesenteric bands and their reflected portions
— in other words, occupy a more central position with relation to the animal — while the spermatophorcs occupy the
peripheral walls of the visceral chamber, in fact, are almost exclusively developed from the peritoneal epithelium
(covering in many layers, and much modified) the lateral body-wall, and to a slight extent also the dorsal and
ventral.

"While, then, in our opinion, Litujula is an hermaphrodite animal, it is nevertheless rare to find both ova and
spermatozoa present in equal proportions, and equally developed in the same individual. In those individuals in
which, for instance, the male elements largely preponderate fully developed ova are sometimes very few, and may
even be entirely confined to the mantle-sinuses, so that on a superficial examination they might be entirely over-
looked. A more careful examination of an entire series of sections, however, will invariably result in finding both
male and female organs of generation within the same individual.

" As already mentioned, the principal seat of development of the spermatophorcs is the lateral body-wall. This
arrangement seems to be in perfect harmony with the close apposition in some individuals of the cup-shaped internal

extremity of the segmental organs to the lateral body-walls, which, so far, has remained unexplained We

would therefore consider them as movable organs intended to take up spermatozoa or ova, and carry them into the
mantle-chamber at certain intervals ; and in accordance with this double function the relative position of their internal
openings changes ; at one time, it will bo found snugly apphed to the lateral body-walls, and then spermatophorcs
may be seen within the oviducts ; at another, their ciliated inner extremity will point directly backward towards the
most posterior portion of the visceral chamber, into which fully developed ova usuidly drop, and under these circum-
stances ova may be detected within the oviducts. Having never seen either ova or spermatophores within the same
oviduct, it is not to be supposed that fructification takes place inside the animal, but rather that this occurs in the
mantle-chamber or in the sea- water. . . . AVe think that there can now hardly bo any doubt as to the ova springing
directly from the cells composing the peritoneal lining membrane. . . . The development of the spermatophores also
takes place from peritoneal epitheUum." See PL XXX. figs. 12, 1:3, 14 of this Monograph, where some of
Dr. Beyer's illustrations are reproduced. — A. C]

230

DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Moncr. of Linyula, pi. ii.' fig. 6, 1859 ; E. Suess, Ueber die Wohnsitze der Brachiopoden^ Sitzungsb.
k. Akad. Wissenscli. Wien, Bd. xxxvii. p. 230, 1859.

Glottidia? semen, Dall, Amer. Journ. of Conch, vol. vi. p. 159, 1870; Proc. Acad. Nat. Sci.
Philadelphia, p. 20-i, 1873.

Shell small, ovate, oblong, broadest posteriorly, beak acuminated, sides subparallel,
front nearly straight, or very gently rounded. Valves slightly convex, flattened, smooth
and polished, rather thick. Length 5 lines, breadth 2J lines.

Kah. Dredged off the Isle of Plata, West Columbia, in a fine coral sand, from a depth
of seventeen fathoms (Cuming).

Ohs. I have seen only one specimen of this so-termed species. The type is in the
British Museum, and was described by Broderip, Trans. Zool. Soc. vol. i. p. 144, 1835. He
says, " It may be a young individual ; but the shell is so much firmer than it usually is
in Linyula (so firm, indeed, as not to have contracted at all in drying) that I cannot but
look on it as an undescribed species. In size and appearance it bears a near resemblance
to a melon-seed." It has all the appearance of a young Glottidia, but must remain an
uncertain species until further material is obtained.

Classification of the Hecent Brachiopoda.
ARTHROPOMATA, Owen

Subfamily TerebraUdino

Subfamily Terebratcllinm

Subfamily Mcyerlince . . .
1st Family
TEEEBKATTJLiDiE. \ Subfamily Mmjasinw . . .

Subfamily Kraussudnai .

Subfamily Argiopina>

Subfamily not yet determined

J

2nd Family Thecidiid^

3rd Family Ehynchonellid^

= CLISTENTERATA, King.

I. Geuus Lioilujris, Douville

II. Subgenus Terebratulina, d'Orbigny .

III. Genus Waldhihnur, King

IV. Genus TdnhrahUa. d'Orbigny

V. Subgenus Mar/aseUa, Dall

VI. Genus Mec/erlia, King

VII. Subgenus Laqueus, Dall

VIII. Genus Bouclmrdia, Davidson

IX. Genus Kraussina, Davidson

X. Subgenus Mcgirliiia, Deslongchamps
XI. Genus Ai-fjiojpe, Deslongcbamps

XII. Subgenus Cistdla, Gray

XIII. ? Genus Givynla, King

XIV. Genus Plati/dia, Costa

XV. Genus Thecidium, Defrance

XVI. Genus Rhyncliondla, Fiscber ....
XVII. Subgenus Atretia, Jeffreys

CO ^

8
9

10
t)
6
2
3
1
5
2

1
8
1
2
2
6
2

LYOPOMATA, Owen=TRETENTERATA, King

4tli Family CRANiiuiE XVIII. Genus Crania, Retzius . .

f XIX. Genus Diseinn, Lamarck
5tli Family Discinib/e (^

6tli Family LiHGTrLiD^

4

1

XX. Subgenus Discinisca, Dall 6

r XXI. Geiuis Lingtda, Bruguit-re 8

\ XXII. Subgenus Glottidia 3

2?

1

6 Families. 22 Genera and Subgenera. 99 Species. 29 Uncertain Species.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 231

Classification of the Becent Brachiopoda.
ARTHEOPOMATA, Owen=CLISTENTERATA, King.

Family TEREBRATULIDiE.

Subfamily Terebratulin.5;, Dall, 1870.

I. Genus LiothyriSj Douville, 1879.

Liothyris vitrea, Born, sp., 1778.

Terebratula vitrea, var. minor, Philippi, 1836, = uffinis, Calcara, 1845.
L. vitrea, var. Davidsoni, Adams, 1867.
L. arctica, Friele, sp., 1877.
L. uva, Broderip, sp., 1835.
L. Moseleyi, Davidson, 1878.

L. spfiemidea, Pbilippi, sp., 1844, = T. Cvbensis, Pourtales, 1871.
L. Barttetti, Dall, sp., 1882.
L. suhquadruta, Jeffreys, sp., 1868-70.
L. Wyvillii, Davidson, 1878.

Uticertain Species.
Liothyris cernica, Crosse, sp., 1873.
L. Dalli, Davidson, 1878.

II. Subgenus Terebratulina, d'Orbigny, 1847.

Terebratuihm caput-serpentis, Linne, sp., 1767, = A.pubescens, Linne ; aurita, Fleming ; costata, Lowe ;
retusa, Linne; emaryinata and quadrata, Risso, = var. mediterranea, Jeffreys, 1878 ; Chemnitzii, Kiister ;
spatula, Menke ; Gervillei, Wood.

Terebratulina caput-serpentis, var. unguiculatu, Carpenter, 1865.

T. cailleti, Crosse, 1865.

T. septentrionalis, Couthouy, 1838 or 1839.

T. Wyvillii, Davidson, 1878.

T. Crossii, Davidson, 1882.

T.japonica, Sowerby, sp., 1846.

T. radiata, Reeve, 1860.

T. cancellata, Kocb, sp., 1843.

T. [Agulhasia) Davidsoni, King, 1871.

Uncertain Specie!:.
Terebratulina Cuniingi, Davidson, 1852.

T. abyssicola, Adams & Reeve, sp., 1850.

T. ? incerta, Davidson, 1878.

T. Murrayi, Davidson, 1878.

T. tuberata, Jeffreys, sp., 1868-70.

T. trigonia, Jeffreys, sp., 1878.

III. Genus Waldheimia, King, 1850.

Waldheimia Jlavescens, Lamarck, sp., 1819, = australis, Quoy, = incurva, Gray.

W.venosa, Solander, sp., \7S<^,= globosa, Lamarck; dilatata, Lamarck, = exiinia, Pbilippi, = Gaudl-
chaudi, Blainville, = Fontaineana, d'Orbigny ; physema, Valenciennes, 'MS., fide Reeve.

SECOND SERIES. — ZOOLOGY, VOL. IV. 31

232 DE. T. DAVIDSON ON RECENT BRACHIOPODA,

IValdheimia lenticularis, Deshayes, sp., 1839.

W. kerguelenensis, Davidson, 1878.

W. Grayi, Davidson, 1852.

TV. septigera, Loven, sp., 1846.

W, Raphaelis, Dall, 1870.

W. floridana, Pourtales, 1868.

Subgenus Macandrevia, King, 1859.

Waldhemia [Macandrevia) cratiium, Miiller, sp., 1776, = euthyra, Segueuza.
W. (M.) tenera, Jeffreys, sp., 1878.

Uncertain Species.
IValdheimia Wyvillii, Davidson, 1878.

Subfamily Te re bra telling.

IV. Genus Terebratella, d'Orbigny, 1847.

Terehratella r/orsc!/«, Gmelin, sp., 1768, = T. bilobata, Blainville, = magellanica,ChQvamt7., = chilends,
Broderip, = Soicerbyi, King, = ? lupiniis, Philippi.

T. transversa, Sowerby, sp., 1846; var. caurina, Gould, 1850; var. occidentalis, Dall, 1871.

T. coreanica, Adams and Reeve, sp., 1850, = T. Bouchardi, Davidson t =T. miniata, Gould, = T. Lama-
noni, Sclu-enck.

T. Blanfordi, L. Dunker, sp., 1882.

T. S'pitzbergensis, Davidson, 1852.

T. rubicunda, Sowerby, 1846, = T. inscunspicua, Sowerby, — sanguinea of several authors.

T. frontalis, Middeudorff, sp., 1849.

T. cruenta, Dillwyn, sp., 1817, = sanguinea, Solander MS. and of several other authors, = T. zelandica,
Deshayes, = Evansi, Davidson.

T. Maria, A. Adams, 1860.

Uncertain Species.

Terebratella pulvinata, Gould, sp., 1850.

T. rubiginosa, Dall, 1870, = suffusa, Dall.

T. Frielii, Davidson, 1878.

V. Subgenus Magasella, Dall, 1870.

Magasella flexuosa, P. P. Kiug, sp., 1835, = ? T. rhombea, Philippi.

M. crenulata, Sowerby, sp., 1846.

M. aleutica, Dall, 1872.

M. Adainsi, Davidson, 1871.

M. Gouldi, Dall, 1871.

M. Cumingi, Davidson, sp., 1852, = fibula, Reeve.

Uncertain Species.
Magasella patagonica, Gould, sp., 1850.
M. Icpvis, Dall, 1870.
M. ? Malvince, d'Orbigny, sp., 1846.
M. incerta, Davidson, 1880.
M. radiata, Dall, 1877.
M. labradorensis, Sowerby, sp., 1846.

DE. T. DAVIDSON ON EECENT BEACHIOPODA. 233

Subfamily MegeulinjE.

VI. Genus Megerlia, King, 1850.

Megerlia truncata, Linne, sp., 1767, var. monslruosa, Scacchi.

M. sanguinea, Chemnitz, sp., 1785, = erythroleuca, Quoy, var. Reevei, Da.\idson, = vs.r. pulchella, Sowcrby.

Uncertain Species.
Megerlia Wilkmoesi, Davidson, 1878.

VII. Subgenus Laqueus, Dall, 1870.

Laqueus californicm, Koch, sp., 1813, — Koc/ii, Kiister, var. vancouverensis, Davidson*.
L. rubellus, Sowerby, sp., 1846, = suffusus, Dall.
L. pictus, Chemnitz, sp., 1785.

Subfamily Magasin^e.

VIII. Genus Bouchardia, Davidson, 1849.
Bouchardia rosea, Mawe, sp., 1823, = tulipa, Blainville.

Subfamily Kraussinin^.

IX. Genus Kraussina, Davidson, 1861.

Kraussina rubra, Pallas, sp., 1766, = capensis, Gmel. (part).

K. cognata, Sowerby, sp., 1846, nee Chemnitz.

K. Deshayesi, Davidson, 1850, = capensis, Adams.

K. pisum, Valenciennes, apud Lamarck, sp., 1819, = T. natalensis, Kiister, ? J", algoensis, Sowcrl)y.

K. Atkinsoni, Teuison Woods, sp., 1878.

X. Subgenus Megerlina, Deslongchamps.

Kraussina [Megerlina) Lamarckiana, Davidson, 1852.
K. [M.) Davidsoni, Velain, 1877.

Subfamily Argtopi.n^^.

XI. Genus Argiope, Deslongchamps, 1842.

Argiope decoUata, Chemnitz, sp., 1785.

Uncertain Species.
Argiope ? globulifurmis, Schulgin, 1884.
A. Barroisi, Schulgin, sp., 1884.

XII. Subgenus Cistella, Gray, 1853.

Cistella neapolitana, Scacchi, sji., 1833, = ? C. biplicatu, Seguenza.

C cistellula, Searlcs Wood, sp., 1811.

C. Woodivardiana, Davidson, sp., 1866.

C. cuneata, Risso, sp., 1826.

('. lutea, Dall, 1870.

C. Barrettiana, Davidson, sp., 1866.

C. Kou-alevskii, Schulgin, sp., 1884.

C. Schrammi, Crosse, sp., 1866.

* The shell described as Me<jcrVui (Ismcnia) Jeffnynii, Dall, is the young of this species.

31'-

234 DE. T. DAVIDSON ON EECENT BRACHIOPODA.

Uncertain Species.
? Cistella lunifera, Philippic sp., 1836.

«

Subfamily (not yet determined).

XIII. Genus ? Gwynia, King, 1859.

Gwynia capsula, Gwyn Jeffreys, sp. (an immature form) =Terebratula capmla = Argiope capsula,
Jeffreys.

XIV. Genus Platydia, Costa, 1852.

Plahjdia anomioides (Scaccti), Philijjpi, sp., 184)4:,= Terebratula seminulum, Philippi, 1836, = Morrisia
anomioides, Davidson.

P. Davidsoni, Deslongchamps, sp., 1855.

Family THECIDIID^.

[XV. Genus Thecidium, Defrance, 1828.

Thecidmm mediterraneitm, Risso, 1826, = T. spondylea, Scacclii, = T. testudinaria, Michelotti.
T. Barretti, Woodward, MS., 1864.

Family RHYNCHONELLID^.

XVI. Genus Rhynciionella, Fischer, 1809.

Rhynchonella psittacea, Chemnitz, sp., 1785, = var. Woodwardi, Adams, 1863.
R. nigricans, Sowerby, 1846, = var. pyxidata, R. B. Watson, MS., 1880.
B. cornea, P. Fischer, MS. 1885, =? R. sicula, Jeffreys, nee Seguenza.
R. lucida, Gould, 1860.
R. Grayi, Woodward, 1855.
R. Doderleini, Davidson, 1886.

XVII. Subgenus Atretia, Gwyn Jeffi-eys, 1870.

Atretia gnomon, Jeffreys, 1869.
A. Brazieri, Davidson, 1886.

LYOPOMATA, Owen = TRETENTEUATA, King.

Family CRANIID^.
XVIII. Genus Crania, Retzius, 1781.
Crania anomala, Miiller, sp., l776, = distorta, Montagu, norvegica, Lamarck, orcadensis, Leach, alba,
Jeffreys.

C. turbinata, Poli, sp., 1795,= C. personata, part., = C'. rostrata et ringens, Hoeninghaus.
C. Suessii, Reeve, 1862.
C.japonica, Adams, 1863.

Uncertain Species.
Crania Pourtalesii, Dall, 1871. ?Var. of C. anomala.

DR. T. DAVIDSOTV ON EECENT BRACHIOPODA. 235

Family DISCINID.E, Gray, 1840.

XIX. Genus Discina. Lamarck, 1819.

Discina striata, Schumacher, sp., 1817, = D. osfreoides, Lamarck, 1819, = Z). radiosa, Gould, = _D. Evansi,
Davidson.

XX. Subgenus Discinisca, Dall, 1871.

Discinisca Iceins, Sowerby, sp., 1818.

D. lamellosa, Broderip, sp., 1835.

D. Cumingii, Broderip, sp., 1835, = Z). strigata, Broderip.

D. tenuis, Sowerby, sp., 1847.

D. atlantica, King, sp., 1868.

D. Stella, Gould, 18G0.

Uncertain Species.

Discinisca antiUarum, d'Orbigny, 1853.

Family LINGULID^.

XXI. Genus Lingula, Bruguicre, 1789.

Lingula anatina, Bruguiere, sp., 1789, = A. anatis, unguis, lingun, Chemnitzi, histula, = affinis Hancock.

L. Murphiana, King, MS., Mus. Cuming; Reeve, 1859, = a«a/i«a Hancock.

L. tumidula. Reeve, 1841.

L. Mans, Swainson, 1823.

L, exusta. Reeve, 1859.

L. jaspidea, Adams, 1863.

L. Adamsi, Dall, 1873.

L. Reevii, Davidson, 1880 (dim auctorum L. ovalis).

Uncertain Species.
Lingula smaragdina, Adams, 1863.
L. hirundo. Reeve, 1859.
L. lepidula, Adams, 1863.

XXII. Subgenus Glottidia, Dall, 1870,

Glottidia ulbida. Hinds, sp., 1845.

G. Palmeri, Dall, 1871.

G. Audebarti, Broderip, sp., 1835, = !,. pyramidata, Stimpson.

Uncertain Species.
Glottidia? antiUarum, Reeve, sp., 1861.
G. ? semen, Broderip, sp., 1835.

230 DR. T. DAVIDSON ON KECENT BEACHIOPODA.

APPENDIX.

The Anatomy of Crania from Dr. L. Joubin's " Recherches sur I'Anatomie des
Bracbiopocles Inarticules," Archives de Zoologie Experimentale, t. iv. p. 161,
1886. (Abstract.)

Dr. L. Joubin dretlged Crania turbinata, Poli {—C. rostrata, Hoeningliaus), from a belt of calcareous
rocks about 200 metres from the shore, on the rocky coast of Banyuls-sur-Mer in the Eastern Pyrenees,
in depths varying from 50 to 60 metres. The specimens were generally covered with algae, and greatly
resembled in colour and form the objects to which they had attached themselves. He kept them alive
for six months and then preserved them in alcohol, as he was leaving the neighbourhood. Other
specimens were transferred to Roscoff and suffered no ill-eifects from the change of water, which differs
much from that of the Mediterranean ; later, they were again removed to Paris, and were still living
fourteen months after they had been dredged. The sjjecies exhibited great tenacity of life ; exposed to
sunlight without change of water for months together, neither extremes of heat nor cold, light nor darkness,
appeared to affect them in any way. Although the specimens obtained in November were full of ova,
no eggs were deposited during captivity, consequently it was impossible to trace the embryonic
development of the genus.

In the course of exhaustive anatomical and histological investigations of this non-pedunculate
tretenterate Brachiopod with a wholly calcareous shell, Dr. Joubin recognizes the presence of two layers
in the structure of the hingeless shell, which is perforated by canals, the terminations of which in the
upper or free valve are arborescent, as described by Carpenter and King. The canals of the lower
and attached valve he shows to be irregular, slightly bifurcated, and non-arborescent in character. The
mantle lining the shells is so transparent as to be scarcely discernible. It adheres closely to the valves
and penetrates into the tubular perforations of the shell, and is permeated with yellow or whitish rami-
fications of a glandular aspect. These are the genital bands. The true colour of the mantle is slightly
green, due to special granulations contained in certain cells analogous to those of the red cells described
by M. Lacaze-Duthiers as present in Thecidium. The free portion of the mantle is covered with short
vibratile cilia, which cause incessant currents in the water admitted into the pallial cavity. Additional
currents are produced by the ruovements of the '' arms." The mantle is composed of a thin trans-
parent tissue, and the animal of Crania might almost be defined " as a layer of cartilaginous tissue
enclosed between two epithelia." The genitalia are contained in a fold of the mantle. The pallial
genital canals are from five to eight in number, uniting in one trunk on each side and for each valve,
and empty into the perivisceral cavity. The pallial cartilaginous tissue (" Stutzsubstance " of Van
Bemmelen) is thickest at the points of insertion of the muscles, where the shell-substance is not
perforated by canals. There are five pairs of muscles and an odd one. The mantle limits the size of
the visceral cavity, serves for the attachment of the muscles and of different membranes, and evidently
plays an important part in the respiratory processes and production of the shell. The cells of the

DR. T. DAVIDSON OX RECENT BRACHIOPODA, 237

" sponginous band " yield tlic calcareous particles for thickening tlic valves. The perforations in the
valves containing prolongations of the mantle subserve the nourishment of the lining tissue of the shell.
There are no calcareous spicules in the mantle of Crania, whicli resembles in general structure that of
Lingula and RJiijnchoneUa, but is simpler in character.

The bod}--walls in Crania are pierced by four orifices, the mouth at the top, the anus below on the
axis of the body, and on each side by the oviductal organs. No gastro-parietal bands are present in
Crania, and the ilio-parietals are comparatively insignificant. The brachial organs cannot be unrolled
in the small space between the gaping valves ; the brachial muscles are extremely rigid, and would
restrain free movements. Dr. Joubin maintains that the arms cannot be extruded beyond the shell-
margins in Crania. The numerous specimens in captivity under frequent observation for consecutive
months never extended their arms nor even the cirri, as figured by Barrett.

The stomach of Crania is filled with transparent mucus. The presence of Diatoms, the chief
nourishment of the animal, was frequently detected, also cells of filamentous pelagic algje, and of the
calcareous algae (Melobesia) common on the coast, fragments of Radiolarians and of sponge-spicules.
The rectal portion of the alimentary canal, which is voluminous and well defined, extends from the great
adductor muscles to the median muscle (Hancock's mesenteric). The non-lateral position of the anal
orifice, which is situated in Crania between the two posterior adductors exactly in the median line, is a
unique feature among the Braehiopoda, and recalls the analogous position of that organ in the Bryozoa.
There is no trace of the existence of a heart or arterial system. All the organs are bathed in the colour-
less liquid filling the perivisceral cavity. The rudimentary nervous sy.stem is divisible into two sections —
the brachial ganglion, whence radiate the numerous nerves of the arms, and a minute peri-cesophageal
collar with a slight dorsal enlargement = the cerebral ganglion of ^Mollusca. The two centres are
connected by nerves passing down each side of the oesophagus to the base of the arms, and this union
leads Dr. Joubin to believe that arms may be regarded as an organ of sense, those of smell and taste being
localized in the ciliated brachial gutter at their base near the mouth *. No organs of sight or hearing are
present. Dr. Joubin maintains that the sexes are distinct in Crania. There are six genital organs,
three on each side of the body, one on the ventral and one on the dorsal, and the third is situated on the
perivisceral cavity. The oviductal functions of Owen's so-called " hearts •" and of Morse's segmentary
organs is demonstrated.

From a comparative study of the articulate and inarticulate Braehiopoda, it becomes evident that
the pedunculated Lingula and Discina with horny shells arc much more closely related to each other
than the non-pedunculate calcareous Crania, which appears to have affinities with the articulate Rhyn-
chonella and Thecidium. Crania seems to be intermediate in character between the two great groups,
and the position of the anus in the median line distinguishes it not only from the rest of the Tretenterata
but from all other Braehiopoda. While fully recognizing the structural differences between these two
groups. Dr. Joubin maintains tliat Crania and Rhynchonella each present in a diflFereut way characters
which are common to both. The Braehiopoda, he concludes, approach the Bryozoa more than any other
roup of organisms, and are sufficiently distinct to form a class absolutely independent of all otiier
animals. [A. C]

b

»

* Prof. J. W. Sollas has recently adduced evidence (Proc. Roy. Dublin Soc. 1SS7, pp. .jlS-^SO) to sliow tliat the o;ecaI
processes are sense-organs. They are obviously composed of epithelial cells, and exhibit traces of an axial fibre continuous
with the nerve-celLs of the mantle.

238 DE. T. DAVIDSON ON RECENT BRACHIOPODA.

NOTE.

Since tlie publication of Dr. Davidson's and Mr. W. H. Dalton's extensive " Bibliography
of the Brachiopoda," in tbe volume of the Palreontographical Society, for 1886, the
following memoirs on tbe recent species have been issued, or were omitted therein : —

Beyer, H. G. " The Structure of Lingulapyramidata." Studies from the Biological Laboratory of the

Johns Hopkins University, Baltimore, vol. iii. (1886), pp. 228-245 ; 5 plates.
Blochman, F. "On the Structure of the Brachiopoda." Zool. Anzeig. viii. 1885, pp. 164-167.
Brazier, J. " List of the Brachiopoda or Lamp Shells found in Port Jackson and on the coast of New

South Wales." Proc. Linn. Soc. N. S. Wales, vol. iv. p. 399, 1879.
Crane, Agnes. " On a Brachiopod of the Genus Atretia " (named in MS. by the late Dr. T. Davidson,

A. Brazieri). Proc. Zool. Soc. 1886, pp. 181-184.
Davidson, Thomas. " On a living spinose RltyncJionella from Japan" (with figure). Ann. Mag. Nat.

Hist. 5th ser. vol. xvii. pp. 1-3, 1886; (posthumous; edited by Agnes Crane).
Dall, William H. " The MoUuscoidea of the Blake Expedition. — Brachiopoda," j)p. 199-205. Bull.

Mus. Comp. Zool., Harvard; 1 plate.
JouBiN, L. " Sur les organes digestifs et reproducteurs chez les Brachiopodes du genre Cranie."

Comptes Rendus, xcix. 1884, pp. 985-7.

. " Sur TAnatomie du genre Cranie." Comptes Eendus, c. 1885, pp. 464-6.

■ . " Sur TAnatomie du genre Discine." Comptes Rendus, ci. 1885, pp. 1170-1.

. " Recherches sur FAnatomie des Brachiopodes Inarticules." Archives Zool. Experim. et

Ge'n. 1886, 2" ser. t. iv. pp. 161-303, pis. vii.-xv.

. " Sur FAnatomie des Brachiopodes articulees." Bull. Soc. Zool. France, t. xii. ; 1 plate.

ScHULGiN, M. A. " Argiope Kowalevskii. — Ein Beitrag zur Kenntniss der Brachiopoden." Zeitschrift

fiir wissenschaftliche Zoologie, Leipzig, 1884, Bd. xli. pis. viii. & ix. pp. 117-144.
SoLLAs, J. W. "On the Cascal Processes of Shells of Brachiopoda." Proc. Royal Dublin Society, v.

pp. 318-20; 1 plate (1887).

DESCRIPTION OF THE PLATES.

Plate XXVL*

Figs. 1-8. Discinisca lamellosa, Broderip, sp. 1-3. Exterior of shell ; 4. Interior of upper valve. 5.
Interior of perforated or lower valve ; same specimen ; Bay of Callao, Peru (Davidson Coll.,
Brit. Mus.). 6. Group of young and old, after G. Sowerby. 7. Interior, to show labial
appendages. 8. A magnified view of the superior mantle-lobe injected, with ovary, digestive
and nervous system, after Owen, q, the mouth ; r, oesophagus ; u, the anus ; /, intestine ;
IV, ovaries ; v, liver.

Figs. 9-11. Discinisca Icevis, Sowerby. 9. Perforated or lower valve, after Reeve. 10. A group of
specimens, from Callao, Peru (Davidson Coll., Brit. Mus.). 11. A small group of species from
off Conception Island (Davidson Coll., Brit. Mus.).

Figs. 12-17, 17a. Discinisca tenuis, Sowerby. 12-14. Types, after Sowerby; no habitat given.
15. Exterior of the lower valve. 16. Interior of same valve. 17. Another specimen.

Figs. 18-22. Discinisca atlantica. King. 18. Natural size, dredged by the ' Challenger ' Expedition,
North Pacific, at a depth of 2050 fathoms. 19. Specimens attached to Limopsis aurita,
Brocchi ('Challenger' Exped., Brit. Mus.). 20. Upper valve, with its long, slender, barbed

* Disdna striata is figured on PI. XXV. of Part II. of this Monograph.

DB. T. DAVIDSON ON RECENT BRACIIIOPODA. 239

setfc, dredged by ' Challenger ' Expedition between the Cape Verde Islands and Fernando

Noronha, South America; much magnified. 21. Lower valve, dredged by the 'Valorous'

Expedition, North Atlantic. 2.2. One of the barbed setje, much enlarged.
Figs. 23-26. D'lscbmra Cuyninr/i, Broderip. 23. Upper valve, nat. size. 23 a. Enlarged. 2i. Interior

of lower valve, nat. size. 2o. The same, enlarged. 25 a. Exterior of upper valve, enlarged.

All from St. Helena, and Panama, collected by 11. Cuming (Davidson Coll., Brit. Mus.).

26. O. strigata, Broderip, after Broderip.
Figs. 27-30. Discmisca siella, Gould. 27, 20. Dredged by the ' Challenger ' Expedition in lat. 8° 56' S.,

long. 136° 5' E. ; off Bermuda (Brit, Mus.). 28, 29. Much enlarged. 30. A large example,

after Reeve, nat. size. China Sens. (Cuming Coll., Brit. Museum.)
Figs. 31, 31 a. Discinisca antillarum, d'Orbigny. Cuba, INIartinique, much enlarged, after d'Orbigny.

Plate XXVIl.

Figs. 1-8. Crania anomala, Miiller. 1. Exterior of shell; Oban. 2. Interior of upper valve.
3. Interior of attached valve ; same locality (Davidson Coll., Brit. ]\Ius.). 3ff. Specimen
dredged by L. Barrett, Coast of Norway; enlarged. 4. Interior of a specimen in the
Jermyn-Strcet Museum, enlarged to show the labial appendages. 5. Vertical section of
shell of C. anomala, after Carpenter, showing its successive layers, traversed by vertical
channels, which present an arborescent division near the external surface, and a marked
contraction near the interior ; magnified 40 diameters. 6. External surface of shell (after
Carpenter) , showing the radiating arrangement of the subdivisions of its canals; magnified 100
diameters. 7, 8. Vertical sections of same, after King, showing that the vertical canals, on
approaching the dark-coloured or epidermal portion of the external layer, become minutely
subdivided into fi'om 2 to 5 branchlets, which appear like arborescent tufts.

Figs. 9, 9 6. Crania anomala, var. alba, Jeffreys; Shetland. After Jeffreys's type.

Figs. 10, 11. Crania japonica, A. Adams; Gotto, Japan (Davidson Coll., Brit. Mus.). 10. Natural
size. 10 a, 6. Exterior of upper valve, enlarged. 11. Interior, enlarged.

Figs. 12,12a. Crania Poiirtalesi, Dall (C anomala''! var. Ponrtalesi, after Dall's figure); Sambos,
Florida.

Fig. 13. Crania Suess'i, Reeve; Sydney, Australia (after Reeve) . (Cuming Coll., Brit. Mus.)

Figs. 14-23. Crania turbinata, Vo\\,= Crania rostrata, Hoeninghaus. 14. Exterior of upper valve (after
Poll). 15, 15 6. A very conical example from the ]\Iediterranean Sea (Davidson Coll.). 16.
Interior of lower valve, from another Mediterranean specimen; natural size (Davidson Coll.).
17. Interior of attached valve, enlarged. 18. Interior of upper valve, enlarged. 19,20. Other
specimens from the same habitat (Davidson Collection, Brit. Mus.). 21. Crania rostrata,
Hoeninghaus's figure ; Mediterranean ; = C. turbinata. Poll. 22. Crania personata, after
Sowerby ; doubtless a malformed specimen of C. turbinata. 23. Another similar specimen ;
from the Mediterranean (Davidson Coll., Brit. Mus.).

Plate XXVIII.

Figs. 1, 1 a. Crania turbinata, var. ringens, after Hoeninghaus ; Mediterranean. 1 a. Enlarged.

Figs. 2-4. Glottidia albida. Hinds. 2 & 4. Specimens from the Bay of Magdalena, California (Davidson

Coll., Brit. Mus.) . 3. A larger example, after Reeve ; same habitat (Cuming Coll., Brit.

Mus.).
SECOND SERIES. — ZOOLOGY, VOL. IV. 32

240 DE. T. DAVIDSON ON EECENT BEACHIOPODA.

Figs. 5-6 a. Glottidia Palmeri, Dall. Dredged by Dr. Palmer in the Gulf of California, on the Lower

Californian side, opposite the mouth of the Colorado river; one of ten examples ohtained;

presented by Mr. Dall (Davidson Coll., Brit. Mus.). 5 a. Interior of dorsal valve. 6 a. Of

ventral valve.
Figs. 7-9. Glottidia Audebarti, Broderip. A series of specimens from Guayaquil. 7. Broderip^s type.

8. After Reeve. 9, 9 a. Exterior ; 9 b. Interior of ventral valve, showing the two diverging

septa. 9 c. Interior of dorsal valve, showing a single median septum (Davidson Coll.,

Brit. Mus.) .
Figs. 10, I0«-1I. Glottidia Audebarti. These specimens, representing L. pyramidata, Stimpson, sp.,

were dredged by Prof. E. Morse in North Carolina waters (Davidson Coll., Brit. Mus.).
Fig. 12. Glottidia 1 semen, Broderip; Isle of Plata, West Columbia. After Broderip. Type in Zool.

Dept., Brit. Mus.
Fig. 13. Glottidia? antillarum, Reeve. After Reeve. Martinique (Cuming Coll., Brit. Mus.).
Figs. 14, 15. Lingula tumidula, ^eeve. 14. From Masbate, Philippines ; after Sowerby. 15. Moreton

Bay, Australia; after Reeve. (Brit. Mus.)
Fig. 16. Lingida lepidula, A. Adams, probably the young stage of another species ; Seto-Uehi (Akasi),

Japan (Davidson Coll., Brit. Mus.).
Figs. 17, 18 «. Lingula Reevei, Davidson, formerly L. ovalis. 17. A fine large specimen, after Reeve;

Sandwich Islands (Cuming Coll., Brit. Mus.). 18, 18a. Another specimen; same habitat

(Davidson Coll., Brit. Mus.).
Fig. 19. Lingula Adamsi, Dall. Dredged by Capt. Weston near the shore of the island of Formosa

(Davidson Coll., Brit. Mus.).
Figs. 20-21 a. Lingula exusta, Reeve. 20. After Reeve ; Moreton Bay, Australia (Zool. Dept., Brit.

Mus.). 21, 21 a. Another specimen ; same habitat (Davidson Coll., Brit. Mus.).
Fig. 22. Lingula hirundo, Reeve. After Reeve. Port Curtis, north-east Australia (Cuming Coll., Brit.

Mus.).
Figs. 23, 24. Lingula jaspidea, A. Adams. 23. Adams's type ; Mososeki, Japan. 24. A fine large

example dredged by Sir E. Belcher (Davidson Coll., Brit. Mus.).
Kg. 25. Lingula smaragdina, A. Adams ; Yobuko, Japan. Adams's type (Davidson Coll., Brit. Mus.).

Plate XXIX.

Figs. 1-8. Lingula anatina, Lamarck. 1, 2, 4, 5. A series of specimens of a brilliant emerald-green, in
diftcrent stages of development, dredged at low water by the ' Challenger ' Expedition off
Zamoanga, Phihppines. 1. Zool. Dept., Brit. Mus., others Davidson Coll. 3. A specimen from
Manilla, collected by Mr. H. Cuming (Davidson Coll., Brit. Mus.). 6. Interior of upper valve.
7. Interior of lower valve. 8. A specimen with its peduncle seen in profile, after Gratiolet :
a, ventral valve ; b, dorsal valve ; c, base of peduncle.

Figs. 9, 10. Lingula affinis, Hancock. 10. Shell from the type forwarded, but which I take to be a
valve of Lingula anatina. 9. Ventral view of the animal of Lingula affinis, after Hancock
(Trans. Roy. Soc. vol. cxlviii. 1858, pi. Ixvi. fig. 3). "The dorsal labial lobe divided longi-
tudinally, and one half of it turned back, so as to expose the pallial chamber; the marginal
setae are not represented : a a, pallial sinuses ; b, marginal fold ; c, liver seen through the wall
of the perivisceral chamber ; d, dorsal ovaries ; e, e, intestine; /, lateral walls of the body, or
perivisceral chambers ; g, anal nipple ; h, brachial apparatus ; i, cirri ; j, adjustor muscles ;
k, divaricators ; /, anterior wall of body."

DE. T. DAVIDSON ON RECENT BEACHIOPODA. 241

Fig. 11. Linyula MurjMana, King, MS. A large example with its pcduuclc; from Morcton Bay,

Australia (Davidson Coll., Brit. Mus.).
Figs. 12, 13. Lingula Mans, Swainson. 12. A fine example with peduncle, after Reeve; China Seas

(Cuming Coll., Brit. Mus.). 13. A normally-shaped example (Davidson Coll., Brit. Mus.).

PLA.TE XXX.

Figs. 1-3. Lingula Murphiana,'\Lmg. 1. Exterior of sliell. 2. Interior of dorsal valve. 3. Interior of
ventral valve ; Moretou Bay, Australia (Davidson Coll., Brit. Mus.).

P^gs. 1—5. Lingula sp. ? Bay of Yeddo, Japan (Davidson Coll., Brit. Mus.).

Fig. 6. Lingula anatina, Lamarck ; from Japanese Seas, showing extremity of peduucle (Davidson.
Coll., Brit. Mus.).

Figs. 7-10. Young stages of Glottidia Audebarti, Broderip, = L. pyramidata, Stimpson ; after W. K.
Brooks (/. c). Fig. 7. Dorsal view of the youngest larva figured, x 250 diameters. Fig. 8. A
little older larva. Fig. 9. Dorsal view of somewhat older embryo. Fig. 10. Ventral view of
a small Lingula soon after it becomes sedentary. The letters have the same signification in all
the figures. A. Dorsal or aboral valve of shell. B. Ventral or oral valve. C. Peduncular
or posterior eud of shell. D. Anterior end. a a, hinge-teeth of aboral valve ; 6 />, hiuge-teeth
of oral valve ; c, semicircular plate of aboral valve ; d, median tentacle ; d d*, the pair of oral
tentacles ; d 2, d 3, d 4:, d i>, the tentacles of one side numbered according to their order
of appearance, d, n, the most recent pair of tentacles, in process of development at the sides
of the aboral tentacles; e, the lip; /, lateral walls of the body (parietal bands) ; g, body-
cavity; A, liver; i, oesophagus ; /;, hepatic chamber of stomach ; /, intestinal chamber of stomach ;
ni, intestine ; n, anus ; o, mouth ; p, central and side muscles = at this stage the central, trans-
median, and lateral muscles of King ; q q, the lophophore ; r, posterior unpaired muscle, =5r, or
umbonal muscle of King; s, peduncle; s*, free end of peduucle; «**, cavity of peduucle;
/, pallial cavity; u, ventral end of anterior lateral muscle; m**, dorsal end of transmediau muscles;
r, pallial sinus ; iv, its opening into the body-cavity ; x, venti-al portion of nerve-ring, x*,
(psophageal commissure ; x**, ganglionic enlargement of x*; x***, otocyst ; //, retractor muscles;
z, reflection of the dorsal portion of the body-wall on to the inner surface of the shell.

Fig. 11. Diagram of longitudinal section of the embryo at stage shown in fig. 9. a, tips of valves;
b, thickened margin of mantle ; c, mantle ; d, dorsal median tentacle ; e, lophophore ; /, li p;
//, mouth; /(, oral cavity; i, body-cavity; k, wall of oesophagus; /, oesophagus; m, hepatic
chamber of stomach ; n, intestinal chamber of stomach ; o, intestine ; q, ventral ganglion ;
r, posterior muscle ; s, dorsal valve of shell ; t, ventral valve of shell.

Figs. 12-1 1. Structures of Glottidia Audebarti, Broderip, = Lingula pyramidata, Stimpson ; after H. G.
Beyer (/. c). Fig. 12. Transverse section through lateral body-wall: c.c, ectodermal covering;
vac, vacuoles ; I.e., lime-cells ; *./., supporting lamella ; p.e., modified peritoneal epithelium ;
r.np., cross-sections of ripe spermatophores ; sp., spermatophores. Fig. 13. Longitudinal
section through intestinal canal Ijclow stomach: p.c, dense layer of i)critoncal epithelium;
.it., supple layer of supporting lamella; w., wall of intestine; ci/., ciliated internal layer of
same. Fig. 14. Transverse section through margin of mantle, shell, and mantle-sinus : cu.,
cuticle; A., hair ; sh., body of shell diagrammatically represented ; s./., supporting fibres; ec,
ectodermal layer lining shell; y.o., young ova; g.r., generative ridge contained within; ni.s.,
mantle-sinus ; sp., spermatophores ; ni.m., mantle margin ; cc, ectodermal layer ; pL, plexus of
corpusculated supporting fibres or " sensory ceils " of Schulgin.

ADDENDA ET CORRIGENDA.

Part I. p. 29, line 20, for " W. H. Binney " read W. G. Binney.
Part II. p. 98, line 4:, for " Heads and Pigs Bock" read Sow and Pigs Rocks,
p. 103, note, for " vancoxmerensis" read vancouveriensis.
p. 109, line 4 from bottom, for " near Bird's Island, North Australia," read from Bird Island,

Nortli-east Australia,
p. 110, line 2, add " and by Mr. J. Brazier, at Sandal Bay, N.W. of Lifrou, Loyalty Islands."
p. Ill, line 22, for " South Australia" read New South Wales.
p. 124, last line, /or " Dredged in great abundance by Mr. Brazier in Double Bay " read Found

under stones at the outer point of Double Bay, Port Jackson, New South Wales,
p. 125, line 3, for " Tamai " Heads read Tamar Head.

p. 162, four lines from bottom, add " Oft' Barbados in 100 fathoms ; St. Vincent and Mont-
serrat, 88 fathoms " (Dall, Bull. Mus. Comp. Zool. Harvard, 1886, vol. xii. p. 205).
p. 182, " PI. XXV. figs. 6, 7, & 7 a," for " Dr. Gwyn Jefl'reys " read Mr. Herman Friele.

[A.C.]

i]

INDEX.

Agulhasia, 36.

Davidsoni, 3G.
Air-breathing Organ in pulmouiferous

Gasteropods, IK'J.
Algffi, Kraussina rubra = T. rubra,

attached to, 120.
Anomia, 195.

aquilina, 163.

capcnsis, 89, 1 19.

caput-serpentis, 17, 19.

cognata, 121.

craniolaris, ISS.

cruenta, 1U8, 110.

decollata, 128.

dotruucata, 128.

disculus, 103.

peloritana, 56.

Pera, 141.

picta, 114.

psittacea, 163.

pubescens, 17.

retusa, 17.

rosea, 115.

rostrum psittacea, 163.

rubicunda, 89, 110, 119.

rubra, 119.

sanguinea, 87, 88, 103, 108, 110,
115.

sanguinolcnta, 108.

striata magellanica, 76.

striata, promontorii bonoe spei,
110.

truncata, 103, 104.

turbinata, 183, 188.

vcnosa, 49, 50, 71.

vitrea, 6, 01.
Appendix, 175, 236.
Area, Terebratulina cancellata at-
tached to, 36.
Argiope, Diagrammatic view of
muscles of, 138.

Argiope, 3, 4, 30, 208, 230, 233.

Antillarum, 145, 146.

Barrettiaua, 145.

Barroisi, 128, 147, 233.

biplicata, 131, 136, 142.

capsula, 150, 151, 234.

cistellula, 139, 149, 150.

cisteUuIum, 151.

cuneata, 141, 142.

decollata, 128, 129, 130, 142,
146, 180, 233.

detruncata, 129.

Forbesii, 131.

globuliformis, 128, 147, 233.

Kowalevskii, 147, 238.

luuifora, 149.

neapolitana, 131, (egg, embryo)
]32,(larva)133,136, 140, 150.

Pera, 141.

Schrammi, 148.

Woodwardiana, 140.

(Cistella) neapolitana, 135 ;
(muscles) 138.

(Terebratula) Iuiiifera=T. cis-
teUula, 149.
Argiopina;, 4, 127, 230, 233.
Arthropomuta=Clistcnterata, List of,

4, 5, 230, 231.
Ascidia, Kraussina rubra=T. rubra,

attached to, li'O.
Ascidia;, affinity to Brachiopoda, 199.
Astarte, 185.
Atretia, 4, 173, 230, 234.

Brazieri, 175, 182, 234.

gnomon, 16, 173, 174, 182, 234.
Atrypa reticularis, 167.

"Bee do perroquct," 163, 165.
Bouchardia, 4, 115, 117, 230, 2.33.

Cumingii, 98.
fibula, 98.

SECOND SKRIES. — ZOOLOGY, VOL. IV.

Bouchardia

Labradorensis, 102.

rosea, 115, 116, 117, 118, 179,
233.

tulipa, 98, 116,233.
Brachiococle or brachial chamber, 210.
Brachiopoda, 199.

affinity to Ascidia^ 199.

Bibliography of, 238.

Classification of, 230-235.

Cardium, Terebratulina cancellata

attached to, 30.
Caryophyllia

ramosa, 155.
Chonetes, 118.
Cidaris, Terebratulina cancellata

attached to spines of, 30.
Cistella, 3, 4, 127, 128, 130, 131,
230, 233.
AutOlarum, 143, 148, 181.
Barrettiana, 128, 142,143,145,
146, 148, 181, 233.

, var. rubrotincta, 145.

Barroisi, 180.
bipUcata. 18ii, 2.33.
cistellula, 128,139, 150,180, 233.
cuneata, 128, 136, 141, 142,

146, 180, 233.
globuliformis, 180.
Kowalevskii, 128, 143, 147.
(muscular arrangm.) 148,
ISO, 233.
lunifera, 128, 149, 150, 180.

233, 234.
lutea, 128, 142, 143, 181, 233.
neapolitana, 128, 131, 136, 139.
143, 148, 180, ( = biplicata)
233.
pentalaria, 142.
rubrotincta, 140, 181.

33

244

INDEX.

Cistolla

Schrammi, 128, 146, 148, 181,
233.

, var. rubrotincta, 145.

Woodwardiana, 12S, 140, 141,
ISO, 233.
Classification of Ke cent Brachiopoda,

230-23.5.
Clistenterata, 4, 5, 230, 231.
Crania, anatomy of, 236, 237.
Crania, 4, 169, 183, 195, 198, 208,
227, 230, 234, 238.
abnormis, 192.
alba, 185, 234.

anomala, 183, 184, 185, 186
(dorsal and ventral surface)
187, 190, 191, 234, 239.

, var. alba, 184, 239.

, var. Pourtalesi, 234, 239.

, var. turbinata, 189.

distorta, 234.

ignabergensis, 187.

japonica, 34, 183, 191, 192, 234,

239.
norvegica, 183, 18^, 234.
orcadensis, 234.
personata, 183, 188, 190, 234,

239.
Pourtalesii, 183, 188, 234, 239.
radiosa, 182, 193, 194.
ringens, 188, 189, 190, 191, 234.
rostrata, 188, 189, 190, 191,

192, 234, 236, 239.
striata, 192, 193, 194.
Suessii, 183, 192, 234, 239.
turbinata, 183, 184, 185, 188,
190, 234, 236, 239.

, var. ringens, 239.

Craniid*, 4, 183, 184, 189,230,234.
Criopoderraa

turbinatum, 188, 190.
Criopus, 190.

anomalus, 183.

fimbriatus, 188.

orcadensis, 184.

Cryjitopora gnomon, 173.

Delthyris

dorsata, 76.

spatula, 18.

trunoata, 104.
Development of Egg, 133.
DimereUa gnomon, 173, 174.
Discina, 4, 188, 192, 193, 195, 208,
227, 230, 235, 237.

antiUarum, 204.

Discina

atlantica, 200, 201.

Cumingi, 202.

Evansi, 182, 193, 235.

fallax, 202.

Isevis, 195, 197.

lamellosa, 187, 193, 197.

norvegica, 193.

ostreoides, 183, 192, 193, 194,
235.

radiosa, 193, 235.

Stella, 204.

striata, 182, 192, 193, 203, 235.

(Discinisca) lameUosa, 197.
DisoinidK, 4, 184, 189, 192, 230, 235.
Discinisca, 4, 193, 195, 230, 235.

antiUarum, 193, 204, 235, 238.

atlantica, 16, 38, 67, 193, 200,

201, 202, 203, 204, 205, 235,
238.

Cumingii, 193, 202, 203, 235,

238.
Ifevis, 193, 195, 196, 197, 201,

202, 235, 238.

lamellosa, 193, 196, 197, 198,

235, 238.
steUa, 34, 193, 204, 235, 238.
strigata, 235.
tenuis, 193, 196, 197, 235,238.

Egg, Development of, 133.
Eudesia floridana, 59.

Frenula

Jeffreysi, 103, 113.
sanguinea, 109.

Gasteropods, Air-breathing Organ in

pulmouiferous, 199.
Genus and species uncertain, ] 50.
Glossothyris, 16.
Glottidia, 4, 205, 221, 230, 235.

albida, 20(i, 208, 221, 222, 223,

224, 235, 239.

, var. Palmeri, 222.

antiUarum, 206, 224, 228, 235,

240.
Audebarti, 206, 208, 223, 224,

(pyramidata) 225, 226, 235,

240, 241.
Lesueuri,223.

Palmeri, 206, 222, 223,235,290.
pyramidata, 206, 222,223, 224,

225, 229, 235.

semen, 206, 229, 230, 235, 240.
Gryphus vitrea, 6.

Gwynia, 4, 151, 230, 234.

capsula, 150, 152, 180, 234.

(Argiope) capsula, 151.
Gypidia psittacea, 163.

Hemithyris

Grayi, 169.
lucida, 168.
nigricans, 170.
psittacea, 163, 164.

Isis, 196.
Ismenia, 103.

JeiTreysi, 103, 113.

pulchella, 43.

Reevei, 110, 179.

sanguinea, 33, 109, 110.

Kjaussia, 4.

Atkinsoni, 127.
cognata, 121.
Deshayesii, 122.
Lamarckiana, 124.
pisum, 123.
rubra, 119.
Kraussina, 4, 118, 230, 233.
algoensis, 233.

Atkinsoni, 118, 127, 179, 233.
capensis, 122, 123, 233.
cognata, 1 18, 121, 122, 179, 233.
Davidsoni, 118, 121, 125, 126.
Deshayesi, 118, 122, 123, 126,

179, 233.
Lamarckiana, 43, 118, 121, 122,

123, 124, 125, 126, 127.
natalensis, 233.
picta, 126.
pisum, 118, 120, 122, 123,124,

125, 126,179,233.
rubra, 38, 86, 89, 118, 119,

( attached to Ascidia and A IgEc)

120, 121, 122,123,124, 125,

179, 233.
(Megerlina) Lamarckiana, 124,

127, 179, 233.
Kraussininoe, 4, 118, 230, 233.

Lampas

psittacei, 163.
sanguineus, 87.
Laqueus, 4, 5, 111, 230, 233.

californicus, 52, 53, 111, 112,
113, 178, 233.

, var. vancouveriensis, 103,

111,113,178.
picta, 33.

INDEX.

245

Laqueus

pictus, 111, 114, 115, ITS,

205, 2-S3.
rubeUa, 33, 113.
mbellus. 111, 113, 114, 178,

233.
suflfusus, 111, 113, 114, 178.
Larva, Development of, 1st and 2nd

Period, 133, 134.
Lepar seu Patella, Rostrum anatis,

206.
Limopsis aurita, 38, 201.
Singula, 4, 5, 13, 30, 187, 198, 202,
205, 208, 227, 230, 235.

Adamsi, 34, 205, 215, 218, 219,

235, 240.
affinis, 205, 206, 215, 235, 240.
albida, 221.

anatina, 34, 200, 205, 206, 207,
208, 209, 210, (dorsal and
ventral valve) 211, (muscular
system) 212, 214, 215, 216,
217, 218, 220, 225, 235, 240,
241.
anatis, 235.
anatoni, 210.
antillarum, 228.
Antoni, 217.
Audebardi, 223, 225.
Audebarti, 206, 223, 225.
Chemnitzii, 206, 235.
compressa, 216.
Dumortieri, 218.
exusta, 205, 217, 235, 240.
hians, 205, 210, 217, 218, 235,

241.
hirtula, 206, 235.
birundo, 205, 220, 235, 240.
jaspidea, 34, 205, 218, 235, 240.
lopidula, 34, 205, 218, 220,

235, 240.
Lesueuri, 223.
lingua, 235.
Murpbiana, 205, 211, 215, 216,

217, 218, 235, 241.
ovalis, 219. 220,235.
pyramidata, 208, 223, 226, 227,
238, 241.

(=Glottidia Audebarti).

226, 227.
Reevii, 205, 219, 235, 240.
semen, 220, 229.
smaragdina, 34, 205, 220, 235,

240.
tumida, 216.

Liiigula

tumidula, 2o5, 216, 21S, 219,

235, 240.
unguis, 235.
(Glottidia) Audebarti, 208.

( ■) pyramidata, 2, 208, 214,

215, 223.
Lingula (Glottidia), from Cuba, 229.
Lingulella, 227.
LingulidK, 4, 202, 205, 208, 222,

230, 235.
Liothyris, 4, 230.

arctica, 5, 6, 10, 68, 231.
Bartletti, 14, 231.
ccrniea, 6, 16, GS, 231.
cubensis, 11, 14, 08.
DaUi, 231.

Moseloyi, (i, 11, 16, 68, 231.
spbacnoidca = cubensis, 6, 68.
sphenoidea, 11, 12, 13, 14, 68,

231.
subquadrata, 6, 14, 68, 231.
uva, 6, 10, 11, 68, 231.
vitrca, 5, 6, 7, 8, 9, 11, 13, 14,
16, 21, 64, 67, 231.

, var. Davidsoni, 9, 68,

231.

, var. minor, 9, 10, 68,

231.
Wyvillii, 6, 15, 16, 68, 231.
Lyopomata = Tretentorata, 4, 183,
230, 234.

Macandrevia, 5, 40, 232.

cranium, 62, 65.

tencra, 10.
Magadilbrm stages, 5, 107, 110.
Magas patagoniea, 99, 100.
MagaseUa, 4, 5, 53, 91, 92, 94, 2.30,
232.

Adamsi, 33, 92, 90, 97, 177,
232.

alcutioa, 92, 95, 102, 177, 232.

crenulata, 92, 94, 95, 177, 232.

Cumingi, 92, 97, 98, 117, 118,
177, 178, 232.

fibula, 177.

flexuosa, 75, 77, 92, 177, 232.

Gouldi, 33, 92, 96, 177, 232.

inoerta, 92, 101, 178, 232.

inconspicua, 85.

labradorensis, 92, 102, 177, 232.

l;evis, 92, 100, 178, 232.

Malvina;, 92, 100. 101, 178,

MagaseUa

patagoniea, 92, 95, 99, 177,

232.
radiata, 92, 101,178, 232.
rhombea, 232.
spftzbergensis, 83.
suffusa, 75, 177.
Willemoesi, 111.
Magasinai, 4, 115, 230, 233.
Malleus, 205.
Mannia, 174.
Megathyns, 127, 131.
ei-stdlula, 139.
decoUata, 129, 144.
detrunoata, 128.
oblita, 104.
Megerlea stage, 64.
Megerlea pulcbella, 109.

sanguinca, 109.
Megerlia, 4, 30, 57, 103, 126, 230.
erythroleuca, 233.
incerta, 38, 201.
JefFroysi, 103, 113, 178.
monstruosa, 155, 156.
oblita, 104.
pulcbella, 33, 43, 109, 110,

179.
Reevei, 33, 179.
sang\iinea, 33, 103, 108, 109,
179, 233.

, var. pulcbella, 179, 233.

, var. lleevei, 109, 233.

truncata, 13, 103, 104, 105,
106, 107, 108, 121, 125, 155,
156, 178, 233.

, var. monstruosa, 103, 108,

179, 233.
Willemoesi, 103, 111, 179, 233.
(Ismenia) Jeffreysii, 233.

( ) sanguinea, 103.

Megerliform stages, 5, 110.
Megerlina, 4, 103, 118, 230, 233.
Davidsoni, 126.
Lamarckiana, 124.
MegerKuffi, 4, 103, 230, 233.
Meleagrinaj margaritifera;, 11.
Morrisia, 130, 153.

anomioides, 152, 234.
Davidsoni, 154.
gigantea, 104.
lunifera, 149.
semiuulum, 152.
Muscles, (lateral) 211, (transmedian)

211.
MytUus lingula, 198, 206.

246

INDEX.

Xeomenia, 3.

Jfeothyris lenticularis, 52.

Obolus, 227.
Oculina, 21.

Orbicula. muscular system of, 19.5,
199, 208.

anomala, 183.

antillarum, 204.

Cumingii, 202, 203.

Evansii, 193, 195.

IsBvis, 195, 196.

lamellosa, 197.

norvegioa, 183, 193, 194.

ostreoides, 193.

Stella, 203, 204.

striata, 193, 195.

strigata, 202, 203.

tenuis, 19G.

turbinata, 189.
Orbiculae, 203.
Orthis

anomioides, 152, 153.

decoUata, 129.

detruncata, 128, 129.

hmifora, 149.

neapolitana, 131.

oblita, 104.

pera, 141.

truncata, 104.
Ostrea glomerata, 43.

Pachyrhynchus roseus, 116.
Palliobranchiata, histology of, 19.
Pallustra, 205.
Patella, 186.

anomala, 183.

distorta, 183.

kermes, 188.

unguis, 206.
Pecten, Terebratulina canccllata

attached to, 36.
Pectunnulus glycymcris, l-JO.
Pedicellin», 202.
Pholas, 62.
Pinna, 185, 205.

unguis, 207.

unguis, seu lingua, 206.
Platidia

anomioides, 152.

Davidsoni, 154, 155.

seminulum, 1.52, 153.

(Morrisia) anomioides, 152.
Platydia, 4, 106, 152, 230.

anomioides, 33, 54, 140, 149.
152, 154, 180, 234.

Platydia

Davidsoni, 154, 15.5, 156, 180,
234.
Platydiae, 108.

Platydiform stages, 5, 107, 110.
PlumateUa, 48.
Posidonia, 147.
" Poulette de la Tartarie," 81.
Productidffi, 188.
Produotus, 118.

Pulmoniferous Gasteropods, air-
breathing organ in, 199.

Ehynchonella, 4, 8, 161, 230, 234.
cEelata, 171.

cornea, 163, 171, 182, 234.
Doderleini, 33, 163, 172, 173,

182, 234.
Grayi, 163,169, 182,234.
lineata, 169.

lucida, 16, 33,163, 168, 182,234.
nigricans, 163, 165, 169, ]70i

171, 182,234.

, var. pixidata, 54.

, var. pyxidata, 170, 171,

182.
psittacea, 163, 164, 165, 166,

167, 168, 169, 172, 181, 182-
, var. Woodwardi, 33,

168, 182, 234.
pyxidata, 171.
sicula, 171, 172, 182.
spinosa, 173.
subplicata, 169.
Woodwardii, 168.
EhyuchoncUidaj, 4, 163, 166. 200,

230, 234.
Piostrum anatis, 206.

Splanchnoocele,or visceral cavity. 21i).

TerebratcUa,, 4, 5, 75, 230, 232.
bilobata, 232.
Blanfordi, 33, 75, 83, 232.
Bouchardii, 81, 82, 232.
caurina, 79, 80, 81, 102.
chilensis, 91, 176, 232.
coreanica, 33, 75,81,82, 97,232.
cranium, 178.
crenulata, 94.

cruenta, 75, 87, 88, 89, 176, 232.
Cumingii, 97.
dorsata, 75, 76, 78, 91, 93, 94,

95, 99, 176, 232.
Evansii, 87, 89, 176, 232.

Terebratella
fibula, 98.
tlexuosa, 92.
Frielii, 75, 92, 177, 232.
frontalis, 33, 75, 86, 95, 96,

176, 232.
inconspicua, 84, 85, 86, 176,

232.
Kocbii, 178.
Labradorensis, 102.
Lamauoni, 81, 82, 232.
lupinus, 176, 232.
magellanica, 176, 232.
Mariae, 33, 75, 89, 90, 176, 232.
miniata, 81, 82, 232.
neapolitana, 131.
oblita, 104.

oecidentalis, 79, 80, 81.
pulvinata, 75, 81, 90, 91, 177,

232.
rubella, 113.
rubicunda, 75, 83, 84, 85, 86,

176, 232.

rubiginosa, 75, 91, 177, 232.

rubra, 118.

sanguinea, 84, 109, 232.

septata, 90.

Sowerbyi, 176, 232.

spitzbergensis, 33, 75, 83, 84,

177, 232.
suffusa, 91, 94.

transversa, 75, 79, 80, 81, 102,
177.

, var. caurina, 177, 232.

, var. oecidentalis, 177, 232.

truncata, 104, 120.

zelandica, 87, 232.

(Magas) Evansii, 88.

(Terebratula) cruenta, 88.
Tercbratellfc, 110.
Torebratelliform stages, 107.
Terebratellinffi, 4, 75, 230, 232.
Terebratula, 6, 161, 199.

abyssicola, 34, 37.

affiuis, 9.

algoensis, 120, 123.

angusta, 34, 68.

aperta, 128.

appressa, 152, 153.

arctioa, 10.

aurita, 17.

australis, 41, 43, 62,71.

Bartletti, 14.

bilobata, 76.

Blanfordi, 83.

INDEX.

247

Terebratulu

Bouchardi, 73, 176.
californiana, 112.
californica, 112.
cancellata, 35.
canreua, 79.
cai)cnsis, 119, 122.
capsula, 1.50, 234.
caput-serpentis, 17, 18. 19, 20.
(attached to Oculina) 21,
(arms) 22, 24, 25, 20, 28, 00,
S3,
cardita, 12S.
caiirina, 79.
ceruica, 16.
Chemnitzii, 18.
chilensis, 70, 77, (arms) 79,

199, 201.
cistellula, 139, 140.
cogiiata, 121, 122.
cordata, 151.
coreanica, 73, 81, 170.
eostata, 18.
cranium, 01, Q2, 00.
crenulata, 94.

cruenta, 87, 88, 89,108,120, 170.
cubensis, 12, 13, 14, 16, 61.
Cumingi, 117.
euueata, 141, 142.
Dalli, 17, 33, 68, 201.
Davidsoni, 9, 33.
deeollata, 107, 128.
deutata, 43.
detruiicata, 107, 128.

dilatata, 49, 51, 52, 72.

dimidiata, 128.

diphya, 8.

disculus, 104.

dorsata, 70, 77, 79.

emargiuata, 18, 20.

er}'throleuca, 109, 115.

euthyra, 61, 63.

eximia, 50, 51.

fibula, 98, 99, 117.

flavesccns, 49, 41, 43.

flexuosa, 77, !)2, 93, 94.

floridana, 50.

Fontancana, 5n, 51, 71.

t'routalis, 8l>.

(iaudichaudi, 5(i, 51 .

Gervilki, 18.

glabra, 01.

globosa, 4'.l, 50, 51, 53, 54, 71.

Grayi, 54.

incurva, 41.

SECOND SERIES. — ZOOLOGY,

Terebratula

japouica, 34.
Kochi, 112.

Labradorensis, 102.
lenticularis, 41. 52, 53.
lunifera, 140, 149.
lupiuus, 70, 77.
Malviua;, 100, lol.
ilariaj, ^S.
miniata, 73, 176.
minor, 9, 10.
Moselcyi, 1 1 .
monstruosa, 108.
Murrayi. 39.
Xatalensis. 123.
nueleata, 1 0.
occidentalis, 55.
patagonic.a, 99.
pectinitbrmis, 129.
pelovitana, 50, 57, 58.
pera, 141.

physema, 5o, 51, 71.
picta, 114.
pisum, 123.
psittacea. 16.3.
pubescens, 17.
pulcheUa, 109, 110, HI,
pulvilla, 90.
pulvinata, 90.
quadrata, 18, 20.
recurva, 43.

rhombca, 77, 93, 94, 177.

rosea, 1 10, 117.

rubella. 113.

riibicundii, 1 19, 120.

rubra, 87, 119, VJn.

sauguinea, 87, 108, 109, Ho,
111,

sanguiuolenta, 108.

semiuula, 132.

seminuhim, 152, 153, 234.

scptata, 56, 57, 58.

septeutrionalis, '2S.

septigcra, 50, 58.

Soldanianu, 141, 142,

Sowerbyii, 76, 77, 79.

sphenoidea, 12, 13.

spitzbergensis, 63.

striata, 18.

subquadrata, 14.

subvitrea, 61.

tenera, 66, 67.

transversa, 79.

, var. caurina, 55.

trigona, 40.

VOL. IV.

Terebratula

truncata, 104, 108.

tuberata. 39.

tulipa, 116, 1 17.

unguicula, 25.

unguis, 116, 117.

ungula, 128.

urna autiqua, 128.

uva, 10, 16, 111.

venosa, 50.

vitrea, 6, 9, 13, 14, 37, 61,

, var. minor, 9, 10.

, var. sphenoidea, 1 2.

Wyvillii, 15, 07.
Zelandica, 87.
(.Vrgiope) cistellula, 139.

( ) cuneata, 141.

( ) decoUata, 129.

( ) neapoUtana, 131.

(Bouchardia) Cumingii, 97,

169.

98.

-) fibula, 97, 98.
-) tulipa, 116.
-) cognata, 121.
-) Dcshayesii, 122.
-) Lamarekiana, 124.
-) pisum, 123.
-) rubra, 119.

(-

(Kraussina) ruljra, 55.

(Magus) creuulata, 94.

(Megerlia) truncata, 103.

(Morrisia) anomioidcs, 152.

( ) Davidsoni, 154.

( ) lunifera, 149.

(Terebratella) Coreanica, 81.

( ) Labradorensis, 102.

( ) ilagellauica, 76, 93.

( ) sauguinea, 109.

( ) suffusa, 93.

( ) transversa, 79.

(Terebratulina) radiata, 34.

(Theoidea) mediterraneum, 157.

^Waldheimia) cranium, 02.

( ) dilatata, 50.

( ) flavescens, 41.

( ) globosa, 50, 53, 1 12.

( ) Grayi. 54.

( ) picta, 114.

( ) pulvinata, 90.

( ) septigera, 5().

Terebratulie, 107, 114, 151.
Terebratulidaj, 4, 5, 7, 144. 165,

100,167, 168,209,230,231.
Terebratulina, 4, 17, 208, 230, 231.

abyssicola, 37, 38, 70, 231.

aurita, 231.

34

248

INDEX,

Terebratulina

australis, 228.

CaiUeti, 26, 27, 70, 231.

caneellata, 35, (adhering to valve
of Trigonia) 36, (attached to
Area, Carduim, seines of Ci-
daris, Pecten) 36, 70, 231.

caput-serpentis, 8, i:'>, 17, 18,
19, 22, 23, 24, 25, 26, 27, 28,
29, 33, 34, 37, 38, 39, 05,
84, 231.

, var. emarginata, 17, 70.

, var. japoniea, 34.

, var. meJiterranea, 17, 20,

70, 23] .

, var. septentrionalis, 28.

, var. iiiiguiculata, 25, 70,

231.

Chemuitzii, 231.

cornea, 18.

costata, 231.

Crossii, 33, 34, 68, S3, 231.

cubensis, 27.

Cumingi, 33, 34, 37, 70, 231.

Dalli, 33, 68.

Davidsoni, 36.

emarginata, 231.

GerviUei, 231.

incerta, 38, 70, 231.

Japoniea, 25, 33, 34, 37, 38, 68,
231.

Murrayi, 39, 70, 231.

pubescens, 231.

quadrata, 231.

radiata, 33, 34, 35, 70, 231.

retusa, 231.

septentrionalis, 21, 24, (geo-
graphical range) 28, 29, 30,
04, 69, 70, 231.

spatula, 231.

striata, 18.

trigona, 40, 70, 231.

tubcrata, 39, 70, 231.

Terebratulina

unguicula, 25.
AVyvillii, 32, 08, 201.
(Agulhasia) Davidsoni, 36, 71,
236.
Terebratulina?, 4, 5, 143, 230, 231,

232.
Teredo, 62.
Tlieoidea

mediterranea, 156, 157, 160.
spoudylea, 156.
testudinaria, 156.
Thecidiidse, 4, 156, 160, 230, 234.
Thocidium, 4, 155, 156, (section of)
159, ("oral arms" or labial ap-
pendages) 161, 230, 234.

Earretti, 156, 102, 181, 234.
mediterraneum, 156, 157, 158,

161, 162, 181, 234.
Moorii, 162.
Perrieri, 160.
recurvirostris, 160.
spondyloa, 156, 234.
testudinaria, 156, 234.
Iriangulare, 162.
vermiculare, KiO.
Tretenterata, 4, 182, 183, 230, 234.
Trigonia, Terebratulina caneellata

adhering to a valve of, 30.
Trigonia Lamarckii, 36.

Uncertain species, 16, 37, 67, 90, 99,
111, 147, 188,204,220,228,231,
235.

Vermes singularissimus, 186.

Waldheimia, 4, 40, 230.

australis, 41, 42, 43, 48, 59, 60,

61, 65, KiO, 167, 231.
californiana, 112.
californica, 112,
caput-serpentis, 04.

Waldheimia

cranium, 22, 24, 41, 57, 61, 62,

63, 64, 65, 66, 67, 113, 151,

152.
dilatata, 231.
eximia, 231.
euthyra, 62.
flavescens, 19, 23, 24, (valves)

42,43,44, (sect.) 45, 46,47,

(viscera) 48, (genitalia) 48,

49, 54, 62, 65, 71, 125, 231.
floridana, 5, 13, 41, 57, 58, 59,

60, 61, 232.
Fontaineana, 54, 231.
Gaudichaudi, 231.
globosa, 231.
Grayi, 33, 41, 54, 55, 56, 72,

si, 232.
incurva, 231.
kerguelenensis, 41, 53, 54, 72,

171, 232.
lenticularis, 41, 52, 53, 54, 72,

232.
Patagonica, 90, 100.
]ihysema, 231.
picta, 114, 115.
Eaphaelis, 33, 41, 58, 59, 72,

83, 232.
septigera, 41, 56, 57, 58, 59,

72, 110, 232.
venosa, 41, 49, 50, 51, 52, 53,
54, 90, 96, 100, 112, 231.

, var. dilatata, 7

•a, 72.

WyviUii, 16, 41, ()6, 67, 72, 201,

232.
(Macaudrevia) cranium, 41,44,
61, 72, 232.

( ) tenera, 41, 66, 72, 232.

(Terebratula) diiatata, 52.
Waltonia

Valeneiennesii, 84, 85.

Zeilleria, GO, 1U7.

PRINTED BX TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

Thos Davidson

Trans Linn Soc.S'er 2 Zool Vol IV Pi,

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17-18.1. ARCTICA- '19. L.CKRNICA. ^0-21 L.BARTLETT!

HanKart

Thos Davidson

Irans Linn. Soc Ser.2 Zool A-bL 1V.Pl.2.

TEREBRATULI^LC.

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15-16. L.SUBQUADRATA. 17-22. L.SPHENOIDEA. 23-23!' L.(or-TEREBRATULINA)DALLI.

West, Newinan . imp .

Thus Davidson

Trans Linn Sou, SjiR 2 7.oo\. Vol.IV.Pi,3

TEREBRATULIN,^:

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4-6. T. CROSSII. 7-11. T JAP01-^[ICA. 12. T. CAPUT- SEEPENTIS .

llanliart-

unp

Ihos Davidson

Trans Linn Soc Skr 2, Zooi. Voi. IV Pi,.^.

8

c

teri:bratui.in>f:

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Kan hart ir

.mp

Tho'. Ddvidson

Trans Linn Soc.Sf.r 2.Zool Yol.IV.Pl.5

3i

38
A'

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Z 5 6

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32-34^ T CAPUT-SERPENTIS. 35-37^ T. GAP-SERP. rar. MEDITERRANEA 38-40.T CAPrSERP wUNGUTCULATA
HammcBllitl, 41-42^ T. CAILLETL 53-53^ T CUMIN Gl . 54.T, ABYSSICOLA . H.nEart imp

7 iios Davidson

Trans Linn Soc.Ser2.Zool VolT/PI.G.

TEREBRATULIN^ .

/

V

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l-8> TEREBRATULINA CANCELLATA. 9-14. T. RADIATA. 15 -]7. T. MURRAYI.
18-20 T. TUBERATA 21-22. T. TRIGONA 23-25<^ T '?) INCERTA

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Tims Davidson

Trans Ljnn SocSerZ Zool Vol IV Pl.7,

TEREBRATULINyt:

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e-ig.Vi'AI.DHEIMIA FLAVESCENS

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lilllS DdVJilaoU

Trans Linn.Soc.Skr 2 ZoolVol.IV Pl.-

•w.^-

TKRKBRATUI.IN/E

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1 5.WAI.DHK1M1A VENOSA. 6 W, KONTAINEAN A

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Trans, Linn 5oc, Ser 2.Zool,Vol IVPl 9.

rEREBRATULIKj^

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1 WALDHEIML^ '.^ENOSA vai- L'T^ATATA. 2-13" W, LENTICULARIS.

\Vcs:.Newmdii i Ca mic

Thos Davids

Trans. LiNN.SoaSEH,2 ZoolVol.IV.Pl, 10.

TEREBRATUIJN.*:,

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1-3 WALDHEIMIA GRAYI. 4-. W. GRAYIvov-. TRANSVERSA,

.S- 6, W. WYVILLII. 7 -:7 W. KERGUELENENSIS

West,Newmari imp

Thos Davidson

Trans. Linn Soc Ser.2.Zool,Vol IV.PlII

TEREBRATULIRC

r

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Van Iters on litii

1 -10, WALDHEIMIA SEPTIGERA. Jl-13. W. RAPHAELIS.

Weei , Ne

i:uip.

Thos Davidson

Tkans LiNN.Soc Ser 2. Z001..V0L IV.Pl.]2

TEREBRATULINyF.

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1-5. WALDHEIMIA PLORIDANA.
(3-10. W (.MACANDREVIA) TF.NE-RA. 11-23 .W. IMACA>1DREV1A) CRANIUM

uannarl imp

Thos Davidson

Tran,'5 Linn Soc S-er.Z.Zool.Vol IV.Pl.13.

./

tkrrbratulina;

VentraL
view

Dorsal '' -1 «

nen- .r\

y

TEREBRATELLIN.iE,

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Hammond iilii

1-2.WALDHEIMIA (MACANDREVIA) CRANIUM
3-9.TEREBRATELLA COREANICA . ( 5.= T.MINIATA Gould 8-9^= T BOUCHARDI,Z)»k)

liantart: imp

Tlios Davidson

Trans Linn Soc. Ser2. Zool Vol IV Pl.14.

TEREBRATELLIN.fl-.

V'

w

I:

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f. ^ iS^:>

^b

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^

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\-.n kei-soii liUi

1.-8. TEREBRATELLA CRUENTA
9.-19, T. DORSATA 20,-21'' T."LUP1NUS"

Wcsi.Npwid.'in ii:i

Thos, Davidson

Trans Linn Soc Ser2. Zool Vol iV. Pl,15.

TEREBRATELLINiE

\

5 y^

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5'

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^^

10°

J^

"/^

t?

l'=in Itcrson lith

1,-8? TEREBRATELLA FRONTALLti 9,-12. T, BLANKCKni
13,-14, T MARM2. 16,~29. T. RUBICUNDA

West, Newman imp

Tlios Davidson

Trans Linn, Soc.Ser,2. Zool,Vol.IVPi...16.

TEREBRATELLIN/S,

Ml

J

/>?

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^'

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10"

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1. b, TKHliBRATKt.l.A SPlTZBKPuGENSIS. 6r9. 1' TRANSVERSA.

iG; 12, ■;■ -r KA!^ S VERSA v«/-. CAURIUA. ISrlt, T THANSVE.R3A vo.- OCCIDENTALIS. 15, T PIJLVTNATA,

Vanhcrsonhih 16,- 17" T(?) FRIKI .1 ! - . 18, 18°^ M.( ' ) LABRADORENSIS. 19, T, RUBIGINOSA West, Newmim, ,n,p

Thos . Davidson .

Trans.Linn.Soc.Ser 2. Zool Vol.TV. Pl 17.

TEREBRATELLIN/£.

1-5. MAGASELLA FLEXUOSA. 6-8* M FLEXUOSA var RHOMBEA. 9-lL M. CRENULATA.
12-13* MPATAGONICA. 14-15 M , SUFF USA. 16 l?'^ M ALEUT! CA 18-B M ADAMSI .
M.cWi,tK 20-22 M.GOULDI. 23-32. M. CUMINGI. 33.MCUM1NGI var. FIBULA. '•'">'"" "^-

Tlios DawdscTTi

TFiANs.LiNN Soc.Ser-2. Zool.Vol IV Pl. 18.

TEI-lEB.RATT£Xi.lKyF.

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Mi:GERi,INj£.

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14-

i^

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5. TEREBF^ATULINA or MAGASELLA MALVIN.-?;

Mjntern imp .

6-3 LAQUEUS CAL170RNICUS. 10-13'' L. CALIFORNICUS VAR.VANCOUVEFUENSIS 14— IB.L.PICTUS.

Thos Davidson

Trans . Linn. Soc, Ser

VPl.19.

MEGERLIN^.

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^

^:

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Vanltersonluh ^'5. LAQUEUS RUBELb J £ . 6.-7^ L. SUFFUS'jS. W.^.Ne»n^m»

8-10'^ MEGERLIA JEFFREYS!. 11t20,MTRIINCATA.21722, M TRUNCATAvarM0NSTRU0SA.23r26,M."WILLEM0KSl.

Thos Davidson -

Trans - Lxkn. Soc. Ser,2. Zool.Vol.IV", Pl, 20.

\3'

'^4

3"

^mw

laEGERLIN^

A

J -^

^1

-f

/ %

-'iiiito*'

1-8. MEGERLIA SANGUINEA. 3-11. M SANGUIN FA var PULCHEL'^A,sow. 12 12'' M.SANGUINEAvar.REEVEI.xiav

McWihlK 13-18 BOUCI-lARDlA ROSEA. . MiTAerr. >mp .

19-23. I\RAUSSINA RUBRA . 24 -26 . K COGNATA. 27-30 K.COC-NATA var? 31-31*^ K DESKAYESl. .

Thos Davidson .

TRA^^s . LiNN . Soc . Ser. 2 . Zool . Vol , N . Pl - 21 .

KRAUSSININ^^

1-4 KRAUSSINA PISuM. 5-I3.K.ATK:

il^Ok^jM

NI

"Micliae^ litK.

7-ll.K,(MEGERLlNA) LAMARCKIANA, 12-14 .K,(M).DAVIDSONI.

15-13. PLATYDIA AN OMIOlDES =20-22. T. SEMINULUM. 23-27. P DAVIDSONl

28-23 GA/VYNIA CAPSULA 30-36 ARGIOPE DECOLLATA,

ilir-xerrv imp.

Thos Davidson

Trans. Linn. Soc-Ser, 2 Zooi, Vol IV. Pl 22.

ARGIOPia«

"^

V--:i

,^~

.35"

;.Sc-^

-'?^.

CrowtKer lith

I—* CISTELLA CISTELLULA. 6-6 . C. LUNJFERA. 1—1^ C. WOODWARDIANA. Mmtem.mp.
8-24. C.NEAPOLITANA=25-2S'' C. B]PLir.^.TA 2G-27 C KOWZ-iEVSKIl. 35-36. C.BARRETTIANA.
30-34. C.CUNE ATA. 28. ARGIOPE GLOBULIFORMIS. 29. A. BARROISI .

Thos Da-'vidson

THKOIWxDjE,

7h.,:;3. LIN^^Soc Ser,2 Z00L.V0L.lVpL.2y,

A^- \'''

!-?„ aSTOLUVBAPJffiTT.'ANA. ('C.RUBROTING'ja;. 3-4. C. SGHH/iMK:
V'a,i, lt<j,->,--.,„.r.,, '/-Qcx G. ANT1I,1,AKUM

9-ll,THECrD!UM BARRET I'l . J2-.22, T. MRDITBRRANEUM ,

C LU'J'KA

West, Kftwmazi, imp

Thos Davidson

Prans Linn, Soc.Ser.2.Zool.Vol.IVPl,24'

RHYNCHONilUjID^

iiliii

Van Iters on, liLh

l-ll, PJ^TIMCHONELLA PSITTACKA. 12-13? R PSITTAGEA, va.r. WOODWAKDI.
14-15V R -LUCIDA. lG-19, R-NIGRICA'NS 20^20^ R NIGRICANS, varPYXIDATA.

"(Ifest, liewman ucp

Fiios Davidsori-

Tr..^s. Linn.Soc.Ser.2. Zool.Vol.W Pl 25

F.HYNCHONKLLiD/r:

1-1': RH"YNCHONELLA GRAYl 2-4 R.CORIJEA 6 R .31CULA uossil) 14-15 P. DODEFILEINI .

e-1-3- ATRETIA GNOMON. J6 17^ A.BRAZIERI.
18-26. DISCINA STRIATA

Mint em. imp

Thos Davidson

iJ

•m

'jj\s . LiNX' . Soc . Ser. 2 . Zocl . Voi. . N. ?l . 2'6

DISClNLD.4i

V '

.iafe^'

.•*i^

'^'m^mm^

-?>, t

24

"•¥

^""^m--^

' x

-'■' tr-

t>!>wt}jp.r lilt..

i

1-8 DISCINISCA LAJVIELLOSA^ 3
AKTICA, 23-2G E
31,3FDISC]NISCA ANTlLLARUlvI

6-22 D. ATLAKTICA, 23-2G D CUMINGl. 27-30. D, STELLA

L. L-^VIS. 12-17^ D. TENUIS

Jern inu> .

Thos Davidson.

Trans .Linn . Soc . Ser. Z . Zool .Vol . IV. Pi.. 27

CRANIIDvE

i^mc

'€'

%

"•^

r ^.i*.

Pi^.

1-9 CRANIA ANOMALA. 10-11 C JAPONICA

12. C. POURTALESI. 13.C.SUE3SI. 14-2S C TURBIl'^TA.

Mini'wrn imp.

I'hos Da'adson

Trans Linn. Soc.Ser2. Zool Voi.,lVFL28.

CRANIin^^ & LINGULin^.

l.-l"' CRANIA TIJP.BINATA vo/- RINOENS.

2:4, GLOTTIDIA ALBIDA 0^6° G PALMERI. 7,-11, G AUDEBARTl Brad, (=LINGULA PYRAMIDATAStosos) 12, G SEMEN, 13 GANTlLUvRUM

14,-15, LIN GULA TUMIDULA. 16,-L LEPIDULA. 17-18<^ L REEVET, UXLADAMSl

vw,h«-sonl,ih 20,-21":' L EXIT .STA. 22, L, HIRUNDO, 237-24=^ L JA5PJDEA. 36, L 3MAi<AGDlNA Wc....N™„.«.. ■,..„.

i'hos DavidijO:

Trans I. inn Soc Sk.h,2 Zool Vol 1VPl.2B

LlNGULID^ti

Va^ ItersonJUth.

1-8^L1I1GULA ANATINA
9-]0,L,A1''F1:NIS. ll.L, MUHPHIANA IE-13,1. HIANS

\fet.Newinaji5:Ct. mip

Thos. Davidson

Trai-is, Linn. Soc. Ser. 2 . Zool . Vol.III. Pl.30.

1-3,LINGULAMURPHIANA, 4.-5. LlNGULA.Sp > (Yeddo Bay) 6 L A1\IATINA.
7-11, Development GLOTTIDIA(L).AUDEBARII, Brod.. = LINGULA PYRAMIDATA.Stimps (afierWK Brooks).

12-14. Structures GLOTTIDIA AUDEBAPJl, (After H.G Beyer). M,nt.rr, ,mp

2nd Ser. ZOOLOGY.]

r

[VOL. IV. PART 2.

THE

TRANSACTIONS

OF

U^Jr- out ^RlL '^u^.'C.x/-^

THE LINNEAN SOCIETY OF LONDON.

A MONOGRAPH OF RECENT BR ACHIOPOD A.-Part II.

BY

THOMAS DAVIDSON, LL.D., E.R.S., F.L.S., F.G.S., &c.

LONDON:

PRINTED FOR THE LIKNEAN SOCIETY

BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W.,
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July 1887.

2nd Ser. ZOOLOGY.]

[VOL. IV. PART 3.

Dee.

THE

''~)0

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OF

THE LINNEAN SOCIETY OF LONDON,

A MONOGRAPH OF RECENT BRACHIOPODA.-Part III.

BY

THOMAS DAVIDSON, LL.D., F.R.S., F.L.S , E.G.S., &c.

WITH TITLEPAGE, CONTENTS, AND INDEX.

ir ^jm!e^

LONDON:

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SOLD AT THE SOCIETY'S APARTMENTS, BURLINGTON-HOUSE, PICCADILLY, W.,
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0

16

0

0

15

0

0

9

0

0

3

9

0

7

6

0

2

3

0

2

3

0

10

0

0

7

0

0

7

6

0

5

0

0

2

6

0

4

6

0

6

0

1

0

0

0

5

0

0

7

6

0

2

0

2 14 0

3 2044 106 309 321

Date Due

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