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A 


HISTORY 


BWITISH MOLBLUSCA, 


AND THEIR SHELLS. 


BY 


PROFESSOR EDWARD FORBES, F.R.S., 
AND Ce Ae ia 
SYLVANUS HANLEY, B.A., F.L.8.7 


OF WADHAM COLLEGE, OXFORD. 


VOLUME II. 


INCLUDING THE REMAINING FAMILIES OF BIVALVES, THE 
PTEROPODA, AND THE GASTEROPODA AS FAR AS 
IANTHINIDA. 


LONDON: 
JOHN VAN VOORST, PATERNOSTER ROW. 


~ M.DCCC.LIII. 


a \- (89 pa. \ G44 
re HB\~ 55) pe 


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ethan 


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Jor dates ace WN Adamaynr’@ 
Aneliw, 2. Nalurguel,. \8S80,2, 
PASS 4 Vest, 2, ’ jo4 , 


LONDON: 
Printed by SamuEL BentLEY and Co, 
Bangor House, Shoe Lane. 


a e 


CONTENTS OF THE SECOND VOLUME, 
EXHIBITING THE FINAL CORRECTIONS AND ADDITIONS. 


Species of questionable indigenousness are printed in italics; spurious and 
unrecognized species in nonpareil. The addition of (A. i.) to a species refers the 
reader to the first Appendix, or Supplementary Notes on the Acephala, in the 
Second Volume, (A. ii.) to the Appendix at the end of the work. 


PAGE PAGE 
ACEPHALA LAMELLIBRAN- MonracutTa 5 F ae yt 
CHIATA continued. M. ferruginosa (a. 1i.). 6 OU 
CARDIADE . ; : ; 1 M. bidentata : see hs) 
Gate 9 M. subsiriata. : one Uh 
TURTONIA . P . . 80 
C. aculeatum 4 5 5 
: T. minuta (4. 1.) . : 5, till 
C. echinatum 7 : 
Genetica 11 KELLIA : ; ‘ G4: 
: K. suborbicularis ; Stirs 
C. edule 15 
VS UI OHED, og 4 : 5 ee! 
C. nodosum PAP 3 
- Tellimya lactea . 5 GL) 
C. fasciatum 25 Tellimya tenuis ; esl a9 
C. pygmeeum (A. ii.) . 29 LEPTON ye, SOT 
C. Suecicum ; . 33 L. nitidum (as Kellia nitida) 92 
C. Norvegicum . . - 35 var. convexum (A. ii.) . 102 
C. Grenlandicum —. - 39 L. squamosum . ; . 98 
C. serratum ¢ > 4 Ri) |) : Ap 
ee oe me L. Clarkiz (A. ii.) 
Co mentexiun = e > 40 GALEOMMA . 2 : 104 
LUCINIDE . ; ; way G. Turtoni. Z 3 . 105 
Lucina (Ai)  . . +» 43 | CYCLADID POD 100 
L. borealis . : P eG CycLAs ; : SO 
L. spinifera . : . 49 C. rivicola . 5 : 6, IIL 
L. divaricata . : 7 oOo C. cornea . j Z 5 WB 
L. flexuosa 2 : . 54 C. caliculata . : ls 
L. leucoma . : 3 5 Ey, C. lacustris ; , 5 NG 
L. ferruginosa . : 5 GU PIsIDIUM . : : - 120 
L. orbicularis . » 62 P. obtusale : say mcr lee 
L, tigrina : , . 64 P ill 12 
DIPLODONTA ; : . 64 P. Pee - ; ee 
D. rotundata . 5 5 (5 Ps sues / 196 
KELLIADZ . : : =. 69. P. pulchellum . - - 128 


vi 


Pistprum continued. 


P. Henslowianum 
P. amnicum 


UNIONIDA . 
UnNIo 
U. tumidus 
U. pictorum 
U. margaritiferus 
U. Batavus 
ANODONTA 
A. cygnea . 


MYTILIDZ . 
DREISSENA ; 
D. polymorpha . 
MytTiuus 
M. edulis . 
M. bidens 


M. crenatus 
M. Africanus 


Mopi0La 
M. Modiolus 


M. phaseolina (A. ii.) . - 186 


TABLE OF 


PAGE 


5 lant 
510838} 


. 136 
. 138 
. 140 
. 142 
. 146 
. 154 
. 155 
. 155 


. 162 
. 163 
- 165 
. 168 
. 170 

179 

180 
- 181 
. 181 
. 182 


M. tulipa . . 187 
M. barbata . 190 
M. Ballii . . 192 
CRENELLA . 194 
C. discors . - 195 
C. marmorata . 198 
C. nigra . 202 
C. costulata . 205 
C. rhombea . 208 
C. decussata . 210 
C. faba (A. ii.) . : 
Lithodomus aristatus . 5 Pale? 
L. fuscus . 213 
ARCADE aA: 
NvucuLa . 214 
N. nucleus 5 P15) 
N. nitida . a Pailte} 
N. radiata a0 
N. decussata 5 Pat 
N. tenuis . a 220 
N. argentea 218 
LEDA . 226 
L. caudata . 226 
L. pygmea : 230 


CONTENTS. 


LEDA continued. 
L. Montagui 
L. oblonga 
L. truncata 
ARCA 
A. tetragona 
A. lactea 


A. raridentata (A. ii.) . 


A. barbata . 
A. Now 
PECTUNCULUS 
P. glycimeris 


AVICULACE 


AVICULA 

A. Tarentina 
PINNA . 

P. pectinata 


P. carnea 
Perna alata 


OSTREADZ . 


Lima A 
L. subauriculata. 
L. Loscombii 
L. hians 

PECTEN 

. varius . 

niveus . 

. pusio 

. striatus 

. tigrinus 

Danicus 

P. glaber. 

. similis . 

maximus 

. opercularis 

. Islandicus 

P. Jacobeeus . 

OsTREA 

O. edulis 


O. cristagalli 
O. frons 


ANOMIA 
A. ephippium 
A. aculeata 
A. Patelliformis . 
A, striata . 


ys vr 


PAGE 


TABLE OF 
PAGE 
ACEPHALA PALLIOBRAN- 
CHIATA, OR BRACHIO- 
PODA ‘ y ‘ 5 oa) 
TEREBRATULID& ‘ . 343 
Hyporuyris : - . d44 
H. psittacea “ - . 346 
TEREBRATULA . : . 349 
T. caput serpentis . . 353 
T. cranium 5 : 5, Bar 
Anomia terebratula . . 358 | 


ARGIOPE (AS MEGATHYRIS) . 359 
A. (as M.) cistellula (A. ii.). 361 


CRANIADA . : : . 364 
CRANIA 5 > : . 365 
C. anomala 5 : . 366 
Orbicula striata ‘| . 368 


SUPPLEMENTARY NoTES ON 


ACEPHALA . : - . 369 
TUNICATA . ; - . 369 
Sidnyum turbinatum . . 369 
Botryllus rubens : . 370 

“* virescens . : . 370 

“ castaneus . : . 371 
Botrylloides radiata. 5 Ovi 

= ramulosa 9) . 372 
Ascidia sordida . : . 372 
“ albida : : . 373 

“* depressa . : . 373 

“ elliptica . : . 374 

“ pellucida . F . 3/4 
Molgula arenosa . : . 374 


LAMELLIBRANCHIATA . 375 


Cynthia coriacea 6 . 375 
Cyprina Islandica : . 375 
Turtonia minuta ; . 375 
Xylophaga dorsalis. . 376 
Clausina . : ; . 376 
PTEROPODA - 5 5 GTi 
HYALEA ; 4 5 . 379 
H. trispinosa 2 : 380 
SPIRIALIS.. ° . 382 


S. Flemingii (4. ii.) . . 384 


CONTENTS. 


SpPIRIALIs continued 
S. M‘Andrei 
S. Jeffreysii 


GASTEROPODA PROSO- 


BRANCHIATA 


CHITONIDA® 
CHITON 
C. fascicularis 
C. discrepans 
C. Hanleyi (A. ii.) 
C. ruber 
C. cinereus 
C. albus (A. ii.) . 
C, asellus 
C. cancellatus 
C. levis 
C,. marmoreus 
C, punctatus 


PATELLIDA® 
PATELLA 
P. vulgata . 
P. athletica 
P. pellucida 
P. intorta : . 
ACMA 
A. testudinalis 
A. virginea 
PILIDIUM 
P. fulvum . 
PROPILIDIUM : 
P. Ancyloide (A. ii.) . 


DENTALIAD A 
DENTALIUM . 
D. entalis 
D. Tarentinum 
D. semistriatum 
D. octangulatum - 
D. yariabile 


CALYPTRAIDA . 
PILEOPSIS 
P. Hungaricus 
P. militaris 
P. antiquata 
CALYPTR&A 
C. Sinensis 


vil 


PAGE 


vill TABLE OF CONTENTS. 


PAGE 
CALYPTR&A continued. 
Crepidula unguiformis » 466 
FISSURELLIDA . : . 467 
FISSURELLA . MEAG . 468 
F. reticulata : . 469 
F. nubecula 5 5 ay} 
PUNCTURELLA ‘ ‘ . 473 
P. Noachina : 5 . 474 
EMARGINULA 2 . . 479 
E. reticulata : : 5 Hla 
E. rosea. , : . 479 
E. crassa. ; 5 . 481 
HALIOTID 2 . ; - 484 
HaLiotis . ; 0 . 484 
H. tuberculata . : . 485 


TROCHIDA . 5 A . 489 
TROCHUS 5 6 6 . 489 
T. zizyphinus  . 4 . 491 

T. conulus : ; . 495 

T. alabastrum . h - 497 


T. granulatus  . : - 499 
T.millegranus . : . 502 
T. exiguus : : « 505 
T. striatus . . . . 508 


T. Montagui.. : . 511 


TrocuHus continued. 
. tumidus (A. ii.) 
. cinerarius 

. umbilicatus 

- Magus .- 

. lineatus 

. undulatus 


HHHHH HA 


- Helicinus 
T. pusillus (A. ii.) 


Margarita olivacea 


Trochus sanguineus (A. 


(as Margarita aurea) 
T. cinereus 
Turbo rugosus . 
Turbo castanea . 
PHASIANELLA 
P. pullus 
ADEORBIS 
A. subcarinata 
ScISSURELLA 
S. crispata . 


IANTHINID/E 
IANTHINA . 
I. communis (A. ii.) 
I. pallida . : ° 
I. exigua . 


PAGE 


ii.) 


BRITISH MOLLUSCA. 


CARDIADA. 


Tue Cockles, properly so called, form a very natural 
assemblage, presenting well-marked characters both of shell 
and animal. Their shells are of variable thickness, some- 
times strong, in other cases very tender, and are often sculp- 
tured in bold and striking relief. The furrows upon them 
are usually radiating, a feature which prominently dis- 
tinguishes them from the majority of shells in the last 
family, and the ridges are often ornamented by arched 
scales. The dentition of the hinge is very variable, often 
strongly marked, sometimes nearly obsolete. The pallial 
sinus is entire, corresponding to the structure of the mantle 
and siphons, the latter being distinct, but very short, and 
nearly sessile. Their bases and sides are fringed. The 
mantle is freely open in front. The foot is remarkable for 
its geniculated form and great size, enabling the animal to 
make leaps prodigious in proportion to its dimensions. 

Tsocardia is often included by authors in this family ; 
but, as we have already seen, it has much nearer affinities 
with Cyprina and its allies. The only British genus truly 
a member of the group is Cardium; one which, from the 
number, abundance, and beauty of its species, plays no un- 
important part in our marine fauna. The family connects 
the tribe last treated of with the Aelliade and Cycladide, 


VOL. Il. B 


2 CARDIADA. 


and is probably parallel with the Lucinide, which we are 
compelled to treat of in sequence. 


CARDIUM, Linnzus. 


Shell equivalve, more or less cordiform, oblong, or trans- 
versely ovate, usually inflated, closed or gaping posteriorly, 
longitudinally ribbed or furrowed in radiating fashion from 
the prominent beaks, rarely smooth; ribs often scaly or 
spiny; margin almost always crenulated. Hinge composed 
of two oblique primary teeth in each valve, and two remote 
lateral ones (in certain exotic forms the teeth become par- 
tially or wholly obsolete). Ligament short, external, con- 
spicuous ; pallial impression simple. 

Animal suborbicular, tumid, its mantle freely open in 
front, with plain, or, less frequently, fringed edges, conspi- 
cuously fimbriated in the neighbourhood of the two very 
short, slightly-separated siphons, the branchial one of which 
is always fringed at the orifice. Foot very large, cylindri- 
eal, geniculated. Branchial leaflets unequal, labial palps 
rather long and triangular. 

This great and very natural genus preserves its Linnean 
constitution, and every day receives accessions to its ranks 
from the researches of zoologists investigating distant re- 
gions. ‘The shells composing it are often remarkable for 
their elegance of form and brilliancy of colouring, and even 
our few British species are among the handsomest of our 
bivalve mollusks. There is a pleasure in investigating a 
group such as this, wherein we find not only the greatest 
variety, but also the greatest distinctness, and consequent 
certainty of specific determination. All that is known as 
yet of the animals of the several species goes to indicate 
that the features they present are as distinct as those ex- 
hibited by their shelis. 


CARDIUM. 3 


An assemblage presenting so many attractions has, of 
course, engaged considerable attention, and our knowledge 
of the extent and geographic range of the genus is conse- 
quently very advanced. There are, probably, very nearly 
two hundred species of Cardium in existence, and the 
localities of considerably more than half are well known. 
We find the great central assemblage of Cockles in the In- 
dian ocean, a region where about a third of the species 
are congregated. Around this centre the number of specific 
forms diminishes, though found in every sea. They are most 
plentiful everywhere within the tropics, and diminish as 
we proceed northwards and southwards; but some of the 
forms most prolific in individuals, and most gregarious in 
habit, are present in cold climates, and make up by abun- 
dance for the absence of variety. Of these, several are 
valuable articles of food; and it may be said of all the 
Cardia that they hold a high rank among mollusca both 
for nutritive qualities and excellence of flavour. The genus 
contains several remarkable abnormal forms; some of the 
most singular are to be found in the Caspian and other 
relics of the great Aralo-Caspian Sea, 


the demonstra- 
tion of which mighty inland ocean is among the finest dis- 
coveries of Sir Roderick Murchison. 

The geological distribution of this interesting group 
corresponds in extent with the geographical. Even in 
Paleozoic strata we find the fossilized remains of mollusks 
closely allied, if not belonging to Cardiwm. Inthe secondary 
rocks, even in their oldest members, well-marked forms of 
Cardium are not unfrequent, often singularly simulating 
those of existing times. During the later part of the 
secondary epoch and the beginning of the tertiary a group 
of half-ribbed Cockles, seemed to have been developed at 
the expense of ordinary forms, and to have dwindled away 


4 CARDIAD A. 


as they came near our own epoch, when but two or three 
allies of them are found. 

Cockles inhabit all depths of water, from the sea-shore 
at tide-mark to the deepest sea-beds as yet explored; but 
each species has a very definite range, and the succession of 
representative forms is as well marked bathymetrically as it 
is in horizontal space and in time. Sand, or sandy-mud is 
their usual habitat, and in it they lie buried, often in pro- 
digious numbers. 

Dr. Carpenter has examined the microscopic structure of 
the shell in this genus, and states that there is a tubular 
texture in the external layer, but little organic structure 
in the internal. 


C. acuteatum, Linnzus. 


Large, swollen, not solid ; ribs about twenty in number, rather 
depressed, armed with compressed prickles; their interstices 
almost smooth. 


Plate XX XIII. Fig. 1. 


Cardium aculeatum, Linn. Syst. Nat. ed. 12, p. 1122.—Penn. Brit. Zool. ed. 4, 
vol. iv. p. 90, pl. 50, f. 37—Da Cosra, Brit. Conch. p. 
175.—Donoy. Brit. Shells, vol. i. pl. 6 (not well).— 
Mont. Test. Brit. p. 77, and Suppl. p. 30.—Linn. Trans. 
vol. viii. p. 62.—Turr. Conch. Diction. p. 28.—Turr. 
Dithyra Brit. p. 180, pl. 13, f 6, 7.—Fiem. Brit. Anim. 
p- 420.—Brit. Marine Conch. p. 95.—Brown, Illus. 
Conch. G. B. p. 87, pl. 34, f. 1, 2, 3—CHEMN. Conch. 
Cab. vol. vi. p. 161, (in part) pl. 15, f. 156.—Po zt, Test. 
Sicil. pl. 17, £. 1, 2, 3—Woop, General Conch. p. 207, 
(not variety,) pl. 48—Dim1w. Recent Shells, yol. i. p. 
114.—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 397.— 
Puiippl, Moll. Sicil, vol. i. p. 50, and vol. ii. p. 837.— 
SowerBy, Conchol. Illustrations, Cardium, f. 28.— 
Hanu. Recent Shells, vol. i. p. 181.—RerxEVE, Conch. 
Iconica, Cardium, pl. 4, f. 17. 
ciliare, (YOUNG.) Penn. Brit. Zool. ed. 4, vol. iv. p. 90, pl. 50, f. 
39.—PULTENEY, in Hutchins, Dorset, p. 31.—Donoy. Brit. 
Shells, vol. i. pl. 32, f£. 2—Monrv. Test. Brit. p. 79.—Linn. 


” 


CARDIUM. 5 


Trans. vol. viii. p. 64.—Dorset Catal. p. 31, pl. 4, f. 1— 
Woop, General Conch. p. 209, pl. 49, f. 3, 4. 

Cardium parvum, Da Cosra, British Conch. p. 177. 

Encyclopédie Méthodique, Vers, pl. 298, f. 1. 


As the shape and parts of the present species most closely 
resemble those of the succeeding, to avoid repetition, we 
shall merely specify the particulars in which it differs. It 
is a light, thin, bulky shell, and of far more ample dimen- 
sions than the majority of the individuals of echinatum; its 
tumidity, too, is not so evenly disposed, there being a mani- 
fest, though not considerable, flattening of surface behind 
the usual site of the umbonal ridge, causing a slight angu- 
larity of curvature, preceding which is the chief convexity, 
whilst the swell in the species we are comparing it with is 
almost central, Its contour is far more angulated than in 
the small ordinary suborbicular type of the latter, but very 
nearly resembles the large variety of it which we have de- 
lineated in our engraving. Its ventral margin, however, is 
less arcuated ; its posterior lower angulation more decided, 
its hinder edge rectilinear or subretuse (thus biangulating 
the broad posterior extremity), and its anterior dorsal edge 
is rather more sloping, which gives a marked projection to 
the prominent umbones. The beaks seem less inclined for- 
wards; and the ligament is very large and elevated. The 
surface has but little lustre, but is not utterly dull; the 
number of ribs ranges at least from eighteen to twenty-two, 
which are often almost obsolete at the posterior extremity, 
and not merely, as in echinatum, diminished im size and 
elevation. They are rather less raised, too ; much flatten- 
ed on their upper surfaces, and armed with rather large and 
crowded spines; of which the hinder rows (whose prickles 
are generally the longest and largest) are sharp-pointed, 
straight, and somewhat lancet-shaped, or laterally compress 


6 CARDIADA. 


ed, enlarging at their bases parallel to the ribs ; the central 
series are similarly shaped, but bend posteriorward ; and 
the front ones, which are shorter, and more solid, are com- 
pressed (in the mature shell) horizontally (or at right 
angles to the ribs), and are either blunt-topped, or bend up- 
ward at their apices. The interstitial sulci, which are 
scarcely as broad as the ribs, are only delicately marked 
with very fine and regular-raised concentric striule, which 
are not developed in the immature examples, and conse- 
quently are absent from the umbonal region of the adult ; 
they are not at all flexuous, a character which affords a 
ready means of distinguishing this species from the two 
succeeding ones. The lateral teeth, particularly the front 
one, which is generally the more approximate, are very large. 

The external colouring is also of a less yellow cast than 
in the next species, being usually of a pale-brownish flesh- 
colour, with livid or rufous zones. The sides of the adult 
are always very unequal, the outline being then oblique, 
and the umbones much nearer to the anterior commence- 
ment of the shell. The British specimens appear generally 
more elongated than the Mediterranean ones, which 
are more orbicular, less flattened behind, and more fully 
weaponed. 

The young shell is less inequilateral and oblique, and de- 
void of any inferior angle at the hinder extremity. The 
dorsal line is much more sloping than in echinatum, ascend- 
ing slightly on the hinder side. 

A good-sized example will measure four inches in length, 
and three and a third inches in breadth. 

Poli states that the animal of this species is of a cinna- 
bar colour ; the foot long, subulate ; the bases of the tubes 
not fimbriated ; the last statement, however, is probably 
a mistake. 


CARDIUM. (6 


It is a remarkably local shell, and we believed it peculiar 
to the South Devon coast; it is stated, however, to have 
been captured also in Dublin Bay and Portmarnock in Ive- 
land, and in the Hebrides and Orkney Islands (Captain 
Brown), but has evaded all recent researches in those dis- 
tricts. It is rightly a member of the Lusitanian fauna, and 
extends its range throughout the Mediterranean ; in many 


parts of which sea it is as common as it is rare on our 
coasts. 


C. ecuinatum, Linnzus. 


Large, suborbicular, more or less strong; ribs only eighteen 
or nineteen, much elevated, square-topped, spinous; interstices 
with coarse irregular and somewhat flexuous elevated wrinkles. 


Plate XX XIII. fig. 2, and (Animal) Plate N. fig. 3. 


Lister, Hist. Conch. pl. 324. f. 161. 

Cardium echinatum, Linn. Syst. Nat. ed. 12, p. 1122.—Prnn. Brit. Zool. ed. 4, 
vol. iy. p. 90 (badly).—Da Cosra, Brit. Conch. p. 176, 
pl. 14, f. 2.—PuntTeney, in Hutchins, Dorset, p. 30.— 
Donoy. Brit. Shells, vol. iii. pl. 107, f. 1.—Monv. Test. 
Brit. p. 78 (not variety).—Linn. Trans. vol. viii. p. 63.— 
Dorset Catal. p. 31, pl. 6, f. 2.—Turr. Conch. Diction. 
p- 29.—Turv. Dithyra Brit. p. 183.—FLEm. Brit. Anim. 
p-421.—Maceint. Moll. Aberd. p. 271.—Brit. Marine — 
Conch. p. 96.—Browy, Illust. Conch. G. B. p. 87, pl. 34, 
f. 6.—CuEMN. Conch. Cab. vol. vi. p. 165, pl. 15, f. 158, 
(badly ).—Magaz, Berlin. Gesel. Naturf. vol. ii. p. 113.— 
Mutter, Zool. Danica, pl. 13, 14.—Woop, General 
Conch. p. 208, pl. 49, f. 1, 2—Lam. Anim. s. Vert. (ed. 
Desh.) vol. vi. p. 396.—Index Testaceol. pl. 5, f. 2.— 
Puiiert, Moll. Sicil. vol. i. p. 49, and vol. ii. p. 37.— 
Hant. Recent Shells, vol. i. p. 131, pl. 5, f. 2. — 

REEVE, Concho]. Iconica, Cardium, pl. 6, f 34. 

3 mucronatum, Pout, Test. Sicil. vol. i. pl. 17, f. 7, 8. 
os spinosum, SOWERBY, British Miscellany, pl. 32,—Linn. Trans. vol. viii. 
p- 63. 


The general form is suborbicular, and very slightly heart- 
shaped, exhibiting a trifling degree of obliquity, and be- 


8 CARDIADA. 


coming of a more elongated outline with age. The valves 
are occasionally very solid, yet quite as frequently, but 
moderately strong, and not particularly heavy: they are 
opaque and tumid, destitute of lustre, and range from 
whitish (usually with squalid zones) to brownish rust 
colour. The surface is radiated with eighteen or nineteen 
strong and elevated ribs, which, emanating from the in- 
curved beaks, squarely dentate the ventral margin at their 
termination. These ribs, which are well raised, and some- 
what square-topped, bristle with crowded spines, which, 
planted nearly in the centre of them, are connected at their 
bases with each other, and assume a different look and 
shape according to the stages of growth and their various 
positions upon the shell. They are never much produced, 
-and are generally indeed decidedly short: in the young, 
they are so compressed laterally as to form a coarsely ser- 
rated carma upon the ribs, which is consequently their 
appearance upon the umbonal region of the adult; they 
next become almost separated pyramidal sharp-pointed 
spines, of which the anterior rows are suddenly bent back- 
wards, and their upper surfaces a little grooved out ; 
finally the sharp ends gradually wear off, and their bases 
become solid, and no longer compressed. These prickles, 
which are generally of a paler hue than the ground colour, 
are coarser, More remote, and more spatulate in front ; 
smaller, sharper, and more clustered behind. The inter- 
stices of the costz are about equal to them in breadth, and 
are coarsely irregularly and somewhat flexuously rough- 
ened by concentrically disposed elevated wrinkles, whose 
peculiarities are most marked at the extremities of the 
shell, where the ribs greatly diminish in elevation, and their 
proportion to the intervening sulci is no longer observed. 


The ventral margin, by obliquely ascending in front, 


CARDIUM. 9 


attenuates the anterior side; it is well arcuated, and rises a 
little behind likewise, so as to round off the incipient basal 
angulation of that extremity. The dorsal edges are almost 
straight, or barely convex; the front declination is the 
more manifest, but both are very trifling. The posterior 
edge, which is not much curved, forms a distinct angle at 
the upper corner; a less decided angulation takes place at 
the opposite end of the dorsal margin, where it is modified 
by the arcuation of the anterior edge; the front extremity 
is narrowed, the hinder is moderately broad. The liga- 
ment is rather large and projecting, but not elongated : the 
umbonal ridge is obsolete, the space beyond it being 
searcely, if at all, flattened. The umbones are prominent, 
and more ordinarily subcentral; in very large examples, 
however, they closely approach the anterior end; the 
beaks are inflected, and lean slightly forwards ; there is no 
lunule in front of them, but usually a somewhat heart- 
shaped area, devoid of cost, of which the lips are generally 
elevated and pouting. The interior is white or pale, and 
neither stained at the hinge margin nor posteriorly with 
any colouring matter; the position of the external sulci is 
occasionally indicated by the internal surface being rather 
of a browner tint. The lateral teeth are large, and, the 
front one especially, tolerably approximate. 

The diameter of the average of examples does not exceed 
two inches; we have taken a specimen at Torquay, how- 
ever, which is three inches long, and more than two inches 
and a half broad. 

The animal has been more than once figured, and was 
well delineated in the Zoologia Danica. It is shaped like 
the shell, and of a yellowish white or pale yellow colour, 
palest when young. The mantle is very muscular, and 
simple at its edges, white in the young shell, pale brown in 


VOL. Il, Cc 


10 CARDIADA. 


some older specimens. The siphons are short, and but 
slightly separated ; the branchial rather the largest, and 
fringed at its orifice by about sixteen simple white cirrhi, 
with minute yellow points at their bases. The anal orifice 
has its inner margin uniformly plain, but there are below it 
about twelve cirrhi, also red-dotted at their bases. The 
sides of the tubes and the neighbouring part of the mantle 
are dotted with scattered white filaments. Mr. Clark ob- 
serves, that the tubes in a half-grown shell, of which the 
transverse measure was an inch and a half, and the ventral 
an inch and a quarter, were three-fourths of an inch in 
length. The foot is cylindrical, finger-shaped, geniculated, 
pale rose at the head, of a deeper red towards the middle 
and extremity. It is at least twice as long as the shell. 
‘“‘ There are a pair of branchiz on each side of the body, of 
the shape of segments of a circle, the upper one being as 
long as the lower, but from its narrowness not half the 
depth. They are pale-brown, conspicuously striated on 
their outer surfaces; less so within. The palpi are of the 
same colour, and are very long, linear, slender, pointed, and 
marked with raised transverse strie on both surfaces.”— 
Crank MSS. 

This generally-distributed species is one of our most com- 
mon bivalves, and inhabits various depths of water, from 
seven to eighty fathoms, all round our coasts. Muddy 
ground, sandy mud, and muddy gravel, are its fayou- 
rite habitats. It is a solitary species or not truly gre- 
garious, and is both brought up by the dredge from near 
the coast, and taken by trawlers far out at sea. The shores 
are sometimes, after stormy weather, strewed with its 
valves. To enumerate its localities would be to name all 
suitable places around our shores, for it is equally plentiful 
in the northern and southern districts. 


CARDIUM. 11 


It ranges throughout the European seas, and is known 
as a fossil in pleistocene deposits. 


C. rusticum, Linneus. 


Large, solid, with at least twenty much elevated tubercu- 
lated and wrinkled ribs: tubercles more or less squamular on 
the anterior ribs, and more or less prickly on the posterior ones : 
interstices broad, and very coarsely wrinkled. 


Plate XXXI. fig. 3, 4. 


‘Lister, Hist. Conch. pl. 329, f. 166. 
Cardium rusticum, Linn. (not Lam. nor British writers) Syst. Nat. ed. 10, p. 
681, ed. 12, p. 1124.—Pou1, Test. Sicil. pl. 16, f 5.— 
Woop, General Conch. p. 225, pl. 55, f. 2, 3. 
»  tuberculatum, Linn. Syst. Nat. ed. 10, p. 679? ed. 12, p. 1122?; Mus. 
Ulrice, p. 488.—PuLreney in Hutchins, Dorset, p. 30, 
—Donov. Brit. Shells, vol. iii. pl. 107, f. 2—Monr. 
Test. Brit. p. 568.—Linn. Trans. vol. viii. p. 64.—Turvr. 
Conch. Diction. p. 28, f. 12.—Turr. Dithyra Brit. p. 
181.— Fiem. Brit. Anim. p. 421.— Brit. Marine 
Conch. p. 95.—Brown. Illust. Conch. G. B. p. 87, pl 
34, f. 9. —CuEmn. Conch. Cab. vol. vi. pl. 17, f. 173. 
—Du.w. Recent Shells, vol. i. p. 117.—Lam. Anim. 
s. Vert. (ed. Desh.) vol. vi. p. 397.—Hanu. Recent 
Shells, p. 181.—Payraup. Cat. Moll. Corse, p. 55.— 
Puriprt, Moll. Sicil. vol. i. p. 50, and vol. ii. p. 37. 
echinatum, var. MonvaG. Test. Brit. p. 79, and Suppl. p. 33. 
of tuberculare, SOwERBY, Genera of Shells, Cardium, f. 3. 
Encycloped. Méthodique, Vers, pl. 298, f. 3, and pl. 300, f. 1. 


?? 


For thus introducing, under the name of rusticum (ap- 
plied almost universally throughout England and France to 
an aberrant variety of the Common Cockle), a Cardium so 
generally known by the appellation of tuberculatum, some 
few words of explanation will be demanded. The original 
specimen of the Cardium rusticum, named by Linnzus 
himself, has been examined, and is precisely identical with 
the Mediterranean form of the species we are about to de- 
scribe. The C. tuberculatum of Linneus may or may not 
be ours, so indefinite is its description, and so erroneous its 


¥2 CARDIAD A. 


synonymy : we have preferred, then (since one or the other 
name must be expunged), the preservation of that which 
we have ascertained to be correct.* 

This large species is of a somewhat rounded heart-shape, 
and is usually oblique, but varies much in outline from the 
greater or lesser flattening of the hinder dorsal area, which 
being rounded in the young, the contour is then rather 
square, but becomes occasionally subtriangular in the aged, 
from the hinder compression so usual at that stage of 
growth. The valves are very tumid, opaque, solid, and 
often ponderous; the convexity is evenly diffused, being 
most manifest subcentrally, and then gradually diminishing 
towards the sides and lower margin. The external surface, 
which is somewhat glossy, and tinged with rufous or reddish 
brown, occasionally adorned with deeper zones of the same 
hue, is rayed with about twenty-two strong ribs, which 
are separated, except in front, by interstices of at least 
equal breadth to them. The ribs are broad, well raised, 
somewhat square-topped, and armed with rather close-set, 
unconnected small knobs or tubercles, which, in full-grown 
perfect individuals, are present on all of them, and occupy 
the middle of their surface only, becoming more pointed 
on the posterior ones, and more obtuse large and broad on 
the anterior ones. The interstitial spaces, which are pro- 
portionately narrower in front, are concentrically traversed 
by most crowded and irregularly-flexuous narrow ridges 
or elevated sulci, which likewise ascend the sides of the 
ribs, and in the younger examples actually surmount them. 
The tubercles (which, in a variety now before us, are large 
and spinous, but not, as in echinatum, laterally. com- 
pressed and radiatingly linked to each other) are usually 


* Fora more detailed account of the Cardiwm tuberculatum of Linneeus, see 
the “ Ipsa Linnzei Conchylia” of Mr. Hanley, now in preparation for the press. 


CARDIUM. 3 


more or less tinged with brown, and seated on a shallow 
groove, which appears to connect them ; but in aged speci- 
mens this is wont to become obsolete, and the knobs to be 
converted into concentrically linear strong scale-like pro- 
tuberances towards the ventral margin. This latter, in the 
adult, is by no means arcuated in the middle, but curving 
out and obliquely ascending in front, (far more than equal 
to the downward inclination of the upper edge,) attenu- 
ates below the rounded extremity of the anterior side. 
It rises too posteriorly, but only sufficient to round off a 
little the inferior angle of that side. The hinder margin, 
although arcuated in the young, loses much of its con- 
vexity, or becomes straightish and occasionally subretuse 
in the mature shell, and is then moreover decidedly oblique. 
The declination of the dorsal edges is extremely trifling ; 
the front one, however, slopes the most; their want of 
convexity causes a more or less indistinct angulation at 
the upper posterior corner, and prevents, likewise, the sym- 
metrical rounding of the front one. The umbones are pro- 
minent, and nearly central in the young, but in the adult 
are distant from the anterior extremity only about two- 
fifths of the entire length of the valves. The beaks are 
greatly inflected, and slightly.inclme forward-; no defined 
lunule precedes them, but there exists in the mature shell a 
flattened area with subreflected lips, which is devoid of 
coste, and often stained with a darker tint. The ligament 
is large and projecting: the umbonal slope is but little an- 
gulated. Internally the colour is white, with occasionally a 
rufous tint on the profundity of the valves, but no stain of 
brown either upon the hinge-margin, or at the posterior 
termination. The ribs on the inside extend only half way 
to the beaks. The lateral teeth are moderately remote and 


subequidistant ; the front one is large and strong. 


14 CARDIADA. 


We cannot feel surprised that our British conchologists 
have not hitherto recognized the identity of our C. tubercu- 
latum with the rusticum of the Mediterranean, as the 
ordinary state in which the latter usually reaches us, desti- 
tute of knobs, and beautifully zoned with a rich brown ona 
whitish ground (our own variety is generally of an uniform 
pale rufous), would not, until actual comparison, induce the 
supposition of their identity. The shape of the Mediter- 
ranean examples is frequently much more abbreviated than 
ours, so that the breadth almost equals the length, and the 
interstitial rugee are perhaps less irregularly flexuous; but 
in no essential characters, do they differ from those which 
are indigenous to our coast. 

Individuals rarely exceed two inches and three quarters 
in length, and a trifle less in breadth. The young bear but 
little resemblance to the fry of echinatum or aculeatum, 
being solid (even when less in diameter than half an inch), 
and armed with minute tubercles, instead of compressed 
lancet-shaped spines. According to Turton, they are of 
a chocolate-brown, with white blotches or rays; the first 
stage of growth, however, in our own shells, is pure white. 
The animal is figured and described by Poli; the mantle 
is thickened and denticulated posteriorly ; tubes cirrhated, 
and with the mantle of a yellow or red colour; the foot 
long and crimson. 

As a British species it is essentially local, and by no 
means frequent in collections. These shells, however, 
abound at certain seasons ‘‘ On the Paignton sands in Tor- 
bay, where at low spring-tides they may be observed, with 
the fringed tubes appearing just above the surface. The 
neighbouring cottagers gather them in baskets and pan- 
niers, and after cleansing them a few hours in cold spring- 


water, fry the fish in a batter made of crumbs of bread, 


CARDIUM. 15 


producing a wholesome and savoury dish. The inhabitants 
call them red noses” (Turton). The loose valves are scat- 
tered along the Cornish shores, and in some places in 
abundance, as in Lantivet Bay, east of Fowey (Couch). 

It is essentially a southern species, and ranges to the 
Canaries. 


C. repute, Linnzus. 


Neither triangular, nor porcelain white ; with radiating ribs, 
which are neither armed with spines nor tubercles. 


Plate XXXII. Fig. 1 to 4, and (animal) Plate N. Fig. 5. 


Lister, Hist. Conch. pl. 334, f. 171. 
Cardium edule, Linn. Syst. Nat. ed. 12, p. 1124.—PEnwn. Brit. Zool. vol. iv. p. 
91, pl. 50, f. 41.—Putreney, Hutchins, Hist. Dorset, p. 30.— 
Donoy. Brit. Shells, vol. iv. p. 124, f. 1.—Monr. Test. Brit. 
p- 76.—Linn. Trans. vol. viii. p. 65.—Dorset Catalog. p. 32, 
pl. 11, f. 1.—Turr. Conch. Diction. p. 30.—Turr. Dithyra 
Brit. p. 188.—F1iem. Brit. Anim. p. 422.—Coucn, Cornish 
Fauna, part ii. p. 28.—Maceiziiv. Moll. Aberd. p. 272.— 
Brit. Marine Conch. p. 97.—Brown, Illust. Conch. G. B. p. 
87, pl. 35, f. 1 to 6.—CaEmn. Conch. ee vol. vi. p. 198, 
pl. 19, f. 194.—Woop, General Conch. p. 226, pl. 55, f. 4.— 
Ditiw. Recent Shells, vol. i. p. 127. aie Ae Anim. s. Vert. 
(ed. Desh.) vol. vi. p. 406.—Index Testaceolog. pl. 5, f. 26.— 
Rees’ Cyclopedia, pl. 5.—Cuv. Régne Animal (ed. Croch.), 
pl. 99, f. 4.—Hanu. Recent Shells, vol. i. p. 134, pl. 5, f. 26. 
—ReExrve, Conch. Iconica, Cardium, pl. 4, f. 22 
», vulgare, Da Costa, Brit. Conch. p. 180, pl. 11, f. 1. 
is crenulatum, LAM. Anim. s. Vert. (ed. Desh.) vol. vi. p. 407.—DeE Es. 
Rec. Coquilles, pl. 11, f. 5.—RzExvx, Conch. Iconica, 
Cardium, pl. 20, f. 112. 
»  pectinatum, LAm. Anim. s. Vert. (ed. Desh.) vol. vi. p. 405.—HANL. 
Recent Shells, vol. i. p. 134. 
6 arcuatum. REEVE (not Mont.), Conch. Icon, Cardium, pl. 22, f. 33. 
~ zonatum, BRowNn, Illust. Conch. G. B. p. 88, pl. 35, f. 8. 
obliquum, Woopwarb, Geol. Norf. pl. ii. f. 19 (fossil). 
meron. Méthod. Vers, pl. 300, f. 5. 


So different is the outline of the aged Cockle from that of 
the nearly mature one, that, in despite of the extreme com- 


16 CARDIADZ. 


monness of the shells, which offers every facility for ascer- 
taining the exact extent of the species, the latter state has 
been separated by Lamarck, and some of his followers, as a 
distinct species, under the name of C. crenulatum. 

The shape of the adult Cockle is subovate and subcordate, 
ranging occasionally to subtrigonal and suborbicular; in 
the latter case, the valves, which are always ventricose 
and typically inequilateral, become eminently swollen, and 
nearly equilateral. The texture is opaque, solid (occa- 
sionally ponderous), and of a squalid white, frequently with 
a ferruginous cast, but never marbled nor variegated exter- 
nally. 

The outer surface is dull, and occasionally covered in 
part with an ashy-olive fugacious epidermis, usually con- 
fined, however, to the posterior end, and the vicinity of the 
lower margin. About twenty to twenty-six radiating ribs 
are visible, which are tolerably evenly diffused over the 
entire surface ; the two or three which cover the ordinary 
site of an umbonal ridge are, however, rather the largest, 
and the succeeding ones decidedly the narrowest of the 
series. These ribs are but little elevated (the terminal ones 
are, indeed, greatly depressed), and only separated from 
each other, in the more characteristic examples, by narrow 
grooves on the central disk, and concave (not square cut), 
rather broader ones at the sides. Crowded and slightly- 
curved linear elevations concentrically traverse the summit 
of the ribs, but become obsolete upon the posterior ones. 
The ventral edge, which is always more or less curved, and 
occasionally much arcuated, usually displays less convexity 
behind than in front, where it ascends with a bold sweep, 
forming a well-rounded and not very broad anterior ex- 
tremity. The dorsal edges are straightish, or even subre- 


tuse, and decline but in a trifling degree ; the posterior edge 


CARDIUM. ily; 


after forming a slight angle with the dorsal margin, slopes 
somewhat obliquely, and makes with the ventral a rounded- 
off inferior angle to the hinder side, which is occasionally 
much produced, and tapering at its extremity, occasionally 
broad, subbiangulated, and scarcely longer than the front 
one. The umbones are greatly prominent, and the beaks 
very acute, and much inflected. 

The ligament is very large, and highly projecting. The 
interior is white, with a dark-chestnut stain at the posterior 
extremity, and often a still deeper one on the hinder hinge- 
margin. The lateral teeth are strong, much elevated, not 
very remote, and nearly equidistant. 

If we take an earlier stage of this bivalve, for instance, an 
example not exceeding three-fourths of an inch in length, 
we shall perceive many and important differences, but such 
as may be traced up in regular gradation to the mature 
shell. The shape is then suborbicular, the sides equal or 
nearly so, there being no inferior hinder angle ; an upper pos- 
terior subangulation is, however, distinctly visible, and the 
hinder outline is more or less convex, and scarcely oblique. 
The ribs are rather more elevated, and all of them adorned 
with the linear scales (which, however, are very easily worn 
away), and flexuous livid zones occasionally make their 
appearance on the umbonal region. 

Although apparently differing from edule quite as essen- 
tially as many of the more recently established species of 
Cardium do from each other ; yet, as we are able to appre- 
ciate in the rusticwm of British writers the modifications of 
form, sculpture, and colouring, produced by a greater or 
lesser admixture of fresh water with the saline element, we 
venture not to describe it as specifically distinct, but hold it 
rather as a remarkably aberrant variety of the Common 
Cockle. 


VOL, II. D 


18 CARDIAD. 


urdium rusticum, CHEMN. (not Linn. nor Hanl.) Conch. Cab. vol. vi. pl. 19, 
f. 197.—Monrt. Test. Brit. p. 569.—Donov. Brit. Shells, 
vol. iv. pl. 124, f. 2.—Pout, Test. Sicil. pl. 17, f. 12, 13. 
—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 405.—DeEs- 
Hayes, Elem. Conch. pl. 25, f. 1 (good).—Puiier!, Moll. 
Sicil. vol. i. p. 52, pl. 4, f. 12, 13, 14, and vol. ii. p. 38. 
» glaucum, BruGiEre£, Encycl. Méthod. Vers, vol. i. p. 221.—PorRET, 
Voyage Barbarie, vol. ii. p. 13.—Woop, General Conch. 
p. 218.—Dittw. Recent Shells, vol. i. p. 180.—HaANL. 
Recent Shells, suppl. pl. 17, f. 36. 
a Lamarckii, Rexve, Conch. Iconica, Cardium, pl. 18, f. 93. 
on Belticum, REEv®, Conch. Iconica, Cardium, pl. 20, f. 113. 
a edule, Brown, Illust. Conch. G. B. pl. 35, f. 7.—Puuizier1, Moll. 
Sicil. vol. i. p. 52, and vol. ii. p. 39. 


The contour is still more variable than in the typical 
form, being not only irregular in the degree of elongation of 
the posterior side, which is sometimes much produced, but 
also exhibiting at times an obliquity which is by no means 
constant. The valves at all stages are thinner and more 
swollen than those of the type, and have their ribs much 
more elevated, convex, and separated from each other by 
broader interstices. The linear concentrically-disposed 
scales have a great tendency to become obsolete, and are 
usually only visible, if at all, near the front extremity and 
towards the ventral margin, where, if present, they are 
generally crowdedly arranged. ‘The hinder side, and very 
frequently the umbonal region, is stained with bluish smoke- 
colour or livid brown, which latter tint more or less prevails 
over the interior surface likewise. Ordinarily, but not in- 
variably, the shape 1s more elongated than in the marine 
shells, and the front, and not the hinder dorsal margin, is 
the more elevated, so that the anterior side becomes pro- 
portionately higher. The umbones are broad, and extraor- 
dinarily tumid ; the ligament is decidedly smaller than in 


CARDIUM. 19 


the ordinary variety. The posterior ventral margin seems 
always rounded off. 

The collective amount of these differences is very great ; 
but all are rarely developed in the same specimen, since this 
variety approaches to or recedes from the typical form in 
proportion to the influx of salt-water into the brackish 
stream in which it is engendered. Some very beautiful 
ones, whose glossy surface is of a pale sulphur colour, are 
obtained in the vicinity of Hastings (S. H.). The salt-water 
marshes of Hampshire (Dr. Goodall); Arran, in Ireland 
(Ball); the Murray Frith (M‘Andrew), &c., may also be 
indicated as localities. 

The edible Cockle seems met with in most parts of the 
United Kingdoms, and is almost everywhere regarded as a 
savoury food by the humbler classes of society. The or- 
dinary run of examples does not exceed an inch and four- 
fifths in length, and an inch and a half in breadth; but in- 
dividuals of far more ample proportions are procured on the 
north coast of Devon (Jeffreys); the Scilly Isles (M‘An- 
drew); and in the Hebrides (Barlee). 

The animal of the common Cockle is shaped like its 
shell, thick, subglobose, and white. The mantle is of a yel- 
lowish hue, and differs from that of many of its allies in 
having a considerable portion of its edges more or less fim- 
briated, and also being furnished with a short white fila- 
ment opposite each rib of the shell. The siphonal tubes 
are short and slightly separated, the branchial largest, and 
has its orifice fringed with about ten long white cirrhi, and 
two or three intermediate small ones between each pair. A 
reddish-brown hue encircles it, as also the anal siphon, 
which, however, has no cirrhi on its border: the usual 


tubular anal valve is conspicuous. The sides of the siphons 


20 CARDIADA. 


are variable in colour, white, yellow, or brownish-red, 
sometimes speckled with black spots or markings, and they 
are clothed with scattered filaments, as well as the mantle 
near their bases. The foot is long and cylindrical, but not 
so large in proportion to the shell as in most of the Cardia, 
geniculated, and of a white or yellow colour, passing to a 
deeper hue, often brown or light orange towards its some- 
what lanceolate extremity. The branchie are pale-brown 
and suboval, the upper lamine being smallest ; and the 
palps are triangular, rather long, acute, and of a reddish- 
brown hue. 

The edible Cockle is a gregarious animal, inhabiting sands 
at low-water, and met with on most parts of our coast, 
especially where there are sufficient tracts of sand, and in 
the neighbourhood of estuaries; though the largest speci- 
mens are chiefly found away from the influence of fresh 
water, as in the Scilly Isles (M‘Andrew), the north coast 
of Devon (Jeffreys), the Hebrides, and Zetland. The 
variety most common in our markets rarely exceeds an 
inch and four-fifths in length by an inch and a half in 
breadth, and comes, in most cases, from estuary sands, 
those of the Mersey being especially prolific. Everywhere 
this excellent mollusk is sought after for food, and it is one 
of the most savoury of its tribe ; indeed, preferred by many 
persons to the oyster. It is equally good raw and cooked, 
dressed either by roasting or boiling, and gives a delicious 
flavour to fish sauce. Cockles are also often pickled, as 
the readers of Ingoldsby’s treasured story of the Bald- 
headed Jackdaw will not readily forget. In times of 
scarcity they have afforded valuable supplies of food for the 
poor, and in the Zetland Isles bushels of their shells may 
be seen near cottages. Lieut. Thomas informs us that in 


Sanda, among the Orkney Isles, during the late failure of 


CARDIUM. Di 


the potato crop, many of the poorer people subsisted almost 
entirely on Cockles. 

Cockles found in coarse-bedded sands in the neighbour- 
hood of tide-ways are often much thicker in the shell than 
those of confined and sheltered localities. A note, commu- 
nicated by Mr. R. Ball, on the Arran (Ireland) variety, 
already mentioned, is illustrative of this. ‘In 1834,” 
writes that accomplished naturalist, ‘“‘when visiting the 
Great South Arran, in company with Mr. Thompson, we 
found an interesting variety of Cardiwm edule in a brack- 
ish lake at the northern end of the island. The shells were 
remarkably thin and brittle; the animals were not buried 
in sand, but appeared to inhabit the Conferva crassa, in 
which the majority of specimens were found creeping about. 
I supposed that the thinness of the shell was occasioned 
by the influence of the fresh water, but finding that the 
Cockles of the brine-pits are equally thin, this notion must 
be given up: the probability is, that the cause depends on 
the quiescent habitat. The greater number of specimens 
were very small, about a quarter of an inch in diameter : 
a few larger examples were found on the shore of the lake ; 
they were associated with a very produced variety of Lit- 
torina jugosa.” 

Cardium edule has a wide range, extending southward 
to the Canary Isles, and a Cockle which cannot be distin- 
guished from it occurs in the Caspian Sea. In the Arctic 
seas it is replaced and represented by the Cardiwm Island- 


icum. As a fossil it is known in the Red Crag. 


22 CARDIADA. 


C. noposum, Turton. 


Small, never porcelain white, nor marked with coloured bands; 
ribs about twenty-seven in number, all armed with scaly tu- 
bercles. 

Plate XXXII. fig. 7. 


Cardium nodosum, TurTON (not Montagu, Maton and Rackett, nor Wood) 
Dithyra Brit. p. 186, pl. 13, f. 8.—HAnu. Recent Shells, 
136, suppl. pl. 17, £. 44 (copied from last)—Loven, Moll. 
Skandin. p. 36.—REEVE, Conch. Iconica, Cardium, pl. 22, 
f. 128. 
scabrum, Purtrppi, Moll. Sicil. vol. ii. pl. 14, ££ 16.— Hant. Recent 
Shells, Suppl. pl. 17, f. 43. 


”° 


The shape is suborbicular, subrectangular at the beaks, 
and rather wide below. The valves are moderately ventri- 
cose, the convexity being rather evenly diffused, and gradu- 
ally diminishing from the umbones; they are more or less 
strong, opaque, and usually of an uniform rather squalid 
white or pale cream colour, and very rarely stained with 
orange or pink upon the umbonal region. The surface is 
entirely radiated over with about twenty-eight narrow 
moderately-elevated ribs, separated by still narrower deep- 
ly-cut interstices: these ribs are most crowdedly set with 
squamular tubercles, which, in different individuals, vary 
in shape, from suborbicular to linear sublunate, and have 
a tendency to become depressed in front, and spinous be- 
hind upon the posterior area; which latter is distinctly flat- 
tened, but its commencement is not indicated by any 
peculiarly sharp angulation. ‘The ventral margin is mode- 
rately arcuated, and ascends in front, where the convexity 
is more decided. The degree of convexity and of declina- 
tion in the dorsal edges is but trifling; the hinder one is 
decidedly the more sloping. The sides are nearly equal, 
the front being, in general, rather the shorter, and being 


CARDIUM. 23 


broad and rounded both above and below at its extremity. 
The hinder termination is likewise broad, and very indis- 
tinctly sub-biangulated, the lower angle being a right or 
an obtuse one, and the upper being usually rounded off. 
The lunular depression, when present, is very narrow: the 
ligament is neither remarkable for size nor projection. The 
umbones are not particularly prominent, and the beaks are 
tolerably acute, and scarcely inclined forward. The colour- 
ing of the inner surface is similar to that of the external ; 
in a single immature specimen, however, from Guernsey, 
which is of a pale pink without, the internal disk is of 
a deep rose-colour. The lateral teeth are nearly equidis- 
tant from the primary ones. A large specimen will occa- 
sionally attain to almost half an inch in length, and a trifle 
less in breadth ; but the majority of examples are of lesser 
proportions. 

It is difficult to account for so generally diffused a spe- 
cies having escaped observation until the publication of the 
“ Dithyra Britannica” of Dr. Turton; since but little rea- 
sonable doubt can be entertained that this is not the C. 
nodosum of Montagu, which is described as being three 
quarters of an inch in diameter, and of a flattened shape. 
The language, indeed, of that author accords far better with 
the young of tuberculatum, of which species a tablet of im- 
mature individuals, supposed to have once formed part of the 
Colonel’s collection, exists, thus named in our national 
Museum. 

«¢ Animal suborbicular, mantle white, open, clothed with 
white pointed filaments, corresponding to the ribs of the 
shell. The tubes are very short, pale yellow, each with 
ten or twelve flaky white cirrhi at their extremities, and 
red points at their bases, besides longer wavy white fila- 
ments above and below, and on them. The anal orifice has 


24 CARDIADA. 


the usual tubular valve. The foot is white, moderately 
long, and finger-shaped, with a slight bend or elbow. 
There are a pair of subsemicircular branchiz on each side, 
strongly pectinated on the upper, and less so on the under, 
surfaces. The upper branchie are very small, not half the 
length and depth of the under ones. Two very small tri- 
angular palpi on each side, pectinated in a similar manner 
with the branchie.”—Crarxk MSS. 

This little cockle is chiefly an inhabitant of the lami- 
narian zone, though it ranges far into the coralline oc- 
casionally. It frequents weedy and gravelly bottoms, and 
can scarcely be regarded as a common species. On the 
south coast it occurs at Weymouth (S. H.); in fifteen 
fathoms, off Portland (M‘Andrew and E. F.) ; Exmouth 
(Clark) ; Torbay (S. H.); Falmouth and Fowey (Alder). 
Mr. Bean finds it at Scarborough, and Mr. Alder in North- 
umberland. In Scotland it is frequent in the Hebrides 
(Jeffreys and Barlee); Stornoway, four fathoms, sand, 
and Zetland as deep as eighty fathoms (M‘Andrew). It 
is one of the species found by Captain Beechey in, the 
ravine more than one hundred fathoms deep, between Ire- 
Jand- and the Mull of Galloway. It is common among 
weed, in from three to ten fathoms, in Clew Bay, and 
similar localities on the west coast of Ireland; and Mr. 
Thompson notes it as inhabiting both sides, ‘“ generally 
in deeper water than Cardium pygmaum.” Bantry Bay 
(Humphreys). ; 

It ranges from the shores of Norway to the Mediter- 
ranean. 


CARDIUM. 25 


C. rasctratum, Montagu. 


Small, thin, oblique; ribs scarcely raised, only divided from 


each other by linear spaces, the central ones devoid of sculpture, 


the hinder ones prickly : umbonal slope not angulated. 


Plate XXXII. fig. 5, and (Animal) Plate N. fig. 4. 


Cardium fasciatum, Mon. (not Gmel.) Test. Brit. Suppl. p. 30, pl. 27, f. 6.— 


Tur. Conch. Diction. p. 32.—F Lem. Brit. Anim. p. 422. 
—Brit. Marine Conch. p. 98.—Browy, Illust. Conch. G. 
B., p. 88, pl. 35, f£. 11.—Woop, General Conch. p. 215.— 
Dittw. Recent Shells, vol. i. p. 130-—RuzxEve, Conch. 
Iconica, Cardium, pl. 21, f. 118.—Lovén, Moll. Skandi- 
nayiz, p. 35 (from specimens). 
elongatum (not of Bruguiere, 1792), Monv. Test. Brit. p. 82! (fide Tur- 
ton, &c.)— Linn. Trans. vol. viii. p. 67 (from Mont.)— 
Turv. Conch. Diction. p. 3] (do).—Woop, General Conch. 
p- 214 (do.).—Dintw. Recent Shells, vol. i. p. 131 (do.). 
—Torrt. Dithyra Brit. p. 185, pl. 13, f. 9.—F1Lem. Brit. 
Anim. p. 422. 
ovale, SowERBY, in Conchol. Illust. Cardium, No, 24.—Hanu. Recent 
Shells, voi. i. p. 186, suppl. pl. 17, f. 45.—Rexzve, Conch. Ico- 
nica, Cardium, pl. 21, f. 119. 
obovale, Brit. Marine Conch. p. 96 (error for ovale). 
parvum, Puitipri, Moll. Sicil. vol. ui, p. 39 ? 
rubrum (young), REEVE, Conch. Iconica, Cardium, pl. 22, f. 124. 


The shell which we have figured and described is unde- 


niably the C. elongatum of Turton’s quarto, of which the 


young state alone agrees with the C. fasciatum of Montagu. 


The language of the author of the ‘ Testacea Britannica ” 


(who terms it compressed, and allows it but twenty-one ribs) 


would not, in our opinion, warrant the identification of his 


elongatum with the bivalve now before us; but as the 


original inadequate description is unaccompanied by any 


figure which might enlighten us as to what was actually 


intended, and the type has been vainly sought for in the 


National Museum (whither the chief part of his collection 


VOL. 


Il. E 


26 CARDIADZ. 


was sent after his decease), we have yielded, though not 
silently, to the dictum of Turton, who probably founded 
his recognition on some original types which are no longer 
accessible. The name ovale was only introduced to 
remedy the pre-occupation of the epithet elongatum by 
a magnificent exotic species; fasciatum, notwithstanding 
its having been already bestowed on a Cardium, is allow- 
able, since Gmelin has merely used it to designate a wretched 
figure of Knorr’s, from which drawing solely he has derived 
his bald and undefining diagnosis. 

The form is more or less oblique and oboval, with, 
at times, a tendency to be heart-shaped; at times, to be 
subquadrate. The texture is thin and fragile, but not at 
all diaphanous, and the valves are more or less ventricose. 
The colouring is white, with often a slight livid tinge, and 
almost invariably with short concentric bands of undulated 
brown streaks, which do not traverse the entire shell but 
are confined, excepting near the beaks, to the posterior 
side. These bands, moreover, ere less evident and more 
livid in the adult; but even when almost obsolete exter- 
nally, their presence may be traced in the interior. The 
surface is divided by about twenty-six radiating ribs, 
which are by no means prominent, the central being 
scarcely raised in the slightest, and merely a little convex, 
and those at the sides, with the exception of a few rounded 
ones upon the umbonal ridge (which is very oblique and 
rendered tolerably distinct by the surface being flattened 
behind it), are at most convex. The central ribs (except 
in the fry) are smooth and unarmed; but the lateral are 
sculptured by oblique tubercles, of which those upon the 
front ones are rather depressed, linear, crowded, transversely 
occupying the entire surface, and sloping down anterior- 


ward ; those upon the hinder ones are elevated horizontally 


CARDIUM. aT 


subsquamular, more or less compressed, close-set, sloping 
down posteriorwards, and not extending transversely over 
the entire ribs. The interstitial lines, separating the ribs 
from each other, are extremely delicate near the middle of 
the valves, and even at their extremities are still very 
narrow; these lateral ones are traversed by slightly- 
elevated crowded concentric wrinkles, which are some- 
times slightly indicated at the base of even the central 
strie. The ventral margin is much arcuated, yreatly 
ascending at its posterior termination (and thus narrowing 
the shell at that extremity), and not straightened in front. 
The anterior dorsal edge declines but moderately, and is a 
little convex ; the posterior dorsal edge is very short, very 
slightly convex, and slopes downwards in a very trifling 
degree. The posterior outline is barely convex, and the 
extremity, though a little rhomboidal, is rounded both 
above and below ; the front extremity is likewise rounded, 
but is a little angular above. The beaks are situated much 
nearer to the posterior end, to which they usually lean, and 
are acute and moderately projecting. There is no trace of 
a lunule, and the ligament is very small, narrow, and only 
slightly prominent. The interior partakes of the external 
colouring; the lateral teeth are of moderate size, and sub- 
equidistant; the front one is rather the more approximate. 

It is intermediate between C. nodosum and C. exiguum, 
but is a far thinner shell than either of them. Its outline 
is much more oblique than the former, and its central ribs 
are devoid of the graceful sculpture which adorns the 
entire surface of that species. It more closely approaches 
the latter, but its convexity is more evenly diffused, its 
umbonal ridge not sharply angulated, and its ribs more nu- 
merous and less elevated. These, in eaiguum, are se- 


parated from each other by far wider grooves, which are all 


28 CARDIADA. 


traversed by concentric wrinkles; that shell, moreover, is 
much more angular in outline, has a slight lunule, with its 
front costal tubercles roundish and not linear. 

The length of a full-sized example is not quite half an 
inch ; its breadth is three-eighths of an inch. 

The animal is shaped like the shell, and entirely white, 
with semi-opaque or flaky specks. The mantle is plain at 
the margins. The tubes are not extended beyond the 
eighth or fourth of an inch; they are equal and united ; 
the anterior one has a distinct border of about ten cirrhi, 
which is not so evident around the anal siphon. Their 
sides, and the mantle near their bases, are furnished with 
longer filaments. The foot is long, securiform, and hyaline. 
“The branchiz,” according to Mr. Clark, ‘“ are subsemi- 
circular, pale brown, the upper not half the size of the 
lower, strongly striated on the outside, smoother within ; 
the pair of palps are very short, triangular, and pointed ; 
striated on the outer, and much less so on the inner sur- 
face. The liver is green and placed very anteriorly ; the 
ovarium is white.” 

This is one of our rarer Cardia, and is more frequently 
procured dead and worn than, in its perfect condition, 
armed with the caducous sculpture of its posterior area. 
We suspect that the Cardiwm fasciatum of Montagu 
(Test. Brit. Suppl. p. 30, pl. 27, fig. 6), was established 
from a young worn example of this species; at least, the 
figure and description agree better with that stage of the 
shell in which the flexuous chestnut bands occupy nearly 
the entire surface, than with any other cockle known to 
inhabit the British seas. On our southern coasts it 
occurs in from fifteen to twenty-seven fathoms off Port- 
land, and in twenty to twenty-seven fathoms off Penzance 


(M‘Andrew and E. F.); Torbay (S. H.) ; Whitesand 


CARDIUM. 29 


Bay (Jeffreys); and Exmouth offing, seven miles from 
land (Clark). On the east coast it is taken at Scarbo- 
rough (Bean), and is locally abundant on the Northumber- 
land and Durham coasts (Alder). It is rare in the Irish 
Sea. Dredged very sparingly in Belfast Bay and Strang- 
ford Lough in from six to ten fathoms, by Mr. Hyndman 
and Mr. Thompson. Portmarnock (Warren) ; Birterbuy 
Bay (Barlee); Bantry Bay (Humphreys). On the west 
coast of Scotland it is frequent, occurring chiefly in from 
fifteen to thirty fathoms, as at Oban, Skye, and Loch 
Fyne (M‘Andrew and E. F.). Mr. Jeffreys and Mr. 
Barlee have taken it in many places among the Hebrides. 
Off the coast of Zetland it ranges from shallow water to 
considerable depths, occurring near shore in from five to ten 
fathoms, and on the Ling banks, thirty or forty miles from 
land, in fifty fathoms (M‘Andrew and E. F.). 

It ranges to the Norwegian Seas (Lovén). As a fossil 
it dates back as far as the epoch of the Coralline Crag 


(Searles Wood). 


C. pyamaum, Donovan. 


Small, subrhomboidal, very inequilateral, compressed in front, 
ventricose, and sharply angulated at the umbonal ridge: front 
extremity narrow and angulated ; hinder extremity very broad, 
and biangulated. 


Plate XXXII. fig. 8, and (Animal) plate N. fig. 2. 


List. Historia Conch. pl. 317, f. 154. 
Cardium pygmeum, Donov. Brit. Shells, vol. i. pl. 32, f. 3. 

- exiguum, Monv. Test. Brit. p. 82.—Linn. Trans. vol. viil. p. 61.—Dor- 
set Catalogue, p. 31, pl. 2, £ 11.—Turr. Conch. Diction. p. 
31.—Turv. Dithyra Brit. p. 186.—FiLem, Brit. Anim. p. 
422.—Maceitnivray, Moll. Aberd. p. 273.—Brit. Marine 
Conch. p. 97.—Brown, Illust. Conch. G. B. p. 88.—Woop, 
General Conch. p. 212.—Ditiw. Recent Shells, vol.i. p. 114. 
—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 408.—PHILIPPI, 


30 CARDIADZ. 


Moll. Sicil. vol. i. p. 51, and vol. ii. p. 38.—HANL. Recent 
Shells, p. 135.—Rexrvex, Conch. Iconica, Cardium, pl. 21, f. 
121. 


Although Gmelin’s name, exiguum, is prior to that of 
Donovan, yet as his species was merely constructed from 
the figure in Lister, and inadequately defined, it has no 
just claim to precedence. 

There isa something so marked in the general outline and 
moulding of this peculiarly angulated cockle, that a hasty 
glance at even a worn and discoloured valve will enable us 
to discriminate it from its British congeners. 

The contour is rhomboidal, with the hinder dorsal edge 
so extremely short, that, excluding the umbones, the shape 
may be termed triangular. The hinder dorsal area, which 
is broad and abruptly flattened, is defined in front by the 
extremely oblique and sharply-angulated umbonal ridge, at 
which point is the greatest tumidity of the valves, which, 
gradually decreasing in convexity, become compressed at 
the anterior extremity. The external surface is destitute of 
lustre, and of a white, or dirty-whitish hue, marked occa- 
sionally with interrupted irregular bands of brownish rufous 
spots, which are more perceptible towards and upon the 
umbonal ridge. Although the shell is small, its texture 
nevertheless is solid and opaque ; the entire area is occupied 
by from twenty to twenty-two radiating ribs, which are 
rather broad, not much elevated, and divided from each 
other by distinct sulci, which become much wider at the 
hinder extremity. These interstitial sulci are concentrically 
punctated with impressed dots or lines, and the ribs them- 
selves are armed with close-set coarse roundish nodules, 
which in the young pervade the entire surface, but in the 
more aged individuals are confined to the front of the shell 
and the portion bordering upon the ventral margin, the re- 


CARDIUM. 31 


mainder gradually becoming obsolete, or wearing off as age 
advances. The ventral edge, which ascends most remark- 
ably in front, displays but little convexity behind, scarcely 
rising from the central arch on that side of the shell. The 
front dorsal edge is straight or subretuse, and slopes most 
rapidly, forming a distant subcentral angle with the up- 
turned ventral. The hinder dorsal edge, which is also 
straight, becoming a little rounded at the extremity, in- 
stead of declining, rises a little. The posterior margin is 
almost straight, and when young is comparatively perpen- 
dicular, becoming more oblique with age. The front ex- 
tremity is very narrow, the hinder is very broad and bian- 
gulated. The umbones are very prominent ; the beaks are 
much inflected, and lie at about one-third the distance 
from the anterior end; in front of them is a rather large 
flattened lunule-like space, which is free from coste: the 
ligament is almost imbedded. The internal surface is 
whitish, with usually chocolate stains on the hinge-margin, 
and a tinge of brown upon the hinder termination. The 
lateral teeth are large, the front are the more approximate. 
A large specimen before us has attained the amplitude of 
five-eighths of an inch in length, and nearly half an inch in 
breadth. 

The animal partakes of the triangular form of the shell, 
and is much truncated posteriorly. The mantle is white, 
and plain in front, fringed with numerous white filaments 
about the bases of the siphonal orifices. The branchial 
aperture is larger than the anal, and surrounded by a bor- 
der of about ten filaments, as many or more tawny streaks 
radiate from it, and there is a tinge of orange or tawny 
around the other orifice also. Both are usually nearly 


sessile. The foot is long, cylindrical, and large in propor- 


BZ CARDIADA. 


tion to the body; its base is tinged with tawny, the rest 
being white. 

This species must be regarded on the whole as scarce, 
though found in many localities. Usually the number of 
specimens taken is but small. It inhabits chiefly the lami- 
narian region, and is, perhaps, rather to be considered as 
more at home in southern than in northern localities. On 
the south coast it has been taken at Southampton and 
Portsmouth (Jeffreys); Weymouth (S. H.); Dartmouth, 
in seven fathoms (M‘Andrew and E. F.); Torbay, Fowey, 
and Falmouth harbours,—at the last of which spots it is 
notable for size and frequency (Alder). Swansea (Jeffreys) ; 
Tenby (Lyons); and Milford Haven, in ten fathoms water 
(M‘Andrew and E. F.), are Welsh localities. Mr. Jeffreys 
has found it at Scalloway and Lochs Torridon and Kihon, 
on the west coast of Scotland, and Mr. M‘Andrew has 
taken it alive (a variety) in from five to ten fathoms water, 
in Balta Sound, Uist, Zetland, and dead in fifty fathoms off 
Cape Wrath. In Ireland, it has been dredged in Belfast 
and Strangford Loughs, in from four to ten fathoms on 
muddy and shelly ground (Hyndman and Thompson); and 
on the west coast, in Clew, Clifton, Killery, and Roundstone 
Bays, in from three to ten fathoms, weedy ground (R. 
Ball, W. Thompson, and E. F.); Bantry Bay and Cork 
Harbour (Humphreys). 

It does not appear to range north of Britain, but extends 
southwards to the Mediterranean, and.as far as the A gean, 
where it is plentiful in from seven to thirty fathoms water, 
usually among weeds. 

The Cardium muricatulum of authors (Monr. Test. Brit., 
p- 85,—Lin. Trans. vol. viii., p. 68,.—Woop, General Conch., 
p- 215,—Ditiwyn, Recent Shells, vol. i., p. 131,) is now 
generally regarded as the fry of this shell. It is a worth- 


CARDIUM. ao 


less species, solely constituted from a bad figure (84) in 
Walker's ‘* Testacea Minuta Rariora,” which bears about 


equal resemblance to the young of Cardiwm nodosum. 


C. surctcum, Reeve. 


Small, thin, suborbicular, very inequilateral, both within and 
without of an uniform shining pure porcelain white; ribs 
about thirty, all armed with minute vaulted scales : ventral edge 
much arcuated ; lower corners rounded. 


Plate XXXII. fig. 6. 


Cardium Suediense, REEVE (March. 1845), Conchol. Iconica, Cardium, pl. 22, f. 
132, 
»,  Loveni, THompson (May, 1845), Annals of Nat. Hist. vol. xv. p. 317, 
Dla ON fants 
“5 Suecicum, LovEN, Index Molluse. Skandinaviz, p. 36. 


The shape of this rare and exquisite addition to our 
Fauna, which was first described as an Irish production, in 
the fifteenth volume of the “ Annals of Natural History,” 
by Mr. Thompson (whose appreciation of its newness to 
science was only anticipated by two months), is somewhat 
obliquely suborbicular, the length, in the younger speci- 
mens especially, somewhat exceeding the breadth. The 
valves are very inequilateral, thin, and delicate, but opaque, 
and of a pure and uniform lustrous porcelain white. Their 
convexity is not considerable, but tolerably evenly diffused, 
a little above the central disk being the most ventricose 
portion of the shell. The surface is shining, and radiated 
with about thirty rounded and not greatly-elevated ribs, 
all of which are armed in the middle with very small and 
crowded vaulted scales, and are separated from each other 
by mere linear interstices, which become rather narrower 
near the hinder extremity, and towards the beak appear, 
under a powerful magnifier, to be minutely punctated. 


VOL. II. F 


34 CARDIADA. 


The ventral margin is arcuated in the middle, ascending 
more or less obliquely in front, and rising, although in a 
lesser degree, at the posterior side likewise. The front 
dorsal edge, in the younger examples, is very short, and 
not at all sloping, and forms a very obtuse angle with the 
but slightly convex anterior margin, which latter, as age 
advances, curves outward, when the angulation becomes no 
longer perceptible, and the front outline appears to form 
one uninterrupted sweep from the umbones to the ventral 
margin. The hinder dorsal edge is almost straight, 
almost equally devoid of declination, and forms at its ter- 
mination a more or less rounded off angle with the curved 
posterior edge. The lower corner of the hinder side, which 
is very greatly the superior in length, is likewise rounded. 
The umbones are prominent; the beaks are acute, inflect- 
ed, and lean a little towards the small and narrow im- 
pressed lunule ; the ligament is small, and not at all pro- 
jecting. The hinder dorsal area scarcely presents a trace 
of that flattening of surface so habitual in the genus; the 
umbonal ridge is consequently well rounded, and not 
strikingly manifested. The internal surface is of a pure 
unstained white, often shining with a slightly pearly lustre ; 
the front lateral teeth are the more approximate. The length 
is almost one-third of an inch, and the breadth is very 
slightly inferior. The animal appears to be entirely white. 

It is not alone the rarest of our Cockles, but one of 
our scarcer British shells, having been hitherto met 
with in scanty numbers, and out of Britain only in the 
Norwegian seas. The first recorded specimens are stated 
by Mr. Thompson to have been extracted from the sto- 
machs of some common soles (Solea vulgaris), which had 
been caught off the eastern coast of Ireland, and exposed 
for sale in the Dublin market (Dr. Farren). Subsequently, 


CARDIUM. 35 


a very few specimens were dredged off the South Rock, 
coast of Down, from the depth of fifty fathoms (Hynd- 
man); and since the publication of the species, other ex- 
amples have been obtained by Dr. Farren on the Ivish 
coast, by Mr. Jeffreys from Oban and other parts of the 
western coasts of Scotland (Ann. Nat. Hist. 1847, p. 313), 
and by Mr. M‘Andrew. The following localities, noted 
by the last-named naturalist, will serve to shew its range ; 
Loch Fyne, in thirty fathoms, alive; the Minch, in fifty 
fathoms, dead; Cape Wrath, alive, in fifty-five fathoms, 
nine miles from land; and off East Noss, Zetland, thirty 


miles from land, in seventy fathoms, alive. 


C. norvecicum, Spengler. 


Large, oblong, smooth, or nearly ribless. 


Plate XX XI. figs. 1 and 2, and (Animal) Plate N. fig. 1. 


Lister, Hist. Conch. pl. 332, f. 169. 

Cardium levigatum (not of Linnzus), PENN. Brit. Zool. ed. 4, vol. iv. p. 91, pl. 
51, f. 40.—Da Cosra, Brit. Conch. p. 178, pl. 13, f. 6.— 
PuLreney, in Hutchins, Dorset, p.31.—Donov. Brit. Shells, 
vol. ii. pl. 54.—Monr. Test. Brit. p. 80.—Linn. Trans. yol. 
viii. p. 65.—Dorset Catal. p. 31, pl. 7, f. 6—Turr. Conch. 
Diction. p. 31.—Turvr. Dithyra Brit. p. 190.—F Em. Brit. 
Animals, p. 423.— Mace. Moll. Aberd. p. 273. — 
Brown, Illust. Conch. G. B. p. 88, pl. 35, f. 12 to 15.— 
Pout, Test. Sicil. pl. 17, f. 10, 11.—Woop, General Conch. 
p- 222 (not variety), pl. 54, f. 1.—Dimiw. Recent Shells, 
vol. i. p. 123.—Mawe, Conchology, pl. 7, f. 7 (young).— 
Puripri, Moll. Sicil. vol. i. p. 50, and vol. ii, p. 37.— 
Hant. Recent Shells, vol. i. p. 133. 

Norvegicum, SPENGLER, Skrivt. Naturhis. Selskab. vol. v. part 1, p. 42. 

—LoveEn, Index Moll. Skandinayie, p. 35. 

serratum, LAM. (not Linn.) Anim. s. Vert. (ed, Desh.) vol. vi. p. 401- 
—Brit. Marine Conch. p. 99.—Turt. Dithyra Brit. p. 192, 
pl. 13, f.5 (from type). 

oblongum, Brown (not of Chemnitz), lust. Conch. G. B. p. 88, pl. 35, 
f. 16.—ReeEve, Conch. Iconica, Cardium, pl. 15, f. 71. 


3° 


” 


bh) 


36 CARDIADA. 


Cardium Pennantii, REEVE, Conch. Iconica, Cardium, pl. 9, f. 48. 
s  vitellinum, REEVE, Conch. Iconica, Cardium, pl. 7, f. 37. 


The shape of the C. norvegicum is oblique and liable to 
great modification, ranging from broadly obovate and sub- 
ventricose to subtriangular and tumid. The valves are 
very inequilateral, solid, opaque, and rather glossy, of a 
pale flesh-colour, spotted or subradiatingly speckled with a 
deeper tint of the same hue, and covered with an olivaceous 
drab or fawn-coloured epidermis, often becoming yellow 
near the margin. The surface is radiated with very 
narrow obsolete ribs, which gradually vanish in front, and 
cease upon the hinder dorsal area, which is but very mode- 
rately flattened. The ventral margin, which is but little 
rounded in the middle, is well arcuated on each side, and 
ascends rather the more obliquely and fully in front. The 
anterior side, which is very considerably the lesser one, has 
its extremity rounded both above and below, with the 
front margin curving in an almost uninterrupted sweep from 
the ventral, so that the dorsal edge is only distinguishable 
by its greater straightness. The hinder dorsal margin, 
which is the more elevated, and whose slope is moderate 
and straightish, unites with the very oblique and but little 
convex posterior edge without any angulation. The hinder 
side is also rounded, and very projecting at the lower corner. 
The ligament is large and prominent ; the umbones are nar- 
row and projecting ; and the beaks are acute and much in- 
flected, hardly leaning to either side. There is no decided 
lunule, but instead of it a somewhat undefined lanceolate 
flattened surface, which in the young is usually elevated, 
and in the fry is coloured with crimson. The obsolete 
umbonal ridge is devoid of all angularity. The interior is 
whitish or pale flesh-colour, and the ventral margin is 


coarsely dentated. The lateral teeth are rather approxi- 


CARDIUM. oie 


mate and subequidistant, the front ones are very slightly 
the more approximate and broader than the hinder ones ; 
the posterior of the left valve is very small. 

Immature individuals are far more beautiful than the 
adult, the epidermis being extremely thin and transparent, 
permitting the livid red or flesh-coloured spots or speckles 
to be distinctly visible; their interior, likewise, is often 
adorned with a dull crimson-coloured stain on each side of 
the valves. The internal rib-like elevations of the ventral 
margin are generally divided by a narrow groove. The 
most magnificent examples we have ever beheld came 
from Bantry Bay, and measured three inches in length and 
two-and-a-half in breadth. The ordinary run of specimens 
does not greatly exceed two inches in length, and one-and- 
a-half in breadth. 

We have frequently examined and delineated the animal, 
and have been favoured by Mr. Clark with his observations 
upon it. It is shaped as the shell, oval, and thick, and 
mostly of a white colour. The free edges of the mantle are 
plain, without filaments, and of a reddish-white or red-flesh 
colour, varying in intensity in different individuals, and 
bordered by white. The closed posterior portion is clothed 
with thick-set long filaments, either white, or pale yellow 
or reddish-brown. These are continued upon the slightly- 
produced siphons, which are white tinged with tawny near 
their orifices, or pale-yellow with flaky spots and lines. 
They are united at their bases, separate, and divergent at 
their extremities; the branchial tube is rather the shorter, 
though wider than the other, and has its orifice encircled 
by white cirrhi, about eight of which are longer than the 
others, and between each pair are three smaller ones. The 
anal siphon has a simple margin; a few small dark-brown 


dots surround the opening, which is furnished with a tubular 


38 CARDIAD®. 


hyaline valve; a faint brown line runs along its upper and 
lower surface. The foot is long and powerful, securiform, 
and thick, pointed at its extremity, of a red-flesh colour, 
except its apex, which is white, and a margin, as it were, 
of fulvous hue. The coloured portion presents a shagreened 
aspect under the lens, and depends upon an exceedingly 
thin epidermis which is rubbed off by the slightest touch, 
exposing pure white below it. The branchiz are of a pale 
brown colour and triangularly suboval shape, with fulvous 
or dark-brown margins and tips. The upper leaflets are 
smaller than the lower, and hang subvertically, with trans- 
verse strice more visible on the outer than on the inner sur- 
faces, being the reverse of the two palps on each side, which 
are smooth on the outer area, and striated within, trian- 
gular, very large, and pointed. 

The Cardium Norvegicum lives on a sandy or gravelly 
bottom at a depth usually of from fifteen to thirty fathoms. 
Dead valves have been taken as deep as eighty fathoms, and 
are not unfrequently cast on shore by the waves. The 
dredge and the trawl are its most efficient captors, and it 
ranges to a considerable distance from land. It is not 
habitually gregarious, often solitary. It is very active, and 
capable, by means of its large and powerful foot, of effect- 
ing considerable leaps, often springing out of the vessel 
in which it is placed when in captivity. It is so generally 
(though often sparingly) distributed around our shores that 
we must consider it a common species, and need not enu- 
merate localities, being absent from none of our local lists, 
either of eastern or western origin. Northwards it ranges 
to Norway, southwards to the Mediterranean; and as a 


fossil is known in deposits of pleistocene age. 


CARDIUM. 39 


SPURIOUS. 


Cardium Grenlandicum, CuEMn, Conch. Cab. vol. vi. p. 202, pl. 19, f. 198.— 
SpEneL. Skrivt. Naturh. Selskab. vol. v. pt. 1. p. 46.— 
SpenG. Magaz. Berlin, Gesel. Naturf. vol. ii. p. 126.— 
Woop, General Conch. p. 227.—Diiiw. Recent Shells, 
vol. i. p- 129.—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. 
p. 407.—Index Testaceol. pl. 5, f. 28.—Gouxp, Invert. 
Massach. p. 92.—H ant. Recent Shells, vol. i. p. 134.— 
Reeve, Conch. Iconica, Cardium, pl. 10, f. 53.—DEKay, 
New York Moll. p. 206, pl. 23, f. 250. 
Venus Islandica, 0. Fasr. Fauna Grenlandica, p. 411. (fide Mller.) 
Mactra radiata, Donovy. Brit. Shells, vol. vy. pl. 161.—Luyn. Trans. vol. viii. p- 
69.—Turt. Conch. Diction. p. 80.—Dimuw. Recent Shells, 
vol. i. p. 138. 
Cardium edentulum, Mont. Test. Brit. Suppl. p. 29.—Fiem. Brit. Animals, p. 
423.—SoweErby, Genera of Shells, Cardium, f. 2. 
Aphrodita columba, LA, Americ. Phil. Trans. yol. v. p. 110, pl. 18, f. 54. 


A Boreal species ; introduced by Donovan, as taken by Mr. 
Laskey, after a storm, on the shore near Portsmouth. 


C. serratum, Linneus. 


Cardium serratum, Linn. Syst. Nat. ed. 12, p. 1123.—F1xEm. Brit. Anim. p. 
423.—CuEMN. Conch. Cab. vol. vi. p. 193, pl. 18, f. 189. 
—Ditiw. Recent Shells, vol. i. p. 124.—Mawe, Concho- 
logy, pl. 7, f. 2—Hanu. Recent Shells, vol. i. p. 133.— 
Reeve, Conch. Iconica, Cardium, pl. 1, f. 1. 
is citrinum, Woop, General Conch. p. 223, pl. 54, f. 3. 
»  levigatum, SPENGLER, Magaz. Berlin Gesel. Naturf. vol. ii. p. 125.— 
Brit. Marine Conch. p. 99.—Lam. Anim. s. Vert. (ed. 
Desh.) vol. vi. p. 4038. 


A West Indian shell, introduced by Dr. Fleming, as from the Pent- 
land Frith, under the natural supposition that it was identical with 
Turton’s species. The latter is a young variety of Norvegicum. 


©. mepium, Linneus. 


Cardium medium, LINN. Syst. Nat. p. 1122.—Downov. Brit. Shells, vol. i. pl. 32, 
f. 1.—Monr. Test. Brit. p. 83.—Linn. Trans. vol. viii. p. 
61.—Tourvt. Conch. Diction. p. 32.—FLxem. Brit. Anim. p. 


40 CARDIADA. 


422,—CueEmn. Conch. Cab. vol. vi. p. 169, pl. 16. f. 162, 
163.—Woop, General Conch. p. 21], pl. 50, f. 3.—Lam. 
Anim. s. Vert. (ed. Desh.) vol. vi. p. 409.—Di~iw. Recent 
Shells, vol. i. p. 118.—Mawez, Conchology, pl. 7, f. 1.— 
Hant. Recent Shells, vol. i. p. 141.—ReEEve, Conch. Iconica, 
Cardium, pl. 6, f. 30. 


A West Indian shell ; introduced by Donovan as taken near 
Hartlepool, on the coast of Durham. The small specimen, with 
about fifty (1) ribs, stated in Turton’s Dithyra (copied at p. 78 of 
the British Marine Conchology) to have been taken alive at Liver- 
mead, near Torquay, is evidently not this shell, and was, in all 
probability, only the young of Venus ovata, the fry of which 
closely resembles a small Cockle. Unfortunately, the original speci- 
men is lost, and the description is inadequate for the determination 
of the species. In some local collections we find Cardium pyg- 
mum preserved under this name. 


C. muricatum, Linnzeus. 


Cardium muricatum, Lixsnzus, Syst. Nat. ed. 12, p. 1123.—Fremrne, Brit. 
Anim. p. 421.—CueEmn. Conch. Cab. vol. vi. p. 185, pl. 
17, f. 177.—Brucurere, Enc. Méthod. Vers. vol. i. p. 
233.—Woop, General Conch. p. 216, pl. 51, f. 2, 3.— 
Dittw. Recent Shells, vol. i. p. 120.—Lam. Anim. s. 
Vert. (ed. Desh.) vol. vi. p. 399.—Index Testaceolog. pl. 
5, f. 14.—Hanuey, Recent Shells, vol. i. p. 132, pl. 5, f. 
14.—Reeve, Conch. Icon. Cardium, pl. 6, f. 33? 


A West Indian shell ; introduced by Dr. Fleming, who received 
it from Dr. Coldstream as found at Leith, in Scotland. It had 
probably been transported in ballast. 


Al 


LUCINID. 


Tue mollusks composing this group exhibit shells which, 
in form, texture, and ornament, strikingly remind us of 
Venus and its tribe, whilst the animals seem more closely 
connected with Kellia and its minute allies. The former 
are equivalve, and usually more or less orbicular, their sur- 
faces presenting all varieties of sculpture; in some being 
smooth, in others decussated or radiated by longitudinal 
ribs, or suleated by concentric furrows, or scored by wavy 
markings disposed in elegant and regular patterns. The 
muscular scars of their interiors present features of generic 
importance, and the pallial impression is always entire. 
The animals have sessile siphons, unless the anal tube pre- 
sented by certain Lucine be regarded as a true siphon; 
more probably, however, it is only a great development of 
the anal valve. They are sand or mud-inhabiting bivalves, 
ranging through all depths of water, some of them being 
littoral, others confined to the deepest explored abysses of 
the ocean. The genus Corbis, of which we have no living 
British examples, though during periods immeasurably dis- 
tant its representatives inhabited our area, is a very beauti- 
ful and conspicuous member of this tribe. 

The animals of several species of Lucina and that of 
Corbis, have furnished the subject of some valuable ob- 
servations communicated by the eminent French zoologist, 
Valeuciennes, to the Institute in 1845, and published in 


VOL. II, G 


42 . LUCINIDA. 


the “Comptes rendus” for that year.* ‘The family of 
Lucine,” he states, ‘is composed of mollusca which have 
only a single branchial leaflet on each side of the visceral 
mass, and of the foot. ‘This single branchia resembles that 
of the Anodonta; it is large, thick, and formed of pec- 
tinated and anastomosing lamelle.” This peculiarity was 
first observed by M. Valenciennes in the Lucina Jamai- 
censis, afterwards in Lucina tigerina (so long considered a 
Venus or Cytherea); also in Lucina columbella and in 
Lucina lactea. An examination of the animal of Corbis 
shewed that it also presented this curious feature, but was 
distinguished from Lucina by its non-perforated foot. He 
further discovered that in the Lucine the aperture of the 
mouth is very small, and surrounded with weak and thin 
folds of skin, being rudimentary lips. He confirmed the 
statements of Poli respecting the singular structure of the 
foot, and completed his description. ‘“ This foot,” he states, 
“is a fleshy cylinder, folded back on itself so as to be 
hidden between the plates of the mantle of the mollusk, for 
it is frequently twice as long as the diameter of the animal. 
When not contracted, it is much longer. It is remarkable, 
that it is hollow throughout its entire length, and that this 
tube opens directly and widely into the spaces of the 
visceral cavity.” There can be little doubt that the single 
gill accorded by M. Valenciennes is an organ similar to that 
observed by Professor Owen in Pholadomya and Anatina, 
viz., the two lamelle of the same side so united as to 
appear like a single gill. 

In conformity with general opinion, we place the genus 
Diplodonta, the species of which closely resemble, and were 
formerly associated with Lucina in this family, though, as 


* See also “ Annals of Nat. History,” vol. xvi. p. 41, where the paper is well 
translated. 


LUCINA. 43 


will be seen hereafter, it differs in having the branchial 
lamellz not united on each side, and the labial palps fully 
developed. 


LUCINA. Bruciere. 


Shell equivalve, orbicular, sub-compressed or tumid, 
regular, often nearly equilateral ; surface smooth or con- 
centrically striated, or ribbed in one or both directions, or 
marked with undulating or angular furrows; hinge very 
variable, usually presenting two diverging cardinal teeth 
and two laterals, but in many species one or both sets of 
teeth are more or less obliterated; ligament varying in 
position, chiefly external; muscular scars strongly marked, 
the anterior usually elongated ; pallial impressions simple. 

Animal orbicular, its mantle freely open in front, with 
plain or fimbriated edges; siphonal orifices sessile, the anal 
sometimes (always‘) provided with a retractile produced 
tube (anal valve’). Foot very long, ligulate, tubular. 
Branchial leaflets of each side united into one ; labial palps 
obsolete. 

The assemblage of shells to which the name Lucina has 
been given by conchologists includes so many species, pre- 
senting striking dissimilarities in dentition and seulpture, 
that we are naturally tempted to separate them into distinct 
generic groups, and many appellations of proposed generic 
value have been given to their several supposed types. Un- 
fortunately, however, our knowledge of the animals of the 
so-called Lucine is by no means commensurate with our 
acquaintance with their shells, and all that we do know 
would rather seem to warn us against the proposed divisions 
than to bear them out. It appears as if many important 
characters, which in other families afford almost unfailing 


44 LUCINIDA. 


sources of generic distinction, had in this been degraded to 
a specific position, and that features, usually of little con- 
sequence, had usurped their places. Until our knowledge 
of the tribe becomes much more minute and accurate 
than it now is, conchologists had better content themselves 
with using a single generic term, than, through a false am- 
bition of becoming the parents of names, thrust worth- 
less and embarrassing synonyms on a science already con- 
siderably encumbered with rubbish. 

As far as external aspect goes, our British Lucine arrange 
themselves under several sections. Thus, Lucina borealis, 
the type of the genus, naturally associates itself with Z. 
spinifera (which constituted the useless genus Myrtea of 
Turton). To this section, in which, so far as we know, the 
animal does not exhibit a prolonged anal tube, the name 
Lucina most especially belongs. The Lucina lactea, and 
its Mediterranean allies, nearly resemble the former; but 
appear to have, judging from the figures of Poli and 
Deshayes, a very much prolonged anal valve, or tube—this 
is the section Loripes. The Lucina flexuosa appears to 
have a very similar animal, though we have not observed 
its tube; its shell exhibits peculiarities of dentition which 
caused Turton to constitute his genus Ovryptodon, Phi- 
lippi his Péychina, and Leach his Thyasyra. The fossil 
generic name Awinus had been given by Sowerby to a 
Lucina evidently of this group, from the London clay, 
though, asin many fossil genera, the founder seemed to have 
had a very indistinct notion as to wherein its generic claims 
and affinities lay. Generic names so founded can scarcely 
claim right of priority, any more than those of manuscript 
catalogues, such as the frequently quoted lists of Leach, 
the publication of one of which by Mr. Gray in the “ Annals 
of Natural History,” has not increased, but rather diminish- 


LUCINA. 45 


ed the confidence of naturalists in their value. Clausina* 
of Jeffreys can scarcely claim separation from the section 
Cryptodon, though the minute shell for which it was found- 
ed presents striking resemblances to a Kellia. Lucina 
divaricata forms part of the genus Strigilla of Turton, and 
marks a section curious for the wavy lines sculpturing the 
surface of the shells it includes. Lastly, the pseudo- 
British L. tigrina, with its allies, constitute an assemblage 
equally remarkable for singularities of sculpture, but not 
the less presenting the essential and peculiar characters of 
Lucine. The name Codakia of Scopoli applies to this 
subdivision. 

Lucine are distributed all over the world, and between 
thirty and forty existing species have been described. 
Nearly 150 fossil species are recorded from various forma- 
tions, and they distinctly commenced their appearance 
early in the secondary epoch, and probably sooner. The 
elongated muscular scar is an excellent guide in determining 
casts of fossil Lucine, though itself by no means so constant 
in character throughout the genus as we could wish it to 


be. 


* The characters of his genus Clausina, as given by Mr. Jeffreys himself in 
the twentieth volume of the Annals of Natural History (July 1847) are as 
follows :—“ Testa pygmeea, orbicularis aut longitudinaliter rotundato-oyata, glo- 
bosa, subzequilateralis, zequivalvis, utrinque clausa, plerumque tegumine ferruginoso 
vestita. Cardo in utraque valvula tuberculo et lamella laterali munitus. Apices 
subcentrales ; lunula nulla; ligamentum externum. Impressiones musculares ut 
in Cyprina.” Mr. Gray has strangely placed it among his Tedlinide. 


46 LUCINID. 


L. sorrarts, Linnzeus, 


Suborbicular ; with raised concentric striz. 


Plate XXXV.., fig. 5, and (Animal), Plate M. fig. 6. 


Venus borealis, Linn. Syst. Nat. ed. 12, p. 1134 (from type).—Donov. Brit. 
Shells, vol. iv. pl. 130. 
Tellina radula, Mont. Test. Brit. p. 68.— Linn. Trans. vol. viii. p. 54.—Turt 
Conch. Diction. p. 175.—Woop, General Conch. p. 183, pl. 
42, f. 4, 5.—Index Testaceolog. pl. 4, f. 71. 
Lucina radula, Lam. Anim. gs. Vert. (ed. Desh.) vol. vi. p. 225. — Turt. 
Dithyra Brit. p. 116.—Frem. Brit. Anim. p. 441.—Mac- 
cinuiy. Moll. Aberd. p, 255.—Brit. Marine Conch. p. 73.— 
Brown, Illust. Conch. G. B. p. 98, pl. 39, f. 8, 9— PHILIPPI, 
Moll. Sicil. vol. i. p. 35, pl. 3, £17, and vol. ii. p. 25. — 
Goutp, Invert. Massach. p. 69.—Hant. Recent Shells, p. 75. 
3 alba, (Younc) Tur. Dithyra Brit. p.114, pl. 7, f. 6, 7.— Brit. 
Marine Conch. p. 72. 
a antiquata, (Foss1L) Sow. Min. Conch. pl. 557, f. 2. 


The substitution of the name borealis for the better 
known appellation of radula, is the result of an investi- 
gation of the Linnzan species, still preserved in the cabinet 
of the illustrious naturalist of the north. The contour of 
this thread-girt bivalve is very nearly orbicular, the length 
of the shell scarcely exceeding the breadth in the slightest 
degree. The valves, which are rather ventricose in the 
middle, but rapidly diminish in convexity towards the mar- 
gin, and chiefly anteriorward, are of an uniform more or 
less pure white, and are covered in the adult with a deli- 
cate yellowish or ash-coloured epidermis. Acute mem- 
branaceous strie, which are rather closely arranged in a 
concentric direction, and are more or less equidistant, ren- 
der the entire surface rough to the touch; the interstitial 
spaces are not decussated, and there is no other sculpture 
or division of surface present, excepting an obscure shallow 
sulcus along the ordinary site of an umbonal ridge. The 


LUCINA. 47 


ventral margin is strongly arcuated, and usually, but not 
invariably, rises rather the more in front, thus causing the 
anterior side to be rather the less broad. The front dorsal 
edge is more or less retuse, and declines in but a trifling 
degree; the hinder dorsal edge is nearly straight, or hardly 
convex, and scarcely slopes at all. The anterior side, 
which exhibits a rounded off angle above, but not the 
slightest angulation below, is decidedly, but not so very 
greatly, the shorter; the posterior side is angulated above, 
and, similarly to the other side, is destitute, except in 
young individuals, of any inferior angulation. The um- 
bones project but little; the beaks are acute, and lean a 
little forward; in front of them is a shallow lanceolate 
lunule. The ligament is broad and large, but not promi- 
nent, and is usually of a rather pale colour. The internal 
surface is of a more or less dull white; the hinder muscular 
scar is very large, and the margin perfectly free from crena- 
tion. There exists in each valve a bifid and a simple primary 
tooth, both of which are of moderate size ; and in the right 
valve a very small not very distant anterior lateral one, 
which, however, is often very obscure. 

The breadth of a fair-sized specimen was an inch and a 
half, which measurement was very slightly exceeded by its 
length. 

We are indebted to Mr. Alder for a sketch of the 
animal of this species, one of the many obligations con- 
ferred on us by our much valued friend. It is accompanied 
by the following note: “I enclose you a drawing of Lucina 
borealis, made from specimens sent me by Mr. Embleton. 
During the ten days I kept them alive, they shewed no 
more than I have represented, from which I conclude that 
the two siphons are never exserted. The mantle is widely 


open in front, with the margins waved or plicated ; there 


48 LUCINIDA. 


are two apertures behind, the upper one of which is the 
largest, but they do not appear to be produced into tubes, 
or exserted beyond the shell. The foot is long and strap- 
shaped or cylindrical in front, and capable of great ex- 
tension ; behind it is strong and slightly lunate. (The out- 
line shews this as it appears when the shell is opened.) 
There is only a single branchial leaflet on each side. Rang 
says, that the mantle is fringed, but as far as I can see there 
are no filaments; he also says ‘tubes courts et réunis,’ 
which does not agree with this species.” 

This is by no means a common shell, though widely dis- 
tributed around our coast, and in certain localities very 
abundant. It inhabits sandy ground in various depths, 
from near low-water mark down to ninety fathoms. In 
the south it cccurs abundantly near St. Peter’s Port in 
Guernsey (S. H.); Exmouth (Clark); Falmouth and 
other parts of Cornwall (Jeffreys and Alder); Scilly Isles 
(M‘Andrew) ; Bristol Channel (Jeffreys) ; Milford Haven 
(M‘Andrew and E. F.); Isle of Man in from twelve to 
twenty-five fathoms, and plentiful in places, as at Ballaugh 
and Derbyhaven (E. F.); Scarborough (Bean) ; Embleton 
Bay, Northumberland, at low water, plentiful (Embleton). 
In Scotland it occurs at Oban, and in many of the lochs 
of the Hebrides (Jeffreys) ; on the Zetland coasts frequent 
in muddy sand, from fifteen to nmety fathoms, and as far 
as thirty miles from shore (M‘Andrew and E. F.) ; Moray 
Firth in from fifteen to thirty-four fathoms (M‘Andrew) ; 
beyond low-water mark in sand at Stromza, Sanda, and 
elsewhere in the Orkneys (Thomas) ; Aberdeenshire (Mac- 
gillivray). ‘ Widely distributed around the coast of Ire- 
land, dredged in sand in from six to twelve fathoms in 
Belfast and Strangford loughs. Found by myself and Mr. 
R. Ball, in lakes of brackish water in largest of south isles 


LUCINA. 49 


of Arran 1834.” (W. Thompson). Off Cape Clear in sixty 
fathoms (M‘Andrew); Bantry Bay and Cork Harbour 
(Humphreys, Barlee). 

Tt ranges to Finmark, and may be regarded as a cha- 
racteristic Celtic shell. It is found fossil in both red and 
coralline crags, so can boast of a high antiquity within the 
British area. Gould enumerates it among the rarest shells 
of Massachusetts. Its comparative abundance on the 
eastern side of the Atlantic, and its presence there in an- 
cient deposits, would seem to indicate that region as its 
place of birth as a species. 


L. sprntrera, Montagu. 


Oval ; with raised concentric strie, which become spinous at 
the hinder dorsal termination. 


Plate XX XV. fig. 1. 


Venus spinifera, Mont. Test. Brit. p. 577, pl. 17, f. 1.— Linn. Trans. vol. viii. 
p- 78. — Tur. Conch. Diction. p. 231. — Ditiw. Recent 
Shells, vol. i. p. 163.—Index Testaceolog. pl. 7, f. 11. 


Myrtea 5, Turt. Dithyra Brit. p. 133.—Fiem. Brit. Anim. p. 433.— 
Brown, Illust. Conch. G. B. p. 98, pl. 36, f. 15, 16, and 
pl. 39, £. 14. 


Ineina Hiatelloides, Putripri, Moll. Sicil. vol. i. p. 32. 
»  spinifera, Brit. Marine Conch. p. 74, f. 23.—Maceiniiy. Moll. Aberd. 


p- 255. ?—Hant. Recent Shells, vol. i. p. 78.—Puiiprt, 
Moll. Sicil. vol. ii. p. 25. 


There exists in the dorsal aspect of this elegant bivalve, 
its large and elongated ligament guarded with minute and 
crowded spinous projections, a facies which readily distin- 
guishes it from its congeners, whether of native or foreign 
nativity. As to the general shape and sculpture, these are 
liable to extraordinary modification. Typically, the former 
may be stated to be oval, ranging through oboval to 
somewhat triangularly suborbicular ; the length, however, 


VOL. II. H 


50 LUCINID A. 


most decidedly exceeds the breadth in all the numerous 
examples we have hitherto observed. The valves are 
rather strong, opaque, and of an uniform lustreless white ; 
when young they are compressed, but in the more aged 
individuals are subcentrally (or rather higher than the 
middle of the disk) almost ventricose, rapidly diminishing, 
however, in convexity towards the margins. The surface 
is concentrically wrought with numerous extremely deli- 
cate laminar strie, which typically are almost equidistant, 
and cover the entire area, but in some examples approxi- 
mate towards the lower margin, or become obsolete upon 
the more swollen portion of the disk; occasionally too 
they are extremely fine and depressed, and most crowdedly, 
and sometimes irregularly disposed. These membranaceous 
lines (whose interstices are not visibly decussated), ab- 
ruptly ceasing near the hinder dorsal edge, surround the 
smooth and flattened or slightly excavated lozenge (which 
is lanceolate, and pointed at both extremities) with a 
crest of small spinous protuberant scales formed in the 
younger specimens, and in the upper portion of the adult 
ones, by the confluence of each pair of strie at their ter- 
mination. The ventral margin, which is internally some- 
what flattened and devoid of crenation, is moderately 
arcuated, and rises the more in front; its chief swell is a 
little before the middle. The dorsal edges vary from 
rather slightly to moderately sloping; the hinder one is 
convex, the front one is decidedly incurved. The um- 
bones project but little, and are usually rather compressed 
towards the very small beaks, in front of which lies a rather 
large lanceolate sunken smooth-surfaced lunule. The ante- 
rior side is rather the shorter ; its extremity, which is sub- 
angulated above, and well rounded below, is about equal 
in breadth to the subtruncated posterior termination ; the 


LUCINA. 51 


short posterior margin, which is more or less straight and 
perpendicular, forms a decided angle with the upper, and a 
rounded off one with the lower margin. The ligament is 
ochraceous, and by no means prominent. The interior is 
white, or more rarely tinged with yellow; the primary 
teeth are almost rudimentary ; there is a distinct slightly 
approximate anterior lateral, and a less developed distant 
posterior one. 

The measured length of a large Scotch example was an 
inch and an eighth; its breadth, seven-eighths of an inch. 
The Mediterranean specimens are vastly inferior in size, 
and are usually tinged with a warmer colouring. 

The animal appears to be white; the tubes not pro- 
duced ; the mantle freely open ; the foot long, cylindrical, 
very slender, and not swollen, clavate at the extremity. 
We have never examined this creature when alive. 

This local species, an inhabitant chiefly of our western 
oceanic shores, inhabits sandy, muddy, or weedy ground, 
in various depths of water, between eight and one hundred 
fathoms. It is rare in the south, though occurring off 
Dartmouth in twenty-seven fathoms, and Plymouth in 
twenty-eight fathoms (M‘Andrew and E. F.) ; Torquay 
(Battersby); and Salcombe (Montagu). We are not 
acquainted with any other English localities for it. On 
the Scottish coast it is more frequent, and often plentiful, 
as at Oban, in fifteen fathoms, mud; Lismore, in twenty 
fathoms ; Raza, in thirty fathoms; Mull, in ninety fa- 
thoms ; the Zetlands, in from eighteen to eighty fathoms ; 
and far from land as well as near the coast ; the Moray 
Firth, in thirty-four fathoms (M‘Andrew and EK, F.) ; 
‘“ Hebrides in many places, and coast of Ross-shire ” 
(Jeffreys). Mr. Macgillivray enumerates it among his 
shells of Aberdeenshire, but the identity of his specimens is 


52 LUCINID&. 


questionable, since he remarks, that it appears to him to be 
‘almost certainly the young of Z. radula.” In Ireland it 
is abundant in the bays of the Connemara coast, in from 
eight to eighteen fathoms; Birterbuy Bay and Arran 
Island (Barlee) ; Red Bay, county Antrim, and Dublin 
coast (Thompson) ; Cork harbour (Humphreys); Bantry 
Bay (Miss M. Ball); off Cape Clear, in sixty fathoms 
(M‘Andrew). 

Abroad it ranges northward to Bergen, in Norway, and 
southward throughout the Mediterranean. 


L. prvaricata, Linneus. 


The strize diverging from each other at obtuse angles. 


Plate XX XV. fig. 3. 


Tellina divaricata, Linn. Syst. Nat.ed. 12, p. 1120.—(not Turr. Conch. Diction. 
p- 178.)—Sprncuer, Skrivt. Naturh. Selskab. vol. iv. part 2, 
p- 117 (mot vars). 

Cardium arcuatum, Mont. (not Reeve), Test. Brit. p. 85, pl. 3, f 2. — Linn. 


Trans. vol. viii. p. 67.— Woop, General Conch. p. 213. 
Lucina arcuata, Fuxem. Brit. Anim. p- 442. 


% commutata, Puitipri, Moll. Sicil. vol. i. p. 32, pl. 3, f. 15, and vol. ii. 
p. 25. 
re divaricata, Brit. Marine Conch. p. 76. 


This is not the divaricata of Chemnitz, Gmelin, and the 
mass of writers, but, as Dr. Philippi suggests, the original 
one indicated by Linnzeus in his Systema as an inhabitant 
of the Mediterranean. 

The shape is rather obliquely suborbicular, the breadth a 
little exceeding the length; the valves are ventricose, and 
occasionally even inflated, opaque (possibly from being only 
dead specimens), of a dull white, and marked not only with 
antiquated lines of growth, but with very crowded sub- 


imbricated and somewhat radiatingly-divergent striule, 


LUCINA. 53 


which form very obtuse angles a little before the middle, 
whence they bend backwards with a slight retusion, and a 
trifling declination. In the largest example we have seen 
the subcentral angles are replaced towards the lower edge 
by somewhat flexuous striule, which are arcuated in a 
direction contrary to the concentric lines of growth. In 
this shell, too, although the striule extend to the hinder 
extremity, they are interrupted in front upon the upper 
dorsal area (which is somewhat flattened), by bemg broken 
into several minute and extremely short zigzags, but ter- 
minate, however, in their original subretuse downward 
inclination. 

The ventral margin is excessively arcuated, and ascends 
rather the more behind. The posterior side is the shorter, 
and appears very high-shouldered, owing to the extremely 
trifling declination of its but slightly convex dorsal edge ; 
the upper corner is broadly subangulated. The front dorsal 
edge is likewise but very moderately sloping ; it is short, 
and forms a very wide angle with the rather straightish 
upper part of the anterior edge. Both extremities are 
rounded below. The umbones do not greatly project, but 
the beaks are very acute, lean considerably forward, and 
are preceded by a small but distinct oblong lunular de- 
pression. ‘The ligament is not conspicuous externally, and 
there is no dorsal depression around its site. The hinge of 
the right valve is furnished with a single primary tooth, 
that of the left with two; there are, moreover, two lateral 
lamine in both valves. ‘The inner margin, when viewed 
by the lens, appears most delicately crenulated ; the front 
muscular scar is short and oblong. 

Montagu’s own specimen (still in our National Mu- 
seum) is the largest we know of, measuring nearly half an 
inch in breadth, and rather less in length. The only other 


54 LUCINIDA. 


British example we have seen was dredged by Mr. Jeffreys, 
in twenty fathoms, at St. Mawe’s Creek, five miles from 
Falmouth; the same locality from whence the original 
specimen was procured. Both shells greatly surpass the 
ordinary dimensions of the Mediterranean ones. 

Poli’s figure (Test. Sicil. vol. 1, pl. 15, f. 25) and de- 
scription of this shell are by no means characteristic, and 
appear to have been modified from a fancied identity of 
his species with the larger West Indian Lwcina, usually 
known by the name we have applied to the present shell. 
The valves of Strigilla divaricata, stated by Turton (Di- 
thyra Brit. p. 120) to have been picked up on Teignmouth 
Beach, belong to the Transatlantic mollusk, 

(Tellina divaricata, CHEMN. (not Linn.), Conch. Cab. vol. vi. p. 134, (not var.) 
pl. 138, f. 129.—Turv. Conch. Diction. p. 178. —Woon, 
General Conch. p. 195, pl. 46, f. 6.—Di_iw. Recent Shells, 
vol. i. p. 102.—Index Testaceolog. pl. 4, f. 87. 

Lucina divaricata, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 226. — BLAINy. 


Man. Malacolog. pl. 72, f. 3. — Gouxp, Invert. Massach. 
p. 70.—DrxKay, New York Moll. p. 214, pl. 26, f. 273.) 


and are correctly described as only ‘rather convex,” with 
their striz ‘not very close,” “‘ the margin plain,” &e. 


L. rtexvosa, Montagu. 


Thin, semipellucid, smooth; a radiating sulcus from the beaks 
to the hinder extremity. 


Plate XXXYV. fig. 4. 


Venus sinuosa, Donoy. (not Pennant,) Brit. Shells, vol. 11. pl. 42, f. 2. 

Tellina flecuosa, Mont. Test. Brit. p. 72.—Linn. Trans, vol. vill. p. 56.—Turv. 
Conch. Diction. p. 177. —Woop, General Conch. p. 188, pl. 
47, f. 7, 8. — Dittw. Recent Shells, vol. i. p. 100. — Index 
Testaceolog. pl. 4, f. 78. 

Amphidesma flexuosa, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 128. 

Lucina sinuata, LAM. Anim. s, Vert. (ed. Desh.) vol. vi. p. 280.—HANL. Recent 
Shells, vol. i. p. 77. 


LUCINA. 55 


Cryptodon ficauosum, Turt. (not of Moller, from type) Dithyra Brit. p. 121, 
pl. 7, f. 9, 10. — Maceitniy. Moll. Aberd. p. 278. — 
Brown, Llust. Conch. G. B. p. 99, pl. 39, f. 4, 5. 

Lucina flexuosa, Fie. Brit. Anim. p. 442. 

Ptychina biplicata, Putirrr, Moll. Sicil. vol. i. p. 15, pl. 2, f. 4, and vol. ii. 

p. ll. 
Lucina flexuosa, Goutp, Invert. Massach. p. 71, f. 52. 
»  sinuosa, Brit. Marine Conch. p. 74. 
Axinus flecuosus, LovVEN, Index Moll. Skandin. p. 38.—Kuine, Ann. Nat. Hist. 
vol. xviii. p. 242. 


This delicate and fragile bivalve is of a distorted subor- 
bicular shape, very inequilateral, and manifestly broader 
than it is long. It is very thin, more or less ventricose, 
almost pellucid, slightly glossy, and both externally and 
internally of a pure or bluish-white ; the surface is almost 
smooth, or is merely concentrically traversed with obsolete 
subpliciform wrinkles, or lines of growth. The peculiar 
characteristic features are evidently the somewhat angular- 
ly flexuous outline, and the posterior sulcus. This latter, 
emanating from behind the umbones, and running adjacent 
(but not parallel with, for it inclines more inwards) to the 
dorsal edge, is rather broad at its termination where it en- 
larges, and induces a very distinct incurvation of the pos- 
terior outline towards the middle of the hinder side. Above 
this there is occasionally also a retusion near the end of the 
dorsal margin, which slopes with but moderate declination, 
and trifling convexity. The front dorsal edge slopes re- 
tusely and very decidedly downward, forming rather more 
than a right-angle with the greatly rising and little convex 
anterior part of the ventral margin; which latter, in the 
adult shell (for immature individuals are far less angular in 
outline) appears, owing to its abrupt ascent and similar 
want of convexity behind, to display subcentrally a round- 
ed-off angle; its posterior rise is, however, less marked, 
and there is no distinct angle at its cessation. The anterior 


56 LUCINID&. 


side is very considerably the smaller and the narrower one. 
The umbones are rather prominent, and incline forwards ; 
the beaks are small and acute ; in front of them is a rather 
large not very profound subovate lunule. The ligament is 
partially concealed by the overlapping margins. There is 
a single erect obscure primary tooth in the right valve: the 
anterior muscular impression is double. 

The average breadth of specimens is about three-eighths 
of an inch, and the length is somewhat less. There is a 
closely-allied Swedish shell, the Avinus Sarsit of Philippi 
(Loven, Ind. Moll. Skandinay. p.38), which differs in being 
larger, more orbicular, less angular in contour, almost 
opaque, devoid of the cardinal denticle, having its lunule 
almost obsolete, and the front angle perfectly so. 

The animal, judging from a specimen preserved by Goad- 
by’s fluid, is of a white colour, and has a widely-gaping 
mantle, with two orifices, but no appearance of prolonged 
tubes posteriorly. The foot is very long, almost filiform, 
cylindrical, tubular, and presents a clavate extremity. 

This beautiful shell is widely distributed around our 
shores; though, from its delicacy and fragility, and the 
facility with which the valves separate, perfect specimens 
are comparatively rare in our cabinets. Mud, or muddy 
sand is its favourite bottom, and in some places it is found 
on such ground in considerable numbers. Among its locali- 
ties may be enumerated,— Weymouth, in seven fathoms, 
and Dartmouth, im nine fathoms (M‘Andrew and E. F.) ; 
Exmouth (Clark); Torbay (Alder and S.H.); Falmouth, 
and other parts of Cornwall (Jeffreys and Alder); Coast of 
Glamorganshire (Jeffreys); Tenby, where single valves are 
very abundant (S. H.); Anglesea (M‘Andrew); Isle of 
Man, twelve fathoms, but rare (EK. F.); Scarborough 
(Bean); Coast of Northumberland and Durham (Alder). 


LUCINA. 57 


Occasionally on the fish-lines, twenty-five miles east of Fern 
Islands, in thirty fathoms (King, Ann. Nat. H. vol. xviii.). 
In Scotland it is plentiful in the Clyde (Smith and E. F.), 
especially around Arran, and many localities of the imner 
and outer Hebrides (Jeffreys); Skye, in forty fathoms, 
mud; Zetland, alive, in four, seven, fifteen, seventy and 
eighty fathoms (M‘Andrew and KE. F’.); and at Deal Voe, 
in twenty fathoms (Jeffreys); Aberdeenshire (Macgil- 
livray). ‘It occurs on each side of the Irish Coast ; 
dredged in Strangford Lough on sand and mud, from ten 
to twenty fathoms, by Mr. Hyndman and myself” (W. 
Thompson), In various localities on the West Coast of 
Treland, as at Clew and Killery, in from three to ten 
fathoms (Thompson, R. Ball, and E. F.); Dublin Bay 
(Alder); Bantry (Humphreys); Youghal (R. Ball); Cape 
Clear, in thirty fathoms (M‘Andrew). 

Abroad, it ranges northwards to Finmark, and south- 
wards to the Mediterranean. As a fossil it is found in 
some of the Scottish glacial beds (Smith), and in the crag 
(S. V. Wood). 


L. tevcoma, Turton.* 
Opaque, devoid of all sculpture ; no external ligament. 


Plate XXXYV. fig. 2 (as LZ. lactea). 


Tellina lactea (not of Linn.), PULTENEY, in Hutchins’ Hist. of Dorset, p. 30.— 
Mont. Test. Brit. p. 70.—Linn. Trans. vol. viii. p. 56.—Dorset 
Catalog. p. 30, pl. 5, f. 9. —Turr. Conch. Diction. p. 176.— 
Woop, General Conch. p. 187.—Ditiw. Recent Shells, vol. i, 
p: 99.—Index Testaceolog. pl. 4, f. 76. 


* This not being the Zucina which Linneus intended to indicate under the 
appellation of Tellina lactea, we have reluctantly changed the name to that which 
Turton bestowed upon a shell so precisely identical (we have compared his own 
specimens) that we cannot even term it a variety. 


VOL. II. 1 


58 LUCINID&. 


Lucina lactea, LAM. (not Philippi), Anim. s. Vert. (ed. Desh.) vol. vi. p. 229 
(chiefly). — Turr. Dithyra Brit. p. 112, pl. 7, f. 4, 5. — Brit. 
Marine Conch. p. 71. — Brown, Illust. Conch. G. B. p- 98, 
pl. 39, f. 8.—Hant. Recent Shells, vol. i. p. 76. 
»  Amphidesmoides, DESH. Encyclop. Méthodique, Vers. vol. ii. p. 375. 
Amphidesma Lucinalis, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 127 (fide 
Philippi). 
Lucina leucoma, Turt. Dithyra Brit. p. 113, pl. 7, f. 8. — Brit. Marine Conch. 
p- 72. 
Loripes lactea, Fumm. Brit. Anim. p. 430.—Macerty. Moll. Aberd. p. 256 ?— 
Brown, Illust. Conch. G. B. p. 98, pl. 39, f. 29. — BLarnv. 
Manuel Malacolog. pl. 72, f. 1. 


The shape of this shell is very nearly orbicular, and the 
valves rather strong, opaque, almost entirely devoid of 
lustre, and of an uniform white both within and without. 
They are almost equilateral, convex, and usually more or 
less ventricose at the umbonal region, where the chief swell 
exists, diminishing gradually and tolerably evenly from 
thence towards the margins. The surface, which appears 
peculiarly liable to indentations, is not striated, nor yet 
quite smooth, but is concentrically traversed by antiquated 
lines of growth. The upper front corner of the adult is pe- 
culiarly compressed, as an extremely indistinct very shal- 
low and rather broad sulcus, emanating from the beaks, 
runs close to the dorsal edge, and slightly indents the upper 
part of the front margin at its extremity. The ventral or 
lower outline is moderately arcuated, and rises rather the 
more in front, which occasionally (for it varies in extent) 
gives an air of obliquity to the contour ; it is not flattened 
on either side, though it is usually rather the more curved 
behind. The anterior side is rather the shorter, and de- 
cidedly the narrower. Both dorsal edges decline in but a 
very trifling degree ; the hinder, which is rather the higher, 
is almost straight, or but slightly convex, the front one, 
which is rather the more sloping, after passing the lunule, 
becomes a little convex likewise. Both extremities are 


LUCINA. 59 


rounded below, and obscurely subangulated above. The um- 
bones are but moderately prominent, and incline forwards ; 
the beaks are small and inflected; in front of them is a 
very short, not deeply impressed, lunule. The cartilage, 
which is large and of a darker colour, occasionally of a 
reddish-orange, is very obliquely seated in a groove of the 
hinder hinge margin; which latter is rather broad, and 
gradually sinks inwards as it nears the posterior extremity. 
There are no distinct lateral teeth, though sometimes a 
rudimentary front denticle is found in the right valve, 
which is furnished with a single primary tooth ; in the left 
valve the cardinal teeth are two in number, but remark- 
ably small in size. The muscular scars are very large; the 
front one, which is peculiarly narrow and elongated, runs 
nearly parallel to the front of the palleal impression. 

The measured diameter of rather a large example was 
exactly three-quarters of an inch. There is a dwarf ven- 
tricose variety, taken chiefly at Guernsey (S. H.), of only 
half an inch in length, and rather less in breadth, where- 
in the hinder dorsal edge does not slope at all, the upper 
posterior corner is subrectangular, the anterior indentation 
and shallow groove are almost entirely obsolete, and the 
surface, when highly magnified, appears radiated with 
extremely delicate lineoles. 

The animal of this species was first examined by Poli, 
who, recognising its remarkable peculiarities, constituted for 
it his genus Loripes. He described and figured it as having 
but one fistulose and wrinkled siphon; a cylindrical, sub- 
ulate, and very long foot, resembling a strap, and club- 
shaped at the extremity; the mantle, open in front, fur- 
nished with two orifices, its margin crenulated ; no labial 
palps; the adductor muscles large and strong; the general 
colour white, ovaries milky, liver greenish. 


60 LUCINIDA. 


Although generally known, this cannot be regarded as 
one of our common species, perfect pairs, especially with 
the contained animal, being of comparatively rare occur- 
rence; single valves are often thrown on shore at various 
spots where there are extensive sands, chiefly on our 
southern coasts, as at Ryde and Ramsgate (S. H.), and 
Studland, near Poole (EK. F.). It ranges in depth from 
shallow water to eighty fathoms (M‘Andrew). Among its 
localities may be mentioned Guernsey (S. H.); Little- 
hampton and Selsea Bill, in Sussex (Strickland) ; South- 
ampton (Jeffreys) ; Torbay, Falmouth (Mont. and Jeff. 
cab.) ; Scarborough (Bean); Scalloway (Jeffreys); Zet- 
land (M‘Andrew); Bantry Bay in fifteen fathoms, and off 
Baltimore Harbour (M‘Andrew). 

The name of this species finds its way erroneously into 
many local catalogues, owing to dead and worn yalves of 
young Lucina borealis being mistaken for it. It ranges 
southward to the Mediterranean, where it is extremely 
abundant. 


L. rerrucinosa, Forbes. 


Minute, usually covered with a ferruginous coating, beneath 
which the surface is smooth ; devoid of any fold. Only one denticle 
in either valve : no oblique cartilage groove on the hinge-margin. 


Plate XXXIV., fig. 1 (magnified). 


Kellia ferruginosa, Forsxs, Report of the Brit. Assoc. 1843, p: 192: 

Artemis 2 » JEFFREYS, Ann. Nat. Hist. vol. xix. p. 313. 

Clausina » JEFFREYS, Ann. Nat. Hist. vol. xx. p. 18. 
BS abyssicola, JEFFREYS (not Forbes), Ann. Nat. Hist. vol. xx. p. 18. 
5 Croulinensis, JEFFREYS, Ann. Nat. Hist. yol. xx. p. 19. 


The closely-adherent thick ferrugimous coating which 
envelopes and conceals alike sculpture and outline, by 


LUCINA. 61 


rendering its description and determination a task of 
more than ordinary difficulty, has led to the separation of 
this shell into three species, a division which the close 
examination of a long suite of examples (including the 
types of the whole) compels us to regard as unneces- 
sary. 

The shape is more or less obliquely orbicular subcordi- 
form, and is usually, but not invariably, longer than broad. 
The valves, which are thin and fragile, vary much in 
profundity, but are always more or less swollen at the um- 
bones, become, if anything, rather more compressed behind 
than in front, and diminish rapidly in convexity towards the 
ventral margin: this latter is greatly arcuated anteriorly 
and obliquely, and rather suddenly ascends in a straighter 
line on the posterior side of the shell. The surface, when 
cleared of the ferruginous earth, which is often disposed in 
concentric waves, is quite smooth, and, in fine and recent 
examples, even moderately glossy white and semitranspa- 
rent, but is more usually met with dull, opaque, and partly 
eroded. The sides are nearly equal: the front one is ob- 
tusely and rather broadly rounded at its extremity; the 
hinder is bluntly angulated below. The posterior dorsal 
edge is greatly the more elevated, and runs uninterrupted- 
ly with a more or less arcuated sweep to the lower margin; 
the front dorsal edge is very short and little sloping; it 
bends inwards under the beaks, which are acute and in- 
clined. The umbones, which lean greatly forward, are 
prominent, occasionally projecting very considerably. There 
are no dorsal impressions, but the hinder area is perhaps a 
little flattened. There is neither fold nor umbonal ridge, 
and the ligament is not prominent, but is semi-internal, the 
hinge-margin being slightly excavated for its reception. 


The interior is glossy, and either white or occasionally 


62 LUCINIDA. 


stained, somewhat concentrically in aged examples, with 
purplish liver-colour. The dentition is quite rudimentary : 
there is only a tubercular denticle in each valve, that of 
the right being somewhat conical, that of the left being 
often a callous sublaminar inward projection of the front 
hinge-margin. There are no lateral lamine ; the ligament 
has hitherto been taken for them. 

There exists a more elongated variety, in which, from 
the shape, the hinder dorsal edge is almost rectilinear, and 
rather shorter than usual, and the front one less retuse ; 
the front extremity is more regularly rounded, and the 
hinder angulation more central. 

So small is this curious little shell, that an individual 
measuring the sixth of an inch in diameter, may be re- 
garded as of large dimensions. It has hitherto been solely 
procured on our coasts from northern stations, having been 
dredged in thirty fathoms by Mr. M‘Andrew in the Sound 
of Skye, and by Mr. Jeffreys, at Croulin Island, which 
lies between Skye and the mainland of Ross-shire, towards 
Applecross, and in Loch Fyne, in mud, at from twenty 
to a hundred fathoms (M‘Andrew). The species was first 
obtained by Captain Graves and Lieutenant Spratt from 
Crete and the Morea, where it inhabits very deep water. 


SPURIOUS. 
L. oreicutaris, Montagu. 


Venus orbicularis, Mont. Test. Brit. Suppl. p. 42, pl. 29. f. 7. — Turr. Conch. 
Diction. p. 241. 

Cyprinad 4, Turt. Dithyra Brit. p. 138.—Brit. Marine Conch. p. 83. 

Cytherea 4, Firm. Brit. Anim. p. 446. 

2 Lucina squamosa, LAMARCK, Anim. s. Vert. (ed. Desh.) yol. yi. p. 228. 


Montagu described this exquisitely sculptured shell from the 
single valve of an immature specimen ; we have most carefully 


LUCINA. * 63 


traced out the series, and drawn up the following description 
from the adult, in which a second lateral lamina is developed, the 
lunule is no longer minute, and the peculiar projecting angle of 
the margin above the front lateral tooth becomes occasionally ob- 
solete. The shape is suborbicular, but varies in its proportions of 
length and breadth ; the texture is strong, opaque, and of a pure 
white externally, but frequently tinged with yellow in the inte- 
rior, where there is never the slightest appearance (as there ordi- 
narily is in tigerina) of crimson stains. The valves, which are 
not very inequilateral, are rather ventricose, the chief convexity 
being at the subumbonal region ; there is no division of surface 
caused by any partial flattening of the lateral areas. The entire 
exterior is covered with very numerous radiating costellee, which 
are finest and most closely set in the middle, but become coarser 
rather less approximate and more divergent at the sides, where 
they are more manifestly bifurcated. This divergence is most 
evident near the hinder dorsal surface. Both the costelle and 
their interstices are decussated by very delicate concentric slight- 
ly raised striulee, which do not form regular sublunate scales on 
the former, but simply traverse them in the most crowded man- 
ner ; there are occasionally, however, some granular projections 
near the front extremity. The ventral margin is much arcuated, 
swelling the more in front, and rising the more behind, so as not 
unfrequently to give an obliquity of outline to the shell. The 
umbones, which incline very considerably forward, do not project 
very greatly above the dorsal margin. The declination of the latter 
is very trifling ; the front part, which is short and more or less in- 
curved, terminates at the end of the sunken cordiform lunule, at 
which point it makes a more or less marked angulation with the 
upper and straighter part of the anterior side. The hinder 
dorsal edge, which is much the more elevated and more or less 
arcuated, is ordinarily, but not invariably, subangulated, yet 
somewhat indistinctly, at its termination; the upper part of 
the posterior margin is also generally the straighter. Both ex- 
tremities are rather broad, and tolerably, but not symmetrically, 
rounded ; that of the hinder side, which is rather the longer, is 
the more obtusely so. There is no umbonal ridge: the beaks are 
very acute; the ligament is sunken and partially concealed. 
The inner margin is all but entire ; the hinge-margin of the right 


64 LUCINIDA. 


valve is furnished, besides having primary teeth, with a strong 
and not very distant lateral lamina in front, and a smaller less 
distinct and more remote one behind, both of which fit into cor- 
responding receptacles in the left valve. The front muscular im- 
pression is extremely long, and runs almost parallel to the per- 
fectly simple palleal scar. The diameter of rather a large exam- 
ple was seven-eighths of an inch. 

A West Indian shell, introduced by Montagu as found on the 
shore near Dunbar by Mr. Laskey. The Lu. imbricatula of Adams 
(Jamaica Shells) is very closely allied, but quite distinct, and 
differs in having a coarser decussation of sublunate scale-like pro- 
tuberances upon its ribs, which latter become smaller, and not at all 
divergent, but bent contrarwise, near the hinder termination. 


L. tieerina, Linnzus. 


Venus tigerina, LINN. Syst. Nat. ed. 12, p. 1134.—PuitTeEney, Hutchins, Hist. 
Dorset, p. 34.—Monr. Test. Brit. p. 119, pl. 4, f. 1.—Linn. 
Trans. vol. viii. p. 86, pl. 2, f. 5, (badly). — Dorset Catalog. 
p- 35, pl. 1, f. 14.—Turr. Conch. Diction. p. 240.—CHEmn. 
Conch. Cab. vol. vii. pl. 37, f. 390, 391. 

Lucina tigerina, Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 319, (not vars. )— 
Brit. Marine Conch. p. 76.— Drsu. Elem. Conch. pl. 16, 
f. 4, 5.—-HANL. Recent Shells, p. 78. 

Cytherea tigerina, Turt. Dithyra Brit. p. 164, pl. 10, £ 12—F.Lem. Brit. Anim. 

p. 445. 
Encyclopédie Méthodique, Vers. pl. 277, f. 4. 


A West Indian shell, introduced by Dr. Pulteney as taken at 
Weymouth, Studland, and Poole. 


DIPLODONTA, Bronn. 


Shell equivalve, more or less suborbicular, inequi- 
lateral, nearly smooth, or marked by lines of growth. 
Hinge composed of two primary teeth (one of which is 
bifid) in each valve; no lateral teeth. Ligament external. 
No lunule. Muscular scars nearly equal, ovate; pallial 
impression single. 

Animal shaped as the shell; mantle open in front, 


DIPLODONTA. 65 


simple at the edges ; siphons wanting (?); branchial lamellee 
on each side of the body not united into one; labial palps 
developed, triangular ; foot lanceolate. 

This genus was established by Bronn for some fossil 
shells from the tertiaries of Italy, including the Venus 
Jupinus of Brocchi. Mr. Gray considers it identical with 
the genus Mysia of Leach’s manuscripts, but Bronn, in 
1831, was the first to define clearly and restrict the species 
of this very natural group, and Mysia was not published 
with a definition until 1833. Our British example of it 
has been bandied from Tellina to Lucina and back again, 
finding a brief resting-place in Psammobia on the way, 
without having really very intimate affinity with any of 
them. With the Tellinide it certainly has no relations ; 
with Lucina we associate it provisionally, for, as will be 
seen presently, the account of its animal, now first made 
known by Mr. Clark, presents anomalies not reconcilable 
with the usual features of the tribe: so peculiar, indeed, 
that we would earnestly call the attention of malacologists 
to a minute examination of this curious mollusk. Possibly 
it should be considered a member of the next tribe. 

Several species inhabit the Mediterranean, and some 
extinct forms are found in the tertiary beds of the same 
region. Mr. Hanley has a Diplodonta from the West 
Indies, which seems exactly the British species. Philippi 
describes one from Mazatlan (D. obliqua), and Dunker two 
(circularis and Grunert) from Western Africa, 


VON ile K 


66 LUCINID&. 


D. rorunpata, Montagu. 


Plate XXXV. fig. 6, and (Animal) Plate M. fig. 7. 


Tellina undata, PULTENEY, in Hutchins’ Hist. Dorset, p. 30. 
»  rotundata, Mont. Test. Brit. p. 71, pl. 2, f. 3. — Linn. Trans. vol. viii. 
p. 56. — Dorset Catalog. p. 30, pl. 5, f. 8. — Turr. Conch. 
Diction. p. 176.—Woop, General Conch. p. 187.— Ditiw. 
Recent Shells, vol. i. p. 99.—Index Testaceolog. pl. 4,f. 77. 
Lucina rotundata, Turr. Dithyra Brit. p. 114, pl. 7, f. 3. —Brit. Marine Conch. 
p. 73. — Brown, Illust. Conch. G. B. p. 98, pl. 40, ££ 11.— 
Hant. Recent Shells, vol. i. p. 76. 
»  lactea2 Dusu. Encycl. Méthod. Vers, vol. ii. p. 374. 
Psammobia rotundata, FLEM. Brit. Anim. p. 438. 
Diplodonta dilatata, Puttipr1, Moll. Sicil. vol. i. p. 31, pl. 4, f. 7. 
9 rotundata, PHILIPPI, Moll. Sicil. vol. ii. p. 24. 
Loripes x Cuv. Régne Animal (ed. Croch.), pl. 103, f. 4. 
Venus fragilis, (Fossiz), Nyst and West, Bull. Brux. vi. p. 401, pl. 3, f. 11. 


The shape is suborbicular, with a tendency to square- 
ness, which latter is chiefly effected by the straightness and 
ordinary absence of declination of the hinder dorsal margin. 
The valves, which are decidedly inequilateral, moderately 
capacious, and often ventricose, are rather more swollen 
behind than in front, the chief swell being, however, sub- 
central: they are rather glossy, not quite opaque, tolerably 
firm in texture, and both externally and internally of an 
uniform white. The surface, from being more or less dis- 
tinctly marked with lines of growth, is not quite smooth, 
but is perfectly free from strie, grooves, or lamelle, and is 
not radiatingly subdivided (as in certain analogous shells), 
by any marked elevation or depression of the lateral areas. 
The anterior side, which is considerably the smaller, is 
attenuated both above and below; its dorsal edge, which is 
nearly rectilinear or subretuse near the beaks, and then 
very slightly convex, sloping rapidly downwards, and form- 
ing an obscure and almost central subangulation with the 


DIPLODONTA. 67 


ascending ventral; this latter is not symmetrically arcu- 
ated, but in the adult rises principally and obliquely in front, 
is not very convex beneath the beaks, and curves out chiefly 
towards its posterior end. The hinder side is much the 
broader, its upper corner is more or less distinctly angu- 
lated, and its lower rounded off; the posterior margin is 
usually more or less curved, but varies much in that respect, 
and the upper or dorsal margin is straight, produced, and 
not at all sloping. The umbones are moderately swollen, 
obliquely inclined, and not particularly prominent; the 
beaks, which are small and inflected, are neither preceded by 
a lunule, nor any peculiar flatness of the dorsal area. The 
ligament, which, though rather small and much projecting, 
is distinct, and occasionally of a golden yellow, is not en- 
vironed by any excavation. The internal edge of the 
ventral margin is acute, entire, and not particularly flex- 
uous. There are no lateral teeth, but two rather small 
primary ones in each valve; of which the bifid is posterior 
in the right one, and anterior in the left, where the simple 
tooth is narrow and very oblique. The muscular impres- 
sions are large, of rather a produced shape, and nearly 
equal magnitude; the pallial impression is broad and 
shining. 

The largest example we have ever seen, procured by Mr. 
Alder from the Cornish fishermen, measures exactly one 
inch in length, and eleven lines in breadth at the widest 
part. Such dimensions are nearly unparalleled, the ordi- 
dary diameter being only five-eighths of an inch. 

We have never seen the animal, but during the course 
of the summer of 1848 it was met with by Mr. Clark, who 
communicates the following account of it: — ‘“ Animal 
lentiform, moderately thick ; mantle plain, somewhat closed 
posteriorly and anteriorly, but with a large opening for the 


68 LUCINID&. 


foot in the centre of the ventral range ; no siphonal process 
is to be found; not even an orifice, except the pedal one, 
could be detected. The branchial must of course be sup- 
plied from the large aperture of the foot. The body is very 
small, pale-brown ; the liver is suborbicular, granulose, and 
black-brown ; the rectum runs through the liver. There 
are two subquadrangular branchiz, and two palpi, on each 
side the body ; the former are finely pectinated, and smooth 
on the under-surface ; the palpi are moderately long, sub- 
triangular, pointed, and striated on one side; both are of 
a good brown colour. The foot is clear white, moderately 
long, flattish, and completely lanceolate laterally, and at 
the point.” 

This is by no means a common British shell, and it is 
confined to the southern shores, ranging up the Irish sea as 
far as Anglesea. It inhabits sand. As localities, we may 
enumerate, Poole in Dorset, where it was observed by 
Montagu; Exmouth (Clark); Fowey, in Cornwall (Alder) ; 
Falmouth (Montagu, Cocks). Plymouth, dredged dead 
in twenty fathoms; Penzance in twelve fathoms ; Anglesea 
in the same depth of water, and off Lundy Island in from 
seven to twenty-five fathoms (McAndrew and E. F). 
Tenby (Lyons). On the Irish coast it occurs at Youghal 
(R. Ball), and Bantry Bay (Jeffreys). 

It ranges to the Mediterranean. As a fossil it occurs in 
both red and coralline crags, and was one of the mollusks 
which retired to southern latitudes during the glacial epoch, 
and afterwards returned. . 


KELLIAD. 


Axruouen there appears to be a limit to the dimension 
which each species of Mollusk is capable of attaining in the 
course of its growth, the several species of a genus do not 
usually exhibit uniformity of limitation, and not unfre- 
quently we find a very minute and a comparatively gigantic 
shell in the same group. In the family before us, how- 
ever, limitation of size to very small dimensions seems to be 
characteristic of all its members, and thus we are presented 
with a tribe of minute shells. 

Minuteness of size is often accompanied with eccentricity 
of variation in specific character, consequently in such a 
tribe as this the relative value of characters is not easy to 
ascertain, and the distribution of the species into genera a 
difficult and critical operation ; the more so, as it is no 
easy task to observe correctly the soft parts of such small 
mollusks, whilst the difficulty is imcreased by the scar- 
city of many of them in the living state. Indeed, until 
very lately, we had little, if any, account of the animals 
of the tribe before us, at least in an accessible form,— 
yet many years ago the inhabitants of four out of the six 
genera we have adopted in this work had been carefully 
examined and delineated by our friend Mr. Clark. To 
him and to Mr. Alder we owe all our knowledge of them, 
having ourselves examined the animal of Ke/lia only. 
From their manuscripts and some very recently published 


70 KELLIADA. 


notes and figures of M. Deshayes, and M. Mittre, we are 
enabled to present the details which will be found in the 
descriptions of the several species. 

The family of Kelliade is an assemblage of minute and 
mostly fragile bivalves, presenting but few variations of 
colour and sculpture. They are free, equivalve, often very 
inequilateral shells, closed or gaping in front. The liga- 
ment varies in position, but is commonly cardinal and in- 
ternal: the dentition is still more variable, cardinal and 
lateral teeth being present or absent according to the genus 
or species; sometimes both kinds are entirely wanting. 
The internal surface always presents an entire pallial im- 
pression and roundish muscular scars. 

The animals, so far as known, present characters of great 
singularity. Unless in Galeomma, an abnormal form at 
best, we find them distinguished by the remarkable fea- 
ture of having only one siphonal opening, and that the anal 
one, which is sometimes sessile, sometimes produced into a 
tube, whilst in most, possibly in all instances, the mantle is 
folded anteriorly into a canal or tube, which appears to be 
subservient to branchial purposes. The degree of union of 
the margins of the mantle is very variable. All have a 
grooved foot, provided with a byssiferous organ, and capa- 
ble of being used as a creeping disk. The branchial leaflets 
appear to be always separate, and the labial palps de- 
veloped. 

There would seem to be a considerable affinity between 
the Kelliade and the Arcade and Mytilide. This we see 
indicated in the variations of siphonal arrangement and the 
peculiar foot of the animals, whilst the shell of Galeomma 
reminds us of some Arks, and that of Montacuta substriata 
of Crenella. On the other hand, there are distinct relations 
to the Lucinide and Cycladide. 


MONTACUTA. viel 


MONTACUTA. Turron. 


Shell small, thin, equivalve, mequilateral, transversely 
oblong, or obliquely oval, surface smooth, or concentrically 
striated, or rarely radiatingly furrowed. Beaks inflected. 
Inner margins smooth. Hinge-margin with a trigonal in- 
cision, and cartilage pit, and a pair of diverging laminar 
teeth in one or both valves. Ligament internal. Mus- 
cular scars suborbicular, pallial impression simple. 

Animal oblong, its mantle freely open in front, with sim- 
ple margins, not furnished with siphonal tubes posteriorly ; 
a single siphonal orifice (anal) or none (?). Foot very 
large, strong, and broad, furnished with a byssal groove. 

The composition of this genus is still unsatisfactory, and 
it is very possible that when the animals of the several 
species shall be better known, a division of the group will 
become necessary. Montacuta substriata is possibly the 
type of a distinct genus, but in the present state of our 
knowledge we prefer keeping the species known as Monta- 
cute together, with the exception of MZ. purpurea. Re- 
cluz has united them with the Kellie, to which, indeed, 
they are very nearly allied. They are all minute and in- 
conspicuous bivalves, possessed of considerable powers of 
locomotion, yet also in the habit of mooring themselves 
firmly by means of a byssus. Their generic appellation 
was given in honour of Montagu, a name deeply reverenced 
by every British malacologist and deserving of some more 
conspicuous testimonial. 

The genus dates its genealogy from the epoch of the 
coralline crag in which our M. substriata and another 
species have been found fossil. 


{2 KELLIADE. 


M. rerrucinosa, Montagu. 


Elongated, smooth, moderately inequilateral. 


Plate XVIII. figs. 5, 5a, and 5 b, (as ferruginea). 


Mya ferruginosa, Mont. Test. Brit. Suppl. pp. 22, 166, pl. 26, f. 2. — Dorset 
Catalog. p. 28. — Turr. Conch. Diction. p. 102. — Woop, 
General Conch. p. 100.—Ditiw. Recent Shells, vol. i. p. 46. 
—Index Testaceol. pl. 2, Mya, f. 19. 
Montacuta ferruginosa, Turt. Dithyra Brit. p. 60.—F.em. Brit. Anim. p. 465. 
—Brit. Marine Conch. p. 52, f. 16.— Hanu, Recent 
Shells, p. 40. 
Tellimya elliptica, Brown, Ill. Conch. G. B. p. 106, pl. 42, f. 19. 
Erycina ferruginosa, Reciuz, Reyue Zool. Cuy. 1844, p. 332. 
Montacuta oblonga (Young), Turr. Dithyra Brit. p. 61, pl. 11, f. 11, 12.— 
Fem. Brit. Anim. p. 465.—Brit. Mar. Conch. p. 52.— 
Maceiiivray, Moll. Aberd. p. 302. 
Tellimya glabra (Var.), Brown, Ill. Conch. G. B. p. 107, pl. 42, f. 20, 21. 
Montacuta glabra, Maceiuiy. Moll. Aberd. p. 303.— Brite Marine Conch. 
p. 245. 


Although to be ranked among our smaller shells, the J/. 
Jerruginosa is by far the largest of the published species of 
this genus, which at the present time is very limited in the 
number of recorded members. The shape, which is not a 
little variable, ranges from simply oval to oblong-elliptical, 
the breadth being occasionally less than, but more fre- 


quently exceeding, half the length. It is decidedly inequi- 


g 
lateral, although not pre-eminently so for the genus, the 
hinder side being usually about half as large again as the 
anterior one. Its valves are slightly ventricose, glossy, and 
either substriated concentrically, or almost smooth; they 
are the former when taken (which is rarely the case) in per- 
fect condition, and containing their animal inhabitant, but 
the majority of cabinet specimens consist of single valves, 
which from previous attrition have become glabrous. The 
texture is thin, dull, fragile, but scarcely subdiaphanous, 


and of a pure white, but the surface is often concealed by 


MONTACUTA. (as: 


a thick coating of rust-coloured earth, from which cireum- 
stance the shell has derived its specific epithet. The ven- 
tral edge is but slightly convex, but curves upward at both 
extremities. The hinder side is produced ; its termination 
is usually well rounded, and a little tapering, but occasion- 
ally is subangulated above ; its dorsal edge (except in the 
elongated typical variety, where all the edges are compa- 
ratively rectilinear) is more or less convex, or even arched 
towards its termination, but straightish or even subretuse 
near the umbones; its declination is extremely trifling. 
The shorter anterior side exhibits a considerable difference 
in its aspect, being occasionally much abbreviated and 
rounded, and rather broad at its extremity, at other times 
slightly more elongated, and from the greater declination 
of the dorsal edge is narrowed and subangulated at its 
lower extremity. The beaks are small, acute, and directly 
inflected, not leaning to either side; they are distinct, but 
by no means prominent. The inside is white, the margin 
plain and acute, with often a slight vestige of a subcentral 
retusion. The hinge-margin, which is interrupted by a 
trigonal incision beneath the beaks, is furnished with an 
erect narrow simple and almost vertical tooth behind the 
notch, and a more oblique and rather less immediately 
approximate acute conical denticle before it, which latter 
projects downward and inwards, and forms apparently the 
terminal wall to an appressed and anterior cartilage-pit. 

In the right valve, where the apical perforation for the 
ligament is most evident, the posterior tooth is less de- 
veloped, hardly amounting in some individuals to more 
than an elevation of the cardinal edge. 

There are two most distinct forms of this shell; the 
rarer (which is that figured by Montagu, who, however, 
possessed both varieties, and regarded them as specifically 


VOL, IT. L 


74 KELLIAD®. 


identical) is elongated, with its margins straightish, its 
hinder extremity a little subangulated above, and its front 
one subangulated below. The other variety is less pro- 
duced, its margins more arcuated, and rounded at both ex- 
tremities. Intermediate specimens possessing the angula- 
tion of the former variety, with the abbreviated shape and 
arcuated basal margin of the latter, or the general features 
of the latter variety with the elongated shape and anterior 
subangulation of the former one, unite inseparably these 
two forms, 

The largest example we have seen measures three-eighths 
of an inch in length ; the majority of specimens do not ex- 
ceed five-sixteenths of an inch from side to side. 

‘“¢The animal of this species,” Mr. Alder writes to inform 
us, ‘“‘agrees with the other MWontacute, in having the foot 
exserted at the larger end of the shell, and presenting no 
apparent tubes. There appears to be only one posterior 
aperture.” 

This is a scarce shell, though widely distributed. The 
larger variety is in most instances sublittoral in its habits, 
the other ranging to deep water; South Devon (Jeffreys) ; 
Dartmouth in seven fathoms (M‘Andrew and E. F.); 
Tenby (S. H.); Scarborough (Bean) ; Cullercoats (Alder); 
Lamlash Bay in Arran (Alder); Inverary (Barlee); He- 
brides, Zetland, and Murray Firth (M‘Andrew); St. An- 
drews (Knapp); Frith of Forth (EH. F.); Belton Sands 
near Dunbar (Laskey). Cork Harbour (Humphreys) ; 
Youghal (Jeffreys) ; Birterbuy (Barlee) ; ‘“‘ Dublin coast, 
whence only I have yet seen specimens” (W. Thompson). 
Cape Clear in thirty fathoms (M‘Andrew). 

No foreign author notices this species as an inhabitant of 
other seas than ours. 


qn 


MONTACUTA. 7 


M. siventara, Montagu. 


Abbreviated, devoid of radiating elevated lines; front side 
excessively short, bluntly biangulated. 


Plate XVIII. figs. 6 and 6 a. 


Mya bidentata, Mont. Test. Brit. p. 44.—Linn. Trans. vol. viii. p. 41.—Turr. 
Conch. Diction. p, 102.—Woop, General Conch. p. 99.— 
Ditiw. Recent Shells, p. 45. 
Montacuta bidentata, Turt. Dithyra Brit. p. 60.—F.Lem. Brit. Anim. p. 465.— 
Macertutv. Moll. Aberd. p. 302, — Brit. Marine Conch. 
p- 52. f. 58 (badly).—AtpEr, Cat. Northumb. and 
Durham Moll. p. 95. 
Petricola of Gray, Annals of Philos. 1825.— Hanu. Recent Shells, 
p. 54. 
Erycina a5 Rectivz, Rey. Zool. 1844, p. 331. 
Tellimya as Brown, Ill. Conch. G. B. p. 107, pl. 44, f. 8, 9. 


In outline this species approaches the subrhombic oval, 
the dorsal margin running in some degree parallel with the 
ventral. The valves are excessively imequilateral, their 
convexity is but moderate, their substance very thin and 
fragile, but not at all translucent, and their surface nearly 
smooth, or at most but striolated, and equally devoid of 
lustre as of colour. The ventral margin varies from simply 
convex to subareuated ; and the hinder dorsal edge, which 
is elongated, and at first straight or scarcely convex and 
hardly declining, forms by its junction with it a well- 
rounded and rather broad posterior extremity. The front 
side, which is infinitely the smaller, varies, however, in its 
proportion to the hinder, being at times only one-fifth as 
large as the latter, whilst, in certain specimens, it occupies 
more than one-fourth the entire length of the shell. The 
front dorsal edge is rather retuse than otherwise, and by its 
very abrupt descent narrows the anterior extremity, which 
by the ordinary absence of arcuation in the front margin 
appears very bluntly biangulated. The beaks are acute, 


76 KELLIAD&. 


inflected, oblique, and one of them tolerably prominent. 
The interior is white and glossy, and the margin simple. 
The hinge consists, in the left valve, of an apical laminar 
tooth on each side of the beak, each diverging widely 
from the other, and separated by a wide triangular cavity. 
The hinder tooth is by far the larger, and both are absent 
in the edentulous right valve, which, however, presents 
much resemblance to the other, from the margins themselves 
on either side of the still broader triangular cavity bemg 
elevated so as to resemble laminz, but not like the teeth 
of the other valve, distinctly divided from the rest of the 
dorsal margin, by an intervening sulcus. Professor Lovén 
has detected a rudimentary ossicle, which appears to Mr. 
Alder, who has likewise observed it in British examples, 
a mere calcification of the lower part of the ligament. It 
is so easily detached that very few cabinet specimens ever 
exhibit it. The length of the shell is half as large again 
as the breadth, and at the very most is but a quarter of an 
inch, but rarely, indeed, attains to much more than half 
that measurement. 

A sketch, communicated by Mr. Alder, represents the 
animal extending its large and broad foot from the longer 
extremity, but presenting no traces of siphonal tubes. 
This is a well-diffused species, but never a very common 
one, indeed, pairs are very scarce, and even single valves, 
except locally, are not plentiful. It is generally found 
burrowing in very thick valves of dead oysters. It is 
taken at Cullercoats, near Newcastle (Alder) ; Scarborough 
(Bean); Weymouth (Jeffreys) ; Saleomb Bay (Mont.) ; 
Liverpool (M‘Andrew). In Wales, at Tenby (Lyons and 
S. H.); Oxwich Bay, near Swansea (Jeffreys). Belfast 
Bay extremely rare, and Dublin Bay (W. Thompson) ; 
Portmarnock, Bantry Bay, and Cork Harbour (Hum- 


MONTACUTA. Ue 


phreys), are among its Irish localities. In Scotland, in 
many of the lochs and other localities among the Hebrides 
(Jeffreys and Barlee) ; Lamlash Bay, in Arran (Alder). 

The bedentata of Gould, does not exactly coincide (in 
description, at least,) with our British species. 


M. sussrriara, Montagu. 


Very oblique ; with divergent elevated lines upon the um- 
bones. 


Plate XVIII. figs. 8 and 8 a, and (Animal) Plate O. fig. 2. 


Mya substriata, Monv. Test. Brit. Suppl. p. 25.—Turr. Conch. Diction. p. 103. 
— Woop, General Conch. p. 102. — Dittw. Recent Shells, 
vol. i. p. 47. 
Montacuta substriata, Turt. Dithyra Brit. p. 59, pl. 11, f. 9, 10. — FiEm. Brit. 
Anim. p. 465.— Mace. Moll. Aberd. p. 303.— Brit. 
Marine Conch. p. 51. — AtpsErR, Cat. Northumb. and 
Durham Moll. p. 96. 
Erycina substriata, Reciuz. Rey. Zool. 1844, p. 330. 
Tellimya substriata, Brown, Ill. Conch. G. B. p. 107, pl. 40, f. 23. 
2 Sphenia costulata, Maceituty. Moll. Aberd. p. 301.-— Brit. Marine Conch. 
p- 245 (copied). — Brown, Ill. Conch. G. B. p. 133 
(copied). 

This little bivalve, which derives additional interest from 
its peculiar habitat, is remarkably oblique in outline, very 
thin, fragile, semi-transparent, extremely inequilateral, and 
of a more or less oval shape. The valves are not ventricose, 
but are moderately convex, the swell being generally dif- 
fused over the upper portion, and diminishing gradually 
and equally towards either extremity ; when fresh, they 
are covered with a glossy yellowish (or colourless) skin, 
beneath which the surface is pale or whitish. The exterior 
is marked with radiating subdivergent elevated lines, which 
are rather distant, not readily perceptible, and most ap- 


parent upon the middle area: there is no other sculpture 


78 KELLIADA. 


whatsoever. The anterior side, which is greatly the longer, 
is ample, and is rounded almost symmetrically both above 
and below, its dorsal margin being arcuated, except near 
the beaks, and ordinarily but little declining. The ventral 
edge is slightly contracted near the middle, but swells out 
in front, and ascends with rather a straightish inclination 
on the posterior side. This latter, which is excessively 
short, is narrowed not only by the rise of the ventral mar- 
gin, but also by the decided slope of the hinder dorsal edge, 
which latter rarely displays much, if any, convexity, so 
that although the posterior tip is curved, the hinder ex- 
tremity is not distinctly and symmetrically rounded. The 
umbones are very prominent ; the beaks acute and inflected. 
There is neither an umbonal ridge, nor any dorsal depres- 
sions. The front laminar tooth is large and distinct in 
each valve, in the right it is triangular: the hinder one is 
very obscure, and only rudimentary, being rather the den- 
ticular termination of the supporting plate of the large carti- 
lage, than a veritable tooth. This shell is very diminutive, 
being but an eighth of an inch in length, and only a tenth 
of an inch in breadth. 

“¢ Animal sub-oval, thick for its size, with an oblique out- 
line, the longitudinal measure being greater than the trans- 
verse. Body and mantle of the palest yellow, liver dark- 
green. Foot hyaline. The mantle has the margin simple, 
and is largely open ventrally, for the passage of the foot, 
which has a byssal groove at its heel, from which strong 
filaments issue, and attach it to its usual habitat, the 
spines of Spatangus purpureus ; all the eleven observed 
specimens were thus attached, and could not well be re- 
moved by force without injuring the animal or shell. They 
were cut off by scissors, and, on being placed in a watch- 
glass of sea-water, immediately put forth their large foot, 


MONTACUTA. 79 


far exceeding any measure of the shell in length, and which 
is muscular, strong, flat, raised in the centre throughout its 
length, being bevelled to a fine awl-like edge, but its base 
is very broad, and it tapers to a very rounded termination, 
not shewing a trace of a lanceolate point. Its locomotive 
powers would appear to be incompatible with its apparently 
fixed habitat, if we did not infer that it can detach itself to 
change place 


a power we have observed in other byssal 
bivalves. When the animal marches the foot is greatly 
extended, and in this case the rounded termination was 
instantly fixed to the side of the watch-glass filled with 
sea-water, in which it was placed. By the muscle of 
the foot it drew itself forwards, ‘ cterwmque, iterumque,’ 
and this mancuvre was executed with such rapidity that 
the watch-glass was crossed ina minute. In its passage, 
the creature, by a twist of its foot, several times turned 
the shell from one side to the other. Not a trace of sipho- 
nal processes, or even a simple orifice could be observed 
in the mantle at either end. When opened for examina- 
tion the large foot was the most prominent object, and, 
with a powerful lens, the byssal groove was distinctly 
visible. Though a pectinated lamina was seen, it was 
impossible, with the appliances used, to develop the form, 
or detect the presence of palpi in an animal not one-eighth 
of an inch in diameter.”-—Crarx, MSS. 

‘* Mr. Howse’s observations on the animal of this species 
agree with ours on MM. bidentata, as to the shape and 
position of the foot, and apparent absence of siphons.”— 
ALDER. 

Whenever we have met with this curious and scarce 
shell alive, it has been attached by its byssus to Spatangus 
purpureus. Though rare, it has a wide distribution. 


Among corallines in deep water on the Devonshire coast 


80 KELLIADZ. 


(Montagu); Exmouth (Clark); Penzance in twenty fa- 
thoms (M‘Andrew and E.F.); Scarborough (Bean). 
‘Taken abundantly by Mr. R. Howse on the spines of Spa- 
tangus purpureus from sixty fathoms water, fifty miles off 
the coast of Durham.” (Alder.) To the west of Manor- 
beer, in Pembrokeshire (Lyons); Tenby (Jeffreys) ; Isle 
of Man in twenty-five fathoms (E. F.); from fifty to one 
hundred and forty fathoms off the Mull of Galloway 
(Beechey); Loch Alsh (Barlee); Copenhaw-head, off 
Skye, in forty fathoms; Balta Sound or Unst, in from five 
to ten fathoms and in ninety fathoms, thirty miles from 
land off Zetland (M‘Andrew) ; Lerwick (Jeffreys) ; Aber- 
deenshire (Macgillivray). Entrance of Belfast Bay, in 
twenty-five fathoms (Thompson); Arran, west of Ireland 
(Barlee) ; Bantry Bay (Jeffreys). Lovén records this 
shell as ranging to Finmark on the Scandinavian seas ; it is 
not known south of Britain. 


TURTONIA. HANLEY. 


Shell minute, fragile, equivalve, very inequilateral, 
closed at both ends, transversely oblong ; surface concentri- 
cally striated or nearly smooth. Ligament external ; hinge 
with two adjacent teeth in front, the anterior one laminar. 
Pallial sinus simple. 

Animal with the mantle widely open anteriorly, a single 
very slender siphonal tube at the shorter end, and an 
ample and strong foot angulated at its posterior base pro- 
ceeding from the longer. 

The features of the curious and very minute bivalve for 
which this genus has been founded are so peculiar, that its 
claim to become the type of a separate group cannot be 
called in question. Resembling a Montacuta in external 


TURTONIA. 81 


aspect, the shell is removed at once from that genus by the 
structure of its ligament, whilst the produced anal siphon 
equally distinguishes the animal. Professor Loven, in his 
“Index Molluscorum Scandinavie,” has placed the Tur- 
tonia minuta, with a query, in Cyamium of Philippi, a 
genus founded for a curious antarctic shell, but where it 
cannot remain, since the latter has an internal ligament. 
The genus is dedicated to Dr. Turton, a clever but 
eccentric conchologist, who, by his energy and scholarship, 
gave a great impulse to the study of our native shells. 
‘His collections are fortunately mainly preserved in the 
magnificent cabinet of our valued friend and correspondent, 
Mr. Gwyn Jeffreys. A close examination of them has 
shewn that Turton was not always to be relied upon in 
his published statements, and that a severe and critical 
judgment must be applied to his labours in conchology. 


T. minuta, O. Fabricius. 


Plate XVIII. fig. 7 and 7 a, and (Animal) plate O. fig. 1. 


Venus minuta, O. Fasr. Fauna Grenl. p. 412. 

Mya purpurea, Monv. Test. Brit. Suppl. p. 21.—Torr. Conch. Diction. p. 102. 
—Woop, General Conch. p. 100. — Dittw. Recent Shells, 
vol. i. p. 46. 

Montacuta 2 purpurea, HANt. in Brit. Marine Conch. p. 25, f. 14. 

Erycina purpurea, Reciuz. Rey. Zool. 1844, p. 329. 

Lesea minuta, MouuER, Ind. Moll. Greenl. p. 20. 

Saxicava purpurea, Brown, Ul. Conch. G. B. p. 103 (not figures). 

Cyamium 2 minutum, Lovén, Ind, Moll. Scandinavie, p. 42. 

Turtonia minuta, ALDER, Cat. Northumb. and Durham Moll. p. 95. 


This minute shell, which, although known to Montagu, 
escaped the observation of Turton, is of an oval and very 
slightly sub-cordate shape, thin, semitransparent, very in- 
equilateral, slightly glossy, almost smooth, and of a pur- 
plish brown tint, which becomes deeper coloured poste- 

VOL, II. M 


82 KELLIADA. 


riorly, the front being so pale as, in some specimens, al- 
most to be devoid of colouring matter ; the beaks are dark 
purple. The valves are moderately convex, and rounded 
at both ends, the termination of the posterior side,—which 
is much produced,—more obtusely and broadly so ; the ex- 
tremity of the anterior side,—which is both narrow and 
small, at most occupying one-fourth of the length of the 
shell, and a very much smaller proportion of its area,—sim- 
ply and regularly so. The ventral margin is subarcuated, 
and both dorsal lines are decidedly convex, the front one 
declines strongly, the hinder one scarcely slopes at all. 
The umbones appear oblique, and when viewed in front 
are decidedly prominent, they being raised on that side con- 
siderably above the dorsal line. The beaks themselves are 
blunt, and there is no defined Junule in front of them. The 
internal colouring resembles the external, the margin is 
plain, and the pallial impression, as far as can be ascer- 
tained, is simple and not sinuated. The cardinal edge is 
very narrow, only jutting out just at the shorter side, to 
which portion of it the dentition is confined. The extreme 
minuteness of the teeth almost baffles one’s eyesight, even 
when aided by the most powerful lens, and from the lesser 
size of our British examples, the dentition does not appear 
so clearly developed as in the northern exotic ones.* 

We are unable to perceive any lateral teeth, although 
there is a very slight elevation of the hinge-margin at the 


* Loyén’s description of the hinge stands thus :—“ Cardo valve dextre fossa 
lunulari parum profunda, dente lunulari subtrigono, valido, fossa cardinali an- 
gusta, profunda, subtrigona, dente cardinali feré sub medio umbone sito, lunulari 
paullum minore, rotundato ; valve sinistree dente lunulari minuto, antrorsum 
obliquo, foss&i lunulari magna, trigona, dente cardinali valido, fossa cardinali 
magna, satis profunda; dentes laterales parum prominuli, longitudinales: im- 
pressio muscularis antica duplex, superior minuta, inferior ovalis, verticalis, 
posterior ovalis, superne emarginata ; impressio palliaris yix discernenda integra 
videtur.”—IJndex Moll. Scand. p. 43. 


TURTONIA. 83 


extremity of the ligament in each valve, which may pos- 
sibly be regarded as such by some individuals. There 
appear to be two primary teeth in each valve, but so close- 
ly adjacent, as almost to resemble a single complicated one. 
In the right valve, the lunular or foremost one is strong 
and subtriangular, the other, which lies under the middle 
of the umbo, is somewhat smaller; in the left valve the 
central tooth is the larger, and is conic and erect, the 
lunular one being the less conspicuous, inclining forwards, 
and, as well as in the right valve, somewhat laminar. The 
ligament is not really internal, yet is not visible until the 
valves are opened, lying as it does between the hinder dor- 
sal edges without projecting externally. The length of 
this minute shell rarely exceeds the twelfth of an inch, and 
its breadth is but a trifle more than half that measure- 
ment. 

All we know of the animal is contained in the generic 
character, due to the observations of Mr. Alder. It in- 
habits pools and crevices of rocks between tide-marks, 
usually high up, often im company with Kellia rubra. 
Adhering to corallinz from the rocks of the little islet of 
Herm near Guernsey (S. H.); at Scarborough it is com- 
mon in the roots of the Chondrus crispus (Bean); it is 
likewise captured in Northumberland (Alder) ; Whitesand 
Bay in South Devon (Jeff. cab.) ; Exmouth (Clark) ; Fal- 
mouth (Jeffreys) ; abundant among the roots of Corallina 
officinalis and Lichina, near high water-mark on slate rocks 
in the Isle of Man (EK. F.). At the roots of Lichina 
pygmea, Oxwich and Langland Bays in Glamorganshire 
(Jeff.) ; Tenby (Lyons). 

In Ireland it is found in Cork harbour (Humphreys) ; 
Portmarnock, Belfast (Jeff. cab.) ; and is indeed ‘ abund- 


ant on the north-east coast, in the stomachs of Mullets ” 


84 KELLIADE. 


(Thompson, Ann. Nat. H. vol. v. p. 14). Coast of Wex- 
ford and Waterford (E. F.); Dublin Bay (Alder); Bir- 
terbuy Bay and Arran Isles on west coast (Barlee.) 

In Scotland it is taken on Tarbert Island (Jeffreys) ; 
Oban (Barlee) ; Orkneys (Thomas). 

The Turtonia minuta was first observed by that most 
acute naturalist, Otho Fabricius, who found it in Green- 
land. It is enumerated among Scandinavian shells by 
Loven, and Recluz states that it is very common on the 
west coast of France near Cherbourg. 


KELLIA. Turton. 


Shell thin, equivalve, subequilateral, suborbicular, tumid 
or compressed, closed, smooth, or concentrically striated. 
Beaks incurved, small ; inner margin smooth. Hinge com- 
posed of one or two primary teeth in either, and a lateral 
one in both valves. Ligament internal or submarginal ; in 
some species (Poronta) placed on a cartilage bed, formed 
of the thickened hinge margins of each valve, in others 
(Keira), interrupting the hmge margin. Muscular scars 
suborbicular, pallial sinus entire. 

Animal suborbicular, its mantle much closed, furnished 
posteriorly with a single, very short, siphonal (anal) tube, 
and anteriorly prolonged into a canal or hyaline tube, of 
considerable dimensions, the margins of which are either 
united, so that a separate orifice is formed, or open, so as 
to be continuous with the pedal slit. Foot ligulate, fur- 
nished with a byssal groove. Branchial leaflets free ; late- 
ral palps triangular. 

This genus was formed by Turton, for the reception of 
the Cardium rubrum and Mya suborbicularis of Montagu. 
Subsequent researches have shewn, that the group so pro- 


KEELE. 85 


posed is a natural one, and Philippi, unacquainted with 
Turton’s yenus, framed his Bornia for the same assem- 
blage of species. When two naturalists, working apart, 
constitute generic groups of equal limitation, there is a 
strong presumption in favour of the naturalness of the sec- 
tions proposed. 

Recently, however, M. Recluz has proposed the generic 
separation of the two shells mentioned, and regards them 
as the types of different genera. Convinced that the Poron 
of Adanson, somewhat indistinctly described and figured 
by that celebrated naturalist, is a near ally of the Kellia 
rubra (a conclusion to which he has been Jed by an exami- 
nation of the Senegal shells in the collection of M. Petit) ; 
he constitutes a genus Poronta for these shells, founding it 
chiefly in minute peculiarities of the hinge.* These differ- 
ences seem, he remarks, in a tone of censure, to have 
escaped Fleming and Macgillivray, who have not, however, 
in their descriptions, committed the very unscientific mis- 
take of uniting an animal with two separated siphons to a 
shell presenting an entire pallial impression. We are inclined 
ourselves to regard such minute variations of hinge and 
ligament, as of little value in this family—a view we take, 
in common with two most sound authorities, Lovén and 
Alder. The latter malacologist, has, however, discovered 
a feature in the animal of Kellia rubra, so peculiar, when 

* The generic character given by M. Recluz, runs as follows :—‘‘ Testa ovata 
seu subrotunda, regularis, transversalis, cequivalyis, ineequilatera, clausa. Apices 
minuti, anticé recurvati. Lunula areaque nulla. Cardo dentibus cardinalibus 
duobus in utraque valyula, apicali minima ante auctam (?), antica majori apicalem 
approximata, transversali, concava, ad marginem superam inflexa et in valvula 
dextra inserta; fossula interposita, elongata, oblique valde transversali, sub 
dente laterali decurrente, ligamentum magnum, cartilagineum, unicum ferente ; 
dente laterali unica, postica, remota, in valvula sinistra triangularia, in dextra 
inserta. Impressiones musculares ovales, zequales. Sinus palliaris nullus, 


“ Animal fere ignotum, pallio postice bilobo ; siphonibus duobus, disjunctis ; 
pede plano, acuto.””—Recluz, Revue Zoologique, June, 1843. 


86 KELLIADA. 


compared with that presented by Kellia suborbicularis, viz., 
the open anterior tube of the former, as contrasted with the 
closed one in the latter, that we were almost inclined to 
adopt Poronia in a new sense. But in one of the lately- 
published numbers of the “ Mollusques d’Algerie ” there 
is a beautiful figure of the animal of Hrycina Geoffroy, 
an undoubted Kellia as to its shell, presenting the very 
conformation observed by Mr. Alder in the rubra, whilst 
on the other hand, a figure of the Bornia seminulum of 
Philippi, identical specifically with the rubra, represents 
the anterior process as a true tube; in this respect agree- 
ing with a drawing and description of the animal of rubra, 
communicated to us by Mr. Clark. These facts induce us 
to conclude, that the peculiar conformation of the hyalime 
anterior process, whether tube or canal, is probably an in- 
dividual, and possibly a sexual difference. At any rate, in 
the present state of the case, it cannot be received as 
generic. We need scarcely say, that the animal of the 
Poron, as quoted by Recluz from Adanson, does not in the 
least agree with that of any of our Kellie. Chironia of 
Deshayes and Cycladina of Cantraine appear to be syno- 
nymous groups. 

The Kellie are small, but elegant, bivalves, living 
usually in crevices of rocks, or shells, or sea-weeds, spimning 
a byssus, or lying free. They bear a striking external 
resemblance to the fresh water Cyclades. Some live along 
the coast line, others in the depths of the ocean. They 
have been included in the heterogeneous genus Lrycina, 
founded by Lamarck, for a strange melange of Tellina, 
Diplodonta, Astaries and Kellia, but proposed recently by 
M. Recluz to be restricted to an assemblage including 
Kellie proper and Montacute. The name, however, with 
all the confusion which attends it, had far better be 


KELLIA. 87 


dropped altogether. That of Aellia was given by Turton, 
in honor of his friend and instructor, Mr. O’Kelly of Dub- 
lin, a gentleman who, we are happy to say, is still among 
us, enjoying the pleasures of natural-history research in 
his native land. There are about a dozen species of Kellia 
known (including Poronia), scattered through the seas of 
all parts of the globe. Kellie occur also as tertiary fossils, 
and have been enumerated, but without sufficient grounds, 


among the carboniferous limestone shells of Ireland. 


K. sunorsicutaris, Montagu. 


Pure white, more or less ventricose, two primary teeth in one of 
the valves. 


Plate XVIII. figs. 9, and 9 a, 9 b., and (animal) Plate O. fig. 4. 


Mya suborbicularis, Mont. Test. Brit. p. 39, and 564, — Linn. Trans, vol. viii. 
p. 41.—Ditiw. Recent Shells, vol. 1. p. 55. 

Tellina suborbicularis, Turr. Conch. Diction. p. 179. 

Kellia suborbicularis, Turt. Dithyra Brit. p. 56, pl. 11, f. 5, 6.— FieEm. Brit. 
Anim. p. 430.—Macerty. Moll. Aberd. p. 276.—Brit. 
Marine Conch. p. 51.—A.peEr, Cat. Northumb. and Dur- 
ham Moll. p. 93.—Index Testaceolog. pl. 3, f. 37.— 
Hant. Recent Shells, vol. i. p. 43, pl. 3, f- 37. 

Bornia inflata, Puitiert, Moll. Sicil. vol. i. p. 14, and vol. ii. p. 11. 

Tellimya suborbicularis, BRowN, Illust. Conch. G. B. p. 106, pl. 42, f. 14, 15. 


An examination of a large number of specimens, so 
closely united by exact links, that their specific identity is 
irrefragable, demonstrates, that without the distortion, by 
which in other ithodomous genera (Petricola, Venerupis, 
Saxicava, &c.), the shape is so strangely transmuted, the 
outline of this Aelia may vary from subrhombic, with 
the distance from the anterior to the posterior extremity 
greatly exceeding that from the beaks to the opposite mar- 
gin, to triangularly orbicular, with the breadth surpassing 


88 KELLIAD A. 


the length, which latter outline is necessarily accompanied 
by a greater declination of the dorsal edges. 

The ordinary shape, then, is subrhombic, with the angles 
softened down; the shell is ventricose or inflated (if much 
produced, it is comparatively compressed), very thin and 
fragile, moderately inequilateral, and of a transparent white, 
under a very delicate glossy yellowish epidermis, which, 
in certain specimens, faintly reflects prismatic colours. 
The surface is almost smooth, and not distinguished by any 
other sculpture than more or less developed concentric 
striule ; it is, moreover, not polished, but faintly shining. 
The ventral and hinder dorsal edges are more or less sub- 
parallel, although inclining a little towards each other ; 
the former is convex at the extremities (where it ascends 
nearly equally on either side), but a little straightened in 
the middle ; the latter barely convex and (except in the 
abbreviated variety) scarcely slopmg. The hinder side, 
which occupies about two-thirds of the shell, is broad and 
very bluntly subbiangulated at its extremity, the posterior 
edge not being arcuated, but, at most, convex. The front 
extremity, which is rather the narrower one, is almost 
symmetrically rounded in the more produced forms, and 
bluntly rounded in those which are less elongated; the 
lower corner is invariably rounded, the upper less habitu- 
ally so; the front dorsal edge is straightish near the um- 
bones, then more or less convex, and, except in the abbre- 
viated form, declines but very moderately. The umbones 
are rather prominent and incline slightly forward; the 
beaks are small, very acute and hardly lean to either 
side. There is no lunule, nor any inflection of the dorsal 
surface. The interior is white, with a large elongated 
somewhat triangular rather oblique brownish-yellow liga- 


ment, situated close under the beaks on the posterior side, 


KELLIA. 89 


(interrupting the hinge margin, and causing, when removed, 
an apparent cavity in it); behind it, in either valve, stands 
a subtrigonal, and rather remote, lateral lamina. In the 
right valve, the short but rather broad anterior hinge-mar- 
gin, which is subvertically truncated just beneath the 
beaks, is furnished with a single erect somewhat re- 
curved primary tooth, immediately under the apex of the 
shell: this tooth leans a little forward, and, as well as its 
opposing ones, is not bifid. In the left valve are two ad- 
jacent primary teeth ; the more central, having either a per- 
pendicular or posterior inclination, is separated by a slight 
triangular incision of the hinge-margin from the anterior 
one, which latter (usually the less elevated, often appearing 
a simple upeurving of the notched hinge-margin) leans 
slightly forward.* 


* From the small size and extreme fragility of the teeth, and the liability of 
portions of the cartilage to be mistaken for them, it is not impossible that the 
Tellimya lactea and tenuis of Brown, are only individuals of this variable species. 
At least such appears to be the general opinion of conchologists, none of whom 
have been fortunate enough to procure examples agreeing with the descriptions, 
which, upon close scrutiny, haye not proved to be individuals of the A. suborbi- 


cularis. 


Tellimya lactea, Brown, Ill. Conch. G. B. p. 106, pl. 42, f. 10, 11. 


“ Nearly orbicular, inflated, thin, pellucid, and glossy white; one valve with 
two teeth locking into a triangular void in the opposite valve, with transverse 
laminz on each side ; left valye with a single recurved cardinal tooth, and a cen- 
tral triangular laminated tooth, and one remote lateral tooth only. About a 
quarter of an inch in diameter. Found on the Devonshire coast by Dr. Leach.” 

Captain Brown, who still retains his original impression of its distinctness, 
informs us that his drawing was taken in 1819, at the British Museum, from a 
specimen in Dr, Leach’s collection. 


Tellimya tenuis, Brown, Ul. Conch. G. B. p. 106, pl. 42, f. 12, 13. 


* Orbicular, smooth, glossy, snow-white, with fine irregular concentric striz, 
much inflated ; umbones rather produced, and much turned to one side; left 
valve destitute of cardinal teeth, and provided with two large lateral teeth ; right 
valve with two incurved cardinal teeth and a lateral one ; inside white, and when 
viewed through a strong lens, has a shagreen-like appearance. Diameter three- 
eighths of aninch. Found at Newbigging, Northumberland, by W. C. Trevelyan, 
Esq., and is in his cabinet at Wallington.” 


VOL. Il. N 


90 KELLIADZ. 


The hinge sometimes appears different, from there 
being a very minute almost linear denticle, immediately 
above the single tooth of the right valve, which, in 
some specimens, becomes more developed, inducing 
the idea of there being two primary teeth in each valve ; 
and all these teeth frequently curve towards the beaks. 
The internal surface, when slightly magnified, appears 


a little punctulate, but does not exhibit any pallial 
sinus. 


Specimens are usually about five-twelfths of an inch long, 
and very nearly a third of an inch broad, but the propor- 
tions are very variable ; we have seen none exceeding half 
an inch in length. 

The fullest published account of the animal of this pretty 
and Cyclas-like shell is contained in Mr. Alder’s valuable 
catalogue of the Mollusca of Northumberland and Durham. 
From this description, extensive manuscript notes commu- 
nicated by Mr. Clark, and our own observations, we have 
drawn up the following summary of its features. It is 
white and translucent; the mantle is closed, except at 
three places, viz., in front or ventrally, where there is an 
orifice for the passage of a narrow, long, slender, ligulate 
foot ; anteriorly, where it is produced into a hyaline tube, 
undivided within, very broad, and capable of extension to 
a length equalling the breadth of the shell; posteriorly, 
where there is a single, very short tube or siphon, seldom 
protruded beyond the shell. The margins of all these 
orifices are plain, but there is a fringe of very minute, 
short, distant, tentacular processes on the mantle, just 
within the edge of the shell. The foot is furnished with a 
byssal groove. The branchial leaflets are symmetrical and 
subtriangular, the labial palps short, subtriangular, and un- 


equal. When the animal is confined, as it often is, in the 


KELLIA. 91 


erevice of a rock or the cavity of a shell, its locomotion is 
almost limited to a half-circular turn on one of its sides ; but 
when free, it is capable of considerable change of place, 
aided by its strap-shaped foot, crawling forwards, back- 
wards, or sideways, indifferently,—“ especially ” as Mr. Al- 
der observes, “ when it is ascending a perpendicular surface, 
which it frequently does, for the purpose of suspending 
itself by its byssus. The byssal aperture is about half way 
up the foot, on the posterior surface, from which the animal 
produces a very delicate thread, and suspends itself freely 
by a single, almost inconspicuous fibre, strengthened by a 
double attachment at the top.” Mr. Clark informs us, 
that though Kellia suborbicularis appears to be oviparous, 
the point admits of doubt, for he has observed a speci- 
men containing a completely-formed testaceous young 
one. 

This species ranges from low-water mark (though not, 
strictly speaking, ever a littoral shell) to sixty fathoms, 
abounding most in about fifteen or twenty. It lives in 
crevices of stones and shells, and Laminaria-roots, or gre- 
gariously in the mud, filling cavities of dead bivalves, such 
as Tapes virginea, and sometimes, though less frequently, 
quite free. It is generally distributed around our shores, 
ranging from Guernsey (S. H.) to Zetland; so generally, 
indeed, that though not reckoned one of our commonest 
species, a few localities only, illustrative of range in depth, 
may be mentioned :—Portland in fifteen fathoms; Pen- 
zance in twenty ; Anglesey in twenty-five ; Isle of Man in 
twelve to twenty-five (M‘Andrew and E. F.) ; Northum- 
berland, at the roots of seaweeds, &c. (Alder); Zetlands, 
at low water, and in five, ten, twenty, and sixty fathoms 
(M‘Andrew) all round the west coast. In three to ten 
fathoms in Clew, Clifden, and Killery bays (W. Thompson, 


92 KELLIADZ®. 


R. Ball, and E. F). Ranging to Bergen, in Norway, north- 
wards, and to the Mediterranean, southwards. It is a crag 
fossil. 


K. niripa, Turton. 


Minute, white ; not more than one primary tooth in either valve. 
Plate XXXVI. fig. 3, 4. 


Lepton nitidum, Tur. Dithyra Brit. p. 63.—F em. Brit. Anim. p. 429.—Brit. 
Marine Conch. p. 49. — Maceinuiy. Moll. Aberd. p. 278.— 
Brown, Ill. Conch. G. B. p. 111. 

The dentition of this shell, which has a primary tooth 
in each valve, by no means agreeing with the characters 
assigned to the hinge of Lepton by Turton (at is, more- 
over, closed at the sides, and not a “little open”), we 
are compelled to remove it from that genus to the pre- 
sent, of which we regard it as a somewhat aberrant 
species. 

From its rare occurrence, and its very insufficient de- 
scription in the pages of the ‘‘ Conchylia Dithyra Britan- 
nica,” it has generally been conjectured to be the young of 
the Lepton squamosum, to the fry of which, except in 
shape, it bears but little resemblance, the characteristic 
punctures being clearly manifest in all stages of that 
species: it is far more liable to be confounded with the 
young of K. suborbicularis, from which, however, its more 
compressed shape and solitary apical tooth, suffice to dis- 
tinguish it. Its white, thin, and subdiaphanous valves, 
which, when fresh, are covered with a shining ochraceous 
epidermis (variable in depth of tint, being occasionally 
very pale), reflecting a little the prismatic colours, are 
much depressed, excepting upon the umbonal region : the 


compression is nearly equal on both sides. The shape is 


KELLIA. 93 


nearly elliptical, but rather abbreviated, the surface devoid 
of all sculpture, and the ventral margin but little convex 
in the middle, though arcuated at both extremities. The 
sides are very nearly equal, and the dorsal edges, which 
decline so slightly as almost to be parallel with the lower 
margin, are nearly equally elevated, and each a little 
convex. Both the front and hinder outlines are arcu- 
ated and not angular, and the two extremities are nearly 
equally broad. That which is rather the shorter, and 
which, reasoning from analogy, we have termed the ante- 
rior, is rather the more obtuse; the scarcely longer pos- 
terior side is, if anything, rather the more attenuated 
above, from the more oblique uninterrupted arcuated 
sweep of the dorsal margin. The beaks are distinct, but 
not prominent, and scarcely lean to either side, yet if at 
all to the shorter one. The hinge of both valves displays 
a single narrow erect and obliquely slanting apical tooth 
(which seems rather more conical in the right one), on 
either side of which extends a distinct lateral lamina 
(these are almost double in the left valve, but the upper 
or outward set are very obscure), the front one shorter 
and immediately adjacent, the hinder less approximate 
and more produced. These lamina, which are in advance 
of the hinge-margin, lean over it in the right valve, and, 
especially in front, curl, as it were, outward. 

The extreme length of the largest specimens is scarcely 
the sixth of an inch, and their breadth is rather less. 

The original locality of this species was Torbay, where a 
few examples were procured from corallines by Dr. Turton. 
Mr. Lyons (of Tenby) acquired his specimens from the 
coral-sand of Bantry Bay, and a single broken valve (ap- 
parently belonging to this species) was taken by Mr. 
Jeffreys near the Island of Skye. Professor Macgillivray 


94 KELLIADA. 


states, that he has taken it in shell-sand from the beach 
which lies between the mouths of the Dee and the Don. 
The figure of Lepton fabagella in Conrad’s “ American 
Marine Conchology,” is not unlike (pl. 11, f. 3) this spe- 
cies in general appearance, but the hinge exhibits no 


primary tooth. 


K. (eoronta) rupra, Montagu. 


Minute, tinged with red or green. 


Plate XXXVI. fig. 5, 6, 7 (as Poronia rubra), and (Animal) Plate O. fig. 3. 


Cardium rubrum, Mont. (not ReEve) Test. Brit. p. 83.—Linn. Trans. vol. yiii. 
p. 66.—Woop, General Conch. p. 213.— Ditiw. Recent 
Shells, vol. i. p. 131. 
Tellina rubra, Turt. Conch. Diction. p. 168. 
Cellia rubra, TurvT. Dithyra Brit. pp. 57, 258, pl. 11, f£ 7, 8. — Fem. Brit. 
Anim. p. 430.— Brit. Marine Conch. p. 51. — Macernt. Moll. 
Aberd. p. 277.—HANL. Recent Shells, p. 43, suppl. pl. 9, f. 49. 
Bornia seminulum, Putt. Moll. Sicil. vol. i. p. 14, pl. 1, f. 16, and vol. ii. p. 11. 
—Desu. Exp. Scien. Algérie, Moll. pl. 43, f. 8 to 11, and 
pl. 43 A, f. 6, 8 (anatomy). 
Poronia rubra, Reciuz, Revue Cuy. Zool. 1843, p. 175.—H Ant. in Brit. Mar. 
Conch. p. xxy.—CueEnv, Ill. Conch. Poronia, p. 3. 
Lasea rubra, Brown, Ill. Conch. G. B. p. 93, pl. 36, f. 17, 18. 


This minute shell is strong for its size, more or less 
ventricose, semi-transparent, devoid of lustre, of a rich 
purplish red, or of various intensities and shades of yellow 
stained with purplish rose at the longer extremity, and 
mottled or banded with the same near the umbones; 
more rarely of a dirty greenish hue or almost destitute 
of colour. The form is somewhat variable, but generally 
is oval-orbicular, longer than broad, and always more or 
less oblique; more rarely the breadth and length are 
equal, and the shape consequently approaching to orbi- 
cular. The surface, although not perfectly smooth, is 
devoid of any visible sculpture, and does not possess any 


KELLIA. 95 


umbonal fold or ridge; the beaks are touching, prominent; 
but very blunt, and do not apparently lean to either 
side; the umbones themselves are very wide. The sides 
are unequal; the posterior occupying at least three-fifths 
of the entire Jength. Both sides are rounded at their 
extremities; the hinder, which is very slightly tapering, 
the more regularly; the front, which is likewise the 
broader, the more obtusely so. The ventral edge is simply 
and distinctly arcuated ; the front dorsal margin is short, 
straightish, and but moderately sloping; the hinder dorsal 
edge scarcely declines at all, but is straight near the beaks, 
and then more or less arcuated. There is no lunule, nor 
any trace of one. The colour of the interior, which often 
exhibits a resinous gloss, is usually deeper than that of the 
exterior; the hinge-margin is almost invariably stained 
dark purplish red, and the margin is perfectly entire and 
closed all round. ‘The dentition of the right valve consists 
of a very small sharp central tooth and a rather larger 
widely diverging one just behind the apex; the anterior 
hinge-margin is extraordinarily thickened in both valves, 
forming a broad but shallow bed for the elongated carti- 
lage that runs along the inner edge of it, which slopes 
inwards. The other valve contains a rather approximate, 
small anterior lateral tooth, and an oblique tooth-like 
laminar elevation of the hinge-margin (which is not unfre- 
quently surmounted near its commencement with a minute 
apical denticle) just behind the apices. Specimens at all 
worn, or when examined with a lens of low power, only 
exhibit a broad hinge-margin with a wide triangular 
excavation just beneath the apices of the shell. 

The average length is about the seventh of an inch, and 
the breadth is nearly a quarter less. 


Minute as this shell is, its animal has not escaped 


96 KELLIADZ. 


examination; Mr. Alder, Mr. Clark, and M. Deshayes 
have independently examined its structure with care. It 
is of a white colour, and has the mantle closed posteriorly, 
gaping in front, where the broad-based, strap-shaped, 
stout foot is protruded. Its margins appear to be quite 
plain and free from tentacles. Anteriorly they are pro- 
duced so as to form a hyaline, tube-like canal, differing 
from that of Kellia suborbicularis, as was first observed by 
Mr. Alder, in being open below. Into this anterior 
siphon-like organ the foot is sometimes pushed. The 
anal aperture is not prolonged into a tube. According 
to Mr. Clark, this animal is viviparous, and in the month 
of July he found its ovarium full of perfectly-formed, 
minute testaceous young. This is quite a new fact in 
‘the economy of these bivalves, and very interesting as 
reminding us of a similar habit in the Cylas, to which 
the sub-genus Poronia (as well as Kellia proper) bears a 
striking external resemblance. 

This is a strictly littoral species, living gregariously in 
the crevices of rocks, among congregations of barnacles 
and the roots of Corallina, Lichina, and Fucus, between 
tide-marks. It is not so generally diffused as it is locally 
plentiful. Among localities may be enumerated Torquay 
(S. H.); Burrow Island (S. H.); Herm near Guernsey 
(S. H.); Exmouth (Clark); Dartmouth, where some 
specimens occurred in the crevices of a mass of stone 
dredged from seven fathoms,—a very exceptional locality 
(M‘Andrew and E. F.); Whitesand Bay and Falmouth 
(Jeffreys) ; Glamorganshire, Tenby, and St. David's (Jef 
freys); Isle of Man, very abundant all round the coast 
wherever there is rock (EK. F.); Scarborough (Bean) ; 
Northumberland, near Whitley (Alder); and at the roots 


of Lichina pygmea on the rocks below Bamborough Castle 


LEPTON. 97 


(Thompson) ; Inner and Outer Hebrides (Barlee); Ork- 
neys (Thomas) ; Aberdeenshire (Macgillivray). ‘‘ On each 
side the coast of Ireland. Found among J/ytili growing 
on the rocks at the Skerries off Portrush, and about the 
roots of Alge growing between tide-marks, Belfast Bay 
and coast of Clare” (W. Thompson). 

It appears to be generally distributed through the North 
and South Atlantic, ranging into the Mediterranean. The 
Kellia rubra of North America, judging from the ex- 
pression of Gould (Invert. Massachuss. p. 60, f. 33), seems 
to differ from this species, although, perchance, as that 
admirable describer observes, not essentially so. The 
hinge of Mediterranean examples, received from Dr. Phil- 
lippi, is much more developed, and the teeth longer and 


more manifest than in our British shells. 


LEPTON. Turron. 


Shell equivalve, suborbicular, subequilateral, compressed, 
surface shagreened or smooth, gaping slightly at the sides ; 
beaks acute; margin plain. Hinge composed of a pair of 
teeth-like lamina on each side of a triangular central 
excision in one valve; a primary apical tooth in front of a 
subtriangular excision of the hinge-margin, and flanked on 
each side by a sublateral lamina on the other. Pallial 
impression simple. 

Animal compressed, mantle freely open in front, its 
margin extending considerably beyond the shell, and 
bearing superiorly a fringe of filaments, one of which is 
much larger than the rest. A short siphonal tube, with 
single aperture at the larger end of the shell. Foot thick 
and tapering, keeled and disked, furnished with a byssal 
groove. Branchial leaflets two on each side, and separate. 


VOL, II. oO 


98 KELLIADA. 


This very curious genus has close affinities with Kellia, 
but is sufficiently distinct in both shell and animal. As 
yet, besides the British species, only one other form of it 
has been described, viz., the Lepton fabagella of Conrad, 
from the shores of the United States; there are, however, 
doubts respecting the true position of the latter. 


L. sauamosum, Montagu. 


Not minute, flat, contracted above, retuse at the ventral edge ; 
central tooth very small. 


Plate XXXVI. fig. 8, 9, and (Animal) Plate O. fig. 6. 


Solen squamosus, Monv. Test. Brit. p. 565.— Linn. Trans. vol. viii. p. 48. — 
Turr. Conch. Diction. p. 164.—Woop, General Conch. p. 
140.—Dimxw. Recent Shells, vol. i. p. 70. 
Lepton squamosum, TurtT. Dithyra Brit. p. 62, pl. 6, f. 1, 2, 3.— Fie. Brit. 
Anim. p. 429.—Brit. Marine Conch. p. 49.—Browy, IIl. 
Conch. G. B. p. 111, pl. 40, f.7, (very badly).—SowErsy, 
Conch. Manual, f. 62. 
Lutraria squamosa, Gray, Annals of Philosoph. 1825.— Hant. Recent Shells, 
vol. i. p. 28, suppl. pl. 9, f. 47. 
Lepton squammeua, CHENU, Traité Elem. p. 47, f. 148. 

In whatever point of view we regard the Lepton squamo- 
sum, whether as almost the sole representative of a rare 
and (geographically) limited genus, or for the extreme 
scarcity of its appearance in a perfect state, or as dis- 
tinguished by a most delicate and almost unique style 
of sculpture, it will hardly fail to excite a more than 
ordinary interest. The valves are so remarkably com- 
pressed as nearly to be flat; they are semi-pellucid, thin, 
and extremely brittle. In shape they are of a suborbi- 
cular oval, and decidedly longer than broad ; they are of 
an uniform white both within and without, are rather 
glossy when fresh, and, in addition to a few antiquated 


lines of growth, are covered with a most minute shagreen- 


vy aX 


LEPTON. ; 99 


like sculpture, the surface appearing under a lens of small 
power to be punctured all over, but under the microscope 
to be most crowdedly set with the most minute tubercles 
imaginable. The ventral margin is retuse in the middle, 
and rises with nearly equal arcuation at either extremity. 
The sides are very nearly equal, and are rounded at their 
extremities, both the front and hinder edges being well 
arcuated, and their chief swell rather below than above 
the middle ; from this point the edges incline inwards, so 
that the dorsal margin, which on the shorter side declines 
convexly and but slightly, whilst it almost rises on the 
longer and very slightly broader side, is manifestly shorter 
than the lower one. The upper portion of the extreme 
margin of the longer side is rather more oblique and 
straight than the corresponding portion of the shorter 
one; hence, the former side projects rather the more 
below, and the latter is rather the more (but not quite) 
symmetrically rounded. The beaks, which scarcely ap- 
pear above the dorsal line, are very acute, and hardly 
lean to either side. There is neither lunule nor umbonal 
ridge, and the dorsal edges do not bend inward on either 
side. 

The interior is glossy, and adorned with fine radiating 
lines; the edges are quite plain. The hinge of the right 
valve consists of two short nearly parallel teeth-like 
lamine, on either side of, and immediately adjacent. to, 
a broad triangular central excision ; of which the anterior 
set are rather the more abbreviated. The left hinge ex- 
hibits a narrow apical tooth, which curves slightly for- 
ward, behind which les a subtriangular’ excision of the 
hinge-margin, and on either side an adjacent sublateral 
lamina; of which the anterior, which is decidedly the 


shorter, and occasionally somewhat resembles an oblique 


100 KELLIADA. 


cardinal tooth, is separated from the central tooth by a 
narrow cavity. 

Few examples exceed half an inch in length, and about 
three-eighths of an inch in breadth. 

At the meeting of the British Association at Oxford, in 
1847, the following interesting particulars respecting this 
Mollusk were communicated by Mr. Alder :— 

‘“* When lately dredging in Fowey Harbour, I fortunately 
met with a living individual of this rare genus, the Lepton 
squamosum, which I have kept alive for a fortnight, and am 
thus enabled to supply some account of its characters and 
habits. The animal has proved very interesting, on account 
of its variation from the usual form of the bivalve Mollusca. 
It is of a transparent white. The mantle is very large, and, 
when fully extended, is at least one-third larger than the 
shell, passing considerably beyond it in the free part, which 
is thin and transparent, with a smooth undulating margin. 
Between this and the shell there is a fringe of filaments, 
extending completely round to the umbones, but largest 
and most conspicuous on the back. There is, however, a 
single filament, much stouter and longer than the rest, 
which, when the animal is crawling, is waved to and fro, 
like a tentacle, apparently feeling the way as it goes. The 
other filaments are comparatively motionless, floating loosely 
in the water, though capable of being thrown out or with- 
drawn, at pleasure. The mantle is open for about three- 
fourths of its circumference, being united for a short space 
before and behind: in the latter part it forms a short 
siphon, with a single aperture. The foot is very large, 
rather thick and tapering in front, with a slight nipple-like 
termination ; behind, it extends into a long pointed heel, 
with thin margins, which are divided for about half the 


length of the base, forming, in that part, a kind of dise, the 


LEPTON. 101 


edges of which can be either closed or expanded, as in the 
foot of the Nucule. As may be imagined from the size of 
the foot, it has the power of crawling about very freely, 
and sometimes it also swims inverted on the surface of the 
water in the manner of the gasteropods, the hinder part of 
the foot being then unfolded into a dise: but its favourite 
position is that of repose, suspended freely in a perpendicu- 
lar position, with the umbones downwards, by three or four 
threads, so fine, that they cannot be seen by the naked eye, 
and even with a magnifier can only be observed in certain 
positions of light. The byssal aperture appears to be about 
the centre of the foot. When the animal is withdrawn, 
the shell can be completely closed, but usually the valves 
are held a little open, and the mantles protruded beyond 
them. The siphon is at the longer end of the shell. The 
branchial leaflets are two on each side, attached to the 
inside of the mantle.” 

As long ago as June, 1835, this remarkable creature 
had been drawn and noted by Mr. Clark, at Exmouth, but 
his notes remained unpublished. _ They agree in most par- 
ticulars with those of Mr. Alder, the only essential differ- 
ence being his observation “of two very small orifices, a 
little separate from each other, above the posterior end of 
the foot.” 

This scarce shell is very rarely obtained entire, dead 
single valves being the usual condition of cabinet specimens, 
and good examples of them are not common. It inhabits 
the laminarian and coralline regions chiefly, towards the 
south and west. Montagu, its discoverer, took a solitary 
example in Salcomb bay. On the south coast of England it 
occurs,—in fifteen fathoms, West Bay of Portland, and in 
twenty-eight fathoms off Plymouth (M‘Andrew and E. F.); 
Exmouth (Clark); Torbay (Alder); most numerous at 


102 KELLIADA. 


Tenby (S. H.); in twelve fathoms, Anglesea (M‘Andrew). 
On the Scottish coast it has been taken at Oban (Barlee) 
and off Skye (Jeffreys). On the Irish Coast it was first 
taken in twenty fathoms, Cove of Cork (EH. F. and Riz 
Ball); since in Bantry Bay (M‘Andrew) ; Arran Isles 
and Birterbuy Bay (Barlee). 

Mr. M‘Andrew has dredged this curious Mollusk on the 
Atlantic Coast of Spain. 


L. convexum, Alder. 


Minute, a little swollen, not contracted above ; punctures longer 
than broad ; central tooth rather large. 


Plate XXXVI. fig. 10 (magnified), 


Lepton convexum, ALDER, Catalogue of the Mollusca of Northumberland and 
Durham, p. 93. 

‘‘ Shell rather convex, transversely ovate, white; covered 
with minute transversely oblong punctures; hinge with the 
central tooth rather large, and the lateral laminz small. 

“A single valve of a minute shell, with these characters, 
has occurred to us at Cullercoats. It is evidently a Lepton, 
and differs from the LZ. sguamoswm in being rather more 
convex, in having the punctures of the surface oblong 
instead of circular, and in the greater proportional size of 
the tooth. These seem to indicate a specific distinction ; 
but as the specimen is scarcely a line in diameter, and 
probably young, we cannot speak very confidently. The 
nucleus on the umbo is, however, so much smaller than 
that of L. syuamosum, that we conclude it never attains 
the same size.” 

Although since the publication of this interesting new 
species a live and perfect individual (delineated in our 


LEPTON. 103 


engraving), in the highest state of preservation, clothed 
with a gorgeous epidermis reflecting prismatic hues of 
garnet-red and emerald-green, has been dredged from 
Bantry Bay in Ireland by Mr. M‘Andrew, we have 
given Mr. Alder’s description verbatim, refraining from 
any additional particulars, lest, from our present limited 
state of knowledge, our details should prove incidental to 
the specimens, and not essential to the species. The con- 
tour, we may remark, is by no means go elliptical as in the 
fry of sguamosum, but abbreviated or rounded oval, not 
contracted above and dilated below, as in the preceding 
species, but of nearly equal length throughout ; the ventral 
margin is well arcuated, and no trace is exhibited of that 
basal retusion which seems constant in the adult of our 
larger Lepton. The texture is not particularly thin and 
fragile, as would probably be the case were it merely the 
fry of that species; the shoulders seem of nearly equal 
elevation, and the inclination of the broad and prominent 
umbone is (if at all) towards the longer side of the 
shell. The punctures diminish in size and number towards 
the lower edge. 

Mr. Jeffreys possesses a minute Lepton, taken at Ex- 
mouth by Mr. Clark, which in convexity and outline 
agrees very well with this shell; its punctures, however, 
seem scarcely transverse, and the extreme delicacy of its 
transparent valves deters us from an examination of the 
hinge. The exterior of it exhibits a very beautiful appear- 
ance from the commingling of the exquisitely fine radiating 
lineoles, which exist in the substance of the shell itself, 
with the incipient punctures. 


104 KELLIADA. 


GALEOMMA. Turron. 


Shell thin, transversely oval, equivalve, subequilateral, 
gaping widely in front; its surface longitudinally striated 
and decussated; beaks minute, acute; cartilage pits under 
the beaks, small; no hinge teeth; ligaments internal. 
Pallial impression simple, muscular scars unequal. 

Animal oval, mantle very large, double margined, tuber- 
culiferous ; closed in front; siphonal openings posterior, 
two. Foot long, ligulate, byssiferous, perforate, projecting 
from an anterior opening of the mantle; two pair of 
branchial leaflets ; mouth with large lips and developed 
labial palps. 

This very curious genus was first made known by Tur- 
ton in 1828. The same species was afterwards strangely 
described as a Hiatella by Costa, and an antarctic form 
was figured in one of the French voyages as a Psammobia. 
Its true systematic position has been much disputed. 
That, however, it has no affinities with the Tubicole or 
Tellinide a glance at either shell or animal will suffice, and 
it seems strange that conchologists of experience should 
ever have so placed it. Its true position is unquestionably 
about where we now introduce it, viz. as a link between 
the Kelliade and the Arcade. With the latter family its 
alliances have been clearly shewn by Mr. Clark. M. 
Mittre holds that it is closely connected with the Tridac- 
nide, and should form the type of a family parallel with 
that tribe. 


GALEOMMA. 105 


G. Turron, Sowerby. 
Plate XXXVI. fig. 11, and (Animal) Plate O. fig. 5. 


Galeomma, Turton, Zool. Journal, vol. ii. p. 361.— Ann. Nat. Hist. vol. iv. 
De g2spleosite 4. 
. Turtoni, SowERB. Zool. Journ. yol. ii. p. 361, pl. 13, f. 1. — Fie. 

Brit. Anim. p. 466.— Brit. Marine Conch. p. 33, f. 72.— 
Brown, Ill. Conch. G. B. p. 114, pl. 23, f. 15, 16.— 
SoweErBy, Genera Shells, Galeomma, f. 1, 2, 3.— Sow. 
Conch. Manual, f. 58, 59.— Lam. Anim. s. Vert. (ed. 
Desh.) vol. vi. p. 180. — Desu. Elem. Conch. pl. 11, f. 13 
to 17.—ReEEvE, Conch. System. vol. i. pl. 54, f. 1. 2, 3. — 
Pur. Moll. Sicil. vol. ii. p. 18, pl. 14, f. 4.— Hann. 
Recent Shells, p. 59, suppl. pl. 9, f. 42. — Dzsu. Exp. 
Scient. Algérie Moll. pl. 82 (anatomy), and pl. 81, f. 11 
to 15.—Mirrre, Ann. Sc. Nat. 3rd series, vol. vii. p. 169, 
pl. 5, f. 1-8. 

Miatella Polit, Cosva, Ann. Se. Nat. Ist series. vol. xv. p. 100. 

Parthenope formosa, Scaccut, Oss. Zool. p. 8, pl. 19 (ac. to Phillippi). 

For the discovery and publication of this most interest- 
ing shell, the student of nature is indebted to Dr. Turton, 
who, however he may have erred in his system of arrange- 
ment and in unnecessary subdivision of species, did as- 
suredly introduce to our notice some most important 
generic and specific forms of the testaceous Mollusca. 
This delicate shell, which was named by Mr. Sowerby in 
his honour, is of a most fragile texture, and of a pure 
semi-transparent white. Its shape is a produced oval, and 
its valves at the umbonal region are decidedly convex, but 
elsewhere a little compressed; at the most it possesses a 
slight pearly gloss, but, excepting in fine condition, is 
destitute of any lustre. Its surface is traversed from the 
beaks to the margins with most crowded irregular-looking 
elevated lines, which are extremely fine, and are continu- 
ally bifurcating ; those on the central area radiate down- 
wards, but those upon the somewhat compressed lateral 
areas diverge upwards. Most exquisitely minute and 

VOL. II, P 


106 KELLIADZ. 


wavy concentric raised striula decussate the preceding, 
but demand, in many specimens, the most searching scru- 
tiny for their detection. The entire base of the shell is 
really gaping; that is to say, when the dorsal margins 
touch throughout, the ventral edges do not touch at all. 
This hiation is contracted in the middle, and pointed at 
each extremity, the former being caused by a shallow and 
rather broad depression, which is evident near the lower 
margin, just under the beaks. These latter are minute 
and by no means prominent, but easily discernible on 
account of their acuteness. The somewhat tapering ex- 
tremities of both the sides, which are nearly equal, are 
tolerably rounded. The dorsal edge is typically recti- 
linear, and not sloping on either side, the rounding of the 
extremities being effected by the anterior and posterior 
margins ; sometimes, however, it is very slightly convex 
and a little declining on either side; the ventral is re- 
tuse in the middle, but convex towards each extremity. 
There is no distinct umbonal ridge; the interior is white, 
and the cartilage pits, which lie under the beaks in the 
narrow hinge-margin, are extremely small, and somewhat 
triangularly linear: the hinge is destitute of teeth. 

The animal of Galeomma Turtoni has been described and 
figured by M. Mittre from life, and some elaborate repre- 
sentations of it are given by M. Deshayes in his “ Mol- 
lusques d’ Algérie.” In 1835, it was met with by Mr. 
Clark at Exmouth, and ample notes and sketches taken, 
but not published. We have collated these with the ac- 
count published in the “ Annales des Sciences Naturelles,” 
for March, 1847, by M. Mittre, and thus drawn up the 
following description, never having been so fortunate as to 
have had an opportunity of examining and delineating this 
rare Mollusk in a living state. 


GALEOMMA. 107 


Animal white, thick, shaped like the shell, but larger 
than it. The mantle is greatly developed, and closed in 
front; it has a thickened, furbelowed double border, the 
outer part lining the margin of the shell, and furnished with 
a series of rounded distant tubercles, the central ones 
largest, all placed at regular distances, and of a brilliant 
white-frosted aspect. There are nine or ten on each side, 
the intervals between them furnished with a fringe of fine 
short white triangular filaments. Both observers quoted 
compare the tubercular bodies to the so-called eyes of 
Pecten. Anteriorly the mantle is open for the passage of 
a long, cylindrical, very extensile foot, furnished with a 
byssiferous organ at its base: its margins pout out beyond 
the shell in a lip-like manner. Above the mouth is a short 
tube, apparently imperforate, and furnished at its extre- 
mity with a small process, reminding us of the organ at 
the anterior end of Lepton. Posteriorly it forms two short 
tubes, an upper and small one, which is the anal one, and 
a lower and larger branchial siphon, the former with even, 
the latter with sinuated margins to its orifice. There are 
a pair of branchial leaflets on each side, and also a pair of 
labial leaflets, more coarsely pectinated than the branchial. 

Mr. Clark states that it adheres so strongly by means 
of its byssus, as, when the animal was taken, to require 
some force to detach it from the rock. “ During twenty- 
four hours,” he states, ‘‘ we kept it alive in a saucer, and 
three or four different times it spun a byssus, once de- 
taching itself and leaving the threads behind, crawling to a 
short distance and then again attaching itself. We had 
the good fortune to witness the operation. From the slit 
at the root of the foot a light green glutinous matter was 
poured out with such rapidity, that in less than five 
minutes the animal was fixed. When detached it opened 


108 KELLIADA. 


its valves, laying them on each side nearly flat, and 
marched across the saucer by means of its foot with such 
rapidity that ten could scarcely be counted: it seemed to 
be considerably assisted by the large margins of the 
mantle.” M. Mittre states that it lives on the roots and 
leaves of fuci at a depth of from three to four fathoms, 
and looks like beautiful pearls when seen beneath the water. 
He also observes that it is viviparous in the strictest sense 
of the term. : 

Mr. Alder, in a letter received whilst these sheets were 
passing through the press, urges attention to the skin cover- 
ing the shell of Galeomma. “ Phillippi,” he observes, 
‘¢ mentions it ; but I think he passes it over too slightly, as 
it appears to me to make the shell really an internal one, 
the only instance of such among bivalves (?). In Mytilus 
and Solen the horny epidermis of the shell is a continuation 
of that of the animal, but in other respects does not differ 
from the regular epidermis of shells. In Galeomma the 
covering of the shell is a combination of the true skin, and 
consists of two layers; the lower of which is slightly mus- 
cular, and under the microscope the muscles may be seen 
interlacing each other in all directions, The outer layer is 
granular, and is covered with tubercles, which possibly, 
when the animal is alive, may rise into papille. The struc- 
ture of the shell appears peculiar.” 

Phillippi, in his ‘‘ Enumeratio Molluscorum Sicilize,” 
vol. ii. p. 18, states, ‘‘ Kpidermis in hoc genere productio 
cutis manifesta ; etenim facile a testa sejungitur et pallio 
adheret.” He states that the animal was first observed 
by Scacchi. 

The specimens described are five-eighths of an inch 
in length by nearly three-eighths m breadth; they were 
taken alive by Mr. Hanley in the little islet of Herm near 


GALEOMMA, 109 


Guernsey, where they are only procurable at very low 
tides in an extremely limited space, where a few can 
occasionally be obtained by heaving over some of the 
largest stones, beneath the hollowed bases of which the 
valves are seen adhering to the rock, not in the ordinary 
closed position of bivalves, but flatly expanded, and co- 
vered with a thin white skin. Single valves in a worn 
condition are found mixed with innumerable dead Rissoe 
in the tiny bay of the islet, which is so noted for its 
minute shells ; but even in that state they are not abundant. 
Mr. Metcalfe and Mr. Barlee have found them in the same 
locality. Mr. Clark procured it at Exmouth. The ori- 
ginal locality given by Dr. Turton was the British Channel, 
from whence he obtained them by the assistance of a 
dredge. According to Mr. G. B. Sowerby, a single valve 
marked ‘‘ Ireland” was contained in the collection of 
Humphreys. It appears to be frequent in the Western 
Mediterranean. 


110 


CYCLADID.®. 


A crovur of freshwater mollusks, whose shells resemble 
those of Kellia or of Astarte, but whose soft parts present 
structures conspicuously distinguishing them from the tribes 
to which either of those genera belongs. The shells are 
more or less tumid, equilateral or equilateral, thin, as in 
our British forms, or thick, as in the foreign Cyrene, smooth 
or concentrically striated and furrowed, and covered with 
an epidermis. The hinge is furnished with cardinal and 
lateral teeth, and the ligament is external. The animals 
have plain-edged mantles, open in front; siphonal tubes 
produced, and either partially separated or completely 
united to their unfringed extremities; and a large lingui- 
form foot. They live buried in the mud of slow streams, 
lakes, ponds, ditches, and springs. Our native species are 
all ovoviviparous. They breed readily in confinement, and 
often exhibit considerable activity, ascending the sides of 
the vessel in which they are placed. 


CYCLAS. BrucGuiire. 


Shell equivalve, thin, suborbicular, more or less inflated, 
slightly imequilateral, closed, smooth or concentrically 
striated. Cardinal teeth minute (in British species), one in 
the right and two in the left valve ; lateral teeth developed. 


Ligament external, more or less conspicuous, placed on the 
fo) ) r] 


CYCLAS. 111 


larger side of the shell. Muscular and pallial impressions 
indistinct, the latter with a sinus. 

Animal suborbicular, its mantle freely open in front, and 
anteally united posteriorly, to form a produced siphon, 
divided at its extremity into two nearly equal tubes, which, 
as well as the margins of the mantle, are not fringed. Foot 
large, linguiform, very extensile. Labial palps long and 
lanceolate. 


C. rrvicona, Leach. 


Oval-globose, striated ; umbones obtuse ; dorsal area with a 
small lunular impression ; ligament manifest. 


Plate XX XVII. fig. 1, 2, and (Animal) Plate Q. fig. 1. 


Cardium nux, Da Costa, Brit. Conch. p. 189 (in part). 
Tellina cornea, var. ®. Linn. Trans. yol. viii. p. 59.—Turr. Conch. Diction. 
p- 180. 

Cardium corneum, (Thames var.) Mont. Test. Brit. p. 86. 

Cyclas cornea, DRAPARN. Moll. Ter. et Fluy. France, p. 128, pl. 10, f. 1, 2, 3.— 
Brarp, Coq. Ter. et Fluv. de Paris, p. 219, pl. 8, f. 2, 3. 

Cardium amnicum, Dorset Catalog. p. 32. 

Cyclas rivicola, LeacH, in Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 267. — 
Torr. Dithyra Brit. p. 248, pl. 11, f. 13. —F.Lem. Brit. Anim, 
p- 452.—Turt. Manual L. and F. W. Shells, p. 12, pl. 1, f. 1.— 
Jenyns, Trans. Cambridge Phil. Soc. vol. iv. p. 294. — Gray, 
Manual L. and F. W. Shells, p. 279, pl. 1. f. 1.— Brown, 
Illust. Conch. G. B. p. 93, pl. 39, f. 16,17, 18. — PrErrrErR, 
Deutsh. Land und Sussw. Mol. p. 12], pl. 5, f. 3, 4, 5.— 
Sowerby, Genera of Shells, Cyclas.—Kickx, Moll. Brabant, 
p- 86.—Desu. Encye. Méth. vol. ii. pt. 2, p. 36.—Sow. Con- 
cholog. Manual, f. 111. —Rrtve, Conch. Systematica, pl. 62. 
Han.zy, Recent Shells, vol. i. p. 89, pl. 5, f. 90. 

Encyclopédie Méthod. Vers, pl. 302, f. 5. 


This large Cyclas (for, although of no peculiar magni- 
tude as a shell, we know of no other species in its genus 
which surpasses its dimensions) is of a nearly oval form, 
and slightly, yet distinctly, inequilateral. It is moderately 
ventricose, and comparatively strong and opaque: the swell 


112 CYCLADIDA. 


is chiefly superior, and the diminution of it,on either side of 
the beaks takes place without any marked inequality, or 
any flattening of the surface adjacent to the dorsal slopes. 
The valves are regularly girt with more or less closely-dis- 
posed elevated concentric strie, which are very manifest 
below and anteriorly, but usually become obsolete upon the 
umbonal region. The colour of the glossy epidermis is 
brownish-green, with usually two or three darker zones, and 
occasionally (but rarely) some indistinct dusky linear rays 
towards the ventral margin, near which latter the surface 
almost invariably assumes a yellower cast. Both extremi- 
ties are rather broad; that of the slightly shorter anterior 
side is more rounded than the hinder termination, which 
has a tendency to biangulation, although the corners are 
generally rounded off. The ventral edge is moderately 
and equably curved; the declination of either dorsal edge 
is but trifling, and the curvature but slight. The ligament 
is distinct, and even slightly projecting at its extremity, 
and is environed and succeeded by a yellowish stain, where 
the dorsal edge is likewise somewhat flattened. The um- 
bones, which are tumid, obtuse, and usually of a paler tint 
than the prevailing ground-colour, are preceded by a nar- 
row and not profoundly impressed lunule, which is also of 
a yellowish hue; both dorsal markings are occasionally 
rendered more vivid by a not unfrequent darker stain at 
both extremities of that margin. The interior is of a 
bluish-white. 

The ordinary length of the finer specimens is ten lines 
and a half, and its breadth about two-thirds of an 
inch. 

The tubes of the animal are tinged with rose or tawny, 
and when fully protruded are nearly equal, the branchial, if 
either, being longest. The foot is large, white, and lingui- 


CYCLAS. Ma 


form; the mantle white, the labial palps long, triangular, 
and strongly striated. It is sluggish in its habits. 

The most prolific locality is the River Thames; it is 
found likewise in the New River (Baily); the Trent 
(Jenyns) ; the Lea (S.H.); the canals about Leamington, 
in Warwickshire (Thompson); streams in Yorkshire 
(Bean). In a pond at Enville, Staffordshire, a young 
specimen (Jeffreys). It has not been taken either in Scot- 
land or Ireland. On the Continent it occurs in Germany, 
France, and Belgium ; and as a fossil, is found in the Pleis- 
tocene freshwater beds of the south of England. 


C. cornea, Linnzus. 


Suborbicular, almost smooth; umbones obtuse ; ligament 
inconspicuous. 
Plate XX XVII. fig. 3, 4, 5, 6. 


Tellina cornea, LiNN. Syst. Nat. ed. 12, p. 1120; Fauna Suecica, ed. 2, p. 517. 
— Pennant, Brit. Zool. ed. 4, p. 89, pl. 49, f. 36. — Linn. 
Trans. vol. viii. p. 59.—Donov. Brit. Shells, vol. iii. pl. 96.— 
Turt. Conch. Diction. p. 179. — ScuRr6TER, Flussconchylien, 
p- 189 (partly), pl. 4, f. 4. — Diniw. Recent Shells, vol. i. 

p- 104 (chiefly). 

»  rivalis, MULLER, Verm. Terr. et Fluy. vol. ii. p. 202. 
Cardium corneum, PutTENEY, Hutchins, Hist. Dorset, p. 31. — Mont. Test. 
Brit. p. 86.—Dorset Catalog. p. 32. 
Cyclas rivalis, DRAPARN. Moll. Terr. et Fluv. France, p. 129, pl. 10, f. 4, 5 
(not well).—Brarp, Coq. T. et Fl. Paris, p. 222, pl. 8, f. 4, 5 
(badly). 

» cornea, LAM. Anim. s. Vert. (ed. Desh.) vol. vi. p. 268 (not vars.).— 
_‘Turr. Dithyra Brit. p. 248, pl. 11, f. 14.—Frem. Brit. Anim. 
p- 452.—Turt. Manual. L. and F. W. Shells, p. 13, pl. 1, f. 
2.— JENyns, Trans. Cambridge Phil. Soc. vol. iv. p. 295. — 
Gray, Manual L. and F. W. Shells, p. 280, pl. 1, f. 2.— 
Browy, Illust. Conch. G. B. p. 93, pl. 39, f. 19. — PFEIFFER, 
Deutsch. Land und Siissw. Moll. pt. 1, p. 120, pl. 5, f. 1, 2.— 
Nitsson, Moll. T. et Fl. Sueciee, p. 96.— Kickx, Moll. Bra- 
bant, p. 87. — Puinipri, Moll. Sicil. vol. ii. p. 30. — Gras, 
Moll. T. et Fl. de la France, p. 72, pl. 6, f. 2.—HaANLEy, Re- * 
cent Shells, vol. i. p. 89, Suppl. pl. 9, f. 14. 


VOL. Il. Q 


114 CYCLADIDA. 


Tellina stagnicola, Supp. Linn. Trans. vol, xiv. p. 150. 
Cyclas flavescens, Maceituty. Moll. Aberdeens. p. 246. 
»  citrina, Brown, Ill. Conch. G. B. p. 182, pl. 39, f. 37 (from type). 


The most frequent, variable, and widely-diffused of our 
freshwater bivalves is incontestably the Cyclas we are 
about to describe. The shape is ordinarily suborbicular or 
rounded-ovate, but is occasionally more produced: the 
valves are never compressed, and usually are swollen, or at 
least ventricose ; they are moderately thin, not diaphanous, 
but little shining, and with their surface, which is never 
striated in a regular manner, although there are indistinct 
concentric striule on many individuals, of an ashy-olive 
colour, or of a more or less squalid yellow, either uniform 
or stained above with the former, and below with the latter 
tint; occasionally, too, there are yellowish zones on an 
olivaceous ground, or the shell is altogether of a brownish 
hue. The diminution in convexity is nearly equal on either 
side of the umbones; there is no flattening of the lateral 
dorsal surfaces. The curve of the ventral margin is gene- 
rally a little diminished in the centre; the front dorsal 
edge is the less elevated, but the more convex and sloping ; 
the almost horizontal hinder dorsal edge merges, without 
marked angulation, into the more or less arcuated and little 
oblique posterior margin, so that both extremities appear 
more or less rounded, but that of the scarcely shorter an- 
terior side assumes, from the superior dorsal declination, a 
more attenuated form. The umbones are broad and obtuse, 
and do not ordinarily lean to either side; they are not 
preceded by any distinct lunular impression, but there is 
frequently a deceptive dusky stain of colouring matter both 
there and on the opposite side of the beaks; the ligament, 
too, is so small, narrow, and depressed, as almost to be 
totally imperceptible. 


CYCLAS. 115 


There is a subglobose variety (apparently the stagnicola 
of Mr. Sheppard) which is flattened towards the ventral 
margin, and has the pellucid and swollen umbones pecu- 
liarly prominent. 

The dimensions of the larger typical form are six lines 
and a quarter in length, and five lines in breadth; of the 
variety, five lines and a half in length, and four and three- 
quarters in breadth. 

The animal is white, its subelongated siphonal tubes 
tinted with pale flesh-colour. Mr. Jenyns observes, that 
the superior tube is subconic, with a small aperture, the 
inferior cylindric and truncate, with a wider aperture. Mr. 
Glover notes on the variety flavescens, “ from running water, 
under stones,” that its animal is straw-coloured. 

For “ this very common species, a general inhabitant of 
rivers, ponds, and ditches throughout the country, which 
appears to thrive equally well both in running and in stag- 
nant water” (Jenyns), we do not cite any particular locali- 
ties, reserving the space thus gained for less thoroughly 
investigated species. 

Cyclas cornea is‘generally distributed throughout Europe, 
and occurs fossil in freshwater strata of the Pleiocene age 


im the valley of the Thames. 


C. caricutara, Draparnaud. 


Shape more or less rhombic; umbones narrow, more or less 
prominent, capped. 


Plate XX XVII. fig. 7 (as lacustris), and (animal) pl. O, fig. 7. 
Cyclas caliculata, DRAPARN. Moll. Ter. et Fluy. France, p. 130, pl. 10, f. 14, 
15.—Turr. Manual L. and F. W. Shells, p. 14, pl. 1, f.3.— 
Brown, Illust. Conch. G. B. p. 94, pl. 39, f. 28.— Lam. 
Anim. s. Vert. (ed. Desh.) vol. vi. p. 269.—Preirr. Deutsch. 
Land und Siissw. Moll. pt. 1, p. 122, pl. 5, f. 17, 18. — 
Nizsson, Moll. T. et Fl. Suecie, p. 99. — Kicxx, Moll. 
Brabant, p. 89. — Drsu. Encycl. Méth. Vers, vol. ii. pt. 2, 


116 CYCLADIDA. 


p- 37.—HAn.Ey, Recent Shells, vol. i. p. 89.—Gras, Moll. 
T. et Fl. de la France, p. 73, pl. 6, f. 5.—Puitippi, Moll. 
Sicil. vol. ii. p. 214. 
Cardium lacustre, Mont. (1803) Test. Brit. p. 89. 
Tellina lacustris, Linn. Trans. vol. viii. p. 60.—Turr. Conch. Diction. p. 180.— 
Woon, General Conch. p. 197, pl. 47, f. 5. —Diniw. Recent 
Shells, vol. i. p. 104. 
Cyclas lacustris, Tur. Dithyra Brit., p. 249, pl. 11, f. 18.—FLem. Brit. Anim. p. 
453. — Apr, Trans. Nat. Hist. Soc. Newcastle, vol. i. p. 
40.—Gray, Manual L. and F. W. Shells, p. 281, pl. 1, f. 3. 
Brown, Illust. Conch. G. B. p. 94, pl. 39, f. 20. 
This the most delicate and fragile of our Cyclades is of 
a slightly rounded subrhombic shape, almost smooth (at 
least, devoid of all regular striulz), diaphanous, and scarcely 
inequilateral. xcept upon the umbonal region, where the 
shell is moderately ventricose, the valves are compressed, 
not merely below, but also more or less on either side of the 
beaks. The surface is lustrous, and of a greyish ash- 
colour, and occasionally zoned also with yellow at the ven- 
tral margin, which latter is moderately arcuated, and rises 
rather the more anteriorly. ‘The umbones, which lean a 
little forward, are narrow, very projecting, and as it were 
capped (their surface becoming suddenly elevated above 
the remaining area, as if surmounted by another pair of 
younger valves), furnish the peculiar feature by which the 
species may most readily be distinguished from its British 
congeners. The margin on either side of them is nearly 
equally elevated, declines but little, especially behind, and 
is scarcely convex. Both extremities are broad, and not 
very unequally ; so the posterior which (especially in the 
young) is more or less subbiangulated, rather exceeds in 
width the rounded extremity of the slightly shorter anterior 
side. The ligament is small, inconspicuous, not elevated 
above the dorsal surface, and usually almost colourless. 
We have described the smaller and more ordinary form, 


but a much more produced angulated and compressed 


CYCLAS. 117 


variety, measuring occasionally seven lines by five and a 
half, has been taken in Clumber Lake by Mr. Jeffreys. 
That gentleman has likewise sent us for our inspection a 
peculiarly aberrant specimen from Cork (entirely agreeing 
with one taken by ourselves from a foul-smelling pool com- 
municating with the river Lea; S. H.), wherein the pro- 
jecting umbones are not capped at all, but the contour is 
precisely that of the preceding variety. In the two latter 
forms, the edges (especially the ventral) are straighter than 
usual, and the hinder dorsal edge is rather ascending than 
otherwise. 

We have preferred, on reconsideration, the epithet 
caliculata, bestowed upon this species by Draparnaud, 
partly from its expressiveness, partly because that author 
is said by Dupuy and others (we have not seen a copy 
ourselyes) to have published the name in 1801, in a Pro- 
dromus to his posthumous and larger work, and partly to 
avoid the confusion which our mention of the C. lacustris 
of the continental writers among our less positively ind1- 
genous species, would otherwise induce. The Tellina 
lacustris of Miiller (1774), which seems too imperfectly 
defined for assured identification, is almost invariably 
cited for the following shell. 

The animal, as observed by Mr. Jenyns, is entirely 
white. Its siphonal tubes are much elongated, and resem- 
ble those of cornea. The length of a fine individual was 
seven lines, and its breadth five and a half. There are 
two principal varieties; the first, which is of a rufous 
brown, is less pellucid and compressed and more rounded 
in contour than the type; the second, which resembles the 
preceding in the other points of diversity, is of a reddish 
cast, and displays but a slight degree of prominence at its 
blackish beaks. 


118 CYCLADIDA. 


It is by no means one of our commoner shells, and is 
apparently less infrequent in the north than in the more 
southern parts of England. Mr. Alder has found it near 
Newcastle, Mr. Bean at Scarborough (where it is not 
scarce), Mr. Thompson at Lichfield; and Capt. Brown 
records the vicinity of Manchester and the lakes of West- 
moreland for its localities. Montagu met with it in Devyon- 
shire and Wiltshire, Mr. Jenyns at (var. 1.) Bookham Com- 
mon in Surrey, and more sparingly in Cambridgeshire, 
and Mr. H. Strickland at Hornsea in Yorkshire. Mr. 
Jeffreys has taken it in the Clumber lake, Notts, and in 
the neighbourhood of Bristol. 

In Ireland, observes Mr. Thompson, it is also rare and 
local, but occurs in the east and south; it has been taken 
from a pond in the Phenix Park, the Grand Canal, and 
elsewhere in the vicinity of the metropolis; also at Cork, 
Youghal, &e. 

On the Continent it occurs in Sweden, Germany, Bel- 
gium, France and Italy. The C. partumeia of Say, in 
despite of the ventricosity of the adult, is very closely allied, 
especially in outline, to this species, and may be regarded 
as its transatlantic representative. 


C, racusrris, Draparnaud. 


Cyclas lacustris, Drap. Moll. Terr. et Fluy. France, p. 130, pl. 10, f. 6, 7.— 
Turt. Manual Land and Fresh-water Shells, p. 14, pl. 1, 
f. 4.—Gray, Manual Land and Fresh-water Shells, p. 17, 
pl. 1, f. 4.—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 268. 
—C. Prerr. Deutsche Land und Siissw. Moll. pt. 1, p. 122, 
pl. 5, f. 6, 7. — Kicxx. Moll. Brabant, p. 88. — Gras, Moll. 
Terr. et Fluv. France, App. p. 23 (copied from Draparnaud). 


It is from specimens in the valuable collection of Mr. 
Jeffreys, marked ‘“‘ Exmouth, 1831, and Dr. Turton’s ca- 


CYCLAS. 119 


binet,” that we have drawn up our description of a shell 
which we have never observed as British elsewhere, and 
which, even as avowedly foreign, is of very rare occurrence 
in the cabinets of Great Britain. 

Shell subrhombic, elongated, ovate, thin, inequilateral, 
rather compressed, especially below, where the valves meet 
each other at an acute angle, yet a little swollen mmmedi- 
ately beneath the umbones. Surface with rugose concentric 
striule, covered with a rather dull epidermis of a cinereous 
or yellowish ash-colour, with some indistinct grey linear rays 
towards the margin. Hinge-margin rectilinear, but higher 
behind than in front, scarcely at all declining on either 
side. Ventral edge arcuated near the middle, ascending 
rather considerably in front, thus attenuating the anterior 
side below. Posterior side decidedly, though not so very 
greatly, the longer, subbiangulate, the lower corner being, 
however, more or less rounded off; posterior edge not 
much rounded. Anterior extremity much the narrower, 
obliquely rounded below, obtusely subangulated above. 
Umbones semitransparent, very little projecting, broad and 
blunt. Dorsal area edged with opaque white. 

The largest individual measured five lines in length, and 
seven in breadth. The general look of the species was that 
of a greatly produced caliculata, devoid of the characteristic 
prominent beaks. We did not venture to open the valves, 
but the interior is described by Pfeiffer as having a pale 
bluish tinge, and Draparnaud tells us that the central teeth 
are not apparent, and the lateral very small. Brown’s 
figure does not at all agree with the shell we have been de- 
scribing, nor his assertion that its general contour is more 
orbicular than others of the genus. We have not ventured 
to cite either the Tellina lacustris of Miiller, or the Cyclas 
lacustris of Nilsson, as the umbo of the former is stated to 
be acute, the contour of the latter to be orbicular-sub- 
rhombic. 


120 CYCLADIDA. 


PISIDIUM. PFeirrer. 


Shell equivalve, thin, usually tumid, suboval, inequilateral, . 
smooth or concentrically striated. Hinge with one tooth 
in the right and usually two in the left valve; also lateral 
teeth. Ligament external, inserted at the shorter side. 

Animal suboval, with the mantles freely open in front 
and anteriorly, posteriorly united to form a single siphon 
composed of the united anal and branchial tubes ; margins 
of its orifice and of the mantle simple. Foot large, lingui- 
form, and very extensile. 

Very small bivalves living in similar localities with Cyclas, 
and not uncommon even in drains through meadows. Like 
the allied genus they are ovoviviparous, and the young 
have more compressed shells than the adult. The British 
species of both Pisidiwm and Cyclas have been most ably 
investigated by the Rev. Leonard Jenyns. 


* Sides not peculiarly unequal. 
P. oprusa.e, Pfeiffer (?). 


More or less swollen, very finely striolate ; umbones rather 
projecting and very obtuse. 


Plate XXXVI. fig. 1. 


Pisidium obtusale, C. P¥EIFFER, Deutsch Land und Sussw. Moll. pt. 1, p. 125, 
pl. 5, f. 21, 22 (probably). — Jenyns, Trans. Cambridge 
Phil. Soc. vol. iy. p. 301, pl. 20, f. J, 2, 3. —Gray, Ma- 
nual L. and F. W. Shells, p. 282, pl. 12, f. 149.—Brown, 
Tllust. Conch. G. B. p. 94, pl. 39, f. 24. 
Cyclas obtusalis (not of Lamarck), Nizsson, Moll. Terr. et Fluy. Sueciz, p. 101 
(probably).—HAn ey, Recent Shells, vol. i. p. 90, suppl. 
pl. 9, £. 47. 


The shape of the present species, which may be distin- 
guished from its British congeners by its more swollen 


PISIDIUM. 12 


valves, is rounded oval, and but slightly oblique. It is 
tumid, the profundity nearly equalling the breadth, glossy, 
and clothed with an epidermis of a greenish black or dusky 
ochraceous hue, margined by a zone of a dirty yellowish or 
somewhat orange-coloured tint, which in the young is more 
especially broad. Occasionally, but rarely, the entire sur- 
face, which is finely striated in a concentric direction, is of 
an uniform dull yellowish tinge. The sides are only mo- 
derately unequal; the ventral edge is much arcuated, and 
ascends the more on the shorter side. Both extremities are 
rounded (they are not very unequal in breadth); that of 
the longer side is a little more symmetrically and taperingly 
so. There appears to be more curvature of the hinder 
dorsal edge (and consequently less angularity at the upper 
posterior corner) than exists in pusi/lum. The umbones 
are tumid, obtusely rounded, and slightly prominent. 

There is an elongated and swollen variety, the form of 
which is triangular or ovate-trigonal, with the ventral mar- 
gin extremely obtuse. It is of a blackish hue, more or less 
stained with ochre-colour. 

Mr. Jenyns, whose authority we have chiefly followed in 
our account of the Pisidia, and to whose courtesy, in the 
communication of specimens and information we are highly 
indebted, first published this species as a British animal. 
We confess that we have experienced much difficulty in 
determining the limits of this and pusilla, although the 
small ventricose examples of the former, in which the mar- 
ginal zone is well developed, and the umbones are promi- 
nent, may be easily separated from larger-sized compressed 
typical forms of the latter, where the colouring is uniform, 
and the umbones not at all projecting. 

Ordinary specimens do not generally exceed the ninth 
of an inch in length, but some are occasionally obtained 


VOL. Il. R 


122 CYCLADIDZ. 


measuring a line and three-quarters in length, and a line 
and a half in breadth. 

The animal, according to Mr. Jenyns, is white. Its 
siphonal tube is abbreviated and more subconic. The 
foot is more than half the length of the shell. 

‘Tt oceurs not unfrequently in Cambridgeshire, inhabit- 
ing small splashy pools and other stagnant waters,” and is 
likewise taken in Surrey (Jenyns). 

In Ireland it is by no means common, but is recorded to 
have been taken in Down and Tipperary; in the latter at 
Finnoe, in the former from a pond at Portavo, and from a 
drain in the clay-soil of a brick-field near Bangor. (Thomp. 
Ann. N. H. vi. p. 195.) K. Mancey (Mr. Barlee). 

Mr. Jeffreys and Mr. Barlee procured it from Balma- 
carra in W. Ross; and Captain Brown, who first an- 
nounced it as British, found it under the columnar greenstone 
rocks, at the west end of Arthur’s Seat, near Edinburgh, 
and plentifully in a ditch (now covered up by the railway) 
at the Wells of Weary. Mr. Jeffreys once dredged a 
dead specimen of this species in forty fathoms water off 
Tarbet in Loch Fyne, to which extraordinary locality it 
had probably found its way in consequence of having been 
washed into the water by a stream. 

From the delineation by Delessert of the Lamarckian 
example of Cyclas obtusalis we ascertain with certainty 
(what was previously suspected), that our own species is not 
precisely identical with Lamarck’s, which, if any of our 
British shells (the description is most inadequate, and no 
locality is cited), is probably pusidlum. Pfeiffer seems to in- 
dicate our typical form, and Nilsson the produced variety. 


PISIDIUM. js 


P. pustttum, Turton. 


Rounded oval, not greatly inequilateral, not distinctly striated ; 
valves not swollen, always a little compressed below: umbones 
usually broad and but little projecting. 


Plate XX XVII. fig. 10, and (Animal) Plate O, fig. 9. 


Cyclas fontinalis, DRAPARN. Moll. Terr, et Fluy. France, p. 130, pl. 10, f. 8—12 ? 
Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 270 2—Nitsson, 
Moll. Sueci, Terr. et Fluy. p. 101.—Desu. Encye. Méth. 
Vers, vol. ii. pt. 2, p. 37 2—Hanu. Recent Shells, vol. i. p. 
90, suppl. pl. 14, f. 45—Gras, Moll. T. et Fl. France, p. 
73, pl. 6, f. 3, 42 

Tellina pusilla, Turv. Conch. Diction. p. 167. 

Cyclas Turt. Dithyra Brit. p. 251, pl. 11, f. 16, 17; Manual of Land 

and Freshw. Shells, p. 16, pl. 1, f. 7. 

Cyclas gibba, Atpur, Trans. Nat. Hist. Soc. Newcastle, vol. i. p. 41. 

Pisidium pusillum, JENYNS, Trans. Cambridge Phil. Soc. vol. iv. p. 302, pl. 20, 
f. 4, 5,6.—Gray, Manual L. and F. W. Shells, p. 283, 
pl. 1, f. 7.— Mace. Moll. Aberdeens. p. 253.— Brown, 
Ill. Conch. G. B. p. 95, pl. 39, f. 27. 


As in most Pisidia, there is a considerable latitude of 
diversity in shape permitted to this species, which conse- 
quently, although typically orbicular-oval, becomes some- 
what oblong in certain individuals. It is small, thin, semi- 
pellucid, and but slightly (for its genus) inequilateral ; the 
valves, although not really compressed, appear so when 
compared with P. obtusale, although actually they are ven- 
tricose or nearly so. The surface is not regularly striolated, 
is usually concealed by a rustlike coating, and is never 
highly lustrous, but ranges from rather dull to rather 
glossy. The colouring, which is generally uniform in tint, 
displaying neither zones nor a marginal band, is of a light 
fulvous hue, and occasionally so pale as almost to become a 
squalid white. The ventral margin is regularly arcuated, 


ascending much and almost equally at both ends. The 


194 CYCLADIDE. 


longer anterior side has its extremity tapering, and almost 
symmetrically rounded ; the posterior termination is broad- 
ly and very bluntly rounded, but is subangulated above 
from the little curvature of the very short and scarcely de- 
clining hinder dorsal edge. The ligament is scarcely per- 
ceptible ; the umbones are broad, and but little projecting. 

From the valves becoming more quickly shallow (the 
profundity is chiefly confined to the umbonal region) than 
in obtusale, they meet below at an acute angle. There 
exists a variety in which the umbones are less blunt and 
more prominent; and another shining one, on which the 
striule are more distinctly graven. The extreme length 
is a line and three-quarters, the breadth is nearly a line 
and a half. 

The animal, according to Jenyns, is white, with a short 
entire margined siphonal tube, which varies its shape from 
cylindrical to subconic. The foot is a little longer than the 
length of the shell. 

This is apparently by far the commonest of the smaller 
Pisidia, being a frequent and abundant inhabitant of ponds. 
Among other localities we may specify Scarborough (Bean); 
Preston (Gilbertson); Northumberland and Durham (AI- 
der); Coggeshall, Essex (S. H.); Exmouth (Clark); near 
Swansea (Jeffreys); Aberdeenshire (Macgillivray); near 
Bantry Bay (Jeffreys) ; and, indeed, is universally distri- 
buted in Ireland, where (as in Scotland likewise) Mr. 
Thompson has met with it in marshy spots, adhering to the 
same stones as the land mollusca, and occasionally has 
taken it from moss only moistened by the spray of a water- 
fall) (Ann. NSE volaviep: 195). 

It inhabits Northern and Central Europe. 


PISIDIUM. 125 


* * Valves very inequilateral. 
P. crnereum, Alder. 


Broadly ovate, greyish or cinereous, rather compressed, finely 
striated ; margin of the valves meeting at rather an acute angle ; 
umbones obtuse, and not much produced (sometimes a little 


capped). 
Plate XXXVI. fig. 2. 


Pisidium cinereum, ALDER, Suppl. Cat. L. and F. W. Moll. Northumb. p. 4 ; 
Mag. Zool. and Bot. vol. ii. p. 119.—Gray, Manual of 
L. and F. W. Shells, p. 286, pl. 12, f. 152.—Tuome. 
Ann. Nat. Hist. vol. vi. p. 196.—Brown, IIl. Conch. G. 
B. p. 95, pl. 39, f. 28. 

Cyclas cinerea, HANLEY, Recent Shells, vol. i. p. 90, suppl. pl. 14, f. 44. 


This species, as Mr. Alder observes, is the largest of our 
minute Pisidia ; and may readily be distinguished, for the 
most part, from its congeners, by its more compressed shape 
and ashy hue. Its form is somewhat obliquely obovate, its 
valves are rather compressed, and its surface is covered 
with a shining epidermis of a greyish ash-colour, which 
sometimes becomes paler at the margin, and is somewhat 
narrowly zoned at the stages of growth with a darker tint 
of the same colour, and only irregularly, and occasionally 
somewhat indistinctly, striclate in a concentric direction. 
The posterior side is much the shorter and decidedly the 
broader ; its width is, however, a little diminished below 
by the greater rise of the ventral margin (which is more or 
less arcuated) on that side. The produced anterior side is 
moderately attenuated, but rounded at its extremity. The 
dorsal edges are short, and their declination is very trifling ; 
there is usually a slight angulation, especially behind, 
where they unite with the lateral margins. The ligament 


is very indistinct. The umbones are broad, obtuse, not 


126 CYCLADIDA. 


much produced, and sometimes are slightly capped, as in 
Cyclas caliculata. 

A variety exists which is rather more ventricose, and 
produced at the umbones. 

The length is one-fifth of an inch, and the breadth nearly 
two lines. 

It inhabits ponds, at Scarborough (Bean), in the north of 
England (Alder), Preston (Gilbertson), Clumber Lake in 
Nottinghamshire, the Croydon Canal, and at Cadley, near 
Swansea (Jeffreys), Bath and Exmouth (Clark). 

It is widely distributed, although not common, through- 
out Ireland (Thompson), as in various parts of Antrim, in 
a moist spot in the wood at Holywood House in Down 
(and elsewhere in that county), at Youngrove, near 
Middleton in Cork (C. Wright), Killereran in Galway, 
Portarlington, and the vicinity of Dublin. In Scotland 
it has been taken at Balmacarra, West Ross (Jeffreys). 
The Sicilian P. australe of Philippi (Moll. Sicil. vol. 1. 
p- 125, pl. 14, f. 11) is apparently identical. 


P. niripum, Jenyns. 


Orbicular-oval, extremely glossy, with fine strie, and a few 
deeper ones upon the umbonal region : umbones rather blunt. 


Plate XX XVII. fig. 14. 


Pisidium nitidum, Junyns, Trans. Cambridge Phil. Soe. vol. iv. p. 304, pl. 20, 
f. 7, 8.—Gray, Manual of L. and F. W. Shells, p. 283, 
pl. 12, f. 150.—THomp. Ann. Nat. Hist. vol. vi. p. 195.— 
Macey. Moll. Aberd. p. 253.—Brown, II]. Conch. 
G. B. p. 95, pl. 39, £ 26. 

Cyclas nitida, HANLEY, Recent Shells, vol. 1. p. 90, suppl. pl. 14, f. 46 (not well). 


This species can with difficulty be distinguished from 
pusillum or obtusale, especially in the immature state, and 


PISIDIUM. bir 


the validity of its specific separation must rest rather upon 
the animal than the shell. Nevertheless, when well deve- 
loped, its umbonal sulci will afford to the accurate observer 
a ready means of discriminating it: these, however, de- 
mand a most searching examination for their discovery. 
The general shape is of a rounded oval; it is slightly more 
convex than the preceding species and broader in propor- 
tion to it; is highly lustrous and rarely, if ever, clothed like 
it with a rusty or muddy coating. The general surface 
is only obsoletely striated at intervals, but the umbonal 
region is concentrically traversed with a few regular sulci, 
whose interstices often appear like elevated striule. The 
umbones themselves are rather obtuse, projecting but little 
above the dorsal line. The larger examples are an eighth 
of an inch in length, and not much inferior in breadth. 

The animal, according to Jenyns, is white; its siplion 
short and funnel-shaped, with a patulous aperture, the 
margin of which is more or less crenated or plicated. 

Mr. Jenyns obtained his original specimens from ditches 
in Battersea Fields, and other parts of Surrey, as well as 
from various spots in Cambridgeshire, where (he observes) 
it is widely dispersed, though seldom plentiful, and_ is 
seemingly partial to clear water. Mr. Jeffreys has ob- 
tained it from Clumber Lake in Nottinghamshire, and at 
Sandwich in Kent; Mr. Bean from Scarborough; Mr. 
A. Hancock in Northumberland, and Mr. W. Backhouse 
near Darlington. 

In Wales it has been found at Oxwich near Swansea, 
and Tenby and Manorbeer in Pembrokeshire (Jeffreys). 

It is generally distributed in Ireland, and abundant in a 
cold turfy deposit conveyed by a mountain-stream to a 
pond at Wolfhill, near Belfast, and on the Utricularia 


vulgaris growing in stagnant pools near that town ; Lough 


128 CYCLADIDZ. 


Gill in Sligo, Portarlington and Finnoe, in Tipperary, 
likewise furnish it (Thompson, Ann. N. H. 6, p. 195); 
Mr. Jeffreys has examples from Cork, collected by Mr. 
S. Wright, jun. 

In Scotland it has been taken from a millpond near 
the new bridge of Don in Aberdeenshire (Macgillivray), 
where, however, it is of rare occurrence. Mr. Barlee has 
taken it at Bracadale and Portree, in Skye, and at other 


localities in the west. 


P. putcHEeLtum, Jenyns. 


Small, striated (not grooved) ; umbones simple, and without 
appendage. 


Plate XX XVII. fig. 12 and 13. 


2 Pisidium fontinale, PFEIFFER, Deutsch. Land und Sussw. Moll. pt. 1, p. 125, 
1b Bh te Wes, WG 
Cyelas fontinalis, Brown, Edinburgh Journ. of Nat. and Geograph. Science, vol. 
les pepl legpleplaptetGay/c 
Pisidium pulchellum, JENYNS, Trans. Cambridge Phil. Soc. vol. iy. p. 306, pl. 
21, f. 1, 2, 3,4, 5.— Gray, Manual L. and F. W. 
Shells, p. 284, pl. 12, f. 151.—Macertuiv. Moll. Aber- 
deens. p. 252. 
Cyclas pulchella, HANL. Recent Shells, vol. i. p. 91. 
Pisidium fontinale, Brown, Ill. Conch, G. B. p. 94, pl. 39, f. 23. 
Pisidium Jenynsti, MAceituiv. Moll. Aberdeens. p. 249. 
35 Johannis, 5 5 p. 248. 


It would be a bold assertion were we to declare that form 
is no characteristic in the Pisidia; yet this species might 
well bear us out in the hypothesis, such a multiplicity 
of contour does its aspect present ; with the most opposite 
forms, however, so gradually merging into each other that 
it is absolutely impossible to determine where each variety 
commences. Although no two forms seem more remote 


than typical specimens of the varieties @ and 6, the for- 


PISIDIUM. 129 


mer with the shape obliquely oval, the profundity of 
the valves not extending to the margin, and the front 
extremity rounded; the latter with the outline subrhom- 
boidal oblong and devoid of obliquity, the anterior end sub- 
biangulated, and the ventricoseness so pervading the entire 
shell that the lower margins almost form a rectangle at 
their meeting: yet intervening examples certainly do occur, 
knowing which we dare not subdivide pulchellum, as was 
once proposed by its author, who, in a recent communica- 
tion to us, again reverts to his original opinion of the in- 
tegrity of the species. One character, although varying in 
intensity, is commen to all the varieties, viz. the presence 


of regular concentric strie. 


Var. @. Rather large, obliquely oval, ventricose, rather 
deeply striated ; the umbones rather obtuse and 
simple (Jenyns, pl. 21, f. 1). 

Var. 8. Usually smaller and more finely striated ; the um- 
bones rather acute (Jenyns, pl. 21, f. 2, 3). 

Var. y. Obliquely oval, finely striated, compressed; mar- 
gins meeting at an acute angle. 

Var. 5. Subrhomboidal oblong, swollen almost equally 
throughout, deeply striated; margins meeting 
at more than acute angles (Jenyns, pl. 21, 
f. 4, 5). 


For the varieties « and y the name Jenynsii has been 
proposed by Mr. Gray, in honour of the Rey. Leonard 
Jenyns, who has so ably treated a genus which presented 
such difficulties in its investigation, that after a long and 
wearisome examination of its members, we have adopted 
throughout (although with some little hesitation) the 
species and varieties suggested in his valuable monograph. 
In our eyes the variety 6 appears the least connected with 


s 


130 CYCLADIDA. 


the rest, and most worthy, if any, of separate specific im- 
portance. We may remark, by the by, that this form is 
much more likely to prove the Zedlina pusilla of Gmelin, 
derived from Schréter’s description and rough delineation 
of a Hamburg shell (Flussconch. p. 194, pl. 4, f. 7), which 
he terms swollen and concentrically striated, than that 
which we have followed Mr. Jenyns in so denominating in 
these pages; but in truth the synonymy of continental 
Pisidia is so doubtful, that, in default of adequately long 
descriptions and correctly enlarged drawings of their 
species, we are unwilling to originate any changes in the 
nomenclature of our British ones. 

The animal, according to Jenyns, is white: its siphon is 
polymorphous, short or elongated, cylindric, truncate or 
obtuse at apex, with an entire or a lacerated margin, vary- 
ing at various times. 

The largest examples we have seen (kindly lent us by 
Mr. Thompson) came from Lochnaw in Wigtonshire, and 
measured two lines and a quarter in length, and one line 
and three-quarters in breadth. A line and a half by a line 
and a quarter are the average dimensions of the variety 6. 

In Cambridgeshire it is very common in rivers, ditches, 
and likewise the smallest streams (Jenyns); has been 
found also in Northumberland (Alder), at Scarborough 
(Bean), Preston (Sowerby), Battersea Fields and Book- 
ham Common (var. 6) in Surrey (Jenyns), in the ponds and 
ditches of Northumberland and Durham, not uncommon, 
(Alder), and at Cadley near Swansea (Jeffreys). 

It is generally distributed in Ireland, remarks Mr. 
Thompson, “ where it inhabits stagnant and running water 
of the least as well as the greatest extent, and at the same 
time and place may be found on various subaquatic plants 


” 


and buried in the mud.” The largest and finest specimens 


PISIDIUM. 131 


come from the gently flowing Main, near its junetion with 
Lough Neagh (Thompson); it is found at Killarney 
(Barlee), Cork (S. Wright, jun.), &e. &e. Capt. Brown, 
who first distinguished it as a British species, states that his 
specimens came from a ditch at Duddingston Loch, near 
Edinburgh, and from another at Hunter’s Bog, King’s Park. 
Professor Macgillivray enumerates it among his Aberdeen- 
shire Mollusca. Its foreign distribution is uncertain. 


P. HENsLow1AnuM, Sheppard. 


The umbones furnished with a lamelliform projection. 


Plate XX XVII. fig. 11. 


Tellina Henslowiana, SHerPARD, Linn. Trans. vol. xiv. p. 150. 
Cyclas appendiculata, Turr. Manual L. and F. W. Shells, vol. xv. pl. 1, f. 6. 
—Hantey, Recent Shells, vol. i. p. 91, suppl. pl. 14, 
f, 42 (copied from last). 
Pisidium Henslowianum, JeENyNs, Trans. Cambridge Phil. Soc. vol. iv. p. 308, 
pl. 21, f. 6, 7, 8, 9—Gray, Manual L, and F. W. 
Shells, p. 285, pl. 1, f 6—Brown, Ill. Conch. G. 
B. p. 95. pl. 39, f. 25. 
Pisidium acutum, L. Prurrrer, Wiegm. Archiv. f. Naturg. 1831, pt. 1, p. 230. 


There is very little to distinguish this species from 
pulchellum (to which eventually it may possibly be 
united) except the very extraordinary appendage upon 
the umbones. The shape is obliquely ovate, and very in- 
equilateral ; the valves are not very ventricose (in some 
exotic ones they are rather compressed), and are of a horn or 
yellowish horn colour, and more or less closely striolate in 
a concentric direction. The surface seems generally more 
or less glossy ; the ventral margin is moderately curved and 
rises the more behind. The produced anterior side tapers 
both above and below to a rounded tip, which lies usually 
rather below the middle; its upper edge is rather the less 


132 CYCLADIDA. 


convex. The posterior end is of the ordinary shape in this 
genus,—that is to say, blunt, rounded below, and subangu- 
lated above; the hinder margin itself is not greatly convex ; 
the dorsal edge is straightish and rather slopmg. The 
chief profundity is decidedly at the umbonal region, the 
anterior end being manifestly compressed, and the valves 
being generally more or less pinched in on either side of the 
umbones. These last are rather acute, and are furnished 
with a small laminar eave-like projection, which in the 
adult occupies quite the summit of the shell, appearing 
like a ridge rising up vertically on either side of the hinge, 
but in the young looks like a small wing proceeding from 
the middle of the shell. 

Specimens which measured two lines and a half in length, 
and two lines in breadth, are recorded by Mr. Jenyns, 
—dimensions far exceeding the average of our examples. 

The animal, according to Jenyns, is white, with a short, 
generally subconic, siphonal tube. 

This is a rare shell, which was first discovered by Pro- 
fessor Henslow in ditches communicating with the river 
Cam, in the immediate neighbourhood, and a few miles 
below Cambridge (Jenyns). It is likewise met with in 
Suffolk (Sheppard); in the Thames at Henley (Strick- 
land), at Cadley, near Swansea (Jeffreys), and at Finnoe 
in Tipperary (Thomp. Ann. N. H. 6. p. 196). 

It has been noticed in Germany. As a fossil, it is found 
in the freshwater pleistocene beds of Grays and elsewhere 
in the south of England. 


PISIDIUM. 133 


P. amnicum, Miller. 


Not minute ; extremely inequilateral, sulcately striated ; um- 
bones not very blunt. 


Plate XX XVII. fig. 8, 9, and (Animal) Plate O, fig. 8. 


Tellina amnica, MuuuEr, Verm. Terr. et Fluv. pt.2, p. 205.— Linn. Trans. 
vol. villi. p. 60.—Turt. Conch. Diction. p. 168.—Dorset 
Catalog. p. 31, pl. 7, f. 2,a.— Woon, General Conch. p. 153, 
pl. 47, f. 6.—Dimuw. Recent Shells, vol. i. p. 105.—Index 
Testaceolog. pl. 3, Tell. f. 19. 
rivalis, Maton, Linn. Trans. yol. iii. p. 44, pl. 13, f. 37, 38. —Donov. 
Brit. Shells, vol. ii. pl. 64, f. 2. 
Cardium amnicum, Mont. Test. Brit. p. 86. 
Cyclas palustris, DRAPARN. Moll. Ter. et Fluy. France, p. 131, pl. 10, f. 15, 16. 
—Gras, Moll. T. et F. de la France, p. 73, pl. 6, f. 6. 
» obliqua, LAM. Anim. s, Vert. (ed Desh.) vol. vi- p. 269.—Nuxsson, Moll. 
Suecize, T. et Fl. p. 99.—Kickx, Moll. Brabant, p. 89. 
Pisidium obliquum, PrrtrreR, Deutsch. Land und Sussw- Moll. pt. 1, p. 124, 
pl. 5, f. 19, 20.—Brown, Illust. Conch.-G. B. p. 94, pl. 
39, f. 22.—Puiiept, Moll. Sicil. vol. ii. p. 31. 
Cyclas amnica, Tur. Dithyra Brit. p. 250, pl. 11, f. 15.—Frem. Brit. Anim, 
p- 453.—Turt. Manual L. and F. W. Shells, p. 15, pl. 1, f.5. 
—Han try, Recent Shells, vol. i, p. 89, pl. 3. f. 19. 
Pisidium amnicum, JeNyNs, Trans. Cambridge Phil. Soc. vol. iv. p, 309, pl. 
2S fs 2. 


” 


The outline of this species, which is by far the largest 
of our British Psidia, is more or less obliquely subovate 
(often displaying a disposition to become triangular) and 
extremely inequilateral. The valves of the adult are mo- 
derately ventricose (in the young they are much more 
compressed) ; the profundity is chiefly manifested at the 
subumbonal portion, their lower part being much more 
shallow; they are thin, fragile, glossy, semitransparent, 
and generally more or less incrusted with ferruginous mat- 
ter. The surface, which is concentrically traversed by rather 
irregularly developed sulci, whose interstices often assume 


the appearance of raised subimbricated strize, is of an oll- 


134 CYCLADIDA. 


vaceous ash-colour, and is broadly zoned at the margin of 
the larger examples with a paler or yellowish tint. It 
is sometimes, though rarely, observes Mr. Jenyns, of 
an uniform brownish or yellowish hue; sometimes, 
too, ashy-brown with lighter spots. The ventral margin 
is moderately curved behind, but arcuated and much 
ascending in front. The anterior side, which is much 
produced, is compressed and tapering at its extremity, 
where it is almost symmetrically rounded ; the upper edge, 
however, is rather more sloping and slightly less convex. 
The hinder side is extremely short, and its termination is 
very blunt, the posterior edge being but little convex, and 
almost forming a rounded off rectangle with the basal mar- 
gin; the upper corner also, from the straightness of the 
dorsal edge, which has a slight but distinct declination, is 
subangulated. The ligament is but little conspicuous; the 
umbones are not broad, nor much prominent. The interior 
is white with a bluish cast. 

The dimensions of the full-grown shell are ordinarily 
five lines and a quarter in length, and three lines and three- 
quarters in breadth. 

The animal is white, the siphon rather variable in shape, 
sometimes abbreviated, sometimes subconic; the apex is 
obliquely truncated, and often more or less recurved. The 
foot is often protruded to a great length as compared with 
the size of the shell. 

Although not so frequent as Cyclas cornea, this is one of 
our most abundant fluviatile shells. Dr. Maton, who first 
defined it as a distinct member of our Fauna, obtained his 
specimens from the Avon, near Salisbury, and Montagu 
from the north Avon: it is extremely plentiful in the New 
River, near London (S. H.), where it partially imbeds it- 


self in the mud, never rising (as certain other Pisidia) to 


PISIDIUM. 135 


the surface of the water; is found in the Thames at Wit- 
ney, Henley, &c., as well as in the Severn (Strickland). 
Scarborough (Bean), the vicinity of Bristol (Jeffreys), and 
of Bath (Clark), the water-courses of the meadows near 
Wareham in Dorsetshire (Brown), &c., are among its 
English localities. In Wales, it hasbeen procured by Mr. 
Jeffreys in the neighbourhood of Swansea and of Cardiff, 
at Ragland Castle in Monmouthshire, &c. 

In Ireland, observes Mr. Thompson, “although not very 
common, it is widely distributed over the island, and is 
known to me as occurring in every portion except the ex- 
treme south” (Ann. N. H. vol. 6, p. 196): in the river 
Liffey (where it is plentiful), it attains a very large size, 
and is taken in the Main, near its junction with Lough 
Neagh (as well as in the rejectamenta of the latter), at 
Limerick, Miltown Malbray, Ballitore in Kildare, &c. It 
is found near Edinburgh, as well as in many other parts of 
Scotland (Brown). 

It is generally distributed throughout Europe, and occurs 
fossil in the pleistocene freshwater beds of the Thames. 


136 


UNIONID. 


Tue fresh-water mussels, as the members of this family 
are popularly called, are very closely allied to the marie 
mussels, and differ chiefly in the structure of the foot of 
the animal which, in the tribe before us, is greatly deve- 
loped in dimensions, and is not provided with a byssal 
groove. Mr. Anthony, an American conchologist, how- 
ever, asserts that under peculiar circumstances certain 
North American species do spin a byssus both in the young 
and adult states.* As in several of the genera of Mytilide 
the mantle has its margins, which cannot be reflexed, 
freely open almost throughout, and the siphons are only 
indicated by a difference in the structure of the posterior 
borders, the shells vary greatly in form and aspect. 
Those of our few native species are more or less oblong, 
and depressed, but so great is the variation among foreign’ 
species, that an American naturalist observes, there seems 
to be a representation of the forms of all the genera of 
marine bivalves in this tribe. All the Unionide are equi- 
valve. They are covered with an epidermis which is often 
remarkable for brilliancy of colour, a feature also of the 
pearly surfaces of the insides of their valves. 

The variation of the hinge is very great in this tribe, 
and its value as a source of character has been a subject of 
much discussion among conchologists. Some, as Mr. G. 


* Letter to J. E. Gray, in Annals Nat. Tist. vol. vi. 


UNIONIDA. 137 


Sowerby, have gone so far as to propose the union of all 
the genera in one, whilst others, as Mr. Swainson have 
maintained the other extreme, and not only divided the 
tribe into numerous genera, but have even grouped them 
into sub-families. The tribe, as a group, is a very natural 
one; the genera are, we fear, too nearly inclined to arti- 
ficial sections, and of the extreme opinions, that of Mr. 
Sowerby approaches nearest the truth. There are, how- 
ever, in the family a few types of character, round which a 
number of species seem to group themselves naturally : the 
sections Unio and Anodon to which, with most authors, 
we refer our British species, are of this nature and may 
conveniently be retained. The value of the generic divi- 
sions at best, however, in this tribe, is not equal to that 
assumed by such sections in most of the other tribes we 
have passed in review. 

The Unionide all inhabit fresh-waters. But few com- 
paratively are found in the old world, by far the greater 
number being inhabitants of America. In the United 
States alone there are more than two hundred species. 
The collections made by Major Cautley and Dr. Falconer, 
among the Siwalik fossils would seem to indicate that 
during tertiary epochs the species of the old world were 
more numerous than they now are. The tribe ranges far 
back in time. All the species are very variable, and it is 
extremely difficult to assign their precise diagnoses. 

The bisexuality of the animals of this family was first, 
we believe, observed by Professor Bell in Europe, and by 
Dr. Kirtland in America. The shells of the females are 
more ventricose than those of the males. 

The distribution of the British fresh-water mussels is 
peculiar and significant of the four species we possess. ‘Three 
are members of the genus Unio and one of Anodon. 


VOL, II. T 


138 UNIONIDA. 


The last is generally distributed through England, Scotland 
and Ireland; one of the Uniones, that representing the 
section Margaritana or Alasmodon is partially distributed 
in the three countries, confining itself to the mountainous 
portions, and the rapid streams which flow from them. 
The remaining two are confined to England, and abundant 
mainly in the south and east. On the continent the 
Alasmodon abounds in the Scandinavian rivers beyond the 
range of its fellows, which, however, have an almost uni- 
versal distribution through central and southern Europe. 
The former species does not range south of the Alps. 
Taking the features of this distribution into consideration, 
it seems as if the Unio margaritifera had migrated south- 
wards from some ancient northern centre, whilst the other 
Uniones and the Anodonta advanced westwards and north- 
wards, with unequal pace, however, since only the last in- 
vaded Ireland. The fossil contents of the fresh-water 
tertiaries contemporaneous with or immediately preceding 
the period of the drift, when the greater part of the British 
isles was under sea, corroborate this view, for in them 
we find associated together the Unio tumidus and pictorum 
and the Anodonta cygnea. 


UNIO. Rerzius. 


Shell equivalve, often thick, inequilateral, very variable 
in shape (oblong in the British species) smooth, or furrowed, 
or nodulous on the surface, and covered with a coloured 
epidermis ; beaks eroded. Hinge with primary teeth, and 
with or without elongated laterals; ligament external, 
more or less elongated. Muscular impressions conspicuous, 
pallial scar simple. 

Animal shaped like the shell, thick, mantle freely 


UNIO. 139 


open in front and anteriorly, with simple edges ; branchial 
region fringed with numerous cirrhi, anal tube-like, plain. 
Foot large, broad, compressed. Labial palps ovate. 

The rivers of North America swarm with species of this 
beautiful genus, but in Europe we have very few, and in 
Britain only three forms. A fourth, Unio Uittoralis, still 
living in France and other parts of the continent, inha- 
bited our area during the pleiocene epoch, but has long 
since disappeared. 

Schumacher constituted his genus Margaritana for those 
Species in which the lateral tooth is not developed, and 
Say made his Alasmodon for the same section, Unio being 
retained for species with both cardinal and lateral teeth. 
We prefer keeping them together on account of their great 
similarity of habit. Lately Dr. Troschel (in Wiegmann’s 
Archives for 1847) has attempted to found distinctions 
between the several genera of Naiades on the characters of 
the branchize and lips. The peculiarities he describes in 
his excellent paper do not appear to be more than 
specific. 

The shells of this genus have frequently been used by 
painters for containing their colours, and some of the 
species furnish pearls. The animals are not eaten in our 
country, but in the south of Europe,—where everything in 
the shape of shell-fish is devoured with an avidity which 
defies starvation as long as rivers and seas yield mollusca 
in their present abundance—they are cooked for food, 
either roasted in their shells and drenched with oil, or 
covered with bread-crumbs and scalloped. 


140 UNIONIDZ. 


U. rumipus, Retzius. 


Solid : umbones with confluent, concentrically disposed, angu- 
lar wrinkles ; anterior teeth high and conical. 


Plate XL. fig. 1. 


Unio tumidus, Rerzius, Nova Genera Test. p. 17.— Gray, Manual Land and 
F, W. Shells, p. 297, pl. 2, f. 13. — Brown, IIl. Conch. G. B. 
p- 82, pl. 32, f. 5, 6, 7, 8. —Spxeneu. Skriv. Natur. Selsk. 
Kiobenh. vol. iii. pt. 1, p. 57. — Przrrrer, Deutsch. Land und 
Stssw. Moll. pt. 2, p. 34, pl. 7, f. 2, 3, and pl. 8, f.1,2; pt. 2, 
pl. 2, f. 25, (Young).—Kuickx, Moll. Brabant. Austral. p. 83.— 
Rossmas. Iconog. Land und Siissw. Moll. pt. 1, p. 117, pl. 3, 
f. 70; pt. 2, p. 27, pl. 14, f. 202, 203, 204; pts. 7, 8, 
p. 41, pl. 40, f 542; pt. 12, p. 32, pl. 60, f. 772 to 778. — 
Hant. Recent Shells, vol. i. p. 205, pl. 2, Mya, f. 27. 
Mya ovalis, Puttrenry, Hutchins, Hist. Dorset, p. 27 (fide Mont.) — Monr. 
Test. Brit. p. 34. 
» depressa, Donovan, Brit. Shells, vol. iii. pl. 101. 
» ovata, Donovan, Brit. Shells, vol. iv. pl. 122. Maron and Rackerr, 
Linn. Trans. vol. viii. p. 39.— Tur. Conch. Dict. p. 106. — 
Woop, General Conch. p. 105, pl. 19, £. 5. — Dittwyn, Recent 
Shells, vol. i. p. 50.—Index Testaceolog. pl. 2, Mya, f. 27. 
Mysca ,, Turr. Dithyra Brit. p. 246; Manual Land and F. W. Shells, 
p. 21, £. 12: 
»  solida, Turt. Dithyra Brit. p. 246, pl. 16, f. 2; Manual Land and F. W. 
Shells, p. 22, f. 13. 
Unio ovalis, FLeminG, Brit. Anim. p. 416.— Brown, Ill. Conch. G. B. p. 82, 
pl. 31, f. 1, 2, 3, 4.-SowErBy, Genera Shells, Unio, f. 1.— 
REEVE, Conch. Systemat. vol. i. pl. 87, f. 1. 


The principal difficulty in describing the Uniones, is to 
avoid laying that stress upon characters which, in most 
other genera, would probably be held of specific value, but 
here, from their extraordinary power of modifying both 
contour and colouring, become of minor importance. In 
this respect the present shell (at least in our native exam- 
ples) does not vie with the succeeding: nevertheless, 
briefer language than usual is requisite, that the characters 


assigned to it may prove sufficiently broad and compre- 


UNIO. 141 


hensive. Its valves are of an elongated ovate or ovate-ob- 
long shape, thick, unequally ventricose, (the hinder portion 
being always much more compressed than the frontal), and 
with their umbones typically more or lessswollen. The ex- 
ternal surface, which has no other sculpture than the rugose 
lines of increase (the umbonal wrinkles, which are subtuber- 
cular and angularly disposed, alone excepted) is more or 
less radiatingly painted all over, the colour of its epidermis 
ranging from dusky olive to a clear ochraceous yellow 
adorned with rays of a pure bluish green; it is occa- 
sionally, however, of an uniform olivaceous brown. The 
ventral edge ascends in a well arcuated sweep anteriorly, 
is either straightish or curved out a little in the middle, 
and rising behind, often with some degree of suddenness, 
in a slightly convex line, forms, with the upper margin, a 
conical posterior beak, of which the bluntly-pointed apex 
(occasionally a little truncated in the young) is either sub- 
central or below the middle of the side. The dorsal edge, 
typically rather short in proportion, is nearly straight and 
level on both sides; the upper posterior edge declines mode- 
rately and is straightish, or slightly subretuse. The anterior 
side, which occupies from one-quarter to one-third of the 
entire Jength, is unsymmetrically rounded at its extremity, 
the upper corner being often angulated from the comparative 
straightness of the dorsal line, and the ventral ascent being 
always more oblique than the upper declination. The liga- 
ment is rather large and projecting ; the prominent umbones 
are not usually broad, and have generally a well-marked 
impression before them. The internal nacre seems almost 
always of a bluish white (rarely of a salmon colour); the 
primary teeth are strong, and a little compressed, the hinder 
of the left valve being thick and conspicuously erect ; the 


lateral lamine are produced and devoid of crenulations. 


142 UNIONIDA. 


A fine specimen measured three inches in length, and 
rather more than half that breadth at the widest part. 

The animal has plain white edges to its mantle. The 
branchial portion is mottled with orange brown, and fringed 
with numerous short cirrhi ranged in several irregular 
rows along the inner edges. The anal portion forms a 
plain edged tube-like projection, about half as wide as the 
former, and of a darker colour being more or less striped 
with purplish brown. The foot is of pale orange tint, thick 
and broad. ‘Troschel observes that the lips are broader 
than long, and united together for half their hinder margin. 
The outer branchial leaflet is united to its end with the 
mantle; the inner one is free and not combined with the 
foot. 

It is found in the New River, in the Avon, and Kennet, 
the Ouse, and several rivers in the east of England, not 
ranging northwards beyond the south of Yorkshire. In 
the Ely river, Cardiff (Jeffreys). On the continent it is 
chiefly plentiful in France, Belgium, and Germany. 


U. picrorum, Linneus. 


Posterior end not cuneiform ; umbonal tubercles small, not 
confluent ; anterior teeth compressed, elevated, sometimes crested. 


Plate XX XIX. fig 1, and (Animal) plate Q. fig. 2. 


Lister, Hist. Conch. pl. 147, f. 3. — Scurérer, Flussconch. 
pl. 4, f. 6. 
Mya pictorum, Linnzus, Syst. Nat. ed. 12, p. 1112. — Pennanv, Brit. Zool. 
ed. 4, vol. iv. p. 79, pl. 43, f. 17.— Da Cosra, Brit. Conch. 
p- 228, pl. 15, upper f. 4. — Maron and Racr. Linn. Trans. 
vol. viii. p. 38. — Dorset Catalog. pl. 12, upper f. 4. — Turron, 
Conch, Diction. p. 106.—Linn. Fauna Suecica, ed. 2, p. 516.— 
Sturm, Deutsch. Fauna, Wurmer, pt. 2. — Woop, General 
Conch. p. 104, pl. 19, f. 834. — Dintwvn, Recent Shells, vol. i. 
p. 49.—Index Testaceolog. pl, 2, Mya, f. 26. 


UNIO. 143 


Mya ovalis, Donoy. Brit. Shells, vol. iv. pl. 89.—Monr. Test. Brit. p. 34. 
Unio pictorum, DRAPARNAUD, Moll. Terr. et Fluy. France, pl. 11, f. 4. —FLEM. 
Brit. Anim. p. 416. — Gray, Manual Land and F. W. Shells, 
p- 295, pl. 2, f. 11—Brown, Illust. Conch. G. B. p. 8], pl. 31, 
f. 7, 9, 10,11. — Lamarck, Anim, s. Vert. (ed. Desh.) vol. vi. 
p- 541 (partly). — Pretrrer, Deutsch. Land und Siissw. Moll. 
pt. 1, p. 115, pl. 5, f. 9, 10, and pt. 2, pl. 2, f. 24 (Young).— 
Ninsson, Moll. Suecize Terr. et Fluy. p. 111.-— Biarny. Man. 
Malacologie, pl. 67, f. 2.—Croucn, Introd. Conch. pl. 9, f. 4.— 
Kickx Moll. Brabant. Austral. p. 84.—RossmAsLER, Icon. 
Land und Sussw. Moll. figs. 71, 196, 409, 587, 588, 589, 
590, 741, 762, 763, 764, 765, 767, 768, 769, 780. — Hani. 
Recent Shells, vol. i. p. 205, pl. 2, Mya, f. 26. 
» rostrata, LAMARCK, Anim. s. Vert. (ed. Desh.) vol. vi. p. 540. — Brown, 
Ill. Conch. G. B. p. 82, pl. 32, f. 9,10. — PrrmrreEr, Deutsch. 
Land und Sussw. Moll. pt. 1, p. 114, pl. 5, f. 8.—KicKx, Moll. 
Brabant. Austral. p. 83. — MicHaup, Comp. Moll. Ter. et Fluv. 
France, p. 108, pl. 16, f. 55.— Gras, Moll. Terr. et Fluv. 
France, p. 71, pl. 5, f. 21. 
Mysea pictorum, Turron, Dithyra Brit. p. 245 ; Manual L. and F, W, Shells, 
p: 20, f. 11. 
Unio limosus, Niusson, Moll. Sueciz Terr. et Fluv. p. 110. —Rossmas. Iconog. 
Land und Sussw. Moll. pt. 3, p. 24, pl. 13, f. 199. 
»  Deshaysit, MicHaup, Comp. Moll. T. et Fl. France, p. 107, pl. 16, f. 30.— 
Brown, Illust. Conch. G. B. p. 81, pl. 32, f. 1 to 4.—Ross- 
mas, Iconog. Land und Siissw. Moll. pt. 3, p. 23, pl. 13, 
f. 197.—Gras, Moll. Ter. et Fluv. France, App. 
»  longirostris, Z1mGL. in Rossmis. Iconog. pt. 3, p. 26, pl. 14, f. 200 and 
pt. 12, p. 13, pl. 54, f. 38. 
Encyclop. Méthod. Vers, pl. 248, f. 4. 


Although our synonymy of this well-known Unio may 
seem tolerably copious, it might without much difficulty be 
considerably enlarged, and embrace several other supposed 
species (at least we surmise so) without straining too far 
the elastic law of variation. As it is, we have followed the 
dictum of Rossmisler, whose ample opportunities of study- 
ing and comparing the diversified and aberrant forms of the 
Uniones of an entire continent, must impart to his opinion 
a far higher value than our own more limited experience 
can pretend to. Nevertheless, we may remark as a curious 
fact, that we do not observe in his delineation of the Con- 


144 UNIONID®. 


tinental forms of this polymorphal shell, any of which our 
Islands do not exhibit a nearly analogous representative. 
If a certain platitude of language be demanded in a descrip- 
tion of the preceding species, far more highly requisite is it 
that our diagnosis of the present one should be sufficiently 
inclusive. 

The contour varies from a produced oval to elongated 
oval oblong, the texture from actually solid (it is rarely, if 
ever, so in our British examples) to rather thin and fragile. 
The valves are ventricose, but the profundity is rather dif- 
fused, the umbonal region in place of tumidity more fre- 
quently exhibiting a sort of compression, which, carried 
downwards to the basal margin, usually displays itself in a 
greater or lesser retusion of that portion of the shell. No 
sculpture, unless the rugose lines of increase be regarded as 
such, adorns the exterior ; but two radiating series of small 
isolated (not confluent) narrow tubercles are visible upon 
the umbones. ‘The epidermis is of an olivaceous yellow 
(for the most part changing into green posteriorly, near the 
obscure umbonal fold), is generally zoned with brown at the 
stages of growth, and rarely, if ever, displays any distinct 
radiation at any other portion of its surface. The dorsal 
and ventral margins run almost parallel; the former is 
almost horizontal, and nearly upon the same level on either 
side of the beaks; the latter rises obliquely and arcuatedly 
in front, but ascends very gently, if at all, at. the posterior 
end. Similarly the declination of the posterior margin in 
the more typical examples is very moderate, and the edge 
itself short in proportion to the hinder dorsal outline; 
hence the termination of the shell is never cuneiform as in 
tumidus, but the tapering portion is generally short, and 
the beak, whose tip is either below the middle or at most 
subcentral, is more or less obtusely subtruncated. The 


UNIO. 145 


anterior side, except in being rather narrower, resembles 
that of the preceding species; and occupies about two- 
sevenths (more rarely one-third) of the entire length. The 
hinder margin in the more characteristic specimens is at 
first retuse and then convex; in others it is almost entirely 
rectilinear ; in others again (yet seldom so) it is actually 
arcuated. The ligament is elongated and projecting. The 
umbones are not particularly prominent, and are often 
broad. The internal nacre is silvery-white in general, but 
occasionally stained with salmon colour: the primary teeth 
are coarsely crenated, very much compressed, and the 
hinder one of the left valve small or obsolete; the lateral 
lamin are simple, and much produced. 

A large individual measured full three inches in length, 
and nearly an inch and a half in breadth. 

A somewhat tortuous variety is taken in the River Lea, 
near London, and in the northern districts of England, 
with the rostrum bending below the level of the incurved 
ventral margin, and with the hinder side either greatly pro- 
duced or with its upper edge arcuated. In this form the 
primary teeth are apt to become rudimentary. 

The animal has the front margins of its mantle plain 
and white. The branchial portion is of an orange-brown, 
mottled with lighter and darker specks. It is of greater 
extent than in the last species, and rather more finely 
fringed. In a moderate-sized specimen about two hundred 
and fifty cirrhi may be counted. The anal portion of the 
mantle is darker, and is radiatingly striped near its mar- 
gin with purplish-brown. The edges are quite smooth, 
and approximate so as to form a pretty complete promi- 
nent tube, quite distinct from the branchial region and 
from the hinder angulated portion of the mantle. The 
foot is very large, thick, broad, slightly apiculated, and 

VOL. II. U 


146 UNIONIDA. 


of a pale yellowish-white colour. The labial palps are 
ovate. 

Its distribution is similar to, but rather wider than that 
of the last species, and has been greatly extended through 
the agency of canals. The Kennet, Avon, Ouse, Aire, 
Don, and Severn include it among their inhabitants, also 
the canals about London, Birmingham, and Hull. Staf- 
fordshire, in Chillington Pool (Jeffreys); Shrewsbury 
Canal, and near Eyton (Eyton); Scarborough (Bean). 
“Mr. Hogg states that it has been found in the ponds at 
Wynyard, on the authority of Sir W. C. Trevelyan, Bart. 
It has not been met with further north.” (Alder). 

Generally distributed throughout the less mountainous 
and plain parts of Europe, from Sweden to Naples. 


U. marcanritirerus, Linneus. 


Solid : epidermis black ; no lateral teeth. 


Plate XXXVIII. as Alasmodonta margaritifera. 


ListER, Hist. Conch. pl. 149, f. 4. 

Mya margaritifera, Linn. Syst. Nat. ed. 10, p. 671 5 ed. 12, p.1112 ; Fauna 
Suecica, ed. 2, p.516.—PENNANT, Brit. Zool. ed. 4, vol. iv. 
p- 80, pl. 43, f. 18.— Da Costa, Brit. Conch. p. 225, 
pl. 15, f. 3—Donov. Brit. Shells, vol. iii. pl. 73.—Monv. 
Test. Brit. pp. 33, 561.—Maron and Rack. Linn. Trans. 
vol. viii. p. 40.—Mu.ueEr, Verm. Terr. et Fluv. p. 210. 
—Turv. Conch. Diction. p. 106. f. 47. — CHEmN. Conch. 
Cab. vol. vi. p. 15, pl. 1, f. 5. — Dintw. Recent Shells, 
vol. i. p. 52. — Index Testaceolog. pl. 2, Mya, f. 30. 

Die Perlenmuschel, ScHROTER, Fliissconch. p. 168, pl. 4, f. 1. 

Unio margaritiferus, Ruvzius, Nova Genera Test. p. 16. — Turr. Dithyra Brit. 
p. 242, pl. 16, f. 1; Manual L. and F. W. Shells, p. 19, 
pl. 2, f. 9.—Forses, Malacol. Monensis, p. 44. — SPENG- 
LER, Skrift. Nat. Selsk. Kiobenh. vol. iii. pt. 1, p. 52.— 
Draparn, Moll. Terr. et Fluv. France, pl. 11, f. 5.— 
Preirrer, Deutsch, Land und Siissw. Moll. pt. 1, p. 116, 
pl. 5, f. 11.—Nusson, Moll. Suecize Terr. et Fluy. p. 103. 


UNIO. LAT 


— Kickx, Moll. Brabant. Austral. p. 82. — RossMAsL. 
Iconog. Land und Siissw. Moll. pt. 1, p. 120, pl. 4, f. 71, 
2,73, 74; pt. 2, pl. 8, f. 129. — Hanu. Recent Shells, 
vol. i. p. 213. 
Unio elongata, LAM. Anim. s. Vert. (ed. Desh.) vol. vi. p. 531.— Nuixsson, Moll. 
Sueci Terr. et Fluv. p. 106.— Micuaup, Comp. Moll. Terr. et 
Fluy. France, p. 113, pl. 16, f. 29.—Gras, Moll. Terr. et Fluv. 
France, Append. p. 22. 
Alasmodonta arcuata, BARNES, Silliman’s Journal, vol. vi. p. 277, pl. 12, f. 20.— 
Gou.p, Invert. Massach. p. 113, f. 75 (Alasmodon). 
Unio sinuata, Pretr. Deutsch. Land und Siissw. Moll. pt. 2, p. 33, pl. 7, f. 4. 
»  Rotssyi, MicHaup, Comp. Moll. Terr. et Fluv. France, pl. 16, f. 28 (fide 
Rossm.) 
Alasmodon margaritiferus, FLEMinG, Brit. Anim. p. 417.—Gray, Manual Land 
and F. W. Shells, p. 293, pl. 2, f. 9. — THompson, 
Ann. Nat. Hist. vol. vi. p. 197. — Macerttiv. Moll. 
Aberd. p. 242.-— Brown, Ill. Conch. G. B. p. 83, 
PSO Ladle oe seplolemtanls aoa plelOcante las 
Wes ay 
Margaritana margaritifera, Lea, Trans. Americ. Phil. Soc. vol. vi. p. 135. 


The arcuated shape, and consequent incurvation of the ven- 
tral margin, in most examples of this well-known bivalve, 
has induced the separation of the straighter individuals as 
a distinct species. Believing as we do, that the Naiades 
have been most unnecessarily subdivided and multiplied, 
we have felt disposed to include likewise the U. sinuatus of 
Lamarck, but have been deterred, by the high authority 
of Rossmisler and Deshayes, from thus extending our 
synonymy. 

The ordinary form is oval-oblong, or elongated kidney- 
shaped ; the valves are thick and strong, compressed when 
young, moderately ventricose when adult, covered with a 
strony epidermis of an uniform pitchy black (which is of a 
lighter or yellow cast in the immature specimens) smoothly 
spread upon the disk, but more loosely disposed towards 

‘the margin and posteriorly ; occasionally the surface is 
obsoletely waved with very obscure concentric plice. The 


ventral margin is either incurved, straight, or at most very 


148 UNIONIDA. 


slightly convex, and rises much more obliquely, and consi- 
derably in front than behind. The anterior dorsal edge is 
never retuse, but either arcuated or slightly convex ; it 
runs almost parallel to the opposite outline, the attenuation 
and occasional blunt subrostration of the hinder termina- 
tion not extending far towards the beaks. These latter 
are almost always eroded, displaying the olivaceous nacre 
of the scarcely elevated umbones. The anterior side occu- 
pies but little more than a fourth of the entire length, and 
is rounded at its narrowed extremity, but not symmetri- 
cally so, the declination of the upper portion of the more or 
less arcuated upper edge not being so oblique as the slope 
of the lower one ; just above the teeth there is a short sub- 
retusion of the dorsal edge, but except in the young no 
distinct lunular impression. The basal corner of the hinder 
end is well rounded; the upper posterior corner is often 
obtusely angulated in the immature shell, but in the full- 
grown one no angle exists, as the posterior edge forms an 
almost uninterrupted curve with the elongated hinder 
dorsal. There is no prominent umbonal fold, but a gra- 
dually widening slight hollow runs from the umbones 
adjacent to the dorsal edge, indenting the margin a little 
at its termination. The ligament is long, but its projection 
is very trifling. The internal nacre, which is of a bluish- 
white, frequently flesh-coloured towards the centre, gene- 
rally stained with irregular spots or markings of bronze or 
green, and usually impressed near the middle with scat- 
tered indented dots, does not extend to the margin, but 
leaves a greenish border beyond it. The front muscular 
scar is very profound; the twin teeth of the left valve are 
erect, strong, and subconical or pyramidal, the posterior’ 
with four or five denticles upon its front surface, the an- 


terior narrower, entire, and more or less pointed ; the sin- 


UNIO. 149 


gle opposing tooth of the right valve is broad, erect, a 
little twisted, somewhat arched, and deeply grooved at its 
apex. 

Specimens are recorded to have reached the length of 
five and a half inches, and the breadth of two and a half 
inches; the majority of individuals do not measure above 
four and a half inches long and scarcely two broad. 

The animal of this species has a white-margined mantle 
and foot. Troschel describes the lips as being broader than 
long, and united for two-thirds of their length. The outer 
branchial leaflets are free posteriorly, and lie in a fold of 
the mantle; the inner ones are partially united with the 
foot. 

The Pearl Mussel, as this mollusk is familiarly called, 
enjoys a distinguished reputation as one of the few in- 
digenous bivalves which yield the beautiful productions 
whose name it bears. In ancient times Britain enjoyed 
some celebrity for its pearls, and they constituted one of its 
attractions for Julius Ceesar ;* who, however, does not seem 
to have reaped a very rich harvest, so far as quality went, 
though he obtained enough in quantity to cover with them 
a buckler, which he dedicated to Venus Genetrix, and sus- 
pended in her temple.f The pearls used for the construc- 
tion of his present were probably such as Roman ladies 
would have scorned to wear, although they were osten- 
tatiously offered to the goddess of beauty, for Pliny, who 
narrates the circumstance, states at the same time that the 
pearls from Britain were small and lustreless, and not to be 
compared with those from the East. Tacitus, in his life of 
Agricola, describes the pearls of Britain as “ subfusca ac 
liventia,” and among ancient Christian writers they are 
mentioned by Origen and Bede. Pennant, and other 


* Suetonius. t Pliny, ix. ch. xxxv. 


150 UNIONIDZ. 


writers who have treated of pearls, have all taken it for 
granted that those mentioned by the ancient authors quoted 
were derived from the Unio. This, however, is by no 
means clear, and Czsar’s buckler was more probably 
covered with pearls from Mytilus edulis, very much in- 
ferior in quality and size to those from the fresh-water 
Pearl Mussel, and agreeing better with the disparaging 
account of them in Pliny. Those mentioned by Camden* 
as occurring at the mouth of the Irt, in Cumberland, seem 
to have been of the same nature. The pearl-fishery at the 
mouth of the Conway, to which we shall have hereafter to 
refer, also concerns the Mytilus and not the Unio. Higher 
up the latter river, however, and in many rivers of all parts 
of the kingdom, especially in the neighbourhood of moun- 
tainous districts, the Unio has been at various times fished 
to a great extent for pearls, and, in all probability, the fame 
of British pearls that attracted the Roman conqueror was 
due to the products of the shell before us. The best account 
of any of these fisheries of the freshwater Pearl Mussel is 
contained in a curious paper in the seventeenth volume of the 
‘“* Philosophical Transactions” (1693), written by Sir Ro- 
bert Redding, and communicated by Dr. Martin Lister. 
This paper has been often referred to by subsequent writers, 
who, however, seem to have made use of Pennant’s short 
notice of it only, which itself was taken from the abridg- 
ment, and not from the original. It is a remarkable paper 
on account of the correctness of observation displayed in the 
personal statements of the author, who seems to have been 
a person with considerable natural-history powers. His de- 
scription of both shell and animal is curiously correct as far 
as it goes. He states that they were fished in the rivers of 
Tyrone, Derry, Donegal, near Dundalk, near Waterford, 


* Britannia ; Gough’s edition. Vol. iii. p. 189. 


UNIO. LD 


and in Kerry. The poor people fished them in the warm 
months before harvest-time, when the rivers were low. 
They took them with their toes, or wooden tongs, or by 
thrusting a stick into the shells which they caught sight of 
among the stones as they lay in part opened, with the white 
foot protruded “like a tongue out of the mouth.” Sir 
Robert saw them lying on their sides, and his informants 
described them as “set up in the sand like eggs in salt, 
with the sharp edge downwards, and the opening side turn- 
ed from the torrent.” One in a hundred might contain a 
pearl, and of about one in a hundred of the pearls was tole- 
rably clear. There were no pearls in the young mussels. 
‘Some gentlemen of the country made good advantage 
thereof, and I myself whilst there saw one pearl bought 
for fifty shillings that weighed thirty-six carats, and was 
valued at forty pounds. Everybody abounds with stories 
of the good pennyworths of the country, but I will add one 
more. A miller took out a pearl which he sold for four 
pounds ten shillings, to a man who sold it for ten pounds, 
who sold it to the late Lady Glenealy for thirty pounds, with 
whom I saw it in a necklace ; she refused eighty pounds for 
it from the late Duchess of Ormond.” “The pearl,” Sir 
Robert observes, ‘‘ lies in the toe, or lesser end, at the ex- 
tremity of the gut, and out of the body of the fish, between 
the two films or skins that line the shell.” He remarks 
that they correspond with calculi in other animals. 

The pearls of the Conway had great fame. According to 
Pennant a notion prevails in Wales, ‘“ that Sir Richard 
Wynne of Gwydir, chamberlain to Catherine, Queen to 
Charles the Second, presented her majesty with a pearl 
from the Conway which is to this day honoured with a 
place in the regal crown.” He says the Pearl Mussels are 
called by the Welsh Cregin diluw, or Deluge Shells, as if 


152 UNIONIDA. 


left there by the flood.* Mr. Wilson of Warrington, in 
Loudon’s ‘* Magazine of Natural History” for June, 1830, 
says they are taken in the upper part of the Conway, near 
Llanrwst, but the search is very precarious. He mentions 
a Scotch pearl half an inch in diameter. In Scotland, the 
Tay was the seat of a pearl-fishery, extending from Perth 
to Loch Tay. ‘It is said,” writes Captain Brown, “ that 
the pearls sent from thence to London, from the year 1761 
to 1764, were worth ten thousand pounds sterling; and it 
is not uncommon at the present time to find pearls in the 
Teith and Tay worth from one to two pounds each.” The 
variety Loissyi of this Unio was formerly much sought for 
in the river near Braddan, in the Isle of Man, on account 
of its pearls. 

In the ninth volume of the “ Philosophical Transactions” 
(1674) there are two letters from Hamburgh, by the 
learned Christophorus Sardius, concerning the origin of 
pearls. ‘The pearl-shells in Norway and elsewhere,” 
writes this author, ‘‘ do breed in sweet water. Their shells 
are like to those which are commonly called mussels, but 
they are larger. The fish in them looks like an oyster, but 
it produceth a great cluster of eggs like those of cra-fishes, 
some white, some black (which latter yet will become 
white, the outer black coat being taken off). These eggs, 
when ripe, are cast out, and being cast out they grow, and 
become like those that cast them. But sometimes it hap- 
pens that one or two of these eggs stick fast to the sides of 
the matrix, and are not voided with the rest. These are 
fed by the oyster against her will, and they do grow, ac- 
cording to the length of time, into pearls of different big- 
nesses, and imprint a mark both in the fish and the shell by 


the situation, conforming to the figure.” The editor of the 


* Brit. Zool. iy. p. 80. 


UNIO. 153 


“‘ Transactions” very properly wrote to Mr. Sardius for 
proof of his assertion, and was informed, in reply, that it 
depended on a certain Dane, named Henricus Arnoldt. 
This account of the origin of pearls is on a par with the old 
poetical fancy of their origin from drops of dew. We need 
scarcely remind our readers that they are of the same 
nature with the inner coats of the shell, and are abnormal 
secretions of the mantle, composed of alternating and con- 
centric layers of membrane and calcareous matter. 

The Pearl Mussel is an inhabitant of rapid streams flow- 
ing from mountainous districts. Cumberland, Westmore- 
land, and Northumberland, in the north of England,—the 
streams of the hilly parts of Devon and Cornwall in the 
south,—many of the rivers of Wales, both north and south, 
—the streams of the Isle of Man,—the rivers flowing from 
the Highlands of Scotland, and many Irish rivers,—are its 
chief localities. Abroad it is found abundantly in Norway 
and Sweden ; sparingly in mountainous districts of France 
and Germany. 


Considerable difficulty has arisen from a statement by 
the late Dr. Solander, the pupil of Linnzus, that the Mya 
pictorum of the British Islands was not the species so 
designated by Linnzus ; a declaration either resulting from 
his having only seen the much commoner U. tumidus (at 
that time confused with it by the English conchologists), or 
from his knowledge of the Linnean types, a considerable 
portion of which (yet not those agreeing with the synonymy) 
is certainly of a form which we have not observed exactly 
delineated among the European Uniones, but not unlike the 
shell figured as MW. pictorum by Donovan (vol. vy. pl. 174), 
only broader in proportion to the length. Montagu having 


VOL. II. x 


154 UNIONIDA. 


fancied he recognized the Solandrian ideal in certain shells 
taken in the river Kennet, above Newbury, and Wood 
having cited these two English writers for his Mya Batava, 
(General Conch. p. 103, pl. 19, f. 1, 2, drawn from a 
worn Dutch specimen,) the Unio Batavus (a very different- 
looking shell from one forwarded to us by Dr. Philippi as 
that of the German writers, yet probably identical), has 
obtained footing in our English Fauna, first appearing 
under that specific epithet in Dr. Turton’s “‘ Manual of the 
Land and Freshwater Shells of the British Islands.” His 
figure (pl. 2, f. 10), which, as Mr. Gray justly observes, is 
more like a young Alasmodonta than any other British shell, 
appears to have been either copied from Wood or Schroter, 
—with the addition of umbonal wrinkles,—or else to be a 
filed down pictorum; it certainly is not taken from his own 
type (probably foreign, and added to his collection subse- 
quently), which by the kindness of Mr. Jeffreys has been 
forwarded to us, and is assuredly the true U. Batavus of 
the continental conchologists, well represented in Ross- 
miisler’s Iconographie, pl. 8, f. 128 a, but is much smaller, 
not quite measuring an inch and a quarter in length. It 
agrees somewhat better, except in size and colour (since it 
is rayed with green lines on a yellowish ground), with Tur- 
ton’s account in the Dithyra Britannica (p. 245), where he 
states his possession of it, and mentions Oxfordshire as the 
locality of the species; but differs completely from Montagu’s 
description of pictorum, and not a little so from Donovan's 
figure of that shell, both which latter we are inclined 
to regard as only varieties of the species correctly so 


termed. 


ANODONTA. 155 


ANODONTA, Bruegigre. 


Shell equivalve, ovate, usually rather thin, auriculated, 
inequilateral, closed. Beaks small. Hinge without teeth, 
but furnished with a lamina. Ligament external, linear. 
Pallial impression simple. 

Animal oblong, mantle freely open, with simple margins 
in front and anteriorly, but fringed with numerous short 
cirrhi in the branchial region, plain in the anal. Foot large, 
broad, compressed. Labial palps large, lanceolate. 

Like Unio this genus is chiefly American, only one dis- 
tinctly-marked species inhabiting Europe. The animal 
is very prolific. In spring and summer the branchial 
leaflets of the female of our native Anodonta may be found 
charged with minute, yet complete, shelled young ones, to 
the number of many thousands; and Mr. Lea of Philadel- 
phia, a naturalist who has done much towards the elucida- 
tion of the tribe, has calculated as many as six hundred 
thousand young Anodontas to be present in a single adult 


specimen three inches long. 


A. cyanea, Linneus. 


Plate XX XIX. fig. 38, XL. figs. 2 and 3, and XLI. and (animal) Plate Q. fig. 3. 


* Mytilus cygneus, Linn. Syst. Nat. ed. 12, p. 1158.-—- Da Cosra, Brit. Conch. 
p- 214. — Monr. Test. Brit. p. 17]. — Maron and Rack. 
Linn. Trans, vol. viii. pl. 3 a, f. 2.— Tur. Conch. Dict. 
p- 115.—Scurorer, Einleit. Conch. vol. iii. p. 440.—Pottr, 
Test. Sicil. vol. ii. p. 212, pl. 33, f. 1, 2.—SHEpparp, Trans. 
Linn. Soe. vol. xiii. pl. 5, f. 8. — Dintwyn, Recent Shells, 
vol. i. p. 815. — FLeminG, Encyclop. Edin. yol. vii. pl. 205, 
f, 16. 
anatinus, Linn, Syst. Nat. p. 1158. — Turr. Conch. Diction. p. 116.— 


” 


* For additional synonyms see varieties. 


156 UNIONIDA. 


Scurorer, Flussconch. p. 160, pl. i. f. 2, 3 ; Einleit. Conch. 
vol. iii. p, 442.—Index Testaceolog. pl. 12, Myt. f. 33. 
Mytilus stagnalis, SowERsy, Brit. Miscellany, pl. 16. — Turr. Conch. Diction. 
p- 115.—Ditiw. Recent Shells, vol. i. p. 316. 
s»  dentatus, Turt. Conch. Diction. p. 115. 
Anodonta (and Anodon) cygnea, DRAPARN. Moll. Terr. et Fluy. France, p. 134, 
pl. 11, f. 6, and pl. 12, f. 1.—Turvr. Dithyra Brit. p. 239; 
Manual Land and F. W. Shells, p. 17.—F Lem. Brit. Anim. 
p. 415.— Gray, Manual Land and F. W. Shells, p. 289.— 
Tuompson, Ann. Nat. Hist. vol. vi. p. 197.—Browy, Ill. 
Conch. G. B. p. 179, pl. 28, 28* ; 29, f. 1, 2, 3; pl. 30, 
f. 1 to 8. — Lamarck, Anim. s. Vert. (ed. Desh.) vol. vi. 
p-. 564, — Kickx, Moll. Brab. Austr. p. 80.— BLAINv. 
Manuel Malacolog. pl. 66, f. 1. — Hanu. Recent Shells, 
vol. i. p. 216.—Gras, Moll. T. et Fl.,France, p. 70. 
5 intermedia, LAM. Anim. s. Vert. (ed. Desh.) vol. vi. p. 568.—KENYON 
Mag. Nat. Hist. vol. i, f. 185, at p. 428.—Nuzsson, Moll. 
Suecie Terr. et Fl. p. 117. 
és anatina, Drap. Moll. Terr. et Fl. France, p. 133. — Turr. Dithyra 
Brit. p. 240. — Maceiitiv. Moll. Aberd. p. 241. — Lam. 
Anim. s. Vert. (ed. Desh.) vol. vi. p. 565. — Nizsson, 
Moll. Sueciw Terr. et Fl. p. 114. — Puiuipps, Moll. Sicil. 
vol. i. p. 67, vol. ii. p. 49. 
a ventricosa, Kick x, Moll. Brab. Austral. p. 80. 
»  paludosa, Tur. Dithyra Brit. p. 240, pl. 15, f. 5. 
»  piscinalis, Nitsson, Moll. Suecie Terr. et Fluv. p. 116. — RossmMAst. 
Iconog. Land und Siissw. Moll. pt. 4, p. 23, pl. 19, f. 281 ; 
pt. vi. pl. 30, f. 417. 
Symphonota cygnea, LEA, Obs. on Unio, vol. i. p. 70. 


We may aptly preface our account of this ubiquitous 
shell, with a paragraph from Mr. Gray’s excellent ‘‘ Manual 
of the Land and Fresh-water Shells of the British Islands.” 
It is truly, indeed, ‘‘a most variable species which appears 
to assume different appearances under every circumstance ; 
as for example, the depth, the stillness or motion, and the 
purity or impurity, or peculiar impregnation of the water 
in which it happens to be located.” After a wearisome 
examination of a multitude of forms, both native and 
foreign, not only must we dissent to the division of this 
polymorphous bivalve into those numerous species into 


which it has been separated by the continental writers, 


ANODONTA. 157 


but even demur to the possibility of arranging the diversi- 
ties of shape and colouring into strictly defined varieties, so 
imperceptibly does one form glide into another, scarcely 
indicating by any preponderance of peculiarities, under 
which heading it should be ranked. Still there are certain 
individuals so strongly characterised, that selecting them 
as centres we may group around them the majority of ex- 
amples, leaving, nevertheless, many specimens remaining, 
which, except by infinite subdivision of nomenclature, and 
the objectionable formation of subvarieties, cannot well be 
classified, but oscillate between the more marked variations. 
The typical form of the primitive cygnea (Mytilus cygneus, 
Scurérer, Fliissconch. pl. 3, f. 1.—Pernnanr. Brit. Zool. 
ed. 4, vol. iv. p. 113, pl. 67, f 78.—Donov. Brit. Shells, 
vol. u. pl. 55.—Maron and Rack. Linn. Trans. vol. viii. 
pl. 3a. f. 2.—Index Testaceolog. pl. 12, Myt. f. 32.— 
Myt. stagnalis, Gunnin, Syst. Nat. p. 3362, from Schriter 
Fliissconch. pl. 1. f. 1. — Wyt. anatinus var. b. Sturm, 
Deutsch. Fauna, pt. 1.— Anodonta cygnea, Brarpv, Coq. de 
Paris, pl. 10.—Pretrrer, Deutsch. Land und Siissw. Moll. 
pt. 1, p. 111, pl. 6, f. 4, and pt. 2, pl. 6.—Rossmas. Iconog. 
Land und Siissw. Moll. pt. 1, p. 111, pl. 3, f. 67, and pt. 5, 
pl. 25, f. 342.— Brown, Ill. Conch. G. B. pl. 28, f. 1) is 
oval or elongated oval, moderately and not very unevenly 
ventricose, and but little oblique or solid. The anterior 
side, which does not quite occupy one-third of the length is 
broadly rounded (occasionally angulated above) ; the pos- 
terior end is attenuatedly rounded, but not beaked, and 
devoid of peculiar retusion at the upper edge. From the 
dorsal and ventral margins running nearly parallel to each 
other (the latter is rather convex, the former straight or 
shghtly swelling and not rising into a wing), the two extre- 


mities of the shell are not so unequal as in several of the other 


158 UNIONID&. 


variations. The glossy epidermis is usually of a light and 
somewhat olivaceous yellow green, often changing into grey 
or ash colour upon the umbones, and adorned with two or 
three broad darker (often bluish-green) rays adjacent or 
beyond the umbonal fold. These rays, we may remark, 
are present in most of the varieties. The beaks and 
umbones are scarcely raised above the dorsal line; the 
former are flattened and very indistinct; the latter are 
channelled with small concentric folds. The nacre is 
silvery or occasionally of a pink or flesh-colour. The ob- 
secure pliciform wrinkles, which are indicated upon its sur- 
face, become more prominent features in Céllensis (Myt. 
anatinus, Penn. Brit. Zool. ed. 4, vol. iv. p. 113, pl. 68, 
f. 79.—Marton and Rack. Trans. Linn. Soe. vol. viii. pl. 3a. 
f. 1.—Suepparp, Trans. Linn. Soc. vol. xiii. pl. 5, f. 5.— 
Fem. Encycl. Edin. vol. vil. pl. 204, f 4.—Myt. Zellensis, 
Gmewin, Syst. Nat. p. 3362, from Schriter, Fliissconch. 
pl. 2, f. 1.—Anod. sulcata, Nitsson. Moll. Suecize Terr. et 
Fluy. p. 1138.—Anod. eygneus, Turr. Manual, (and Gray) 
Land and Fresh W. Shells, pl. 1, f.8.— Brown, IIl. 
Conch. G. B. pl. 28 (erroneously 27), f. 1—Anod. Cellensis, 
Prerirrer, Deutsch. Land und Siissw. Moll. pt. 1, p. 110, 
pl. 6, f. 1.—Rossmasst. Iconog. Land und Siissw. Moll. 
pt. 4, p. 22, pl. 19, f. 280), whose contour is still more 
elongated, its valves more unequally and subumbonally 
ventricose, its hinder end more beaked, its epidermis 
of a greyer tint, its basal margin retuse, and its dorsal 
line straight or slightly concave. In ventricosa (Anod. 
ventricosa, Preirrer, Deutsch. Land und Siiss. Moll. 
pt. 2, p. 30, pl. 8), the valves are solid and swollen, and 
rather more oblique than im the two preceding varieties. 
Its epidermis is olivaceous, its front extremity rather 
attenuated below; its hinder termination subrostrated : 


ANODONTA. 159 


its basal edge more frequently subretuse. The beaks 
seem rarely eroded in this form, but commonly so in the 
preceding. 

When in this species the hinder contour is broad and 
subrhomboidal, the dorsal line manifestly rising behind, so 
as somewhat to alate or render winged the upper posterior 
corner, and the ventral edge obliquely ascending in front atte- 
nuates below the anterior extremity, whilst sweeping up- 
ward behind it rounds off the subtruncated tip of the hinder 
termination, the shell is usually known by the name anati- 
nus, (Grande Moule des étangs, Grorr. Coq. Paris, pl. 3.— 
Mytilus anatinus, Da Costa, Brit. Conch. p. 215, pl. 15, 
f. 2.—Monr. Test. Brit. p. 171—Cuemn. Conch. Cab. 
vol. vii. pl. 86, f. 763.—Dimtw. Recent Shells, vol. 1, 
p- 317.—Anod. anatina, Lam. Anim. s. Vert. (ed. Desh.) 
vol. vi. p. 565.—F rem. Brit. Anim. p. 415.—Sowerpy, 
Genera Shells.— Reeve, Conch. Systemat. vol. i. pl. 91.— 
Rossmast. Iconog. Land und Siissw. Moll. pt. 6. pl. 30, f.417, 
420.—Hanu. Recent Shells, vol. i. p. 216.—Mytilus ma- 
cula, Surpparp, Trans. Linn. Soe. vol. xiii. p. 5, f. 6.— 
Anodon cygneus var. Brown, Il. Conch, G. B. pl. 29, f. 1). 
In this variety the epidermis is generally of a clear lustrous 
yellowish-green, for the most part faintly radiated with 
darker green lines, and the umbonal folds are usually more 
wavy than usual. The surface, which in the adult is 
smooth, is rather coarsely wrinkled in the fry, where (as 
is the case with most Anodons) the elevation of the dorsal 
margin is pre-eminently remarkable. 

The variety rostrata (Anod. rostrata, Zincu. in Ross- 
masl. Iconog. pt. 4, pl. 20, f. 284, and pt. 11, pl. 54, 
f. 737.—A. cygnea, var. rostrata, Brown, Il. Conch. G. B. 
p- 81), is not very common, and may easily be recognized 
by its strongly marked characters. It is elongated, more or 


160 UNIONIDA. 


less compressed, rounded both above and below at the very 
short anterior extremity, and produced posteriorly into a long 
rostrum, whose subtruncated tip is generally rounded off. 
Its dorsal line is arcuated, and slopes downwards in front ; 
behind it sometimes rises, sometimes falls, and the upper 
posterior edge is occasionally retuse, occasionally a little 
convex: the ventral edge is straightish or incurved. The 
epidermis seems almost always of a brownish or dusky 
olive-colour, and this is likewise the case with Avonensis 
(Mytilus A vonensis, Monv. Test. Brit. p. 172.—Torr. Conch. 
Diction. p. 116.—Index Testaceolog, pl. 12, f. 34.—Mytilus 
anatinus, var. Avonensis, Maron and Rack. Linn. Trans. 
vol. vii. pl. 3a. f. 4. Mytilus incrassatus, Suzpparp, Trans. 
Linn. Soe. vol. xii. pl. 5, f. 4. — Anodon Avonensis, Turr. 
Dithyra Brit. p. 241.— Anodon cygneus var. Avonensis, 
Brown, Ill. Conch. G. B. pl. 29, f. 2), which is of a some- 
what oval shape, rounded at both ends, short, and narrower 
in front, where the dorsal edge manifestly declines, and 
neither distinctly winged nor beaked behind, where the 
dorsal line is generally a little arched, and the upper pos- 
terior margin a little convex. The connection between 
this and the preceding is very close, the absence of the 
rostrum almost constituting the sole difference. 

The limits of our work forbid the specification of the less 
striking variations. Dusky and solid examples, which 
bear some resemblance to the last in colouring, and the fall 
of the front dorsal edge, but are more rhomboidal and sub- 
rostrated, are usually termed ponderosa (Myt. cygneus var. 
Maron and Rack. Linn. Trans. vol. vii. pl. 3 a. f. 3.— 
Ross. Iconog. Land und Siissw. Moll. pt. 4, pl. 20, f. 282. 
—Anodonta ponderosa, Preir. Deutsch. Land und Siissw. 
Moll. pt. 2, pl. 4.—Kuickx, Moll. Brab. Austr. p. 81): the 
paludosa of Turton is beautifully radiated with light yel- 


ANODONTA. 161 


lowish interrupted lines, on a ground of clear bluish-green, 
(a colouring not confined, however, to that variety,) &c. 

Some of our larger examples measure six inches in 
length, and about three in breadth. We need not specify 
any peculiar localities for a species so universally diffused 
throughout Europe, but may observe that some of the 
more beautifully painted shells are obtained in the docks 
of London, and several of the more remarkable forms in the 
river Lea, near the metropolis. 

The animal is shaped like the shell; the margins of the 
mantle are quite plain in front, fringed with two rows of 
short cirrhi, the outer range more closely set than the mner, 
at its branchial portion, plain again and projecting in tube- 
like fashion at its anal. The posterior part of the mantle 
is tawny brown, mottled, slightly edged with white anally, 
the frontal and anterior portions yellowish, as is also 
the large, broad foot. The viscera are pale. The outer 
lamina of the mantle, according to Trdschel, forms the 
mantle; the imner one is quite free from the foot. The 
outer one is the lodging-place of the young in spring and 
summer. The labial palps are broadly triangular and par- 
tially united. 

This variable mollusk is generally distributed through 
pools, slow streams, and canals in England, Ireland, and 
Scotland. It is said to be a favourite food of aquatic 
birds. Abroad it extends its range all over Kurope. 


VOL. II. Yj 


162 


MYTILID. 


Tue true Mussels are mostly inhabitants of the sea, a 
few only dwelling in fresh water. They have more or less 
elongated and very inequilateral shells, always, however, 
equivalve. The hinge is of a very simple structure, gene- 
rally devoid of teeth ; the ligament is linear. The surface 
of the shell is smooth, or rugose, or obliquely striated and 
sulcated, and is often covered by an epidermis. The animal 
has always two adductor muscles and a narrow strap-shaped 
foot, furnished with a byssal groove. It can spin a very 
strong and copious byssus, though, as in the case of the 
Lithodomi, this is in some species only done when it is 
young. The mantle has its edges variously united in some 
genera, and apart in others, so that some forms have distinct 
siphonal tubes and others none. Usually the anal tube is 
complete, and the branchial only rudimentary. 

The structure of the shell in the J/ytilide has been sub- 
mitted to microscopic examination by Dr. Carpenter, with 
interesting results. He finds the shells of Mytilus, Modiola 
and Lithodomus all to possess a periostracum of horny 
membrane in which no distinct structure could be detected. 
Between it and the shells a thin layer of minute cells may 
frequently be observed. The shell itself presents two layers, 
distinguishable by their colour; the internal one is often 
iridescent and always nacreous. Neither layer in the two 
former genera presents very distinct organic structure, but 


MYTILIDA. 163 


in Lithodomus the external stratum has a remarkable 
tubular structure, resembling that of dentine. The shell of 
Dreissena has a very different organization. In it the in- 
ternal layer is composed of large prismatic cells. Between 
the internal white layer and the periostracum is a layer 
of a brownish colour, in which also traces of a cellular 
structure present themselves; especially in a section made 
perpendicularly to its surface, which brings into view a de- 
cided prismatic arrangement.* Such marked differences of 
minute structure in genera so very closely and unquestion- 
ably allied, leads us to infer that they afford but feeble 
indications of the true position or rank of a species or group 
in the series, though probably important as indications of 
the special adaptation of the creature under examination to 
peculiar conditions. 

In the oldest fossiliferous rocks yet explored we find the 
remains of bivalve shells presenting striking resemblances, 
and indicating close affinities to the Mytilide now existing. 
As, however, in the latter, form of shell affords but a feeble 
clue to the distinctions which separate genera, it is by no 
means improbable that several groups of generic value, 
long since become extinct, may have existed in ancient 
epochs, though the shapes of their shelly envelopes are so 
very similar. 


DREISSENA. VAN BENEDEN. 


Shell equivalve, very inequilateral, sub-triangular, 
tumid, surface covered with an epidermis, beaks terminal, 
furnished internally with a transverse shelf or partition. 
Hinge composed of an imperfectly developed cardinal tooth 
in the right valve, and a corresponding socket in the left : 


* Brit. Assoc. Report. 1847. 


164 MYTILIDA. 


ligament linear, internal. Three muscular impressions. 
Pallial impression obscure. 

Animal oblong, its mantle closed except a passage for 
the foot and the two siphonal orifices. Branchial opening 
prolonged into a tube with a circular fringed orifice ; anal 
opening plain and subsessile. Foot short, ligulate, with a 
conspicuous byssal groove. 

This small group of Myzilide is important as constituting 
a link between that family and the Unionidae, and like the 
latter inhabits fresh water. It was founded by Van Bene- 
den in 1835, for the Mytilus polymorphus of Pallas, and in 
the “‘ Annales des Sciences Naturelles” for that year, the 
Belgian naturalist has published a very excellent and de- 
tailed monograph upon it, including an anatomy of the 
animal, the peculiar features of which warrant a separation 
from Mytilus, not clearly indicated by the shell. As long 
ago as 1824, Mr J. de C. Sowerby called attention to 
characters, and in 1826 the arrangement of the mantle and 
siphons was noticed by Von Bar, in Oken’s “Isis.” In 
the same year with Van Beneden the genus Tichogonia 
was constituted for it, as a shell only however, by Ross- 
missler. Its claims to a generic rank were remarked by 
Gray in 1825. There are several species both recent and 
fossil. The living ones have a wide dispersion, and geolo- 
gically the genus dates as far back as the epoch of the 
Wealden. 

The fossil genera Congeria and Knocephalus appear to 
be identical with Dreissena. A number of extinct species 
are recorded from tertiary strata of the parent region of the 


species we have to describe. 


DREISSENA. 165 


D. potymorena, Pallas. 


Plate XLII. fig. 4, 5, and (Animal) plate Q, fig. 4. 


Mytilus polymorphus, Pauuas, It. Russ. vol. i. p. 478.— Scurorer, LHinleit. 
Conch. vol. ili. p. 471.—GMeE.iy, Syst. Nat. p. 3363.— 
J. Sowrersy, Trans. Linn. Soc. yol. xiv. p. 585; 
Zoolog. Journ. vol. i. p. 584.—FErRussac, Bull. Sciences 
Nat. 1826, p. 142.— Index Testaceolog. Suppl. pl. 2, 
Mytilus, f. 6. —Sowxrsy, Genera of Shells, Mytilus, 
f, 4,.—Dusuayes, Lam. Anim. s. Vert. (ed. Desh.) vol. 
vii. p» 50. — ReEve, Conch. Systemat. vol. i. pl. 102, 
f. 4.—H Ant. Recent Shells, vol. i. p. 250, Suppl. pl. 2, 
Myt. f. 6. 
Mytilus e flwwio Volga, CHEMN. Conch, Cab. vol. xi. p. 256, pl. 205, f. 2028. 
» 2 Volgensis, GRAY, Annals Philosoph. 1825, p. 139. 
»»  lineatus, HAARDENBURG, Commentatio de H. N. Molluscorum Belgi- 
corum (fide de Haan, Van Beneden, &c.) 
»,  Hageni, Barr, ad instaurat. solemnium adjecta Mytili novi descriptio 
(Keeningsb. 1825); Oken’s Isis, 1826, pt. 5, p. 525 (fide 
Van Beneden). 
» Arca, Kickx, Desc. nouy. espéce de Moule. 1834. 
Dreissena polymorpha, VAN BENEDEN, Annales de Sc. Nat. 1835, p. 210, pl. 8, 
f. 1 to 11.—SrrickLtanp, Mag. Nat. H. 1838, p. 361. 
— Gray, Manual L. and F. W. Shells, p. 300.—Brown, 
Illust. Conch. G. B. p. 76, pl. 29, f. 4 to 9. 
Tichogonia Chemnitzii, RossMAsst. Iconog. Land and Siissw. Moll. p. 113, pl. 3, 
f, 69. 


There is no fear of this naturalized bivalve being con- 
founded with any other shell at present discovered in our 
Islands. Its peculiar painting separates it from any 
species to which it is the least allied in form. This 
painting consists of chocolate-coloured flexuous or zigzag 
markings, arranged in a concentric direction upon a white 
ground, which are chiefly displayed in the younger indi- 
viduals, and towards the beaks of the elder examples, and 
usually become more scanty in number, and less beautifully 
undulating, as they approach the hinder termination, and 
are entirely absent, in every stage of growth, from the 


166 MYTILIDA. 


basal area. This portion, which, as well as the remainder 
of the surface, is covered with a glossy, olivaceous, ash- 
coloured epidermis, exhibiting a more yellow complexion 
upon the umbones, and in the immature specimens, is desti- 
tute of markings, and so abruptly compressed that its 
upper edge is distinctly angulated. Along that line the 
valves, which may be termed cuneiform in convexity, are 
extremely ventricose, but rapidly diminish above it. 
Generally speaking, the basal portion is flat or concave, 
and its outline is usually incurved, particularly near the 
beaks, which are extremely acute, bent down a little, 
almost touching, and usually decorticated. The texture is 
opaque and rather strong; the byssal aperture is of an 
elongated or lanceolate form, and the sinus for it, is usually 
more profound in the margin of one valve than in the 
other. The general shape is that of the common mussel, 
and liable to the same modification in its proportions : we 
have not, as yet, however, seen any individuals, which re- 
semble the broad variety of that shell, and the basal part 
of the hinder extremity seems always the most projecting, 
since typically the upper or posterior edge sweeps to the 
base in one arcuated and much declining curve. The 
cardinal edge is short, occupying only one-fifth of the out- 
line. The interior, which is of a milk or porcelain white, 
and not distinctly iridescent, often displays the external 
markings: the lamina, which connects the two sides of the 
shell at the beaks is rather deep set, smooth on the sur- 
face, and rather strong: there seems an obscure apical 
elevation of the margin in the right valve, and a corre- 
sponding sinus in the left. 

Individuals whose length is an inch and three-quarters, 
and whose breadth is one inch, may be regarded as remark- 
ably fine. The epidermis is often much wrinkled behind ; 


DREISSENA. 167 


and the coloured markings would appear from Captain 
Brown’s figures to be occasionally obsolete. That gentle- 
man observes, that the scars in his specimens were of a 
purple hue; this, however, is not the case in our ex- 
amples. 

The animal has the mantle closed in front, except a 
small opening, from whence the short ligulate, or subey- 
lindrical foot can be protruded, when it desires to fix its 
byssus. This portion of the mantle is white, and the mar- 
gins of the orifice are simple. At the posterior or wide 
extremity, the mantle becomes of a yellowish or fawn 
colour, striped in a zebra-like manner with dark brown or 
purple ; it is there prolonged into a cylindrical tube, with 
a circular orifice, which is bordered and internally fringed 
by short rather stout pointed cirrhi. Above this dorsally, 
at a little distance, is the slightly projecting and much 
smaller anal orifice, similarly coloured, but not fringed. 
The animal pouts out both orifices freely in confinement. 
The foot is white, except its byssiferous grooved portion, 
which is of a pale yellow colour. The lips are rather large, 
triangular, and lanceolate. 

These mussels live gregarious, often attached in great 
numbers to each other, in fresh and brackish waters. 
Originally, apparently, inhabitants of the rivers around the 
Black Sea, they have gradually extended their range all 
over Kurope; capable of enduring salt-water for a time, 
they have, probably, been carried across seas on the 
bottoms of ships, and in this manner have reached Eng- 
land and become so common in our canals, as to be much 
more abundant than many of our indigenous mollusks, Its 
history, as a British species, dates from 1824, when Mr. 
J. de Carle Sowerby exhibited it to the Linnean Society, 
stating that it was found “in abundance, attached to shells 


168 MYTILIDZ. 


and timber, in the Commercial Docks, by James Bryant, 
Esq., who used the animal as bait for perch.” Mr. Stark 
found it in the Union Canal, near Edinburgh, in 1834, and 
the Rev. M. J. Berkeley observed it in the Nen, in 1836, 
In the latter case, the discoverer believed it had been 
introduced from Wisbeach on timber, in 1828. Thus, it 
would appear to have found its way into Britain, at several 
points, and is now common in the canals of the Midland 
and Northern counties. 

On the Continent it is found in the Wolga, Danube, 
Elbe, and many of the rivers of Germany and Belgium. 
It occurs in both the Caspian and Black Seas, and fossil in 
Transylvania. It is, probably, a species of ancient origin, 
and one of the members of the old Aralo-Caspian fauna. 


MYTILUS. Linnzus. 


Shell equivalve, very inequilateral, subtriangular, more 
or less tumid, surface covered with an epidermis ; beaks 
terminal. Hinge without true teeth, though often more 
or less denticulated ; ligament linear internal ; two unequal 
muscular impressions, pallial impression obscure, simple. 

Animal oblong, its mantle freely open in the branchial 
and ventral region ; ventral margin simple, branchial fur- 
nished with pinnated fringes; anal opening plain and 
sessile; adductor muscles unequal; foot narrow, ligulate, 
furnished with a byssal groove. 

This genus and the next come so near each other, that 
many malacologists of repute have given up the idea of 
drawing a line between them. Until, however, we find 
that the very important difference between them in the 
construction of the branchial region of the mantle be proved 


a specific and not a generic distinction, we feel bound to 


MYTILUS. 169 


retain both Mytilus and Modiola. As a general rule, the 
species of the former genus are littoral, those of the latter 
inhabitants of moderately deep water. Mytili are found in 
all seas, and range, though obscurely, far back in time. 

In all countries the species of this genus are sought after 
for food, and accounted among the most savoury of shell-fish. 
They are eaten either raw, boiled or roasted. Every now 
and then some unfortunate Mytilophagist is first, and the 
newspaper-reading public afterwards, thrown into convul- 
sions through some deleterious quality which neither boil- 
ing nor roasting can dissipate. The person affected is said 
to be musseled, and exhibits all the symptoms of poisoning. 
Chemistry and anatomy have alike failed in detecting a 
cause ; and neither the season of the year, nor the mode of 
cooking, nor the freshness or staleness of the shell-fish,—to 
all which supposed causes the symptoms have been attri- 
buted—prove on close inquiry to have any connection with 
the results. The subject has been investigated by Dr. 
Burrows,* who states that commonly “the local effects 
have been trifling, and the prominent symptoms have been 
almost entirely indirect, and chiefly nervous.” Sometimes 
an eruptive disease, resembling nettle-rash, and accompanied 
with violent asthma comes on; sometimes a comatose or 
paralytic disorder, numbness about the mouth, gradually 
extending to the arms, with great debility of the limbs, 
difficulty of swallowing and speaking. Fatal cases have 
generally exhibited epileptic symptoms or delirium, con- 
vulsions, and coma. Emetics rapid in their action, have 
been of use in treatment; ether relieves the difficulty of 
breathing and the other nervous symptoms, and Epsom salts, 
acidulated with dilute sulphuric acid, in small and frequent 
doses, removes the nettle-rash. 


* London Medical Repository, vol. ili. p. 445. 
VOL, Il. Z 


170 MYTILIDA. 


M. epuuis, Linneus. 


Plate XLVIII. fig. 1 to 4, and (Animal) plate Q. fig. 5. 


Lister, Anim. Angl. pl. 4, f. 8.—Regenfuss, Choix Coquil. pl. 4, 
f. 47; pl. 7, f. 8; pl. 11, f. 58.—Knorr, Délices des Yeux, pt. 
Osiplemlos tana 
Mytilus edulis, Linn. Syst. Nat. ed. 12, p- 1157 ; Fauna Suecica, ed. 2, p. 521. 
PENNANT, Brit. Zool. ed. 4, p. 110, pl. 63, f. 73.—PULTENEY, 
Hutchins’ Hist. Dorset, p. 38.—Donovan, Brit. Shells. vol. iv. 
pl. 121, f. 1.— Monr. Test. Brit. p. 159. — Mar. and Rack. 
Linn. Trans. vol. viii. p. 1065,— Rackerr, Dorset Catalog. p. 
39, pl. 12, f. 5, left hand. — Turr. Conch. Diction. p. 109; 
Dithyra Brit. p. 19° —F.em. Brit. Anim. p. 411.—Macertriv. 
Moll. Aberd. p. 234.—Brit. Marine Conch. p. 109.—Brown, 
Ilust. Conch. G. B. p. 76, pl. 27, f. 11 to 15, and pl. 45, f. 4, 
5, 6, 7.— AupER, Cat. Moll. Northumb. and Durh. p. 80. — 
Fasric. Fauna Groenland. p. 417. — Born. Mus. Ces. Vind. 
p- 126.— Cuemn. Conch. Cab. yol. viii. p. 755, pl. 84, f. 750, 
751, 755. — Pout, Test. Sicil. vol. i. pl. 1, f. 13, and vol. ii. p. 
194, pl. 31 (except f. 1).—Burrows, Elem. Conch. pl. 10, f. 5, 
Dittw. Recent Shells, vol. i. p. 309. — Lamarck, Anim. s. 
Vert, (ed. Desh.) vol. vii. p. 47.—GouxLp, Invert. Massach. p. 
p- 121, f. 82. — Penny Cyclop. vol. xvi. p. 46, f. a. b. and 
p. 47, fig. a. b. c. (well).—Hant. Recent Shells, vol. i. p. 250, 
pl. 12, f. 22, 48, and Suppl. pl. 2, Mytil. f, 2.—Puutripepi, Moll. 
Sicil. vol. ii. p. 53. 
»  ungulatus,* LINN. (not GEL. nor Lam.) Syst, Nat. ed. 10, p. 705; ed. 
12, p. 1156 (partly).— Donoy. Brit. Shells, vol. iy. pl. 
128, f. 2.—Turr. Dithyra Brit. p. 195. 
Common mussel, DA Costa, Elements Conch. pl. 6, f. 3. 
Mytilus pellucidus, PENN. Brit. Zool. ed. 4,-vol. iv. p. 112, pl. 63, f. 75.—Donoy. 
Brit. Shells, vol, iii. pl. 81. — Monv. Test. Brit. p. 160.— 
Mar. and Rack. Linn. Trans. vol. vii. p. 107.—LaAskery, 
Mem. Wern. Soc. vol. i. p. 392.—Turt. Conch. Diction. 
p. 110; Dithyra Brit. p. 197, pl. 15, f. 1, 2; Brit. Marine 
Conch. p. 110, f. 105.— Ditiw. Recent Shells, vol. i. p. 


* Montagu’s description of M/. wngulinus is avowedly compiled from foreign 
authors, and comprises M/. achatinus, &c.; from it, again, is borrowed the 


diagnosis of the M. wngulatus in Turton’s “ Conchological Dictionary” (p. 111). 


We have not seen a specimen quite so large as that delineated by Chemnitz, but 
have little doubt that his type (Conch. Cab. vol. viii. p. 176, pl. 84, f. 756) was 
a large variety of edulis. 


{ Deen 


MYTILUS. LG 


309. — Index Testaceolog. pl. 12, f. 22. — Mawes, Con- 
chology, pl. 16, f. 2. 

Mytilus incurvatus, PENN. Brit. Zool. ed. 4, vol. iv. p. 111, pl. 64, f. 74.— 
Mont. Test. Brit. p. 160.—Mar. and Rack. Linn. Trans. 
vol. viii. p. 105, pl. 3, f. 7. — Laskey, Mem. Wern. Soc. 
vol. i. p. 391. — Tort. Conch. Diction, p. 109; Dithyra 
Brit. p. 197.—Index Testaceolog, pl. 12, f. 48. 

», vulgaris, Da Cosa, Brit. Conch. p. 216, pl. 15. f. 5 (on the left). 

Perna ungulina, Rervzius, Nov. Test. Genera, p. 21. 

Mytilus flavus, Pout, Test. Sicil. vol. ii. p. 207, pl. 32, f. 4. 

»  sagittatus, Pot, Test. Sicil. vol. ii. p. 208, pl. 32, f. 2, 3. 
»  galloprovincialis, LAMARcK, Anim. s. Vert. (ed. Desh.) vol. vii. p. 46. 
— Puitirr1, Moll. Sicil. vol. i. p. 72, pl. 5, f. 12, 
13; vol. ii. p. 53. — Hanu. Recent Shells, vol. Hen De 
249. 
»  abbreviatus, LAMARCK, Anim, s. Vert. (ed. Desh.) vol. vii. p. 47.— 
Porrez and Micu. Galerie Douai, vol. ii. pl. 54, f. 1. 
»  retusus, LAMARCK, Anim. s. Vert. (ed. Desh.) vol. vii. p. 48. 
hesperianus, LAMarcK, Anim. s. Vert. (ed. Desh.) vol. vii. p. 48 (pro- 
bably). — Payraup. Cat. Moll. Corse, p. 68, pl. 2, f. 5 
(probably). 
»  dilatatus, Gray, Annals Philos. 1825; Index Testaceol. Suppl. pl. 2, 
Mytil. f. 2. 
»  subsaxatilis, WILLIAMSON, Mag. Nat. Hist. vol. vii. p. 353. — Coucu, 
Cornish Fauna, pt. 2, p. 34.—Brit. Marine Conch. p. 109. 


The extreme variation of contour to which this species is 
liable, has caused its varieties to be designated by several 
appellations. Certain characters, however, pervade them 
all, among which the absence of true teeth may be regarded 
as one of the most essential importance. 

That which we regard as the typical form, meaning 
thereby the shape which is naturally assumed by a species 
not forced to adapt its proportions to the circumstance of 
its habitat, is not what we are accustomed to view it in the 
stalls -of the fishmongers, narrow and subarcuated, but 
rather the dilated and triangular subsawatilis, whose soli- 
tary haunts permit a freer development of its several parts, 
than the gregarious habits of the more frequent variety 
allow of. In this, then, the form is shorter and subtrigonal, 


172 MYTILIDA. 


with the dorsal angulation much more marked, and the 
hinder termination more expanded than in the ordinary 
cramped variety. In the latter, the cardinal edge is short, 
and the posterior produced comparatively straight, and 
running parallel to the ventral ; in the former the hinder out- 
line arches out more boldly both above and below, and the 
greater declination of the posterior edge renders the pro- 
jection of the dorsal angle more apparent. This angle, 
which is either subcentral or lies rather before the middle 
of the shell, is greatly modified in the extent of its obtuse- 
ness by the greater or lesser curvature of the upper or pos- 
terior margin, and the degree of its declination. If the 
angle formed by the junction then of the upper and cardinal 
edges be a very obtuse one, the former will run nearly pa- 
rallel to the basal, and instead of uniting with it in a single 
sweep, generally forms a second very obscure rounded-off 
corner, as it merges into the posterior extremity, which is 
usually rather broadly rounded, and more projecting below 
than above. The basal or front ventral margin, is by no 
means constant in its outline ; occasionally as in the variety 
incurcatus, it is profoundly concave, in others it is almost 
straight ; in some it is slightly gibbous behind, in others it 
swells out more towards the beaks. 

There are two principal variations of colour. That which 
is the most common is where the shell, whose texture is 
strong and nearly opaque, has the exterior, beneath the 
olivaceous or yellowish-brown epidermis, of an uniform 
blackish-blue, (the colouring matter in its earlier coats is 
almost always arranged in darker rays upon a paler ground, 
and in darker and lighter zones, as may be observed where 
the surface is abraded); the basal portion, however, is often 
of a squalid white; the interior is of a more or less dull 
white, margined with blue. The other, which is a far 


MYTILUS. 173 


more beautiful thin and semi-transparent shell, has a 
brownish-yellow epidermis, beneath which the surface is 
either uniform white, which is very rarely the case, or 
adorned with a very variable number of narrow and occa- 
sionally even linear blue rays on a pale ground; the in- 
terior is of an uniform somewhat nacreous white, but never 
opaline. 

The entire shell is devoid of sculpture; the epidermis is 
more or less glossy, rarely if ever either quite dull, although 
generally but little shining or highly polished. The com- 
pressed basal area is usually narrow, and generally termi- 
nates rather abruptly behind. The beaks are pointed, 
quite terminal, and diverge a little from each other. The 
hinge-margin is not crenulated (a ready mark of distine- 
tion from the minimus of Poli and Philippi, which looks 
like a dwarf specimen of it); there are no real teeth, but 
about four narrow denticles, usually concealed by the over- 
lapping epidermis. 

Ordinary sized English specimens do not much exceed 
two inches and a half in length, and about half that 
breadth. Mr. Barlee, however, has an example from Loch 
Fyne which measures eight inches and a half! 

The Mytilus striatus of the English writers (Mont. Test. 
Brit. p. 173.—Trans. Linn. Soc. vol. viii. p. 112) solely 
constructed from a figure (75) in Walker’s “ Testacea 
Minuta Rariora,” and surmised by Montagu to be possibly, 
if indeed a shell at all (which we much doubt), the fry of 
the large Modiola, is cited by Turton for the young of this 
species. 

Animal shaped as the shell, thick, the margins of the 
mantle freely open in front and in the branchial region, 
united to form a tube only in the anal region. They are 
quite simple anteriorly near the beaks, serrated towards 


174 MYTILID A. 


the middle of the front of the shell, and furnished with 
pinnated cirrhi in the branchial range. There are about 
sixteen of these pinnated fringes which are usually, in 
British specimens, of a yellowish white colour, though 
sometimes, as well as the edges of the mantle, tinged with 
brown, and in the foreign variety galloprovincialis they 
are often deeply tinged with purple. The anal siphon is 
very short, white, and equals half the breadth of the 
branchial range; its margins are quite plain. The foot is 
dusky, narrow, strap-shaped and grooved; from the basal 
part of the groove the animal spins its byssus, which 
is long, coarse, and of a yellowish brown colour. When 
the byssus is broken away, another set of threads is readily 
and often rapidly spun. The branchial leaflets are tawny, 
elongated, nearly equal, and free at their lower edges. The 
labial palps are also tawny, and of a triangular acuminate 
shape, smooth on their outsides, and (as first observed by 
Mr. Clark,) only ‘partially pectinated on their inner sur- 
faces. 


The common mussel is much used in many places for 
food, and still more for bait. Dr. Knapp of Edinburgh 
has communicated to us a very interesting account of the 
quantities of this animal destroyed annually in the neigh- 
bourhood of that city. ‘‘ As an article of food,” he states, 
‘there cannot be used fewer than ten bushels per week in 
Edinburgh and Leith, say for forty weeks in the year, in 
all 400 bushels annually. Each bushel of mussels when 
shelled and freed from all refuse, will probably contain 
from three to four pints of the animals, or about 900 or 
1000, according to their size. Taking the latter number, 
there will be consumed in Edinburgh and Leith about 
400,000 mussels. This is a mere trifle compared to the 
enormous number used as bait for all sorts of fish, especially 


is ee ee 


MYTILUS. 175 


haddocks, cod, ling, holibut, plaice, skate, whiting, &e. 
In Newhaven alone there are four large deep-sea fishing 
boats, which generally go out three times a week, and fish 
for about thirty weeks in the year, excluding Sundays and 
bad weather. Each of these large boats carries eight men, 
with eight lines of 800 yards in length, which, at a low 
calculation, take 1200 mussels to bait, each time they are 
used ; so that each large boat will use 28,800 mussels per 
week, equal to 864,000 per annum. But there are about 
sixteen other smaller boats, which go out daily, or rather 
at twelve o’clock every night for about the same number of 
weeks in the year. Hach carries four men, with four lines 
800 yards long. Their consumption of mussels will come 
to 3,456,000. The total consumption of mussels for bait 
annually in Newhaven alone may be reckoned at 4,320,000. 
As there are nearly as many used at Musselburgh and 
Fisherrow, Buckhaven, Elie, Anstruther, Pittenweem, 
Crail, and other places on the Frith of Forth, we may 
calculate that thirty or forty millions of mussels are used 
for bait alone by the fishermen of this district each year. 
Numbers come from the river Eden in Fife, and are sold at 
25s. per cask. The best mussels at Newhaven are got 
directly north of the Pier, in three fathoms water, and are 
sold at 8d. per basket, each containing nearly a bushel.” 
The beds are private property, and some of them having 
been injudiciously or avariciously exhausted, the number of 
mussels in the Forth has decreased, and the price increased 
with the last ten years. 

Mussels are kept in many places in artificial beds, to be 
used when required for bait. At Anstruther, in Fifeshire, we 
have seen these ‘“‘ mussel gardens,” as they are called,—little 
plots of sea-shore between tide-marks, edged in by stones, and 
held as private property. In Northumberland, Mr. Alder 


176 MYTILIDA. 


states, the fishermen built up piles of stones among the 
rocks to keep their mussels safe. 

We have alluded to the pearls procured from this species 
when treating of the Unio margaritiferus.* They are com- 
monly small, ill-coloured, and of little value, yet have been 
at various times much sought for. The following passage in 
Camden+ about the pearls in Cumberland, evidently refers 
to these. ‘ Higher up the little river that runs into the 
sea, in which the shell-fish having by a kind of irregular 
motion taken in the dew, which they are extremely fond 
of, are impregnated and produce pearls, or to use the poet’s 
phrase, bacce cochlea, shell berries, which the inhabitants, 
when the tide is out, search for, and our jewellers buy of 
the poor for a trifle, and sell again at a very great price.” 
A very curious account of a recent pearl fishery in North 
Wales is given by a correspondent in Loudon’s Magazine 
of Natural History, for 1830. The writer has confounded 
the Mytilus edulis with the Unio. To the latter his re- 
mark on pearls ‘found up the river” only applies. We 
quote the letter nearly entire :— 

‘‘The pearl mussel is found in abundance in the river 
Conway, in North Wales, and is collected by many of the 
natives, who obtain their livelihood entirely by their in- 
dustry in procuring the pearls. When the tide is out they 
go in several boats to the bar at the mouth of the river, 
with their sacks, and gather as many shells as they can 
before the return of the tide. The mussels are then put 
into a large kettle over a fire to be opened, and the fish 


* Since our account of that shell was printed, Dr. Knapp has communicated 
information respecting the pearls found in it in Scotland. He says, “ they are 
now rare, the price of fine ‘pearls of good lustre and water varying from two 
shillings to ten or twelve pounds, according to size. Round pearls, perfect in 
every respect, about the size of a pea, are worth three or four pounds.” 

+ Camden’s Britannia, Gough’s edition, vol. ili. p. 189. 


MYTILUS. 177 


taken out singly from the shells with the fingers and put 
into a tub, into which one of the fishers goes barefooted, 
and stamps upon them until they are reduced into a sort of 
pulp. They next pour in water to separate the fishy sub- 
stance, which they call solach, from the more heavy parts, 
consisting of sand, small pebbles, and the pearls which 
settle at the bottom. After numerous washings, until the 
fishy part is entirely removed, the sediment, if I may so 
term it, is put out to dry, and each pearl separated on a 
large wooden platter, one at a time with a feather; and 
when a sufficient quantity is obtained, they are taken to 
the overseer, who pays the fisher so much an ounce for 
them. The price varies from 1s. 6d. to 4s.; there are a 
number of persons who live by this alone, and where there 
is a small family to gather the shells and pick out the fish, 
it is preferable to any other daily labour. The pearls are 
generally a dirty white, sometimes blue, but never I believe 
green or reddish. I cannot with accuracy say how many 
ounces are taken to the overseer each week, though I might 
say there are some scores. But what makes this fishery 
the more singular is the mystery which hangs over it. At 
present it is a perfect monopoly, and there is but the one 
who buys them up that knows what becomes of them after- 
wards. It has been carried on in this manner for many 
years, and as such a thing, if made public, might prove 
more beneficial to the neighbouring poor, by causing a 
higher price to be given for the pearls, it would be more 
so, if any of your numerous correspondents could throw 
some light on this interesting subject. There have been 
some curious and fanciful surmises, which may not be 
thought worth mentioning. Some suppose that the pearls 
are sent abroad to be manufactured into seed pearls; others 
more gravely, that they are exported to India to be dis- 


VOL. II. A A 


178 MYTILIDZ. 


solved in the sherbet of the nabobs! However, at present 
it is a mystery ; and, notwithstanding the pains taken and 
the expense incurred by some liberal gentlemen in endea- 
vouring to find out the secret, it is as great a mystery as 
ever. The huts which have been erected for the con- 
venience of boiling the fish, are on the extremity of the 
marsh, about a mile north of the town of Conway. The 
pearls are seldom found here much larger than the enclosed 
specimens, though about twelve miles up the river, they 
have been found occasionally as large as a moderate-sized 
pea, and have been sold for a guinea the couple, but they 
are very rarely met with. When I say that the price 
varies from 1s. 6d. to 4s. I do not mean to say that they 
are valued according to their size, for the large and small 
pearls are all sold together; but some years ago they were 
as high as 4s., now they are only 2s. per ounce.” 

There is no occasion to enumerate localities for so com- 
mon a shell as the Mytilus edulis, universally distributed 
around our coasts, and plentiful in favourable localities near 
the edge of low water, and in a fathom or two beyond. 
The variety pellucidus ranges deeper. 

The species ranges all round the coasts of the North 
Atlantic, on both its eastern and western sides, and into 
the Mediterranean. It is found fossil] in the red and mam- 


maliferous crags, and everywhere in pleistocene deposits. 


SPURIOUS. 


M. srwens, Linneus. 


Lister, Hist. Conch. pl, 366, f. 206. 
Mytilus bidens, LinnzZus (not Born nor Diniwyn), Syst. Nat. ed. 12, p. 115. 
—Desunaves, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 39. 
»  striatulus, ScHROTER, Einleit. Conchylien, vol. iii. p. 449, pl. 9, f. 16.— 
Turton, Magaz. Nat. Hist. vol. vii- p. 350.—Brit. Marine 
Conch. p. 110.—Index Testaceolog. pl. 12, f. 19. 


— 


MYTILUS. 179 


Perna striatula, Rerzius, Noy. Gen. Testac. p. 21. 

Mytilus exustus, (not Born, GMELIN, Ditpwyn), Lamarck, Anim, s. Vert. (ed. 
Desh.) vol. vii. p. 39. — Brit. Marine Conch. f. 22.— Dzs- 
HAYES, Encyclop. Méthod. Vers. (Supplement), yol. i. 
p, 559.— Han ey, Recent Shells, vol. i. p. 244. 

Encyclopédie Méthod. Vers. pl. 220, f. 2 (2), 3, 4. 


Dr. Turton has introduced this W. Indian mussel among our 
British bivalves, on account of Mr. Bean having taken it alive 
from some floating timber at Scarborough. That gentleman, 
however (to whom we are indebted for specimens), confesses, with 
his usual frankness, that he has only obtained it under circum- 
stances which leave no doubt upon his mind of its exotic origin. 
Our synonymy demands a few explanatory remarks. One of the 
results of our long and studious examination of the Linnean 
cabinet is the confirmation of M. Deshayes’ conjecture of the iden- 
tity of the Mytilus exustus of Lamarck with the lost bidens of 
Linnzeus. The language and drawing of Schroeter leave little 
doubt that the striatulus of his work is the same species, but the 
original shell so named in the “ Mantissa” of Linnzus, (p. 548. 
—Dillw. Recent Shells, vol. i. p. 308.) stated to be grey, pellucid, 
most delicately striated, and from the Northern Ocean, will not 
so exactly agree as is fitting for its identification. We have re- 
ceived from the United States of N. America examples of this 
bivalve (whose range of variation is so extensive, that we have 
thought it advisable, for its full recognition, to aid our references 
by a short description), as the J. cubitus of Say, but that 
author’s language (Journ. Acad. Nat. Scien. Philadelphia, vol. 
il. pt. 11, p. 263.) seems, at least, equally applicable to Modiola 
sulcata, a representation of which in Lister (pl. 365), he remarks, 
it agrees very well with, and repudiates the figures of the La- 
marckian exustus, in the “Encyclopédie Methodique.” Our 
recollection of the types of the 7. ustulatus of Lamarck (as usual, 
inadequately characterized), tends to the supposition that they 
were not specifically distinct ; but we will not venture to offer 
any positive assertion to that effect, The J/ytili demand a close 
inspection of the growth-line, as indicative of the natural con- 
tour, being all of them individually affected as to the incurva- 
tion or gibbosity of the front ventral margin, the extent of dor- 
sal angulation, and even the arcuation or retusion of the pos- 


180 MYTILIDA. 


terior outline, by the freedom or crampedness of their dwelling- 
places. 

The shell is covered with a thin brownish yellow or scorched 
looking epidermis (with a lustre more or less resinous), beneath 
which the surface is concentrically painted with more or less 
interrupted bands of a sombre violet or dusky liver-colour on 
a paler ground. These markings are occasionally obsolete, and 
sometimes partially transmuted into flexuous radiating streaks. 
The interior is rich purple, or pearly white with purple stains. 
The exterior is sculptured with most numerous radiating strie, 
which are elevated, subcrenated, slightly divergent, and of nearly 
equal strength throughout, except that they attenuate a little 
in front, and usually become obsolete near the byssal aperture. 
The interstices are about the width of the costellar striz, and 
are restrained from dilating by the continual bifurcation of the 
latter. The beaks are not perfectly terminal. The hinge has one 
or two small teeth in each valve. The margin is crenated, 
except near the byssal gape. 

The general shape is very irregular ; typically it is subtri- 
angular, with the dorsal edge straightish, much elevated, and 
nearly equal in length to the distance to the hinder extremity, 
the subcentral dorsal angulation being well marked ; occasionally 
it is crescent-shaped, the dorsal edge being curved and uniting 
to the posterior margin without angulation. The convexity is 
usually moderate ; when the valves have free scope for dilation, 
then trifling; when they are contracted and narrow, then con- 
siderable. 


M. crenatus, Lamarck. 


Mytilus crenatus, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 39. — W1LLcox, 
Zool. Journ. vol. i. p. 590; Report Brit. Assoc. vol. iii, — 
Brown, Illust. Conch. G. B. p. 77, pl. 23, f. 1, 2. — 
Sowersy, Genera Shells, Mytilus, f. 3. — ReEve, Conch. 
Iconica, pl. 102, f. 3—Han.ey, Recent Shells, vol. i. p. 244. 
Encyclopédie Méthodique, Vers. pl. 217, f- 3. 


An inhabitant of New Zealand, &e. ; introduced by Mr. C. Will- 
cox as naturalized at Portsmouth, having originally come over 
attached to the ‘‘ Wellesley” from Bombay, and thence spread to 
various parts of the harbour. We know of no good description of 
this species (which is most closely allied to Magellanicus), but the 


MODIOLA. 181 


plate in Sowerby’s “Genera,” (used, likewise, for Reeves’ “ Con- 
chologia Systematica,”) very characteristically represents the shell 
which was kindly forwarded to us for examination by Mr, Willcox. 


M. Arricanus, Chemnitz. 


Knorr, Délices des Yeux, pt. 6. pl. 4, f. 1. 
Mytilus Africanus, Canmnitz, Conch, Cab. vol. viii. p- 160, pl. 83, f. 739, 740, 
7Al. 
»  Afer, GMELIN, Syst. Nature, p. 3358.—Lamarck, Anim. s. Vert. (ed. 
Desh.) vol. vii. p. 44..—Hantey, Recent Shells, vol. i. p. 248. 
»  ungulatus, junior, DiLLWYN, Recent Shells, vol. i. p. 310.—Turt. Conch. 
Dict. p. 111.—FLemine, Brit. Anim. p. 411. 
Moule d’ Afrique, BLAINVILLE, Man. Malacol. pl. 64, f. 2. 
Encyclopéd. Méthodique, Vers, pl. 218, f. 1. 


Introduced by Dr. Fleming under the name of M. ungulatus, 
but only as a straggler, adhering to the bottom of vessels from the 
African coast. 


MODIOLA. J.AamMaARcK. 


Shell oblong, equivalve, inequilateral, valves smooth, or 
suleated concentrically, invested with an epidermis, which 
is usually filamentose, especially in young specimens. 
Anterior side very short, beaks rarely quite terminal. 
Hinge margin toothless, or with only a compressed tooth- 
like callus, and rarely corrugated ; ligament linear. Mus- 
cular sears very unequal, pallial impression obscure. 

Animal oblong, margins of mantle in all parts simple, 
closed only to form a short, and more or less perfect tube 
in the anal region. Foot cylindrical, with a more or less 
cylindrical byssal gland at its base. Branchie elongate. 
Labial palps triangular and pointed. 

It is very difficult to draw a line between the shells of 
this genus and those of Mytilus, and were it not for the 
peculiar simple character of the branchial region, the 
mantle contrasting strongly with the fringed and pinnated 


182 MYTILIDA. 


features of the same part in the latter group, we should feel 
inclined to unite them, as many malacologists of eminence 
have done. The Modiole are often handsome shells, and 
of tolerably ample dimensions. They spin a strong byssus, 
and several of the species can construct a sort of enveloping 
nest from it. They live sometimes singly, sometimes gre- 
gariously, in various depths of water, and are sought after 
for bait by fishermen, though usually rejected, on account of 
their too strong scent and flavour, as food. The genus 
dates very far back in time, many palzozoic shells appear- 
ing to belong to it. 


M. Moptoxus, Linnzus. 


Large, not rayed with crimson ; epidermis lustrous, its fila- 
ments entire at the margins; dorsal edge quite equal to the 
upper posterior one ; beaks not quite terminal. 


Plate XLIV, fig. 1, 2. 


Mytilus Modiolus, Linn. Syst. Nat. ed. 12, p. 1158.—Pxnn. Brit. Zool. ed. 4, 

vol. iy. p. 113, pl. 66, f. 77. —Da Costa, Brit. Conch. p. 

219, pl. 15, f. 5 (on the right). — Putrenry, Hutchins, 

Hist. Dorset, p. 38.-— Donoy. Brit. Shells, vol. i. pl. 23. 

—Mont. Test. Brit. p. 163.—Maron and Rack. Trans. 

Linn. Soc. vol. viii. p. 107.—Dorset Catalog. p. 40.— 

Laskey, Mem. Werner. Soc. yol. i. p. 392. — CHEMN. 

Conch. Cab. vol. viii. p. 178 (but not his Tranquebar 

shell, pl. 85, f. 757).— MistiER, Zool. Danie. pl. 53. — 

Dittw. Recent Shells, vol. i. p. 314.—Index Testaceolog. 

pl. 12, f. 31.—Fuemine, Encyclop. Edin. vol. vii. pl. 
203, f. 22. ; 

umbilicatus, PENN. Brit. Zool. ed. 4, vol. iv. p.1]2, pl. 65, f. 76.— 

Donoy. Brit. Shells, vol. ii. pl. 40. — Monr. Test. Brit. 

p. 164, and Suppl. p. 71.— Maron and Rack. Trans. 

Linn. vol. viii. p. 109.—Index Testaceolog. pl. 12, f. 49. 

curtus, PENN. Brit. Zool. ed. 4, vol. iv. p. 112, pl. 64, f. 76 a. 

curvirostratus, DA Costa, Brit. Conch. p. 220. 

barbatus, PuLTENEY (not Linn.), Hutchins, Hist. Dorset. p. 38.— 

Donoy. Brit. Shells. vol. ii. pl. 70.— Monr. Test. Brit. p. 


MODIOLA. 183 


161.—Maron and Rack. Dorset. Catalog. p, 40, pl. 12, f. 5 
(on the right). 
Modiola Papuana, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 18 (partly). — 
Brown, Illust. Conch. G. B. p. 77 (chiefly), pl. 27, f. 1 to 
4,.— Leacu, Zoolog. Miscellany, vol. ii. p. 33.— Say, 
American Conchology, pl. 45. — BrainvittE, Manuel 
Malacologie, pl. 64, f. 3 (probably). 
s Modiolus, Turt. Dithyra Brit. p. 199, pl. 15, f. 3. — Brit. Mar. Conch. 
p- 107. — Gouxp, Invert. Massach. p. 123.— HAN. 
Recent Shells, vol. i. p. 233, pl. 12,f. 31, 49. 
3s vulgaris, FLEMING, Brit. Anim. p. 412. — AtpEr, Catal. Northumb. 
and Durham Moll. p. 81.—Wooparcu, Conchology, ed. 
Os plata ts Os 


Mytilus Papuanus, DesHayes, Encyclopédie Méthod. Vers, vol. ii. p. 564, pl. 
219) 6 1. 
Modiola barbata, Maccitutv. Moll. Aberdeenshire, p. 237. 


This fine Modiola, which surpasses in amplitude any 
known species of its genus, bears but little resemblance, 
when adult, to most of its European congeners, but ap- 
proximates rather to certain of the species ( Philippinarum, 
Australis, &c.), inhabiting the Chinese and Australian seas. 
Its shape is oblong-subtrigonal, or elongated-oblong, and 
excessively inequilateral ; its valves, when fully grown, are 
strong, opaque, and covered with a pitch-brown cuticle, or 
stout adherent epidermis, which is coarsely wrinkled in a 
concentric direction, slightly glossy, and destitute of all 
painting or variation of tint upon its surface. The younger 
shells have their cuticle of a deep yellow, or fulvous cast, 
changing into chestnut in front and towards the hinder 
dorsal area : intermediate gradations are of an uniform fawn 
colour. The profundity of the valves varies greatly, as is 
usual in the genus, at different portions ; the central area, 
or that which runs diagonally from the beaks to the hinder 
termination of the shell, is rather broadly elevated (not 
cearinated) near the umbones, but greatly diminishes in con- 
vexity below. This elevation is preceded by a broad, but 
very shallow, groove-like space, before which, the surface 


184 MYTILIDA. 


again swells out a little, and then diminishes again in front. 
The chief compression is, of course, at the juncture of the 
hinder dorsal edge with the posterior margin, which latter 
being always more or less produced, the dorsal wing, which 
is more or less subangular (the angle being occasionally 
also rounded off), consequently lies just midway between the 
umbones and the rather broad and well rounded termina- 
tion of the hinder side. The cartilage margin, which is not 
bordered by any dull strip of epidermis, as in Metcalfei, is 
nearly rectilinear, but with a tendency to convexity, and 
rises with an ascent sufficient to prevent the upper and 
lower edges being at all parallel ; the upper posterior out- 
line varies from somewhat arcuated to rectilinear, and is 
never incurved or decidedly retuse. Owing to the all but 
terminal position of the beaks, the anterior side is almost 
rudimentary ; it is very narrow, but not attenuated below, 
as in certain Modiole, by any peculiarly oblique rise of the 
ventral margin, but is rounded and about equally project- 
ing above and below: the front dorsal edge is not on the 
same plane with the hinder one, but decidedly below its 
level. The filaments of the epidermidal beard, which is 
chiefly apparent upon the younger shells, are very slender, 
greatly produced, and not serrated on either edge. The 
interior of the shell is whitish, but often slightly tinged with 
lilac, a deep stain of which is generally visible externally 
on removing the cuticle ; the hinge-margin does not exhibit 
any teeth or crenulation, but is thickened at the beaks. 
The largest individuals usually come from the North, and 
average about five inches in length, and rather more than 
two in breadth: a specimen, measuring seven inches in 
length, and three inches and a quarter in breadth, is re- 
corded by Captain Brown to have been caught by a fisher- 
man’s line, near the Bell Rock, on the coast of Forfarshire. 


MODIOLA. 185 


The animal is oblong, soft, and of a mingled dusky and 
bright-red and orange colour, more or less speckled with 
yellowish-white. The mantle, except its edges, is pale and 
whitish. The base of the foot, and its large and conspicu- 
ous byssiferous gland, which appears as if a distinct organ, 
are wrinkled and cylindric; the finger-shaped portion of 
the foot is subconical, smooth and red, and small in propor- 
tion to the size of the body. The branchial lamine are 
tawny. The posterior adductor muscle is conspicuously larger 
than the anterior. The byssus is strong, and of a more or 
less shiny yellowish hue: the extremities of the threads 
are fixed by a small expansion to neighbouring bodies, and 
being usually arranged in several linear series, cause, when 
they are broken away, the appearance of rows of zoophytic 
cells, or peculiar nidi. 

The Horse Mussel, as this fine species is popularly 
called, is so universally distributed around our coast, that 
to quote localities would be superfluous. We have met 
with it in all depths of water between low-water mark and 
sixty fathoms. It is small at great depths, finest in from 
seven to thirty fathoms, and frequents gravelly and muddy 
localities most. In tide-ways it sometimes envelops itself 
by means of its byssus, in a complete nest or investment of 
threads and gravel: this habit we have observed in thirty 
fathoms water, seven miles north of Anglesea (M‘Andrew 
and E. F.). At Rothesay, Mr. Alder informs us, it is 
common just below low-water mark, and is waded for 
by women and children at low tides for food. 

It ranges through the North Atlantic ; but seems to have 
had its origin on the European side, where it is found fossil 


in the mammaliferous crag. 


VOL. Il. BB 


186 MYTILID. 


M. pnasrorina, Philippi. 


Small, never rayed ; epidermis highly polished, its byssal fila- 
ments simple ; dorsal edge much shorter than the upper posterior 
one; hinge-margin with most minute internal corrugations ; 
beaks terminal. 


Plate XLIV. fig. 3. 


Modiola phaseolina, Puitiert, Mol. Sicil. vol. ii. p. 51, pl. 15, f. 14.—JErrreys, 
Ann. Nat. Hist. vol. xix. p. 313. 


From the simple filaments of its byssal garment, this 
recently discovered shell incurs more risk of being con- 
founded with Modiolus than with barbata, although they 
are profusely disposed as in the latter, rather than scantily 
furnished as in the former. There appears to exist a 
considerable diversity of outline in different individuals, 
some more nearly exhibiting the outline of one, some of the 
other of the two species we have mentioned, but all seem 
either devoid of dorsal angulation, or else with their angle 
much nearer to the anterior end than in those species. 
The valves are subventricose; their convexity is rather 
evenly disposed, there being scarcely any dorsal compres- 
sion, and no posterior retusion of surface. The cuticle is 
highly lustrous (which polish pervades its entire extent) 
and is of a brownish-yellow, becoming paler in front of the 
diagonal elevation. The hinder dorsal edge, which is 
straight, ascends considerably, and is shorter than the 
upper posterior outline ; which latter is subarcuated, and 
runs nearly parallel to the ventral margin, in its junction 
with which it forms a broad and rounded termination. The 
ventral margin is swollen behind; the lower front area is 
very small, and does not at all project beyond the terminal 


beaks, so that strictly speaking there is no anterior side. 


MODIOLA. 187 


The interior does not appear in those we have examined 
to be very pearly, but stained behind with liver colour. 

There is a well-marked rib-like callus which strengthens 
the hinge-margin in front just beneath the beaks, at the 
summit of which the hinge-margin appears when very 
highly magnified, to be subdenticulately corrugated as in 
the genus Jridina. There are a few minute marginal 
crenulations also behind the cartilage. 

This interesting species, first published as British by Mr. 
Jeffreys, in 1847, is probably not very uncommon, and has 
been passed over as the young of Modiolus. He had 
observed it in the Hebrides as long ago as 1843. Since 
then it has been taken not unfrequently by Mr. M‘Andrew 
on the west, and by Lieut. Thomas on the north-east 
coasts of Scotland. It had previously been observed in 


Sicily, but only in a fossil state. 


M. ruupa, Lamarck. 


Never large ; always rayed with crimson or violet, smooth ; 
byssal filaments obscure if present ; posterior edges sub-retuse ; 
beaks not quite terminal. 


Plates XLV. fig. 7, XLVIII. fig. 6, and (Animal) plate Q. fig. 6. 


LisrEr, Hist. Conch. pl. 359, f. 198 >—Kworr, Délices des 
Yeux, pt. 4, pl. 15, f. 3 (probably). 
? Mytilus Modiolus, CuEMN. Conch. Cab. vol. viii. pl. 58, f. 758. 
2 Modiola Americana, Lracu, Zoolog. Miscellany, vol. ii. p. 32, pl. 72, f. 1. 
os tulipa, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 19 (partly).— 
Sowrrsy, Genera Shells, Modiola, f. 5 (probably).— Purvipri, 
Moll. Sicil. vol. i. p. 69, and vol. ii. p. 50.—SowxErsy, Conch, 
Manual, f. 160 ?—R«EVvE, Conch. Systemat. vol. i. pl. 101.f. 5 (prob): 
* radiata, Brit. Marine Conch. p. 249, f. 104. 
Papuana, young, Brown, Illust. Conch. G. B. p. 77, pl. 27, f. 5, 6. 


”° 


It is not improbable that formerly this elegant little shell 
has been passed over in Great Britain as the young of 


188 MYTILIDA. 


Modiolus, from which, however, its brilliant colouring will 
almost always distinguish it. The JZ. Australis of Gray 
is much more closely allied to it, and indeed is barely 
distinguishable in certain of its forms. 

Typically this is a thin and elongated species, and is 
rather more produced when adult than are individuals of 
Modiolus of similar dimensions; to that species indeed its 
general outline and characters wear so close a similitude, as 
to render unnecessary any detailed account of its propor- 
tions. It is rather more cylindrical, being somewhat more 
swollen at the diagonal elevation, is usually less broad at 
the hinder termination, and has the upper posterior outline 
occasionally, but obscurely, subretuse; the anterior side, 
although very short, is nevertheless rather more prominent 
likewise. The epidermidal coating is, in our British spe- 
cimens, of a fulvous cast on the adult, and bright yellow in 
the immature examples, and being transparent, exhibits the 
exquisite crimson painting which ornaments the posterior 
surface of the valves. This painting consists of narrow and 
generally numerous linear rays, either simple or more 
usually composed of linear angulations; occasionally the 
entire posterior triangle is wholly or partially clouded with 
these minute and radiatingly disposed zigzag lines. We 
have not perceived any distinct beard on any of the indi- 
viduals we have examined. The beaks are sometimes 
stained with crimson. The internal nacre, which has often 
a pale bluish cast, generally, if not always, displays the 
external radiation. Our largest typical specimen only 
measures an inch and a half in length, and three-quarters 
of an inch in breadth. Dr. Philippi, whose Sicilian ex- 
amples are identical with those we have ourselves taken, 
but have their epidermis of a brownish horn-colour, mentions 
a variety with violet rays, and another with only obsolete 


MODIOLA. 189 


radiations on a rufous ground, The former variety, which 
is remarkably scarce in Great Britain, we have figured 
from a very large specimen belonging to Mr. Jeffreys ; it 
measures quite two inches in length, and displays very 
characteristically the elongated dorsal margin, a feature 
which enables us to readily distinguish the adult of this 
species from Modiolus. The violet rays in this example are 
almost concealed by the epidermis, but are distinctly visible 
when the shell is held up to the light. 

The animal is oblong, its mantle is yellowish-white, plain- 
edged, freely open in front, and round as far as the distinctly- 
formed but short anal tube; the branchial region is slightly 
pouting, and quite plain. The foot is cylindrical, bluish- 
white, and grooved along its length. The byssus is yellow- 
ish. The branchiz are pale brown. 

This species is an inhabitant of our western shores, and 
is sparingly distributed, yet by no means uncommon. 
Channel Islands (S. H.); West bay of Portland in fifteen 
fathoms, gravel, and in seven fathoms at Dartmouth 
(M‘Andrew and E. F.); Exmouth (Clark); Torquay 
(S.H.); Milford Haven in ten fathoms, and Anglesey in 
from seven to forty fathoms (M‘Andrew and E. F.). In 
forty-five fathoms off Foula, Zetland (M‘Andrew.) ‘“ Very 
rare on the Irish coast, but obtained on each side of the 
Island.” Belfast Bay (Mr. Hyndman and W.T.); Mala- 
hide and Portmarnock (Dr. Lloyd and Mr. Warren) ; 
Birterbuy Bay, “ Dr. Farren” (W. Thompson); Bantry 
Bay in fifteen fathoms (M‘Andrew). 

It ranges to the Mediterranean. 


190 MYTILID&. 


M. sarpata, Linneus. 


Mussel-shaped, subarcuated, and somewhat lobed below ; epi- 
dermidal byssus serrated at the edge; surface with concentric 
wrinkles ; dorsal angle much raised ; beaks quite terminal. 


Plate XLIV. fig. 4. 


Mytilus barbatus, Linn. Syst. Nat. ed. 12, p. 1156 (from type). — Pout, Test. 
Sicil. vol. ii. p. 210, pl. 32, f. 6, 7. 

Modiola Gibbsit, Lyacu, Zoolog. Miscellany, vol. ii. p. 34, pl. 72, f. 2. — Turr. 
Dithyra Brit. p. 200.— FLEemine, Brit. Anim. p, 413. — 
Brit. Marine Conch. p. 107.— Brown, Ill. Conch. G. B. 
96 (ky Joly Plot Ze 

barbata, LAMARcK, Anim. s. Vert. (ed. Desh.) vol. vii. p. 22.— 
Puuiirpri, Moll. Sicil. vol. i. p. 70, and vol. ii. p. 50.— 
HAnt. Recent Shells, vol. i. p. 233. 


” 


This rough-looking shell is, from its great attenuation in 
front, of a subtriangular figure, and often subarcuated ; the 
beaks being absolutely terminal, there is no appearance of 
any anterior side beyond them. The valves, which are 
opaque and moderately strong, are decidedly compressed, 
except at the umbonal region; the diagonal elevation is 
broad, and not at all carimated ; the portion which precedes 
it is remarkably small and narrow. Beneath the glossy ful- 
vous epidermis which veils the external surface the shell is 
white, or stained upon the posterior triangle with scarlet or 
rose-colour; almost the entire exterior is, however, concealed 
by a most closely-disposed shaggy beard, whose terminal 
filaments are finely but distinctly serrated on that edge 
which looks towards the ventral margin. The appressed 
and broadly triangular bases of these processes (frequently 
in the case of dead specimens the only vestige of the byssal 
garment) are arranged in concentric lines, inducing regular 
crowded and often coarse wrinkles upon the epidermis. 
The hinder dorsal edge, which is greatly elevated, forms a 


MODIOLA. 191 


central well-marked but rounded off obtuse angle with the 
upper posterior outline, which is but little arcuated; the 
hinder extremity is very broad, and rather more prominent 
above than below. The ventral margin is often much in- 
curved, and there is a decided projection of its posterior 
end beyond the general outline. The internal surface is of 
a subnacreous white, and often stained with purplish rose- 
colour at the upper portion. 

The breadth of a fair sized specimen was one inch, and 
its length an inch and a half. 

The animal of Modiola barbata was observed by Poli, 
and has recently been examined by Mr. Clark, during the 
autumn of 1848; he describes it as elongated, thick, 
mantle freely open and for some little depth, with double- 
edged reddish-brown margins. The body is large, sub- 
rotund, and brown; from it springs a byssal foot, with a 
large cavity in the hinder part for a fine bushy dark 
byssus; the remainder of the foot is finger-shaped, not 
pointed, white, and longitudinally grooved. The branchis 
are brown and narrow ; the upper leaflet of each pair is not 
half the depth of the lower. There are no tubes nor orifices 
in the mantle, and the branchial laminze are continued 
close to the posterior extremity. The palps are reddish- 
brown, long, flat, strongly striated transversely on the 
inside, and smooth on their outer surfaces. 

This is one of our rarer British shells, and essentially of 
a southern character. At Gorey, in Jersey, we have seen 
the beach strewed with them to the depth of some inches, 
at a spot where the rejectamenta of the oyster-fisheries were 
wont to be deposited (S.H.); but on the English coast 
individual specimens are much prized. It is taken, but 
rarely, at Torbay (Mrs. Griffith) ; Exmouth (Mr. Clark) ; 
off Portland in fifteen fathoms, Weymouth in nine 


192 MYTILIDA. 


fathoms (M‘Andrew and E. F.); and at Milford Haven. 
Mr. Bean states that it occurs, though rarely, at Scar- 
borough, a locality not consistent with its known distri- 
bution. In from three to ten fathoms among weeds, at 
Clew Bay in the West of Ireland (R. Ball, W. Thompson, 
and E. F.); Youghal, very rare (R. Ball). 

It is a member of the Lusitanian fauna, and ranges into 


the Mediterranean, where it is common. 


M. Batty, Brown. 


Modiola Baillii, Brown, Ilust. Conch. G. Brit. and Irel. p. 132, pl. 42, f. 34, 35. 
5 vestita, THOMPSON, Ann. Nat. Hist. vol. xv. p. 318. 


Most unfortunately the single specimen from which this 
species was described and figured, cannot at present be 
found by its possessor, Mr. R. Ball, who courteously reply- 
ing to our inquiries for further particulars to verify its in- 
digenousness, states, that it came into his possession, appa- 
rently quite fresh-looking, along with other undoubtedly 
Irish shells sad to have been found in Ardmore Bay. We 
cannot venture to include this shell among our native 
species on the evidence of report alone; we transcribe, 
however, the description published by Captain Brown from 
the lost specimen. 

‘‘ Shell transversely oblong-ovate ; umbones placed very 
near to one side; a slight groove or furrow emanates from 
the umbones, and terminates in an oblique line on the mar- 
gin of the anterior side, on which the colour is golden- 
yellow ; covered with a very glossy olivaceous epidermis, 
which in certain lights exhibits a metallic lustre; inside 
highly pearlaceous, with transverse wrinkles towards the 
extremity; the surface exhibiting gold and coppery 
metallic reflections, and studded with a number of small 
circular pits like those left by the small-pox.” 


MODIOLA. 193 


Mr. Alder, who made an accurate drawing of the type, 
whilst temporarily in his possession, has transmitted us a 
foreign shell, which, on comparison, he at that time re- 
garded as identical with it. This is the M. agglutinans 
of Cantraine, (Bulletin Acad. Sciences Naturelles de Bru- 
xelles, 1835, 11. p. 398) subsequently (1844) and provision- 
ally termed vestita, in the second volume of his admirable 
work upon Sicilian shells (Hn. Moll. Sicil. vol. ii. p. 51, 
pl. 15, f. 12), by Dr. Philippi, who had lost the name under 
which he had received it from Malta. As that species 
was also unhesitatingly pointed out by Mr. Thompson, well 
acquainted with Mr. Ball’s example, in Mr. Cuming’s 
ample collection of exotic Modiola, we have appended a 
careful description of it, since the excellent Latin one of 
the German naturalist may not be in the hands of many 
students of British Conchology, with the aim of enabling 
any fortunate discoverer of further examples of Ballii, 
to determine with still greater exactitude its relation with 
the curiously encased Mediterranean shell, which imbeds 
itself in a felt-like ball or coccoon, entangling or immeshing 
stones fragments of other shells and various marine bodies 
in its external coating. 

Oblong, slightly cylindraceous, rather oblique, thin, ven- 
tricose, covered with a shining yellowish chestnut epider- 
mis, under which the surface has an uniform whitish hue ; 
concentrically marked with rather distant wrinkles of in- 
crease, which are usually obsolete in the younger examples, 
but entirely devoid of folds, undulations, or any other kind 
of sculpture. Surface diagonally divided into two areas, 
(of which the posterior is manifestly the larger, and the 
more convex) by the abrupt frontal elevation of the broad 
umbonal fold, the upper portion of which presents likewise, 
in the adult, a brighter and more yellow cast of colouring. 
Hinder dorsal edge nearly straight, and a little elevated, 
rather long in the young, about equal to the arcuated pos- 
terior margin in the adult. Ventral edge slightly lobed 
behind, obliquely ascending in front. Anterior side, though 
very short, distinctly projecting, unsymmetrically rounded 

VOL. II. cig 


194 MYTILID&. 


at the extremity. Termination of the posterior side, which 
is but little dilated, rounded, but not broadly so. Um- 
bones prominent, not wide; beaks acute, leaning forward, 
slightly subspiral, not preceded by any lunule-like dulness. 
Interior subnacreous white, not stained with coloured 
markings; hinge-margin a little reflected in front, not cre- 
nated or denticulated, in aged shells subemarginated above 
immediately under the beaks. Length of a rather large 
individual an inch and three-eighths; breadth scarcely 
three-quarters of an inch. 

We have received the same shell, with the locality 
“‘ Georgia, United States,” attached, from one of our Ameri- 
can correspondents, as the M. castanea of Say (Journ. 
Acad. Nat. Sciences of Philadelphia, vol. ii. pt. 11. August 
1822, p. 266,) with whose language it is not at variance. 


CRENELLA. Brown. 


Shell equivalve, very inequilateral, tumid or compressed ; 
surface covered with an epidermis, and either entirely or 
partially ornamented by striae, radiating usually in two 
diverging fasciculi from the beak. Hinge margin toothless, 
generally crenulated; ligament linear, internal. Two 
unequal muscular scars, pallial impression obscure. 

Animal oblong, its mantle closed anteriorly, open in 
front and in the branchial regions where the margins, 
though not united to form a siphon, constitute pouting 
and more or less puckered branchial lips; formed into a 
true and produced tube anally. Adductor muscles un- 
equal. Foot narrow, ligulate, furnished with a byssal 
groove. 

This group of Modiole, as they are usually considered, 
has a fair claim to generic rank, equivalent to that of 


CRENELLA. 195 


Mytilus and Modiola. For it we adopt the designation 
given to Crenella decussata, by Brown, who, however, did 
not perceive that he was constituting a genus, which really 
belonged to the Mytilide, and naturally included several of 
the shells ranked by himself as Modiole. The uncharac- 
terized genera Modiolarca, of Gray, and Modiolaria, of 
Beck, seem to be synonymous, certainly the latter, with 
Crenella in the extended sense in which we propose to 
adopt it. The members of the genus are very elegant 
little shells, and great favourites with collectors. The 
habit of boring into the test of Ascidie, indicates an 
affinity, evident also, on comparison of shell and animal, 
with Lithodomus. 


C. piscors, Linneeus. 


Moderately ventricose, not marbled, smooth in the middle, 
rayed with impressed lines (occasionally almost obsolete poste- 
riorly) at the sides; hinder area elevated, somewhat lobated 
below. 


Plate XLV. fig. 5, 6, and Plate XLVIII. fig. 5. 


Mytilus discors, Linn. Syst. Nat. ed. 12, p. 1159 (from type). — Lovin, Index 
Moll. Skandinay. p. 33. 
discrepans, Mont. Test. Brit. p. 169.—Turv. Conch. Diction. p. 112.— 
Dititw. Recent Shells, vol. i. p. 319. 
discors, var. 8. Maton and Racxerr, Linn. Trans, vol. viii. p. 111, 
16 By te BE 
Modiola discrepans, LAMARcK, Anim. s. Vert. (ed. Desh.) vol. vii. p. 23. — 
Turt. Dithyra Brit. p. 202.— Fores, Malacol. Mo- 
nensis, p. 44.— Brit. Marine Conch. p. 108 (chiefly). — 
Aver, Cat. Moll. Northumb. and Durh. p. 81.—Goutp, 
Invert. Massach. p. 129, f. 83 (probably).—HANL. Recent 
Shells, vol. i. p. 242. 
(Unnamed.) Brown, Il. Conch. G. B. pl. 39, f. 36. 
? Modiola minuta (fry), Coucu, Cornish Fauna, pt. 2, p. 33 (not described). 


rr) 


” 


A careful examination of the Linnzan cabinet enables us 
to state positively, that this is the species intended by the 


196 MYTILIDA. 


illustrious Swede, under the name discors. His descrip- 
tion was very accurate, and more extended than was usual 
in the “Systema”; the somewhat puzzling assertion, that 
the strie are almost transverse, arose from his regarding 
the attenuated end, and the wide posterior termination of 
the mussels as top and bottom. 

The valves which are subovate, manifestly dilating pos- 
teriorly, instead of being swollen as in marmorata, are but 
moderately convex, and are even shallow at the extre- 
mities. Considering their thinness and fragility, they are 
rather opaque, and are covered with a closely adherent epi- 
dermis of various shades of green and olive, more usually 
in northern examples of an olivaceous brown, generally 
with a greenish cast towards the edge, and in southern 
specimens of a somewhat tawny olivaceous green. The 
shape of the former of these two varieties, we may remark, 
is more abbreviated, and the dorsal line is rarely quite 
equal, as in the latter and more produced form, to the 
space behind it. Of the three subtriangular compartments 
into which the surface is divided, the posterior is slightly 
the more elevated, and is rather more than equal in extent 
to the two remaining ones. Typically, it is crowded with 
most numerous radiating rib-like strie, which are simple, 
not crenated, closely set, but little raised, and, in the adult, 
almost invariably grown obsolete, except near the ventral 
margin. There are a few distinct radiating costelle upon 
the anterior portion, which are rather broad, not much ele- 
vated, and sufficiently apart : the central area is devoid of 
any sculpture, and appears rather abruptly terminated 
behind by the superior elevation of the posterior portion. 
The general inclination of the ventral margin is not far 
from straight, but its outline is rather flexuous in detail, 
arching out more or less in the middle, and again, more or 


CRENELLA. 197 


less abruptly, at the commencement of the posterior compart- 
ment, so as to render the latter sublobated in appearance. 
The hinder dorsal edge sloping upwards in a nearly straight 
and moderately ascending line unites itself with scarcely 
any angulatien to the posterior outline: this latter forms 
an uninterrupted sweep to the commencement of the sublo- 
bated portion ; its chief swell being nearly in the middle, 
whence it so runs downwards as to give a slightly trunca- 
ted look to the lower part of the hinder extremity. Both 
extremities of the shell are rounded, though neither of 
them symmetrically so. The umbones are not prominent ; 
the beaks are nearly terminal, acute, and much inflected. 
The interior is iridescent white, with its margin only cre- 
nated at the extremities. 

A large individual now before us, measures seven tenths 
of an inch in length, and five lines in breadth. 

“The animal,” says Mr. Alder, in his Catalogue of the 
Mollusca of Northumberland and Durham, ‘‘is white, and, 
assisted by its long strap-shaped foot, can move about 
pretty quickly ; but it generally prefers a stationary life, 
and forms for itself a kind of nest or case, by stitching to- 
gether the small sea-weeds and corallines with its byssal 
threads ; here it remains attached by its byssus, awaiting 
the food that may come within its reach. When viewed 
in a living state there appear to be two syphons at the 
longer end of the shell, but only the posterior of these has 
the walls complete ; the other has its anterior side open, 
formed by a fold in the cloak, as in the siphons of the 
zoophagous gasteropods. The animal has consequently 
only two pallial apertures.” 

Common all round our shores, and often very plentiful 
among the roots of Laminarie and among corallines. It 
ranges from low-water mark to thirty fathoms, at which 


198 MYTILID&. 


depth we have found it in the Irish Sea, off Anglesea, in 
the line of strong currents, enveloped in nests formed of 
fragments of Flustra foliacea and masses of sand aggluti- 
nated together and combined by byssal threads. Mr. 
Alder has observed a slender nearly smooth variety among 
the rocks at Staffa. It ranges throughout the European 
seas, and probably also to the shores of Boreal America. 


C. marmorata, Forbes. 


Tumid, oblique, usually marbled with coloured markings, 
smooth in the middle, rayed with impressed lines at both ex- 
tremities ; beaks quite terminal. 


Plate XLV, fig. 4. 


Mytilus discors (not of Linn. nor Fabr.), Da Costa, Brit. Conch. p. 221, pl. 17, 
f.1.— Puttrrenry, Hutchins, Hist. Dorset. p. 38. — Donov. 
Brit. Shells, vol. i. pl. 25, f. 1. — Monv. Test. Brit. p. 167.— 
Maron and Rack. Linn. Trans. vol. viii. p. 111. (not var.) 
pl. 3, f. 8.— Laskey, Mem. Wern. Soc. vol. i. p. 393. — 
Racket, Dorset Catalog. p. 40, pl. 2, f. 1.—Turz. Conch. 
Diction. p. 112.—Poxt, Test. Sicil. vol. ii. p, 211, pl. 32, f. 15. 


—Ditiw. Recent Shells, vol. i. p. 319. Index Testaceolog, 


pl. 12, f. 39.—Mawe, Conchology, pl. 13, f. 5. 
Modiola ,, (not of Lamarck), Turton, Dithyra Brit. p. 201, pl. 15, f. 4, 5.— 
Fiemine, Brit. Anim. p. 413.— Maceiuiv. Moll. Aberd. 
p- 239.—Brit. Marine Conch. p. 108. 
Mytilus discrepans, DESHAYES, Encyclop. Méthod. Vers. vol. ii. p. 567. 
Modiola marmorata, Forzers, Malacol. Monens. p. 44, — Brown, Ill. Conch. 
G. B. p. 78, pl. 27, f. 10. 
4»  diserepans, Purieri, Moll. Sicil. vol. i. p. 70, and vol. ii. p. 50, pl. 15, 
5 Wl. 
,,  tumida, Hanu. Recent Shells, vol. i. p. 241, pl. 12, f. 39. 
5  LPoliana, Puiuiprt, Zeitschr. Malacol. 1844, p. 101 (from type). 


Few shells have been the subject of more discussion 
than the Mytilus discors of Linnzus, which epithet, usually 
bestowed by foreign writers upon the large Australian 
species (dmpacta), has, till of late years, been almost uni- 


~ 7 


CRENELLA. 199 


versally claimed by our own authors for the shell we are 
about to describe. The all but simultaneous observation 
of its distinctiveness by three conchologists has caused the 
imposition of three new names upon this long known 
mussel. The valves are thin, fragile, obliquely oval or 
rather subtrapeziform in figure, and greatly swollen ; the 
swell is chiefly manifest upon the umbonal ridge, which is, 
however, rounded and not carinated, and is not followed 
by any retusion of surface, or any abrupt compression. 
The exterior, which is covered with a thin shining trans- 
parent epidermis, varying from greenish oil-colour to a 
clear light brilliant green, is more or less painted with 
minute linear angulations of a liver-colour. upon a pale or 
whitish ground. It is divided into three compartments, of 
which the hinder is about equal to the other two united, 
its front limit usually defined in the adult by a slight re- 
tusion, that almost diagonally runs across the shell. The 
anterior space, which is the smallest of the three, is radiated 
with at least a dozen most closely set costellee or small 
ribs, whose surfaces are obtuse and but little convex, 
which are but little raised above their narrow interstices, 
and which, although not really crenulated, often appear so 
from the epidermidal wrinkles. The middle space is 
smooth, and has the shape of a curvilinear triangle. The 
hinder or terminal compartment, which commences a little 
before the umbonal fold, is radiated similarly to the 
front area, but has its more numerous costelle so much 
more crowded that it should be rather termed striato- 
suleated than ribbed. The upper and lower margins of 
the shell run nearly parallel to each other, and are 
straightish in their general outline ; the ventral edge, how- 
ever, swells out a little in the centre of the middle com- 


partment, and appears subretuse at its extremities; it 


200 MYTILIDA. 


rises too, far more obliquely and rapidly in front of the 
shell than at its termination. The umbones are swollen, 
and the beaks are terminal or nearly so, not unfrequently 
projecting beyond the curved anterior outline. The hinder 
end, which, from the greater projection below of the 
produced and arcuated posterior outline, occasionally ap- 
pears bluntly wedge-shaped, is also rounded both above 
and below, there being no decided angulation of the hori- 
zontal (or even ascending) dorsal margin, which, moreover, 
rarely exceeds the length of the space that extends from its 
cessation posteriorward. 

Three-quarters of an inch in length, and about five lines 
in breadth, are the dimensions of rather a large individual. 

The animal of this species was carefully examined by 
Mr. Clark in 1835, and re-examined by that excellent 
observer last year. His notes are of such interest, that 
we print them entire as communicated. ‘“ Animal elon- 
gated, thick, oval, pale yellow; mantle closed in the ante- 
rior ventral half, where it makes a considerable opening for 
the emission of the foot; it is then again closed and forms 
a red purplish and flaky-white membrane, which is pro- 
duced into a small cylindrical anal tube, grooved at the 
base, and with four or five very minute dark cirrhi at the 
terminus. This grooved anal siphon carries on each side 
of it the mantle formed into small pendulous flaps of the 
same colour as the tube, and the animal by bringing their 
margins into contact forms together with the groove under 
the anal tube a canal to convey water to the branchie ; 
excepting these small puckered flaps, the margin of the 
mantle where open is plain. The foot is white with a very 
deep byssal groove at the point of its elbow, from whence 
a strong byssus issues and fixes the animal to shells, 
stones, the Ascidia mentula, &c. The anterior part of the 


EE —————<—— a 


CRENELLA. 201 


foot is white, very narrow, and finger-shaped, moderately 
pointed; but when fully extended it takes the form of 
a very narrow flat tape, with a slight brown line running 
longitudinally from its base to the point: it is protruded by 
the animal close by the anterior side of the byssus. As an 
organ of locomotion it can be of little use until the animal 
liberates itself, which it has, we believe, the power of doing 
to change place: it may be of use as an organ of tact. 
Change of place can only be effected when it is fixed to 
stones, and not when buried in the coriaceous coat of the 
Ascidia. Its mode of operation to detach itself from 
stones, &c., is to discard the old byssus and spin another 
elsewhere, as we have seen. There are on each side of the 
body two pale orange-coloured branchie, smooth on all 
surfaces; also two subtriangular, long, pointed, pale brown 
pectinated, pendulous palps.” 

C. marmorata is common wherever Ascidie are found, 
all round our coasts, and in many places is very plentiful, 
enjoying a range in depth of from low-water mark to forty 
fathoms. It burrows in the tests of tunicated mollusks, 
especially Ascidia mentula. ‘In the skin of Cynthia 
tuberosa and Ascidia sordida, especially the latter” 
(Alder). ‘In the coats of tunicated mollusks generally, 
both simple and compound” (W. Thompson). It ranges 
throughout the European seas, and is an ancient species, 
dating its appearance within our own area from the epoch 
of the coralline crag. 


VOL. II. DD 


202 MYTILID&. 


C. nicra, Gray. 


Elongated, rather compressed, not distinctly lobated, most 
closely radiated (except in the middle) with raised and crenu- 
lated striz ; epidermis brown in the adult, greenish in the young. 


Plate XLIV. fig. 5, and (Animal) Plate Q, fig. 7. 


Mytilus discors, var. CHEMN. Conch. Cab. vol. viii. p. 195, pl. 86, f. 767. 
= >  ScHROTER, Einleit. Conch. vol. iii. pl. 9, f. 15. 
= » var. Suecicus, O. Fasr. K. Dankse Videnskab. Selskab. (Nye 
Samm.) 1788, p. 460 (in part). 
5  discrepans, Mont. Test. Brit. Suppl. p. 65, pl. 26, f. 4. —Lxacu, Zoolog, 
Miscellany, vol. ii. p. 36.—Index Testaceolog. pl. 12, f. 38. 
Modiola nigra, Gray, Appendix to Parry’s Voyage to North Pole. — Brit. Ma- 
rine Conch. p. 249, f. 5. —ALpxEr, Cat. Moll. Northumb. and 
Durh. p. 81.— Hanu. Recent Shells, vol. i. p. 242, pl. 12, 
f. 38. 
»  discrepans, FLEMING, Brit. Anim. p. 413. — Maceirtty. Moll. Aberd. 
p- 288. — Brown, Ill. Conch. G. B. p. 78, pl. 27, f. 8.— 
Sowersy, Genera Shells , Modiola, f. 3.—REEvE, Conch. 
Systemat. pl. 100, f. 3.— Puitieri, Zeitschr. Malacol. 
1844, p. 102. 
» compressa, MENKE, Cat. Conch. Malsburg (from Chemnitz’s fig.). 
oF depressa, HANL. Recent Shells, vol. i. p. 242, note. 
Crenella nigra, Kine, Ann. Nat. Hist. vol. xviii. p. 239. 


Although this rare shell was delineated in Montagu’s 
Supplement to the ‘'Testacea Britannica,” as a large ex- 
ample of his discrepans, the specific differences are of an 
easily appreciable character: the most readily perceptible 
are the nature of its strie, and the absence of any 
marked lobation. Its shape is more or less oblong, and 
slightly arcuated ; dilating chiefly just behind the middle, 
and again attenuating posteriorly, it becomes decidedly nar- 
row at the front extremity, which latter projects rather 
more than in our discors, as the acute and tolerably promi- 
nent beaks are not quite terminal. None of the British 


examples we have seen are otherwise than fragile and 


Pitme mney 


ORENELLA. 203 


rather thin ; those from Newfoundland, however, are con- 
siderably more solid. The epidermis, which entirely clothes 
the surface, and which shines with a resinous lustre, varies 
in colour according to the age of the specimen ; in the young 
it is tawny, with an olivaceous tinge, changing into green 
towards the front of the shell; old specimens are of an 
almost uniform pitchy brown; intermediate stages of an 
olive green in front, and chestnut or tar-coloured posteriorly. 
The valves are shallow, especially in front, and are much 
more compressed below than those of the true discors. The 
general inclination of the ventral edge is retuse in the adult, 
and nearly straight in the young, there being no decided 
bulging out of outline in the centre, nor any marked pos- 
terior lobation. The hinder dorsal edge is nearly recti- 
linear, only very moderately elevated, and so perfectly 
free from angulation at its junction with the hinder margin, 
that its point of union is almost imperceptible; the latter 
slopes gently downward in a long arcuated sweep from the 
highest point, (which is usually either midway from the 
front extremity, or else from the beaks,) so that the chief 
swell is below the middle of the posterior side, which, as 
well as the anterior, is well rounded. There is no abrupt 
depression of surface preceding the posterior compartment, 
which in truth is little raised above the rest of the area, 
and almost comprises two-thirds of the entire superficies: 
this portion is occupied by most numerous elevated radi- 
ating strie. These, although crowded, are distinctly se- 
parated from each other, and particularly towards the 
upper or dorsal edge, are distinctly crossed, as well as their 
interstices, by fine raised concentric striule, which subgra- 
nularly crenate (and occasionally even imbricate in a slight 
degree) the radiating ones; the latter do not suddenly 
cease in front, but gradually diminish in elevation and 


204 MYTILIDA. 


thickness. Similar rib-like striee adorn the anterior com- 
mencement of the shell; the intermediate area is apparently 
smooth, but when highly magnified, displays an elegant 
chasing of minute and often interrupted concentric wave- 
like corrugations. The interior is subnacreous white, with 
a somewhat livid cast ; the margin is not crenulated in the 
middle, but in aged and large examples becomes not unfre- 
quently subgranular near the beaks. An individual, which 
we regard as rather large for a British specimen, measures 
three-quarters of an inch in breadth, and an inch and three- 
tenths in length. Our Newfoundland examples are at 
least two inches in length, and full half that breadth; and 
both Dr. Fleming and Mr. Barlee state that British indi- 
viduals of two inches in length are occasionally to be met 
with. 

The animal of this species has been observed by Mr. 
Alder, who kindly communicated the drawing from which 
we have taken our figure. It is of a transparent white 
hue, with the margin of the cloak and syphon tinged with 
pink, and speckled with brown and opaque white. 

This rare and fine shell is of boreal origin, and in Britain 
occurs only in northern habitats. It has long been known 
in the Frith of Forth, where we have dredged it on the 
oyster-beds in seven fathoms; and in a MS. note of 
Captain Laskey’s it is remarked that this species was 
originally much more plentiful there than latterly, the 
numbers having been diminished by the avidity with which 
it was sought after by fishermen, on account of the ready 
sale they found for specimens. In England it is only known 
from the North Eastern coast, where it has been taken at 
Cullercoats by Mr. Alder, who also enumerates among its 
localities “ Whitburn (Rev. G. C. Abbes). Mr. Howse 


dredged it alive in seventeen fathoms. Mr. King has also 


CRENELLA. 205 


got it from the fishing-boats.” Rare at Scarborough 
(Bean). Lieutenant Thomas has taken it in seven fathoms, 
off the Dudgeon, in the Frith of Forth, and in Orkney. 
It has occurred at Oban in eighteen fathoms, on the west 
coast of Zetland in seventy fathoms, and on the same coast 
as deep as ninety at a distance of thirty miles from shore, 
(M‘Andrew and E. F.) Mr. Jeffreys has taken it in 
several localities in the Hebrides. Mr. Alder remarks that 
Oban specimens are broader than usual posteriorly, and 
have a greenish epidermis. 

It is a well-known inhabitant of the banks of Newfound- 


land, and, in Europe, of the Norwegian seas. 


C. costuzata, Risso. 


Oblong, marbled with livid zigzag lines, with radiating 
grooves at each end ; anterior extremity very narrow, distinctly 
projecting beyond the umbones. 


Plate XLV. fig. 1. 


Modiola costulata, Risso, Hist. Nat. l’Europe Mérid. vol. iv. p. 324, f. 165 (fide 
Philippi—badly fig. and descr.).—Jerrreys, Annals Nat. 
Hist. vol. xix. p. 313. — Puriprt, En, Moll. Siciliz, vol. 
ii. (mot vol. i.) p. 50, pl. 15, f. 10 (not of D’Orbigny 
Moll. Canarr. nor Hanl. Recent Shells, vol. i. p. 240). 


This very beautiful shell, whose existence in our seas 
was first indicated by Mr. Jeffreys in the nineteenth vo- 
lume of the “ Annals of Natural History,” but of which 
no description has hitherto been published in any English 
work, might, at first sight, be passed over as either 
marmorata or discors, to both which species it bears 
considerable resemblance, uniting the general shape and 
characters of the latter to the marbled painting of the for- 
mer. Its form is more elongated than that of either, 


206 MYTILIDZ. 


and exhibits a different proportion in its component parts. 
We must preface our description of this shell by observing, 
that we have seen too few specimens of it to determine 
whether the characters we have noted and delineated 
should be regarded as essential, or as liable to alter- 
ation. Of its distinctness as a species, we entertain 
no doubt. The valves are small, oblong, or elongated ob- 
long, and much narrowed in front; they are moderately 
thin, ventricose, and covered with a lustrous epidermis of a 
clear semi-transparent bluish green, beneath which the shell 
is variegated with zigzag markings of a reddish liver colour 
on a paler ground; this marbling is not partial or confined 
to the umbones, although more profusely displayed there, 
or from the greater tenuity of the epidermis at that part, 
more distinctly apparent upon them. The external surface 
is radiatingly divided into three areas, of which the hinder, 
although occupying twice the actual superficies of the other 
two united, does not extend at the ventral margin to quite 
the middle of it, although advancing further than in the 
two species previously referred to. This area, which in our 
most characteristic examples is abruptly elevated above the 
general level, is closely radiated with, at least, twenty 
sulci, whose terminal interstices in the larger individuals 
are elevated into distinct costellee, with faint and close con- 
centric strie in their intervening furrows. The few de- 
pressed ribs which occupy the anterior area are broad and 
rather far apart, their imterstices about equalling them ; 
the line of demarcation between them and the smooth and 
larger central area is not defined. At the junction of the 
front and middle areas, the ventral margin, whose general 
outline is straightish, is a little retuse; it swells out again a 
little in the centre, becomes again retuse, and finally, by its 


sudden projection along the base of the hinder area, gives 


CRENELLA. 207 


that portion of the shell a lobated appearance. The anterior 
half of the shell is mnch narrower than the posterior,—the 
shell being regularly attenuated to its front extremity, 
which is extremely narrow, well and not obliquely rounded, 
and distinctly projecting beyond the umbones. ‘The 
straightish and ascending hinder dorsal edge, having united 
with the posterior one without angularity, runs in a gentle 
arcuated sweep to the posterior extremity, and thence sud- 
denly descending, forms a broad and rounded termination 
to the shell. The umbones are but little swollen ; the in- 
terior is brilliantly nacreous, with the margin distinctly 
crenated at the bases of the ribs. 

The very beautiful example which we have figured from 
Mr. Jeffreys’s unrivalled collection, measures half an inch in 
length, and rather more than a quarter of an inch in 
breadth. These dimensions exceed those assigned to the 
Mediterranean examples by Dr. Philippi, from whom we 
have received small specimens, that perfectly agree with our 
own in contour, sculpture, and painting. The ribs are not 
very distinctly developed in the younger shells (nor upon 
the umbonal region of the adult); neither at that stage 
does the epidermis display the verdant hue which so orna- 
ments the surface of the mature shell. 

It has been taken at Exmouth by Mr. Clark, in Corn- 
wall by Mr. Alder and Miss Lavars, and at low-water 
mark in Oxwich Bay, near Swansea, by Mr. Jeffreys. 


208 MYTILIDA. 


C. ruompea, Berkeley. 


Very small, somewhat rhomboidal, whitish; entire surface 
sculptured with radiating lines. 


Plate XLV. fig. 3. 


Modiola Prideauxiana, Luacn, Zoolog. Miscellany, vol. ii. p. 35-— Brown, Ill. 
Conch., G. B. p. 78, pl. 27, f. 9. 
»  rhombea, BERKELEY, Zoolog. Journal, vol. iii. p. 229, suppl. pl. 18, f. 1 
—Brit. Marine Conch. p. 107.— Brown, IIl. Conch. G. B. 
p. 78, pl. 39, f. 17. 


Although this extremely rare shell had previously been 
observed by Dr. Leach, yet as his brief description, unac- 
companied by a figure, is so entirely inadequate for its re- 
cognition, that, without a knowledge of the typical example, 
it would have been impossible to ascertain what was intended 
by it, we have preferred the name subsequently assigned to it 
by Mr. Berkeley. It is a remarkable-looking species, and 
incurs not the slightest risk of being mistaken for any other 
British shell, but bears, when worn, a close resemblance to 
the young of (@. sulcata. The shape is rather oblique, 
somewhat rhomboidal, and occasionally a little arcuated ; 
the chief dilation is a little beyond the middle, the hinder 
termination being distinctly attenuated. The valves, which 
are white, covered when recent with a pale yellow epi- 
dermis, are much swollen, or gibbous, above upon the um- 
bonal fold, but are compressed near the dorsal angle, and 
rather quickly diminish in convexity towards the ventral 
margin. Their texture is rather strong for their size, and 
neither transparent nor vitreous; the exterior is not polished, 
though a little glossy, and is most exquisitely sculptured by 
radiating lines, which are delicate and most closely set 
in front, but elevated, more distant, a little divergent, and 
often bifurcated posteriorly. In the perfect state these are 


CRENELLA. 209 


fringed, as it were, by rather remote and very delicate 
concentric lamin, that are chiefly apparent on, if not in- 
deed confined to, the hinder portion of the shell, and when 
worn off, indicate their former presence by a kind of inter- 
rupted or obsoletely articulated appearance which they be- 
stow upon the radiating striz. The ventral margin is retuse 
in the middle, and convex at the extremities ; it ascends more 
rapidly, but still arcuatedly, in front. The hinder dorsal 
edge, which, although constantly elevated, varies much in 
height, rendering the shell more elongated when the dorsal 
angle is less developed, more abbreviated when the rise is 
more manifest, forms a rounded off but distinct angle with 
the posterior margin; the latter, after arching out, be- 
comes incurved a little below the middle of the hinder side, 
thus giving a somewhat lobated appearance to the narrow 
and well-rounded tip of the posterior side. The beaks are 
prominent, and being terminal, project beyond the anterior 
end, which is not at all angulated, but is arcuatedly cut 
off below, so that the lower portion is the more receding. 
The largest recorded example is stated by Capt. Brown to 
have measured a quarter of an inch in length, and an 
eighth of an inch in breadth; such dimensions are, how- 
ever very uncommon, the average length not exceeding a 
fifth of an inch. Some of the best specimens as yet found 
are the two preserved in the National Museum, and pre- 
sented respectively by Mr. Prideaux, who obtained his 
shell on the Devonshire coast, and the Rey. Miles Berkeley, 
who dredged a single individual at Weymouth adhering 
by its byssus to a large mass of slate. Odd valves have 
occurred to us in shell sand from Herm (S. H.); Mr. 
M‘Andrew dredged it in 20 fathoms off Penzance, and 
Mr. Barlee off Brora Island. 


VOL. II. E E 


210 MYTILID®. 


C. pecussata, Montagu. 


Minute, obliquely suborbicular ; entire surface radiated with 
elevated strize. 


Plate XLV. fig. 2. 


Mytilus decussatus, Mont. (not Lamarck), Test. Brit. Suppl. p. 69. — Laskey, 
Mem. Wern. Soc. vol. i. pl. 8, f. 17. —Turt. Conch. Dic- 
tion. p. 114.—FLemine, Brit. Anim. p. 411. 

Crenella elliptica, BRowNn, Conch. Text-book (1833), p. 143, pl. 18, f. 13; Tl. 
Conch. G. B. p. 75, pl. 23, f. 12, 13, 14. 

2 Modiola glandula, TorreEn, Silliman’s Journ, yol. xxvi. p. 367, f. 3. — Gouxp, 
Invert. Massach. p. 131, f. 87.— Hant. Recent Shells, 
vol. i. p. 243. 

Crenella decussata, MAceiuutv. Moll. Aberd. p. 229.—Brit. Marine Conch. f. 5. 
—AtpeEr, Cat. Moll. Northumb. and Durh. p. 82. 

Modiola faba (not Mytilus faba of O. Fabric.), Brit. Marine Conch. p. 248. 

cicercula, MouuER. Index Moll. Groenlandie, p. 19. — HAnu. Recent 

Shells, vol. i. p. 243. 


” 


This pretty little species is very ventricose at the um- 
bones, whence its convexity regularly and gradually di- 
minishes in all directions. Its valves are thin and fragile, 
yet not particularly so for their minute size, and are covered 
with a rather dull ashy olivaceous or pale olive-coloured 
epidermis, beneath which the surface appears white. The 
very many raised and somewhat granulated striz, which 
radiatingly adorn the entire exterior, are all nearly equally 
strong, more or less divergent, and very closely disposed, 
since the interstices, as they widen, become filled up with in- 
termediate costellar striz ; the granules are much crowded, 
and very minute. The shape is so obliquely oboval, the 
beaks are so acute, and project so much beyond the front 
extremity (which, moreover, is obliquely cut off, as it were, 
below) that the natural mode of viewing the contour appears 
to be with the beaks upright and the central strie perpen- 
dicular ; in which case the former appear exactly in the 


CRENELLA. 211 


middle, and the two short dorsal edges, after forming a 
nearly similar angle, run with equal arcuation to the well- 
rounded base, so that the shell appears almost sym- 
metrically equilateral, and very like a minute and earless 
Lima. Holding it, however, in the same position as the 
Modiole, we should describe the hinder dorsal edge, as 
short, straightish, greatly ascending, and merging without 
marked angularity, into the posterior margin, which latter 
arching out with a bold sweep, and almost symmetrically 
rounding the hinder termination, passes without inter- 
ruption into the anterior or front ventral margin. Although 
single valves are found of larger dimensions, we have seen no 
pairs which have been taken in Great Britain, that measure 
more than a sixth of an inch in length and an eighth of an 
inch in breadth. Nevertheless, if, as we surmise, for we can 
perceive no variation of specific importance, the glandula of 
Totten prove identical, it attains to at least half an inch 
at Maine and elsewhere in the United States of North 
America. The shape of full-sized individuals of this Trans- 
atlantic variety is more rhomboidal and much broader, 
with a distinct curved anterior edge, which forms more 
than a right angle with the hinder dorsal margin. 

This is a northern species, first discovered by Laskey, 
and, until of late years, specimens were rare in cabinets ; 
the active exertions of Mr. Jeffreys, Mr. M‘Andrew, and 
Mr. Barlee, in little explored localities, have made it more 
common. On the English coast it has been found very 
rarely at Scarborough by Mr. Bean; off the shores of 
Northumberland, where it has been found at Cullercoats 
and Fern Island by Mr. Alder, by Mr. King in the cavity 
of a small stone from deep water, and by Mr. Howse, 
alive in seventeen fathoms. On the coast of Scotland it 
occurs in numerous localities from Oban round to the 


212 MYTILIDZ. 


Moray Firth and Aberdeenshire. The following instances 
will illustrate its range in depth,—Icolmkill, five fathoms ; 
coast of Zetland, abundant in Balta Sound in from five to 
ten fathoms, and ranging in other places as deep as fifty 
fathoms to fifty-five fathoms; nine miles off Cape Wrath, 
sandy ground, and in fifteen fathoms, Moray Firth (M‘An- 
drew). In from seven to fifteen fathoms, Orkneys 
(Thomas) ; moored by its byssus under stones at low water, 
Loch Carran (E. F.). “A few odd valves were dredged 
from about ten fathoms on a shelly bottom in Strangford 
Lough, by Mr. Hyndman and myself in August, 1832.” 
(W. Thompson.) 

It is a boreal shell, ranging along the coasts of Norway, 
Greenland, and Boreal America. 


SPURIOUS. 


Liruopomus aristatus, Dillwyn. 


Le Ropan, ADANSON, Senégal, p. 267, pl. 19, f. 2. 
Mytilus lithophagus striatus (1804), J. Sowrrsy, Linn. Trans. vol. viii. p. 274, 
pl. 6, f. 2. 
Mytilus aristatus (1817), Dituwyn, Recent Shells, vol. i. p. 303. — Index Tes- 
taceolog. pl. 12, Mytilus, f. 8. 
Modiola caudigera (1819), LAMARcK, Anim. s. Vert. vol. vi. pt. 1, p. 116.—Do. 
(ed. Desh.) vol. vii. p. 27.—HanL. Recent Shells, vol. i. p. 
238, pl. 12, Mytilus, f. 8—Purmipri, Abbild. Neuer Conch. 
vol. ii. p. 149, Modiola, pl. 1, f. 5. 
Lithodomus caudigerus, SowERBY, Genera Shells, Lithod. f. 4.—ReEEveE, Conch. 
Systemat. pl. 99, f. 4. 
Lithodomus lithophagus (not of authors), FLEmine, Brit. Anim. p. 414,— British 
Marine Conch. p. 111. 
Encyclopéd. Méthodique, Vers, pl. 221, f. 8. 


Introduced into British Conchology from having been disco- 
vered imbedded in stone used for repairing the roads near London, 
and surmised to have come from Plymouth. It is a native of 
Senegal and the West Indes. 


CRENELLA. 2S 


L. ruscus, Gmelin. 


ListER, Hist. Conch. pl. 359, f. 197.—Scurorer, Einleit. Conch. 
vol. iii. p. 459. 
Mytilus fuscus, GMELIN, Syst. Naturee, p. 3359 (only from Lister’s figure). — 
Ditiw. Recent Shells, vol. i. p. 806.—Brown, Mem. Werner. 
Soc. vol. ii, p. 513.— Tur. Conch. Diction. p. 113 (copied 
from last).—Index Testaceolog. pl. 12, f. 12. 
Modiola cinnamonea, var. LAMARCK, Anim. s. Vert. (ed. Desh.) yol. vii. p. 25. 
» fusca, DesHAyEs, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 28.— 
Han ey, Recent Shells, vol. i. p. 239, pl. 12, f. 12. 


An E. Indian shell ; introduced by Captain Brown, i the 
Wernerian Memoirs, as found at Sligo. 


214 


ARCADE. 


Tue shells of this family are easily recognized by the 
peculiar dentition of their hinges, which are furnished with 
small comb-like interlocking teeth, all similar, or differing 
only in size and often very numerous. The characters of 
sculpture, outline, size, and thickness vary in the several 
genera. The shells of all, however, are provided with an 
epidermis. The animals of all the forms have a deeply- 
grooved foot, capable of expanding into a disk like the foot 
of a gasteropod. The margins of the mantle are usually 
freely open, and not formed into tubes posteriorly, though 
in Leda, and probably in Solenella, they present the latter 
arrangement ; consequently, the form of the pallial im- 
pression in the shell varies in this tribe. There are con- 
stantly two adductor muscles, the impressions of which are 
strongly marked on the shells. The structure of the 
appendages of the mouth afford generic distinctions. 


NUCULA. Lamarck. 


Shell equivalve, inequilateral, shortened anteriorly, ovato- 
trigonal or obliquely ovate, closed, smooth, or concentrical- 
ly striated, or (in certain exotic and fossil species) marked 
by zigzag or radiating furrows; always invested with a 
smooth epidermis; margin denticulated or smooth; beaks 
approximated, incurved ; inside nacreous : hinge-line angu- 


NUCULA. 215 


lated, a ligamental fossette at the angle, and a range of 
comb-like, small, sharp teeth on each side ; ligament chiefly 
internal, Pallial impression entire. 

Animal subtrigonal, its mantle freely -open, without 
siphonal tubes and with plain edges. Foot deeply grooved 
and forming an ovate pedunculated disk with serrated 
edges. One in each pair of labial palps long, curled, linear 
and fimbriated at its margins; the other short and fili- 
form. 

The Nucule are beautiful little bivalves, remarkable for 
their clean and often glossy aspect and quaker-like hue of 
their coats. They live in sand or mud, and are never fixed, 
They inhabit all depths of water, from near tide-marks 
down to the deepest regions in which Mollusca have been 
found. The species are sparingly distributed throughout 
the seas of both hemispheres, and the genus, geologically, 
ranges back to the oldest fossiliferous strata. We adopt 
the group as restricted by Moller. 

Dr. Carpenter has examined the microscopic structure 
im our commonest British species of this genus, and finds 
the inner layer of the shell to present a truly nacreous 
structure ; in the outer a smaller amount of tubular struc- 
ture may be observed. 


N. nuctzus, Linneus. 


Never rayed ; epidermis not lustrous ; hinder extremity blunt, 
its dorsal area not sculptured ; inner margin crenated. 


Plate XLVIL. fig. 7, 8, and (Animal) plate P. fig. 4. 


Arca nucleus, LINN. Syst. Nat. ed. 12, p. 1143 (in part).—PEnnAnrT, Brit. Zool. 
ed. 4, vol. iy. p. 98 (probably). — Donovan, Brit. Shells, vol. 
ii. pl. 63, side figs.— Maron and Rack. Linn. Trans. vol. viii. 
p. 95. 


216 ARCADA. 


Glycimeris argentea, DA Costa, Brit. Conch. p. 170 (in part), pl. 15, f. 6 (on 
the right). 
Nucula margaritacea, LAMARcK, Anim. s. Vert. (ed. Desh.) vol. vi. p. 506 
(chiefly). — Brown, Illust. Conch. G. B. p. 85, pl. 33, 
f. 12. — Puixiepr, Moll. Sicil. vol. i. p. 64, and vol. ii. 
p. 45. 
» nucleus, var. (3. LoveN, Index Moll. Skandinay. (from specimens). 


This very abundant species (at least to the dredger, for 
it is rarely thrown perfect upon the shore) is of a shortened 
subtriangularly ovate form, seldom oblique, moderately con- 
vex, strong in texture, and covered with a dull olivaceous 
yellow, or ashy-olive coloured epidermis, the surface be- 
neath which is of an uniform white, and entirely devoid of 
any coloured rays. The exterior is almost smooth in the 
middle, and on the umbones, but at the sides and base is 
marked with very faint radiating striz, which are occasion- 
ally obscurely decussated by rather strongly marked lines 
of growth and slightly elevated wrinkles. The ventral 
edge is moderately arcuated, and rises rather the more in 
front ; the hinder dorsal edge slopes with but little con- 
vexity, and uniting with the ventral without angulation 
forms a somewhat tapering and bluntly rounded termina- 
tion to the produced posterior side. The front margin does 
not abruptly decline (although the anterior side is still very 
short) in a straight line, but is sinuous, a very obscure 
emargination terminating it below, above which it swells 
out a little, so as to give a sort of pouting appearance to 
the lips of the lunule. This latter, which is only defined 
by a slight retusion of the surrounding surface and the 
absence of radiating striulg, is large and destitute of sculp- 
ture. The hinder dorsal area is a little flattened, and its 
lips bend inward ; it is likewise devoid of all sculpture, or 
marked characteristics. The umbones are not peculiarly 
prominent, nor are the beaks, which curve forward, very 


NUCULA. yA hy 


acute. The inside is nacreous, with usually a bluish cast ; 
the hinge-margin is broad, and provided with about twenty 
teeth behind and about ten in front, which appear to vary 
very greatly in elevation, but are typically very long, and 
most elevated towards the extremities of each series. 

An ordinary-sized individual measured two-fifths of an 
inch in length, and rather more than a third of an inch in 


breadth. 
The animal is shaped like the shell ; and is of a yellowish 


or brownish-white hue. The mantle is open throughout in 
front and posteriorly, not forming any siphons, and having 
its margins quite plain. The foot is white, and as if pedun- 
culated and deeply grooved, so as to expand into a broad 
leaf-shaped disk with serrated margins: by means of this 
organ it can creep like a gasteropod, and we have seen it 
walk up the sides of a glass of sea-water in which we had 
it confined for observation. The structure of the branchie 
and margins of the mouth have been carefully examined by 
Mr. Clark, whose description we prefer: ‘‘ The branchize 
are pale reddish-brown equal rather elongated lamina, two 
on each side, running pretty straight longitudinally and 
hanging parallel to each other, free, plain on their outer 
surfaces, and finely pectinated on the inner. There are 
two labia on each side hanging from the anterior end of the 
branchie, one being very small, like a minute leaf, of a deep 
brown colour; the other white, folded together, with the 
edges scalloped, puckered, or plaited, forming a furrow with 
its open part anterior, and terminating posteriorly in a spiral 
curl, having the extreme point a little cloven; this labium 
is three or four times the size of the smaller. Besides the 
pair of labia in each side there is a long membrane pucker- 
ed, folded together, forming a furrow (like the larger labia) 
on each side the mouth, and running downwards, partially 


VOL. II. EE 


218 ARCADE. 


curling around the anterior muscle, of a pale brown 
colour.” The vibratile cilia of the branchiz are very large. 

It is distributed, often in great abundance, all around 
our shores. It frequents a coarse bottom and rather deeper 
water—from seven to ten fathoms—than its near ally 
nitida (S.H.). It oceurs also, and in sufficient plenty, 
usually on a bottom of gravel or muddy gravel, at much 
greater depths, as twenty, thirty, forty, and even as deep 
as eighty and ninety fathoms (E.F.). It ranges through- 
out the European seas, and occurs fossil in both red and 
coralline crags.* 


N. nitipa, Sowerby. 


Triangular, either rayless, or with the rays linear and dark 
grey ; epidermis highly lustrous ; hinder extremity tapering, its 
dorsal area not sculptured ; inner margin crenated. 


Plate XLVII. fig. 9. 


Arca nucleus, Mont. Test. Brit. p. 14 (chiefly). — Ditiw. Recent Shells, vol. i. 
p- 244 (in part). 

Nucula nitida, SowERrBy, Concholog. Illustrations, Nucula, No. 29, f. 31.— 
Han.ey, Recent Shells, vol. i. p. 171, pl. 19, f. 44. 


So closely does this shel] approach the preceding in 
general features, that in place of recapitulating character- 
istics common to both, we shall merely indicate their 
points of difference. That most immediately perceptible is 
the highly lustrous epidermis of an ashy olive colour, 
beneath which the surface is occasionally adorned with 


* The N. argentea of Brown (Illust. Conch. G. B. p. 85, pl. 33, f. 14, 15.) 
solely constituted from a single valve of little more than a line in length, and said 
to resemble the fry of N. margaritacea, is thus described :— 

“‘ Obliquely ovate, very glossy, and smooth; colour olivaceous ; umbones 
placed much to the posterior side, with a cordiform depression beneath ; inside 
glossy, silvery white; hinge with 12 (!) rather strong, regular, upright teeth ; 
margins with very fine crenulations——Dunbar.” 


NUCULA. 219 


dark grey linear rays. The shape is more triangular, 
being less blunt likewise at the hinder termination. The 
anterior edge is less sinuous, and more abrupt, the lunule 
not being so projecting; and the front basal angulation is 
much more sharply defined. The slope of the hinder 
margin is also more considerable, and the posterior rise of 
the ventral edge more sudden. The valves are thinner ; 
the hinge-margin less broad, and the teeth are not ordina- 
rily quite so produced: the cartilage support, for the most 
part, does not project so far inward, but is more oblique. 
The dimensions are very slightly less than in the species 
with which we have been comparing it. 

No distinctions have as yet been detected between the 
animal of this and the last species. 

Everywhere on the south coast, always in shallow water 
in sand(S.H.); Dartmouth, in twenty-seven fathoms, sand, 
eight miles from shore (M‘Andrew and EH. F.); Oxwich 
Bay, near Swansea, in sand at low-water mark, Fishguard 
and Manorbeer (Jeffreys); Lundy Island, in seven to 
twenty-eight fathoms (M‘Andrew); Tenby (S.H.); Scar- 
borough (Bean); on the Northumberland and Durham 
coasts, in deepish water and thrown up in sand, rather 
rare (Alder). In many localities of the Hebrides (Jeffreys, 
Barlee). Var. “erosa,” Jeffreys, at Oban. Dealvoe, 
Zetland (Jeffreys); Moray Firth, in thirty-four fathoms 
(M‘Andrew); Dundalk, Portmarnock, and Youghal, in 
Ireland. (W. Thompson). Off Cape Clear, in thirty 
fathoms (M‘Andrew). 

Loven records this species as an inhabitant of the shores 


of Sweden. 


220 ARCADA. 


N. raprata, Hanley. 


Elongated-trigonal, with rufous rays ; epidermis but slightly 
glossy ; hinder extremity tapering, its dorsal area not sculptured ; 
inner margin crenated. 


Plate XLVII. fig. 4, 5, and XLVIII. fig. 7. 


Arca nucleus, PULTENEY, Hutchins, Hist. Dorset, p. 35. Marton and Rack. 
Dorset Catalog. p. 37,.—Turton, Conch. Diction. p. 8, f. 1, 2. 
Nucula nucleus, Turt. Dithyra Brit. p. 176, pl. 13, f. 4. — Brit. Marine Conch. 
p. 105, f. 74.—Macertiiv. Moll. Aberdeenshire, p. 243. 
»  nuclea, FLEMING, Brit. Anim. p. 401. 
»  margaritacea, BLAINVILLE, Manuel’ de Malacologie, pl. 65, f. 5 (not 
well). —Sowxrsy, Conch. Manual, f. 137. 


This elegant Nucula is almost exactly the shape of an 
elongated nitida, that is to say, far more triangular in 
contour, and far more attenuated posteriorly than in 
nucleus. Its valves are strong and are more compressed 
than in either of the shells referred to. From the former of 
them its scarcely glossy epidermis (the olivaceous hue of 
which is modified in different individuals by tints of yellow- 
brown or even green), from the latter the chestnut rays 
which adorn the exterior and vary as to width and 
number (sometimes there are additional radiating lines of an 
iron-grey, and occasionally these alone are present) effec- 
tually distinguish it. In all stages of growth it preserves 
its peculiar distinctive features. The swell of the ventral 
margin is more gradual than in nucleus, its posterior dorsal 
slope more considerable; its mternal nacre of a less blue 
cast and rather more iridescent, and its teeth are in general 
not quite so elongated. In other respects our description 
of nucleus is equally applicable to the present species. It 
exceeds that shell however in dimensions, as it attains to 
at least five-eighths of an inch in length, and nearly half an 


NUCULA. 221 


inch in breadth. When of these dimensions, the front 
declination is so abrupt (and almost rectilinear) that the 
beaks are all but perfectly terminal. 

The remark made respecting the animal of Nucula 
nitida equally applies to this. 

This species is probably widely distributed, but having 
been usually confounded with nucleus, it is difficult to ascer- 
tain its precise range. Certain localities are South Devon, 
Torbay (Alder and S. H). Milford Haven, in ten 
fathoms, always in separate parts of the bay from nucleus 
(M‘Andrew and E. F.) ; Lundy Island, seven to twenty- 
five fathoms in sandy-gravel (M‘Andrew). Lamlash, 
Arran (Alder); and, probably, Exmouth (Clark). Mr. 
M‘Andrew has taken this form at Gibraltar. 


N. vecussata, Sowerby. 


Solid, decussated ; hinder dorsal area barred with wavy plici- 
form wrinkles. 


Plate XLVIL. fig. 1, 2, 3. 


Nucula decussata, SowERBY, Concholog, Illust. Nucula, No. 27, fig. 18.—HANL. 
Recent Shells, yol. i. suppl. pl. 20, f. 8. 
»  sulcata, Bronn, Italiens Tertiar-gebild. p. 109 (inadequately). — 
Purwiprr, Moll. Sicil. vol. ii. p. 45; Wiegmann’s Archiy. 
Naturg. 1845, p. 192, pl. 7, f. 24, 25. 
Polii, Puitirs, Moll. Sicil. vol. i. p. 63, pl. 5, f. 10. —Jzrrreys, Ann, 
Nat. Hist. vol. xix. p. 313, 


”° 


The general aspect of this shell is not unlike that of 
nucleus, to which its outline is very similar. It resembles 
that shell much more nearly than it does either nitida 
or radiata, owing to the existence of an anterior side, the 
beaks being far less nearly terminal in the present than in 
the three preceding species. It is, however, slightly more 


222 ARCADA. 


elongated, rather more tapering behind, and has the base of 
the anterior side somewhat more prominent, in consequence 
of the less abrupt slope of the front margin. It is a solid, and 
occasionally (for its size) even a heavy shell, never rayed with 
coloured streaks, but covered with an epidermis of a dirty 
or greenish oil colour. The surface, except upon the dorsal 
areas, is closely and finely decussated by raised radiating 
striule and rather irregular elevated concentric wrinkles ; 
which latter are most perceptible towards the base and 
sides, being sometimes almost obsolete upon the central 
disk. The lunule is large, pouting, and well defined by 
that abrupt cessation of convexity, which preceding the 
retusion that bounds it, more or less sharply angulates the 
shell. The hinder dorsal area is rather flattened, and is 
transversely corrugated by rather closely disposed pliciform 
wrinkles, which are not at all oblique, and are always more 
or less undulated. Similar, but more interrupted or even 
subgranose ones, usually adorn the lunule likewise. The 
umbones are moderately prominent, and are placed at 
nearly one-third the distance from the anterior extremity ; 
they are frequently eroded in the adult examples. The 
internal nacre is pearly white; the margin crenulated 
within; the cartilage small; the hinge-margin by no 
means broad, and furnished with about twelve teeth in 
front and twenty-four behind, none of which are especially 
elongated. This proportion of front and hinder teeth 
appears to be very general in the Vucule. 

For its genus, it must be regarded as a large shell, one 
of our examples measuring five-eighths of an inch in 
breadth, and all but four-fifths of an inch in length. 

The animal appears to resemble closely that of nucleus. 

This fine and very distinct species was announced as 
British by Mr. Jeffreys, in the nineteenth volume of the 


NUCULA. 273 


“ Annals of Natural History.” Although an inhabitant of 
the deeps of the Mediterranean, it is probably a Nucula of 
northern origin. On our coasts it has been taken alive in 
thirty and forty-five fathoms, dark muddy bottom, off Raza 
in the Hebrides, and north of that island in one hundred 
and fifty fathoms, but dead; also in one hundred fathoms 
in Loch Fyne (M‘Andrew and E.F.). Mr. Barlee has 
taken it at Oban, and at Tarbert in Loch Fyne. Mr. 
Clark and Mr. Warren have taken it in Dublin Bay, and 
it has been also dredged on the south-west coast of Ire- 
land (M‘Andrew). 

Lovén records it as a Swedish shell. It occurs fossil in 
the Pleistocene Tertiaries of Italy, and living at great 
depths in the Aigean. 


N. tenuis, Montagu. 


Abbreviated-ovate, fragile, compressed ; inner margin not cre- 
nated. 


Plate XLVII. fig. 6, and (Animal) plate P. fig. 5. 


Arca tenuis, Mon’. Test. Brit. Suppl. p. 56, pl. 29, f. 1—Turr. Conch. Diction. 
p. 11.— Dititwyn, Recent Shells, yol. i. p. 246.— Index Testa- 
ceolog. pl. 10, Arca, f. 45. 

Nucula ,, Turr. Dithyra Brit. p. 177.— Fie. Brit. Anim. p. 402.— Mac- 
eiiyv. Moll. Aberd. p. 244. — Brit. Marine Conch. p. 105. — 
Brown, Illust. Conch. G. B. p. 85, pl. 33, f. 13.—Goutp, Invert. 
Massach. p. 105.— Hannu. Recent Shells, vol. i. p. 171, pl. 10, 
Arca, f. 45. 

Nucula tenera (fossil), Woop, Mag. N. Hist. 1640, pl. 14, f. 2. 


This, by far the most fragile and depressed of our British 
Nucula, is also less triangular in its outline than the mass 
of its congeners, having its contour, which varies greatly in 
extent of obliquity, of a more or less abbreviated ovate 


224 ARCADE. 


form. Its valves are much compressed, thin, brittle, and 
almost semitransparent, smooth, with the exception of the 
presence of a few growth lines, and covered with a highly 
lustrous epidermis, which varies in hue from olivaceous 
yellow to yellowish drab or ash colour, but is not rayed or 
variegated in any individuals we have met with. The 
sides are, as usual, extremely unequal, and the ventral 
edge, which is not crenated internally, greatly arcuated. 
The anterior edge is more or less straight and abrupt; the 
hinder edge at first rather ascends than declines, so that a 
more or less subangulated curve prevents a continuity and 
abruptness in the slope; hence the posterior termination is 
not subcuneiform, or much attenuated, but simply, though 
not broadly, rounded. The greatest breadth of the shell is 
a little before the middle, and not immediately behind the 
umbones. The hinder dorsal area is not flattened, so that 
the lips project rather than incurve; there is no sculpture 
either there or on the site of the lunule, which latter is but 
seldom at all defined. The umbones are not prominent ; 
the beaks are small, but acute and distinct. The internal 
nacre is silvery white, and in general not remarkably bril- 
liant ; the edge is entire ; there are about six teeth before 
the cartilage-pit (which is extremely oblique), and fifteen 
behind it. The Greenland specimens are described by 
Moller as having twelve anterior and sixteen posterior 
teeth! (Ind. Moll. Groenl., p. 17.) One of our larger 
examples measured four-tenths of an inch in length, and 
one-fourth less in breadth. The younger individuals are 
more elongated in proportion. 

The animal is white: the margins of its mantle are quite 
free in front and posteriorly, and simple at edge. The 
foot is white, rather more elongate, and not so markedly 
pedunculated as in the other British Nucule, nor are the 


NUCULA. 225 


margins of its disk so coarsely serrated ; crenations are, 
however, more numerous. 

This is essentially a Northern species, and common only on 
the coasts of Scotland, and the north-east of England. It 
inhabits deep water on muddy or sandy bottoms, and is a 
favourite food for haddocks. The most southern locality 
of which we have a note is “Tenby,” communicated by 
Mr. Jeffreys, on the authority of Dr. Goodall. The only 
other English localities are Scarborough (Bean), and the 
coast of Northumberland, where it is frequent in the coral- 
line zone (Alder). In Scotland it occurs in the Clyde 
district, and the Hebrides in many localities, where we have 
taken it alive in depths from forty to one hundred 
fathoms: also in Zetland in sixty and eighty fathoms 
(M‘Andrew and E. F.) 

The more trigonal and convex variety has been taken by 
Mr. Jeffreys in one hundred fathoms, fifty miles east of 
Lerwick, and ten miles from the same part of Zetland in 
fifty fathoms. ‘‘ Alive in forty fathoms, fine sand, about 
five miles off the Ord Head, Caithness, associated with 
Virgularia, Solen pellucidus, Montacutea, Lucina flexuosa, 
&e” (Thomas). Capt. Laskey found it off the entrance 
of the Frith of Forth in considerable numbers. In Ireland 
it has been taken at Portmarnock, near Dublin, by Mr. 
Warren. 

This shell appears first as a fossil in the red crag, and 
occurs in the mammaliferous crag of Southwold (S. V. 
Wood), and the pleistocene beds of the Clyde (Smith), and 
Ireland (E. F.). It distribution as a living species is ex- 
tensive, ranging through the Boreal and Arctic seas, and 
round to the coasts of Massachusetts. 


VOL. If. G G 


226 ARCADZ. 


LEDA. ScHUMACHER. 


Shell equivalve, inequilateral, oblong, produced posterior- 
ly, closed, smooth or concentrically striated, invested by 
an epidermis; margins smooth; beaks approximated, in- 
curved ; inside more or less nacreous ; hinge-line angulated 
and formed, as well as the ligament, as in Nucula. Pallial 
impression with a sinus. 

Animal oblong; mantle open in front, with simple or 
fimbriated margins, furnished posteriorly with two partially 
united slender unequal siphonal tubes. Foot and palps 
like those of Nucula. 

The propriety of separating this group of bivalves from 
Nucula was first shewn by the lamented author of the 
“Index Molluscorum Groenlandiz,” who, after having 
discovered the peculiarities of the animals, adopted the 
genus as empirically proposed by Schumacher. It is 
singular that the sinuated pallial impression, indicative of 
the presence of siphonal tubes, had previously escaped 
notice. Leda is one of several instances which go to shew 
the fallacy of separating the lamellibranchiate bivalves into 
great sections on account of the presence or absence of 
siphons. The genus ranges far back in time, and its species 
exhibit similar habits with those of Nucula. 


L. caupata, Donovan. 


Surface girt with raised concentric stri. 


Plate XLVII. fig. 11, 12, 13, and (Animal) plate P. fig. 2. 


Arca minuta, O. Fasricius, Fauna Groenlandica, p. 414 ? — Monr. Test. Brit. 
p- 140.—Maron and Rack. Linn. Trans. vol. viii. p. 92.—Dor- 
set Catalog. p. 36, pl. 1, f. 16. — Turr. Conch. Diction. p. 11, 
f. 98.— Ditiw. Recent Shells, vol. i. p. 245. — Index Testa- 
ceolog. pl. 10, Arca, f. 44. 


LEDA. Piva 


Arca caudata, Donoy. Brit. Shells, vol. iii. pl. 78. 
Nucula minuta, Tur. Dithyra Brit. p. 178.— Fie. Brit. Anim. p. 402.— 
Macei.1i1yv. Moll. Aberd. p. 245.—Brit. Marine Conch. p. 106. 
— Browy, Illust. Conch. G. B. p. 84, pl. 33, f. 18. — Hann. 
Recent Shells, vol. i. p. 168, pl. 10, Arca, f. 44. — (No. 
Philippi, Moll. Sicil.; scarcely Gould, Invert. Massach.). 
» rostrata, Maceitity. Moll. Aberd. p. 245 (not Montagu). 
Leda minuta (and complanata), MéiLER, Index Moll. Groenl. p. 17 ? — Kine, 
Ann. Nat. Hist. vol. xviii. p. 240. 
» caudata, LovEN, Index Moll. Skandinay. p. 34 (probably). 


Of the two very distinct forms of this graceful shell, that 
which we regard as the typical one is oblong-lanceolate in 
shape, compressed at the longer side, and but little convex 
at the other; the central disk is not, however, particularly 
shallow. The valves are decidedly inequilateral, opaque, 
moderately strong, and covered with a rather dull epidermis 
of a yellowish or pale olive-green; their surface is adorned 
with numerous regular concentric delicate lyre (or raised 
striz), which are much narrower than their simple inter- 
stices. These stria, which vary much in strength and 
distance, are sometimes much elevated, sometimes rather 
depressed. This sculpture uninterruptedly and almost 
evenly occupies the entire exterior, the lunule and the 
immediate vicinity of the opposite dorsal suture alone ex- 
cepted. The ventral edge is gently arched at the shorter 
side, where its upward sweep exceeds the descending 
curve of the dorsal margin, which it surpasses, or at least 
vies with in convexity ; hence causing the most projecting 
portion of that side to lie either in the middle or above it, 
and the tapering but rounded extremity to become occasion- 
ally a little angulated. It is straighter at the longer side 
and by its ascent (through trifling), and by its slight sub- 
terminal retusion, assists the incurved and but moderately 
sloping dorsal edge in forming a rather long subcentral 
rostrum, which latter is much attenuated, and somewhat 


228 ARCADE. 


squarely truncated at the tip. The lunule is large, con- 
cave (but with pouting lips), spindleshaped, and devoid of 
all sculpture; it is well defined by the sharply angulated 
upper edge of the flattened umbonal fold, which likewise 
exhibits an angulation, though a less marked one, at its 
lower edge, where its bounds are clearly indicated by 
the abrupt flexure of the girding lyre. The beaks which 
are situated at about three-sevenths of the distance from 
the rounded extremity are acute, prominent, and only 
slightly inclined to the longer side. The inside is of 
a polished white (not nacreous) which has almost invari- 
ably a bluish cast; the cartilage-pit is appressed; there 
are about eighteen vaulted spinous teeth on the longer 
side, and about sixteen on the other; the margin is quite 
plain. 

The other (or northern) variety, generally a smaller 
shell, being of a more convex and abbreviated shape, has 
consequently its lower margm more arched, and its rostrum 
more sudden in formation. Some very delicate and obscure 
radiating lineoles are almost invariably perceptible; the 
sides are also more unequal; and the strize, which are 
usually finer and more crowded, do not quite extend to 
either extremity. In the more characteristic examples, 
the swell of the ventral edge is very unequal, and not 
gradual as in the typical variety. Were these features 
permanent in every individual, they might be probably 
estimated as of specific importance; but as we have 
examples before us which unite the exact shape of the 
previous form, to the radiating lineoles, &c., of this one, 
we cannot venture to consider the two shells as more than 
varieties of the same species. 

The length of a large specimen was two-thirds of an 


inch ; its breadth was four lines and a half: the ordinary 


LEDA. pap 


size of individuals is rarely above half an inch long, and 
rather more than half that measurement broad. 

The description by Fabricius of his Arca minuta, drawn 
up solely from two engorged, and probably eroded, indivi- 
duals, fairly enough agrees, except in the number of teeth, 
with our British species ; the shell, however, identified with 
it by the Northern conchologists, who naturally have better 
data for determining the Boreal species, than we possess, is 
allied, but very distinct. 

Animal of a white colour, oblong and pyriform ; the 
margins of the mantle are freely open except posteriorly, 
and are fringed or denticulated by a series of five very 
short filaments. The siphons are united for more than half 
their lengths, considerably prolonged, slender and smooth : 
the branchial one is shorter than the anal, and the latter 
has a quadrangular orifice with apiculated angles. The 
foot is oblong, compressed, white, deeply grooved, and 
capable of expansion into a creeping disk, with crenated 
margins. 

This species, though found in the south, is rare there, 
and becomes plentiful only on our northern coasts. Herm, 
Sandwich, Weymouth, but scarce (S. H.); Exmouth, 
in twenty fathoms, very rare (Clark); Tenby (S. H.) ; 
Fishguard (Jeffreys) ; ten fathoms, Milford Haven, twenty- 
five fathoms Anglesey, and fifteen to twenty fathoms, 
gravel, Caernarvon Bay (M‘Andrew and E. F.); Scar- 
borough (Bean) ; from deepest water, frequent on the 
coasts of Northumberland and Durham (Alder) ; through- 
out the Hebrides and Clyde district in various depths of 
water, from fifteen to ninety and one hundred fathoms. 
Off the Mull of Galloway (Beechey); and Sana Island 
(Hyndman); in deep water on the East coast from the 
Dudgeon to Orkney (Thomas). 


2340 ARCADE. 


The longer beaked variety occurs on both sides of Scot- 
land, as in Loch Fyne (Barlee) ; and Aberdeen (Mac- 
gillivray). 

This shell ranges through the Scandinavian and Arctic 
Seas, and is found fossil in our Pleistocene strata, but not 


commonly, and occurs in the red crag of Sutton (S. V. 
Wood). 


L. pyomma, Munster. 


Minute ; surface quite smooth. 


Plate XLVII. fig. 10, and (Animal) plate P. fig. 3. 


Nucula pygmea, MinsTER in Goldfuss. Pet. Germ. pl. 125, f. 17 (fossil). — 
Putspri, Moll. Sicil. vol. ii. p. 46 (fossil) —S. Woop, Mag. 
Nat. Hist new series, vol. iv. p. 298, pl. 14, f. 7 (fossil). 
» tenuis, PuitipPi, Moll. Sicil. vol. i. p. 65, pl. 5, f. 9 (fossil). 
»  gibbosa, Smiru, Wern. Mem. vol. viii. pl. 2, f 10 (fossil). 
»  lenticula, MOLLER, Index Moll. Groenlandiz, p. 17 (from types). 
Leda pygmea, ForBEs, Mem. Geolog. Survey, vol. i. p. 419. 
» tenuis, JEFFREYS, Annals Nat. Hist. vol. xix. p. 313. 
Yoldia pygmea, LovEN, Index Moll. Skandinay. p. 35. 


This minute shell, one of the more recent additions to 
our Fauna, was first incidentally recorded as a living inha- 
bitant of our seas in the “ Memoirs of the Geological Sur- 
vey of Great Britain.” 

It is of a triangular-oval shape, subequilateral, more or 
less ventricose (especially near the umbones), not particu- 
larly thin, quite smooth, and covered with a very pale 
yellowish olive-coloured and highly lustrous epidermis. 
The ventral margin is gently but decidedly arcuated, 
ascending in a convex line at both extremities, but rather 
the more so at the longer side, with whose upper edge it 
forms a short and subrostrated extremity, of which the tip 
is bluntly acuminated. This portion is not beaked in the 


LEDA. 23 


young, but simply attenuated and rounded. The extremity 
of the opposite side, which is rather the shorter and some- 
what tapering, is unsymmetrically rounded; the upper 
edge, except near the very prominent umbones, is convex 
and moderately sloping. The declination of the other 
dorsal edge is likewise but moderate, its general inclination 
is retuse; in the young, however, it is even slightly con- 
vex. The beaks are small and inflected, scarcely inclining 
to the longer side. There is not even a rudimentary lunule, 
and the opposite dorsal area is neither impressed nor flat- 
tened. There are about a dozen teeth on each side of the 
hinge-margin; the cartilage pit is very small: the inner 
margin quite entire. 

Few specimens much exceed a fifth of an inch in length, 
and a full eighth of an inch in breadth. 

The animal is ofa pale fawn-white colour. The margins 

of the mantle are freely open in front, closed posteriorly to 
form a short tube consisting of the united siphons, of which 
the branchial appears shortest: the orifices of both are 
plain. The foot is hatchet-shaped and wide-grooved at its 
posterior edge, to form an expanded and crenated disk. 
_ The discovery of this interesting little Leda as a living 
inhabitant of the British seas, is due to Mr. M‘Andrew, 
who dredged it first in the Sound of Skye on a muddy 
bottom, twenty-five to forty fathoms deep; off Croulin 
Island in thirty fathoms; and in fifty fathoms in the 
Minch. It has since been taken off Skye by Mr. J eftreys 
and at Portree, Mr. Barlee, and by the latter gentleman 
at Stornoway in the Outer Hebrides. 

Loven finds it on the Scandinavian Coast from Bohuslan 
to Finmark; and Moller, who first noticed it as a living 
species, discovered it in the Greenland Seas. As a fossil it 
has been better known; occurring in the Newer Pliocene 


232 ARCADE. 


of Sicily, and other places abroad, and in the Clyde Pleis- 
tocene beds, where it was observed by Mr. Smith of Jor- 
dan- Hill. 


SPURIOUS. 


L. Monracui, Gray. 


Arca rostrata, Mont. (not Chemn. Dillw. nor Brug.) Test. Brit. Suppl. p. 55, 
pl. 27, £ 7.—Turr. Conch. Diction. p. 11. 

Nucula ,, Turr. (not Lam.) Dithyra Brit. p. 178.—F em. Brit. Anim. p. 
402. — Brit. Marine Conch. p. 106. — Brown, Illust. Conch. 
G. B. p. 84, pl. 33, f. 16.— Han. Recent Shells, vol. i. p. 168, 
suppl. pl. 20, f. 1. 

Montagui, Gray, Ann. Philosoph. 1825, p. 138. 

curvirostrad, SOWERBY, Concholog. Ilustr. Nucula, f. 5.—REEVE, Conch. 

Systematica, pl. 85, f. 5. 
recurva, CONRAD, Journ. Acad. Nat. Sci. Philadelphia, vol. yi. pt. 2, 
p. 262, pl. 11, f. 21—Hant. Recent Shells, vol. i. p. 170. 


A native of Liberia, &c.; introduced by Montagu, as dredged 
in Scotland of St. Abb’s Head, by Mr. Laskey. Probably from 
ballast. 


In consequence of the Pleistocene Tertiary beds of clay 
on the west coast of Scotland being often laid bare below 
low-water mark, fossil shells are frequently brought up in 
the dredge along with recent ones, and as often cast on the 
shore. Owing to their extremely fresh aspect, even the 
epidermis in many instances being preserved with its pris- 
tine colours and lustre, it is very difficult to say at a glance 
whether such specimens be not the exuvia of animals yet 
living in the neighbourhood. This difficulty is yet further 
increased by the possibility which always exists of the 
species in question yet lingering alive (as indeed we have 
seen in the case of Leda pygmea), in some limited tract or 
Boreal patch in our seas. Until, however, such is proved 


ARCA. Da 


to be the case, we cannot admit well known and character- 
istic drift species into our list of living forms, and in this 
category we must place Leda oblonga (Nucula oblonga, 
Brown, Ill. Conch. G. B. p. 84, pl. 33, f. 1) and Leda 
truncata (Nucula truncata, loc. cit., p. 84, pl. 38, f. 1), 
both of which are, however, still found living in Arctic 
regions. 


ARCA. LINNzUs. 


Shell more frequently equivalve, more or less inequila- 
teral, closed or gaping in front, more or less quadrate, 
usually solid, almost always radiatingly ribbed or striated, 
covered with an epidermis, which is in most instances 
loose and rough; margin smooth or crenate ; beaks remote, 
separated by a tetragonal grooved ligamental area. Hinge 
straight or nearly so, consisting of small interlocking teeth, 
parallel in the centre, oblique at the sides: ligament ex- 
ternal. fPallial impression entire, muscular scars very 
marked, and sometimes ledge-shaped. 

Animal oblong, mantle freely open, simple or fringed ; no 
siphons. Foot large, oblong, bent, grooved throughout its 
length, so as to form a disk with plain or slightly crimped 
margins; a byssal gland at its base. Byssus compact. 
Mouth surrounded by labia formed out of the extremities 
of the branchiz ; no true palps. 

The Arks, so called from their boat-like shapes, are 
mostly dwellers in crevices of rocks and cavities of shells, 
moored by their powerful byssus, but can equally live free. 
They are found in all depths of water, though the majority 
of species are littoral. The genus has most representatives 
in the Tropics. M.Nyst, who has recently catalogued both 
the existing and extinct forms of Arca, enumerates nearly 


VOL, II. H H 


234 


ARCADA. 


460 species. They range in time as far back as the 
Silurian epoch. We regard Cucullea and Byssoarca as 


scarcely sections of the genus. 


A. rerracona, Poli. 


More or less stained with brown ; umbonal ridge sharply angu- 


lated 


; ligamental area rhomboidal. 


Plate XLV. fig. 9, 10, and (Animal) plate P. fig. 1. 


2 Area tortuosa, PENNANT (not Linn.), Brit. Zool. ed. 4, vol. iv. p. 97. 


99 


99 


Noe,* Monv. (not Linn.), Test. Brit. p. 139, pl. 4, f. 3.—Donov. Brit. 
Shells. vol, 5, pl. 158, f. 1, 2. —Coucu, Cornish Fauna, pt. 2. 
p. 30.—Brown, Ill. Conch. G. B. p. 86, pl. 33, f. 1, 2, 3. 
fusca, DoNovaN (not Brug.), British Shells, vol. v. pl. 158, f. 3 (not 4). 
— Mont. Test. Brit, Suppl. p. 51.—Turvr. Conch. Diction. 
p- 10; Dithyra Brit. p. 166.— Fiemine, Brit. Anim. p. 397. 
— Covcu, Cornish Fauna, pt. 2, p. 30. — Brit. Marine Conch. 
p. 101.—Brown. Ill. Conch. G, B. p. 86, pl. 33, f. 4, 5. 
tetragona, Pout, Test. Sicilize, vol. ii. p. 137, pl. 25, f. 12, 13. — Turr. 
Dithyra Brit. p. 166, pl. 13, f. 1. — Fiemine, Brit. Anim. 
p- 398."— Forges, Malac. Monensis, p. 41, pl. 3. — Brit. 
Marine Conch. p. 102. — Brown, Ill. Conch. G. B. p. 86, 
pl. 33, f. 20, 21.—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. 
p- 461. — Puiirri, Moll. Sicil. vol. i. p. 57. — Han. Re- 
cent Shells, suppl. pl. 19, f. 13. — RrxEve, Conch. Iconica, 
Arca, pl. 15, f. 100. 
imbricata, DILLWYN (not Brug.), Recent Shells, vol. i. p. 226 (chiefly). 
Cardissa, LAMARCK, Anim. s. Vert. (ed. Desh.) yol. vi. p. 463.— ALDER, 
Cat. Moll. Northumb. and Durh. p. 79. — DELEssERT, Re- 
cueil Coq. Lam. pl. 11, f. 14. —Hanu. Recent Shells, vol. i. 
p. 153. 


papillosa, Brown, Wern. Mem. vol. viii. pl. 1, f. 19. 


* The Arca Noe of Dr. Turton, with “chestnut bands crossing the valves 
diagonally ” (Conch. Diction. p. 9, and Dithyra Brit. p. 166.—F Lem. Brit. Anim. 
p- 397.—Brit. Marine Conch. p. 101), is not identical with this shell, but agrees 
rather with the veritable Noe (Pout, Test. Sicil. vol. ii. p. 128, pl. 24. — Dzsn. 
Exp. Se. Algiers, Moll. pl. 120, anatomy) of Linnzeus, whose description in the 
* Museum Ludovice Ulrice”’ is reprinted verbatim by Maton and Rackett, in 
their “ Descriptive Catalogue of British Shells” (Linnean Transactions, vol. viii. 


p- 91). 


It is not indigenous. 


ARCA. 255 


Arca navicularis, Dusu. (not Brug.) Anim. s. Vert. (ed. Desh.) vol. vi. p. 462. 
—Puuert, Moll. Sicil. vol. ii. p. 42. 
» Britannica, Rexve, Conch. Icon. Arca, pl. 15, f. 98. 
» rhombea, Coucn, Cornish Fauna, pt. 2, p. 31. 


It is but rarely that we meet with this Arca in fine and 
perfect condition; much more frequently it occurs only in 
single valves, or, from the nature of its dwelling-place, with 
a considerable portion of its surface abraded. In this last 
state it has been separated by Turton from its more typical 
form (the fusca of Donovan) under the name tetragona ; 
whilst aged and worn examples have been confounded with 
the true Noe by Montagu and Donovan. 

Its valves, which, although broad across the umbones, 
where the surface is much flattened, rapidly diminish in 
convexity, are of an elongated subrhombic shape, strong 
and opaque, devoid of lustre, and of equal size and pro- 
fundity. They are of a warm rufous brown or reddish 
chocolate colour, with the colouring matter not evenly 
diffused, but wholly or partially absent near the front of 
the shell, and disposed in darker concentric zones upon the 
hinder portion. In the more beautiful specimens the ante- 
rior third is almost white, with, however, a more or less 
distinct radiating brown stain in front. The surface is 
everywhere adorned with most closely arranged radiating 
costelle, which are decussated by still more closely-set 
concentric and somewhat imbricated granules: the inter- 
stices of the costelle, which are of equal size throughout 
the entire exterior (the few, however, which immediately 
follow the umbonal keel become changed into radiating 
strie), are so narrow, except near their termination, as 
almost to be linear, and are clothed with a brownish and 
somewhat squamular epidermis. The umbonal ridge is 
sharply angular, and upon its crest the decussation becomes 


almost squamular, and the epidermis of an increased 


236 ARCADA. 


length ; the triangular area beyond it is concave and nar- 
row, and the terminal costelle lie rather further apart than 
the rest. The anterior side is decidedly short, its upper 
corner is angular (the angle is generally almost a right one), 
the lower extreme of it is obliquely rounded, the inclination 
of both anterior and posterior edges being oblique and 
backward. The hinder termination is biangulated, the 
upper corner being an obtuse, the lower an acute, angle. 
The ventral margin usually displays but little hiation in 
the young, wherein it is usually nearly rectilinear, but in 
the more aged individuals the gape is often of extreme 
magnitude; in both the inclination is almost rectilinearly 
ascending at the longer end. The ligamental area is more 
or less concave, although projecting a little at the suture : 
it is of a pale buff colour, so lineated with brown as to form 
closely disposed obtuse angles at the suture : the actual area 
occupied by the brownish ligament is small and rhomboidal 
in outline: in the younger examples it distinctly exhibits 
an intervening central space, which diminishes in its rela- 
tive proportion as age advances. The beaks are acute, very 
far apart, and much inclined. The interior is white, or 
faintly stained with the external colouring: the teeth of the 
shorter portion of the hinge-margin are oblique, and rather 
large ; upon the longer side they are more numerous and 
crowded, less oblique, and more curved. 

We have examined British specimens of this species 
alive, and have had the benefit of ample notes on its struc- 
ture by Mr. Clark and a drawing of it, which we engrave, 
by Mr. Alder. 

The animal is shaped as the shell, and of a firm sub- 
stance; its mantle is open throughout with plain margins, 
except at the posterior extremity where they are dentated. 


There are no siphons, but temporary openings can be form- 


ARCA. yp 


ed by bringing together the edges of the mantle-lobes in 
the branchial and anal regions. The mantle varies in 
colour, either white or brownish’ or orange or yellow, and 
has about forty equidistant black dots, obsolete anteriorly, 
ranged along its edge. The foot is long, narrow, geni- 
culated towards its base, and deeply-grooved, so as to form 
a disk throughout its length, especially in the region of the 
byssal groove: it is usually, as well as the body, of a flesh- 
colour, sometimes yellowish-white. The byssal groove is 
ample and forms a mould for the filamentous matter, which 
is cast in shape of a thin cup-shaped membrane, eventually 
forming a thick and firm brown operculum, which on being 
closely examined is found to consist of the combined byssal 
threads. This operculum can be cast off and reformed with 
great rapidity. The branchie are brown, long, and nar- 
row; their outer surfaces are less striated than the inner. 
“There are no palps, strictly so called; but the linear 
branchie, without terminating as usual, are continued in 
the same narrow form around the buccal orifice, and meet 
with their fellows on the other side, and thus form a pair 
of true labia, rather than palpi” (Clark). 

This fine Ark was once esteemed a very rare British 
shell, but has of late years been found in numerous locali- 
ties all round our coasts. It is taken in crevices of rocks, 
in chinks of old shells, in the interior of dead shells, and 
sometimes quite free; when found in confined localities it 
is often much distorted, but free specimens are very regular. 
It is most abundant on the south-west coast of England, 
the south and west of Ireland, and off the Zetlands. The 
following selected localities will illustrate its range, in the 
living state: Herm, near Guernsey, on dead oysters (S. H.); 
Exmouth on oysters from deep water (Clark); in crevices 
of rocks, Falmouth (Cocks); Penzance, in twenty fathoms 


238 ARCADE. 


(M‘Andrew and E. F.); Fishguard, in twenty fathoms 
(Jeffreys); and off Lundy Island, in twenty-seven fathoms 
(M‘Andrew); Isle of Man, in twenty-five fathoms (E. F.) ; 
frequent in cavities of stones and shells from deep water, 
north of Northumberland (Embleton) ; rare at Scarborough 
(Bean); Berwick (Jchnston) ; thirty-five fathoms, Buchan- 
ness, and Staples; seventeen fathoms, Eda Sound, Orkney 
(Thomas); twelve fathoms, Orkney; Zetland, in twenty- 
five and fifty fathoms, and off Cape Wrath, in fifty-five 
fathoms (M‘Andrew and E. F.). 


A. tactea, Linnzeus. 


White ; umbonal ridge blunt; teeth numerous. 


Plate XLVI. fig. 1, 2, 3. 


LisTeR, Histor. Conch. pl. 235, f. 69. 
Arca lactea, Linn. Syst. Nat. ed. 12, p. 1141.—Da Costa, Brit. Conch. p. 171, 
pl. 11, f. 5.—Donov. Brit. Shells., vol. iv. pl. 135.—Monr. Test. 
Brit. p. 138.— Maron and Rack. Trans. Linn. Soc. vol. viii. p. 
93.— Dorset Catalog. p. 36, pl. 11, f. 5. — FLEmine, Brit. Anim. 
p- 898.—Brit. Marine Conch. p. 102.—Brown, Ill. Conch. G. B. 
p- 86, pl. 33, f. 6. — Dittwyn, Recent Shells, vol. i. p. 236. — 
Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 467. —Mawe, Linn. 
Syst. Conch. pl. 13, f. 4.— Costa, Cat. Test. Sicilie, p. 46. — 
Puitipri, Moll. Sicil. vol. i. p. 57, and vol. ii. p. 42.— HAnt. 
Recent Shells, vol. 1. p. 154, pl. 9, Arca, f. 24. — Renvex, Conch. 
Iconica, Arca, pl. 17, f. 116. 
» arbata, PENNANT (not Linn.), Brit. Zool. ed. 4, vol. iv. p. 98, pl. 58, f. 59. 
»  modiolus, Poi, Test. Siciliz, vol. ii. p. 137, pl. 25, f. 20, 21. —Cosra, 
Cat. Test. Sicilize, p. 45. 
»  crinita, PULTENEY, Hutchins, Hist. Dorset, p. 35. 
» perforans, Turt. Conch. Diction. p. 9 ; Dithyra Brit. p. 169, pl. 13, f 2, 3. 
» Gaimardi, PAYRAUDEAU, Cat. Moll. Corse, p. 61, pl. 1, f. 36 to 39.— 
Desu. in Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 476. — 
Costa, Cat. Test. Siciliz, p. 46.— Hani. Recent Shells, 
vol. i. p. 155.—DeEsu. Exp. Sc. Algiers, Mollus. pl. 124, f. 8 
to ll. 
»  Quoyi, PAYRAUDEAU, Cat. Moll, Corse, p. 62, pl. 1, f. 40 to 43. 


ARCA. 2g 


As Dr. Philippi correctly observes, this is a peculiarly 
variable shell, the chief difference of contour being effected 
by the convexity or straightness of the hinder margin. In- 
dividuals of the former shape (var. Quoyi), are generally 
more compressed when young, are more or less distinctly 
biangulated posteriorly, and have their radiating strie 
finer and more closely disposed ; examples of the latter 
form (var. Gaimardi) are usually more abbreviated in 
shape, and have their beaks more approximate, their epi- 
dermis more copious and of a softer texture. The valves 
which are opaque, strong, equal, and subrhomboidal in 
contour, are ordinarily ventricose in the adult, with their 
convexity tolerably evenly diffused, and become more or less 
flattened, but not concave, beyond the obtuse umbonal 
ridge. The entire surface, which beneath the pale or yel- 
lowish brown and somewhat squamose epidermis, is of a 
dull squalid white or light buff colour (dead valves are 
snow-white) is closely radiated with most numerous raised 
subgranulated strie, which are slightly stronger at both 
extremities, and decidedly more distant behind. Their in- 
terstices are either narrower or scarcely broader than these 
costellar striz, and are devoid of any radiating transverse 
striule, but occasionally reticulated from the lateral pro- 
jection of the granules. The anterior side, although de- 
cidedly the longer, is not very greatly so, its extremity is 
rounded below, and a little angular above; the hinder 
termination is more or less biangulated. The dorsal and 
ventral edges are nearly parallel ; the latter rises rather 
the more in front of the shell. The cardinal area is much 
sunken, not variegated, rather narrow, and of no great ex- 
tent ; the ligament itself is oblong-lanceolate, dusky, and 
marked throughout with most delicate striule, which run 
parallel to each other between the scarcely inclined and not 


240 ARCADZ. 


very distant beaks. The umbones are prominent. The 
interior is of an uniform white, and its margin is quite free 
from crenation; the hinge-margin increases greatly in 
breadth at both ends, its lower edge is incurved, and the 
teeth, which are rather numerous, enlarge considerably and 
nearly equally at both ends. 

Our largest specimen only measures three-quarters of an 
inch in length and half an inch in breadth. 

The animal, according to Mr. Clark, is oblong, thick, 
body white, mantle pale red towards the apex, entirely 
open, having the under surface of the ventral range marked 
on a very pale yellow ground with irregular fleshy blotches, 
and on the upper for some little depth with a sand-like 
rusty brown margin, and a darker interrupted bordering 
line near the slightly dentated edge. There are no equi- 
distant black points or ocelli as in Arca tetragona. The 
foot is white with a deep fissure at its bend, and is usually 
provided with a green byssal membrane by which it is 
attached to various substances, from which, however, the 
animal can freely cast itself off and spin a new byssus. 
Even when fixed the foot can be protruded for a consider- 
able length, and it then appears fleshy and tapering, and of 
a pure white colour. On each side of the body are two 
very thin narrow symmetrical pale brown branchiz, gradu- 
ally tapering on each side, uniting around the mouth, and 
forming, instead of palpi, a double lamina or lip. 

This little Ark is, in the main, a southern species. It 
occurs at Herm and elsewhere in the Channel Islands, 
profusely attached to dead bivalves (S. H.); Port- 
land Island in fifteen fathoms, occupying the crevices of 
shells, Penzance in twenty fathoms (M‘Andrew and 
BK. F.); Shelborne, Sandwich, Whitesand Bay, Ilfracombe, 


Fishguard in twenty fathoms, and Manorbeer, in Pem- 


ARCA. 241 


brokeshire (Jeffreys), Exmouth (Clark and Jeffreys), 
Tenby and Milford Haven (Lyons), Lundy Island in 
seven to twenty-seven fathoms (M‘Andrew), off the 
Norfolk coast (Captain Owen Stanley), Filey in Yorkshire 
(Strickland), Berwick Bay (Dr. Johnston), Ireland (Mr. 
Dillwyn), Bantry Bay (Mrs. Puxley). 

It is common in seas to the south of Britain, and abun- 
dant in the Mediterranean. 


A. RARIDENTATA, Searles Wood. 


Very small, white; posterior end greatly the broader: hinge 
with only three or four teeth on either side of the beak. 


Plate XLV. fig. 8. 


Arca raridentata, SEARLES Woop, Charlesworth’s Magaz. Nat. Hist. vol. iv. 
(1840), p. 232, pl. 13, £ 4 (fossil). — THomrson, Annals 
Nat. Hist. vol. xviil. p. 385. 
Arca Pectunouloides, “ Scaccut, Notizie, etc. p. 25, no. 62, pl. 1, f. 12,” 
(Philippi). — Jerrreys, Ann. Nat. Hist. vol. xix, p. 
313. — Purirrt, Moll. Sicil. vol. ii. p. 44, pl. 15, f. 8. 
—Lovin, Index Moll. Scandinay. (from specimens.) 


The general aspect of this elegant little Arca is rather 
peculiar, inasmuch as the radiating ribs, so universal in 
the recent species of this genus, are either almost absent 
or barely indicated ; and the shape, which is nearly semi- 
circular, but of great disparity in breadth at the two ex- 
tremities, is far from an ordinary one. ‘The valves, which 
are tolerably strong, almost opaque, and very nearly equal 
to each other in size and depth, are swollen at the umbones, 
from whence they diminish in convexity in nearly equal 
ratio on either side. They are of an uniform whitish hue, 
both within and without, and are decussated by fine close- 
set lamellar concentric strive, and still more delicate radiat- 
ing striule, the former being chiefly evident at the umbones, 


VOL. Il. EE 


242 ARCADA. 


the latter at the sides, and towards the lower margin of the 
shell. The straight dorsal margin is very nearly equal in 
length to the ventral, which latter is greatly arcuated, and 
ascends so remarkably, yet in a convex line, in front of the 
shell, as to excise, as it were, the lower anterior corner, and 
more or less sharply angulate the upper one. The posterior 
termination is broad, well rounded below, and above forms 
a more or less distinct obtuse angle; the hinder edge, and 
particularly its lower portion, curves outwards. The 
umbones are prominent; the beaks, which are small, 
and not much inclined, are approximate, the cardinal 
area being extremely narrow. There is no angulation 
of the umbonal ridge, nor any concave area behind it. 
The interior is of an uniform white; the hinge teeth, of 
which none exist in the middle part of the margin, only 
number three or four in front, and three behind: the latter 
are peculiarly oblique, the former decidedly large for the 
size of the shell. The internal margin is not distinctly 
crenated, but some obscure crenz occasionally appear at 
the narrower extremity. From the minute size of the 
species, the epidermidal covering is not very distinct; it 
seems, however, of a brownish ash-colour, and not pilous, 
but membranaceous. Our largest specimen only measures 
about two. lines at the broadest part, and is rather more 
than the fifth of an inch in length. 

The animal is of a white colour: otherwise unknown. 

The Arca raridentata was first discovered in a living 
state by Mr. M‘Andrew, who dredged it in the Minch fifty 
miles from the Shiant Isles, among the Hebrides, in fifty 
fathoms on a bottom of sandy gravel, and afterwards twenty 
miles off the west of Zetland in sixty fathoms, and near Foula 
in forty-five. Mr. Jeffreys has taken it in forty fathoms 
off Skye, and Mr. Barlee in the outer Hebrides. Far 


ARCA. 243 


apart from these localities for this rare shell is Cape Clear, 
the southern extremity of Ireland, off which it has been 
dredged by Mr. M‘Andrew in sixty fathoms. 

Abroad it occurs on the Norwegian coast from Bergen 
to Denmark, and in the Aigean in as deep as two hundred 
fathoms water. It is found as a fossil in the crag of 
England and newer Pleiocene of Sicily. 


A. BarBata, Linneus. 


Klongated oblong, brown ; ligamental area long and narrow. 


Arca barbata, Linn. Syst. Nat. (not Fauna Suec.) ed. 12, p. 1140. — Brown, 
Mem. Werner. Soc. vol. ii. pt. 2, p. 512. — Fiemine, Brit. 
Anim, p, 398.— Brit. Marine Conch. p. 102. — Brown, IIl. 
Conch. G. B. p. 86, pl. 33, f. 7. — Born, Mus. Ces. Vind. p. 
88. — Cuemn. Conch. Cab. vol. vii. p. 187, pl. 54, f. 535. — 
Pott, Test. Siciliz, vol. ii. p. 135, pl. 25, f. 6, 7. — Ditiw. 
Recent Shells, vol. i. p. 229.—Lam. Anim. s. Vert. (ed. Desh.) 
vol. vi. p. 465.— BiainviLLE, Manuel Malacol. pl. 65, f. 1.— 
Puiviert, Moll. Sicil. vol. i. p, 57, and vol. ii. p. 42. — HANt. 
Recent Shells, vol. i. p. 193, pl. 9, Arca, f. 3.—Rxxve, Conch. 
Icon. Arca, pl. 13, f. 88. — DEsHAvEs, Exp. Scient. d’Algérie, 
Moll. pl. 119 (anatomy). 

», reticulata, TuRTON, Conch. Diction. p. 7; Dithyra Brit. p. 168, 259. 


Elongated oblong, compressed cylindraceous, moderately 
solid, opaque, equivalve, very inequilateral, surface not 
shining, superficially brownish red, beneath which the tex- 
ture is white, reticulately scabrous (like a file), owing to 
the intersection of most closely disposed nearly equidistant 
depressed radiating costelle, and crowded but rather ob- 
scure concentric sulci. Coarse and somewhat flattened 
bristles of a dark umber-brown more or less profusely clothe 
the two extremities, and are arranged (the larger or prin- 
cipal ones) upon the middle portion of the shell in rather 
distant radiating series. Ventral margin straightish, or 


244 ARCADE. 


but little convex, subparallel to the dorsal edge, which is 
straight or slightly subincurved, and horizontal, or barely 
rising ; anterior side (in this example) more than twice the 
length of the other; its extremity a little narrowed, well 
rounded below, obscurely angulated above. Hinder ter- 
mination chiefly projecting below the middle; the oblique 
convex posterior edge forming an obscure obtuse angle with 
the dorsal margin; the lower corner somewhat rounded 
off. Umbones but little prominent and not far apart. 
Ligamental area long and narrow. Inside white ; margin 
indented a little by the external costelle: hinge-margin 
rather narrow, teeth numerous (about thirty-two). 

The animal is of a pale yellow colour. 

A single small specimen of this common Mediterranean 
shell, which measured fourteen lines in length, and not 
quite seven in breadth, is said to have been found alive, 
attached to an oyster at Kaillinchy in Lough Strangford, 
County of Down, Ireland, by Dr. Macgee, of Belfast. 
From this example (still preserved in the cabinet of Mr. 
Jeffreys), which is precisely identical with those of the 
Adriatic and Mediterranean, we have drawn up the above 
description. We have not ventured at present to include 
this shell positively among our indigenous productions, as 
no second example of a species usually abundant when 
present at all, has confirmed by its discovery the indigen- 
ousness of the recorded one; nor can we help surmising that 
there must have been some mistake made about it, for 
neither the habitat nor locality agree with the ordinary 
position and range of the species. 


PECTUNCULUS. Lamarck. 


Shell equivalve, equilateral or nearly so, orbicular, closed, 
smooth or striated or with radiating furrows, invested with 
a fimbriated epidermis; margins plain or crenate; beaks 
separated by a grooved lanceolate ligamental area ; liga- 


PECTUNCULUS. 245 


ment external; hinge semicircular, teeth oblique, small, 
interlocking. Pallial impression entire, muscular scars 
very strongly marked. 

Animal orbicular, its mantle freely open with simple 
margins which are somewhat enlarged in the branchial and 
anal regions ; foot large, semilunar, deeply grooved so as 
to form a disk with undulated edges; no byssus; lips 
formed of a linear prolongation of the branchial lamine. 


P. eiycimeris, Linneus. 


Plate XLVI. fig. 4, 5, 6, 7, and (Animal) plate P. f. 6. 


Listrr, Hist. Conch. pl. 247, f. 82.— Knorr, Délices des Yeux, 
pt. 6, pl. 14, f. 4. 
Arca glycimeris, LINN. Syst. Nat, ed. 12, p. 1143; Mus. Ulric. p. 521.— PEn- 
NANT, Brit. Zool. ed. 4, vol. iy. p. 98, pl. 58, f. 58.—Donoy. 
Brit. Shells, vol, ii. pl. 37, f. 2.— Maron and Rack. Linn. 
Trans. vol. vill. p. 93, pl. 3, f. 3. —Turr. Conch. Diction. 
p- 7-—Ditiw. Recent Shells, vol. i. p. 241.— Index Testa- 
ceolog. pl. 10, Arca, f. 36.—Mawe, Conchology, pl. 13, f. 7. 
Arca pilosa, LINN. Syst. Nat. ed. 12, p. 1143.— Putrznry, Hutchins’ Hist. 
Dorset. p. 35. — Mont. Test. Brit. p. 137, and Suppl. p. 53. — 
Maron and Racks. Jinn. Trans. vol. viii. p. 93, pl. 3, f. 4. — 
Dorset Catalog. p. 36, pl. 11, f. 2.—Turv. Conch. Diction. p. 6. 
— Ditiw. Recent Shells, vol. i. p. 242. — Index Testaceolog. 
pl. 10, Arca, f. 37. 
Glycimeris orbicularis, DA Costa, Brit. Conch. p. 168, pl. 11, f. 2. 
Arca undata, CHEMN. (not Linn.) Conch. Cab. vol. vii. p. 224, pl. 57, f. 560. 
55 marmorata, CHEMN. Conch. Cab. vol. vii. p. 228, pl. 57, f. 563 (probably). 
Pectunculus glycimeris, TuRToN (not Lamarck nor Philippi), Dithyra Brit. p. 171, 
pl. 12, f. 1.— Maceriuiv. Moll. Aberd. p. 238. — Brit. 
Marine Conch. p. 103.— Brown, LIllust. Conch. G. B. 
p. 85, pl. 33, f. 8, 9. — Burrows, Elements of Conch, 
pl. 8, f. 7. —Croucu, Introd. Conch. pl. 8, f 11.— 
REEVE, Conch. Iconica, Pectune. pl. 3, f. 12. 
“ pilosus, LaMARCK, Anim. s. Vert. (ed. Desh.) vol. vi. p. 448. — 
Turt. Dithyra Brit. p. 172, pl. 12, f. 2.—Frem. Encyel. 
Edin. vol. vii. p. 97, pl. 203, f. 18; Brit. Anim. p. 400.— 
Fores, Malacol. Monensis, p. 42.—Brown, Ill. Conch. 
G. B. p. 85, pl. 33, f. 10, 11.— Buarmyv. Manuel Mala- 
colog. pl. 65 bis, f. 83.—Puivippt, Moll. Sicil. vol. i. p. 61, 


246 ARCADE. 


and vol. ii, p. 44.—SowxErpy, Concholog. Manual, f. 134. 
— Hant. Recent Shells, vol. i. p. 162, pl. 10, Arca, 
f. 36, 37. 

Arca minima, Turt. Conch. Diction. p. 8. 

Pectunculus undatus, Turv. Dithyra Brit. p. 173, pl. 12, f. 3, 4. 


5 decussatus, Turt. Dithyra Brit. p. 173, pl. 12, f. 5. — FLEMING, 
Brit. Anim. p. 400.—Brit. Marine Conch. p. 104. 
” nummarius, TuRT. Dithyra Brit. p. 174, pl. 12, f. 6. — FLEMING, 
Brit. Anim. p. 400.—Brit. Marine Conch. p. 104. 
& variabilis (fossil), SowERByY, Min. Conch. t. 471, f. 1. 


Encyclopédie Méthodique, Vers, pl. 310, f. 3. 


Retaining in preference the name glycimeris, an epithet 
bestowed upon this shell even prior to the days of Linnzeus, 
in whose “Systema” it appeared in the tenth edition, 
pilosus being first annexed in the twelfth, we have regarded 
the two shells as forming but one species, inasmuch as 
those features upon whose existence their separation has 
been based, to wit, the obliquity of contour and greater 
inequality of the sides in the former, its angularity on the 
more produced side, and the radiating instead of concentric 
style of painting, are not constantly and collectively united 
in each individual, but so commingled in different exam- 
ples that the exact line of demarcation cannot possibly 
be determined. Nevertheless, a sufficient preponderance 
of the differential characters is usually present in each 
shell, to enable us to divide the species into two well- 
marked and easily distinguishable varieties. 

Both these have the ordinary orbicular form of the 
Pectunculi, the breadth of the valves being more frequently 
(not invariably) superior in the former variety, their length 
in the latter. In convexity both vary from scarcely ven- 
tricose to actually tumid, the profundity being chiefly um- 
bonal, and rather rapidly diminishing at the sides and base. 
The structure is solid, opaque, and often ponderous ; the 
exterior is never lustrous, but either dull or but slightly 


PECTUNCULUS. PAG 


glossy. In the variety pilosus the sides are generally 
equal, and the outline only exceptionally oblique: in the 
more ancient form, the opposite conditions more frequently 
prevail. In both the ground-colour is whitish or pale red, 
(in the fry the entire surface, except the colourless beaks 
and a few small scattered splotches of white, is occasionally 
rufous,) adorned with more or less broad zigzag markings 
of dirty red, arranged in the more typical specimens of 
glycimeris in a large and somewhat radiating pattern, but 
having a greater tendency in pi/osus to cluster together in 
numerous concentric fillets. The diversity of painting in 
the younger shells is infinite; one of the most beautiful 
of these is the nummarius of Turton (not of Linneus, 
whose type was a young violascens) which is exquisitely 
studded all over with minute red dots. Another pretty 
variation of colouring is where the ground is mottled with 
white and flesh-colour, and sprinkled with unconnected 
angular red markings upon the more sparingly distributed 
patches of the former hue. A white variety has been 
found at the Arran Isles on the Irish coast by Mr. 
Barlee. A decussation of most delicate radiating and 
concentric striule pervades the exterior, the concentric 
being the more manifest where the length of the shell 
exceeds the breadth, the radiating where it is inferior to it. 
This sculpture is far more prominent in the younger indi- 
viduals (P. decussatus of 'Turton), and becomes compara- 
tively obscure in some of the more aged ones; in addition 
there may be seen in certain examples of the variety 
pilosus a faint appearance (as in Siculus) of obsolete ribs, 
as though coste had once existed, and been abraded to 
the level of the general surface. 

The ventral edge is arcuated, and rises nearly equally 
on both sides, although much more rectilinearly so on that 


248 ARCADA. 


one to which the beaks incline. The extremity of this, 
although nearly equally broad with the other, is more or 
less subangulated at, or a little above, the middle; the 
opposite end is broadly rounded, the declination, how- 
ever, not vying with the basal ascent. The projecting 
umbones (which are occasionally oblique) are central, or 
nearly so; the ligamental area is moderately long, and 
rather narrow. ‘The interior is either white or brownish 
chocolate colour; if the former, then, for the most part, 
with more or less extensive stains of the darker hue upon 
the subangulated side; if the latter, with the muscular 
impression upon the rounded side almost always free from 
colouring matter. The former painting prevails chiefly in 
glycimeris, where the central portion of the hinge-margin 
is narrow ; the latter in pilosus, where that part is generally 
dilated at the expense of the ligament. 

The number of teeth is very variable, extending at fewest 
from six to twelve on each side; as a general rule they are 
least numerous in those shells with a white interior, and 
are always more plentiful on the subangulated side. A 
kind of velvety epidermis, of a yellowish-brown colour, 
varying much as to closeness or looseness of texture, 
clothes, for the most part, the exterior of the valves in the 
vicinity of the margin. 

Two inches may be regarded as the full diameter of the 
ordinary run of British examples; occasionally shells are 
taken of half an inch more in measurement, but the mass 
of individuals are ordinarily half an inch less than what 
we have stated. Our native specimens of the variety 
pilosus are inferior to the other in size; exotic ones, on 
the contrary, surpass it in that particular. 

The animal is shaped like the shell; its mantle is freely 
open, except in the region of the hinge; the margins are 


PECTUNCULUS. 249 


plain, of a yellowish grey colour, thickly dotted with 
minute dark purple specks, but plain yellowish internally. 
Mr. Clark has observed that at “the posterior side for 
half its length at the very verge of the mantle, are about 
twenty five most minute equidistant black points, besides 
two short brown transverse bars.” The margins of the 
mantle are produced into slightly expanded lips in the 
branchial and anal regions, and then tinged internally with 
purple, but they do not form siphons; though we have 
seen them assume the appearance of sessile orifices, owing 
to the habit the animal has of approximating their edges. 
‘“‘ Under and between the termination of the posterior ends 
of the branchiz is a very short cylindrical anal process, 
with a minute round reflexed margin” (Clark). The foot 
varies in colour from pure white to orange yellow; it is 
semilunar in shape, thick and deeply grooved; the margins 
of the groove are furbelowed ; the posterior extremity of 
the foot is often dotted with purplish brown. The branchize 
vary in colour from white to brownish yellow ; their fila- 
ments are free; each leaflet of each pair is equal, and of a 
suboval form. ‘‘ From their anterior termination a pair 
of light brown, long linear palps, smooth on both sides, 
originate and pursue their course around the mouth and 
meet the fellow pair on the other side.” 

This fine shell is so very generally distributed around our 
coasts, that to enumerate localities would be superfluous. It 
is absent from none of the districts, though more abundant 
in some places than in others. It is generally gregarious, 
preferring a nullipore bottom in from fifteen to twenty-five 
fathoms, but ranging from eight to as deep as sixty fathoms. 
It is generally distributed through the European seas, and 
as a fossil occurs frequently in the mammaliferous crag and 
northern drift. 


VOL. II. K K 


250 


AVICULACE. 


In this family, of which the British examples are few 
and rare, we have a passage from the dimyarian to the 
monomyarian lamellibranchiate bivalves, great groups, 
which though convenient sections, can scarcely be re- 
garded as of ordinal value. Avicula has usually been 
included in the latter, Pinna in the former section, yet 
not only are their animals very similar, but also their 
shells; for though Pinna appears of a very different 
shape from Avicula when placed with its truncated ex- 
tremity towards us, and its pointed beaks from us, 
yet that is not its natural position for comparison, since 
it is really an extremely oblique shell, and therefore 
should be placed before us in the direction of greatest 
dimension. The close affinity of these shells is further 
proved by their microscopic structure, as made known 
by Dr. Carpenter, who first maintained their relationship, 
associating in the same family the genera Perna, Malleus, 
Crenatula, Vulsella, Gervillia, and Inoceramus. All these 
genera have the exterior of the shells composed ‘ of 
prismatic cellular substance, and the interior of true 
nacre.” The size of the cells varies greatly in the dif- 
ferent groups. 

The animals of all the Aviculacee have freely open 
mantles, and a small foot with a powerful byssiferous 
gland. 


AVICULA. 251 


AVICULA. Lamarck. 


Shell oblique, inequivalve, inequilateral, upper valve 
most convex, lower one notched for the passage of the 
byssus; surface smooth, or scaly, or radiatingly ribbed ; 
hinge-line straight, often winged; a single cardinal tooth 
in each valve; ligament partially external, linear. Pallial 
impression entire; muscular scars two or more, one very 
large, the rest small. 

Animal shaped like the shell, its mantle freely open, 
with cirrhated margins; no siphons; foot small, cylindric, 
furnished with a byssal groove; palps large; adductor 
muscles very unequal, one being greatly larger than the 
rest. 

Although during ancient epochs sufficiently plentiful in 
the seas of our area, now we have but one species of 
this genus, and that one exceedingly rare. Its living 
allies are for the most part tropical, and some of them 
grow to a great size, and are remarkable for beauty 
or eccentricity of shape, or for the pearls they furnish; 
for Meleagrina, from species of which the best pearls are 
fished in the Indian Seas, is at best but a subgenus of 


Avicula. 


A. Tarentina, Lamarck. 


Plate XLII. fig. 1, 2, 3, and (Animal) plate S. fig. 4. 


Mytilus hirundo, Linn. Syst. Nat. ed. 12, p. 1159 (partly).—Turr. Conch. Dic- 
tion. p. 109, f. 7.— Pout, Test. Sicil. vol. ii. p. 221, pl. 32, f. 
17 to 21.—Dittw. Recent Shells, vol. i. p. 321 (var. G.).— 
Maweg, Introd. Linn. Conch. pl. 16, f. 6—Cosra, Cat. Test. 
Sicil. p. 59. 
» € mari Mediterraneo, CHEMN. Conch. Cab. vol. viii. p. 142, pl. 81, f. 725. 
Avicula hirundo, Turr. Dithyra Brit. p. 220, pl. 16, f. 3,4.—FLem. Brit. Anim. 
p- 405.—Brit. Mar. Conch. p. 113. 


252 AVICULACES. 


Avicula Tarentina, Lam. Anim. s. Vert. (ed. Desh.) vol. viie p. 99.—Brit. Mar. 

Conch, f. 109.—Desu. Encyclopéd. Méthod. Vers. vol. ii. 
p- 99.—Puinippi, Moll. Sicil. vol. i. p. 76, and vol. ii- p. 
55.—Hant. Recent Shells, vol. i. p. 262.—DeEsH. Exp. 
Scient. Algérie, Moll. pl. 129. 

»» falcata, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 98 (fide Desh.) 

5, aculeata, SowERsy, Genera Shells, Avicula (from Madeira), f. 2 (proba- 
bly).—ReEEvE, Conch. Systemat. pl. 109, f. 2 (from last). 

»  Anglica, Brown, Illust. Conch. G. B. p. 74, pl. 23, f. 3. 

5, Allantica, Brown, Ill. Conch. G. B. p. 74, pl. 46, f. 7 (from Turton’s 

figure). 
Encyclopédie Méthodique, Vers, pl. 177, f. 8. 


It is difficult to find any object to which we may liken 
the shape of this graceful bivalve; some individuals, how- 
ever, whose wing is peculiarly elongated, have a contour 
like that of a falchion. Perhaps the image of a mussel 
placed in an oblique position, with a small subtriangular 
lobe on one side of its apex and an elongated wing- 
shaped appendage on the other, would convey as near 
an ideal of its shape, as can be approached by lan- 
guage. The shell is thin and extremely fragile, mode- 
rately convex, and with more or less of a resinous gloss. 
The colour is of a pale olivaceous yellow, with more or 
less distinct and numerous rays or blotches of a smoky 
brown; sometimes there are clusters of zigzag streaks, 
or even long and uninterrupted rectilinear ones, but their 
arrangement is invariably radiating. The surface which 
is usually smooth upon the umbones, is elsewhere either 
marked with somewhat remote concentric strize, or covered 
towards the margin with rather distant foliaceous subim- 
bricated lamine. These, in the finer examples, are closely 
set with appressed and somewhat spinous scales, which, 
however, are almost invariably abraded in the old, and 
not yet developed in the young, exhibiting only more 
or less faint indications of a foliaceous structure. The 


AVICULA. 253 


body or main portion of the shell is (in the more typical 
examples) very oblique and rather narrow; the ventral 
outline is strongly arcuated, forming one wide sweep from 
the end of the lobe to the most produced extremity of 
the body, which latter is decidedly but not immoderately, 
shorter than the subtriangular wing, the sinus beneath 
which is not particularly profound, and more frequently is 
inferior to, than it exceeds, a right angle, but varies much 
in depth and extent, according to the greater or lesser 
elongation of the dorsal wing. Generally speaking, a 
straight line drawn from the beaks to the most project- 
ing part of the lower margin is equal or nearly so to 
the extreme length of the wing edge. The trigonal lobe 
is moderately large, and in the more convex valve as 
broad as it is long; the byssal passage prevents this 
being the case in the lesser valve. The beaks are pro- 
minent, and not usually adjacent to each other. The 
lobes and the area between the body and the wing are 
much compressed, and the dorsal or cardinal line is very 
long. The sides of it are extremely unequal, the upper 
edge of the wing being from four to six times the length 
of the upper edge of the lobe; the greater dispropor- 
tion more usually exists in the adult. There is a single 
small blunt somewhat triangular tooth under the acute, 
very oblique but inflected beak in one valve, and two 
obsolete denticles in the other. The medial portion 
only of the interior is covered with a thin stratum of 
nacre, which is usually prismatic. 

The largest individual we have observed measures nearly 
four inches in length. 

The little specimen (a single valve) delineated by Tur- 
ton in both his “ Dictionary” and “ Dithyra,” can only, 
we imagine, be regarded as a variety of this shell, although 


254 AVICULACEA. 


its outline seems very different. Its body (partly, how- 
ever, from the terminal edge being chipped) seems less 
narrow, oblique, and produced than usual; the surface 
is worn smooth, and the preponderance of darker markings 
causes it to appear rayed with yellowish white on a ground 
of chocolate brown. 

The animal, which we have seen alive in the Mediter- 
ranean, is of a yellowish white colour. Its mantle edges 
are freely open; each pendant margin is fringed with a 
basal range of short closely-set white cirrhi and a mar- 
ginal row of rather long ones, which, as well as the mantle 
itself, are whitish, mottled with brown. The branchiz are 
white. The foot is white, short and small in proportion to 
the animal, and spins a strong byssus from its basal groove. 

This is a very rare shell, as a British species, and has 
hitherto been found only towards the South. It was first 
taken by Miss Hutchins in Bantry Bay, and Mr. Warren 
has two specimens from the neighbourhood of Dublin. On 
the English coast it has occurred in Devon and Cornwall. 
It is more frequent in the Mediterranean Sea.* 


PINNA, Linnzus. 


Shell very oblique, wedge-shaped, triangular, equivalve, 
exceedingly imequilateral, more or less thin and _ fragile, 
gaping posteriorly ; surface smooth, or scaly, or obliquely 
furrowed ; beaks terminal. Hinge straight, long, tooth- 


* Turton, in his ‘‘ Conchological Dictionary of the British Islands,” has intro- 
duced (p. 108) the Avicula Morio of Leach (Zoological Miscellany, pl. 38, f. 2), 
but has virtually withdrawn it by omitting the species in his subsequent quarto 
on British Bivalyes. It is very probable that the specimen stated to haye been 
dredged by Mr. Prideaux in Plymouth Sound was only our ordinary British 
species ; at least nothing in the very brief description militates against the suppo- 


sition. 


PINNA. 255 


less ; ligament linear, internal. Pallial impression entire, 
muscular scars very unequal. 

Animal triangular, mantle freely open, no siphons ; 
mantle-margins with cirrhated edges; mouth with foli- 
aceous lips and short palps; anus furnished with a long 
lingulate valve ; foot small, with a byssal groove ; adductor 
muscles very unequal. 

This genus is an ancient one; species of it presenting 
marked resemblance to existing forms are present in oolitic 
strata. The number of living species is not great, but they 
are widely distributed, and many of them remarkable for 
their size. Our native Pinna is the largest bivalve in- 
habiting the British seas. The Pinne are mostly sub- 
littoral, but are capable of considerable ranges in depth. 
They live in sand and mud, their gaping extremity up- 
wards and their beaks plunged deep in the ground. Their 
byssus is strong and silky, and in Sicily is sometimes made 
into gloves or stockings, more for curiosity than use. A 
little crab is often found within the shell when the true 
inhabitant is alive, and many fables have been narrated of 


their friendship. 


P. pectinata, Linneus. 


Plate XLITI. fig. 1, 2, and Plate LIII. fig. 8. 


Pinna pectinata, Linn. Syst. Nat. ed. 12, p. 1160.—PuttEney, Hutchins, Hist. 
Dorset, p. 39.—Monv. Test. Brit. p. 178.—Maron and 
Rack, Trans. Linn. Soc. p. 113.—Racxerrt, Dorset Catalog. 
p- 41, pl. 3, f. 3.—Turr. Conch. Diction. p. 148, f. 11; Dithyra 
Brit. p. 223, pl. 19, f. 1.—FLemine, Brit. Animals, p. 406. 
—Lam. Anim. s. Vert. (ed. Desh.) yol. vii. p. 64 (partly).— 
Ditiw. Recent Shells, vol. i. p. 325.—Mawe, Linn. Conchol., 
pl. 17, f. 1.—Hant. Recent Shells, vol. i. p. 253. 
» fragilis, PENN, Brit. Zool. ed. 4, vol. iv. p. 14, pl. 69, f. 80.—Turr. 
Dithyra Brit, p. 222, pl. 20, f. 2,—FrLemine, Brit. Anim. p. 


256 AVICULACES. 


406.—Brit. Marine Conch. p. 111.—Brown, Illust. Conch. 
GOB Spsospl2ostarde 
Pinna muricata, Da Costa (not of authors) British Conchol.’p. 240, pl. 16, f. 3.— 


Donov. Brit. Shells, vol. i. pl. 10.—Crovucn, Introd. Lam. 
Conch. pl. 11, f. 4. 

»»  *gens, Monv. Test. Brit. p. 180, 583, and Suppl. p. 72.—MarTon and 
Rack, Trans. Linn. Soc. vol. viii. p. 113.—Turv. Conch, Dic- 
tion. p. 148; Dithyra Brit. p. 222, pl. 20, f. 1—FLEM1Ne. 
Encyclop. Edin. vol. vii. pl. 206, f.3; Brit. Anim. p. 406.— 
Coucu, Cornish Fauna, pt. 2, p. 34.—Maceiitiv. Moll. Aberd. 
p- 240.—Brit. Marine Conch. p. 111.—Browy, Illust. Conch. 
G. B. p. 75, pl. 26, f. 1.—Diniw. Recent Shells, vol. i. p. 325. 
—Lam. Anim. s.- Vert. (ed. Desh.) vol. vii. p. 66.—Index 
Testaceolog. pl. 12, Pinna, f. 3.—Hanu. Recent Shells, vol. i. 
p: 253, pl. 12) £. 3. 

» levis, Donoy. Brit. Shells, vol. y. pl. 152. 

»  papyracea, TurT. Dithyra Brit. p. 224, pl. 20, f. 3—Friemine, Brit., 

Anim. p. 407.—Brit. Marine Conch. p. 112, 

»  rotundata, Coucu, Cornish Fauna, pt. 2, p. 36. 

» elegans, Brown, Illust. Conch. G. B. p. 76, pl. 26, f. 2. 


The members of this genus, which, from the usual 
abrasion of their spinous sculpture with advancing age, are 
far more characteristic in their earlier state, become occa- 
sionally so altered in outline, when old, that several spe- 
cies have been constituted (as in the present shell, in the 
nobilis of the Mediterranean, &c.) from the different stages 
of increase. 

The valves, which are of a lighter or darker horn-colour, 
and neither rayed nor mottled with any other hue, except 
that near the umbones they are shaded with somewhat 
metallic tints of dirty green or smoky purple, are semi- 
transparent when young, moderately ventricose, and strongly 
hiant at the broader extremity. About a dozen slightly 
elevated rounded narrow ribs emanate from the beaks and 
radiate posteriorwards, but often in the young, and almost 
invariably in the adult, become obsolete before they reach 
the hinder extremity. These, however, do not occupy the 
entire surface of the shell, since the lower or ventral portion 


PINNA. ae 


(about a third or a fourth of the entire area) is not 
traversed by them. No echination is visible, for the most 
part, upon the more aged examples, but short upright 
caducous vaulted scales, of small size, and disposed at 
moderately distant intervals, often crown the ridges of the 
younger specimens; in which case there is generally a 
kind of obscure radiation of obsolete scales upon the portion 
otherwise devoid of sculpture. The concentric wrinkles of 
increase, although not forming (as in certain Pinne) a 
distinct lattice-work, are nevertheless rather prominent in 
the older shells, run nearly at right angles to the dorsal 
or hinge margin, and often give, by their convergence at 
the basal margin, a laminated appearance to the structure 
of the valves. The dorsal edge is not (as in certain allied 
species) incurved towards the beaks, but is nearly recti- 
linear in the more regularly developed individuals, with a 
descending inclination near the narrow end of the shell. 
The ventral edge, after the ordinary anterior indentation and 
subsequent swell, runs in young shells (that do not exceed 
six inches in length) almost subparallel to the upper margin 
and in nearly a straight line, so that (except in stunted 
individuals) the broad end of the valves is somewhat 
squared, and by no means peculiarly broad ; the terminal 
edge is, however, convex or even arcuated. With advanc- 
ing age, as the upper and lower margins diverge farther 
from each other, the general contour becomes more broadly 
triangular, the dorsal edge slopes a little downward at its 
termination, the ventral margin becomes more produced in 
proportion (in the young it is inferior in length to the 
opposite edge), and the terminal or posterior outline usually 
assumes a more rounded or arcuated appearance. The 
interior either partakes of the external colouring, or is dark 
and subnacreous. 


VOL. II. L L 


258 AVICULACEA. 


This species, as Montagu observes, is not uncommonly 
twelve inches long, and seven inches broad at the gaping 
end. Individuals, indeed, of still larger dimensions are ob- 
tained near Torquay, in S. Devon (S. H.). Montagu 
discovered a bed of these shells on a gravelly bottom 
covered with mud and long seaweeds at Saleomb bay, in the 
same county, which was only occasionally accessible when 
the tide receded beyond its usual limits. The valves stood 
upright with the broader end about an inch above the sur- 
face, and the lower end fixed so firmly to the soil by a very 
large strong byssus two or three inches in length, composed 
of numerous fine silky fibres of a dark purplish brown, 
as to demand the exercise of considerable force for their 
removal. ‘‘ Some of these shells have been taken annually 
for many years, the animal having been accounted very 
good food; but they require at least five or six hours 
stewing to render them eatable ; if this is properly attended 
to, they are nearly as good as Scallops, but never so 
tender” (Mont.). Weymouth and Dorset coast (S. H.). 
Off Eddystone Lighthouse (Montagu); Milford Haven 
(Lyons); Hebrides (Montagu); Zetlands in deep water 
(E.F.). Off Cape Clear in sixty fathoms dead (M‘Andrew). 
Rare on the west coast, except towards the south, where 
all the varieties have been observed ; coasts of London- 
derry, Antrim, and Down; in fifty fathoms off Island 
Magee on the Antrim coast (W. Thompson); Cove of 
Cork (Humphreys, Ball). It occurs on the other Euro- 
pean coasts.* 


* “ This species,” observes Couch, in his Fauna of Cornwall, “is found in the 
greatest abundance at the distance of from three to six leagues south of the Dead- 
man Point, where they stud the bottom in multitudes, with only two or three 
inches of the pointed end inserted into the soil. It is common for the line or hook 
to become entangled among these shells, and powerful effort is required to drag 
them from their attachment, which is only effected by breaking the byssus, or 


PINNA. 259 


SPURIOUS. 


P. carnea, Gmelin. 


Knorr, Délices des Yeux et de l’Esprit, pt. 2, pl. 23, f. 1. 
Pinna haud ignobilis, CoEMN. Conch. Cab. vol. viii. p. 212, pl. 87, f. 769. 
»»  saccata, SCHROTER (not Linn, nor authors), Einleit. Conch. vol. iii. pl. 9, 
£7. 
» carnea, GMELIN, Syst. Nat. p. 3865.—Dittw. Recent Shells, vol. i. p. 
326 (chiefly).— Index Testaceolog. pl. 12, Pinna, f. 6.— 
Han ey, Recent Shells, vol. i, p. 252, pl. 12, Pin. f. 6. 
»  muricata, PULTENEY (not author’s), Hutchins, Hist. Dorset, App. p. 39.— 
Monr. Test. Brit. p. 183, pl. 5, f. 3.—Dorset Catalog. p. 41. 
—Torr. Conch, Dict. p. 149 ; Dithyra Brit. p, 224.—FLEM- 
ING, Brit. Anim. p. 406. 
»  fiabellum, LAM. Anim, s. Vert. (ed. Desh.) vol. vii. p. 61 (in part). 


A West Indian shell, introduced by Pulteney as found on the 
Dorset coast, but repudiated as British by most subsequent writers. 
The original specimen, which is so worn as to be almost entirely 
destitute of scales, is much less obliquely rounded at the wider end 
than that represented by Montagu, and exhibits six or seven rather 
broad longitudinal coste. The P. muricata of the Linnean Trans- 
actions (vol. viii. p. 113) is different, being copied verbatim from 
the “ Museum Ulrice.” 


tearing away the ground to which it is attached. In the latter case, a rich harvest 
of shells is often afforded, but the pointed end of the Pinna is usually broken off 
by the violence. It is perhaps owing to the different degree in solidity of the 
ground, that the shells living in the deeper water are so much less buried than 
those of which Montagu speaks, and one of the consequences may be a greater 
degree of motion in the shell. Montagu observes that the exposed end cannot be 
closed by art, but the animal is capable of effecting it, and observation has taught 
me, that this is its method of obtaining food. In its ordinary position this open- 
ing is about two inches wide, exposing the contained animal which occupies but a 
smail portion of the cavity, and seems to offer itself as a prey to the first creature 
that may choose to devour it. Some fish is thus tempted to enter, but the first 
touch within is a signal for its destruction. The shell closes not only at the 
side but top, the latter action being effected by the separation of the pointed 
ends, and the captive is either crushed to death, or soon perishes, from con- 
finement.”” 


260 AVICULACEA. 


Perna avata, Gmelin. 


Knorr, Délices des Yeux, pt. vi. pl. 21, f. 1. 
Ala corvi pendula, CHEMN. Conch, Cab. vol. vii. p. 253, pl. 59, f. 581. 
Ostrea alata, GMELIN, Syst. Nat, p. 3339.—DiL.w. Recent Shells, vol. i. p. 283. 
» perna, Woop, Index Testaceolog. pl. 11, f. 78. 
Perna obliqua, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 75.—HANL. Recent 
Shells, vol. i. p. 258. 
3  ephippium, SowERBy (not Lam.) Genera Shells, Perna, f. 2.—REEVE, 
Conch. System. pl. 106, f. 2. 
Crenatula Travisit, Turt. Mag. Nat. vol. vii. p. 350, f. 47.—Brown, Lllust. 
Conch. G. B. p. 75, pl. 23, f. 20. 


A West Indian shell ; introduced by Turton as found at Scar- 
borough. The type, which exactly resembles the figure of the 
young shell attached to the adult Perna, in the Genera of Shells 
by Mr. Sowerby, was taken from the bottom of a foreign vessel. 


261 


OSTREAD. 


Tuts large and important family includes shells of very 
various outline and sculpture constructed by animals pre- 
senting considerable variations in the features of their 
foot and mantle, but nevertheless having so many impor- 
tant characters in common that we do not think it ad- 
visable to subdivide the group. For though the foot in 
Ostrea is obsolete the other characters of the animal of 
that genus are such that we cannot place it in a distinct 
group from Anomia on the one hand, or Placuna on the 
other, through both which genera we have a very natural 
transition into Pecten. The long fringes of the mantle in 
Lima might seem to indicate a different family, but in 
Lima spinosa we find them very short and associated with 
ocelli as in Pecten, and in Limea* the mantle has no 
tentacles. All the tribe have the mantle freely open, no 
tubes, a small or obsolete foot probably capable in some 
stage of the animal’s existence of spinning a byssus, and 
constantly doing so in some species, united adductor 
mussels, leaving a single impression in the shells, and a 
ligament wholly, or partly interior, lodged in a cardinal 
groove, and sometimes accompanied with teeth. 


* Among the future additions to the British Fauna will probably turn up 
Limea Sarsii of Loven, a shell which seems to be identical with the Lima crassa 
of the Egean. 


262 OSTREADZ. 


LIMA, Brucibre. 


Shell more or less obliquely oblong, equivalve, usually 
inequilateral, closed in front, more or less gaping at the 
sides, eared on each side of the hinge. Surface smooth, 
or striated and grooved in a radiating fashion, the ribs 
often scaly. Beaks separated by a rhomboidal area. Liga- 
ment occupying the expansion of the hinge-line on each 
side of a strong cartilage, set in a triangular pit under 
the beak of each valve. Pallial impression entire, muscular 
scar eccentric. 

Animal oval, mantle freely open, its margins pendant 
and fringed with long tentacular filaments. Ocelli absent 
or inconspicuous. No siphons. Body produced, in part 
linguiform. Foot small, ligulate, furnished with a byssal 
groove. Labial palps subtriangular, small, pectinated ; 
mouth surrounded by tentacular filaments; anal tube 
cylindric, externally visible. Branchial leaflets equal on 
each side. 

The species of this genus bear a close affinity to Pecten, 
yet constitute avery natural group of themselves. The 
Lime appeared in very ancient epochs, and during the 
oolitie period, species were comparatively abundant and 
attained great dimensions. The fossil genus Plagiostoma 
is synonymous with Lima. Some twenty well marked 
forms inhabit existing seas, living in various depths of 
water, either free or moored by a byssus or enveloped 
in nests formed of byssal filaments. 

The animals are very beautiful and curious, and often 
much larger than their shells, which in the greater number 
of species, though remarkable for elegance of outline and 


sculpture, rarely present any other colour than a milky 


LIMA. 263 


white. The majority of known living species come from 
the South Seas and Indian Ocean. 

A sub-genus Limatula has been proposed by Mr. 
Searles Wood for those species which are nearly equilat- 
eral. Neither their shells nor animals materially differ 
from their more oblique congeners. 


L. supauricutata, Montagu. 


Valves much swollen, nearly equilateral ; neither oblique nor 


gaping. 
Plate LITI. fig. 4, 5. 


Pecten subauriculatus, Mont. Test. Brit. Suppl. p. 63, pl. 29, f. 2.—FLEMING, 
Encyclop. Edin. pl. 205, f. 12. 
Ostrea subauriculata, Turt. Conch. Diction. p. 131.—Index Testaceolog. Suppl. 
pl. 2, Ostrea, f. 5. 
Lima subauriculata, Turt. Dithyra Brit. p.218.—FLEmine, Brit. Animals, p. 
388.—Brit. Marine Conch. p. 114.—Sowrrsy, Thesaur. 
Conch. vol. i. p. 84, pl. 22, f. 23.—Puuxieri, Moll. Sicil. 
vol. ii. p. 56.—Han ry, Recent Shells, vol. i. p. 266, 
suppl. pl. 2, Ostrea, f. 5.—Lovin, Index Moll. Skandinay. 
p. 32. 
» nivea, Puriirt, Moll. Sicil. vol. i. p. 78. 
» suleata, Brown, Mlust. Conch. G. B. p. 74, pl. 23, f.4, 5.—Mo.ir, Moll. 
Groenlandiz, p. 16. 
», sulculus, LovEN, Index Moll. Skandinay. p. 32? 
Limatula subauriculata, 8. V. Woon, Mag. Nat. Hist. new series (Charles- 
worth’s), vol. iii. p. 236, pl. 3, f. 6 (fossil). 


At present this species, which bears a remarkable like- 
ness to the dullata of Born, but differs as well by its 
size, as by the much greater tenuity and number of its 
costelle, which even in the earlier stages in that exotic 
shell are manifestly coarse, and comparatively few, is by 
far the rarest of our Lima, and, indeed, is one of our 
searcest bivalves. It is extremely tumid, almost equi- 
lateral, and scarcely at all oblique, excessively fragile 


264 OSTREADA. 


and subdiaphanous, white in the young, but rather stronger 
and more opaque in the larger single valves which are 
occasionally discovered. When viewed sideways, its 
united valves appear distinctly heart-shaped; the swell is 
chiefly manifest upon the middle portion of the shell below 
the umbones, and diminishes rapidly and nearly equally 
on either side of them. The valves which are closed on 
both sides, are divided in the middle by a concave ra- 
diating groove, on either side of which the surface is 
set with very fine and closely crenulated radiating cos- 
telle, which do not extend to the extremities of the 
shell, but for the most part occupy only the middle 
portion of it. The interstices, which are larger than the 
costelle, are not squarely cut out, but slightly shelving, 
which causes the latter to become more or less acute 
at their upper edges. The shape of the shell is nearly 
elliptical, and its sides are of nearly similar curvature, 
both arching almost uninterruptedly to the attenuated 
and well-rounded ventral margin; the greatest length of 
the valves is scarcely above the middle. The hinge- 
margin is nearly equal to one-third of the breadth, and 
scarcely declines in the least on either side of the pro- 
minent umbones, whose apices (the beaks) are rather 
distant, and directly inflected, not leaning to either side. 
The ligamental area is moderately wide, its central oval 
(in fresh specimens) is orange-yellow, the remaining por- 
tion is light green. The auricles are of equal size, and 
distinctly angulated, the angles being rather more than 
rectangles. 

The largest single valve in our cabinet measures slightly 
beyond seven lines in width, and rather exceeds one-third 
of an inch in length; although occasionally still larger 
valves are met with, the average of living examples can 


LIMA. 265 


scarcely be computed at more than five lines in breadth, 
and three in length. 

The animal closely resembles that of Lima bullata. 
The tentacula are of a pale pink colour, and the foot and 
body are of a pale orange hue. We have never observed 
it to make a nest. It lives for the most part on very 
muddy ground. 

This is a rare shell and very seldom taken alive. A 
single valve at Herm (S. H.). Pollkerar Cove (Miss Layers). 
Whitesand Bay (Jeffreys). Off Plymouth in twenty-five 
fathoms, and Penzance in twenty fathoms (M‘Andrew and 
E.F.). Off Laxey, Isle of Man, in fifteen fathoms (EH. F.). 
At Oban in fifteen fathoms, mud; off Cape Wrath in fifty 
fathoms, and at the same depth in the Minch, and between 
Fair Island and the Zetlands (M‘Andrew and E. F.). 
Lochs Alsh and Carron (Jeffreys). Eda Sound, Orkney, 
among coral and broken shells (Thomas). Loughs of 
Strangford and Belfast extremely rare (W. Thompson). 
It ranges along all the coasts of Europe. 


L. Loscomsn, Sowerby. 


Valves swollen, inequilateral, oblique, closed on one side, 
gaping slightly at the other. 


Plate LITI. fig. 1, 2, 3. 


Pecten fragilis, Mont. (not Chemnitz) Test. Brit. Suppl. p. 62. 
Ostrea fragilis, Turt. Conch. Diction. p. 131. 
Lima bullata, Turr. (not Ostrea bullata, Born) Dithyra Brit. p. 218, pl. 17, f. 
4, 5.—Brit. Marine Conch. p. 114. 
» Loscombii, SowERBy, Genera Shells, Lima, f. 4.— Macemurv. Moll. 
Aberd. p. 228.—RerxEve, Conch. Systemat. pl. 112, f. 4.— 
Sowrrsy, Thesaur. Conch. vol. i. p. 86, pl. 22, f. 20, 21, 
22.—Hant. Recent Shells, vol. i. p. 267. 
» Jragilis, Forpes, Magaz. Nat. Hist. vol. viii. p. 594, f. 65; Malac. 
Monens. p. 40.—Browy, Ill. Conch. G. B. p. 74, pl. 23, f. 6, 
7, 7*.—S. V. Woop, in Mag. Nat. Hist. new series (Charles- 
worth’s), vol. iii, p. 235, pl. 3, f. 3. 


VOL. Il. MM 


266 OSTREADA. 


This very delicate and fragile Lima is of an uniform 
pure and somewhat transparent white. Its valves, which 
are alike both in size and profundity, are obliquely sub- 
ovate, and more or less swollen. The convexity, which 
is chiefly manifest upon the umbonal region, diminishes 
thence with tolerable evenness on either side; but from 
the posterior lateral compression, the shell appears rather 
deeper at that extremity. The united valves when exa- 
mined sideways appear heart-shaped, owing to the distinct 
but gradually diminishing ventricoseness of the valves 
towards the base of the shell. 

The sculpture merely consists of fine radiating elevated 
strie (with, for the most part, still finer intervening 
ones), which are simple (not distinctly granular or squa- 
miferous), very numerous, chiefly perceptible and farthest 
apart near the centre, more crowded and gradually disap- 
pearing in front, and rather more abruptly obsolete pos- 
teriorly. The posterior margin runs in a nearly straight 
and almost uninterrupted line; the anterior edge first 
inclines forward in an arcuated line, then suddenly bend- 
ing back, runs in a convex line to the somewhat at- 
tenuated and well rounded ventral margin, so as to be 
subparallel (although rather more oblique) to the opposite 
edge. The chief anterior swell is decidedly above the 
middle, and most frequently, in the full-grown shell, 
at about two-fifths the distance from the hinge-margin. 
There is no posterior gape, and only a very slight linear 
hiation at the front dorsal region. The hinge-margin is 
very short, not much more than a quarter of the width 
of the shell, and declines with tolerable evenness on either 
side. The auricles are tolerably distinct and well de- 
fined; both form obtuse angles, but the lateral outline of 
the hinder is more concave than that of the other. The 


LIMA. 267 


ligamental area is of moderate breadth, and the beaks 
prominent and rather broad. 

Three-quarters of an inch in breadth, and half an inch 
in length, are the dimensions of rather large examples. 

Animal shaped like the shell; it is of a colour varying 
from pale orange to pale crimson, the mantle margins being 
reddish white ; they are quite open all round in front and 
at the sides, plain at their free edges and fringed with 
three rows of long tentacular filaments at their junction 
with the shell: the innermost series of these is longest. The 
body is white; the foot small, cylindrical, and furnished 
with a conspicuous byssal groove. 

The habits of this species have been observed by Mr. 
Clark, who has seen it “‘ repeatedly fix itself by fine byssal 
filaments, then detach itself and move with the greatest 
rapidity, crossing a dish of six inches’ diameter whilst one 
could be counted. The rounded extremity is that which 
is in front and the beaks behind, when the animal moves : 
this operation is performed by placing itself on the whole 
length of the straighter or ventral range, having the dorsal 
or rounded side uppermost ; then opening its valves wide, 
it suddenly flaps them together, and so on, and thus moves 
with extraordinary celerity ; not using the foot, which 
appears to this animal to serve rather for fixing itself than 
for motion.” 

This is the most generally distributed of our British 
Limas, though from the delicacy of its shell, it is difficult to 
obtain perfect specimens. Herm at low water (S. H.); 
Portland Island in fifteen fathoms, Penzance in twenty 
fathoms, Anglesey in ten to twenty-five fathoms, gravel 
(M‘Andrew and E. F.). Exmouth (Clark); Isle of Man 
in twelve to twenty-five fathoms, on Nullipore ground and 
Scallop banks (E. F.); rare at Scarborough (Bean); and 


268 OSTREADZ. 


on the Northumbrian coast (Alder). Oban, Loch Carron, 
Ullapool, and Lerwick (Jeffreys). Off Cape Wrath in 
fifty fathoms, the Zetlands in fifteen and fifty fathoms, 
Moray Firth in thirty-four fathoms (M‘Andrew); Eda 
Sound, Orkney, and off Aberdeen (Thomas). ‘ Hach side 
of the Irish coasts ; dredged sparingly in the deeper parts 
of the Loughs of Strangford and Belfast (Thompson).” It 
ranges throughout the European seas. 


L. n1ans, Gmelin. 
Valves shallow, gaping at both sides. 


Plate LII. fig. 3, 4, 5, and (Animal) plate R. (under the name of L. tenera). 


Die klaffende Kammuschel, (The gaping Pecten) ScHROTER, Hinleit. Conch. yol. 
iii. p. 332, pl. 9, f. 4. 
Ostrea hians, GMELIN (from Schroter), Syst. Nat. p. 3332.—Ditiw. Recent 
Shells, vol. i. p. 270.—Index Testaceol. pl. 11, f. 53. 
Lima tenera, Turt. (not Ostrea tenera of Chemn.) Zoolog. Journ. yol. ii. p. 362, 
pl. 13, f. 2,—Forsrs, Malac. Monens. p. 41.—Brown, Illust. 
Conch. G. B. p. 74, pl. 23, f. 8, 9.—Puiviprt, Moll. Sicil. vol. i. 
p- 77, and vol, ii. p. 57, pl. 16, f. 3. 
», Oullata, PAYRAUDEAU, Moll. Corse, p. 70.—D’OrsiGNy, Moll. Canar. p. 
101. 
» vitrina, Brown, Conchol. Text-Book (1833), p. 113, pl. 15, f. 7; Illust. 
Conch. G. B. p. 74, pl. 23, f. 10, 10*, 11, 11*. 
» fragilis, FLEMING, Brit. Animals, p. 388 (in part)—Coucu, Cornish 
Fauna, pt. 2, p. 37. 
Lime, Forses, Mag. Nat. Hist. vol. viii. p. 593, 594, fig. 63, 64. 
»  wmflata, ForsEs, Malacolog. Monensis, p. 41.—Brown, Ill. Conch. G. B. 
p. 74. 
» aperta, SowERBy, Thesaur. Conch. vol. i. p. 87, pl. 22, f. 26, 27, 28, 29. 
—Brit. Marine Conch. p. 249.—HANLEy, Recent Shells, yol. i. 
p- 268. 
» Sarsii, KRGyER (fide LovEN). 
» hians, LovEn, Index Moll. Skandinayia, p. 32. 
5 eailis, S. V. Woop, Mag. Nat. Hist. new series, vol. iii, (Charlesworth’s) 
p. 234, pl. 3, f. 1 ? (fossil). 
3, oblonga, S. V. Woon, Mag. Nat. Hist. new series, vol. iii, p. 234, pl. 3, 
f. 2 (fossil). 


The peculiar hiation of this widely-diffused species, which, 


LIMA. 269 


although the last described of our British Lime, was known 
to the student of general Conchology, long before the 
days of Montagu (who first introduced a member of this 
genus into the Fauna of Great Britain), readily enables us 
to discriminate specimens, however aberrant, from the two 
other species which inhabit our islands. The form is 
obliquely and unsymmetrically suboval, and more produced 
than in most species of its genus. It is much and rather 
suddenly attenuated above, narrowed and moderately 
arcuated below, and decidedly gaping at both extremities. 
The front hiation is extremely large, forms a narrow oval 
cavity as far as the bend of the anterior side, and then 
rather abruptly contracting, extends with very gradual di- 
minution even to the ventral margin. The hinder gape is 
much narrower, and in the young shell, where it is almost 
linear, is only manifested on the lower portion of the 
valves, but in the adult (where the valves only touch at 
the hinge-margin and its opposite edge) is continued up- 
ward, attenuating as it proceeds, even to the auricles. At 
this stage, then, the hiation is conversely dilated on the two 
sides. The snow-white valves, which are very inequilateral, 
are apt to become stained with brown in the larger indi- 
viduals; they are, when adult, less translucent than in 
Loscombii, and although thin and fragile, yet comparatively 
firm in texture. They are chiefly ventricose, if at all so, 
at the umbonal region, but when separated are decidedly 
shallow. The exterior is almost entirely covered with very 
numerous close-set costellar striae, which are more or less 
roughened, and somewhat squamosely so, by concentric lines 
of increase ; occasionally a raised interstitial stria likewise 
presents itself between each of the larger ones. The 
anterior side of the shell at first slopes forward, and 
generally with but little convexity ; after proceeding about 


270 OSTREADA. 


two-fifths of its course, it rather abruptly changes its di- 
rection, and runs subparallel to, but rather more obliquely 
than, the straightish edge of the posterior side. The front 
margin, as far as the curvature, is margined internally by a 
thickening of the substance of the shell. The hinge-margin 
is extremely short, frequently indeed, not more than 
equalling a fifth of the breadth of the valves; the edge 
declines on both sides, and occasionally slopes, in the adult, 
so remarkably behind, as to render the posterior auricle 
obscure, especially when contrasted with the well-defined 
and very acutely-tipped anterior one. The ligamental 
area is large, and, in the full-grown examples, profound ; 
the beaks are very acute and inclined. 

This shell attains to far larger dimensions than either of 
our other species of Lima, individuals that measure an inch 
and three-quarters in breadth, and about one-third less in 
length, being by no means of uncommon occurrence in 
North Britain. The southern examples are far smaller ; 
those which we have taken in Guernsey, as well as those 
from which Turton (the first to introduce the species as a 
native of our coast) derived his description, being scarcely 
more than half that size. We doubt, however, if these 
were adult, as they agree in hiation, etc. with the younger 
individuals of the northern ocean. The want of inter- 
mediate specimens, and the very great rarity of those from 
the south preventing a comparison, have caused the larger 
northern shell to be esteemed a different species. 

The colour of the animal is often very beautiful, varying 
from pale crimson to intense vermilion ; the mantle lobes 
are often tinted with orange. The tentacula are ranged 
in three distinct series, all towards the inner or attached 
edges of the mantle lobes: the innermost row (that nearest 
the shell) is much the shortest, the outermost longest, and 


a 


LIMA. 271 


all are capable of considerable extension, when the cirrhi 
appear as if annulated: the largest cirrhi are those above 
and around the anal region. The branchize are deep 
crimson and large. The belly is carinated, and as well as 
the channeled cylindrical foot, of the same brilliant hue. 
This species can spin for itself a compact nest of byssal 
threads entangling small stones, shells and fragments of 
nullipore ; in the midst of it lies the Lima, resting on a 
smooth inner coating of fibres. As this animal is much 
more frequently taken free than found thus imbedded, and 
as it is a very active creature, swimming through the 
water with great rapidity, it is most likely that this nest- 
making habit is connected with some peculiarity in its 
economy at some particular period of its existence. We 
have never seen any but full-grown specimens contained 
in these curious nests. 

This pretty shell is one of the scarcer inhabitants of the 
British coasts; it occurs in various depths of water. Spe- 
cimens from different localities are often easily distinguish- 
able. Herm, in pools at low-water, alive but scarce 
(S. H.); Penzance, in twenty fathoms, and Anglesey, in 
twelve fathoms (M‘Andrew and E. F.); on the north 
coast of the Isle of Man, in twelve to twenty-five fathoms, 
on scallop banks, frequent, and attaining considerable 
dimensions (EK. F.). Not uncommon among’ nullipores in 
Rothesay and Kames Bays, Isle of Bute, Lamlash Bay, 
Isle of Arran, and Oban, where it is large (Alder) ; Oban, 
—the inflated variety,—alive in fifteen fathoms (M‘An- 
drew and E. F.); off Sana Island, in forty fathoms 
(Hyndman). Loch Carron (Jeffreys). Eda Sound, Ork- 
ney, in fifteen fathoms (Thomas); Belfast Bay, in seven 
fathoms (Portlock). ‘‘ Valves have been found in a recent 
deposit of mud in Belfast Bay, close to the town” (W. 


272 OSTREADZ. 


Thompson). It is found on the coast of the Continent, 
from Norway to the Mediterranean. It is found fossil in 
the Crag. 


PECTEN. BrucGimre. 


Shell oblong or suborbicular, regular, inequivalve, sub- 
equilateral, closed, eared at each side of the hinge ; surface 
smooth or sulcated with radiating, often scaly, ribs, or 
minutely striated and granulated in various directions. 
Beaks approximated. Hinge line straight, with a mar- 
ginal linear ligament, and a central cartilage lodged in a 
triangular pit under the beak of each valve; one valve 
with a byssal sinus. Interior with an entire pallial im- 
pression, and a single large subcentral muscular scar. 

Animal shaped as the shell, mantle freely open, with 
pendant margins bearing (usually two) fringes of tentacu- 
lar filaments, the one series at their fixed, the other at 
their free border. Among the former are ranged globular 
shining ocelli. Nosiphonal tubes. Body large, apiculated. 
Sexes united.* Foot small, cylindrical, with a byssal 
groove, from whence a weak byssus is spun, mostly when 
the animal is young. Mouth surrounded by foliaceous 
leaflets and two pair of labial tentacles which are smooth 
externally, pectinated internally. Branchial leaflets equal, 
each pair partially doubled on itself. 

This beautiful genus, which includes more than one hun- 
dred existing species and a very great number of fossils, 
has several very elegant and useful representatives in the 
British seas. The majority of Pectens are tropical, and 
among them we find the most brilliantly painted of bi- 
valves. They live either solitary or in great assemblages, 


* See Milne Edwards in Ann. des Sc. Nat. xviii. p. 321. 


PECTEN, 218 


at various depths of water, resting in a horizontal position, 
with the less convex and most brilliantly coloured valves 
usually upwards. They are active animals, capable of 
making their way through the water, by flapping their 
valves together, with great rapidity. Those which have 
the upper valve quite flat or concave, have been distin- 
guished generically by the name of Janira, but the tran- 
sitions of form in the genus and the characters of the 
animal, forbid such artificial distinction. 


P. varius, Linneus. 


Kchinated, very rarely, pure white; about 28 much-elevated 
ribs ; ears very unequal. 


Plate L. fig. 1. 


LisrER, Anim. Angl. pl. 4, f. 30.—KwNorR, Délices des Yeux, pt. 
5, pl. 18, f. 2, and pt. 6, pl. 9, f. 4. 

Ostrea varia, Linn. Syst. Nat. ed. 12, p. 1146.—PeEnn. Brit. Zool. ed. 4, vol. iv. 
p- 101, pl. 61, fig. 64.—PuxtrEnry, Hutchins, Hist. Dorset, p. 
36.—Downoy. Brit. Shells, vol. i. pl. 1, f. 1.—Maron and Rack. 
Trans. Linn. Soe. vol. vill. p. 97.—Rack. Dorset Catalog. p. 38, 
pl. 10, f. 1,2, 4,5, 7, 9.—Turr. Conch. Diction. p. 130.—Born, 
Mus. Cees. Vind. p. 104.— Pott, Test. Sicil. vol. ii. p. 163, pl. 28, 
f. 10.—DiLiw. Recent Shells, vol. i. p. 260.—Mawe, Linn. Con- 
chology, pl. 14, f. 4.—Index Testaceolog. pl. 10, f. 31. 

Pecten ,, CuHrmN. Conch. Cab. vol. vii. p. 331, pl. 66, f. 633, 634.—Monr. 
Test. Brit. p. 146.—Turr. Dithyra Brit. p. 214.—F.LEm. Brit. 
Animals, p. 384. — Maceinuiv. Moll. Aberdeenshire, p. 224.— 
Brit. Marine Conch. p. 118.—Lam. Anim. s. Vert. (ed. Desh.) 
vol. vii. p. 147.—Crovcn, Introd. Conch. pl. 12, f. 4—Sowrrsy, 
Conch. Manual, f. 171.—Putirrt, Moll. Sicil. vol. i. p. 84, and 
vol. ii. p. 58.—Sow. Thesaur. Conch. vol. i. p. 76, pl. 19, f. 214, 
218.—Hant. Recent Shells, vol. i. p. 285, pl. 10, f. 31. 

“  monotis, Da Costa, Brit. Conch. p. 151. pl. 10, f. 1,2, 4, 5, 7, 9. 


Among our commonest, but likewise among our most 
beautiful shells, may be reckoned the Pecten varius, the 
infinite diversity of whose colouring has induced the in- 


VOL. II. NWN 


274 OSTREADA. 


defatigable Gmelin to reproduce it under many appel- 
lations in his crude, but laborious compilation.* It is of 
an abbreviated-ovate shape, scarcely at all oblique, and 
almost equivalve. Both valves are moderately convex ; 
the under, which is usually likewise the less darkly co- 
loured, is rather the more shallow, but exhibits a sculpture 
in no way differing from the upper one. ‘The general 
surface is radiated with numerous much-elevated ribs, 
ranging from twenty-five to thirty in number, but usually 
about twenty-eight, the profound interstices between which 
are nearly of the same width as the coste, and, except when 
highly magnified, appear smooth: under the lens, however, 
they more or less distinctly exhibit very delicate striule, 
which upon the umbones are concentrically disposed, but 
near the lower margin run from the sides of the ribs up- 
ward in a somewhat divergent fashion, and usually form 
angles at their junction. The coste are abrupt at their 
sides, and armed upon their rounded tops with erect and 
somewhat vaulted linguiform scales, which are typically 
rather large and not very approximate, and are usually 
abraded near the umbones. The auricles are similarly sculp- 
tured, but the scales upon the larger one of the under 
valve, are more crowded and less elevated. The inequality 
of the auricles is very considerable, the area of the larger 
(which is of rather ample dimensions) beimg at least 
thrice that of the smaller, and its upper or cardinal edge 
about double. The entire length of the hinge-margin 
is equal to, or a little more than, one-half the distance from 
the beaks to the opposite margin. The auricular sinus 
is large, subbiangulated, rather profound, and pectinated 

* According to M. Deshayes, the Ostrea muricata, punctata, aculeata, ochroleuca, 


mustelina, flammea, incarnata, versicolor, described and named by Gmelin from 
almost irrecognizable figures of Gualtier, &c., all belong to this species. 


PECTEN. rag as: 


below. The angle of the larger auricle is acute, of the 
smaller one obtuse. 

The most usual painting is livid or purplish chocolate 
colour, rufous brown, orange, red, and yellow, generally 
mottled, especially towards the umbones, with cloudy 
patches of white, and not unfrequently in the darker ex- 
amples with the echinations of a more orange tint than 
the prevailing ground-colour. The young are often of an 
uniform red, or are pale with streak-like patches of liver 
colour or rufous. The internal colouring is similar to that 
of the exterior but of a paler hue: the hinge-margin is 
not plicated. A beautiful lilac variety is obtainedin North 
Britain, and a pure white one is occasionally taken in 
the Firth of Forth. Specimens are sometimes met with 
(these are usually odd valves), more than two inches and 
a half broad and of nearly the same length; the more 
common proportions (the young are always the less or- 
bicular) are, however, an inch and a half in length, and 
an inch and three-quarters in breadth. 

The animal has the margins of the mantle of consider- 
able breadth ; their free edges are fringed with short white 
tentacula, their fixed borders with both short and long 
ones, the latter fewest, and ranged at regular intervals. 
We have counted about eighteen of these long cirrhi, 
which are usually of a pink hue, on each mantle-margin. 
The mantle-margins themselves are very variable in co- 
lour, sometimes pale pink mottled with white, sometimes 
bright yellow speckled with orange and brown. The 
ocelli are black, and more numerous than the long ten- 
tacles. The body is of a pale cream or yellow hue; the 
branchie of a fawn colour. The foot is short, narrow, 
and white. The mantle-edges lining the auricles have 


short cirrhi only. 


276 OSTREADA. 


The shell is distributed all round the British coasts, in 
some places very abundantly, in others it is comparatively 
scarce, but scarcely any where gregarious. In Zetland it 
appears to be rare, and is on the whole more common 
in the south than in the north. It ranges from three to 
thirty-five fathoms, but is most plentiful in from seven 
to fifteen. It ranges throughout the European seas and 
is yet found rarely in the fossil state, in Pleistocene beds. 


P. niveus, Macgillivray. 


Free, echinated, almost always white ; with from forty to fifty 
distinct and elevated ribs ; ears unequal. 


Plate L. fig. 2, and (Animal) Plate S. fig. 3. 


Pecten niveus, Maceituiv. Edinburgh Nat. and Phil. Journal vol. xiii. (1825), p. 
166, pl. 3, f. 1.—FLemine, Brit. Animals, p. 384.—Brit. Marine 
Conch. p. 250.—Brown, Illust. Conch. G. B. p. 74, pl. 24, 
f. 16.—SowrErsy, Thesaur. Conch. vol. i. p. 77, pl. 19, f£ 223, 
224, 

The general features of this shell are so very nearly 
identical with those of the preceding species, that it is 
only necessary to specify those details in which it differs. 
Of these, the most immediately perceptible is the much 
greater number of the ribs, which range from about forty to 
upwards of fifty, are narrower and more closely disposed, 
and echinated by much smaller scales, whose fragility is 
such that they are partially abraded on almost every spe- 
cimen, and which, upon the young, are, for the most part, 
only visible at the extreme sides. The general shape is ra- 
ther more orbicular than in varius, and the auricles are not 
so disproportionate, the area of the larger one (which is by 
no means of such amplitude as in the previous species) not 
exceeding twice that of the other, and its upper or cardinal 


PECTEN. 277 


edge not being more than half as long again (in the adult) 
as that of the smaller ear. The entire length of the hinge- 
margin, likewise, is proportionately shorter than in varius ; 
and both the external and internal surfaces of the shell 
are in the more typical examples of a pure and uniform 
white. 

The length of a rather large example was two inches 
and an eighth; its breadth was scarcely more than a line 
greater. The proportions are very different in the young, 
the breadth, in a specimen of half an inch wide, exceeding 
the length by about one-fifth. 

The margins of the mantle are ample and of a plain 
white colour: near their free-edges is a row or border of 
very short filaments, fawn-coloured at their bases, and not 
extended beyond the mantle-edge ; at the fixed border im- 
mediately under the edge of the shell is a range of longer 
and more closely set white tentacles, at the bases of 
which are the numerous, small, black ocelli, among 
which at intervals are narrow dusky blotches. The body, 
foot, and branchiz are white. 

Pecten niveus lives moored to Laminaria, the old ones 
chiefly attached to their fronds, the young ones to their 
stalks, as we have seen when taking it alive in fifteen 
fathoms water at Oban (M‘Andrew and E.F.). It was 
first found in the Outer Hebrides by Professor Macgil- 
livray, who distinguished it asa species. It has not been 
observed out of Britam. Mr. Jeffreys has taken it in Loch 
Carron and various other parts of the west of Scotland. 


278 OSTREADZ. 


P. pusio, Pennant. 


Affixed when adult; more or less distinctly marbled ; with 
crowded and prickly costellar strie, which are usually arranged 
so as to alternate in size; interstices extremely narrow, not 
squarely defined. 


Plate L. fig. 4, 5, and LI. fig. 7. 


Lister, An. Angl. pl. 4, f. 31; Hist. Conch. pl. 172, f. 9. 
Ostrea pusio, LINN. Syst. Nat. ed. 12, p. 1146 (probably).—Donov. Brit. Shells, 
vol. i. pl. 34. 

Pecten pusio, PENN. Brit. Zool. ed. 4, vol. iv. p. 101, pl. 61, f. 65. — Turr. 
Dithyra Brit. p. 215, pl. 17, f. 2.— Fiem. Brit. Animals, p. 
385.—Macaituiy. Moll. Aberd. p. 226. — Brit. Marine Conch. 
p- 119.— Sowersy, Genera Shells, Pecten, f. 6.— Puuintprt, 
Moll. Sicil. vol. i. p. 84, and vol. ii. p. 58. — REEveE, Conch. 
Systemat. pl. 114, f. 6.—Sowrrsy, Thesaur. Conch. yol. i. p. 
72, pl. 14, f. 62, 63. 

distortus, DA Costa, Brit. Conch. p. 148, pl. 10, f. 3, 6.— Monr. Test. 

Brit. p. 148, and Suppl. p. 61. — ALpEr, Cat. Northumb., and 
Durh. Moll. p. 77.—LoveEn, Index Moll. Skandin. p. 30. 
Ostrea distorta, PULTENEY, Hutchins, Hist. Dorset. p. 36. 
sinuosa, Matron and Rack. Trans. Linn. Soc. vol. vill. p. 99. — Rack. 
Dorset Catalog. p. 38, pl. 10, f. 3, 6. — Turr. Conch. Diction. 
p- 180.— Ditiw. Recent Shells, vol. i. p. 262.—Index Testa- 
ceolog. pl. 10, Ostrea, f. 34. 
Pecten sinuosus, TurT. Dithyra Brit. p. 210, pl. 9, f. 5. — Fremine, Brit. Ani- 
mals, p. 384.—ForBeEs, Malac. Monens. p. 40.—Mace1LLiv. 
Moll. Aberd. p. 225.—Brit. Marine Conch. p. 116.—Brown, 
Tilust. Conch. G. B. p. 73, pl. 25, f. 2.—Lam. Anim. s. Vert. 
(ed. Desh.) vol. vil. p. 148. 
Hinnites sinuosus, DEsH. Anim. s. Vert. vol. vii. p- 149, note. — SowErpy, 
Thesaurus Conch. vol. i. p. 79, pl. 20, f. 1, 2, 3.—Cuvirr, 
Régne Anim. (ed. Croch.) pl. 77, f. 1. — Brop. Penny 
Cyclop. vol. xvii. p. 359. 
45 pusio, SowERBY, Conch. Manual, f. 173. 
Pecten Isabelle, (FRY.) MacGituiv. (not Lam.) Moll. Aberd. p. 225 (fide Jef- 
freys from type).—Brit. Marine Conch. p. 250 (copied).— 
Browy, Illust. Conch. G. B. p. 132 (do). 
spinosus, BRowN, Illust. Conch. G. B. p. 73, pl. 24, f. 8. 
striatus (fossil) Sow. Min. Conch, pl. 394. f. 2, 4. 


bb) 


3” 


” 


29 


The habits and appearance of this Pecten, which we 
have not ventured to call the pusio of Linnzus, although we 


PECTEN. 279 


believe it to be so, vary so greatly with age, that its former 
division into two or more species can excite but little sur- 
prise and less reprehension. In the young it is free and 
regular, but when mature becomes attached and, from 
adapting its growth to the circumstances of its abiding- 
place, distorted. Consequently it is rather from the younger, 
than from the more aged examples, that, contrary to the 
ordinary rule, we must derive the characteristics of the 
species. At the former stage the contour, which in the 
adult is often orbicular, is manifestly broader than long, 
and the hinder auricle is only about half the length of 
the very large anterior one; whereas in old shells, the 
auricles, being dependent upon situation for their develope- 
ment, are occasionally small, and sometimes, the growth 
being checked in front but permitted behind, are of almost 
equal dimensions. The colouring is very variable: at 
times the exterior is entirely red or white, at times marbled 
with patches of either tint ; frequently this painting lingers 
upon the umbones, whilst the lower disk is either mottled 
or marked with wavy patches of nut-brown, or brownish 
liver-colour, on a whitish ground; more usually, however, 
the umbones do not differ in their painting from the rest of 
the surface. That which peculiarly distinguishes the species 
is its sculpture; this, however, is wholly obsolete, save 
on the free umbones, in the attached lower valve, which 
moulds itself to the peculiarities of the rock or shell to 
which it is affixed, and is consequently almost invariably 
distorted and sinuous in appearance ; the form of the upper 
valve assimilates itself likewise to that of the lower, and 
exhibits corresponding gibbosities and indentations: the 
portion actually attached is destitute of colour. Extremely 
numerous costelle (we have counted as many as forty in 
the young, and may say nearly twice that number for the 


280 OSTREADA. 


adult), armed more or less closely with fragile laminar 
spines and vaulted or prickly scales, radiate from the um- 
bones to the ventral margin, intermediate smaller ones 
starting up in the interstices directly the divergence of the 
larger ones permits their developement. An alternation of 
larger and smaller costellz is thus established. The inter- 
stices, previous to the commencement of the intermediate 
little ribs, exhibit, when perfect, somewhat concentric la- 
minar wrinkles, but no microscopic chasing discovers itself 
under a lens of high power. The ears are well defined 
below, and densely covered with echinated costelle; the 
auricular sinus is subbiangulated, rarely profound or large 
in the adult, but almost always more or less indicated ; 
typically the cardinal angle of the front auricle is acute, 
of the hinder one obtuse. An example that measures two 
inches or an inch and three-quarters in width may be 
regarded as a large individual, the majority of specimens 
not averaging an inch anda half. It is difficult to deter- 
mine which valve is the less shallow (neither is very convex, 
and both are moderately strong); but the upper is gene- 
rally regarded as rather the flatter. The interior, which 
is not at all nacreous, is either white or partakes of the 
external colouring. 

The animal is very similar to that of P. varius; the 
long cirrhi of the fixed margins of the mantle appear to be 
longer and the eyes rather larger than in that species. The 
mantle is most usually of a yellow hue, mottled or blotched 
with brown; the branchiz of a fawn-colour, and the body 
of a pale pink tint. 

It is generally distributed around our coast, ranging from 
low-water mark, where it occurs at Herm attached to the 
under-surface of rocks, whilst the young are free in the 
neighbouring pools—(S. H.)—to a depth of fifty, sixty, and 


PECTEN. 281 


even ninety fathoms, as we have found it in the Hebrides 
and Zetlands (EH. F.) It is most plentiful in from fifteen 
to twenty-eight fathoms. The young ones seem to be 
always free or moored by their byssus to corallines and 
sea-weeds, and old examples almost always attached, glu- 
ing their valves, by a process as yet not understood, to the 
surfaces of stones, shells, and laminaria-roots, and assuming 
consequently strange distortions of shape. 

It ranges throughout the European seas, and is found 
fossil in the Upper Tertiaries of England. 


P. srriatus, Miiller. 


Suborbicular, transparent, not ribbed ; with minutely squami- 
ferous radiating costellar striz ; ears not very unequal, the auri- 
cular sinus distinct. 


Plate LI. fig. 1 to 4, and (Animal) Plate §, fig. 2. 


Pecten striatus, MULLER, Zool. Danic. pl. 60, f. 3 to 5.—ALDER, Cat. Northumb. 
and Durh. Moll, p. 77. —Lovin, Index Moll. Scandinay. p. 31. 
Pallium vitreum (partly), CuEmn. Conch. Cab. vol. vii. p. 335, pl. 67, f. 637, 
Dac: 
Ostrea fuci, GMELIN, Syst. Nat. p. 3327.—Ditiw. Recent Shells, vol. i. p. 258° 
—Index Testaceol. pl. 10, f. 27 ? (copied from Pecten reticulatus, 
Chemn. Conch. cab. vol, xi. (p. 263) pl. 207, f. 2039, 2040.) 
Pecten aculeatus, JEFFREYS, Conch. and Malacolog. Magaz. vol. i. p. 40.—Brit. 
Marine Conch. p. 249, f. 30.—SowxErgy, Thesaur. Conch. 
vol. i. p. 71, pl. 13, f. 47. 
Landsburgi, SmirH, Mem. Werner. Soc. vol. viii. p. 106, pl. 2, f. 2.— 
Brown, Illust. Conch. G. B. p. 73, pl. 25, f. 8.— Han. 
Recent Shells. vol. i. p. 282. 
5 fuci, THompson, Ann. Nat. Hist. vol. xviii. p. 385. 
5  vimulosus, PuiiipPi, Moll. Sicil. vol. ii. p. 60 (fossil) ? 
35  Spinosus, JOHNSTON, Trans. Berwick Nat. Club. 


3° 


This beautiful and fragile bivalve is of such extreme 
tenuity as to be often actually transparent. Its shape is 
nearly circular, but rather broader than long; its posterior 
side is decidedly the shorter ; there is, however, no marked 

VOL. II. 00 


282 OSTREADA. 


bulging out at the hinder extremity. The valves are 
shallow, but nearly equally convex ; their exterior is shin- 
ing, and microscopically chased with dense and peculiarly 
irregular divergent wavy radiating striule, which, when 
examined under a very powerful glass, often appear subar- 
ticulated. The upper valve (whose colouring is likewise 
the darker) exhibits also very numerous but not much 
elevated strie, which run from the beaks to the ventral 
margin, and are echinated (at least in the younger speci- 
mens) by short broad and minute prickly scales, which 
are most apparent towards the lower margin, but, where 
abraded, show traces of their former presence by the some- 
what articulated or catenulated appearance of the striz. 
This sculpture, which extends likewise to the auricles, is 
obsolete or very obscure upon the lower valve, where 
microscopic concentric lines more or less decussate and 
shagreen the minute striule. The colouring and style 
of painting is not unlike that of figrinus, consisting of 
whitish streaks, clouds, or spots, on a ground of brownish 
or somewhat livid red, varying in intensity from chocolate 
to pale brownish flesh-colour ; snow-white flakes or minute 
specks occasionally augment the beauty of the pattern. 
There exists also (as in most Pectens) a colourless variety. 
The dorsal slopes are incurved and rather short; the 
hinge-margin, which is almost invariably equal to half the 
length of the shell, often exceeds that proportion; the 
ventral margin is rather broadly rounded (in the adult) ; 
the apices of the valves acute and prominent. The 
auricles, which are well defined in both valves, are very 
unequal. The posterior one, although not very small, is 
only half as long as the other; its base, however, reaches 
as low down as that of the hinder one; its angle is 
decidedly obtuse; its side straightish, and occasionally 


PECTEN. 283 


slightly convex. The anterior auricle is decidedly large, 
but very manifestly shorter in the upper valve; its angle 
is a right angle, and its sinus rather large, profound, finely 
pectinated, and angular below. The interior of the shell 
displays no peculiarity in hinge or painting; the latter, 
from the thinness of the shell, being that of the exterior ; 
the margin is quite entire. 

Our largest specimen measured ten lines in width, and 
was slightly inferior (not quite a line) in length; the 
middle-aged examples are the more orbicular. 

The animal has a white-margined mantle, marked with 
distant perpendicular stripes of Sienna-yellow; on the 
fixed edges of the mantle-margins are the white cirrhi, 
and among their bases conspicuous blue-black ocelli, which, 
when very highly magnified, are seen to have crimson 
centres; the shorter cirrhi at the free edge of the mantle 
are white. The branchie are yellowish-white, and the 
body is of a bright orange-yellow. 

This pretty shell, first described as British by Mr. Smith 
of Jordan Hill, and named by him after our esteemed 
friend, the Rev. David Landsborough, appears to have 
been formerly confounded on our shores with tigrinus. It 
is a species of boreal origin, and consequently most com- 
mon on the Scottish shores, and near the outliers of the 
glacial sea. On the English coast it is very rare, but has 
been taken off Scarborough (Bean); in thirty fathoms, 
thirty-five miles off Northumberland (King); in fifty 
fathoms, on the same coast (Howse); at Whitburn 
(Abbes) ; and Newton (Embleton). On the west coast 
of Scotland it is frequent in the Clyde district and the 
Hebrides ; it occurs also among the Zetlands and Orkneys. 
The following Scottish localities will show its range :— 
Orkney, twelve fathoms; Oban and Skye, in twenty 


284 OSTREADA. 


fathoms; off Copenhaw Head and Loch Ranza in forty 
fathoms. Ten miles from Fair Isle in sixty fathoms. 
In fifty fathoms moored to stones on the Ling banks 
forty miles to the west of Zetland. In ninety fathoms 
off Mull (M‘Andrew and E. F.). 

On the Irish Coast it has been taken in Strangford 
Lough (W. Thompson and Hyndman) ; in Birterbuy Bay 
on the west coast (Barlee) ; on rocky ground east of Cape 
Clear in from forty to forty-five fathoms (M‘Andrew) ; 
and from the Nymph Bank (Warren). It ranges along 
the Scandinavian shores to Finmark (Lovén). 

The Pecten furtivus of Lovén (Index Moll. Skandinay. 
p- 31) has been dredged in Zetland; at Lerwick in 
forty and fifty fathoms (Jeffreys); Loch Fyne (M‘An- 
drew); Galway (Barlee); and Exmouth (Clark). It dif- 
fers from the typical striatus in being suborbicular, 
and usually of a more opaque texture; is either with- 
out the aculeated striz, or has fewer and only displays 
them fully at the sides and near the margin. Its micro- 
scopic chasing, likewise, is much more regular (as in 
tegrinus), and in most examples is closely decussated by 
concentric lines. The front auricle of the upper valve is 
somewhat incurved at its base, and above is very nearly 
coextensive with that of the under one; whilst in the 
typical form the entire lateral edge of the superior front 
auricle is comparatively straight, and above exhibits the 
opposing auricle stretching out beyond it. All these 
characters are rarely present in the same example, and 
indeed blend so imperceptibly with the normal features of 
striatus, that we are not prepared, after having observed 
the remarkably wide range of variation permitted to its 
British congeners, to accede at present to its separation 
from that species. 


PECTEN. 285 


P. tiertnus, Miiller. 


Decidedly broader than long, with or without radiating folds, 
never echinated ; one of the ears almost rudimentary. 


Plate LI. fig. 8 to 11. 


Pecten tigrinus, MtsuLER, Zool, Dan. pl. 60, f. 6, 7, 8—ALDER, Cat. Moll. 
Northumb. and Durham, p. 77.—Drsu. Anim. s. Vert. vol. 
vii. p. 155.—Lovin, Index Moll. Scandinay. p. 31. 
»  Oobsoletus, PENN. Brit. Zool. ed. 4, vol. iv. p. 102, pl. 61, f. 66.— Donoy. 
Brit. Shells, vol. i. pl. 1, f. 2,— Monv. Test. Brit. p. 149, and 
Suppl. p. 57.—Turr. Dithyra Brit. p. 213, pl. 9, f. 6.— 
FLEemine, Brit. Anim. p. 385.—Maceitiv. Moll. Aberd. p. 
226.—Brit, Marine Conch. p. 118.—Brown, Illust. Conch. 
G. B. p. 72, pl. 24, f. 6. — SowErsy, Thesaur. Conch. vol. i. 
p. 71, pl. 14, £.74, 75, 79.— Hanu. Recent Shells, vol. i. 
p. 282, pl. 10, f. 37. 

“5 levis, PENNANT, Brit. Zool. ed. 4, vol. iv. p. 102.—Monrv. Test. Brit. 
(not Suppl.) p. 150, 579, pl. 4, f. 1.—Turv. Dithyra, Brit. p. 
212.—Brit. Marine Conch. p. 117.—Brown, Illust. Conch. 
Geb apa ple 245itende 

»  parvus, DA Costa, Brit. Conch. p. 155. 

Ostrea tigrina, GMELIN, Syst. Nat. p. 3327.—Diiw. Recent Shells, vol. i. 
p- 258.-—Index Testaceolog. pl. 10, f. 26. 
Pecten domesticus, CHEMN. Conch. Cab. vol. xi. p. 261, pl. 207, f. 2031 to 2036. 
Ostrea obsoleta, MAToN and Rack. Trans. Linn. Soe. vol. viii. p. 100. —Turr. 
Conch, Diction. p. 183. — Dituw. Recent Shells, vol. i. 
p. 263.—Index Testac. pl. 10, f. 37.—Mawe, Linn. Conchol. 
pl. 14, f. 6. 

3 levis, Maron and Rack. Trans. Linn. Soc. vol. viii. p. 100, pl. 3, 
f. 5. — Dititw. Recent Shells, vol. i. p. 263. — Index 
Testaceolog. pl. 10, f. 38. 

Pecten Armoricanus, CHENU, Ill. Conch. Pecten, pl. 39, f. 1, 2, 3. 


As this shell exhibits the strange phenomenon of being 
sometimes smooth, at other times most distinctly ribbed, 
it was naturally divided into two or more species at a 
period when, the conchological fauna of North Britain 
being but little known, the Pecten tigrinus was considered 
one of our scarcest shells. The zealous labours of many 
naturalists in the Northern portion of our Islands, and the 


286 OSTREADA. 


much more frequent use of the dredge, have rendered 
this bivalve a comparatively common one, and furnished 
us with connecting links between the two chief varieties. 
The shape is suborbicular, but rather broader than 
long, the texture moderately strong, and the surface dull, 
or scarcely at all shinmg. Both valves are convex (yet 
not quite equally so), and typically rather compressed ; 
they are alike in sculpture, and frequently in colouring 
also. The exterior appears, under the lens, to be co- 
vered with most minute subradiatingly divergent curved 
wavy striule, which again, under a still higher power, 
exhibit microscopical concentric lines (especially in the 
more convex valve), decussating them either wholly or at 
the sides. Sometimes the surface is otherwise smooth, 
sometimes there is a marginal belt of narrow and very 
closely disposed depressed radiating costelle ; occasionally 
these latter extend over the whole shell with or without 
the presence of about five principal radiating ribs, which 
are rounded, generally broad, and variable in amount of 
elevation. At times the coste are alone present, the 
costellee, or raised sulci, being obsulete; more frequently 
two or three of these intervene between each rib. The 
auricles are excessively unequal, well defined, scarcely 
subrectangular, costellated, unarmed, and sometimes lat- 
ticed ; the anterior one is large; the posterior one, whose 
upper edge is not half the length of the front one, is 
almost rudimentary. The auricular sinus is very narrow, 
forming a very acute angle at its summit; it is not very 
profound, and is very delicately pectinated below. The 
hinge-margin is found, when measured, to be equal to half 
the width of the shell, though scarcely appearing so to the 
eye. The dorsal edges are rather long and much sloping. 
The interior is usually of a whiter cast than the external 


PECTEN. 287 


colouring: its hinge-margin is not peculiarly plicated : its 
rim is almost always crenated. 

The painting is very beautiful, and displays an infinity 
of patterns; the mass of individuals, however, are of a 
brownish red, and usually mottled or variegated with 
whitish patches, streaks, spots, festoons, clouds, or 
specks, occasionally also with chocolate-coloured rays or 
stains, and generally with a brighter orange-red tint upon 
the acute beaks. One of the most beautiful specimens we 
possess is of an uniform lilac tint in one valve and snowy 
white upon the other; in another specimen wavy fillets of 
livid red encircle the more convex of the two white valves; 
in a third individual three yellow rays are apparent upon a 
ground of purplish liver-colour. A very charming and 
rare variation displays linear fillets of white upon a ground 
of reddish chocolate colour. 

One of our larger specimens measured nearly an inch in 
breadth, and only one line less in length ; three quarters of 
an inch, however, is a fair average width for examples. 
We may remark, also, that in the ribbed variety, the lower 
margin is so waved as occasionally to become pentagonal ; 
and sometimes is so suddenly bent in, that the shell as- 
sumes the appearance of a shallow box. 

The animal has a white margined mantle, mottled with 
dusky or brown rays. The ocelli are brown. The body 
is usually of a bright red colour, occasionally of a creamy 
white. It is a favourite food of flat-fish. 

This pretty shell is found on all our coasts, though much 
scarcer in some localities than in others. It ranges from 
twelve to sixty fathoms, frequenting sea-bottoms of shells, 
gravel and sandy mud. In from eighteen to twenty-five 
fathoms is its favourite depth. 

It ranges throughout the Celtic and North European 


288 OSTREAD A. 


seas, and is found fossil in the red and mammaliferous 
crags.* 


P. panicus, Chemnitz. 


With from four to ten radiating folds; white, or speckled with 
white on a ruddy ground : hinder auricle not obsolete, at least 
equal in length to half the anterior one, when small forming an 
acute angle. 


Plate LII. fig. 1, 2, 7, 8, 9, 10. 


Pecten septemradiatus, MiiLer, Zool. Dan. Prodromus (1776), No. 2992 (fide 
Loyén, p. 31). 
» _ triradiatus, MULLER, Prodromusand Zool. Dan. vol. ii. p. 25, pl. 60, f. 1, 
2 (fide Loven and Chemn.). 
Pseud-Amusium, CHEMN. (not Klein) Conch. Cab. vol. vii. (1784), p. 298, pl. 63, 
f. 601, 602. 


* We are at a loss to discover what was regarded by Montagu in his Sup- 
plement (p. 61.—FLxemine, Brit. Anim. p. 385,—Ostrea levis, Turt. Conch. 
Dict. p. 131.) as the P. levis of Pennant, which latter is thus imperfectly charac- 
terised :—“ Both shells convex, with unequal ribbed ears ; the rest of the shell 
entirely smooth, very small—Anglesea: ” and is probably tégrinus of this work. 
It appears that the author of the “ Testacea Britannica” possessed two specimens, 
the larger of which, measuring slightly more than half an inch, was taken in 
Falmouth Harbour, (this was possibly exotic, for the locality is a suspicious one,) 
the smaller (and this was possibly the fry of P. maaimus, or some other indi- 
genous species, and not the individual described) from the coast of Deyon among 
Sertulariz and Nullipores. He states that the shell was nearly equal in length 
and breadth, so thin as to be semitransparent, was whitish or of a pale ash-colour, 
not shagreened, but quite smooth, except the mere wrinkles of increase, and had 
one of its auricles of ample magnitude, whilst the other was small and a little 
striated in a longitudinal direction. However insufficient this language proves 
for indicating with any certainty what particular species was meant out of the 
hundred or more known members of the genus, it nevertheless describes features 
which are not combined in any native shell we are acquainted with. Some 
naturalists have surmised that it was the similis of Laskey, but that gen- 
tleman expressly declares (Mem. Wern. Soc. yol.i.) that the reception of a speci- 
men from Montagu (a third or one of the original types ?) had dispelled his pre- 
vious conjecture of the specific identity of the two shells: moreoyer, the yery 
different auricles forbid this hypothesis,—in truth, a worn ¢égrinws would agree 
far better with the brief diagnosis. 


PECTEN. 289 


Ostrea hybrida, GMELIN, Syst. Nat. (1788), p. 3318 (not synonymy; from Chem- 
nitz, f. 601, 602). 
triradiata, GMELIN, Syst. Nat. p. 3326.—Dixtiw. Recent Shells, vol. i. 
p- 264, (Both from Miiller). 
»  septemradiata, GMELIN, Syst. Nat. p. 3327 (from Miiller), 
Pecten Danicus, Cuzmn. Conch. Cab. vol. xi. (1795) p. 265, pl. 207, f. 2043.— 
Sowerey, Thesaur. Conch. vol. i. p. 61, pl. 12, f. 16, and pl. 
17, f. 187. Hanu. Recent Shells, vol. i. p. 277. 
Ostrea inflexa, Pot, Test. Sicilix, vol. ii. p. 160, pl. 28, f. 4, 5 (probably). 
»  clavata, Pout, Test. Siciliz, vol. i. p. 16], pl. 28, f. 17 (probably). 
5, corallina, Pout, Test. Sicil. vol. ii. p. 164, pl. 28, f. 16 (probably).— 
Cosra, Test. Sicil. p. 51 (do.).—Ditiw. Recent Shells, vol. 
i. p. 255 (from Poli). 
Peeten adspersus, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 186.—JEFFREYS, 
Ann. Nat. Hist. vol. xix. p. 313.—Puttippt, Moll. Sicil. vol. 
i. p. 82, and vol. ii. p. 57. 
» _ pes-felis, LAM. Anim. s. Vert. (ed. Desh.) vol, vii. p. 140 (an part, not 
synonyms) ?—Jzrrreys, Ann, Nat. Hist. vol. xix. p. 313.— 
Puriert, Moll. Sicil. vol. i. p. 84, and vol. ii. p. 58 (probably ; 
but not synonyms). 
? 4, glaber, Mont. Test. Brit. Suppl. p. 60.—Turron, Dithyra Brit. p. 211.— 
Brit. Marine Conch. p. 117.—FLEmine, Brit. Animals, p. 384. 
—Brown, Illust. Conch. G. B. p. 73, pl. 25, f. 3, 4. 
? Ostrea glabra, TuRTON (not Linn.) Conch. Diction. p. 132. 
Pecten Dumasii, P AYRAUDEAU, Cat. Moll. Corse, p. 75, pl. 2, f. 6, 7. JEFFREYS, 
Ann. Nat. Hist. vol. xix. p. 313. 
»  nebulosus, BRowN, Edinb. Journl. Nat. Hist. (ed. Macg.) vol. i. (Nov. 
1835), p- 9, f. 1; Tlust. Conch. G. B. p. 72, pl. 22, f. 17. 
Jamesoni, Situ, Memoirs Werner. Soc. vol. viii. p. 106, pl. 2, f. 1.— 
Brown, Illust. Conch. G. B. p. 73, pl. 25, f. 7. 
Encyclopédie Méthodique, Vers., pl. 212, f. 6. 


” 


”° 


Following the example of Dr. Philippi, but after a long 
and independent scrutiny, we have united under this 
epithet forms and sculpture so apparently distinct that he 
who possesses the more characteristic examples of each 
variety, yet owns not likewise those intermediate links, 
whose existence, an examination of all the great cabinets of 
England has enabled us to ascertain, will assuredly dissent 
from our conclusion. 

The colouring, which pervades all the varieties (the 
albino excepted), is of a lighter or darker brick or ruddy 


VOL. II. 1 1 


290 OSTREADA. 


flesh-colour, diversified in the more characteristic specimens 
with pale or whitish markings, which vary infinitely in 
number, size, shape, and conspicuousness. This painting is 
generally replaced in the lower valves by a white or paler 
tint, usually, however, displaying the more characteristic 
painting upon the umbones and costal interstices. A 
peculiar dull pearly-white gloss distinguishes the interior of 
the more mature individuals; the younger shells, from their 
thinness, exhibit more or less of the external hue and 
pattern. The valves are more or less round, rather thin, 
moderately and nearly equally convex, and rayed with 
from four to ten (five or seven are the most usual) unarmed 
rounded and unequal ribs, which vary much in elevation, 
expansion, and distance from each other, but are commonly 
more abrupt and angular above, more dilated and depressed 
below. In the thinner and more ordinary form (of this a 
live but perfectly colourless individual is in the cabinet of 
Mr. Barlee) the surface is smooth, and the shape, owing 
to the bulging out of the lower posterior portion, is inequi- 
lateral and oblique; the ribs are usually six or seven in 
number, and owing to the gentle declination of their sides 
give an undulating appearance to the exterior. The dorsal 
slopes are but trifling, and the general contour nearly 
circular ; the auricles are comparatively subequal, rather 
large, inclined to be rectangular, and smooth or striated ; 
the sinus is short, shallow, and scarcely angular. Certain 
individuals of this form exhibit under the microscope a 
sculpture analogous to that of tigrinus, but still more 
minute, with the radiating lineoles less divergent, and the 
concentric wrinkles more conspicuous. We regard these, 
however, as exceptional. 

The variety Dumasii is so aberrant, that it was only 
after protracted scrutiny and the comparison of many 


PECTEN. 291 


specimens, that we ventured to decide upon uniting it with 
the more typical form. It is almost invariably smaller, 
with its surface wholly or partially sculptured with radi- 
ating strize; its ribs, which are more frequently five than 
six in number, strongly, and rather abruptly elevated, 
and its hinder auricle very decidedly the smaller one. In 
some of the younger individuals, the very delicate wavy 
concentric elevated wrinkles which cross the striae, give a 
slightly squamular or at times a subcancellated appearance 
to the shell. The white speckles are not so diffused as in 
the previous form, but are generally visible on one, at least, 
of the umbones. In the very beautiful example figured 
(belonging to Mr. Barlee, whose indefatigable exertions in 
collecting, have rendered many of our once scarcer species 
comparatively common), some of the interstitial strie are 
crested with small spinous scales. 

Intermediate between the two, comes a third variation, 
which more closely approaches the former, but differs in 
being stronger, more equilateral, and more frequently 
striated ; its ribs are more prominently defined (and in the 
young are subangular); its dorsal slopes more rectilinear ; 
its hinder auricle, likewise, is rather smaller in proportion, 
more incurved laterally, and with its sinus (in the young) 
more angulated and better indicated. 

A moderately sized specimen of the typical form 
measured. an inch and five lines in length, and an inch and 
six lines and a-half in breadth: its hinge-margin was equal 
to exactly one-half the length of the shell. The dimensions 
of the largest individual noticed by us, of the second variety, 
were an inch and three lines for the length, and one line 
more for the breadth; the hinge-margin measured under 
seven lines, thus causing the auricles to be shorter in pro- 


portion to the general area. 


292 OSTREADA. 


The Pecten glaber of Montagu,* taken by Mr. Laskey 
near Dunbar, agrees better with this than with any other 
of our known native species ; neither figure (Suppl. pl. 28, 
f. 6) nor description (both, we believe, taken from a single 
valve) being absolutely at variance with one of the many 
varieties of this polymorphous shell. So many of the 
supposed Dunbar species having turned out to be foreign, 
this too may possibly prove an exotic Pecten; never- 
theless, we cannot, after studious examination, ascribe 
the species in question, with positive certainty, to any 
member of this extensive genus. As to the glaber+ of 
Pennant (Brit. Zool. ed, 4, vol. iv. p. 102; copied, Monr. 
Test. Brit. p. 150), his description is so brief and imade- 
quate, that unaccompanied as it is with any representa- 
tion, its determination must be purely conjectural; it 
certainly does not appear to be identical with that of 
Linnzeus, which is a well known species of the Mediter- 
ranean. 

This beautiful shell was first announced with certainty as 
a British species by Captain Thomas Brown, who described 


* “ Mottled with rufous brown and yellow, thin, and nearly smooth, but not 
glossy ; it has seven rounded rays, not much elevated: the ears are nearly equal, 
and large, one is reticulated, the other only striated. The inside is sin- 
gularly marked with twenty-one slender rays, the sixteen middle ones are 
placed in fours ; that is to say, there are four rays between the sulci that form 
the rays on the outside, and the two middle of these series of quadruplicate rays 
approximate ; the others are remote: the colour is paler than the outside, except 
at the upper part about the hinge. Length, three quarters of an inch, breadth 
rather less. In the specimen before us there is some slight appearance of interme- 
diate rays in the depressions that separate the evident ones, and which are 
formed by the sulci between the approximate rays on the inside. Those who are 
fortunate enough to obtain the shell will observe by the assistance of a pocket 
lens, that it is most minutely striated concentrically, but does not possess any 
longitudinal striz, like P. obsoletus.” (Mownr. Test. Brit. Suppl. p. 60.) 

+ “ P. with a very thin shell, fifteen faint rays, equal ears. The inner side of 
the shells marked with rays, divided by a single sulcus. Anglesea. A scarce 
species. Small.” 


PECTEN. 293 


it, and exhibited specimens from the Clyde, at the Edin- 
burgh meeting of the British Association. It has since 
been taken by Mr. Smith, Mr. M‘Andrew, Mr. Jeffreys, 
Mr. Barlee, and others, in many localities among the 
Hebrides. The following will show its range in depth. 
Lismore and south of Skye in twenty fathoms; Armadale 
in twenty-five fathoms; Loch Fyne and Loch Ranza in 
forty fathoms; Mull, in ninety fathoms. Off both east 
and west coasts of Zetland it has been taken in eighty, 
and in one instance at the depth of one hundred fathoms 
(M‘Andrew). The variety Dumasii has been taken in 
Skye (Jeffreys), and Oban (Barlee). 


It is found on the shores of Scandinavia, and in the 
Mediterranean. 


P. simiuis, Laskey. 


Minute, longer than broad, quite smooth, bulging out at one 
of the sides. 


Plate LIL, fig. 6, and (animal) Plate §, fig. 1. 


Pecten similis, LASkEY, Mem. Werner, Soe. vol. i. p. 387, pl. viii. f. 8. — 
FrieminG Brit. Animals, p. 385.—Maceririyr. Moll. Aberd. 
p- 227.—Browy, IIlust. Conch. G. B. p. 73, pl. 25, f. 5, 6. 
Ostrea tumida, Turt. Conch. Diction. p. 1382. 


Pecten tumidus, Turt. Dithyra Brit. p. 212, pl. 17, f. 3.—FLEmine, Brit. Anim. 
p- 384.—Brown, Illust. Conch. G. B. p. 73.—HAnz. Recent 
Shells, vol. i. p. 275.—LoveEn, Index. Moll. Scand. p. 32. 


This little bivalve may readily be distinguished from the 
other smooth British Pectens, by its length being at least 
equal to its breadth. It is small, suborbicular, very thin 
and fragile, transparent, compressed, and more or less 
shining ; the valves, though equal to each other in con- 
vexity, are scarcely of the same breadth, the upper, for the 


most part, projecting rather beyond the ventral margin of 


294 OSTREADA. 


the lower valve. The painting of the upper valve is varia- 
ble, yet usually consists of bright red markings upon a 
pale or yellowish-white ground, exhibiting some diversity 
of arrangement, and very often displaying a mottled ap- 
pearance, with frequently, too, a few narrow interrupted 
rays of blood-red and occasionally opaque white amorphous 
patches. Sometimes the pattern is composed of white 
and scarlet zigzags disposed somewhat concentrically upon 
a pale horn-coloured ground. The lower valve is either 
whitish or faintly exhibits the hues of the superior one. 
Neither striz, ribs, radiating folds, nor microscopic chasing 
are visible, the entire surface being perfectly smooth, with, 
at most, faint indications of concentric lineoles. The sides 
are unequal; the anterior is the more produced, and 
slightly the narrower at its projecting termination ; the pos- 
terior is the shorter and the more broadly rounded at its 
extremity. The auricles are rather large and not very 
unequal, have their lateral edges convex, and their upper 
angles, which are both of them rounded off, rather more 
than right angles. The hinder ears are not well defined 
at their commencement: that of the upper valve, although 
larger in area, scarcely surpasses the other in length; the 
front one of the superior valve rather curls upward at its 
top. The auricular sinus is small and rather shallow, but 
acutely angular below, and well indicated. The hinge- 
margin is very long, being considerably more than half 
the length of the shell. The extension of the posterior 
auricle causes the lateral outline of that side of the shell 
to appear peculiarly abrupt and but little indented, the 
outline of the ear being united to that of the body in 
almost a continuous curve. 

Few of our British specimens measure much more than 
a quarter of an inch in diameter. The P. Greenlandicus 


PECTEN. 295 


of Sowerby (Thesaur. Conch. vol. i. p. 57, pl. 13, f. 40) 
is very closely allied to this species. 

The animal has a fawn-coloured mantle marked with 
patches and lines of orange and black; the edges nearest 
the shell are furnished with white or pale-yellowish cirrhi, 
rather thick and long in proportion to the size of the 
species. The ocelli are large, distant, and comparatively 
few, pearly and ringed with jet. The body and foot 
are of a brilliant orange, and the branchial leaflets are 
lineated with black. It is a very active and irritable 
creature jumping and swimming about in confinement 
with great vivacity. All its activity is needed to enable 
it to escape from its enemies, since haddocks greedily 
devour it. 

This pretty little Pecten was first observed by Laskey, 
who took it in the Frith of Forth. <A slight variety taken 
by Turton attached to a Serpula tubularia in Torbay, 
was named by that author P. tumidus. It has since been 
found in many localities, usually in deep water; Penzance, 
alive in twenty fathoms, and Plymouth in twenty-five 
fathoms (M‘Andrew and E. F.). Isle of Man, moored 
to corallines in twenty-five fathoms (EH. F.). Taken from 
the roots of corallines on the Northumberland and Dur- 
ham coasts (A. Hancock). In twenty-five fathoms, stony 
ground, Coquet and northwards to sixty fathoms off 
Trouphead, where they are numerous and free (‘Thomas). 
In numerous localities among the Hebrides, in from 
eighteen to fifty fathoms water, also in Zetland (M‘Andrew 
and EK. F.). Off Lerwick in forty fathoms; at Ullapool 
off Skye, and in Loch Fyne (Jeffreys). In four fathoms, 
Shapinsha, moored to corallina, among thousands of Rissoze, 
and in two fathoms, Stromness, moored to D. aculeata 
(Thomas; who observes that they can quit their moor- 


296 OSTREAD A. 


ings when they like). Off Cape Clear in sixty fathoms 
(M‘Andrew) ; off entrance of Belfast Lough in thirty 
to thirty-five fathoms (Thompson.) It ranges throughout 


the European seas, and is found fossil in the coralline 


crag (Wood). 


P. maximus, Linnezeus. 


Very inequivalve ; upper valve concave at the umbones ; under 
valve very convex. 


Plate XLIX. 


Lister, Anim. Angl. pl. 4, f.29; Hist. Conch. pl. 163.— 
Knorr, Delices des Yeux, pt. 2, pl. 14, f. 1. 
Ostrea maxima, LINN. Syst. Nat. p. 1144; Fauna Suecica, p.520,—PULTENEY, 
Hutchins, Hist. Dorset, p. 35.—Donoy. Brit. Shells, vol. ii. 
p. 49.—MarTon and Rack. Trans. Linn. Soc. vol. viii. p. 96; 
Dorset Catalog. p. 37, pl. 9, f. 3.—Turr. Conch. Diction. 
p- 128.— Born, Mus. Ces. Vind. p. 98.—Dittw. Recent 
Shells, vol. i. p. 247.—Index Testaceolog. pl. 10, f. 1. 
Pecten maximus, PENN. Brit. Zool. ed. 4, vol. iv. p. 99, pl. 59, f. 61.—Monr. 
Test. Brit. p. 143.—Turvt. Dithyra Brit. p. 207.— FLEMING, 
Brit. Anim. p. 383.—M accituiv. Moll. Aberdeens. p. 223.— 
Brit. Marine Conch. p. 115.—Brown, Illust. Conch. G. B. 
p. 71, pl. 25, f. 1.—Cuemn. Conch. Cab. yol. vii. p. 268, pl. 
60, f. 585.—Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 129. 
—Croucn, Introd. Lam. Conch. pl. 12, f. 3.—SowERsy, 
Thesaur. Conch. vol. i. p. 45, pl. 15, £98 to 100.—Hanu. 
Recent Shells, vol. i. p. 268, pl. 10, f. 1. 
“ vulgaris, DA Costa, Brit. Conch. p. 140, pl. 9, f. 3. 
ce levis, MaceiLuiv. Moll. Aberdeen. p. 227 (probably). 


The great edible Scallop is a large and handsome shell. 
It is suborbicular, strong, occasionally heavy, and very in- 
equivalve; the lower valve being ventricose, whilst the upper 
one is shorter at the ventral margin, flat but depressed at 
the umbo in the adult, and entirely concave in the young. 
From about fourteen to sixteen broadish and rounded 
ribs diverge from the umbo of the lower or more con- 


PECTEN, 297 


vex valve; these are but moderately elevated, and are 
rather wider than their interstices, which are simply 
concave, and, equally with the coste, sculptured with 
large and distinct elevated radiating striz. These lat- 
ter, however, are entirely absent upon the umbones of 
the adult, and are not developed in the younger shells. 
Similar striz appear upon the flattened valve, but, to- 
gether with the cost, disappear upon the depressed umbo. 
As the flat interstitial spaces of the upper valve corre- 
spond to the broad ribs of the lower one, the converse 
of the relative proportions of ribs and interstices here 
prevails, the former (whose sides are abrupt, and whose 
tops are but slightly rounded) being much narrower 
than the latter, where the delicate crowded lamellar 
striule, which concentrically traverse the shell, are chiefly 
manifest. 

The auricles are rather large, very nearly equal, sub- 
rectangular, convex in the ventricose valve, concave in 
the flat one: in addition to their concentric lamellar 
striule they are merely radiated with fine unarmed cos- 
telle or coarse elevated striz. The auricular sinus is - 
nearly obsolete. The hinge-margin is almost level, but 
rises slightly on either side of the beaks in the upper 
valve; it is equal in the young to two-thirds the breadth 
of the shell, and even in the adult is more than equal to 
half the length, which latter is considerably superior to 
the breadth of the valves. 

The prevailing tint of the flatter valve is rufous, with 
some small angular markings of a darker hue upon the 
ribs; the umbo is of a yellowish white, or pale orange. 
The convex valve is almost white; sometimes too, to- 
wards the umbo, of a roseate flesh-colour, marbled with 
flexuous linear veins of white, and cinctured with two 

VOL. Il. Qa 


298 OSTREADE. 


fillets of dark red angular markings. In the young, this 
valve is usually orange, pink, or flesh-coloured, not un- 
frequently, likewise, lineated or variegated with white. 
The interior of both valves is generally pale, and _bor- 
dered with reddish chocolate colour. 

Six inches in length, and five in breadth, is about 
the average size of full-grown examples. 

The pendant borders of the mantle in the animal of 
maximus are variously marbled and mottled with brown, 
black, and white. Their fixed edges are fringed with a 
triple row of rather long filaments, which are lineated 
above with brown; one of the rows is less thickly set 
and longer than the rest; similar but rather shorter 
cirrhi fringe the free edges. The ocelli are of a greenish 
blue or purplish hue. The branchie are of an orange 
fawn colour. The body is pinkish white above, bright 
red or pink in its free portion. 

This fine species, though generally distributed through 
our seas, is only locally abundant, and cannot be said to be 
ever truly gregarious. It has a range of from three to 
forty fathoms, occurring most frequently in from fifteen to 
twenty-five fathoms, and most abundantly on the banks of 
Pecten opercularis. It appears to be most scarce on the 
east coast of England. Mr. Bean states that he has taken 
only three alive during very many years at Scarborough. 
It is much sought after for food, and is a constant visitant 
of the London markets. Scalloped with bread crumbs in 
its own shell, or fried with a little vinegar and pepper, it 
forms a very delicious morsel; it has the sweet flavour 
which characterizes all the scallops. The deep valves of 
the shell are much used to contain scalloped oysters, and, in 
fishermen’s huts, for rude but useful lamps. It ranges all 
along the Atlantic shores of Europe from Norway (Loven) 


PECTEN. 299 


to Gibraltar (M‘Andrew). As a fossil it occurs, though 
rarely, in the northern drift. 


P. opercutaris, Linneus. 


Subequivalve, suborbicular, rather strong, rarely speckled ; folds 
about twenty ; surface minutely radiated with closely disposed 
rows of scales ; ears nearly equal. 


Blate i, figs 3.3) Wie 55165) Ll ted 


List. Historia Conch. pl. 190, 191.— Knorr, Délices des 


Yeux, pt. v. pl. 28, f. 4. 


Ostrea opercularis, Linn. Syst. Nat. p. 1147.—PuLTeney, Hutchins, Hist. Dor- 


set, p. 36. — Maron and Rack. Linn. Trans. vol. viii. p. 
98; Dorset Catalog. p. 38, pl. 9, f. 1, 2, 4, 5.— Turr. 
Conch. Diction. p. 129, f. 74.—Born, Testacea Mus. Ces. 
Vind. p. 106.—Scurérer, Hinleit. Conch. vol. iii. p. 317, 
pl. 9, f. 3. — GME, Syst. Nat. p. 38325. — Ditiw. Re- 
cent Shells, vol. i. p. 266.— Index Testaceolog. pl. 10, 
f. 43. 


subrufa, PENN. Brit. Zool. ed. 4, vol. iy. p. 100, pl. 60, f. 63. — Donov. 
Brit. Shells, vol. i, pl. 12. 

Pecten pictus, DA Costa, Brit. Conch. p. 144, pl. 9, f.1, 2, 4, 5. 

lineatus, DA Costa, Brit. Conch. p. 147, pl. 10, f. 8.—Monr. Test. Brit. 
pp- 147, 579.—FLemine, Brit. Anim. p. 383. — Lam. Anim. 
s. Vert. (ed. Desh.) vol. vi. p. 143. 

opercularis, CHEMN. Conch. Cab. vol. vii. p. 341, pl. 67, f. 646.—Monv. 


Test. Brit. p. 145.—Turv. Dithyra Brit. p. 209.—FLEM- 
ING, Brit. Anim. p. 883.— Maceiiiiy. Moll. Aberd. p. 
224. — Brit. Marine Conch. p. 115.— Brown, Illust. 
Conch. G. B. p. 71, pl, 24, f. 1.— Axpsr, Catal. Moll. 
Northumb. and Durh. p. 76. — Lam. Anim. s. Vert. (ed. 
Desh.) vol. vi. p. 142.—Purirri, Moll. Sicil. vol. i. p. 82, 
and vol, ii. p. 57. — Sowersy, Thesaur. Conch. vol. i. p. 
53, pl. 17, f. 141 to 146.—H ant. Recent Shells, yol. i. p. 
272, pl. 10, f. 43.—CueEnu, Illust. Conch. Pecten, pl. 29. 
—Cuvier, Régne Anim. (ed. Croch.) pl. 75, f. 3. 


Ostrea sanguinea, Pout, Test. Sicil. vol. ii. pl. 28, f. 7, 8. 

lineata, PuLTENEY, Hutchins, Hist. Dorset, p. 36.—Donoy. Brit. Shells, 
vol. iy. pl. ]16.— Maron and Rack, Linn, Trans. vol. viii. p. 
99; Rack. Dorset Catalog. p. 38, pl. 10, f. 8.—Ditiw. Recent 
Shells, vol. i. p. 267.—Index Testaceolog. pl. 10, f. 44. 

Peclen sanguineus, Costa, Test. Sicil. p. 50. 


300 OSTREADA. 


Pecten subrufus, Turt. Dithyra Brit. p. 210, pl. 17, £. 1.— Brit. Marine Conch. 
p- 116. — Sowersy, Thesaur. Conch. vol. i. p. 53, pl. 19, f. 
208, 209, 210. 
», Audouinii, PAyRAUDEAU, Cat. Moll. Corse, p. 77, pl. 2, f. 8, 9.—HANL. 
Recent Shells, vol. i. p. 273. 
Peigne operculaire, CHENU, Traité Element. p. 101, f. 339. 
Pecten plebeius and Pecten sulcatus (fossil), SowERBY, Min. Conch. pl. 393. 


Both valves of this orbicular shell are convex, but the 
lower one is decidedly the more so. They are tolerably 
strong, and similar in sculpture to each other, being every- 
where rough with minute scales or squamular crene, 
which are most crowdedly arranged on very numerous and 
closely disposed elevated radiating striule. From eighteen 
to twenty-three ribs diverge from the umbo of each valve ; 
these are but moderately elevated, and in the more typical 
examples rounded, and of about the same width as their 
interstices. In the variety Audowinii, the scales are espe- 
cially developed, and those which, crowning the summit 
of each rib, are seated on stria so coarse as almost to 
carinate it, are manifestly larger than the rest. The ribs 
of the immature specimens are abrupt, and narrower in 
proportion than in the adult: their interstices are simply 
sculptured with very delicate concentric lamelle. The 
auricles are of very nearly equal dimensions, and rather 
small than otherwise; they are subrectangular above, the 
under ones inclining slightly to the obtuse, the front one 
of the upper valve to the acute: occasionally they are 
costellated and echinated, but chiefly on the under valve, 
more frequently they merely exhibit coarse and minutely 
squamular elevated strie. The auricular sinus is small and 
shallow, delicately pectinated, or rather, minutely dentated 
(at times obscurely) below, with the terminal angulation 
smgle and acute. The hinge-margin is not level, but rises 
a little on either side of the beaks, particularly in the less 


PECTEN. 301 


convex valve, where it laps over, and is not unfrequently 
crowned with fine dentated scales; its entire length is 
scarcely equal to one half the distance from the beaks to 
the opposite ventral margin, which latter is strongly ar- 
cuated, the most projecting portion of the lateral curva- 
tures of the shell being (in the adult) rather above than 
below the middle of the sides. The triangular callus on 
either side of the cartilage in the under valve is large and 
rather projecting. The colouring is very variable, it is fre- 
quently of an uniform white, yellow, orange, red, brown, 
or purplish pink; with the under valve of a lighter 
east, and the interior whitish and more or less stained 
with the external painting. Often, too, it is clouded or 
variegated with two of these tints, as, for instance, with 
undulating streaks of white on a dark pinkish red ground. 
One of the most striking styles of painting is that ex- 
hibited in the variety lincatus, where the snowy surface 
of the valves is relieved in one or both of them by a dark 
red line crowning the summit of all the coste. A beau- 
tifully painted shell in our cabinet is speckled with snow- 
white spots, edged below with chocolate-red on a ground 
of crimson, with three of its ribs stained with brilliant 
orange yellow. The diameter ascribed to the species by 
the accurate Montagu, is ‘‘ about two inches and a half ;” 
but this is rather above than below the ordinary standard. 
The length very slightly exceeds the breadth, except 
in the young, where the converse prevails. The variety 
Audowinii is by no means uncommon, and is usually mottled 
or variegated, and of a darker colour internally than in the 
typical form. We met with a young single valve of it 
at Torquay, which, from the magnitude of its upper costal 
squamee, and the imperfect developement of its subsidiary and 
interstitial scales, presented the aspect of a distinct species. 


302 OSTREADA. 


) 


** Professor Macgillivray,” writes Mr. Jeffreys, ‘‘ showed 
me, this last summer, a shell, which, he said, had been named 
after himself (P. Macgillivrai, Edmonston, Ann. Nat. Hist. 
vol. xv. p. 250) ; it was undoubtedly an opercularis, having 
its outer coat eroded either by disease or some acid.” 

The animal is shaped like the shell. The margins of 
the mantle are freely open; both the fixed and free edges 
of the pendant borders are fringed with filaments of un- 
equal length, and appearmg as if arranged in two or three 
irregular rows. These are usually white; among the 
series nearest the shell are ranged at regular distances 
more than thirty bright pearly blue globular ocelli. The 
mantle-margins themselves are most usually variegated 
with brown. The body is large, the upper portion cream 
colour, and the lower or pointed and free part of a bright 
pink or vermilion hue. The foot is small, conical, and 
furnished with a byssal groove, from which young spe- 
cimens often spin a byssus and fix themselves to sea- 
weeds and corallines. The branchize are brownish or 
reddish. 

This handsome shell is generally distributed around our 
coast, living im various depths, from five to one hundred 
fathoms, but abounding most in from fifteen to twenty- 
five fathoms. It is often found gregariously associated in 
banks of considerable extent, and is abundant on most 
natural oyster-beds. It is the common scallop of the 
people, and besides being prized in many places as a de- 
licious article of food, whether fresh or pickled, its shells 
are turned to account in the making of ornamental work. 
It is generally distributed throughout the European seas, 
and is found fossil in the later tertiaries. 


Note.—Our valued friend and correspondent, Dr. Knapp, has paid particular 
attention to the variations of the different British species of Pecten. He finds, 


PECTEN. 303 


in the Frith of Forth, six varieties of the Pecten opercularis, according as the 
prevailing colour is brown, purple, yellow, or white variegated with blotches or 
undulated markings of some colour different from the general hue ; rarely does it 
occur of a pure white. Pecten varius, from the west coast, varies in like manner, 
and among its colours presents a pale-slate variety, with white markings. 
Pecten sinuosus presents similar changes, but has not been observed pale purple, 
and is rarely pure white. He distinguishes no fewer than eighteen colour- 
varieties of Pecten obsoletus, seven of which are white, four either pure or 
variously marked with purple, brown, and yellow; seven, purple, either plain or 
variously marked with white, yellow, and brown ; three, orange, or orange and 
white ; and one in which all the colours are equally mingled. 


P. Istanpicus, Miiller. 


Free, not marbled, set with from fifty to a hundred small but 
distinct ribs, which are not prickly, but armed with erect and 
peculiarly crowded vaulted scales. 


Lister, Hist. Conch. pl. 1057, f. 4.—SrpBa, Mus. vol. iii. pl. 
(G86 Lc 
Pecten Islandicus, MisuuER, Zool. Danic. Prodr. (1776), p. 248, No. 2990. — 
Tort. Dithyra Brit. p. 216. — Fiemine, Brit. Animals, p. 
385. — Macaittiv. Moll. Aberd. p. 226.— Brit. Marine 
Conch. p. 119.—Brown, Illust. Conch. G. B. p. 72, pl. 24, 
f. 3. — O. Fapric. Fauna Groenland. p. 415.— CHEMN. 
Conch. Cab. vol. vii. pl. 65, f. 615, 616.— Lam. Anim. s. 
Vert. (ed. Desh.) vol. vii. p. 145. — Say, American Conch. 
pl. 56, f. 1. — Sowrrpy, Thesaur. Conch. vol, i. p. 75, pl. 
17, f. 159, 160, 165. — Goutp, Invert. Massach. p. 134, f. 
87.—HANL. Recent Shells, yol. i. p. 284. 
Ostrea cinnabarina, Born, Index Mus. Ces. (1778) p. 87; Mus. Ces. Vind. p. 
103.—Ditiw. Recent Shells, vol. i. p. 256. 
os Islandica, GMELIN, Syst. Nature, p. 3326. — Turr. Conch. Diction. p. 
258.—Index Testaceolog. pl. 10, f. 21. 
Pecten Pealii, ConrAD, American Marine Conch. p. 12, pl. 2, f. 2. 
Encyclopédie Méthodique, Vers, pl. 212, f. 1. 


Notwithstanding that of the many supposed British 
individuals of this fine shell we have never seen a single 
individual which did not exhibit a fossilized appearance, 
we have preferred classing the P. Jslandicus among our 


304 OSTREADA. 


doubtful natives, rather than entirely excluding a species, 
the comparative nearness of whose ascertained localities 
fairly argues the possibility of its being at some time 
(if not already) discovered as a living inhabitant of our 
own waters. The following brief description has chiefly 
been drawn up from Newfoundland specimens. 

Suborbicular or broadly obovate, subequivalve tolerably 
strong or solid, not transparent, not polished, valves mode- 
rately convex, the upper one passing from light orange or 
livid flesh colour to reddish brown, often adorned with 
about three obscure paler rays, the colourmg matter dis- 
posed in lighter and darker concentric zones; the lower 
valve almost white, and decidedly the more shallow. 
Entire external surface radiated with crowded (from fifty 
to one hundred) irregularly disposed unequal costellar strize 
so grouped as to form numerous indistinct and unequal 
folds, which appear better defined when viewed from the 
interior. These linear ridges, which exist likewise upon 
the auricles, where, however, they become coarser, and 
occasionally less approximate, are roughened, but not 
aculeated, by an infinite number of minute and peculiarly 
close-set erect and vaulted scales. Hinge-margin more 
than equal to half the length of the shell. Auricles well 
defined: the front one very large, its upper corner nearly 
rectangular, its costelle few and large upon the lower 
valve; hinder auricle moderate in size, only half as 
long as the front one, but of similar depth; its angle 
not very obtuse. Angle of the auricular sinus, which 
is moderately profound, single, and acute. Internal sur- 
face white, polished, often a little pearly, sometimes with 
a subumbonal stain of dull red in the more convex valve; 
margin jagged by the external costellz. 

Our largest specimen, which measures four inches in 
breadth, is not above a third of an inch inferior in its 
length; the young shells are much less orbicular, an 
example an inch long exceeding this measurement in 
breadth by two-fifths of an inch. 

Although both Miller and Born are prior in point of 


PECTEN. 305 


date to Fabricius, the merit of first describing this shell 
adequately belongs assuredly to the latter; indeed the 
diagnoses in the ‘“‘ Prodromus” are far too brief to enable 
us to distinguish the species mentioned from their allied 
exotic congeners, however sufficient for the discrimination 
of them from those which inhabit the same shores. 

Pecten islandicus is an abundant fossil in the pleistocene 
beds of the Clyde, and may be found in numbers at low 
water in the Kyles of Bute, as observed by Mr. Smith 
of Jordanhill. It has been dredged always as dead valves 
and as if fossil in various depths of water, as off Skye in 
forty fathoms, near Mull in ninety fathoms, and off Zetland 
in one hundred fathoms (M‘Andrew). Also in thirty- 
five fathoms off Aberdeen (Thomas) where, Professor Mac- 
gillivray states, dead valves are common. It is a living 
inhabitant of the Norwegian, Greenland, and Boreal Ame- 
rican Seas. 


SPURIOUS. 


P. Jacopxus, Linneus. 


Ostrea Jacobea, Linn. (not Turt. Conch. Diction.) Syst. Nat. ed. 12, p. 1144; 
Mus. Ulric. p. 522.—Putrenry, Hutchins, Hist. Dorset, p. 
36.— Donovan, Brit. Shells, vol. iv. pl. 137.— Maron and, 
Rack. Linn. Trans. vol. viii. p. 97.—Rack. Dorset Catalog. 
p 37, pl. 13, f. 2.— Born, Mus. Ces. Vind. p. 98.—Pott, 
Test. Sicil. vol. ii. p. 149, pl. 27.— Ditiw. Recent Shells, 

t vol. i. p. 248. 

Pecten Jacobeus, PENN. (not Fleming), Brit. Zool. ed. 4, vol. iv. p. 100, pl. 60, 
f, 62,—Da Cosra, Brit. Conch. p. 143. —— Monr. Test. Brit. 
p. 144.—Turv. Dithyra Brit. p. 207.—Browy, IIlust. Conch. 
G. B. p. 71, pl. 24, f. 5. — Lam. Anim. s. Vert. (ed. Desh.) 
vol. vi. p. 130.—Puitipri, Moll. Sicil. vol. i. p. 78, and vol. 
ii. p. 56.—Sowersy, Thesaur. Conch. vol. i. p. 46, pl. 15, f. 
107, 108, and pl. 17, f. 153.—Hanuery, Recent Shells, vol. 
i. p. 269.—Cuviser, Régne Anim. (ed. Croch.) pl. 75, f. 2. 

» Jacobi, CHEMN. Conch. Cab. vol. vii. p. 273, pl. 60, f. 588. 
Encyclop. Méthodique, Vers. pl. 209, f. 2. 


VOL. II. RR 


306 OSTREAD A. 


A Mediterranean shell ; introduced by Pennant as “a rare 
shell in Great Britain,’ and said by Pulteney to have been found 
on the Dorset coast. As no specimens have been obtained of late, 
although never was the dredge so actively employed as during the 
last few years, it is to be presumed that this shell was included as 
British from that spirit of easy credulity which tempted our older 
writers to admit as indigenous so many exotic shells into their 
works, on the careless authority of their friends’ mixed collections, 
and imperfect memorres. 


OSTREA. Linnzwus. 


Shell variously shaped, inequivalve, more or less in- 
equilateral, often thick and irregular, upper valve most 
frequently flat or concave, under one convex, surface 
foliated, or with radiating furrows; hinge without teeth ; 
ligament lodged in a pit in each valve, the beak behind 
that of the under valve often produced and exhibiting a 
furrowed ligamental area. Muscular scar subcentral, pal- 
lial impression obscure, entire. 

Animal shaped like the shell, its mantle freely open 
and without tubes, the edges double, and each bordered 
by short tentacular fringes; no conspicuous ocelli; bran- 
chial leaflets not doubled on themselves ; labial appendages 
triangular, connected around the mouth by a plain mem- 
brane ; foot obsolete. 

The sexes of oysters, according to recent observations 
of Quatrefages, are distinct. Our most valued bivalve 
belongs to this genus, and is the only species of it now 
inhabiting our seas. During ancient epochs, as we learn 
from the fossils of both tertiary and secondary strata, 
many more kinds of oyster lived within our area, and 
multiplied so as to rival the contents of any modern 


oyster-beds. The discoveries of geologists open scenes of 


OSTREA. 307 


regret to the enthusiastic oyster-eater, who can hardly 
gaze upon the abundantly entombed remains of the ap- 
parently well-fed and elegantly shaped oysters of our 
Eocene formation, without chasing “a pearly tear away” 
whilst he calls to mind how all those delicate beings 
came into the world and vanished, to so little purpose. 


O. epuuis, Linneus. 


Plate LIV. and (animal) plate T. fig. 1. 


LisrEr, Anim. Angl, pl. 4, f. 26; Hist. Conch. pl. 193, 194. 

Ostrea edulis, Linn, Syst. Nat. ed. 12, p. 1148; Fauna Suecica, p. 520.—PENN. 
Brit. Zool. ed. 4, vol. iv. p. 102.— PutrENnry, Hutchins, Hist. 
Dorset, p. 36.—Monr. Test. Brit. p. 151.—Maron and Rack. 
Trans. Linn. Soc. p. 101.—Dorset Catalog. p. 38, pl. 11, f. 6.— 
Turt. Conch. Diction. p. 133; Dithyra Brit. p. 204. — FLem- 
ING, Brit. Animals, p. 392. — Brit. Marine Conch. p. 120.— 
Brown, fllust. Conch. G. B. p. 71, pl. 23, f 19, and pl. 30, f. 
6, 7.—Born, Mus. Ces. Vind. p. 113.—Dintw. Recent Shells, 
vol. 1, p. 280.—Index Testaceolog. pl. 10, f. 74.—Lam. Anim. 
s. Vert. (ed. Desh.) vol. vii. p. 217. — BiainvitiE, Manuel 
Malacolog. pl. 60, f. 1.—Croucu, Introd. Lam. Conch. pl. 12, 
f, 8. — Sowrrby, Genera Shells, Ostrea, f. 1.— Brown, Conch. 
Text-book (ed. 1), p. 111.-— Rrnve, Conch. Systemat. pl. 120, 
foole 

Ostreum vulgare, Da Costa, Brit. Conch. p. 154, pl. 11, f. 6. 

Ostrea hippopus, LAM. Anim. s. Vert, (ed. Desh.) vol. vii. p. 219. 

5  deformis, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 229. 

» parasitica, TuRT. (not Gmelin) Conch, Diction. p. 134, f. 81; Dithyra 
Brit. p. 204, pl. 17, f. 6, 7.— FLemine, Brit. Animals, p. 
3893.—Brit. Marine Conch, p. 120, f. 108.—Brown, LIllust. 
Conch. G. B. p. 71. 


There is as much dissimilarity of aspect between the 
sleek-looking valves of the flattened ‘‘ Native Oyster” of 
our markets, and the more coarse and rugged (but far 
more beautifully sculptured and coloured) solitary indi- 
viduals which are ordinarily termed ‘“ Rock Oysters,” as 
there exists in the acknowledged flavour of their several 
inhabitants. The former is too well known to require any 


308 OSTREADA. 


particular description, the latter is a much more character- 
istic looking shell and not very frequently observable, in 
fine preservation, in the cabinets of our collectors. Whilst 
those individuals most ordinarily met with at our tables 
have the surface of the upper valve of an uniform drab or 
brownish buff-colour, this variety is beautifully radiated, 
in addition, with lines and streaks of dull purplish crim- 
son or reddish chocolate colour, and its concentric la- 
melle, which are extremely thin, and usually composed 
of rather large plates, instead of bemg appressed, are more 
or less elevated, broadly overlap each other, and are rather 
obscurely folded in radiating fashion. The ribs, or rather 
radiating folds, of the lower valve, which are more or 
less numerous, and for the most part narrow or but mo- 
derately broad, are sometimes stained with rich purplish 
red towards the margin, and, when the concentric lamine 
are elevated (which is generally the case when the valve 
is attached by the apex alone), are wont to be sur- 
mounted by vaulted, and even occasionally somewhat tu- 
bular fimbriations. When this form is affixed by the 
entire surface of the lower valve, (which consequently loses 
all traces of colouring or sculpture), the lamine of the 
upper valve are quite devoid of folds, and the lower series 
of them overlaps, as it were, the ventral edge of the 
inferior valve. In ordinary circumstances, these lamine, 
when perfect, extend as far as the extreme edge of the 
attached valve, but the somewhat pearly substance of the 
interior, which is white (in one variety with purple stains), 
is never so far produced as the nacre of the other valve. 
The natural form of our undisturbed oyster, which is apt 
to vary greatly in that respect, but is, we believe, always 
broader than long, appears. to be obovate, contracted 
above, and dilated below; we have seen it, however, of 


OSTREA. 309 


almost as produced a shape as that of Virginia. The upper 
valve is always the flatter (or, at least, the more shallow), 
the lower the-more solid. The edges of the shell, although 
irregularly wavy, are never plicated, and are neither cre- 
nated nor scabrous, but the vicinity of the cartilage is often 
beset in one or both valves with closely-disposed raised 
denticular wrinkles (not granules) or even elevated rugose 
sulci, which run parallel to the hinge-line. These denticles 
vary very greatly in number and distinctness, sometimes 
becoming nearly if not quite obsolete. 

About four inches may be considered the average 
breadth for the full-sized common rough oysters of our 
markets, but they are occasionally found at least five 
inches wide. 

The animal of our oyster is much compressed, yet 
rather thick, and of a general drab colour, with darker 
viscera, and brownish margins to its mantle. The latter, 
except on the beaks, is freely open, with slightly pendent 
margins, double fringed, the filaments short and rather 
irregular; the anal orifice is sessile. The great adductor 
muscle is very powerful, white and round ; it is esteemed 
one of the sweetest morsels of the oyster’s body. The 
liver is of a greenish hue, and the ventral mass of a 
creamy white. 

The Ostrea edulis may be said to have its capital in 
Britain, for though found elsewhere on the coasts of 
Kurope, both northwards and southwards, in no part 
of them does it attain such perfection as in our seas, 
through which it is generally distributed, sparingly in 
some places, abundantly and in gregarious assemblages in 
others, chiefly inhabiting the laminarian and coralline zones. 
The ancient Romans valued our native oysters even as we 
do now, and must have held them in higher estimation 


310 OSTREADA. 


than those of Italian shores, or they would not have 
brought them from so far for their luxurious feasts. 
Juvenal records the exquisite taste of the epicure ;— 
Who 
At the first bite each oyster’s birth-place knew ; 


Whether a Lucrine or Circzean he ’d bitten, 
Or one from Rutupinian deeps in Britain. * 


In Bishop Sprat’s ‘‘ History of the Royal Society,” is 
contained the first paper of importance on the oyster- 
fisheries of England. It is selected by the bishop as 
one of the examples which he gives of the various 
kinds of papers read before the Royal Society at that 
time, and respecting it he well remarks, “it may, per- 
haps, seem a subject too mean to be particularly alleged ; 
but to me it appears worthy to be produced. For though 
the British oysters have been famous in the world ever 
since this island was discovered, yet the skill how to 
order them aright has been so little considered amongst 
ourselves, that we see at this day, it is confined to some 
narrow creeks of one single county.” The paper is so 
short, concise, and important in its bearing on the his- 
tory of British oyster-fisheries, that we transcribe it 
nearly entire. It is entitled, “ The History of the Ge- 
neration and Ordering of Green Oysters, commonly called 
Colchester Oysters,” and runs thus:—‘ In the month of 
May the oysters cast their spawn (which the dredgers 
call their spat); it is hke to a drop of candle, and 
about the bigness of an halfpenny. The spat cleaves 
to stones, old oyster-shells, pieces of wood, and such 


- “ Circeeis nata forent, an 
Lucrinum ad saxum, Rutupinoye edita fundo 
Ostrea, callebat primo deprendere morsu.” 
JUVENAL, Sat. iy. 140. 


OSTREA. Sit 


like things at the bottom of the sea, which they call 
cultch. It is probably conjectured that the spat in 
twenty-four hours begins to have a shell. In the month 
of May, the dredgers (by the law of the Admiralty 
Court) have liberty to catch all manner of oysters of 
what size soever. When they have taken them, with 
a knife they gently raise the small brood from the cultch, 
and then they throw the cultch in again, to preserve 
the ground for the future, unless they be so newly 
spat that they cannot be safely severed from the cultch ; 
in that case they are permitted to take the stone or 
shell, &c. that the spat is upon, one shell having many 
times twenty spats. After the month of May it is 
felony to carry away the cultch and punishable to take 
any other oysters, unless it be those of size (that is to 
say) about the bigness of an half-crown piece, or when 
the two shells being shut, a fair shilling will rattle 
between them. The places where these oysters are chiefly 
catched are called the Pont-Burnham, Malden, and Colne- 


“ 


waters. * * * This brood, and other oysters, they carry 
to creeks of the sea at Brickel-sea, Mersey, Langro, 
Fringrego, Wivenho, Tolesbury, and Saltcoase, and there 
throw them into the channel, which they call their beds 
or layers where they grow and fatten, and in two or 
three years the smallest brood will be oysters of the 
size aforesaid. Those oysters which they would have 
green, they put into pits about three foot deep, in the 
salt-marshes, which are overflowed only at spring-tides 
to which they have sluices, and let out the sea-water 
until it is about a foot and half deep. These pits from 
some quality in the soil co-operating with the heat of 
the sun, will become green and communicate their colour 
to the oysters that are put into them in four or five 


312 OSTREADA. 


days, though they commonly let them continue there 
six weeks or two months, i which time they will be 
of a dark green. * * * The oysters when the tide 
comes in lie with their hollow-shell downwards, and 
when it goes out they turn on the other side; they 
remove not from their places unless in cold weather to 
cover themselves in the oose. The reason of the scarcity 
of oysters, and, consequently, of their dearness, is because 
they are of late years bought up by the Dutch. There 
are great penalties by the Admiralty Court laid upon 
those that fish out of those grounds which the court 
appoints, or that destroy the cultch, or that take any 
oysters that are not of size, or that do not tread under 
their feet, or throw upon the shore, a fish which they 
eall a five-finger, resembling a spur-rowel, because that 
fish gets into the oysters when they gape and sucks 
them out. * * * The oysters are sick after they have 
their spat; but in June and July they begin to mend, 
and in August are perfectly well. The male oyster is 
black-sick having a black substance in the fin; the female 
white-sick having a milky substance in the fin. They 
are salt in the pits, salter in the layers, saltest at sea.” 
From this old paper the greater part of the matter 
contained in articles on the subject of oyster-fisheries in 
the several Encyclopedias has been derived. In the 
earlier volumes of the ‘ Philosophical Transactions,” are 
several notices on the subject of oysters, especially a short 
account of the spat by the celebrated Leewenhoeck, and 
a letter from the Rey. Mr. Rowland to Dr. Derham, in 
which it is stated that though the beds in the Manai 
furnished then (1720) as they do now, abundant oysters, 
twenty-four years previously none existed in the locality ; 
they were originally laid down there by a private gentle- 


OSTREA. 313 


man. These beds are now recruited from the Irish 
coast. 

In order to obtain the most recent information respect- 
ing the oyster-beds which supply the London market, the 
extent of the supply, and the opinions of those practi- 
cally concerned in their management, and in the sale of 
their products, on points in the history and value of 
what may be termed cultivated oysters, we drew up a 
series of queries, to which, chiefly through the obliging 
interest taken in the inquiry by Mr. J. S. Sweeting, of 
159, Cheapside, we have received from that gentleman,* 
and from other well-informed quarters, very full replies, 
the results of which we now give in a condensed form. 

The oyster-beds from which the principal supply for 
the London market is procured, are those of Whitstable, 
Rochester, Milton, Colchester, Burnham, Faversham, and 
Queenborough, all artificial beds, furnishing natives. Since 
the introduction of steamboats and railroads, considerable 
quantities of sea-oysters are brought from Falmouth and 
Helford in Cornwall, from the coast of Wales, the Isle of 
Wight, and neighbourhood of Sussex, and even from Ire- 
land and Scotland, after the winter sets in, as before they 
would not keep fresh enough when brought from long dis- 
tances. The supply derived from natural beds varies 
much, since on some of them the oysters are not sufficiently 
abundant to pay for dredging. The sea-oyster is often 
before being brought to market kept for a time im arti- 
ficial beds in order to improve its flavour. 

The most esteemed oysters are those of the small, ovate, 
but deep-shelled variety, called natives, among which those 
of the river Crouch, or Burnham oysters, are pre-eminent 

* We haye to return many thanks to Mr. James Wickenden of Rochester, 
and Mr. W. H. Williamson, senior, of the same town, for very full information. 


VOL. II, ss 


314 OSTREADA. 


for their marine flavour; probably on account of the faci- 
lities for rapid importation of them in fine condition. 
Much of the quality depends on the ground and condition 
of the beds; and oysters of different years from the same 
place often vary materially in this respect. They are con- 
sidered full-grown for the market when from five to seven 
years old: sea-oysters at four years. The age is shown 
by the annual layers of growth or “shoots” on the 
convex valve. Up to three or four years, each annual 
growth is easily observed, but after their maturity it is 
not so easy to count the layers. Aged oysters become 
very thick in the shell. In the neighbourhood of fresh 
water the oyster grows fast, and improves in body and 
flavour. The flavour is said by some to improve by shift- 
ing the oysters as they approach their full growth. Frost 
kills numbers, and when they are left dry at low ebbs, the 
run of fresh water from the land turns them what is called 
“foxy,” of a brownish red colour. They are sometimes 
seized with sickness during the spawning season and con- 
siderable numbers may die. Much labour is required to 
keep the beds in good order, cleansed from shells and 
rubbish, star-fishes, barnacles, corallines, and sea-weed, 
which grow freely in the spring of the year. On the 
cleanliness of the ground, the prolific character of the 
bed, if the oysters breed there, depends. If carefully 
attended to, a bed may last any length of time, but if 
neglected it will become overgrown. with weed and buried 
in mud, so that it can only be reclaimed by restocking at 
a great expense, or is altogether destroyed. Artificial beds 
for the purpose of keeping a supply at hand for the 
London market are said to have been commenced about 
the year 1700 by the Kent and Essex Companies of 
Dredgers. The oyster does not breed freely, often not 


OSTREA. SLD 


at all, on artificial beds, so that they require to be 
constantly restocked; and when they do spawn under 
such circumstances, the fry are said seldom to come to 
perfection. On their natural grounds they spawn pro- 
fusely during the season, 7. ¢. during the summer months. 
The developing spawn is technically called “ spat.” 

The oyster has not a few enemies. Star-fishes, espe- 
cially the Uraster rubens and Solaster papposa, are sup- 
posed todo great injury to the beds; the dredgers call 
them five-fingers. Whelks, called by the fishermen whelk- 
tingle, or sting-winkle, are also said to do much damage, 
perforate the shells with small holes, selecting especially 
those of from one to two years’ growth. They are popularly 
supposed to strike directly for the heart of the oyster. That 
most curious sponge, the Cliona, perforates the shell in 
all directions, and directs its operations, with a won- 
derful symmetry as we now know through the curious 
investigations of Mr. Albany Hancock. Milne-Edwards 
states that in some places on the coast of France the 
oyster-beds run a risk of being destroyed through the 
tube-constructing powers of certain Annelides (hermella), 
becoming buried under masses of their curious habitations 
framed of agglutinated particles of sand. 

In London, the chief consumption of common oysters is 
from the 4th of August to January, and of natives from 
October to March. The consumption is said to be greatest 
during the hottest months after the commencement of the 
oyster-season ; the warmer the weather, the more oysters 
are consumed. They are brought to market in craft of 
various sizes; they are packed in bulk closely in the 
hold ; in some cases a cask of salt water is kept from 
which to sprinkle them superficially. Those that come 
by rail are packed with their convex shells downwards 


316 OSTREADA. 


in bags and barrels. From the boats they are transferred 
to the salesmen, who keep them in a little salt and spring 
water, and shift them every twelve hours. Some pre- 
tend to improve them by “ feeding” them with oatmeal. 
Oysters, like other bivalves, live chiefly on infusorie. 
The quantity consumed annually in London varies in 
different seasons. One informant states twenty thousand 
bushels of natives, one hundred thousand bushels of com- 
mon oysters to be about the mark; another estimates 
the quantity sold in the season from the 4th of August 
to the 12th of May to be nearly one hundred thousand 
London bushels, each bushel being three Manchester or 
imperial bushels; and that about thirty thousand bushels 
of natives are sold during the same period by various 
companies. During the season commencing on August the 
Ath, 1848, and ending May 12th, 1849, Mr. Wickenden 
estimates about one hundred and thirty thousand bushels 
of oysters to have been sold in London, though of that 
quantity about one-fourth was sent away to various parts 
of the United Kingdom and the Continent. 

The oyster-fisheries are protected by legislative enact- 
ments. Various acts of parliament have * been passed for 
the better preservation of the oyster-beds and prevention 
of trespass upon them, To steal oysters is a larceny; to 
dredge on an oyster-bed unlawfully or wilfully, is being 
guilty of a misdemeanour, punishable by fine or impri- 
sonment—fine not to exceed 20/., or imprisonment three 
calendar months. It is as well that ardent conchologists 
should know these (to them) obnoxious enactments, for 
otherwise they may find the search for a new or rare 
species at the wrong season of the year cost more trouble 


* 31 George III. c, 51.—48 George III. c. 144.—7 and 8 George IV. c, 29. 


OSTREA. Sa 


and expense than it is worth. It is not only artificial 
oyster-beds which are claimed as private property, but 
many of those in the open sea, on various parts of our 
coast. 

Oysters of good repute are fished in the neighbourhood 
of the Channel Islands. There are two oyster-banks, the 
one off Guernsey, and the other off Jersey. The former 
is of little importance; the latter of considerable value. 
They belong to the region of oyster-banks which extends 
along the coasts of Normandy and Brittany. Dr. Knapp 
informs us that the number procured annually from them 
for the use of the Channel Islands and English markets 
cannot be less than eight hundred thousand tubs, each tub 
containing two English bushels, and in some years thrice 
that quantity is believed to be procured from those banks 
during the season. As many as three hundred cutters 
have been employed upon them dredging. The oysters on 
the Jersey bank are of large size, and are sold at from five 
to seven shillings the tub, or from three to four pence 
the dozen. Milne-Edwards and Audouin state (in their 
‘“‘ Histoire Naturelle du Littoral de la France”) that 
during the year 1828 the total number dredged on the 
French banks of this region was about fifty-two million, 
the average price of which was three francs fifty cents for 
every “millier,” ¢.¢. twelve hundred. These French oyster- 
banks are stated by the authors quoted to yield a produce 
valued at from eight to nine hundred thousand frances a 
year. Before the French oyster-fisheries were put under 
restrictions the banks were deteriorating through continual 
fishing. 

The oyster-fishery of most consequence in Scotland is 
that of the Frith of Forth, respecting which some valuable 
information has been communicated to us by Dr. Knapp. 


318 OSTREADA. 


The oyster-beds there extend about twenty miles, from the 
Island of Mucra to Cockenzie, and are dredged in from 
four to six or seven fathoms water. The best are pro- 
cured near Burntisland, on a bed belonging to the Earl of 
Morton, on the rocky ground, opposite Portobello, and at 
Prestonpans. The price varies, wholesale, from two shillings 
to two shillings and sixpence the hundred, the retail price 
from two shillings and sixpence to four shillings and six- 
pence, or even five shillings. Hight or ten years ago the 
price was much less, but an individual having taken the 
ground off Newhaven for a high rent, which he is said 
never to have paid, so cleared the beds that they have 
since been comparatively rare. 

Mr. George Moffat, fishdealer in Edinburgh, has, at the 
request of Dr. Knapp, very kindly drawn up a note on the 
statistics of the oyster-fisheries of the Frith of Forth, and 
the consumption of oysters in the Edinburgh market, 
which, on account of its completeness, we print entire in a 
note.* 


* Note on the oyster-fisheries which supply the Edinburgh market, by Mr. George 
D. Moffit. 


Twenty-five boats, working for four months, viz., September, October, March, 
and April, say sixty-four days (four days per week), dredge at an average 480 
oysters per boat per day. Inde, 

25 x 64 x 480= : : : : : 768,000 


Eight boats, working for four months, viz., November, December, 
January, and February, say sixty-four days (four days per week), 
dredge at an average 480 oysters per day per boat. Inde, 
8 x 64 x 480= : - : : . 245,760 


Number of oysters dredged at an average in the season at Newhaven, 1,013,760 
*.* Fisherrow, Prestonpans, and Cockenzie, may be taken i ald at the 
same ratio. Therefore, doubling the above, makes 2,027,520 oysters, which 
may be calculated to be dredged in the Forth in the season ; only three-fourth 
parts of which, however, it is believed are sent to Edinburgh, being 1,520,640. 


OSTREA. 319 


Natural oyster-beds of small extent occur at some dis- 
tance from land in several places around the Isle of Man. 
The principal is that off Laxey ; but though the oysters are 
fine and well-flavoured, their abundance is not sufficient to 
induce a regular fishery. 

On both sides of Ireland oysters abound in many places, 
and some of the banks are valuable, producing oysters in 
abundance, and of good quality. In the west, the most 
famous are Burton Bindon’s oysters, which are highly 
esteemed in Dublin. They are the SBurran oysters, 
brought from the Burran bank in Galway bay, where 
they are laid down artificially, after having been originally 
dredged chiefly near Achil Head. There are oyster-beds 
in the Shannon, said, in 1836, to yield a revenue of 
1400/7. annually, and to employ seventy men and sixteen 
boats. Some small oyster-beds in Clare are private pro- 
perty, and yield various incomes, as do those also in 
Cork harbour, but none of them are of any extent. 
Oysters are dredged from natural beds on the coast of 


Again, 
From the foregoing average the quantity dredged per day may be stated as 


follows :— 
Boats. Oysters. 


Principal season, four months, 25 %< 480= - : 12,000 
Secondary season, four months, 8 x 480= . ‘ : 3,840 
Per day for Newhaven, 15,840 


The same number for Fisherrow, Prestonpans, and Cockenzie, makes 31,680, 
threefourth-parts of which, as before mentioned, come to Edinburgh, being 
23,760. 

With regard to the consumption in Edinburgh, it will be apparent, that out o¢ 
the season of eight months, only one hundred and twenty-eight days are stated, 
these being the men’s working-days. But the days of the consumption of these 
Mollusks in town are (excluding Sundays), out of the eight months, two hundred 
and seven days. Inde, as before, 

1,520,640 — 207 = 7346 oysters, being the average daily consumed in Edin- 
burgh during the season, from the beginning of September till the end of April. 


320 OSTREADA. 


Wexford, and elsewhere, in order to be laid down on 
the Beaumaris beds. The most renowned of the Irish 
oyster-fisheries is that of Carlingford. The shell-fish 
are there dredged by boats each manned by from three 
to five men, who take about fifty dozen a day. The 
oysters of each boat are deposited within a ring of large 
stones till sold; the place being marked by a buoy. 
They are sold to dealers only, at from 8d. to 2s. for ten 
dozen. A yearly fee of 5s. is paid by each boat to the 
Marquis of Anglesey. The fishermen earn from 4d. to 
Is. 6d. per diem, and are mostly landholders.* 

There are natural oyster-beds in Belfast bay, on banks 
at a depth of from twelve to twenty-five fathoms. Mr. W. 
Thompson informs us that in March 1848 he had the 
four largest oysters selected from about five hundred taken 
on these beds, and by weighing them before their being 
opened found two to be each one pound and a half, the 
third one pound and three-quarters, and the fourth two 
pounds, imperial weight. ‘The two largest oysters,” he 
states, “‘ on being taken from their shells weighed each an 
ounce and a half, and the others somewhat less. The 
oysters from which these were selected were sold at the 
rate of sixteen shillings for the one hundred and twenty- 
four. The shells were in length from five inches and a half 
to six and a half; in breadth from five inches to five and 
a half, and in depth with the valves closed two inches and 
a half.” There are oyster-beds partly private and in- 
creased by planting in Loch Swilly. Irish oyster-dredgers 
have a notion that the more the banks are dredged, the 
more the oysters breed. 


* Report on Irish Fisheries for 1836. 


OSTREA. Bow 


SPURIOUS. 


O. crista-cAaLu, Linnseus. 


Knorr, Délices des Yeux, pt. 5, pl. 16, f. 1. 

Mytilus crista-galli, Linn. Syst. Nat. ed. 12, p. 1155.— Maron and Rack. 
Trans. Linn. Soc. vol. viii. p. 104. — Turr. Conch. Dic- 
tion. p. 109.—Born, Mus. Cees. Vind. p. 120.—Diiiw. 
Recent Shells, vol. i. p. 300. 

Auris-porci, CHEMN. Conch. Cab. vol. viii. p. 52, pl. 75, f. 684. 

Ostrea crista-galli, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 234.—SowErsy, 

Genera Shells, Ostrea, f. 2. — Penny Cyclopzedia, vol. xvii. 
p. 363.—RezEvE, Conch. Systemat. pl. 121, f. 2.—Cuvier, 
Reégne Anim. (ed. Croch.) pl. 72, f. 3.—CuxEnu, Lecons 
Elém. Hist. N. p. 108, f. 358. 


An Asiatic shell ; introduced as taken alive on ships bottoms. 
Montagu, who first indicated it as British by name, scarcely ap- 
pears to have intended this species, since, in his description, he omits 
all mention of the characteristic granules of the exterior, and the 
scabrous edges of the interior. 


O. rrons, Linnzus. 


ARGENVILLE, Conch. pl. 23, f. D. 
Mytilus frons, Linn. Syst. Nat. ed. 12, p. 1155.— Born, Mus. Ces. Vind. p. 
123, vignette, b. at p. 121. — Burrows, Elements Conch. pl. 
10, f. 4.—Dititw. Recent Shells, vol. i. p. 301.—Index Tes- 
taceolog. pl. 12, Mytilus, f. 3. 
Ostrea frons, CHEMN. Conch. Cab. vol. viii. p. 61, pl. 75, f. 686. 
»  erista-galli, Monv. (not Lam.) Test. Brit. p. 160?—Turr. Dithyra Brit. 
p. 202. 
» rubella, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 231. — Cuvier, 
Régne Anim. (ed. Croch.) pl. 72, f. 2. 
»  Umacella and erucella, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 231. 
» folium, SowERBY, Genera Shells, Ostrea, f. 3— REEVE, Conch. Systemat. 
pl. 121, f. 3.—Sowersy, Conch. Manual, f. 181. 


A West Indian shell ; introduced by Dr. Turton, as it had been 
taken alive on the bottom of a foreign vessel. The specimen in his 
cabinet is not the true crista-galli as he imagined, but a character- 
astic example of the long lost frons of Linnaeus. 


VOL. II. TP 


a22 OSTREADE. 


ANOMIA. Linnzus. 


Shell oblong or suborbicular, usually more or less irregu- 
lar, inequivalve, surface of upper and convex valve smooth, 
or lamellar, or ornamented by radiating and scaly striz ; 
under-valve flattened, deeply emarginated near the beak 
on one side by a large and ovate or round sinus, through 
which passes a strong adductor attached to an opercular 
shelly mass, by which the animal and its shell is fixed to 
various substances. Beaks very small; no teeth; valves 
united by a short and thick cardinal ligament ; muscular 
impressions several. 

Animal shaped like the shell, mantle freely open, with 
pendant margins bearing a double fringe of short cirrhi. 
No conspicuous ocelli. No siphonal tubes. Body massive. 
Foot very small, often nearly obsolete. Adductor muscle 
divided into three portions, the longest passing through the 
notch in the lower valve, and attached to the opercular 
piece, partly attached to the inner surfaces of the shell. 
Branchial leaflets doubled on themselves. Mouth sur- 
rounded by membranous borders, and two pair of long 
labial tentacles, striated on both sides. Sexes distinct. 

Linneus included in his genus Anomia, the species of 
Terebratula. Misled by a false analogy, he considered 
these very different mollusks to be organized on the same 
plan, and the perforations of one of the valves in each to be 
of similar origin. Lamarck, in like manner, fancied that 
in Anomia he saw a passage into Terebratula and the 
Brachiopods ; and some anatomists even believed that they 
had discovered transitional characters. A close examina- 
tion shows that there is no relationship of affinity between 
them, but only a resemblance through formal analogy. 


ANOMIA. 320 


The parts which seem, at first glance, in each to be iden- 
tical, prove not to be homologous, upon investigation. 

Anomia has really very close relations with Pecten, and 
is connected to the latter by the curious genus Hemipecten of 
Reeve. The perforation in one of the valves of Anomia, 
is chiefly a greater extension of the auricular sinus in 
Pecten ; and when the very young fry of this genus shall 
have been carefully observed, we believe they will be found 
spinning a byssus which, passing through this sinus, fixes 
the shell in the first instance, before a portion of it be- 
coming attached, eventually becomes detached with a part 
of the adductor muscle, and forms the opercular process. 
The animal is deleterious, and has a peppery taste. 

The species of this genus are distributed through the 
seas of all regions, and fossil forms range far back in time, 
but never appear to have been very abundant. There is 
great difficulty in the determination of both recent and 
fossil forms. Opinion as to the true sources of specific 
character among the Anomice has fluctuated greatly ; some 
conchologists would limit the number of admitted forms to 
a very few; others would swell the specific list by num- 
bers of too evident varieties. 

In the following account of the British Anomia, we have 
adopted the views at present held by many of the most 
distinguished malacologists of this country and of the Con- 
tinent. We do so, however, only provisionally, and regret 
that the subdivisions here adopted are not borne out by 
an examination into the characters of the several animals, 
To this subject Mr. Clark has this year addressed his 
particular attention: the results of his researches go 
strongly against the notion of the specific permanency of 
characters in our native Anomia, and we feel bound to give 
the following extract from his communication relative to 


324 OSTREADA. 


the features of their shells, whilst under Anomia ephippium 
we present his observations on the animal, all resulting in 
inducing that eminent observer to hold to the specific 
unity of all our British forms :— 

‘With regard to the young, or dwarf 4. ephippium, 
the A. squamula, A. aculeata, and A. striolata, often 
crowded in groups of fifteen or twenty individuals on a 
single Pecten opercularis, I have not a doubt of their being 
mere varieties of A. ephippium; all these, often adopt the 
markings of the substances on which they are fixed, and as 
often show an entire disregard thereto, though they all 
more or less invariably maintain the only true distinctive 
character of the type, the decided squamose appearance, 
which is never lost, whatever other markings there may 
be. Ihave seen shells combining all the supposed distine- 
tive marks of each species or variety centred in one indi- 
vidual, in which the decided smooth glossy <A. sguamula 
commenced the umbonal part of the structure, gradually, 
for the middle region, gliding into the squamous A. 
ephippium, and dividing the basal portion, right and left, 
the one, into the spinous asperities of A. aculeata, the 
other, into the delicate smooth lines or striule of A. 
striolata. Nothing is more common than to see shells 
half squamula and half ephippium, half A. aculeata and 
half A. striolata, and other admixtures of the characters 
of two or three supposed species, on the same shell. These 
facts prove, that the various markings, ribs, strie, &c., do 
not always, as it were, by reflexion take the markings of 
the substances on which they are fixed. All the last four 
dwarf varieties of A. ephippium, are also found at the 
roots of Alge and Fuci, but they, like their brethren on 
shells, present, in the same individual, similar discrepancies 


of colour, and admixture of characters. 


ANOMIA. 325 


“The 4. cylindrica or A. cymbiformis, is A. ephippium, 
taking the hollowed out boat-like appearance, in conse- 
quence of clasping the cylindrical stalks of the Fwci. The 
A. tubularis is the same type, having the margins of the 
apertures elongated to suit its condition to some irregu- 
larity of the body on which it is fixed. The A. punctata 
is of the same character, viz. A. ephippium, deriving its 
papille-like markings from the substances on which it is 
placed. I do not know A. fornicata and A. coronata. 

““T have now noticed all the British varieties I am 
acquainted with, and there is certainly no sculpture on 
them of so decided a character as to pronounce specific 
distinction ; therefore all the markings, shapes, colours, of 
this Protean genus of varieties being inadequate for the 
foundation of species, we must have recourse to our sheet- 
anchor, the malacology of the animal, to assist our deter- 
minations, and after the examination of a great number of 
individuals, embracing nearly all the British species, we 
can arrive at no other conclusion than a firm conviction 
that they are all varieties.” 


A. epHippium, Linneus. 


Destitute of natural sculpture; no triangular cavity on the 
under valve beneath the hinge. 


Plate LV. fig. 2, 3, 5, 7, and (Animal) Plate T. fig. 2. 


Anomia ephippium, Linn. Syst. Nat. ed. 12, p. 1150.—Prnn. Brit. Zool. ed. 4, 
vol. iv. p. 109, pl. 62.—Donov. Brit. Shells, vol. i. pl. 26, 
middle fig. — Mont. Test. Brit. p. 155.— Maron and 
Rack, Trans. Linn. Soe. vol. viii. p. 102; Dorset Catalog. 
p. 38, pl. 11, f. 3.—Turv. Conch. Diction. p. 2.—Dithyra 
Brit. 227, pl. 18, f. 1, 2, 3, and pl. 17, f. 10. — Fiemine, 
Brit. Animals, p. 395.—Maceri1iv. Moll. Aberdeenshire, 
p- 230. — Brit. Marine Conch. p. 121. — Brown, Illust. 
Conch. G. B. p. 69, pl. 22, f. 1, 4. — Born, Mus. Ces. 
Vind, p. 117. -— Rerzius, Noy. Gen. p. 10. — CHEmn, 


326 


OSTREADA. 


Conch. Cab. vol. viii. p- 81, pl. 76, f. 692, 693. — Pott, 
Test. Sicilia, vol. ii. p. 186, pl. 30, f. 9, 10.—Ditiw. Re- 
cent Shells, vol. i. p. 287.—Index Testaceolog. pl. 11, f. 3. 
—lLam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 273. — 
Bownicu, Elements Conch. pt. 2, Bivalves, f. 90.—Mawe, 
Linn. Conchology, pl. 15, f. 6. —Sowxrsy, Genera Shells, 
Anomia.— Sow. (jun.) Concholog. Manual, f. 186.— 
Puivipri, Moll. Siciliz, vol. i. p. 92, and vol. ii. p. 65.— 
REEVE, Concholog. Systemat. pl. 124. 


Anomia electrica, Linn. Syst. Nat. ed. 12, p. 1150. —Turr. Conch. Diction. p. 


ty) 


2 


” 


1, f. 67; Dithyra Brit. p. 226, pl. 17, f. 8, 9. — FLEMine, 
Brit. Anim. p. 394.—Brit. Marine Conch. p. 120.—Brown, 
Illust. Conch. G. B. p. 70, pl. 46, f. 5.— Dmuw. Recent 
Shells, vol. i. p. 287.—Index Testaceolog. pl. 11, f. 5.—Lam. 
Anim. s. Vert. (ed. Desh.) vol. vii. p. 274. 


squamula, Linn. Syst. Nat. ed. 12, p.1150; Fauna Suecica, p, 521.— 


Penn. Brit. Zool. ed. 4, vol. iv. p. 109.—Da Costa, Brit. 
Conch. p. 167.—Putrenry, Hutchins, Hist. Dorset, p. 36. 
— Mont. Test. Brit. p. 156.— Maron and Rack. Trans. 
Linn. Soe. vol. viii. p. 102.—Dorset Catalog. p. 39, pl. 13, 
f. 4. —Turr. Conch. Diction. p. 3; Dithyra Brit. p. 229, 
pl. 18, f. 5, 6, 7.— FLEemine, Brit. Animals, p. 395.— 
Maceituiy. Moll. Aberd. p. 231.—Brit. Marine Conch. p. 
122. — Brown, I[lust. Conch. G. B. p. 69, pl. 22, f. 5. — 
CueEmn. Conch. Cab. vol. viii. p. 86, pl. 76, f. 696.— Pott, 
Test. Sicilia, vol. ii. p. 186, pl. 30, f. 18. — Lam. Anim. s. 
Vert. (ed. Desh.) vol. vii. p. 275. 


cepa, Linn. Syst. Nat. ed. 12, p. 1151. — Putrenzy, Hutchins, Hist. 
Dorset, p. 37.—Donov. Brit. Shells, vol. i. pl. 26, side fig.— 
Turt. Conch. Diction. p. 3; Dithyra Brit. p. 228, pl. 18, f. 4. 
— Fiemine, Brit. Animals, p. 395. — Brit. Marine Conch. p. 
121.— Brown, Illust. Conch. G. B. p. 70, pl. 39, f. 12%. — 
CuEmn. Conch. Cab. vol. viii. p. 85, pl. 76, £. 695. — Pott (as 
caepa), Test. Sicil. vol. ii. p. 182, pl. 30, f. 1, 2, 5 to 8.— 
Dittw. Recent Shells, vol. i. p. 287.—Lam. Anim. s. Vert. (ed. 
Desh.) vol. vii. p. 274. 

tunica cepe, Da Costa, Brit. Conch. p. 166, pl. 11, f. 3. 

punctata, CHEMN. Conch. Cab. vol. viii. p. 88, pl. 77, f. 698. — Tur. 


Dithyra Brit. p. 231, pl. 18, £. 11.—F Leming, Brit. Animals, 
p- 395. — Maceituiv. Moll. Aberd. p. 232. — Brit. Marine 
Conch. p. 122. — Brown, Illust. Conch. G. B. p. 70, pl. 39, 
f. 13*.— GMELIN, Syst. Nat. p. 3346.— Ditw. Recent 
Shells, vol. i. p. 288.—Index Testaceolog. pl. 11, f. 6. 


fleauosa, GMELIN, Syst. Nat. p. 3349 (from Schrot. Einleit. Conch. vol. 


iii. p. 418, pl. 9, f. 11).—Index Test. pl. 12, Anomia, f. 31. 


rugosa, GMELIN, Syst. Nat. p. 3349 (from Schrot. Einleit. Conch. vol. 


ili. p. 419, pl. 9, f. 12). 


ANOMIA. One 


Anomia cylindrica, GMELIN, Syst. Nat. p. 3349, from Schrét. Einleit. Conch. vol. 
ill. p. 419, pl. 9, f. 18. — Turr. Conch. Diction. p. 6; Di- 
thyra Brit. p. 232.—FLEmine, Brit. Anim. p. 395.—Mac- 
GILLIv. Moll. Aberd, p. 232.—Brit. Marine Conch. p. 123. 
— Brown, Illust. Conch. G. B. p. 70, pl. 22, f.7, 8.— 
Dittw. Recent Shells, vol. i, p. 291.—Index Testaceolog. 
pl. 1], £ 13. 

»  margaritacea, Pout, Test, Sicilia, vol. ii, pl. 30, f. 11.—Puizipri1, Moll. 
Sicil. vol. ii. p. 65. 
» cymbiformis, Matron and Rack. Trans. Linn. Soc. vol. viii. p. 104, pl. 3, 
f. 6.—Mont. Test. Brit. Suppl. p. 64. 
»  patellaris, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 273 (fide Des- 
hayes). 
>  pyriformis, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 275. — Potixz, 
Galerie Douai, vol. ii. p. 41, pl. 43, f. 10. 
»  fornicata, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 275 (probably ).— 
Turr. Dithyra Brit. p. 234, pl. 18, f. 12, 13. — FLEMING, 
Brit. Anim. p. 396.—Brit. Marine Conch. p. 123.—Brown, 
Illust. Conch. G. B. p. 70, pl. 39, f. 14*, 15*. 
>» tubularis, Tur. Dithyra Brit. p. 234, — FLemine, Brit. Anim. p. 396. 


—Brit. Marine Conch. p. 124.—Brown, IIlust. Conch. G. 
B. p. 70. 

»  coronata, BEAN, Mag. Nat. Hist. vol. viii. p. 564, f. 52. 

> polymorpha, PutiiPPt, Moll, Sicil. vol. ii. p. 65. 

»  scabrella, Puriiert, Moll. Sicil. vol. ii. p. 65, pl. 18, f. 1. 


Professor Macgillivray has justly remarked, in his work 
on the Molluscous Animals of Aberdeenshire, &c., that the 
“‘ property which the Anomie have of assuming and re- 
taining the impression of the foreign bodies to which they 
adhere, ought to render us very circumspect in defining 
species.” Acting under this impression, we have, in ac- 
cordance with the opinion of the majority of those British 
naturalists who enjoy the most ample opportunities for 
examining and comparing the Anomie in every stage of 
growth, in every circumstance of habitat, and from the 
most widely extended range of localities, united into one 
species, after close personal study of the valves and careful 
scrutiny of the synonymy, the various shells (both British 
and foreign) above enumerated. Of the varieties, some few 


are solely dependent upon colour for discrimination, others, 


328 OSTREADA. 


and by far the greater portion, are the result of accidental 
distortion, or the mere modifications of form, or that suppo- 
sitious sculpture which all members of a sessile genus are 
liable to. 

In the most freely-developed specimens—and these are 
less frequently met with im the adult than in the immature 
state—(the chances of the growth having been uninter- 
rupted materially diminishing with age), the shape is sub- 
orbicular, though rather longer than broad, and the sides 
are nearly equal. The texture is pearly, and in the mass of 
examples is thin, white, a little transparent, and destitute 
of any natural sculpture whatsoever. In the large coarse 
specimens, however, to which the name ephippium is usually 
restricted by collectors, the texture is moderately thick, and 
at times almost opaque; the shape is more produced, the 
sides decidedly unequal, and the surface, from the shell 
being ordinarily attached to oysters, correspondingly, though 
in a diminished ratio, sublamellar, or concentrically girt 
with undulating wrinkles. Such as are found on Pectens 
imitate their radiating ribs ; yet it is not generally difficult 
to determine, even when an Anomia is detached, whether 
the apparent coste are natural to the species, or of ex- 
traneous origin, by observing whether all the ribs emanate 
from the umbo, whence they invariably radiate in all 
essentially ribbed species of this genus. The beaks are 
acute and terminal, but bend either to the right or left: 
occasionally, also, they are subcentral and inflected. The 
upper valve is usually the more ventricose and solid; the 
lower, the thinner and more flattened; occasionally, how- 
ever, the latter—which, except at the beaks, is almost of 
equal dimensions to the former—becomes, from the neces- 
sities of its position, wholly or partially convex. The 
perforation—which in the more characteristic examples is 


ANOMIA. 329 


subovate, and almost always is broader than long, and 
generally, too, is more or less oblique—is sometimes simple 
at its edge, sometimes surrounded with a kind of reflected 
margin, which is at times appressed, at times elevated (as 
in the variety ¢ubularis where the contracted aperture 
forms a very short tubular projection). This aperture, 
which is occasionally, though rarely, suborbicular, varies 
also in its relative proportion to the size of the valves; the 
average extent of its outline, as compared to that of the 
entire shell, is about as one to three; the severed ends of 
the aperture lie sometimes far apart from each other, some- 
times become almost approximate. In general, brilliancy 
of nacre is accompanied by thinness of texture and large- 
ness of aperture. The solid and laterally projecting strip 
of shelly matter, which separates the perforation from the 
edge of the upper valve is very narrow. 

When the young is uninterruptedly developed, and 
found on smooth substances, such as the interior of dead 
bivalves, &c., it is flat, suborbicular, and quite smooth, 
with its beak projecting beyond the margin, and its per- 
foration small in proportion to the dimensions of the valve ; 
but when exposed on rough substances, it assumes quite 
as distorted an appearance as the adult shell, to which it 
approaches in almost every character. In the former case 
it is the sguamula of authors; the name cylindrica or cym- 
biformis has been attached to such as embrace the stalks 
of Lamellaria or other cylindraceous bodies. The mon- 
strosity jfornicata exhibits, to use the words of Turton, 
a large vaulted chamber under the hinge of the larger 
valve ; punctata has its upper valve embossed with tuber- 
cular prominences, and its lower with corresponding in- 
dentations arising from elevations present on the rock 
coral or other marine object on which the shell may be 


VOL. II. UU 


330 OSTREADA. 


seated: the edge of coronata, in adapting itself to the 
substance on which it has been affixed, has become ser- 
rated on one side. The nacre of the varieties cepa and 
electrica are tinged, the former with lilac or rose colour, 
the latter with yellow or rich amber colour; in both 
the perforation is peculiarly large and the lower valve 
remarkably thin. 

Our larger examples are about two inches long. and 
rather less in breadth. 

The individuals received from North America, as the 
ephippium of Gould (Invert, Massach. p. 1388), have their 
lower valve both within and without of a decided bluish 
green, with generally an opaque white internal circum- 
ference to the perforation: their upper valve displays a 
yellow umbo on a ground otherwise devoid of colouring. 
Possibly the examination of a sufficient number of ex- 
amples might elicit such other features, as to warrant 
the separation of the Transatlantic shell. 

The followimg account of the animal of Anomia ephip- 
pium is from the pen of Mr. Clark :— 

** Animal suborbicular, mantle circular, the upper por- 
tion, lining the convex valve, of very thin and _ pellucid 
texture, except at the margin, which is thick and fleshy ; 
the under valve, or that lying on the flat valve, is also 
thin, but has the appearance of being very fleshy from 
having the lower portion of the ovarium soldered to it; 
both margins are clothed with a double fringe, and they 
diminish in breadth as they approach the beaks, the 
upper one passing round the aperture of the operculum 
and there throwing out cilia, and with the under valve 
fix themselves under the beaks. The margins on the 
outer circle have long white or yellowish, thick set, very 
pointed tentacular filaments, which may be seen protruded 


ANOMIA. aon 


beyond the shell, and on the inner circle, there are long 
and short cilia of the same colour, but distributed irre- 
gularly ; the general colours of the marginal area of the 
fringes are a mixed blotchy red, yellow or purplish brown. 
No ocelli can be detected. 

‘* There are a pair of circular branchie, varying from 
pale-red to dark-brown, on each side the body which is very 
small, with very fine longitudinal and transverse vessels ; 
the plates of each pair have part of their outer surfaces 
doubled on them, thus forming circular open pouches. 

“The oval margined mouth, with its large aperture, is 
placed very high up in the dorsal ranges, and has around 
it two plain linear membranes, which are continuations 
of the branchiz, which at this point have become atte- 
nuated; these lamin expand at each side the mouth, into 
two pair of long very delicate labia, fixed by the entire 
length of the longest sides, foldmg on each other, and 
have the finest striz on both surfaces: the colour varies 
from light to dark brown. 

“« The foot is almost reduced to nothing, it is fixed to 
the body under the mouth, and is a small yellow obtuse, 
subeylindrical, deeply grooved pendulous body. 

“ The ovarium is an extensive inflated sinuated lobe, 
originating on each side the liver, coasting around the 
body, part thereof being glued to the lower portion of 
the mantle; this organ has been mistaken for a large 
foot, but its soft milky composition of separate granules, 
show that it is the organ of reproduction, and the milky 
humour mixed amongst the granules, which appear to 
spring from pyriform membranes, is probably the fecund- 
ating fluid. 

‘“‘ The ovarium varies greatly in colour, from deep ver- 
milion to quite white. 


332 OSTREADA. 


“The liver is always of the shades of green, and 
situated at the centre of the dorsal range; the passage 
from the mouth to the stomach, which is under, and 
partly enveloped by it, is very short; from it the anal 
tube descends to the centre of the body, where it makes 
a short turn, and ascends by the body, through the 
ovarium to the dorsal range, and again descends, slightly 
attached to the membrane of the latter organ, and de- 
bouches at some distance from the base of the posterior 
ventral range. 

‘“‘ Finally, as regards the animal, it is necessary to 
observe, that in this singular and unsymmetrical genus, 
even its organs, like its shell, display varieties of form ; 
from the entire animal being deposited in the convex 
valve, it only rests on the flat one, consequently, the 
organs vary, in some measure, with the figure, form, and 
depth of the concavity of the upper valve.” 

This Protean species is distributed throughout the Eu- 
ropean Seas, and on our own coast it is common everywhere. 
It occasionally occurs free with the perforation soldered 
up, as we have dredged it in the Bristol Channel. It 
ranges from low-water-mark to as deep as twenty or 
thirty fathoms (M‘Andrew). Mr. Jeffreys has taken the 
variety cylindrica in one hundred fathoms off the Zetlands. 


A. acuLeata, Miiller. 


Small ; surface radiated with regular raised strie, which are 
usually armed with prickles: no triangular cavity on the under 
valve beneath the hinge. 


Plate LV. fig. 4. 


Anomia aculeata, MistuER, Zool. Dan. Prodrom. p. 249.—Monz. Test. Brit. p. 
157, pl. 4, f. 5. — Maron and Rack. Trans. Linn. Soe. vol. 
viii. p. 103. — Turv. Conch. Diction. p. 4; Dithyra Brit. p. 


ANOMIA. 333 


233.—F Leming, Brit. Anim. p. 396.— Maceruiy. Moll. 
Aberd. p. 232.—Brit. Marine Conch. p. 123, f.73.— Brown, 
Illust. Conch. G. B. p. 70, pl. 22, f. 6. — Brucibre, Encycl- 
Méthod. Vers, vol. i. p. 73. — Dittw. Recent Shells, vol. 1. 
p. 288.— Puiirri, Moll. Sicil. vol. ii, p. 214, pl. 28, f. 1 
(probably).— Goutp, Invert. Massach. p. 139, f. 90.— 
Loven, Index Moll. Scandinay. p. 30. 

Anomia striolata, (VAR.) TurtT. Dithyra Brit. p. 233, — FieM. Brit. Animals, 
p. 396.— Maceitiv. Moll. Aberd. p. 233 ? — Brit. Marine 
Conch. p. 125.—Browy, IIlust. Conch. G. B. p. 70. 


The Prickly Anomia is a very small species closely re- 
sembling a young ephippiuwm, from which it may be dis- 
tinguished by its spinous sculpture. This is composed of 
extremely crowded vaulted scales, disposed in a more or 
less close order, which radiate in all directions from the 
umbo, and are occasionally seated on interrupted elevated 
striz or narrow costelle. When circumstances permit its 
developement, the attached valve is wont to exhibit a 
similar echinated appearance; ordinarily, however, it is 
devoid of sculpture and very thin and fragile. The undis- 
turbed shell is more or less suborbicular, the colour is 
whitish or pale ochraceous brown, and never adorned with 
coloured markings or a green interior. The umbo is 
almost marginal, and the perforation is ovate, of moderate 
size, and immediately adjacent to the hinge-margin. 

We consider the striolata of Turton to be a variety of 
this species, with more distant and less echinated strie. 
From three-eighths to half an inch may be reckoned the 
full diameter. 

Distributed everywhere around our coast in similar local. 
ities with ephippium, though probably not ranging so deep. 
It is found throughout the North Atlantic very small, of 
an uniform whitish or brownish hue with radiating vaulted 
scales; the perforation is immediately adjacent to the 
dorsal edge. 


334 OSTREADA. 


A. PAaTELLIForMis, Linnzeus. 


Surface radiated with regularly disposed wavy ribs ; a trian- 
gular cavity on the under valve beneath the hinge. 


Plate LVI. fig. 5, 6. 


Anomia Patelliformis, Linn. (not Chemn.) Syst. Nat. ed. 12, p. 1151; Noy. 
Act. Upsal. 1773, vol. i. p. 42, pl. 5, f. 6, 7.—ReErzius, 
Nova Genera Test. p. 11.— Lovin, Moll. Scandinay. 
p- 30. 
Ostreum striatum, Da Costa, Brit. Conch. p. 162, pl. 11, f. 4. 
Anomia undulatim striata, &c., CHEMN. Conch. Cab. vol. viii. p. 88, pl. 77, f. 699° 
» undulata, GMELIN, Syst. Nat. p. 3346.— Mont. Test. Brit. p. 157, pl. 
4, f. 6. — Maton and Rack. Trans. Linn. Soe. vol. yiil. p. 
103. — Rack. Dorset Catalog. p. 39, pl. 11, f. 4. —Turr. 
Conch. Diction. p. 4; Dithyra Brit. p. 230, pl. 18, f. 8, 9, 
10. — Fiemine, Brit. Anim. p. 395.— Maceiuiv. Moll. 
Aberd. p. 231. — Brit. Marine Conch. p. 122.— Brown, 
Illust. Conch. G. B. p. 69, pl. 22, f. 2, 3. — BruGiEreE, 
Encycl. Méth. vol. i. p. 74, pl. 171, f. 16,17, and pl. 184, 
f. 5, 6.—Dittw. Recent Shells, vol. i. p. 289.—Index Tes- 
taceolog. pl. 11, f. 9.— Brown, Conch. Text-book, ed. 1, 
p. 110. 
Ostrea striata, PULTENEY, Hutchins, Hist. Dorset, p. 36.— Donovy. Brit. Shells, 
vol. il. pl. 45.—Monr. Test. Brit. pp. 153, 580. 


The characters by which this apparently distinct form 
may be discriminated from ephippium, are few in number, 
but easy of observation. About twenty or thirty slightly 
flexuous radiating ribs emanate from the umbonal region 
(they are seldom if ever visible upon the umbo itself) of 
the upper valve, and thence diverging all round, crenate 
the outer margin of the shell. These are but moderately 
elevated, convex (not square) above, and are for the most 
part rather narrower than their interstices, which, as well 
as themselves, are crowdedly traversed in a concentric 
direction by very delicate and somewhat laminar striae. A 
rather narrow perpendicular dull-surfaced triangular area is 


excavated, in a somewhat shelving fashion, in that portion 


ANOMIA. Be 


of shelly matter which surmounts the aperture of the lower 
valve. 

The shape of the shell, although variable, is usually 
more ‘or less suborbicular, and has a tendency rather to 
increase in width than length. In the younger and more 
beautiful individuals the exterior is adorned with a warm 
tinge of reddish brown upon the interstitial spaces of the 
cost. The valves are generally more or less compressed, 
and the upper displays upon the central disk or area inter- 
nally (and in the young externally likewise) a darker or 
lighter tint of bluish green. The beak is prominent, but 
is not (as in ephippium) immediately adjacent to the 
margin. The perforation, which is large in the most cha- 
racteristic examples, seems rarely if ever oblique, is usually 
somewhat pear-shaped, and is divided from the edge of the 
outer valve by a comparatively broad space of shelly 
matter. 

We have never seen examples which emulate the dimen- 
sions attained to by the preceding species; one of our 
largest, which appears from the solidity of the upper valve 
to be aged, measures only a full inch and a half in breadth 
and rather less in length. 

This form has a greater range in depth than any of our 
other Anomie beginning in the Littoral and Laminarian 
regions, and living in some places, as off Cape Clear in the 
south and Cape Wrath in the north, as deep as forty-five 
and fifty fathoms. It is more abundant in the north and 
west than in the south, and on the whole is not so common 
as the preceding forms. It adheres closely to shells and 


stones, and ranges throughout the northern shores of 
Europe. 


336 OSTREADA. 


A. striata, Loven. 


With most crowded rows of minute but not prickly scales : 
umbonal region of the upper valve green ; a triangular depression 
as in Patelliformis. 

Plate LV. fig. 1, 6, and Plate LIII. f. 6. 


2 Squama magna, CHEMNITZ, Conch. Cab. vol. viii. p. 87, pl. 77, f. 697 (from 
which A. squama, GMELIN and Woop). 
2 Anomia patelliformis, Woop (not Linn.) Index Testaceol. pl. 11, f. 10. 


35 striata, LovBN, Index Moll. Scandinavia, p. 29. 


Whether this elegant shell, which is undeniably the 
striata of Loven, be entitled to specific distinction, is per- 
haps a point which may be mooted hereafter. The present 
very limited acquaintance with Anomia, of which scarcely 
any distinct exotic forms have been described or even met 
with, at least in our English cabinets, forbids a positive 
determination of what are the essential specific characters 
of the shells of this genus, and renders it advisable to 
follow the opinion of a writer who has incontestably proved 
his profound powers of observation in his several disserta- 
tions upon the Testacea of Northern Europe. 

The shape is more or less orbicular, and rarely exhibits 
much of that straightness in its dorsal outline that is so 
common in ephippium: its nearest relationship, indeed, is to 
Patelliformis, which it resembles in the dark-green hue of 
the subumbonal portion of its interior, in the dull triangular 
depression above the aperture of the inferior valve (which 
is so excessively thin, that it 1s wholly or partially broken 
in almost every individual we have examined,) in the oe- 
casional remoteness (for in most the beak is submarginal) 
of its umbo from the outer edge, the frequent radiation of 
its exterior by undulating and rather broad streaks of 
rufous brown, &e. The beautiful example we have deli- 


ANOMIA. 337 


neated, is, however, of a pure white except upon the um- 
bones, which are of a clear bluish green. The sculpture is 
very peculiar, the surface never exhibiting any of the 
characteristic ribs of the previous species. In place of 
them, it is covered with an infinity of most minute radiat- 
ing series of small depressed or imbricated (yet somewhat 
vaulted) scales, which are disposed in such extremely close 
order as to leave no visible interstitial lines: the more 
abraded, or less fully developed examples, appear simply 
impressed with most crowded radiating strie. These scales 
and striz regularly emanate from the umbo, and are not 
moulded, as it were, by the adhesion of the valves to any 
similarly sculptured body. 

Both Mr. M‘Andrew and Mr. Jeffreys have taken this 
scarce Northern shell in the Hebrides: the latter gentleman 
at Loch Carron and Ullapool. Mr. Barlee has taken it at 
Oban. It inhabits the Scandinavian seas. 


Note.—In the Cornish Fauna of Jonathan Couch, we find an Ax. inflata (pt. 2, 
p. 39,) which is assuredly the fry of one of our larger species, and probably of 
ephippium. We have not seen the types, which are in the Museum of the 
Royal Institution of Cornwall ; but give the description verbatim. 

“This which I suppose to be undescribed is a minute species, the diameter of 
the disk being about the tenth of an inch. The form is circular, the valves 
smooth and regular; but it is especially characterized by the elevation of its 
centre, which is almost as high as the diameter of the valve. From this the beak 
is bent down, and small. The specimen described, which was attached to the 
shell of a Pinna, has the summit inflated and round ; but a specimen which I 
found in Mount’s Bay attached to sea-weed, was about equally elevated, but 
pointed. Further research will decide whether these specimens belong to the 
same species. In another specimen, found with the former in Mount’s Bay, the 
beak approached but did not join the margin ; and the upper valve was character- 
ized by a number of well-marked circular raised ribs.” 


VOL. Il. x xX 


339 


ACEPHALA PALLIOBRANCHIATA, 
OR BRACHIOPODA. 


Tue researches of geologists, and the discoveries of 
scientific travellers, prove incontestably that in time and 
space there are points or regions where peculiar groups 
of organisms attain a maximum developement in variety 
of character, or number of species, or multiplicity of in- 
dividuals, constituting, as it were, a metropolis of the 
family or genus. Before and after, in geological time, 
and all around in geographical space, the number of mem- 
bers of the generic type diminishes. The great section 
of Mollusca, whose few living British representatives we 
have now to describe, is a memorable example of this 
phenomenon. The Brachiopods, though scantily distri- 
buted through existing seas, abounded in those of the 
long past, and rivalled the Lamellibranchiate bivalves in 
numbers and variety, whilst the latter were poorly re- 
presented by a very few species, members of a very few 
genera. Inferior in many features of their organization 
to the Lamellibranchiata, in the main they must rank 
as a great parallel group, equal in ordinal value, and 
aberrant in some respects from the Molluscan type. 

They are styled Palliobranchiata, because their respi- 
ratory system, instead of being disposed in separate gills, 
is combined with mantle, on which the vascular ramifi- 
cations are distributed; and Brachiopoda, because their 
apparent organs of motion are two large, variously curved, 


340 ACEPHALA PALLIOBRANCHIATA, 


tubular cirrhated arms. They do not, however, effect 
any change of place by these organs, which cannot be 
said to be feet, but are extended processes springing from 
the margins of the mouth, and therefore analogous to the 
labial palps of other bivalves. These curious organs are 
in some Brachiopods quite free; in others, attached to 
a complicated cartilaginous or calcareous skeleton. None 
of the existing mollusks of this order are capable of 
changing place. Exclusive of their brachial apparatus, 
their bodies are but small. The digestive organs and 
nervous system are simple; there is no foot; the sexes 
are distinct; the organs of sex are attached to the 
mantle. The lobes of the mantle line, and usually ad- 
here to the valves of the shell, which are not to be re- 
garded as exactly homologous with those of other bivalves, 
but each as the equivalent of two half valves of a Lamel- 
libranchiate Mollusk. The surface of the mantle is covered 
with vibratile ciliz. The muscular system is variously 
developed in different genera. Ocelli and otolitic vesicles 
are certainly present in some species, if not in all. The 
history of their developement is unknown. Their food 
is infusorial. 

The most striking feature of the animals of this great 
section—their possession of spiral fringed arms—was first 
noticed by Pallas in a Terebratula, and by Otho Frederic 
Miiller in a Crania. The researches of Cuvier into the 
external structure and anatomy of Zingula recalled at- 
tention to the group, and that famous naturalist clearly 
perceived its importance. Not, however, until the great 
comparative anatomist of England, Professor Owen, aided 
by the invaluable collections of Hugh Cuming, who will 
ever rank among the foremost of benefactors to Mala- 
cological science, undertook a minute inquiry into the 


OR BRACHIOPODA. 341 


organization of several of the Brachiopodan types, could 
our knowledge of them be said to be sufficient for a clear 
perception of their true relations with other acephalous 
mollusks. The memoir, in which Mr. Owen published the 
details of his observations, is one of the chief ornaments 
of the first volume of the Transactions of the Zoological 
Society of London. 

Professor Owen concludes that in all essential points 
the Brachiopoda closely correspond with the Acephalous 
Mollusca, and considers them “as being intermediate to 
the Lamellibrachiate and Tunicate orders, not, however, 
possessing, so far as they are at present known, distinctive 
characters of sufficient importance to justify their being 
regarded as a distinct class of mollusks, but forming a sepa- 
rate group of equal value with the Lamellibranchiata.” * 

Brachiopods are so rare or so local in the British 
seas, that ordinary collectors are not likely to meet with 
any. Not very long ago a British Brachiopod was one 
of the brighest gems in any collection so fortunate as to 
contain it. Three or four minute and undeveloped exam- 
ples of Terebratula caput serpentis, and a few Crania, 
were all we were likely to meet with after exploring the 
great majority of public or private cabinets. Of late 
years great numbers of that interesting Terebratula have 
been taken, and the Crania has also been found in quan- 
tity, so that there is no longer difficulty in obtaining an 
indigenous type of the order. 

A visit to any cabinet of fossil remains will, however, 
show that though now so scarce in this region of the globe, 
they were once present in myriads. To have any correct 
notion of the varied modifications of form and structure 
presented by Palliobranchiate Mollusks, it is absolutely 


* Zool. Trans. vol. i. p. 159. 


342 ACEPHALA PALLIOBRANCHIATA. 


necessary to examine fossil as well as recent forms, nor 
can the comparatively few of the latter now surviving in 
existing seas, convey any just idea of their systematic 
relations, so many of the connecting links between them 
being lost to life. A visit to the quarries at Dudley, or 
an Irish limekiln, or an oolitic section on the Dorsetshire 
coast, or a green sand ravine in the Isle of Wight, will 
furnish more sectional types, and afford more information 
about the Brachiopods, than an examination of the finest 
collection of the living species. In each of the above 
excursions a different set of forms would be collected, for 
the Brachiopods of the older paleeozoic epoch differed ma- 
terially from those of the newer, whilst differences as great 
are seen between those of the older and new secondary 
epochs. Many of the paleozoic genera have altogether 
disappeared when we rise among the secondary rocks, and 
in the latter we find forms which closely remind us of 
existing species, but which, though very near, are yet un- 
questionably distinct. In formations of all epochs a few 
generic types are common, and the Lingule of the earliest 
sedimentary formations, presenting traces of organic life, 
strikingly remind us of the species of that curious group 
living in exotic seas at the present day. 


345 


TEREBRATULIDA. 


Tue genus Terebratula of Brugitre—the original Ano- 
mia, although the latter name has been appropriated, as 
we have seen, by a very different assemblage of shell-fish— 
included within itself those shells which present a general 
similarity of form, due to the inequality of their valves 
and the perforation on or under the beak of the upper 
and larger valve for the passage of a muscular peduncle 
by means of which the animal is fixed to rocks, or shells, 
or other extraneous bodies. Most writers on existing 
shells use the term T'erebratula in the Brugierian sense, 
but paleontologists have become more and more im- 
pressed with the necessity of breaking up this really vast 
assemblage of species, not merely on account of their 
number, which would be but a sorry reason for generic 
dismemberments, but because included in it we find lesser 
groups exhibiting important characters of structure, evi- 
dently of high value, whether we consider the features 
of the shell or the arrangements of the soft parts within 
it. Ag these subdivisions of the old genus Terebratula 
appear to have a value fully equal to the generic sepa- 
rations which we have admitted among the Lamellibran- 
chiata, we feel bound to adopt them, however much our 
doing so may seem an innovation on conchological practice. 

Baron Von Buch, one of the most philosophical of living 
paleontologists and geologists, was the first clearly to see 


344 TEREBRATULIDZ. 


the necessity for a revision of the Terebratule, and all that 
has been done of late years on the subject, must be regarded 
as fruit sprung from seed sown by him. In our country 
his footsteps have been followed with varied success by 
Philips, Morris, M‘Coy, and King. Their researches 
have been mainly directed to the elucidation of the fossil 
species. Very lately M. Alcide d’Orbigny has directed 
his sagacious mind to this important inquiry, and has 
brought, with a bold hand, the work of his predecessors 
and of himself, powerfully to bear upon both recent and 
fossil forms. According to his view of the generic sec- 
tions into which they should be divided, each of our 
few British Terebratule would become a member of a 
different genus, and even fall under distinct tribes. We 
prefer regarding them as members of a single tribe, and 
as forming part of three very distinct and easily re- 
cognised genera. 


HYPOTHYRIS, Puituies. 


Shell tumid, thin, mequivalve, equilateral, its surface 
marked with radiating striz or grooves, and never punc- 
tated. Beak of upper valve entire, the perforation beneath 
it triangular and open, reaching the margin. No cardinal 
area. Apophyses consisting of two separate, curved, mo- 
derately developed blades projecting from the hinge of the 
lower or imperforate valve. 

Animal with spirally coiled buccal appendages or arms, 
not fixed by a cartilaginous or testaceous skeleton. 

Only two existing forms of Terebratule with non-punc- 
tated shells are known, the one about to be described, 
and the Terebratula nigricans of G. B. Sowerby, the 
habitat of which is unknown. In the fossil state, how- 


HYPOTHYRIS. 345 


ever, great numbers of shells nearly allied to Hypothyris 
are found. The propriety of separating this group from 
other Terebratule cannot be called in question, for structure 
of beak and foramen, peculiarity of the apophysary ap- 
pendages, arrangement of the brachial organs of the animal, 
and microscopic structure of the shell all combine to define 
a natural and extensive genus. 

The account given by Dr. Carpenter of the microscopic 
structure of the shell of our British Hypothyris is so im- 
portant in its bearings that we transcribe it in his own 
words :—‘‘ This shell,” he writes, ‘“‘is remarkable for its 
divisibility into thin micaceous plates, which may be split 
into laminz of extreme tenuity. I do not know any one 
of the Lamellibranchiate bivalves whose shell corresponds 
with it in this respect, except Placuna and Anomia, which 
evidently verge towards the Brachiopoda. This facility of 
lamination characterises a large number of the fossil spe- 
cies of the group; especially those which correspond with 
the one under consideration, in its peculiar characters. 
The natural lamine thus obtained frequently afford better 
subjects for microscopical examination than can be pro- 
cured by making sections in the ordinary manner. When 
these laminze are examined with a good microscope they 
are found to present a most remarkable and characteristic 
appearance; they are traversed by a very regular series 
of lines, usually nearly straight, but sometimes slightly 
curved, and running quite parallel to each other. When 
the broken extremities of these natural lamin are exa- 
mined, it is seen that the lines in question are produced 
by sharp foldings of the shelly layer, which foldings are 
parallel to each other; and this view is confirmed by 
examination of the decalcified membrane of which only 
one continuous stratum exists in each lamina. When the 

VOL. I. yx 


346 TEREBRATULIDA. 


natural internal surface of the shell is examined, a very 
beautiful appearance is presented by it; a most regular 
imbricated arrangement is seen, exactly resembling a tiled 
roof, in which the lower margins of the tiles are rounded, 
instead of being quadrangular. If a portion of the surface 
be slightly rubbed down, so that the connection of their 
tile-like markings with the interior structure can be traced, 
it is seen that they are the extremities of the longitudinal 
folds just mentioned, each row of them belonging to one 
lamina, and a series of the lamine cropping out, one 
beneath another.” 


H. psirracea, Chemnitz. 


Surface blackish, not punctulate, with radiating striz. 


Plate LVII. fig. 1, 2, 3. 


Daviza, Catal. Cabinet, vol. i. pl. 20, f. b. B. 

Anomia rostrum-psittact, CHEMN. Conch. Cab. vol. viii. p. 106, pl. 78, f. 713. 
» psittacea, GMELIN, Syst. Nature, p. 3348.—Turr. Conch. Diction. p. 5, 
f. 42, 43, 44.—Dittw. Recent Shells, vol. i. p. 296.—Index 
Testaceolog. pl. 11, f. 27.—Mawe, Linn. Conch. pl. 15, f. 3. 
Terebratula psittacea, LAM. Anim. s. Vert. (ed. Desh.) yol. vii. p. 333.—Tort. 
Dithyra Brit. p. 236.—FLEMiING, Brit. Animals, p. 368. 
—Tuompson, Ann. Nat. Hist. vol. xii. p. 433.—Brit. 
Marine Conch. p. 127.—Brown, Illust. Conch. G. B. 
p. 68, pl. 46, f. 2, 3, 4—Anprr, Cat. Moll. Northum- 
berl. and Durh. p. 74.—Crovucn, Introd. Lam. Conch. 
pl. 13, f. 4.—Sowxrrsy, Genera Shells, Terebratula, f. 
5; Thesaur. Conch. vol. i. p. 342, pl. 71, f. 78, 79, 80.— 
SoweErsy (Junior), Conch. Manual, f. 202.—Goutp, In- 


vert. Massach. p. 142, f..91.—ReExvzE, Conch. Systemat. 
pl. 126, f. 5. 


Hypothyris psittacea, Kine, Ann. Nat. Hist. vol. xviii. p. 238. 


Turis quaint and sombre-looking species, one of the very 
searcest of our native shells, is of a somewhat globosely 
triangular shape, being acuminated above, and rather 
abruptly dilated below: it is very thin, gibbous, not 


HYPOTHYRIS. 347 


polished, yet sometimes a little glossy or even slightly 
nacreous, and of a black or sooty hue; the surface, except 
at the extremities, is radiated with simple and rather 
closely disposed striz (which become stronger as they 
recede from the umbones), besides being marked with more 
or less distinct and numerous concentric lines of increase. 
The valves are unequal; the upper or larger one, which 
above is compressed at the sides, is likewise somewhat 
flattened below, on account of an expanded but very 
shallow mesial hollow, which excepting at its termination 
is but little prominent; the lesser or lower one is the more 
swollen, and is neither indented nor ridged. The acumin- 
ated beak, which is perforated by a narrow triangular 
orifice (which is not entire), leans very considerably over 
the nestling and tumid umbo of the lesser valve. The 
upper edges of the larger valve are much produced, and 
decline so profoundly as to run at acute angles to each 
other. The marginal outline (which is not crenated) is 
peculiarly sinuous, the edge of the perforated valve indent- 
ing that of the entire one on both sides near the umbones, 
and likewise along the course of the mesial hollow. The 
internal cardinal appendage consists of two recurved not 
very long blades, that project, one on either side, from 
beneath the umbones. 

The animal of this remarkable Brachiopod has been 
examined by Professor Owen. He states that from the 
two small processes, constituting the skeleton in this 
species, and continued from the sides of the hinge of the 
imperforate valve, “two spiral arms arise, fringed on 
their outer margins, but quite free excepting at their 
origins. When contracted they are disposed in six or 
seven spiral gyrations, decreasing towards their ex- 
tremities; and, when completely unfolded, they extend 


348 TEREBRATULID&. 


beyond the shell twice its longitudinal diameter. The 
mechanism by which the arms are extended is single and 
beautiful: the stems are hollow from one end to the other, 
and are filled with fluid, which, being acted upon by the 
spirally disposed muscles composing the parietes of the 
canal, is forcibly injected towards the extremity of the 
arm, which is thus unfolded and protruded outwards. 
The alimentary canal commences by a small puckered 
transverse mouth, which is situated, as before mentioned, 
immediately behind the folded extremities of the arms, 
and opens opposite the middle line of the perforated valve. 
The cesophagus, after having passed through the membrane 
inclosing the viscera, makes a slight turn on itself and 
advances straight towards the opposite valve; it then 
suddenly expands into a large oval stomach, from the 
sides of which the canals branching out into the hepatic 
follicles are continued. The intestine returns in a direc- 
tion towards the perforated valve, inclines to the right 
side, and makes a slight bend forward before perforating 
the circumscribing membrane, in order to terminate be- 
tween the mantle lobes on that side. The whole ali- 
mentary canal thus forms a loop, whose convexity is turned 
towards the imperforate or upper valve.” * 

The interesting paper of Mr. King, in the eighteenth 
volume of the Annals of Natural History, has dispelled 
the doubts which had long been entertained respecting 
the indigenousness of this species. In it is recorded the 
fact of a psittacea having been brought up from the depth 
of thirty fathoms at a distance of twenty-five miles from 
the northern coast of Northumberland, dead, but hanging 
on the beard of our common large Modiola. Mr. Maclaurin 


* Owen in Zool. Transactions, vol. i. p. 152. 


TEREBRATULA, 349 


has likewise procured it from the Berwickshire coast 
attached to the lines of the Caldingham fishermen (Ber- 
wickshire Nat. Club. vol. i. p. 213). In an interleaved 
copy of Laskey’s “ Catalogue of North British Testacea,” 
which we possess, and which formerly belonged to Laskey 
himself, is this MSS. entry, “ Terebratula Psittacea: the 
under valve was found by me on the shore at Aberlady 
Bay at low water, and since, a perfect specimen (has 
been taken) by dredging in the deeps, Frith of Forth, 
20th July, 1825.” The reputed South of England and 
Dublin Bay specimens are more questionable; indeed, 
there is every reason to suppose that they were exotic. 
Mr. R. A. C. Austen informs us that specimens have 
been sold in the south of Devon as British by fishermen 
employed in the Newfoundland fishery, and who, on in- 
quiry, proved to have brought them from the banks of 
Newfoundland. 

This shell lives more plentifully in the seas of Boreal 
America, Greenland, and Norway, and is found fossil, 
though rarely in pleistocene beds on both sides of the 
Atlantic. 


TEREBRATULA. Bruerere. 


Shell imequivalve, equilateral, regular, tumid or de- 
pressed, smooth, grooved, ribbed, or marked with radiating 
strie, always punctated. Upper valve with its beak 
perforated; perforation entire, and separated from the 
hinge by a deltidium or area more or less developed, 
or incomplete and bounded by nearly obsolete deltidia. 
Hinge of two lateral teeth entering the upper valve. 
Apophysary system composed of more or less complicated 
looped cartilaginous or calcareous processes, free except at 


350 TEREBRATULIDZ. 


their crigin from each side of the beak of the imperforate 
and inferior valve. 

Animal with strongly cirrhated, looped, or contorted 
arms fixed to the apophysary skeleton. 

Among living Brachiopods the species of the genus 
Terebratula, restricted as we here define it, may at once 
be recognised by their punctated shells with perforated 
beaks and foramina, in most instances completed by a 
deltidium, whilst on opening living or well-preserved dead 
specimens, the skeleton will be seen presenting the form 
of an apparatus composed of shelly or horny loops. The 
majority of living species of the old genus Terebratula, and 
an immense number of fossil forms ranging even to the 
Paleeozoic epoch, belong to the genus so defined. 

M. Alcide @Orbigny proposes a minuter subdivision of 
the group, going so far as to regard the genus, even as 
above restricted, in the light of forming part of two 
families. In one group he includes four genera, viz., Tere- 
bratula, distinguished by having no area and a round 
foramen, encroaching more upon the beak than on the 
deltidium, which is composed of two pieces; Terebratella, 
having an area, and a two-pieced deltidium, upon which 
the foramen encroaches; Terebrirostra, having a delti- 
dium formed of a single piece, and a foramen encroaching 
upon it; and Lssirostra, having a similar deltidium, but 
which is not encroached upon by the foramen; the latter 
being confined to the beak, and placed on its outer portion. 
The only one of these genera which includes an existing 
British species is Terebratula, im which T'. craniwm has its 
place. Our other native form, the caput serpentis, is placed 
by M. @Orbigny in his T'erebratulina, forming part of his 
family Magaside, in which the shells have no deltidia ; 
and he distinguishes the genus from Magas by its trun- 


TEREBRATULA. 351 


cated beak and eared yalves. The distinction is very 
probably a good one. 

We extract from Dr. Carpenter’s report on the micro- 
scopic structure of shells the following very important 
account of the peculiar organization of the shell in our 
native Terebratula caput serpentis, which illustrates the 
distinctive features of the shell of Terebratula as compared 
with that of Hypothyris. 

‘* When a thin portion, which has been preserved with 
the animal in spirit, is ground down from the inner side, so 
as to leave the outer surface unchanged, it will be seen that 
each perforation in the shell is covered in by an oval mem- 
branous disc, whose texture appears very firm. When a 
thin section thus made is exposed to the action of dilute 
acid, so as to remove from it the calcareous matter, it will 
be seen that these dises are connected together by a layer 
of very pellucid membrane, in which no distinct structure 
can be made out ; this membrane, differing as it does from 
the membranous basis of the interior layers of the shell, 
is probably to be regarded in the light of an epidermis. 
When a portion of the shell, not reduced in thickness, is 
completely decalcified by immersion in dilute acid, and the 
membranous residuum is then examined, a very remarkable 
structure presents itself, such as is found in no shells of the 
Lamellibranchiate Bivalves. Attached to the membranous 
films are a series of tubular appendages, corresponding in 
diameter to the perforations in the shell, and arranged at the 
same distances. The free extremities of these appendages 
are much larger than those by which they are attached to 
the membrane, and have distinct ceca] terminations, which 
appear by the straightness of their border to have been 
flattened against the discs that closed the orifices of the 
perforations in the shell. Indeed in some instances these 


302 TEREBRATULIDA. 


dises have remained adherent to them, when the shell 
membranes were torn asunder; and are seen edgeways, as 
in fig. 3, a.* There can be no doubt, therefore, that these 
membranous c@ca occupied, in the living animal, the per- 
forations already described as penetrating the shell from 
one surface to the other. This will be still more evident 
on reference to fig. 39 of my former report; in which it 
will be seen how exactly the shape of the ceca corresponds 
with that of the perforations, when the latter are laid open 
lengthways by a section of the shell perpendicular to its 
surface. The Jower margin of that figure corresponds with 
the outer surface of the shell, and the diameter of the per- 
forations is seen to be there greatly increased. With 
regard to the office of these ceca, however, I am unable as 
yet to give any distinct explanation. ‘Their contents are of 
a brown granular character, in which I have recognised 
distinct cells (fig. 4), such as are to be met with in the 
tubuli and follicles of ordinary glands ; and their whole 
aspect satisfies me that they must be regarded as possess- 
ing a glandular character. I have not been able, however, 
to discover the nature or destination of their secretion. 
The internal orifices of the perforations obviously consti- 
tute the outlets of the ceca; but there does not appear to 
be any system of tubes or canals for collecting the matters 
poured out from them, each cecum having its distinct and 
independent termination on the internal surface of the 
shell. Although the unusual degree of adhesion between 
the mantle and the shells of Terebratule, first noticed by 
Professor Owen, formerly led me to suspect that the 
mantle might send prolongations into the perforations of 
the shell, I have not been able to discover any vestige of 
such. On the contrary, it has appeared to me that the 


* See plate in the work cited. 


TEREBRATULA. Sue 


mantle, which is a nearly homogeneous membrane where 
not traversed by vessels, is simply applied to the internal 
orifices of the ceca, and continued over them; no trace of 
any connection with them being visible when it is detached 
from the shell. I may mention, however, that I have 
found the surface of the mantle in contact with the shell 
to be scattered over with minute cells, corresponding in 
size and aspect with those contained in the cecal tubes. 
“The physiological purpose of this curious structure, 
therefore, is at present a mystery ; but there can be little 
doubt that it is a very important one in the economy of 
the animal, when we see the shell thus rendered subservient 
to the special protection of these ccecal appendages.” 


T. cAPUT-SERPENTIS, Linneus. 


Subovate ; attenuated above ; whitish, costellated. 
Plate LVI. fig, 1, 2, 3, 4. 


Anomia caput-serpentis, LINN. Syst. Nat. ed. 12 (not ed. 10), p. 1153; Fauna 
Suecica, ed. 2, p. 521; Acta Upsaliens. 1773, vol. 1. 
p- 41, pl. 5, f. 3.— Born, Mus. Ces. Vind. p. 119.— 
Cuemn. Conch. Cab. vol. viii. p. 103, pl. 78, f. 712, 
and yol. xi. p. 248, pl. 204, f. 2013.—Ditiw. Recent 
Shells, vol. i. p. 293.—Index Testaceolog. pl. 11, f. 22. 
retusa, LINN. Syst. Nat. ed. 12, p. 1151; Fauna Suecica, ed. 2, p. 521. 
—Diuiw. Recent Shells, vol. i. p. 292. 
pubescens, LINN. Syst. Nat. ed. 12, p. 1153.—Scurérer, Einleit. Conch. 
vol. iii. p. 397, pl. 9, f. 10.— Ditiw. Recent Shells, vol. i. 
p- 293.—Index Testaceolog. pl. 11, f. 20. 
» (nov. spec.), PENNANT, Acta Upsaliens. 1773, p. 39, pl. 5, f. 4. 
Terebratula pubescens, MiiLuER, Zool. Danic. Prodromus, p. 449, No. 3007. 
caput-serpentis, LAM. (not Retzius), Anim. s. Vert. (ed. Desh.) vol. 
vii. p. 332. — SowxErBy, Genera of Shells, Tere- 
brat. f. 2.—Puriiert, Moll. Sicil, vol. i. p. 95, pl. 
6, f. 5, and vol. ii. p. 66.— RexEve, Conch. Sys- 
temat. pl. 126, f. 2.— Sowxrsy, Thesaur. Conch. 
vol. i. pl. 68, f. 1 to 4, and pl. 72, f. 116. 

2s costata, Lowe, Zoologic. Journal, vol. ii. p. 105, pl. 5, f. 8, 9. 

oy aurita, FLEMING, Philosop. Zool. vol. ii. p. 498, pl. 4, f. 5; Brit. 


” 


” 


” 


VOL. Il. ZZ 


854 TEREBRATULIDA. 


Animals, p. 369.—Brit. Marine Conch. p. 127.—Brown, 
Tilust. Conch. G. B. p. 68. 
Terebratulina caput-serpentis, D’OrBIGNy, Pal. Franc. T. C. vol. iv. p. 58. 
Davina, Catalog. Cabinet, vol. i. pl. 20, f. F.—Pout, Test. Sicil. vol. ii. pl. 30, 

f. 15 (part of group),—Encycl. Méthod. Vers, pl. 246, f. 7. 

Although liable to no inconsiderable amount of vari- 
ation in form, this shell is always more or less of a rounded 
pentagonal, and somewhat egg-shaped figure, its general 
outline ranging from narrow subovate to broadly obovate ; 
the distance from the beaks to the base always exceeds 
(and very greatly so in the young) the space between the 
lateral extremities. Its valves, which are moderately and 
not very unequally ventricose, are slightly translucent, 
devoid of polish, not very thin, and of an uniform squalid 
white, but frequently appear stained with two buff-coloured 
spots, which, however, are only the result of the imperfect 
removal of the animal. The surface is everywhere covered 
with very numerous radiating dichotomous or forked 
costellee, which are generally of the same breadth as their 
interstices, and are far coarser in the fry (and consequently 
upon the umbonal region of the adult) than towards the 
slightly emarginated base of the mature shell; which 
difference, the absence of basal retusion at that stage of 
growth, and the circumstance (not unusual at any period 
of increase) of being found invested with a supposititious 
epidermis of downy sponge, induced the early separation of 
the young under the epithet pubescens. The marginal line, 
which is delicately subcrenulated within, is flexuous at the 
sides, and the lateral edges of the smaller valve approach 
each other at the beak in an angle, that is usually an 
acute one in the young, a right or even a slightly obtuse 
one in the adult. The larger valve is somewhat rostrated ; 
the perforation is moderate in size, somewhat oblique, 
and not entire. The cardinal area is rather flattened, and 


TEREBRATULA. 395 


the deltidia are almost obsolete. The internal appendage, 
which is always attached to the lesser valve, is very small, 
not extending more than one third the distance to the 
ventral edge; it is arched and vaulted below. There is 
occasionally, in those individuals whose bases are the more 
emarginated, an obscure indication in one or both valves 
of a broad and shallow mesial groove. A fine individual 
measured eleven lines from the apex to the base, and three 
quarters of an inch from side to side. 

The arms or buccal appendages of the animal occupy 
the greater part of the cavity of the shell. They are fixed 
to and follow the course of the apophysary skeleton, and 
appear, when the shell is forcibly opened, in the form of 
a pair of brilliant orange or crimson fringed loops lodged 
in each half of the cavity of the imperforate valve. The 
outer margins of each loop bear long cirrhi also of a 
brilliant orange or crimson hue, and though the arms 
themselves cannot be protruded, these cirrhi are very 
extensile; when the animal is lively, the two valves 
separate and gape for no very great distance from each 
other in front, and from their sides are seen the long 
crimson cirrhi extended like a pair of double fringes, and 
borne somewhat stiffly and with a slight curve outwards. 
Towards the edge of the strongly adherent mantle attached 
to each valve, are placed at regular imtervals about forty 
small cirrhi of a softer texture, which do not appear to 
be protruded, at least conspicuously, beyond the edges of 
the shell. These cirrhi are tinged with crimson also. 
At their bases are seen, when a high magnifying power 
is used, coloured dots and cavities with vibrating cor- 
puscles, which may be regarded as ocelli and otilitic cap- 
sules. The whole surface of the mantle is studded with 
vibratile cilia. On each side of the inner surface of the 


356 TEREBRATULIDA. 


perforate valve is seen an ovarium of an oblong shape and 
brilliant vermilion colour, and extending beyond these 
ovaria in radiating fashion, are the yellowish glandular 
masses of the liver. 

This interesting mollusk was first added to the British 
Fauna by Dr. Fleming, to whom, indeed, we are indebted 
as the first naturalist who noticed our indigenous Brachio- 
poda. He found it at Ullapool, in Loch Broom. It was 
afterwards found by the Rey. J. Berkeley at Oban. In 
each case a single specimen only was taken. Latterly it 
has been taken in many localities, in from ten to fifty 
fathoms, on the west coast of Scotland, especially by Mr. 
Jeffreys, Mr. M‘Andrew, and Mr. Barlee. The following 
habitats will show its range in depth: Loch Fyne, in from 
fifty to thirty fathoms, plentiful; off Lismore, near Oban, 
in from twenty to thirty fathoms, plentiful ; abundant in 
eighteen fathoms off Armadale, in the Sound of Skye. 
In twenty to ninety fathoms off Mull; in thirty fathoms 
off Raza. On the Lingbank, forty miles west of Zetland, 
in fifty fathoms; and in forty fathoms off Fitful Head 
(M‘Andrew and E.F.). <A single specimen from the 
north of Ireland is contained in the Ordnance Survey 
Collections (W. Thompson). Bantry Bay (Dr. Arm- 
strong). It lives attached to stones and shells ; some- 
times, as Mr. Jeffreys observes, to sea-weeds. 

This species ranges throughout the European seas, but 
south of Britain it appears to occur only at considerable 
depths. It extends its range to the Arctic seas, and is 
very nearly allied to the 7’. septentrionalis of the coasts 
of the United States. 

As a fossil, it is found in tertiary strata, and if the 
cretaceous 7. striatula be identical with it, is one of the 
most ancient of existing animals. 


TEREBRATULA. 300 


T. cranium, Miiller. 


Surface smooth, whitish, minutely punctulate. 


Plate LVII. fig. 11. 


Terebratula cranium, MUuiErR, Zool. Dan. Prodromus, p. 249, No. 3006.— 

Mont. Trans. Linn. Soe. vol. xi. p. 188, pl. 13, f. 2.— 

Tort. Dithyra Brit. p. 236.—FLemineG, Brit. Animals, 

p. 368; Treatise Mollusc. Anim, pl. 14, f. 49.—Brit. 

arine Conch. p. 126.—Browy, Illust. Conch. G. B. p. 

68, pl. 22, £. 10, 11, 12.—Lovin, Moll. Scandinay. p. 29. 

Anomia cranium, GMELIN, Syst. Nat. p. 3347.—Turt. Conch. Diction. p. 5.— 

Dittw. Recent Shells, vol. i. p. 294 (in part; not synonyms). 

Terebratula vitrea, FLEMING (not Born nor Chemn.), Edinb. Encyel. vol. vii. p. 
96, pl. 206, f. 2; Philosophy of Zoology, pl. 4, f. 4. 


The shape of the Skull Terebratula is ovate or obovate, 
being but moderately contracted (yet slightly acuminated) 
above, and but little arcuated below; the central portion 
of the ventral margin is occasionally a little straightened. 
The shell is rather gibbous, smooth, glossy, somewhat 
diaphanous, and of an uniform squalid white or yellowish 
horn-colour. The valves are almost equal in convexity, 
and devoid of either ridge or mesial groove: the larger 
or upper one is somewhat produced above, slightly re- 
curved, and obliquely truncated at the tip, displaying a 
large perforation whose margin is not entire or united. 
The lower or smaller valve is a little flattened, and the 
slope of its dorsal edges is decided but not abrupt, and 
generally more or less convex. The suture or junctional 
line of the valves isa little, but not particularly sinuous, and 
quite entire. The cardinal area is indistinct and rounded ; 
the deltidia are small, linear, and separate. The internal 
appendage, which is large, extending two-thirds the dis- 
tance from the cardinal margin, is composed of two lateral 


358 TEREBRATULIDA. 


loops, one on each side, which, folding back again, unite 
in a single very ample loop above. 

The recorded size of one of the examples described by 
Montagu, was an inch and an eighth from the beak of the 
larger valve to the ventral margin, and seven-eighths of an 
inch when measured from side to side. These dimensions 
somewhat exceed those of an individual, full-grown to all 
appearance, that we received from the north of Europe, 
which only measured eleven lines and a half by nine and 
two-thirds. 

The discovery of this species as a British production, is 
due to that veteran naturalist, Dr. Fleming, who forwarded 
an account of his obtaining a group of three individuals 
(we presume the one delineated in his Philosophy of Zoo- 
logy) to Col. Montagu, who described the shell at large 
in the eleventh volume of the Linnean Transactions. He 
had obtained it from a cod-line in deep water to the 
eastward of Bressay in Zetland. Our own drawing is 
copied from the figure in the last-named work, aided by a 
Swedish example, for as two out of the three original types 
have been lost (those given to Leach and Montagu) the 
liberal discoverer has not unwisely refused to trust the 
unique British example still left him, to the risks attendant 


upon its transit from Scotland. 


We entertain but little doubt that the Anomia Tere- 
bratula of Turton’s Conchological Dictionary, all mention 
of which was omitted in his subsequent work on British 
Bivalves, was identical with this species, which the Doctor 
at that time, by his own confession, had never seen. His 
reference for a figure is to Da Costa’s Elements of Concho- 
logy, pl. 6. fig. 3 (probably the nearest likeness to the 


MEGATHYRIS. 359 


shell intended he was acquainted with), which represents 
the 7’. vitrea, a closely allied species with an entire fora- 
men, and a shorter cardinal appendage. From the state- 
ment in the Dictionary that the single specimen dredged 
alive in Dublin Bay had been deposited in the Museum of 
the Dublin Society, a search has more than once been insti- 
tuted for it, the result of which shows that a Terebratula 
thus marked is certainly present (Thompson), but is the 
psittacea, a species that by no means harmonizes with the 
description of the shell in question, and which, moreover, 
was well known to, and adequately described by the Doctor. 
Hither, then, the locality has possibly been appended to 
the wrong diagnosis (if, indeed, there be any connection 
between the ticketed example and Turton’s observation), 
or not improbably the individual described, being, in truth, 
the exotic vitrea, havmg been detected as spuriously in- 
digenous, was purposely left out in the later and more 
original “ Dithyra Britannica.” 


MEGATHYRIS. A. p’OrRpBIGNy. 


Shell inequivalve, inequilateral, semi-orbicular, com- 
pressed, often strong, surface smooth, or with radiating 
ribs, always punctated. Area large, triangular, with a 
large incomplete foramen under the beak of the upper 
valve, and impinging on the lower; no deltidium. No 
free apophysary system, but one or more ribs or dissepi- 
ments rising from the inner surface of the smaller valve. 

Animal with contorted or spiral arms fixed to the 
margin of the apophysary ribs and cardinal teeth. 

The very rare and minute Terebratula cistellula of Mr. 
Searles Wood appears to belong to the genus Megathyris 
of D’Orbigny, of which Terebratula detruncata, and some 


360 TEREBRATULIDA. 


other Mediterranean species, are better known examples. 
Several species are known fossil, ranging as far back as the 
Cretaceous epoch. They differ so materially from the 
Terebratule properly so called, that Dr. Philippi has been 
induced to consider them as members of the fossil genus 
Orthis, with which, however, they have no near affinity. 
M. Alcide d’Orbigny has associated Megathyris with 
Thecidea, forming of these genera his Thecidida, the second 
family of his second order, Abrachiopoda of Palliobranchi- 
ata.* But, though fully prepared to admit the just claims 
of these brachiopods to generic distinction, we can scarcely, 
in the present state of our knowledge, regard them as 
farther removed from Terebratula proper than Lingula, 
Productus, or OCrania, as M. @Orbigny would place them; 
whilst he associates them in the same great group with the 
anomalous Rudiste, which appear really to have much closer 
relations with Crania. Although Philippi describes Tere- 
bratula detruncata as having no arms, but only cirrhi 
attached to the apophyses, our own examination of that 
animal would rather go to maintain the existence of true 
but fixed arms; and in the curious Orthis anomioides of 
Scacchi and Philippi (which is the Terebratula depressa 
of the “ Report on the Mollusca of the AZgean”), the 
latter eminent malacologist figures and describes two perfect 
spiral cirrhigerous arms, the species in question evidently 
having no very distant affinity with that which we are 
about to describe. 

The few living species known of this interesting genus 
are inhabitants of deep—often very deep—water, where 
they are found adhering to stones and corals. It is most 
likely that, generally speaking, the Orthidiform brachio- 
pods indicate a considerable depth of water, and that their 


* D’Orbigny, “Terrains Crétacés,” vol. iv. p. 7. 


MEGATHYRIS. 361 


presence abundantly in a sedimentary deposit should lead 
to such an inference respecting the circumstances under 
which the stratum was formed. 


M. cisteLLuLA, Searles Wood. 


Minute, not ribbed ; truncated at the umbones, 


Plate LVII. fig 9. (magnified). 


Terebratula cistellula, SEARLES Woop, Annals Nat. Hist. vol. vi. p. 253 
(fossil). 
[ seminulum? Jurrreys, Ann. Nat. Hist. vol. xix. p. 312. 


The extreme minuteness, and the scarcity of specimens, 
of this the smallest of existing Terebratule has prevented 
us from giving so detailed an account of the species as 
we could have wished. 

The shape, even in the few examples we possess, has a 
remarkably wide range of variation. That which we have 
figured, and which has a greater appearance of regularity 
than the majority of individuals, has its contour almost 
hemispherical, but the figure of certain examples is assuredly 
much more orbicular, but always more or less truncated 
above. ‘The valves are rather depressed, and seem nearly 
equal to each other in convexity and extent; they are a 
little pellucid, tolerably strong for their size, are devoid 
of radiating striz, having only some concentric lines of 
growth, and are wholly or partially covered with minute 
raised dots. Their colour is tawny-yellow or pale yel- 
lowish-brown ; but this hue may possibly be caused by 
the presence of the dried animal. The hinge line is 
straight and much produced; the central retusion of the 
opposite margin is shallow but distinct. The mesial groove 
of the lower or ventral valve is well marked, and on either 


VOL. Il. oe 


362 TEREBRATULIDA. 


side of it the surface is a little tumid: the corresponding 
elevation in the upper or dorsal valve, if present at all, 
does not appear prominently developed. The umbones are 
scarcely raised above the hinge-line, and are habitually 
more or less abraded. The cardinal area is depressed and 
triangular; the foramen is extremely large ; the chief por- 
tion of it is situated in the dorsal valve, the circuit being 
completed by the hinge-margin of the other, which is often 
a little concave (perhaps from friction) at that part. The 
inner edge is not crenated, but is somewhat radiatingly 
scabrous. 

We have not been willing to destroy our examples by 
the examination of the internal appendages; judging from 
analogy it is probable that they closely resemble those of 
detruncata,* the species, which of those delineated in 
Sowerby’s excellent monograph of Terebratula, most nearly 
approaches it in general characters. The shape seems 
nearer to the decollata of the same work. Individuals 
measuring the eighth of an inch from side to side may be 
accounted large; indeed few of those we have seen exceed 
a single line. 

This rare and curious little Brachiopod was originally 
known only in the fossil state, having been discovered by 
Mr. Searles Wood in the Coralline Crag of Sutton. From 
that active and observant paleontologist it received a 
name, but was announced without any description or figure. 
In the Annals of Natural History for July, 1847, Mr. 
Jeffreys announced that he and Mr. Barlee had lately 
procured, by dredging off Skye, in forty fathoms, a few 
valves of a shell which he referred with doubt to the Zere- 


* An example of this species was found among Turton’s shells, with the loca- 
lity, “ Torbay,” attached. Unfortunately, no dependence can be placed in any 
statements of his respecting the indigenousness of any of our doubful Testacea- 


MEGATHYRIS. 363 


bratula seminulum of Philippi. During the summer of the 
same year Mr. M‘Andrew procured a number of specimens 
of a minute Terebratula attached to a stone dredged in 
thirty fathoms’ water off Croulin Island, near Skye. Some 
of these he forwarded to the meeting of the British Asso- 
ciation at Oxford, where they were hailed with pleasure 
by zoologists and geologists as the living representatives 
of the supposed extinct crag fossil. They subsequently 
proved identical with Mr. Jeftreys’s shell. Mr. Jeffreys 
has just communicated to us the interesting information 
that two specimens have been taken this summer (1849) 


by Mr. Barlee at the haaf, or deep-water fishing-grounds 
of Zetland. 


564 


CRANIADA. 


Turoven certain curious shells, belonging to extinct 
genera, we can trace a very gradual passage from Tere- 
bratula and its allies to the patelliform Brachiopods, con- 
stituting the family of which Crania may be regarded as 
the type. In this group the shell is either fixed to extra- 
neous substances by the agglutination of one of its valves, 
or by a pedicle passing through a fissure or perforation in 
the lower valve. Most probably all the Craniade are in 
some stage of their existence affixed by a pedicle. The 
living members of the family all belong either to the genus 
Orbicula or to Crania. Species of both genera have lived 
during every epoch in the world’s history, and maintained 
a striking resemblance to each other. Those of the former 
genus are wonderfully preserved, even in the very oldest 
fossiliferous strata, in consequence of the horny texture of 
their valves. At present, half a dozen Orbicule and half 
as many Crania, are the living representatives of the tribe, 
which, like other families of Brachiopoda, held a much 
more important position anciently in the population of the 
seas, than it holds now. None of the shells have true 
hinges or cardinal ligaments. 

Dr. Carpenter describes the microscopic structure of the 
shell of Orbicula as closely resembling that of Lingula. 
He states, that it is almost entirely composed of lamin 
of horny matter, which are perforated by minute tubuli, 


CRANIA. 365 


closely resembling those of ivory in size and arrangement, 
and passing obliquely through the lamine. Near the 
margin of the shell these tubuli may be seen lying nearly 
parallel to the surface.* 


CRANIA, Rerz. 


Shell inequivalve, equilateral, orbicular ; the upper valve 
patelliform, with an eccentric summit ; wrinkled, smooth, or 
with radiating ribs or striz (not sculptured in our native 
species) ; under-valve flat, imperforate, adherent by its 
entire external surface, fixed to various substances. No 
hinge or ligament. Four muscular impressions in each 
valve. 

Animal with two large horizontal cirrhated buccal 
appendages, each forming a short spiral arm, curved 
inwards, free and unprovided with any skeleton. 

This view of their relations is, however, on the point 
of being combated by the celebrated Danish naturalist, 
Professor Steenstrup, whose researches have, we believe, 
led him to the unexpected conclusion that the Hippurites 
and their allies are really related to tubicolous Annelida. 

This very curious genus is better known in the fossil 
than in the recent state, though it is probable that all the 
fossil Crania are improperly associated in the same generic 
group. Those which have produced, and have free under- 
valves, should form a separate section, and in them we see 
a passage towards Calceola on the one hand, and the 
Rudiste on the other, which would go far towards esta- 
blishing the brachiopodous nature of those curious fossils. 


* Carpenter, Brit. Assoc, Rep. 1844. 


366 CRANIADA. 


C. anomana, Miiller. 


Plate LVI. fig. 7 and 8 ; (animal) plate U. fig. 2 (as Norvegica). 


Patella anomala, MLLER, Zool. Danica, pl. 6. 
,,  distorta, Monr. Trans. Linn. Soc. vol. xi. p. 195, pl. 13, f. 5. —FLEMING, 
Edinb. Encyclop. vol. vii. p. 65, pl. 204, f. 4. 
Anomia turbinata, Ditiw. Recent Shells, vol. i. p. 286 (in part).—Index Testa- 
ceolog. pl. 11, f. 2. 
Discina Ostreoides, Turron, Dithyra Brit. p. 237. 
Crania personata, SowERBY, Trans. Linn, Soc. vol. xiii. p. 471, pl. 26, f. 3. — 
Croucu, Introd. Lam. Conch. pl. 13, f. 3 (probably). 
Criopus anomalus, FLEMING, Philosoph, Zool. vol. ii. p. 499; Brit. Animals, 
p. 377. 
Crania rostrata, Brit. Marine Conch. p. 125. 
Orbicula Norvegica, Poriez and Micuavup, Galerie de Douai, Moll. vol. ii. pl. 43, 
f. 1? — Brown, IIlust. Conch. G. B. p. 69, pl. 22, f. 9, 
and pl. 20, f. 21, 22. 
Crania A SowErsy, Thesaur. Conch. vol. i. p. 368, pl. 73, f. 15, 16, 17. 
»  anomala, LovEN, Index Moll. Scandinavie, p. 29. 


The upper or free valve of this interesting shell is de- 
pressed, conical, or umbrella-shaped, rather thin, or but 
moderately solid, either of a rufous brown, reddish chocolate, 
or paler or darker liver-colour, or else broadly rayed, with 
those hues upon a paler ground of the same tint, and is 
devoid of all sculpture beyond the mere wrinkles of increase. 
The shape is suborbicular, with a tendency to become sub- 
quadrate ; the vertex is acute, submarginal in most ex- 
amples, but in individuals which have been uninterruptedly 
developed, subcentral (but not quite in the middle); there 
is generally also a slight indentation or straitening of that 
portion of the margin which is the nearer to it, or else of 
that portion immediately opposite the former. Internally 
the surface is more or less punctated or shagreened ; the 
upper or eye-like scars of the mask are decidedly large ; 
the lower or imaginary beardlike ones are still larger, 
almost, if not quite, united to each other, and each divided 


CRANIA. 367 


by a few somewhat radiating obscure groove-like inden- 
tations. The lower or attached valve, which is a mere 
coating of shelly matter, is not larger than the other, but, 
on the contrary, is entirely concealed by it. Its lower 
sears are large, ovate, and somewhat angular above ; the 
upper ones are separate, ovate, and almost linked together 
in the middle; the rostellum or noselike intermediate 
portion is obtuse; the disk palmato-radiated; the margin 
thickened and somewhat scabrous. The diameter varies 
from half an inch to eight lines. 

The animal was first figured and noticed by Otho 
Frederic Miller, who well styled it, “ Vermis singularis- 
simus,” yet persisted in regarding it as an anomalous form 
of Patella. ‘The arms are extended horizontally, each 
forming a rather short, graceful, plume-like curve, the 
fringed side being outermost. The fringes are long and 
rather stiff, and can be extended slightly beyond the shell. 
They are of a fleshy-white colour. When the upper valve 
is removed, the fringed arms are seen lodged in it. On 
the under-valve the ramifying ovaries, which are of a 
tawny hue, remain. 

This curious bivalve was first added to the British lists 
by Dr. Fleming, who found it adhering to stones, from 
deep water in Zetland; since then it has been taken 
abundantly in several localities, chiefly on the west coast 
of Scotland. Off Arran in twenty fathoms (Smith) ; 
Loch Fyne in thirty to eighty fathoms, plentiful, on 
stones; off Mull in twenty and ninety fathoms; off 
Lismore in from twenty to thirty fathoms; off Arma- 
dale in eighteen fathoms ; off Copenhaw-head, Skye, in 
forty fathoms; on the Ling banks off Zetland in fifty 
fathoms (M‘Andrew and EH. F.); Loch Alsh, Loch 
Carron, Ullapool, Oban, east of Lerwick, in forty fathoms 


368 CRANIADEA. 


(Jeffreys). In Ireland it has been taken off Youghal by 
R. Ball, and off Cork by Humphreys. 
It ranges throughout the Scandinavian seas. 


SPURIOUS. 


Orsicuta striata, Sowerby. 


Discina Ostreoides, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 297 (no descrip- 
tion).—Brit. Marine Conch. p. 125. 

Orbicula Norvegica, SowERBY (not Lam.), Trans. Linn. Soe. vol. xiii. p. 468, pl. 
26, f. 2.—SoweErsBy, Genera of Shells, Orbicula, f. 3, 4, 
5.—REEVE, Conch. Systemat. pl. 129, f. 3, 4, 5. 

Discina x Croucu, Introd. Lam. Conch. pl. 13, f. 2. 

Orbicula striata, SowERBY, Thesaur. Conch. vol. i. p. 366, pl. 73, f. 8. 


Locality unknown ; found in ballast used to mend roads near 
London. Described by Fleming in his “ British Animals,” but 
avowedly as a very doubtful native. 


369 


SUPPLEMENTARY NOTES ON THE 
ACEPHALA. 


Durie the publication of our account of the British species of 
this class of Mollusks, some new matter of much interest has come 
to hand, and descriptions of several new tunicated forms made 
public. Instead of reserving them for the general appendix at the 
close of the entire work, we think it best to print such notes as are 
likely to be immediately useful in this place, at the close of the 
Acephala, and, at the same time, to correct some errors into which 
we had inadvertently fallen. Additional memoranda on species 
we shall reserve for our text explanatory of the plates, to be given 
at the close of the work. 


TUNICATA. 


Although this order offers a rich harvest to the explorer of our 
shores and seas, little more has been published in addition to the 
account we gave in our first two numbers. In the valuable 
catalogue of the “Marine Mollusca of Northumberland and 
Durham,” by Mr. Alder, that able naturalist, in conjunction with 
Mr. Albany Hancock, has given descriptions of several new, 
simple and compound Ascidians, which we here transcribe. 


SIDNYUM TURBINATUM. 


“ A species, which we had always taken to be this, is not rare on 
our coast, but it differs from that figured in Forbes and Hanley’s 
‘British Mollusca.’ It is inversely conical, sometimes adhering 
by a narrow base, and is of an orange-red colour, with the animals 
vertically and concentrically arranged : their branchial apertures 
are eight-cleft. The masses are of different sizes, from a quarter 
to half an inch high, erect, and frequently clustered.”—ALp. 
Cat. p. 109. 


VO. I0. 3B 


370 SUPPLEMENTARY NOTES 


Borryiius rusens, Alder and Hancock. 


“General envelope thin and transparent, dull brown, with 
numerous opaque yellow granules. Individuals forming circles, 
or stars, of from four to fifteen, generally averaging seven or 
eight ; their colour is various shades of red, from reddish-yellow 
to dark brick-red : there is usually a circle of dark red round the 
branchial aperture, and at a little distance from it, and a streak 
of the same down the centre of the thorax ; the remainder of the 
body is pale red or yellowish, thickly sprinkled with opaque 
yellowish-white spots. General aperture of each system, rather 
small. The stars are smaller, and not so closely set as in the last 
species. 

“ On the under side of stones between tide-marks, Cullercoats, 
frequent. 

“ We have occasionally seen the central red line of the body so 
much diminished that it leaves little more than a spot, and in 
that case the species might be taken for the last; but it may 
always be known from it by the thinness of the general envelope, 
and the more variegated reddish colour of the inclosed animals.” 
—Aup. Cat. p. 110. 


B. virescens, Alder and Hancock. 


“General envelope moderately thick, olive-brown coloured, 
sprinkled with yellow spots. Individuals forming circles of from 
six to twelve. Colour grass-green, varying to greenish yellow, 
and occasionally to pale grey ; the colour is in most cases con- 
fined to the lower part of the animal, the upper portion being so 
nearly the colour of the envelope as to be with difficulty dis- 
tinguished from it. Branchial apertures large, with a faint 
red margin ; the tentacular filaments very conspicuous within 
them, of a pale yellowish colour. When magnified, the colour 
of the body is shown to be formed of a copious sprinkling 
of opaque spots, mostly confined, as before stated, to the lower 
part of the animal, but sometimes extending round the disc. 
Common central apertures largish, margined with red. Not 
uncommon on the under side of stones within tide-marks, along 
with the last. The arrangement of the markings distinguishes it 
from the B. smaragdus of Milne-Edwards.”—A.p. Cat. p. 111. 


ON THE ACEPHALA. Bil 


B. castaneus, Alder and Hancock. 


“ General envelope very thin and pellucid, with a few scattered 
brown marks and black punctures on the margin. Individuals 
large, placed in irregular circles of from six to eight, of a chestnut 
colour, irregularly blotched with purple brown, and minutely 
sprinkled with opaque white. Branchial aperture small, general 
aperture moderate. Stars rather far apart, and surrounded with 
a few large opaque yellowish-white globular bodies. 

“On the under side of stones, in pools, between tide-marks, 
Cullercoats, rare. 

“The envelope of this species is thinner than in any other we 
are acquainted with, and, when removed from the stone, is 
extremely flaccid. The patches are large, being sometimes five 
inches across.” —Aup. Cat. p. 111. 


Borryiiomwes rapiata, Alder and Hancock. 


“General envelope yellowish-olive, with yellow granules. 
Individuals rather small, broadly pear-shaped, pale ochreous 
yellow or straw-colour, spotted with white, and having a paler 
rim round the branchial aperture, with rays diverging from 
it and uniting into a dise beyond, giving a petaloid or wheel-like 
appearance to it. A darkish line runs down the thorax. The 
systems are arranged in much shorter and more compact folds 
than in the last ; some parts occasionally assuming the appear- 
ance of a circular arrangement. The common apertures are 
usually situated at no great distance from each other. 

“On the under side of stones, among the rocks at Cullercoats 
and Whitley, frequent. 

“The smaller size, more varied markings, and shorter and 
more rounded convolutions, distinguish this species from the last. 
The wheel-like markings ally it to the B. rotifera of Milne- 
Edwards, but the colour never approaches to red, and the folds of 
B. rotifera appear more elongated than in ours. In this respect 
our species approaches more nearly to the arrangement of B, 
albicans.” —Aup, Cat. p. 112. 


Bt SUPPLEMENTARY NOTES 


B. ramuxrosa, Alder and Hancock. 


“General envelope colourless, pellucid, with a few pale yellow 
spots on the margin. Systems of individuals winding, much 


involved ; and having a broad cream-coloured belt down the . 


centre, following the sinuations. Animals of an obscure brownish 
yellow, with the lower half pale opaque yellow. 

“On the underside of stones, in pools, between tide-marks, at 
Cullercoats, rare. A. H. 

“ This species, which is in patches of upwards of an inch and a 
quarter across, is at once distinguished from B. Leachii by the 
opaque belt of cream-colour that passes along the centre of the 
various systems of animals.’—Aup. Cat. p. 113. 


Ascipia sorpipa, Alder and Hancock. 


“Body ovate ; of a dull semi-transparent yellowish white ; 
nearly smooth, but coarse and with an uneven surface ; attached 
by a narrow base. Apertures terminal and not far apart, papillose 
or very slightly tubular, more or less echinated or tuberculated ; 
the branchial aperture eight-cleft, the anal six-cleft, with a red 
eye-spot at the base of each division. Outer tunic transparent, 
vitreous and colourless, rather tough, with very little power of 
contraction or expansion. Inner tunic about one-third less than 
the outer one, soft yellowish, and generally very much blotted and 
spotted with crimson, towards the upper end. Branchial sae, 
with small even reticulations a little thickened at the intersec- 
tions. Circle of tentacular filaments simple and slender. Length 
about two inches; breadth an inch and a quarter; but very 
variable in size. 

“This is one of the commonest Ascidiw brought in on the 
fishing-lines at Cullercoats. It is usually attached to corallines ; 
occasionally to shells and other substances. In its young state 
it is gregarious, and is found in clusters on Genicularia loriculata, 
and sometimes inside dead bivalve shells. It is then very trans- 
parent and hyaline ; Modiola marmorata is occasionally found im- 
bedded in the older individuals. This species may be the Ascidia 
prunum of Macgillivray, but not of Miiller..—Aup. Cat. p. 106. 


ON THE ACEPHALA. dita 


A. atpipa, Alder and Hancock. 


“Body ovate, white, transparent, and slightly tuberculated. 
Attached laterally by a narrow base to small sea-weeds. Branchial 
aperture lateral or subterminal, large but not very prominent, the 
margin divided into eight points with intermediate red ocelli. 
Anal aperture a little distant from the other, and nearly half 
way down the body, on the upper side; largish, and little 
prominent, with six red ocelli. Outer tunic hyaline and colour- 
less, covered with distant small tubercles. Inner tunic trans- 
parent white with bluish lines on the upper part ; below, opaque 
white slightly spotted with yellow. There is a large opaque 
white spot on the ganglionic prominence between the apertures, 
near which are a few small reddish marks. Length, half an inch ; 
breadth, one-third less. On small sea-weeds brought in by the 
trawl-boats, with the last. Not uncommon.”—Atp. Cat. p. 107. 


A. pepressa, Alder and Hancock. 


“ Body oblong ovate, very much depressed, pale green ; attached 
laterally through its entire extent by a distinct expansion or disc, 
surrounding the whole. Apertures distant ; the branchial one 
terminal, not much produced, and divided into eight points, with 
intermediate red ocelli ; anal aperture about two-thirds down the 
body on the left side, with six segments and intermediate ocelli. 
Outer tunic transparent, granulated or tuberculated on the upper 
surface, the granules sometimes a little incrusted with brown ; 
under or attached side smooth and very thin, Inner tunic one- 
third less than the outer, yellowish green, of a deeper colour and 
sometimes inclining to orange in the lower part. The intestine 
is often very conspicuous, forming a dark sigmoid coil, but this is 
more or less the case in all the transparent species. Branchial 
sac finely reticulated, with tubercles at the intersections. Length 
nearly an inch. Common; attached to the underside of stones, 
among the rocks at Cullercoats and Whitley. 

“This species comes very near to the Ascidia orbicularis of 
Miller (Zool. Dan. t. 79, p. 1, 2), but differs in the position of 
the apertures, which in that species are represented to be rather 


Bye! SUPPLEMENTARY NOTES 


near together at the anterior end, while in ours they are widely 
separated.”—ALp. Cat. p. 107. 


A. exuiptica, Alder and Hancock. 


“ Body elliptical, a little convex on the upper side, and flat 
beneath, of a dull and sub-opaque brownish or yellowish white ; 
attached through its whole length by a rather inconspicuous dise. 
Branchial aperture not quite terminal, at the anterior end papillose, 
very little elevated, and divided into eight tubercular segments. 
Anal aperture situated a little below the branchial one, on the 
left side, not prominent, with six tubercles. Outer tunic tough, 
sub-opaque, nearly smooth but rather coarse ; inner tunic opaque 
white or flesh-coloured, with a few spots of red between the 
apertures. The red ocelli of the apertures, which are scarcely 
visible outside, are distinct in the inner tunic. Branchial sac 
reticulated with slender papillz at the intersections of the larger 
meshes. Length, three-quarters of an inch; breadth, about one- 
third less. Attached to the under side of stones within tide- 
marks. Cullercoats. Not common.”—Aup. Cat. p. 107. 


A. prtiucipa, Alder and Hancock. 


“ Body depressed, hyaline, subtriangular, attached laterally by 
a broad disc. Branchial aperture terminal, wide and tubular, 
divided into eight segments with red ocelli. Anal aperture 
situated a little below it on the left side, tubular and curved 
inwards towards the upper surface, with six ocellated segments. 
Outer tunic smooth, coriaceous, colourless and perfectly trans- 
parent. Inner tunic not above one-half the size of the outer one, 
opaque yellowish white, inclined to red on the lower part. Length 
half an inch. Under stones within tide-marks. Cullercoats, 
rare.”—A.p. Cat. p. 108. 


Moteura arenosa, Alder and Hancock. 


The species of Molgula which we have described and figured as 
the Ascidia tubularis of the “Zoologia Danica,” is considered 
distinct by Alder and Hancock, who have given it the above 
very appropriate appellation. 


ON THE ACEPIIALA. 375 


Cynruia corracea, Alder and Hancock. 


“Body elongated and cylindrical when extended, nearly 
hemispherical when contracted, of a pale brownish colour, at- 
tached to shells, etc. by a broad base, equalling the diameter of 
the body. Apertures terminal, approximating, tubular, nearly 
equal in size, pale, with a faint line of red round the margins. 
Outer tunic rough, coriaceous, transversely wrinkled and longi- 
tudinally furrowed, covered with minute granules. Inner tunic 
thin, white, sometimes spotted with brown. Ovaries large and 
white, lining the tunic with cylindrical convolutions. Branchial 
sac thin, with about ten longitudinal folds, and finely reticulated ; 
the longitudinal fibres strongest. Length nearly an inch ; breadth 
half an inch. From the fishing-boats at Cullercoats with the 
last, but less common. 

“This species differs from the preceding in having both the 
apertures terminal, and placed near together, as well as in the 
minute granulations of the surface. It is capable of greater 
contraction and elongation than most of the other species, and in 
the two states, might be taken for different animals. It has 
sometimes small corallines attached, but we have not observed 
any Modiole imbedded in its skin,” ——A.p. Cat. p. 102. 

In our account of Salpa, Dr. Fleming is stated to have 
observed great numbers on the coast of Caithness in the spring of 
1821. It should have been “on the north coast of Sutherland- 
shire and the Hebrides,” in autumn. 


LAMELLIBRANCHIATA. 


In our plates of the animals of bivalves, there are three figures 
which are seriously in error. One is Cyprina Islandica, which, 
by an oversight of the engraver, is represented with the beak of 
the shell towards the siphonal extremity, instead of from it(see 
plate M. fig. 4.) —The second is Z'urtonia purpurea (plate O. f. 1), 
which should have the siphon projecting from the long end of 
the shell instead of the short one: of this animal a fresh figure 
will be given.—The third is Xylophaga dorsalis, respecting which 
curious mollusk we have received new and very important infor- 


376 SUPPLEMENTARY NOTES. 


mation and sketches of the animal from Mr. Cocks, of Falmouth. 
According to that excellent observer, the siphon is single and the 
anal aperture opens about one-third from the base. Crested 
ridges with pectinated edges, run from the root of the siphon to 
its extremity. The natural length of the siphon of one kept 
alive by Mr. Cocks, was one inch and a quarter. We shall give 
afresh figure. In the body of the work, as well as upon the 
plate itself, the representation of that variety of Astarte Dan- 
monrensis, which has a red interior (xxx. f. 5), is erroneously 
assigned to A. triangularis. 

In a note at page 45 of vol. i., the genus Clausina of Jeffreys 
is stated to have been arranged by Mr. Gray among his Tellinide. 
This is a mistake ; Mr. Gray placed it in his Lasiade and next to 
Montacuta ; a position by no means unnatural. In our descrip- 
tions of the MZontacute, the longer side of the shell is, by an over- 
sight, described as the posterior extremity, which is contrary to the 
more correct statement put forward in the account of the animals. 
Since the commencement of our work, several important papers 
have been published bearing on this part of our subject, such as 
the memoir of M. de Quatrefages on Teredo, the controversy on 
Kellia between Mr. Alder and Mr. Clark, &c. ; but on these and 
other points we reserve our notes until the conclusion of the 
work, 


pierer- 


377 


PTEROPODA. 


In warmer seas than those which encircle our islands, 
the surface of the water, when the weather is calm and the 
sun is shining, glistens with glassy needles or shelly bub- 
bles. These, upon closer examination, prove to belong to 
curious mollusks, which, instead of creeping over submarine 
rocks and weeds, or burying in the soft mud and sand of 
the sea-bed, aspire to a gayer and more sportive life, and 
play the part of Neptune’s bees and butterflies. From our 
less congenial waves they are almost altogether absent; 
only a few stragglers, and those, with one exception, of 
microscopic dimensions, have met even the scrutinizing eyes 
of practised naturalists. 

These animals are mollusks of the group to which 
Cuvier gave the name of Pteropoda, so stylmg them on 
account of the wing-like lobes which form their organs of 
motion, and which appear really to be expansions of the 
organs regarded as a foot among the true sea-snails. Their 
organization is, however, so peculiar that zoologists have 
differed materially respecting their true position in the 
animal series, some, as Cuvier and Rang, placing them 
high up among the mollusca, intermediate between the 
sea-snails and the cuttle-fishes; others, as Lamarck, con- 
sidering them as intermediate between the sea-snails and 
bivalves, and others placing them even below the acephala. 
A few high-standing names have maintained that they 

VOL. I. 3C 


378 PTEROPODA. 


have no claim to a higher distinction than that of forming 
a tribe of Gasteropods allied to Bulla and Aplysia, and 
this opinion, which was advocated by De Blainville, has 
recently been supported by Souleyet, a naturalist who has 
had abundant opportunities for the study of them, and who 
has done much to elucidate their history.* 

This is not the place to discuss the zoological status of 
a group of animals playing so unimportant a part in the 
British Fauna as the Pteropods do. Suffice it to say that 
on account of their inferiority of organisation, and at the 
same time the striking analogy they present with the 
embryonic forms of the majority of marine gasteropoda, to 
which in many of their features they have close relations 
of affinity, we are induced to assign to them in this work 
the position of an independent group superior to the 
Acephala and below the Gasteropoda. 

The Pteropods are free and floating mollusca, swimming 
by means of the wing-like fins already alluded to. Some 
of them have shells and some are unprovided with such 
coverings; the latter have a more or less distinct head, 
and a rudimentary foot, which are denied to the former. 
The respiratory organs are external in the naked species, 
enclosed in a cavity in those with shells. They have a 
single heart. The viscera of their digestive system vary in 
the different genera: some are provided with curiously 
armed gizzards. The sexes are united. Their organs of 
Sense are very rudimentary; the presence of otolitic ve- 
sicles has been demonstrated by Souleyet. Their nervous 
system is less highly developed than that of the Gaster- 
opods. 


* See an abstract of M. Souleyet’s Researches in the “* Comptes Rendus ” 
for October, 1843. 


HYALEA. 379 


Our few British species are all members of the shelled 
division of the order, and belong to two different families, 
viz., the Hyatrap# characterised by their corneous sheath- 
like, more or less triangular shells, and the Limacinap.®, 
whose bodies are enveloped in regularly spiral shells, re- 
minding us closely of those of many Gasteropoda. 


HYALEA, F&russac. 


Shell thin, corneous or glassy, smooth or furrowed, more 
or less globular, with a spine or angle at each side, and 
one forming its posterior termination; sides split, mouth 
transverse, anterior, one of the lips overlapping. 

Animal with a globular body, having two wing-like 
lateral expansions which are projected from the slits at the 
sides of the shell, and a broad expanded two-winged 
natatory disk, extending on each side of the anterior 
extremity. Head not distinct. Branchize lodged in a 
special cavity. No operculum. 

The Hyalee are oceanic, and on account of their size and 
colour are easily distinguishable in the water, especially 
when the animal expands its swimmers and fins. It is by 
no means improbable that more than one species may 
occasionally visit the western shores of Britain, and those 
naturalists who may meet with the fleets of Janthine and 
Velelle which are occasionally wafted on shore in the west 
of Ireland, the Hebrides, and the south-west of England, 
would do well to search carefully among the débris, lest 
Hyalee and allied Pteropods may accompany floating ani- 
mals which are their constant companions in seas more to 


the south. 


380 PTEROPODA. 


H. rrisprnosa, Lesueur. 


Plate U, fig. 3. 


Davita, Cat. Cabinet, vol. i. pl. 20, f. e, ? 
CueEmn. Conch. Cab. vol. viii. p. 65, vignette 13, f. c. d. 
Hyalea trispinosa, Lesuzur, MSS. in Buarnv. Dict. Sc. Nat. vol. xxii. p. 82.— 
THompson, Ann. Nat. Hist. vol. v. p. 13; Report Brit. 
Assoc. 1843, p. 249.—Quoy and Gaym. Voy. Astrol. vol. 
vii. p. 378, pl. 27, f. 17, 18, 19.—Dzxsu. Encycl. Méthod. 
Vers, vol. ii. pt. 2, p. 310; Lam. Anim. s. Vert. vol. vii. 
p. 417, 421.—Cuv. Régne Anim. (ed. Griffith) pl. 3, f. 7. 
— D’Orzic. Moll. Cuba, p. 81. — Puivierr, Moll. Sicil. 
WOleiiienp s/s 
» mucronata, Yuoy and Gaym. Ann. Sc. Nat. vol. x. p. 23], pl. 8, 13, f. 
1.2! (fide Desh.) 
»  triacantha, GuipoTTI, in Bronn Ital. p. 85 (fide Philippi), fossil. 
»»  depressa, Bivona, teste Philippi, Moll. Sicil. vol. i. p. 101, pl. 6,f. 19, 
fossil. 


Hyales a trois pointes, CHENU, Traité Elem. Conch. p. 125, f. 403, 404. 


The only indigenous example of this fragile shell haying 
inadvertently been crushed, our description has necessarily 
been derived from foreign examples, one of which was the 
specimen sent to us by Mr. Robert Ball as identical with 
the individual, from whose discovery by himself, the species 
has been introduced into the British Fauna. 

The shell is of a more or less transparent white, partially 
stained with brown or vinous red, especially near the lips, 
and at the commencement of the tail. It is depressed, 
straight (not curved), and kite-shaped: the anterior extre- 
mity, or the portion above the short, but very acute, lateral 
spines, one of which runs out nearly at right angles, or with 
a slight descending inclination, to the body on each side of 
it, is much shorter than the posterior end; the latter is 
produced into a very long and slender straight caudal spine, 
which, however, is very rarely procured in an unbroken 
state. The labial aperture is short, narrow, and semi- 


elliptic, the marginal fissure, which extends to the tips of 


HYALEA. 381 


the lateral spines is delicately linear; both lips are briefly 
and abruptly reflected. 

The upper and lower surfaces are of nearly equal con- 
vexity, and are both of them, more frequently than other- 
wise, devoid of well marked concentric strie. The former 
projects semicircularly, but only slightly, beyond the 
straightish anterior or labial edge of the latter, and is 
adorned with a broad rounded central fold, which is ge- 
nerally, if not always, subdivided in front into three smaller 
ones, flanked on each side with a strong but narrower fold, 
which leaves a flattish triangular space between it and the 
termination of the lateral spine. Merely a slight fold 
adjacent to each lateral spine is observable upon the lower 
superficies. The posterior edges, previous to the com- 
mencement of the caudal spine, which when perfect is at 
least equal in length to the space from its origin to the 
lateral aculeations, and tapers with extreme slowness, run 
towards each other subrectilinearly and nearly at right 
angles. The specimens we have described from, measure 
at least five lines in length, and three and a half in breadth 
from prickle to prickle. 

The circumstances under which this shell has been taken 
are as follows. About the year 1820 a large mast floated 
into Youghal, covered with Anatifa levis, and perforated 
by Teredines. From the water in which the sawn-off end 
had been Javed, Mr. Robert Ball of Dublin obtained a 
Spirula and a Hyalea ; the latter shell was still filled 
with animal matter, although life was extinct in the Pter- 
opod. From the roving habits of the genus, it is by no 
means improbable that many more examples have at times 
been wafted upon our shores, but perished through their 


extreme fragility, before attracting observation. 


382 PTEROPODA. 


SPIRIALIS. Eypoux anp SouLEyerT. 


Shell thin, transparent, of several spiral whorls, coiled 
sinistrally, spire elevated or depressed, surface smooth or 
(in some foreign species) reticulated, mouth angulated be- 
low or canaliculated, sometimes prolonged into a spine-like 
curved beak. 

Animal elongated spiral, head not distinct; two fin-like 
expansions united at their base by an intermediate lobe 
bearing an operculum ; branchize in a cavity formed by the 
mantle. Operculum vitreous, very thin and transparent, 
of few whorls. 

This genus was constituted in 1840 * by the naturalists 
attached to the exploring ship Bonite, for some curious 
minute oceanic Pteropods with which they had met during 
their voyage. They were the first to meet with and de- 
scribe the animal inhabitants of certain little sinistral fusi- 
form shells, which had been placed in Atlanta by Alcide 
@Orbigny, but which had evidently no affinity with the 
Nucleobranchiata. Long before, one of these from Rimini 
in Italy had attracted the notice of Spengler and been 
figured by Chemnitz,+ and another had been described and 
figured as a reversed form of Fusus by Dr. Fleming. In 
1842 one of the authors of this work founded a genus under 
the name of Prracte for a remarkable minute shell dredged 
at great depths in the AXgean, and at the Cork meeting of 
the British Association referred Dr. Fleming’s Fusus retro- 
versus to the same genus, giving reasons why they should 
be considered Pteropods, unaware of their true position in 
that group having been already discovered and published 
by the French naturalists already cited. About the same 


* Revue Zoologique Soc. Cuv. 1840, p. 235. 
oO 


+ Chemnitz, Conch. Cab. vol. ix. pl. 113. 


SPIRIALIS. 383 


time Dr. Philippi constituted his genus Scaa for a shell 
very similar to the Adgean Peracle physoides. 

MM. Eydoux and Souleyet have described six species 
of this genus, and of all these have examined the animals. 
In all they found them furnished with a pair of elongated 
swimmers, rounded and not bilobed at their extremities, 
and an intermediate lobe of semicircular shape at the union 
of which with the other two lobes the mouth, furnished with 
two little labial elevations, is situated. The opening of the 
vent was seen at the right side of the mantle; the repro- 
ductive organs were not clearly made out. We have 
copied (in our Plate U, fig. 4) one of the figures of these 
curious animals given in the Atlas to the voyage of the 
Bonite, in the hope of directing the attention of British 
naturalists, who may be so fortunate as to meet with living 
individuals of our native species, to their generic pecu- 
liarities.* 

“These Pteropods,” say the authors cited, “are distri- 
buted through all seas, and we have equally met them in 
the Atlantic, the Indian, and the Pacific oceans, and in the 
Chinese seas.” 

Spirialis is evidently nearly allied to the old genus 
Limacina. 


* Tn the plate this figure is given under the name of Peracle, a generic appel- 
lation, which, for reasons stated above, must give way to Sprialis. We had 
been misled by the date of the plates in the yoyage of the Bonite. 


384 PTEROPODA. 


S. Fiemincu, Forbes. 


With the body whorl very ventricose; the spire of four whorls, 
but not forming half the length of the shell. 


Plate LVII. fig. 4, 5. 


CueEmn. Conch. Cab. vol. ix. pt. 1, p. 129, pl. 113, f. 972, 973 (2). 

Fusus retroversus, FLEMING, Mem. Wern. Soc. vol. iv. p. 498, pl. 15, f. 2. ; 
British Animals, p. 3849 ; Treatise on Mollusc. Animals (from 
Encycl. Brit.), pl. 12, f. 45.—British Marine Conchology, 
p. 201. 

Scea stenogyra, Puruirri, Moll. Sicil. vol. ii. p. 164, pl. 25, f. 20 (probably). 

Peracle Flemingii, Forses in Brit. Assoc. Report, for 1648, p. 249.—Jzrrr. 
Ann, Nat. H. vol. xx. p. 16. 


This very minute shell—it is not very much larger than 
an ordinary pin’s head—was discovered by Dr. Fleming, 
and, from its striking resemblance to many species of the 
genus, was considered by him as a reversed Fusus. It is 
very thin, transparent, shining, smooth, of a clear horn 
colour, and more or less iridescent when living, of a 
porcelain white when dead. Its general outline is not 
unlike that of a boy’s peg-top. The body-whorl is very 
ventricose, and short in proportion to its breadth; it 
exceeds in vertical length the entire pyramidal spire, 
which is composed of four very narrow, well defined 
whorls, that terminate in an extremely small, but blunt 
or even depressed point. These volutions are rounded, 
but are so far subangulately flattened above, as to appear 
obtusely subscalariform. The base is rounded, but is still 
a little depressed, that is to say, the attenuation is rather 
abrupt. The mouth is narrow and ear-shaped; it occupies 
at least half the length of the shell, but is not equal to 
half the basal diameter; it is attenuated and effuse at the 
bottom, and not truncated, as it seems in our engraving. 


9 


SPIRIALIS. 385 


The outer lip is simple, arcuated above, and subrectilinear 
below ; the inner one is straightish, and by its reflection 
conceals the umbilical chink. 

The Spirialis Flemingit was met with by its discoverer 
among shell sand collected in Noss Island, Zetland, after a 
storm in the spring of 1809. He rightly observed that it 
was not the fry of a large shell. In 1840 more specimens 
were found by Mr. Hyndman among shell sand collected 
by Mrs. Hancock at Bundoran on the coast of Donegal. 
In 1848 Mr. M‘Andrew dredged dead specimens in sixty 
fathoms of water, fifteen miles from Mizen Head, south of 
Ireland. It was afterwards taken off Arran in Ireland, in 
Skye and Zetland, and at Guernsey, by Mr. Barlee. 

The Spirialis ventricosa of Kydoux and Souleyet is 


nearly allied to our species. 


S. MacAnorer, Forbes and Hanley. 


Turreted-fusiform, the body whorl not equal in length to the 


spire. 
Plate LVII. fig. 6, 7. 


? 2 Turbo lunaris, GMELIN, Syst. Nat. p. 3587, from Chemn. Conch. Cab. vol. 
ix, p. 128, pl. 113, f. 971 (broken ?). 

This tiny shell is very minute, thin, and pellucid, and of 
a horn colour. The surface of the whorls is quite smooth 
and shining. The general shape is lanceolate and less than 
one half of the length is occupied by the body-whorl, which 
is not swollen out as in the last species, but gently tumid. 
The spire is formed of five whorls that very gradually 
decrease; they are slightly tumid, and rather narrow. 
The terminal whorl forms an obtuse apex. The mouth is 
somewhat elliptical, and rather narrow ; it terminates below 
in a short canal, which is slightly bent, but not mucro- 
nated. 

VOL. II. 3 D 


386 PTEROPODA. 


We owe the discovery of this curious addition to our 
Fauna, to Mr. M‘Andrew who, in June 1848, dredged 
several specimens along with the preceding species in sixty 
fathoms of water, fifteen miles to the south of Mizen Head, 
south of Ireland. 

Its nearest ally appears to be the Spirialis Bulimoides of 
D’Orbigny. 


S. Jerrreysu, Forbes and Hanley. 


Shell subdiscoid, spire much depressed, lip very acute, mu- 
cronated. 


Plate LVII. fig. 8. 


This curious shell is easily distinguished from its British 
congeners by its very much depressed spire. It is very 
minute, very thin, fragile, and transparent. There are 
three whorls, the outermost of which is large in proportion 
and gently rounded; the second is slightly elevated above 
it, and the third very slightly above the second, so that its 
termination forms a somewhat acute apex. The surface of 
the whorls is quite smooth. The mouth is elliptically ovate ; 
its outer lip is thin and gently curved; the inner terminates 
in an acute, rather short, canaliculated, somewhat curved 
cauda or mucro. 

The only specimen we have seen is contained in the 
cabinet of its discoverer, Mr. Gwyn Jeffreys, who found it 
on the shores of the British channel. It is nearly allied 
to the Spirialis rostralis of Kydoux and Souleyet, a species 
said by them to be very common in the ocean, and occur- 
ring in myriads. 


GASTEROPODA PROSOBRANCHIATA. 


Tue great majority of our marine univalve shells are 
the body-coverings of sea-snails which have the lower 
part of their bodies formed into a thickened creeping 
disk or foot, and their organs of respiration lodged, in 
the shape of comblike gills, in a vaulted pallial cavity ; 
except a few genera, which have these organs lining, as it 
were, the inner margin of the mantle. The shell is partly 
devoted to the protection of the gills and partly to that 
of other viscera. The heart is in most of them placed 
behind the gills. The sexes are distinct. In common 
with all other gasteropods which breathe by branchiz 
they affect in their larva state a form reminding us of 
the Pteropoda, being then furnished with broad ciliated 
fins springing from the sides of the head. Their shells, 
except in a few instances, are spiral, and the larve 
appear to be always furnished with spiral shells, what- 
ever shape these important appendages may eventually 
assume. . 

The term Prosobranchiata was proposed for these mol- 
lusks by Milne Edwards,* who constitutes of them his 
second order of Branchiferous Gasteropods. Availing 
ourselves of the views promulgated by that eminent zoolo- 
gist, respecting the classification of the Gasteropoda — 


* Sur la Classification Naturelle des Mollusques Gasteropodes, Annale 
des Sciences Naturelles for February, 1845, 


388 GASTEROPODA. 


views which seem to us a great advance on previous 
classification — we adopt this very natural section, pre- 
ferrmg, however, to regard it and the parallel section 
Opisthobranchiata as equivalents of the Gasteropoda Pul- 
monifera. 

The shells of Gasteropoda do not present those dissimi- 
larities of structure which render the microscopic study of 
bivalve shells so interesting of late years. They have been 
carefully investigated by Mr. Bowerbank,* and by Dr. 
Carpenter,f and had previously been inquired into by 
Mr. Gray. ‘They appear, for the most part, to be made 
up of three distinct layers, uniformly constituted, but alter- 
nating in disposition, Each layer is composed of plates, 
each of which is made up of parallel prismatic cells. Pa- 
tella, Chiton, and a few other genera, present slight excep- 
tions to the general rule. In the excellent memoir by 
Dr. Carpenter, just referred to, a full account of all that 
has been done on this subject may be found and studied 
with advantage. 


* Microscopical Society’s Transactions, vol. i. 
+ British Association Reports for 1847. 


389 


CHITONID. 


‘* Iv seems to me,” writes Milne Edwards in the short 
but valuable paper to which we have just referred, “ that 
the animal kingdom, taken as a whole, cannot be com- 
pared with a well-regulated army, where each brigade, 
each regiment, and each company, has well-defined limits, 
and where every soldier has his fixed place under the flag 
of his corps; to give a just notion of it, it might better 
be compared to the stellary system, where a multitude 
of stars are disseminated at unequal distances, and form, 
from distance to distance, by their presence in great 
number within limited spaces, groups more or less remark- 
able, about which we see other stars, isolated as it were 
in the heavens, and not making part of any great system. 
The analogues of these constellations, in zoology, constitute 
classes and orders, and in the voids between them we 
often find some species which differ as much from all 
these groups as they differ among themselves, but which, 
being few in number, are not permitted to assume the 
same rank in our classifications as types do which are 
rich in species.” 

These sentiments are offered as illustrative of the family 
before us, which is considered by Milne Edwards as even 
doubtfully belonging to the mollusca, and at nearest, as a 
satellite group of Gasteropoda having relations to the Pro- 
sobranchiata. 'The Chitons have, indeed, been zoological 


puzzles, though regarded by the majority of malacologists 


390 CHITONID. 


as members of their special province. Cuvier held them 
to be gasteropods closely allied to Patella with which 
genus he associated them to form his sub-order Cyclo- 
branches. De Blainville, on the other hand, considered 
them as more nearly allied to Annellida than to mollusca, 
and constituted a special group Polyplaxiphora for them. 
Unlike any other mollusks their bodies are protected by a 
series of shelly plates, resembling so many articulations. 
Their organs of reproduction are symmetrical, and re- 
peated on each side of the medial line, and there are 
a pair of sexual orifices. Their circulation is peculiar ; 
the heart resembles the dorsal vessel of an annellide. On 
the other hand, their respiratory organs are very similar 
to those of Patella, their digestive system and lingual 
apparatus remind us of those of Prosobranchiate mollusks, 
and the creeping disk is that of a true Gasteropod. As 
our knowledge stands at present, we prefer to regard them 
as an abnormal family of Prosobranchiata, and trust, 
before long, that some active observer resident by the 
coast will occupy himself with studying the development 
of the Chitons, and endeavour to ascertain the form they 
assume in their larval condition. Whoever does so will 
make an important discovery, and do more towards fixing 
the true position of these anomalous creatures than all 
cabinet examinations of them have yet enabled us to effect. 

In a recently published paper by Mr. J. E. Gray, the 
Chitons are maintained to be ‘normal Gasteropods, with 
a series of more or less rudimentary valves in front of the 
usual shell.” He considers the posterior terminal valve to 
be the homologue of the shell of Patella. 


CHITON. 391 


CHITON, Linnus. 


Shell oblong, composed of eight transverse plates, imbri- 
cating, variously ornamented on their surfaces; all lodged 
in a coriaceous mantle which forms an expanded, smooth, 
shagreened, wrinkled, granulated or spiny margin all 
round the body. 

Head of the animal obscurely defined, formed of a pro- 
boscis covered by a fleshy semicircular hood, no tentacles 
nor eyes; buccal mass with cartilaginous jaws, lingual rib- 
band long and linear, furnished with numerous transverse 
series of teeth, of which thwee in each series belong to the 
rachis, flanked on each side by a single large uncinated 
lateral tooth and a supplementary lateral, the last arising 
from among five polygonal flanking plates. Branchie 
forming a series of lamelle between the mantle and foot 
on each side; foot an oblong disk, rounded at each 
extremity. 

These curious mollusks constituted part of the ‘“ multi- 
valves” of old conchologists, and cannot be mistaken for 
members of any other genus or tribe. They are distri- 
buted all round the world, and the species are very 
numerous; often very curious and even beautiful. They 
live attached to rocks, stones, and shells; more rarely 
are they. found creeping on sand. They inhabit various 
depths of water; the majority of species are littoral or 
sublittoral, but a few range to great depths. From their 
fragility few traces of fossil species might be expected to 
be found; nevertheless, even as far back as the paleozoic 
epoch it would appear that Chitons were in being. 

We retain the genus Chiton in its original signification, 


deeming that, in the present imperfect state of our know- 


392 CHITONIDA. 


eldge of the soft parts of the several species, a separation of 
them into groups of generic value on account of slight dif- 
ferences in the shelly valves or ornamental surface of the 
mantle is, to say the least, premature. On such diffe- 
rences, however, good sections of the genus may be founded, 
and in such light we regard the divisions proposed by Mr. 
Gray and others. The most important contribution to 
a scientific knowledge of this genus is the recently pub- 
lished Memoir on Russian Chitons by our distinguished 
friend Dr. Middendorff, in which the species coming 
within range of his theme are investigated with a minute- 
ness and skill which cannot be praised too highly. This 
author is the first to notice a eharacteristic of the greatest 
value in the determination of species, but one which, being 
taken from the soft parts, has been neglected by concho- 
logists, viz. the number of branchial lamine and the 
extent occupied by them. Our own observations and 
those of Mr. Clark confirm, so far as they go, the value 
assigned to this character by Middendorff. A_ still more 
minute character—the form of the teeth, especially the 
central one, on the lingual ribband is also of great specific 
importance in Chiton, though difficult to observe. We 
owe the indication of it to the admirable researches of 
Professor Loven on the lingual teeth of Mollusca *— 
researches which will do much towards a right under- 
standing of the genera and families of Gasteropoda, and 
of which we intend fully to avail ourselves in the future 


portion of our work. 


* Ofversigt af Kongl. Vetenskaps-Academiens Forhandlingar. June, 1847. 


CHITON. 393 


C. rascicutaris, Linneus. 


Valves irregularly shagreened ; granules coarse and few; liga- 
mental border with tufts of bristles. 


Plate LIX. fig. 5. 


Chiton fascicularis, Linn. Syst. Nat. ed. 12, p. 1106 (probably).—PuLTEnry, 
Hutchins, Hist. Dorset, p. 25.—Monr. Test. Brit. p. 5 ; 
Suppl. pl. 27, f. 5.—Mar. and Rack. Trans. Linn. Soc. 
vol. viii. p. 21, pl. 1, f. 1.— Rack. Dorset Catalog. p. 25, 
pl. 1, f. 1.—Turr. Conch. Diction. p. 34, f. 9.—Lowe, 
Zool. Journ, vol. ii. p. 96.—FLEMine, Brit. Anim. p. 288. 
—Jounston, Berwick Nat. Club, vol. ii. p. 37 —Mac- 
GILLIV. Moll. Aberd. p. 183.— Brit. Marine Conch. p. 
128.—Brown, Illust. Conch. G. B. p. 65, pl. 21, f. 5, 8. 
—SPENGLER, Skriv. Nat. Selks. Kiobenhg. vol. iv. pt. 1, 
p- 81, in part. — Dinuw. Recent Shells, vol. i. p. 8 
(chiefly).—Lam. Anim. s, Vert. (ed. Desh.) vol. vii. p. 
492 (partly).—Sowxrsy, Conch. Ill. Chiton, spec. 1, f. 
87.—Conch. Man. f. 506 (magnif.). 

Chiton crinitus, PENNANT, Brit. Zool. ed. iv. vol. iv. p. 71, pl. 36, f. 1; copied 
in Chemnitz, Conch. Cab. vol. viii. vignette, p. 252.—Monr. 
Test, Brit. p. 4—Mar. and Rack. Trans. Linn. Soe. yol. viii. 
p- 20.— Tur. Conch. Diction. p. 35. — Brown, Illust. 
Conch. G. B. p. 65, pl. 21, f. 7—Woop, General Conch. p. 
23.— Ditiw. Recent Shells, vol. i. p.13.— Rerve, Conch. 
Iconic. vol. iv. Chiton, pl. 26, f. 176. 


As both this and diserepans inhabit the Mediterranean, 
it is uncertain, from the brief diagnosis in the “Systema 
Nature,” which of them was the Algerine species desig- 
nated fascicularis by the illustrious Linneus. In retaining 
that name for the present species, we follow the stream of 
preceding writers, being unwilling to disturb an accepted 
name without absolute necessity for so doing. The shape 
is elongated or produced oblong, and the back, which is 
more or less carinated, is depressed in the more typical 
examples. The posterior edge of the valves is beaked in 
the middle, and but moderately incurved at the sides ; the 


VOL. I. 3 E 


394 CHITONID®. 


last valve is very short and narrow, and the fall from its 
mucro rather abrupt. There are no distinct defined lateral 
and central areas, but the entire exterior of the several 
plates is adorned, except upon the dorsal ridge, which is 
usually marked with coarse wavy longitudinal striae, or 
(often interrupted) raised sulci, with rather large flat- 
topped more or less tear-shaped separate granules, that 
either do not preserve any regular arrangement, or else, 
keeping their pointed ends towards the beaks, seem conse- 
quently to radiate in some little degree from them. The 
margin which is tolerably broad, yet not so dilated as in 
the succeeding species, is somewhat spinosely hairy, and is, 
besides, armed with eighteen tufts or fascicles of crowded 
bristles, that are extremely numerous, of but moderate 
length, and of a pink or yellowish white tint. Four of 
these fascicles precede the first valve, the rest are situated 
at the junction of the several plates of which the Chiton is 
composed. The general colour of the shell is of a greenish 
or olivaceous ash, occasionally mottled with liver-brown, 
sometimes pure white or flesh-colour, sometimes mixed 
white and chocolate brown upon the dorsal ridge; and 
more rarely of a dull crimson, or variegated with crimson 
and white. 

This is a much smaller species than the one next de- 
scribed, and very rarely exceeds three quarters of an inch 
in total length. 

Mr. Clark has communicated a detailed account of the 
animal. ‘ The foot is suboval, very little angular in front, 
and slightly but obtusely tapering behind. The under part 
of the mantle is of a red brown colour. Between the foot 
and the mantle is the branchial cordon, consisting of fifteen 
oblique cord-like, short, close-set, pale brown filaments on 


each side, commencing close to the posterior extremity, 


€ 


CHITON. 395 


leaving only room between the series for the anal aperture. 
This cordon does not quite extend half the length of the 
body on each side; the filaments gradually diminish in 
size from the posterior end, and at the anteal termination 
are not more than half the length of the hinder ones. The 
head is a semicircular puckered frill, within which is the 
circular rugosely-rayed disk of the mouth, with the round 
orifice in the centre. There are certainly no tentacula, and 
no eyes could be detected ; the buccal apparatus consists of 
two elliptical white or pale yellow corneous plates, between 
which is a rather long black strap-shaped tongue armed 
with two lines of tubercles, the inner edges being tricuspid ; 
at the base of the corneous plates is a nervous cordon of 
five minute yellow round ganglia; the tongue is enclosed in 
a muscular esophagus, which enters a very complicated 
stomach and intestine of four or five convolutions, com- 
pacted together by various turns, which, from their com- 
plexity, can scarcely be described, as they lie in a space of 
little more than one-eighth of an inch; at the last turn it 
passes into a rather long rectum, disemboguing in the 
centre of the posterior branchial filaments. The convolu- 
tions can easily be drawn out, and with the esophageal 
canal and rectum form an extent of nearly two inches. 
The folds of the liver and ovarium are immediately under 
the mantle and occupy nearly the whole concave space to 
the head.”"—-We may add that the axile denticle of the 
tongue in this species is oblong quadrate, with an entire 
uncinated apex. The first laterals are very broad and bear 
strongly hooked dark-coloured apices. 

This species is found under stones at low water, and on 
stones and shells to a depth of twenty-five fathoms. It is, 
in the main, an inhabitant of the littoral and laminarian 


zones, and though seldom occurring in abundance, is so 


396 CHITONIDA. 


generally distributed all around our shores, that to enu- 
merate localities would be superfluous. It ranges north- 
wards to the shores of Norway, and southwards to the 
Mediterranean. Some remains of Chitons in the coralline 


crag are doubtfully referred to fuscicularis by Mr. Searles 
Wood. 


C. piscrepans, Brown. 


Valves with numerous fine, irregularly disposed, granules ; 
ligamental border with tufts of bristles. 


Plate LVIII. fig. 4. 


Chiton fascicularis, Woop, General Conch. pl. 2, f. 6 (probably).—PHILIPP1, 
Moll. Sicil. vol. i. p. 108, pl. 7, f. 2 (var. major). — 
REEVE, Conch. Icon. vol. iv. Chiton, pl. 10, f. 53. 
»  erinitus, SOWERBY (not Pennant), Conch. Ill. Chiton, spec. 2, f. 88 to 
91.—Brit. Marine Conch. p. 25]. 
»»  discrepans, Brown, Illust. Conch. G. B. p. 65, pl. 21, f. 20. 


We have preferred the name given to this species by 
Brown, to the generally accepted one of crinitus, an epithet 
revived by Mr. Sowerby in his excellent iconographic 
monograph of the British Chitons. For, independently of 
the disqualifying obscurity of the definition, the northern 
locality, and the small dimensions attributed to his species 
by Pennant—whe naturally would be better acquainted 
with the more abundant fascicularis, with which we regard 
his seven-valved crinitus as identical—forbid our attaching 
the name of that author to the shell we are about to 
describe. 

This Chiton bears so close aresemblance to the preceding 
species as to render its discrimination a little difficult ; the 
smaller size and rather different shape of the granules, the 
elevation and comparative smoothness of the dorsal ridges, 
and the greater proportionate breadth of the margin are the 


CHITON. 397 


more striking features of distinction. It is of a produced 
oblong shape, acutely carinated, moderately beaked and 
not particularly depressed. Its valves are shield-shaped 
and much contracted in front, permitting the margin to 
run up considerably between each valve. The general 
colouring is variable, dirty-flesh colour marbled with 
olivaceous angular lines or markings being the most 
common ; frequently, too, it is pale greenish passing into 
yellowish ash, and the olive-brown markings somewhat 
clouded ; the dorsal ridges, or beak-like series of lanceolate 
cappings, which are distinctly elevated above the granular 
surface, are either smooth or finely striated, and occasionally 
are of a jet black. The hinder, or external edges, are 
but little incurved. The sculpture is precisely that of 
Jascicularis, but the grains are infinitely smaller, closer, and 
more numerous (although the shell itself is much larger), 
and are either subcircular or rounded oval, instead of tear- 
shaped; their arrangement, too, is not precisely identical, 
as for the most part, although not united into chains, they 
run somewhat parallel to the dorsal ridge. The margin is 
very broad, is beset with sea-green somewhat glassy 
hairs, and with eighteen pale tufts of crowded bristles 
similarly disposed as in the last species. 

Specimens from the little islet of Herm, near Guernsey 
(where the shell, which is very abundant in cavities of the 
rocks, at. low water, seems to replace fascicularis, which 
we never met with there), measure an inch and a-half 
in length and three-quarters of an inch in breadth, even 
after the great contraction which they experience in drying. 
(S. H.) Found at Tenby, by Mr. Lyons, according to 
Brown. 

It is truly a southern species, and ranges to the Medi- 


terranean. 


398 CHITONIDA. 


C. Hanteyi, Bean. 


Granules of the central areas moniliformly disposed ; liga- 
mental border aculeated. 


Plate LXII. fig. 2. 


Chiton Hanleyi, BEAN, in Brit. Marine Conch. p. 262, f. 57.—ALpDER, Cat. 
Moll. Northumb. and Durh. p. 73.—THompson, Ann, Nat. 
Hist. new ser. vol. iii, p. 352.—LoviEn, Ind. Moll. Scan- 
dinay. p- 27.—ReEEVE, Conch. Iconica, vol. iv., Chiton, pl. 
28, f. 187, 190. 


This rare and interesting Chiton was first discovered by 
Mr. Bean, of Scarborough, who named it in honour of one 
of the authors of the ‘ British Mollusca.” Although so 
lately detected, it has since then been taken in Finmark 
and other places in the North of Europe. 

It is small, of an oblong, or produced oblong, shape, 
moderately elevated and angular above, and either of an 
uniform whitish or tawny brown tint, but more frequently 
slightly tinged with the latter colour. The valves are not 
polished, and have their hinder edges only slightly retuse ; 
the first is rather large; the breadth at the fifth plate is 
about five and a-half times the length of the exposed portion 
of that valve. The dorsal ridge (the highest part of the 
shelly plates) is neither distinguished by colour nor any other 
particular from the rest of the surface; the mucrones or 
beaks are short but distinct; that of the last valve is a 
little rounded, and as it is not terminal, the posterior slope 
is not abrupt. The sculpture is peculiar, and for the size 
of the shell rather coarse. It consists, upon the central 
areas, of rather distant and not very numerous longitudi- 
nally disposed moniliform rows of granules, that become 
larger as they recede from the middle of the valves; upon 
the anterior plate, and upon the lateral areas, which are 


CHITON. 399 


neither specially indicated by a marginal line nor superior 
elevation, of large papille, which, if exhibiting any ar- 
rangement at all, are set rather concentrically than other- 
wise, and are so much raised as almost to appear peduncu- 
lated. The latter are very deciduous, especially on the 
posterior edge, which, before their obliteration, almost pre- 
sents a dentated appearance. The ligamental border, 
which is not broad, is covered with bristle-like aculeations, 
and, according to Loven, has additional tufts of rather 
longer ones at the posterior corner of the inserted valves. 

Few British examples measure more than a quarter of 
an inch long, and about the seventh of an inch broad ; 
foreign specimens are decidedly larger. 

In England this rare shel] has been taken attached to the 
under sides of rocks at the lowest spring-tides, Scarborough 
(Bean); Cullercoats in twenty fathoms (Alder). In 
Scotland it has been dredged in twenty fathoms east of 
Mull, on a gravelly bottom (M‘Andrew and E. F.); 
in from seventy to eighty fathoms, forty miles from land, 
east of the Noss, Zetland (M‘Andrew); at Oban, Skye, 
Zetland, and upon the West Coast of Ireland (Barlee). 

It is recorded by Lovén among Scandinavian species. 


C. rnuser, Linneus. 


Valves of a shining red, perfectly smooth, or with only strong 
concentric lines upon the lateral areas; border delicately fari- 
naceous, articulately spotted with red and white. 


Plate LIX. fig. 6, and (Animal) Plate AA, fig. 6. 


Chiton ruber, Linn. Syst. Nat. ed. 12, p. 1107.—Lowe, Zool. Journ. vol. ii. p. 
101, pl. 5, f. 2.—FLemine, Brit. Anim. p. 289.—JouHNsTon, 
Berwick Club, vol. ii. p. 38.—Brit. Marine Conch. p. 129.— 
Brown, Ill. Conch. G. B. p. 66, pl. 21, f. 6, 9 —CHemn. Conch. 
Cab. vol. viii. p. 288, pl. 96, f. 813.—Woop, Gen. Conch. p. 14. 
—Dittw. Recent Shells, vol. i. p. 6 (not var.).—SowErRBy, 
Conch. Ill, Chiton, sp. 8, f. 103, 104.—Gouxp, Invert. Massach. 


400 CHITONIDE. 


p. 149, f. 24.—Derxkay, New York Fauna, Moll. p. 165.—Mip- 
DEND. Malac. Rossic. Chit. p. 117.—Rzrvx, Conch. Icon. vol. 
iv. Chiton, pl. 26, f. 175. 

Chiton cinereus, O, Fasr. Fauna Grenl. p. 423 (fide Midd.).— Mar. and 
Rack. Trans. Linn. Soc. vol. viii. pl. 1, f. 3 (probably ; 
not desc.). 

» minimus, SPENGLER, Skriv. Nat. Selks. Kiobenhag. vol. iy. pt. 1, p. 95 
(fide Loyén). 
» levis, LovEn, Index Moll. Scand. p. 28. 


Of the earlier known and imperfectly characterized 
species of Chiton this is the one that, from an examina- 
tion of the Linnean types, we are enabled to identify with 
the greatest certainty. As a British species, however, it 
was not distinctly mdicated, until the publication of Mr. 
Lowe’s admirable paper on this genus, in the Zoological 
Journal for 1825, although apparently designated in 
cabinets by the correct appellation, and delineated in all 
probability in the Linnean Transactions for 1807 as C. 
cinereus. It is of an oval-oblong shape, only moderately 
angulated above, not much elevated, and invariably of a 
dull scarlet, red, or tawny rufous hue, mottled or variegated 
with white markings, which, in the more characteristic 
examples are flexuous, linear, and disposed in obliquely 
longitudinal waves. The posterior edge of the plates is 
decidedly beaked in the middle, but not much incurved 
laterally. The surface of the valves, not of the ligamental 
margin that connects them, is shining, and so smooth as 
not to exhibit any trace of granules under the most powerful 
lens; there are, however faint (and in some examples 
almost obsolete) arched concentric lines of growth, which 
are generally more apparent at the sides than elsewhere. 
The lateral areas are tolerably defined by the comparative 
flattening of their surface, but are not otherwise indicated. 
The mucrones do not differ in substance from the rest of 
the shell. The connecting border is broad, so that the 


CHITON. 401 


proportion of that on each side of the shell is unitedly, at 
the fifth plate, as one to four; it is delicately farinaceous, 
and articulately painted with brick-red and ashy-white, 
so arranged, for the most part, that the latter tint is 
chiefly apparent (and usually in narrow strips) in a line 
with the sutures of the valves. 

Mr. Lowe remarks that the insertional teeth are nine on 
the first valve, ten on the last, and two on the intermediate 
ones. 

The soft parts of the animal are of a flesh-red colour. 
The branchial leaflets on each side extend very nearly to 
half its length, and are about twelve in number. The 
under-margin of the mantle is rather broad in proportion 
to the foot, and the space between the mantle and foot 
very narrow. Hach series of branchial leaflets is also very 
narrow. ‘The hood of the head is narrow and slightly 
extended at the angles. Loven has described and figured 
the lingual teeth. The axile denticle is oblong quadrate, 
the large hooked laterals bear incurved tridentate summits, 
which, however, are not very broad and have nearly equal 
denticulations. 

This species is generally distributed through the British 
seas, but seldom taken in great plenty. It is occasionally 
and not uncommonly found at low water, but its true resi- 
dence is in the laminarian zone, where it is frequent, mostly 
on the under surface of stones, and about the roots of 
Laminaria, in from three to fifteen fathoms water. We 
have observed it in similar localities on both northernmost 
and southernmost coasts. 

It is probably of northern origin, and ranges through 
the seas of Scandinavia, Greenland, and Boreal America, 
extending northwards on the American coast as far as 
the New York province. Middendorff includes it in 

VOL. U. 3 F 


402 CHITONIDA. 


his list of Russian Chitons. Its southern limits are un- 
certain. 


C. cinereus, Linneus. 


Variously coloured, oval, carinated, elevated, irregularly sha- 
greened ; margin very finely granulated. 


Plate LVITI. fig. 1, as C. marginatus (enlarged). 


Chiton cinereus, Linn. Syst. Nat. ed. 12, p. 1107 (from type).—Mar. and Rack. 
Trans. Linn. Soc. vol. viii. p. 22.—Racx. Dorset Cat. pl. 1, 
f. 4?—Lowe, Zoolog. Journ. vol. ii. p. 99.—CHEMN. Conch. 
Cab. vol. viii. p. 219, pl. 96, f- 818 (probably).—SPENGLER, 
Skriy. Nat. Selks. Kiobenhag. vol. iy. pt.1, p. 98 (fide Lovén). 
—Woob, General Conch. p. 21, pl. 3, f. 4 (probably). 

» marginatus, PENN. Brit. Zool. ed. 4, vol. iv. p. 71, pl. 36, f. 22—Monr. 
Test. Brit. p. 1.—Turr. Conch. Diction. p. 33.—FLEM- 
1NG, Brit. Anim. p. 289.—Jounston, Berwick. Club, 
vol. ii. p. 38.—Maceiuiry. Moll. Aberd. p. 184.—Brit. 
Marine Conch. p. 128.—Brown, Illust. Conch. G. B. p. 
66.—Woop, General Conch. p. 21, pl. 3, £ 4 (probably). 
—MaweE, Linn. Conch, pl. 1, f. 2—SoweErey, Conch. Ill. 
Chiton, spec. 3, f. 106 to 111.—Dersu. Lam. Anim. s. 
Vert. vol. vii. p. 505 (in part) ?—Gouxp, Invert. Mas- 
sach. p. 147 (probably; not figure) ; copied by Drxay, 
New York Fauna, Moll. p. 164.— Lovin, Ind. Moll. 
Scand. p. 28.—RExEveE, Conch. Icon. vol. iv. Chiton, pl. 
2/7, f. 182, 183. 

»  fuscatus, Brown, Illust. Conch. G. B. p. 66, pl. 21, f. 17 —Mace11tiyv. 

Moll. Aberd. p. 185. 


The Chitons of the earlier British writers, as well as 
those of the continental conchologists of the last century, 
are almost impossible to be determined with positive cer- 
tainty, since it was not until comparatively of late years, 
that the requisite minute observation was bestowed upon 
the sculpture of their valves. Lowe was the first to 
devote his attention to this point in our indigenous species; 
and Fleming having received from Montagu the types of 
those described in the ‘‘ Testacea Britannica” has enabled 


fr 


CHITON. 403 


us to identify the clearly defined shells of Lowe with the 
previous obscure ones of our native authors. As in the 
present case it is absolutely impossible to say what Pen- 
nant intended by his Chiton marginatus, we have decided 
upon using the prior name of cinereus, although Linneus 
has so inadequately defined his species, that, despite our 
certainty, from actual inspection of his cabinet, we should 
otherwise have avoided using that appellation. Moreover, 
the essential characters were not clearly indicated until its 
publication by Mr. Lowe as C. cinereus. 

This is the commonest of our British Chitons, and by 
far the most variable in diversities of colouring. It is 
of a somewhat produced ovate shape, moderately elevated, 
subcarinated, or rather subangulated above, and with the 
outer edge of each valve mucronated or slightly beaked in 
the middle, and but moderately incurved laterally. Olive 
is, perhaps, the most prevalent tint, but no stress can be 
laid upon colour in this species, since some are orange, 
some nearly white with patches of a chocolate hue, some 
crimson red with white markings, some flesh colour with 
one or two of the valves of a madder-lake, &c.; many of 
the greenish varieties are waved with faint brown lines, or 
speckled with paler dots, and the dorsal ridge is not 
unfrequently pallid, or else painted on either side with a 
paler stripe: the margin is frequently, but not invariably, 
banded or spotted with whitish, opposite the sutures of 
the valves. The lateral areas are only indicated, for 
the most part, by their superior elevation, and are not 
defined by any marginal line or peculiarity of sculpture, 
for the entire exterior is most closely shagreened by small 
(often minute) depressed elongated granules, which do not 
exhibit either a radiating or longitudinal arrangement, but 


are approximately and somewhat concentrically disposed, 


404 CHITONIDA. 


and of nearly equal size throughout. The ligament is rather 
narrow, and arenaceous or minutely farinaceous. 

Mr. Lowe has remarked, that the margin of insertion in 
the separated valves exhibits two nearly equal teeth on 
each side upon the middle plates, twelve upon the last, and 
about ten upon the first. These characters may prove 
useful as subsidiary aids in the identification of the species. 

The red variety, which, as far as our own experience 
goes, is usually the inhabitant of deeper water than the 
greenish or olivaceous type, which latter is very abundant 
under smooth stones, near low-water-mark, upon most 
parts of the English coast, displays a coarser and more 
prominent sculpture upon its valves, and larger granules 
upon its igamental margin. 

The monstrosity C. quinquevalvis (Brown, Ill. Conch. 
G. B. p. 66, pl. 21, f. 22) probably belongs to this species. 

The soft parts of the animal are of a general dusky 
flesh colour, except the centre of the foot, which is deeply 
tinged with livid blue. The under-margins of the mantle 
are of a pale flesh colour. The hood or veil of the head 
is narrow. There are from fifteen to eighteen branchial 
leaflets on each side, all of a dusky flesh colour. Each 
range of branchie extends from behind forwards rather 
more than two-thirds of the length of the body. The 
lingual ribband is slightly shorter than the length of the 
body, but rather wide, and in a middle-sized specimen 
we counted eighty transverse rews of . lingual teeth, which 
for the greater part of its length are tinged with bright 
yellow. The axile denticle is linear, slightly widened 
at its extremity, and colourless, and resembles that de- 
lineated by Lovén in his representation of the teeth of 
asellus. 


This very common species is distributed all round our 


CHITON. 405 


shores wherever there are loose and rather smooth stones 
between tide marks. It is scarcely ever found ranging 
beyond the laminarian zone at farthest. It appears to 
be of northern origin, ranging throughout the Scandi- 
nayian seas: and apparently extending to the coasts of 
Boreal America. Its most southern habitat recorded is 
Vigo Bay in Gallicia, where it has been taken by Mr. 
MacAndrew. It is not included in Middendorff’s list of 
Russian Chitons. 


C. ateus, Linneus ? 


Resembling marginatus, but with the dorsal granules exces- 
sively minute and crowded, and the marginal ones large and 
squamular. 


Plate LXII. fig. 2. 


Chiton albus, Linn. Syst. Nat. ed. 12, p. 1107 (probably)—M aon and Racr, 
Trans. Linn. Soe. vol. viii. p. 22 (from last), pl. 1, f. 4 (uncer- 
tain). — Lown, Zoolog. Journ, yol. iii, p. 80. — FLemine, Brit. 
Animals, p. 290.—Brit. Marine Conch. p. 129.—Brown, Illust. 
Conch. G. B. p. 66, pl. 21, f. 2?—O. Fasric. Fauna Groenland. 
p. 422. — Cuemn. Conch. Cab. vol. vii. p. 290, pl. 96, f. 317 
(badly). — Sowzrpy, Conch. Ill. Chiton, f. 99, 100.— Gouxp, 
Invert. Massach. p. 150, f. 21.—LoviEn, Index Moll. Skandin. 
p- 27.—MippeEnporFF, Malacozool. Rossica, pt. 1, p. 120. 

»,  aselloides, Lowe, Zoolog. Journ. vol. ii. p- 1038, pl. 5, f 5.—Annals Philos. 
1825, p. 387.—Browy, Lllust. Conch. G. B. p. 66. 
»  sagrinatus, CoutHouy, Boston Journ. Nat. Hist. vol. ii. p. 82. 


The characters of this species are by no means striking, 
and the shell, without careful attention, may be confused 
with marginatus, from which the greater coarseness of 
the ligamental scales, in proportion to the granules of the 
testaceous plates, affords the readiest mark of distinction. 
It is small, oval-oblong, rather elevated, more or less 
angulated dorsally, and of an uniform white or yellowish 
white, but often crusted wholly or partially with a black 


406 CHITONIDS. 


coating; whence, probably, the idea of its occasionally 
sombre hue has arisen, since none of the specimens exa- 
mined by ourselves could be termed (as the species has 
been) of a blackish or chocolate colour. The valves are 
rather narrow across, the length of the exposed portion 
being, for the most part, as one to five or six; their 
lateral areas are not well defined, but are distinguishable 
by being rather more swollen, and generally of a more 
opaque yellow than the central ones, The curvature of 
the hinder edge of the plates is not considerable, and the 
beaks are so short, as sometimes to appear obsolete; the 
mucro of the last valve is not at all acute, and the 
posterior descent from it is gentle and arcuated. The 
sculpture is so very minute as not to be distinctly per- 
ceptible except under a powerful glass; to the naked eye, 
indeed, the surface appears glabrous. When very highly 
magnified, however, a remarkably crowded, but depressed, 
shagreening is observable, that, without positively being 
irregular, is neither radiating nor transverse, but from its 
peculiar closeness seems to occupy alike the entire super- 
ficies. Nevertheless there is a kind of diverging arrange- 
ment of meandering fissure-like lines near the beaks, 
where the valves appear rather scratched and punctured, 
than granulated; and the quincuncial system is approached 
upon the lateral areas. The ligamental border is only 
moderately broad, and is adorned with large white vitre- 
ous and almost level scales. 

Mr. Lowe remarks that the terminal valves have eleven 
or twelve adhesional teeth, and the other plates two only 
on each side. 

Few British specimens exceed a quarter of an inch 
in length, and about half that breadth: foreign examples 
are said to attain to twice these dimensions. 


CHITON. 407 


Middendorff describes the branchiz of C. albus as not 
extending beyend the centre of the foot, and as being 
about twenty in number on each side. 

This species has possibly been confounded with its 
near allies on some parts of the coast, so that it is 
difficult to ascertain its true range. Authentic specimens 
are all from the North; among the Hebrides (Lowe, 
Jeffreys, Barlee); in the Orkneys (Thomas); Lerwick and 
Scalloway, Zetland, in ten to twenty fathoms (Jeffreys) ; 
and on the north coast of Ireland (W. Thompson) ; there 
is reason to believe that it is not a common Chiton. It 
appears to be generally distributed through the Boreal and 
Arctic Seas. 


C. asettus, Chemnitz. 


Depressed, rather broad, subcarinated, generally ash-coloured ; 
granulations of the central areas disposed in longitudinal monili- 
form rows. 


Plate LIX. fig. 1, 2, and (Animal) Plate AA, fig. 5. 


Chiton asellus, CHEMN. Conch, Cab. vol. viii. p. 290, pl. 96, f. 816 (fide Loven). 
—Lowe, Zoolog. Journ, vol. ii. p. 101, pl. 5, f. 3, 4—Brown, 
Tllust. Conch. G. B. p. 66, pl. 21, f. 19.—Sprneu. Skriv. Nat. 
Selsk. Kiobenh. vol. iv. pt. 1, p. 99 (fide Lovén),—Desu. Lam. 
Anim. s. Vert. vol. vii. p. 506.— MippEnp. Malac. Rossic. 
Chiton, p. 122. 

» minimus, CHEMN. Conch. Cab. vol. viii. p. 289, pl. 96, f. 814 (fide Lovén), 
from which Woop, Gen. Conch. p. 19, and Dirirw. Recent 

Shells, vol. i. p. 10. 
» cinereus, Mont. Test. Brit. p.3.—Turv. Conch. Diction. p. 34. —FLEMING, 
Brit. Anim. p. 289.—Forses, Malac. Monens. p. 37, animal, 
—Jounston, Berwick. Club, vol. ii. p.88.—Brit. Marine Conch. 
p. 128.—Mace. Moll. Aberd. p. 184.—DiLiw. Recent Shells, 
vol. i. p. 12 (in part)—SoweErpBy, Conch. Ill. Chiton, sp. 4, 
f. 95 to 98.— Gouxp, Invert. Massach. f. 22 ?— ReEEvE, 
Conch. Icon. yol. iy. Chiton, pl. 28, f. 191. — LovEN, Index 

Moll. Scand. p. 27. 
», albus, Matron and Rack. Trans. Linn. Soc. vol. viii. pl. 1, f. 4 (probably). 


Owing to the great confusion which has taken place 


408 CHITONIDA. 


between this species and the traditional marginatus, as well 
as the circumstance (proved by the Linnean cabinet) that 
this was not the shell originally described as C. cinereus, we 
have retained the name attributed to the species by Mr. 
Lowe, who first clearly defined it, although the asellus of 
Chemnitz is nearly as obscurely indicated as the cinereus 
of Linneeus. 

The shape of this Chiton ranges from oval to ovate 
elliptic, and the height from rather depressed to decidedly 
elevated: in the latter case the dorsal ridge, which typically 
is very obtusely subangular, is much more sharply angu- 
lated. The plates, which are short in proportion to their 
width, have their posterior curvature almost uninterrupted 
by any central rostration, the summit of the valves not dif- 
fering from the general surface in either colour, sculpture, 
or elevation of area. The valves, towards their bases, are 
concentrically grooved with rather profound sulci of in- 
crease, and are divided into lateral and central triangles 
rather by the style and disposition of the shagreening than 
by any superior tumidity or line of demarcation on either. 
The raised granules upon the central areas are arranged in 
very numerous longitudinal moniliform or beaded series, 
which are for the most part nearer to each other on the 
more elevated portion of the valves than at the sides; the 
granules upon the lateral triangles, as well as those of the 
anterior plate, have a somewhat radiating disposition, 
are very close-set, and become coarser and less regular 
towards the ligament. This last is roughly arenaceous 
and narrow, the margin on each side taken together rarely 
exceeding, even if it equal, one quarter the breadth of 
the plates. 

The general colouring is sallow, fulvous, or cinereous, 


often mottled or irregularly speckled upon the ligament 


CHITON. 409 


with smoke-black, and not unfrequently painted with lon- 
gitudinal linear markings of the same hue upon the central 
areas. In certain examples, and especially in those from 
Scotland, the surface is wholly or partially concealed by a 
black incrustation ; frequently, too, a slight coating of this 
substance imparts a band-like effect to the posterior half of 
each plate ; and sometimes probably this tint may be 
regarded as the permanent colour of the shell, although in 
the majority of specimens it is plainly superficial. In the 
more elevated variety, the lateral triangles are more raised, 
and the mucro of the hinder valve is more sharply pro- 
minent. 

Mr. Lowe remarks that the plates are destitute of mar- 
ginal teeth, but have their imner edges crenulated or 
granular. Although several of our specimens exceed half 
an inch in length and one third of an inch in breadth, we 
regard these dimensions as the full average. 

The soft parts of the animal are of a somewhat tawny 
flesh-colour. The hood of the head is rather thick mar- 
gined. The branchial cordons are rather broad, and do 
not extend on each side to half the length of the body. 
There are about ten branchial leaflets on each side. The 
space between the foot and the corner edges of the mantle 
on each side is rather broad. The lingual dentition has 
been described and figured by Lovén; the axile denticle 
is widened out at the base, and remarkably contracted and 
narrow in the centre; the large uncinated black tipped 
lateral teeth are very unequally denticulated at their in- 
ward extremities. 

This species is as common and abundant below the 
laminarian zone as cinereus is above; perhaps even more 
so, for we can scarcely dredge anywhere on our coasts 
without taking it adhering usually to dead or living shells. 


VOliee Kil 3) @ 


410 CHITONIDA. 


It is found ranging to far distances from land, and to 
greater depths than any other of our Chitons, having been 
taken in forty, fifty, eighty, and even one hundred fathoms 
around the Zetlands. It is occasionally met with at very 
low water, and is abundant in from four to thirty fathoms. 
It ranges from the Scandinavian seas to the northern shores 
of Spain. 


C. cancettatus, Sowerby. 


Resembling ased/us, but much narrower; the back more ele- 
vated, quite rounded, not at all beaked. 


Plate LIX. fig. 3. 


2 Chiton albus, PuLTENEY, Hutchins, Hist. Dorset, p. 25. — RackeTr, Dorset 
Catalog. p. 25, pl. 1, f. 3. 
»  cancellatus, LHAcH ? SowERBy, Conch. Illust. Chiton, spec. 5, f. 
—REEvE, Conch. Icon. vol. iy. Chiton, pl. 23, f. 152. 


The supposed Ohiton cancellatus of Leach,—for the species 
was never characterised by that naturalist, and Mr. Sowerby 
doubtingly gives him the reputation of founding it, solely 
from the traditionary authority of collectors,—approaches 
so closely to C. asellus, that Middendorff, whose elaborate 
work on the Russian Chitons exhibits remarkable powers 
of observation, has held it to be a mere variety. Since, 
however, it differs in very many points, we have held it 
advisable to retain it for the present, but propose merely 
to enumerate those characters which seem more strikingly 
to separate it from the shell we have compared it to. All 
the specimens we have seen are of a squalid, but uniform, 
whitish tint throughout, and are far smaller, much nar- 
rower (the length being twice the breadth), and propor- 
tionately more elevated than those of asellus. The back is 


peculiarly rounded, and the valves are not at all beaked. 


CHITON. 41] 


The granules of the lateral triangles, whose shagreening is 
occasionally almost obsolete, scarcely display any radiating 
arrangement; the longitudinal ones of the central areas 
are rather oblique, and somewhat rhomboidal in shape ; 
the series are so closely disposed that the punctured 
interstices are more conspicuous than the raised sculp- 
ture, from the grains being comparatively large, flat, and 
touching, so as almost to present a level surface. When 
highly magnified, the somewhat oblique longitudinal inter- 
stices appear to be decussated, lattice or diamond fashion, 
by still finer striulee, whence probably the name cancellatus 
has been derived. 

Our largest examples are not a quarter of an inch in 
length, and hardly exceed an eighth of an inch in breadth. 

The C. alveolus of Sars, judging from Loyen’s deserip- 
tion (Ind. Moll. Scand. p. 27), must bear some resemblance 
to this species, and Payraudeau’s figure of his C. Rissot 
(Moll. Corse, p. 87, pl. 3, f. 4, 5) reminds one not a little 
of its form and sculpture. 

In about eight to ten fathoms, St. Peter’s Port, Guern- 
sey; Weymouth and South Devon (8. H.) In fifteen 
fathoms off Douglas Bay, Isle of Man (E. F.); Oban, 
fifteen fathoms; in fifteen to twenty fathoms near land, 
Zetland; and in forty fathoms in a tideway off Fitful 
Head (M‘Andrew and E. F.) ; Loch Carron and adjacent 
lochs, m ten to twenty fathoms (Jeffreys). 


C. avis, Pennant (2). 


Much elevated, narrow, red ; ligament reticulated. 


Plate LVIII. fig. 3. 


Chiton levis, PENNANT, Brit. Zool. ed. 4, vol. iv. p. 72, pl. 36, f. 3 (probably ).— 
Mont. Test. Brit. p. 2,— Maron and Rack, Trans. Linn. Soc. 


412 CHITONID&. 


vol. vill. p. 21.—Turr. Conch. Diction. p. 33.—Lowe, Zoolog. 
Journ. vol. ii. p. 97, pl. 5, f. 1.— FrLemine, Brit. Animals, p. 
290.—Brit. Marine Conch. p. 129.—Woop, General Conch. p. 
22. — SowErBy, Conch. Illust. Chiton, species 7, f. 101, 102.— 
Purwiert, Moll. Sicil. vol. i. p. 107, pl. 7, f. 4; vol. ii. p. 83.— 
ReeEvE, Conch. Icon. vol. iv. Chiton, pl. 26, f. 125. 
Chiton marginatus, PuLTENEY, Hutchins, Hist. Dorset, p. 25 (probably).— 
Maron and Rack. Trans. Linn. Soe. vol. viii. pl. 1, f. 2. 
—Rackert, Dorset Catalog. p. 25, pl. 1, f. 2 (probably). 
—Lam. Anim. s. Vert. (ed. Desh.) vol. vi. p. 492 (in part 


only). 
»  achatinus, Brown, Illust. Conch. G. B. p. 65, pl. 21, f. 4, 12, 13, 15. 


»  corallinus, Risso! H. N. Europe Mer. vol. iv. p. 268 (fide Philipp1).— 
Loven, Index Moll. Scandinay. p. 28. 


Considerable doubt exists as to this being the species 
actually intended by Pennant under the epithet Jevis, 
but as an unbroken chain of traditional authority has 
sanctioned the identification, and his brief diagnosis and 
wretched figure will not agree better with any other 
British Chiton, we have, although with some hesitation, 
attributed to that author the merit of having founded 
the species. Its peculiar margin enables even the most 
casual observer to distinguish it at a glance from its native 
congeners. 

The shape ranges from oval to produced elliptical, 
and the shell is much, and rather suddenly, elevated 
dorsally, assuming in the more typical and laterally com- 
pressed examples a more angular appearance, from the 
plates being more or less flattened (instead of convex) 
at the sides. The middle portion of the posterior or 
externally visible edge of the valves is, in the young, 
decidedly beaked, in the middle-aged specimens but slightly 
so, whilst, in aged individuals, owing to the frequent dorsal 
erosion at that stage of growth, this mucronation becomes 
obscure or obsolete; the iateral portions have a tendency 


to slope backwards. The general colouring is red or 


CHITON. 413 


rufous brown (the smaller the specimen the more vivid, 
for the most part, is the tint), either uniform, or va- 
riegated with a marbling of white or green on a ground 
which is more dusky in the large northern examples, 
than in the smaller but more elegant southern ones. The 
surface of the plates, which are comparatively long con- 
sidering their narrowness, is a little shining, and to the 
eye apparently smooth; a powerful lens reveals an ex- 
tremely minute depressed kind of obscure and irregular 
shagreening. The division of areas is only, if at all, 
indicated by the sudden elevation of surface at the com- 
mencement of the lateral triangles; the concentric lines 
of growth are not unfrequently a little prominent. The 
declivity at the termination of the posterior mucro is 
not abrupt. The connecting or ligamental border is re- 
markably broad, that on each side of the fifth plate oc- 
cupying together from two-sevenths to (in the young chiefly) 
even two-fifths of the entire width. It is a little glossy, 
very closely reticulated in diamonds, and if not display- 
ing the mottled painting of the testaceous plates, is often 
curiously marked on its red ground with two pair of 
conspicuous white spots, situated in a line with the sutures 
of the terminal plates at either extremity. 

Mr. Lowe observes that there are twenty small inser- 
tional teeth on the first plate, and four, of which the 
first is larger than the rest, upon each side of the middle 
valves. He remarks, likewise, that the C. septemvalvis of 
Montagu (Test. Brit. p. 3.—C. discors, Maton and Rack. 
Trans. Linn. Soe. vol. vii. p. 20.—Brown, Ill. Conch. G. 
B. p. 67) belongs to the present species rather than to the 
marginatus of authors, its margin being described as 
reticulated, One of our larger examples measures half 
an inch in breadth, and fully eleven lines in length. 


414 CHITONIDA. 


We have, unfortunately, no note of the soft parts of 
the animal, ; 

This is a scarce species, never occurring gregariously. 
It ranges in from low-water-mark to forty fathoms water, 
but is chiefly an inhabitant of the coralline zone. It 
appears to be present in all our marine provinces. Among 
localities, may be cited Torquay and Weymouth (S. H.); 
Exmouth and bays near Swansea (Jeffreys); fifteen to 
eighteen fathoms off Douglas Head, and elsewhere on 
the coast, off the Isle of Man (EK. F.); in seven to twenty- 
seven fathoms off Lundy Island (M‘Andrew); twelve 
fathoms Orkney, and fifteen to twenty fathoms Zetland 
(M‘Andrew); in forty fathoms off the Mull of Cantire 
(Hyndman); Oban and Loch Long (Barlee) ; “on both 


99 


sides of Ireland, but very rare” (Thompson). 


It ranges from Norway to the Mediterranean. 


C. marmoreus, O. Fabricius. 


Valves broad, most minutely shagreened; ligamental margin 
coriaceous. 


Plate LVIII. fig. 2, and Plate LIX. fig. 4. 


Chiton marmoreus, O. Fasric. Fauna Groenlandica, p. 420.— MippEenporrr, 
Beit. Malacozoo]. Rossic. (Mem. Sc. Nat. Petersburg, vol. 
vi.) p. 103. 
ew rubro et albo marmoratus, CHEMNITZ, Conch. Cab. vol. viii. p. 287, pl. 
96, f. 812 (badly). 
ruber, SPENGLER (not Linn.), Skriv. Nat. Selks. Kiobenhag. vol. iv. pt. 1, 
p. 92 (fide Lovén).—Lovin, Index Moll. Scand. p. 28. 
levigatus, FLEMING (not Sowerby), Edinb. Encyclop. p. 113; Brit. 
Animals, p. 290.—Brit. Mar. Conch. p. 129.—Browy, III. 
Conch. G. B. p. 67, pl. 21, f. 1, 16. — Rerve, Conch. Icon. 
vol, iv. pl. 27, f. 179. 
latus, Lows, Zoolog. Journ. vol. i. p. 103, pl. 5, f. 6, 7. — SowERBy, 
Conch. Ill. Chiton, spec. 9, f. 113. 
fulminatus, CouTHOUY, Boston Jl. of Nat. Hist. yol. i. p. 80, pl. 3, f. 19. 


°° 


CHITON. 415 


—Gou.p, Invert. Massachus. p. 148, f. 23. (probably).— 
Dexay, New York Fauna, Moll. p. 165, pl. 10, f. 99 (pro- 
bably). 

Chiton pictus, BEAN, Brit. Marine Conch. p. 264, f. 56. 


Otho Fabricius, who appears to have been the first who 
directed his attention to the insertional teeth in the valves 
of: Chiton, has described this Chiton in his Fauna of 
Greenland, a work which, considering the carefulness and 
sufficiency of his descriptions, contrasting strongly with 
the loose, curt, and indefinite language of most of the 
subsequent writers upon Conchology, has been singularly 
neglected by our writers upon shells. 

The shape of this Chiton, our largest British species, is 
ovato-elliptic, the form being rather broader in front than 
behind, where also the shell, which is moderately elevated, 
becomes rather more depressed, and the dorsal angulation, 
which even anteriorly is more or less obtuse, becomes 
almost or wholly obsolete in the larger examples. The 
plates or valves are rather glossy, and apparently smooth, 
but when magnified exhibit an extremely minute shagreen- 
ing, wherein the granules, which, although remarkably 
numerous, cannot be termed crowded considering their 
size, seem all of the same dimensions, and are not disposed 
in any peculiar arrangement upon the several areas; the 
lines of increase are tolerably distinct. The lateral tri- 
angles are indicated by their slight superior elevation 
either wholly or anteriorly; in the latter case there is 
occasionally an indistinct radiating approximate sulcus, or 
the central portion is hollowed out, so that the hinder edge 
seems slightly raised likewise. The posterior dorsal edge 
is a little incurved laterally, and rather abruptly beaked in 
the centre; the mucro is short, and not distinguished from 
the rest of the surface by either colour, substance, sculp- 


416 CHITONID&. 


ture, or elevation. The hinder valve is both short and 
narrow ; it is slightly and indistinctly submarginated at its 
extremity. The connecting ligamental margin is cori- 
aceous, very narrow in the young (where the thin edge 
contracts extremely in drying), and but moderately broad, 
in proportion to the wideness of the plates, in the adult, 
the two edges together averaging, at the fifth valve, even 
in the large Scotch examples, only about two-sevenths of 
the breadth of that plate. ‘The colouring consists of linear 
zigzag markings, flammules, or angular spots of white, 
greenish, or flesh-colour, upon a ground of rufous or 
Turkey red, with the posterior edge often prettily articu- 
lated with darker tinted and white spots, or vice versd, 
the pale colours preponderating; the leathery margin is 
either of an uniform fulvous brown, or barred with dusky 
olive upon a tawny ground. Mr. Lowe states that the 
first plate is furnished with nine broad teeth, the last with 
eight broad ones; the intermediate valves with two on each 
side. The levigatus of Macgillivray (Moll. Aberd. p. 185), 
with a granulated border, is evidently not the species so 
named, but possibly a young asel/us. Scotch specimens are 
occasionally found seventeen lines broad and eleven long, 
and sometimes even of still larger dimensions; English 
individuals are much smaller. 

The animal, according to Middendorff, has its range of 
branchial leaflets extended to half the entire length. There 
are about twenty-four on each side, placed rather distant 
from each other. 

This is one of our rarer and more local Chitons as well 
as the finest species we possess of the genus. It is essen- 
tially a northern form. In the north-east of England it 
has been taken at Scarborough (Bean); among rocks below 
Dunstanborough Castle, very rare (Embleton); a single 


pape > 


CHITON. 417 


living example at Cullercoats (A. Hancock); disunited 
valves on Whitley Sands (fryer); rare on the Black 
Rocks, Leith, Frith of Forth (Knapp); Gair Loch and 
Firth of Clyde (Smith); Skye at low-water, and else- 
where in the Hebrides (E. F.) ; plentiful in seven fathoms 
at Lerwick, Zetland (KH. F.); “rare, but found on the 
north, east, and west coasts of Ireland;” in fourteen 
fathoms Strangford Loch (W. Thompson). 

It ranges throughout the Scandinavian and Arctic Seas, 


and along the coasts of Boreal America.* 


* In Turton’s “ Conchological Dictionary of the British Islands,” (p. 34,) a 
Chiton punctatus is thus described: “ Shell with eight valves, raised, beaked, and 
margined, very conyex, deep red, finely and distinctly punctured all oyer.” To 
this brief and most imperfect diagnosis is added the remark, that these punctures 
seem the sole distinguishing feature between it and /evis, and that it is a quarter 
of an inch long. The very rude delineation (fig. 10) which accompanies the 
text, bears some slight resemblance to marmoreus; the language is more applicable 
to an eroded /evis. The specimen itself, found by Mr. O. Kelly at Portmarnock, 
in Ireland, will probably be transmitted to us before the conclusion of the 
* British Mollusca.” 


VOL, Il. 3H 


418 


PATELLID. 


Ir would seem to be a law in both animal and vegetable 
kingdoms that no character, whether of structure or form, 
preserves an equal value in every tribe, but varies in its 
importance ; in one group characterising a class, in another 
scarcely determining a species. Important as the ar- 
rangements of the respiratory system are among the 
Mollusca, we have an example in the family before us 
of their degradation to a mere generic value. Cuvier as- 
sociated the Chitons and Limpets in one order distinguished 
from all other sections of the Gasteropods by the dispo- 
sition of the branchial leaflets, yet no malacologist who 
attends closely to the conformation of the soft parts 
in Chiton and Patella, would hesitate, in the present 
state of our knowledge, to maintain that the latter genus 
had more affinity with Acmea and its allies, than 
with the former, however different the branchial arrange- 
ments appear. The difference is more in appearance than 
in reality; and the resemblance between the branchial 
arrangement of Chiton and Patella, in like manner, is more 
apparent than real, although Cuvier mistook it for an 
indication of affinity. The cyclobranchiate gill of Patella 
seems to us a single long branchial plume, exserted from 
the cervical cavity, and coiled round between mantle 
and foot. Without going so far as Professor Loven, who 
has united the entire shelled patelliform Mollusks in one 


genus, we feel bound on anatomical and _ physiological 


Ee 


a 


Se 


‘ 


PATELLIDA. 419 


grounds, to associate them in one family, and in doing 
so feel at the same time, that, without making any 
scientific sacrifice, we are relieving the conchologist of what 
seemed to him one of the most anomalous and unnatural 
disunions of similar shells, which the naturalist, through 
overvaluing the characters presented by the respiratory 
organs in the Limpet tribe, had proposed. Between the 
genera themselves, however, it is very difficult to dis- 
tinguish by shell alone. 

The animals of the Patella tribe have distinct heads 
furnished with two distinct tentacles, which are in some 
genera provided with eyes towards their external bases, 
in others are eyeless. They have a very large and power- 
ful creeping disk, between the sides of which and the 
mantle are seen, in some genera, the branchiz forming a 
cordon of fine lamelle ; in others these organs are grouped 
into a distinct plume, and lodged in a cervical cavity. 
The sides of the foot are never ornamented with cirrhi, 
but the margin of the mantle is sometimes cirrhated, 
sometimes entire. The mouth is armed with a pair of 
corneous jaws, between which we find the extremity of 
a very long ribband-like tongue, bearing a powerful ar- 
mature of denticles. The arrangement of the denticles 
is constant in each genus. The shell is conical and 
cup-shaped: it is entire, and its apex is usually turned 
towards the head of the animal, in one genus from it. 
On the inner surface of the shell are seen the muscular 
impressions from which the position of the head of the 
animal may be known when the soft parts are removed. 


420 PATELLIDA. 


PATELLA, Linnzus. 


Shell ovate, or nearly round, conical, with a subcentral 
anteal apex, surface smooth, or with radiating striz or 
ribs ; interior with a crescentic muscular impression, inter- 
rupted in the region of the animal’s head. 

Animal with two subulate tentacles, bearing eyes on 
the outer sides of their swollen bases; mantle-margin 
fringed ; branchial plume forming a fixed cordon of minute 
close-set plates, placed between the mantle and base of 
foot, and ranging nearly round the body; foot a large, 
ovate, or round disk, with plain sides. Buccal mass with 
cartilaginous jaws ; lingual ribband very long, armed with 
transverse ranges of teeth, of which six in each series 
belong to the rachis, flanked on each side by three ac- 
cessorials. 

The Limpets, properly so called, few as the species are 
upon our shores, though none of our Gasteropods are so 
prolific individually, may be grouped under two sections, 
to which the names Paretia and Partna were respectively 
applied by Dr. Leach, who appears to have regarded 
them as distinct genera, probably more from love of 
excessive analysis of species than from knowledge of their 
true differences, since, so far as we are aware, the dis- 
tinguishing characters have not been noted. In the rock 
Limpets (Pateria, as P. vulgata, and P. athletica), the 
branchial cordon extends very nearly round the body, 
being unsymmetrically interrupted on one side near the 
neck, and the mouth is emarginated below; in the 
seaweed Limpets (Partna, as pellucida), on the other 
hand, the branchial cordon is interrupted for a consider- 


PATELLA. 421 


able space in front of the head, and terminates nearly 
symmetrically on each side of the neck; the mouth, too, 
is entire below. Before recognising these distinctions as 
of generic value, it is desirable to ascertain whether they 
be constant in exotic forms of the two groups, both of 
which have representatives in almost all the seas of the 
globe. 


P. vuteata, Linneus. 


Substance greyish, olivaceous or yellowish, never white; ribs 
not armed with a regular series of tooth-like scales: spatula 
opaque white. 


Plate LXI. fig. 5. 6. 


Lisrrr, An. Angl. pl. 5, f. 40.—KNorr, Délices des Yeux, pt. 
6, pl. 27, f. 8. 
Patella vulgata, LinNaus, Syst. Nat. ed. 12, p. 1258.—Pxnwn. Brit. Zool. ed. 4, 
vol. iy. p. 142, pl. 89, f. 145. — Putrrenry, Hutchins, Hist. 
Dorset, p. 51. — Donoy. Brit. Shells, vol. i. pl. 14.— Monr. 
Test. Brit. vol. ii. p. 475, conical var.— Maron and Rack. 
Trans, Lin. Soc. vol. viii. p. 229, part.—Rack. Dorset Catal. 
p- 58, in part, pl. 23, f. 1, 2, 8.—Turvr. Conch. Diction. p. 135, 
in part. — Fiemine, Brit. Anim. p. 286.— Forszs, Malac. 
Monens. p. 36, var. a.—Jounston, Berwick. Club, vol. ii. p. 35, 
in part.—Mace. Moll. Aberd. p. 180.—Brit. Marine Conch. 
p- 130, chiefly—Brown, Ill. Conch. G. B. p. 63 (all but var. 
3), pl. 20, f. 5, 15, 17. — Bosc, H. N. des Coquilles, vol. iti. 
pl. 25, f. 5, 6. — Dituw. Recent Shells, vol. i. p. 1032 (not 
var.).—— Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 535. — 
Woop, Index Testac. pl. 37, f. 38.—Buarnv. Man. Malacol. 
pl. 48. f. 1. 
»  depressa, PENN. (not Helbling), Brit. Zool. ed. 4, vol. iy. p. 142, pl. 89, 
f. 146. 
Common limpet, Humpureys and Da Cos. Nat. Hist. Shells, pl. 2, f. 1. — Ann. 
N. H. vol. i. p. 482. 
Patella vulgaris, Da Costa, Elem. Conch. pl. 1, f. 1, 2, 8; Brit. Conch. p. 3, 
chiefly, pl. 1, f. 1, 2. 
2 Die graue scharfegeribte Patelle, KAMMERER, Cab. Conch. Rudolst. (1786), p. 
15, pl. 3, f. 6. 


The Limpets are a peculiarly difficult tribe to divide 
into species, since they not only present but few tangible 


422 PATELLIDZ. 


features for description, but those few are likewise sus- 
ceptible of great modifications. The P. vulgata is not the 
least variable of its genus, and exhibits considerable varia- 
tion in shape and colouring ; which seems partly to depend 
upon growth, partly to result from local circumstances. 
Middle-aged specimens—generally the most characteristic 
stage in Patella,—of nearly an inch and a half long, 
are of a subovate figure, subconical, strong, and for the 
most part of a rather pale olive or dirty and somewhat 
olivaceous yellow cast; in the former case, obscurely 
marked with rather narrow rays of dark grey; in the 
latter, with the rays generally much interrupted, chiefly 
conspicuous in the more depressed portion of the surface, 
and often of a rich chocolate brown. In one of our 
varieties the darker rays are very obscure, and the small 
ribs are somewhat radiatingly speckled with white; in 
another the entire exterior, as well as the inner edge, is 
of a dark brown, and the interior, the spatula excepted, 
is of avery pale olive hue. The inside partakes of the 
external painting (the substance of the shell, and not 
merely the superficies, being coloured) but is somewhat 
paler, and is always slightly iridescent; the spatula- 
shaped central portion is of an uniform opaque and rather 
bluish white, and not edged with orange. The margin is 
less ragged than in the succeeding species, but is angularly 
undulated in the more strongly ribbed forms, almost plain 
(but never quite so, unless abraded) in the simply striated 
ones. These are the two principal varieties as to sculp- 
ture : in the more characteristic individuals of the former, 
and such are generally conical, there are about twenty- 
five strong and bluntly angulated unarmed ribs, each with 
about three or four interstitial strie ; im the latter the ribs 
are almost obsolete, or actually divided into irregular 


PATELLA. 493 


slightly raised simple strize, with which the entire surface 
is densely covered. 

Aged shells have usually a more rounded contour, and 
greater elevation; their obtuse vertices are rather more 
central than in the young. These last display a richer 
style of colouring than the more mature individuals, being 
not unfrequently of an orange red, with the inside beauti- 
fully iridescent and adorned with rays of a bright: red ; 
the spatula at that stage of growth is not yet developed. 
In some the ribs are roughened by nodulous projections, 
but these nodules are irregular, generally few in number, 
and not fang-shaped. Sometimes they are large and 
blunt (in which case the ribs are broad and strong) ; some- 
times, too, there are crowded vaulted scales upon the cos- 
tella, owing to the more than ordinary projection of the 
closely set concentric wrinkles, which, although delicate, 
are always more or less apparent upon the surface. These 
examples form the nearest approach to athletica, especially 
when the ribs are nearly white; and were it not for the 
different colour of the substance of the shell, might, at a 
stage when the whole of the distinctive features are not 
developed, be readily mistaken for that species. 

Our larger examples measure twenty-eight lines in 
length, and twenty-three in breadth. 

The animal is of a general bluish or dusky hue; its 
head is dusky with long, strong, conical tentacula, which 
are tinged towards their extremity with a bluish or dusky 
tint, and bear a small black eye on the outside of each 
of their swollen bases: when the creature is at rest it 
bears its tentacles contracted and appressed with their 
tips curled towards each other. The lips of the mouth 
are puckered, thickened above, and at the sides narrow, 
and as if emarginate below. The jaws are tinged with 


424 PATELLIDA. 


dusky. The very long tongue is armed with numerous 
transverse series of denticles; of these, four nearly similar 
narrow ones, with brown hooked even extremities, form 
the centre of the rachis, and two brown hooked lower- 
placed broader ones flank them, bounded by three colour- 
less accessorials on each side. ‘The length of the tongue 
exceeds that of the shell; in a limpet two inches and a 
half long it exceeded those dimensions by three-twelfths. 
On this tongue we counted one hundred and sixty trans- 
verse bands of teeth: as each band is composed of twelve 
denticles, there were no fewer than one thousand nine 
hundred and twenty teeth in all: twenty-two of the trans- 
verse bands belonged to the winged part of the tongue. 
The foot is either entirely of a smoky hue, or tinged with 
dusky yellow on the disk, and bluish on the base. The 
branchiz form a nearly complete cordon of closely packed 
drab or yellowish plates, rounded at their margins; the 
series commences as if protruded from the cervical cavity 
on the left side of the head, and coiled backwards round 
the body to terminate, after gradually becoming smaller and 
smaller to its origin. The mantle is yellowish white, often 
tinged with dusky, and is fringed with fine filiform cirrhi, 
which, as Mr. Clark was first to observe, differ in their 
arrangement from those of the next species insomuch as 
they are arranged in three alternations of different lengths. 

The common Limpet is universally distributed around 
our coasts, living on the surface of rocks and stones 
between tide-marks. Although capable of moving about 
with facility, when well-grown it appears to become lazy 
and sedentary, often living in crevices, where having once 
lodged it remains till it grows too large to come out. In 
such cases it certainly cannot subsist on fuci, as generally 
supposed, but must depend upon the waves for a supply of 


PATELLA. 425 


some other kind of food, possibly infusorial. When it 
moves about, it makes upon the rock a curious fucoid-like 
track of some breadth, probably caused by the edges of 
the shell. On calcareous rocks, and especially on chalk, it 
frequently, as it were, excavates a cavity for itself, appa- 
rently by the action of the carbonic acid set free during 
respiration, since the marks of the action of the ciliary 
currents from the gills are distinctly visible. This animal is 
sometimes used for food, though much too leathery to be- 
come a delicacy. As bait it is very valuable to fishermen. 
Dr. Johnston, in some very interesting notes on the Lim- 
pets of the Berwickshire coast,* calculates that in Berwick 
alone there is an annual consumption of no fewer than 
11,880,000 Limpets for this purpose. ‘‘ From constant war- 
fare,” he says, ‘the numbers have now greatly decreased ; 
there is not now one out of ten that there were twenty 
years ago, and the collecting of them has become tedious 
enough.” In the ‘“ Annals of Natural History” for June 
1839, there is a very interesting paper by Mr. Patterson 
on the use of the Limpet as food in the north of Ireland. 
It is therein stated that the Limpet gatherers, thirty in 
number, at Larne in Antrim, earned in one season of four 
months, no less than one hundred pounds sterling. 

The Patella vulgata ranges along the Atlantic shores of 


Europe. 
P. aratetica, Bean. 


Substance of the shell white ; ribs very numerous, narrow, 
much elevated, armed with toothlike scales in a regular series, 
interstices wholly or partially stained with rich brown ; inside 
more or less of a whitish cast, spatula tinged with orange- 
yellow. 


* Berwickshire Nat. Club Report for 1842. 


VOL. If. ol 


426 PATELLIDA. 


Plate LXI. figs. 7, 8. 


? Patella vulgata, Linn. Fauna Suecica, ed. 2, p. 534. 


a 5 depressed var. Mont. Test. Brit. vol. ii. p. 476. 

»> aspera? Puitipri, Moll. Sicil. vol. i. p. 111; vol. ii. p. 84 (from 
specimens). 

»  vulgata, var. B., FoRBES, Malac. Mon. p. 36. 

= » var. 1, JOHNSTON, Berwickshire Club, vol. ii. p. 36. 


»  athletica, BEAN, Brit. Marine Conch. p. 264, f. 108.—ALpER, Cat. 
Moll. Northumb. and Durh. p. 71. 
»  vulgata, var. albumena, Brown, Ill. Conch. G. B., p. 63, pl. 20, f. 12, 
14, 


In assenting to the separation of this shell from the 
preceding, we shall probably incur some animadversions. 
A long and peculiar study of the Limpets has, however, 
induced us to believe that the characters briefly enume- 
rated in our diagnosis are of at least equal value to those 
by which caerulea, Candei, &c., are distinguished from 
oulgata. 

Ordinarily this shell is rather depressed, yet it is not 
unfrequently subconical, although it never, we believe, 
attains to that elevation so customary in aged examples of 
the preceding species. In form, it ranges from rounded 
oval, passing through simply ovate, to elliptic, a shape 
which is far more habitual to it than to vulgata. The 
substance of the shell is thick, nearly opaque, and squalid 
white; externally the surface is more or less adorned with 
chestnut, reddish brown, or chocolate colour in the inter- 
stices of the costelle, which latter are always white, 
though at times sparingly painted with brown likewise. 
In the more characteristic examples, the darker tint of the 
narrow interstitial spaces alternating with the pure white 
of the raised portion of the sculpture, presents a very 
beautiful and frequent radiation; very often, also, the 
colouring is disposed in interrupted concentric zones; 
sometimes, even, it is almost entirely absent. The in- 


Tuya i ahs 


PATELLA. 427 


terior, which is rarely at all nacreous, is either whitish, or 
of a pure orange-yellow, with which hue the spatula, in 
the more typical specimens, is more or less stained or 
bordered: the margin of the shell is often articulated with 
brown and white, and is greatly jagged or dentated, owing 
to the projection of the external costelle. These last 
are extremely numerous, more or less sharply angulated, 
prominent considering their narrowness, and regularly, 
crowdedly, and finely muricated; they are sometimes 
simple, and of equal width to each other (in some indi- 
viduals, chiefly foreign, there are as many as from 100 
to 150, and all so closely set that the interstitial spaces 
are no broader than themselves); sometimes arranged in 
triplets, of which the central riblet is rather the largest. 
The vertex, as in vulgata, is rather blunt, and is less 
subcentral in the more elongated than in the broader 
examples. 

None of our known British specimens are quite so large 
as certain of the preceding species, but we possess some 
(possibly exotic ones) that measure nearly two inches in 
length and about an inch and a half in width, which is 
twice the general size of those taken upon our coast. 

Our belief in the propriety of keeping this Limpet dis- 
tinct from vulgata is importantly supported by observations 
communicated to us by Mr. Clark, who, when not aware 
that the form had been regarded and named as a separate 
species, decided for himself that it was such, after an 
examination of the shells of several hundreds of both and 
a careful comparison of their animals. We have recently, 
with his notes in hand, carefully compared the soft parts of 
each species alive, and can fully verify the following ac- 
count. Of athletica he remarks, that ‘‘the animal differs 


specifically from vulgata; its colour is invariably much 


428 PATELLIDA. 


lighter, and has the general substitution of the various 
shades of orange-yellow for the lead or pale smoke-brown 
of its congener. The mantle is edged with flaky-white 
jointed filaments of only two lengths, twice as short and 
twice as thick as those of vulgata. The branchial plates 
are in proportion longer, thinner, paler, and more round at 
the points. The foot is of various hues of orange-yellow, 
with scarcely any anastomosing lines,* and its margin is 
more fleshy. The head is of the palest purple; the ten- 
tacula are pale yellow, shorter, and more slender in pro- 
portion than in vulgata. This species has been long known 
on the Devon coast as the China Limpet, from the rich 
Chinaware-like hue of the inside of the shell; whereas its 
congener has a far commoner and poorer aspect. These 
characters of the two are undeviating. They inhabit dit 
ferent levels, the vulgata being always in the higher zone. 
The athletica is very partially distributed hereabouts, being 
only found about four miles from Exmouth, in a very 
small area of an acre or two, where it is tolerably plentiful 
and exceedingly beautiful; very few of the common species 
are found along with it.” We have sought in vain for 
differences between the structure of the tongue in this and 
the common species. 

The species is probably generally, though locally, dis- 
tributed round our coasts. Captain Brown noticed it on 
the Northumberland coast in 1810, and Mr. Alder remarks 
that it is there rather rare, living on rocks close to low- 
water-mark, scarcely to be gathered but at spring tides. 
He adds that in some parts of England he has seen this 
Limpet range much higher up between tide-marks, and has 


* Dr. Knapp, however, has sent us specimens of the China Limpet from both 
Guernsey and Jersey, with the note that the animal is “always black or dark- 
coloured,” and on the Dorsetshire coast we find both dusky and yellow-footed 
individuals (E. F.). 


PATELLA. 429 


noticed on the southern coast an intermediate form between 
this and vulgata, which looks very like a hybrid: “the 
fishermen recognise the difference between them, and call 
this the Horse-limpet, rejecting it as too tough for bait.” 
This rejection of the animal as bait seems general ; in the 
little island of Herm, near Guernsey, the two species are 
never found mixed ; and poultry, which are there fed upon 
Limpets, turn from the athletica, whilst they greedily 
devour the common kind (S. H.). Dr. Johnston, in his in- 
teresting account of the Berwickshire Limpets, says that 
the fishermen distinguish these as ‘‘ Yawds,” and that they 
“have a tough leathery foot of a cream-yellow colour, and 
tentacula of the same colour, but a shade lighter. They 
are found near low-water-mark, and are said to be less 
common than the other varieties. They are almost worth- 
less as baits.” Lieut. Thomas informs us that the fishermen 
in the Orkneys make a distinction between the Limpets 
near high- and those near low-water-mark, and say that the 
fish will hardly take the first, when they will freely bite at 
the latter, which, if the low-water form be the species 
before us, is contrary to the usual observation. 


P. petiuctpa, Linneus. 


Not ribbed, smooth or nearly so, usually with radiating linear 
markings of blue or bluish green: margin quite entire. 


Plate LXTI. fig. 3, 4, and (Animal) Plate A.A., fig. 1. 


ListER, Hist. Conch. pl. 542, f. 26, 27. 
Patella pellucida, Linn. Syst. Nat. ed. 12, p. 1260.—PENN. Brit. Zool. ed. 4, 
vol. iy. p. 143, pl. 90, f. 150.—PuLrxEney, Hutchins, Hist. 
Dorset, p. 51.—Donov. Brit. Shells, vol. i. pl. 3, f. 1.— 
Mont. Test. Brit. vol. ii. p. 477. — Maton and Rack. 
Trans. Linn. Soc. vol. viii. p. 283.—Rack. Dorset Catalog. 
p. 58, pl. 23, f. 5.—Turr. Conch. Diction. p. 137.— 
FLEMING, Brit. Anim. p. 286.—Jounsron, Berwick. Club, 


430 PATELLIDA. 


vol. ii. p. 87.—Mace. Moll. Aberd. p. 182.—Brit. Marine 
Conch. p. 131.—Brown, IIl. Conch. G. B. p. 64, pl. 20, f. 2, 
3, 7, 8, 11.—Srrom. Acta Nidros. vol. iv. (1768).—Mit- 
LER, Zool. Dan. pl. 104, f. 1 to 4.Born, Testac. Mus. Cees. 
pl. 18, f. 9—CuEmn. Conch. Cab. vol. x. p. 330, pl. 168, 
f. 1620.—Ditiw. Recent Shells, vol. ii. p. 1042.—Lam. 
Anim. s. Vert. (ed. Desh.) vol. vii. p. 540.—Woop, Index 
Testac. pl. 37, f. 58.—Dzusu. Encye. Méth. vol. iii. p. 710.— 
SowerBy, Man. Conch. f. 230.—Hant. Conch. Book Spec. 
p. 6. 
Patella levis, PENN. Brit. Zool. ed. 4, vol. iv. p. 143, pl. 90, f. 151.—Turv. 
Conch. Diction. p. 137 (not var. bimaculata)—FLeEm. Brit. 
Anim. p. 286.—Jounsron, Berwick. Club, vol. ii. p. 37.— 
Mace. Moll. Aberd. p. 182.—Ditiw. Recent Shells, vol. ii. 
p- 1043 (not var.) 
Blue rayed limpet, Humvureys and Da Cos. Nat. Hist. Shells, pl. 4, f. 4. 
Patella ceruleata, DA Costa, Brit. Conch. p. 7, pl. 1, f. 5, 6. 
»  Oimaculata (younG), Monv. Test. Brit. vol. ii. p. 482, pl. 13, f. 8.— 
Maron and Rack. Trans. Linn. Soe. vol. vii. p. 235. 
ceérulea, Mont. Test. Brit. Suppl. p. 153.—FLem. Edin. Encycl. pl. 204, 
f. 1.—Forpzs, Malac. Monens. p. 36, animal.— Brown, IIl. 
Conch. G. B. p. 64, pl. 20, f. 13.—Woop, Index Test. pl. 37, 
fig. 59. 
» elongata and elliptica, FLem. Encyce. Edin. pl. 204, f. 2, 3. 
» cornea, Porinz and Micu. Gal. Douai, Moll. p. 525, pl. 37, f. 5, 6. 
Acmea pellucida, Brit. Marine Conch, p. xxxii. 


”° 


The two varieties of this elegant Limpet differ so re- 
markably from each other, as strikingly to illustrate the 
effects of food and habitat upon colour and solidity. The 
more typical pellucida feeds upon the leaves of the Fwez, 
the aberrant Jevis upon the roots and stalks, in which in- 
deed it is wont to imbed itself. The former is thin, semi- 
transparent, of a dark olive when adult, of an ochraceous 
yellow when young, is regular in shape, which ranges from 
subelliptic to rounded ovate—for, as in most Limpets, the 
shape tapers a little behind—and is adorned with more 
or less interrupted linear rays of lustrous Mazarine blue, 
that vary greatly both as to number and approximation. 
The latter form is a much stronger shell, very irregular in 


shape, yet generally pinched up, as it were, at the sides 


PATELLA. 431 


(so that when placed upon a level surface, the side mar- 
gins alone touch it), of a yellow or ochraceous horn colour, 
with the blue rays often all but wholly obsolete, and almost 
invariably of a lighter tint. In both states the interior 
has a tendency to iridescence, and the exterior is nearly 
smooth, having merely some obsoletely raised but numer- 
ous radiating strie, which for the most part are more 
conspicuous behind than in front, and some most minute 
and densely set concentric striule. In the more solid form, 
however, the internal opalescence is much more beautiful, 
and often exhibits a brilliant lilac or violet iridescence ; 
and the external sculpture, besides being more pronounced, 
has the stages of increase not unfrequently strongly indi- 
cated. The margin is entire; the vertex obtuse, and much 
reclined. 

The younger shells of the typical and undistorted form 
are much depressed ; the adult are conical convex; the 
more elevated the specimens the less marginal does the 
vertex become. In Jevis the dusky subinternal spot, 
which almost always lies beneath the vertex of the shell, 
is usually smaller, and is often nearly wholly absent. In 
the typical pellucida a short central linear ray of the same 
hue not unfrequently precedes this stain. We possess 
specimens nearly an inch long, but the average size of 
examples does not exceed two-thirds of that measurement. 

The animals of the two varieties are exactly alike in all 
essential characters, varying only in colour. We find that 
of levis usually white or yellowish; that of a well-grown 
pellucida, as taken in the Hebrides, usually orange. The 
comparatively greater exposure to light of the latter form 
may account for this difference. Mr. Clark has examined 
a very large series of the animal in all stages of growth, 


from the pellucida, only a one-twentieth to a quarter of an 


432 PATELLIDA. 


inch in length, and from thence to P. levis, of three- 
quarters of an inch long, and finds the organs similar in all 
respects, with a slight variation of colour dependent on 
age. 

The mantle is often bordered by a grey line, and is 
fringed with numerous (“fifty to sixty-five,” according to 
Mr. Clark) fine cirrhi which vary in length in different 
individuals. The branchie form a fringe of minute white 
plates between the foot and mantle, interrupted in front of 
the head, and terminated on each side nearly symmetri- 
cally. In a specimen three-fourths of an inch long we 
counted about a hundred branchial plates ; the hinder ones 
were longest. The head is rather large, terminating in- 
feriorly in a short proboscis, which has puckered edges, 
but is not emarginated below ; the tentacula are rather 
short, obtuse, and linear; they bear minute eyes on the 
outer sides of their slightly swollen bases. ‘ The foot is 
oval, very thick and dense, and the viscera are pale 
coloured ; the stomach from the pylorus gives forth a very 
long intestine, greatly convoluted between the lobes of the 
liver, which is light green (sometimes pale yellow, E. F.), 
and near the posterior end doubles and terminates as a 
rectum, accompanied by the oviduct a little to the right of 
the centre of the neck, under the right tentacle, not at the 
side of the body; the vent is double the size of the oviduct, 
which progresses from the oval, pale red brown minutely 
granular mass of the ovarium, placed immediately above 
the foot, at the posterior end” (Clark MSS.). The 
lingual ribband is not so long as in P. vulgata ; it is less 
than the length of the body; in a specimen nine-twelfths 
of an inch long, it measured seven-twelfths, and we counted 
eighty transverse series of teeth. Its axis is formed of four 
nearly equal teeth, with parallel sides, and hooked brown 


ACMAA. 433 


anterior terminations; at each side of each series is a broad 
brown tooth, tricuspid at its inner summit; outside of it 
is the first lateral, very broad, square, and colourless ; 
several colourless laterals follow. The jaws are tinged 
with dusky. 

This Limpet is found all round our coasts, wherever 
Laminaria grow. It ranges northwards to the Norwegian 
seas, and southwards to the shores of Gallicia. 


SPURIOUS. 


P. rvrorta, Donovan. 


Patella pectinata, Born (not Linnzus), Test. Mus. Cas. p. 423, pl. 18, f. 7.— 
Lam. Anim. s. Vert. (ed. Desh.), vol. vii. p. 539.— Brainy. 
Man. Malac. pl. 49, f. 5.—Drsu. Encycl. Méthod. vol. iii. 
p. 710. — Porizz and Micuaup, Gal. Douai, Moll. vol. i. 
1 Gxigre MAIS NPs 
»  imtorta, PENN. Brit. Zool. ed. 4, vol. iv. p. 143, pl. 90, f. 148 ?— 
Donoy. Brit. Shells, vol. v. pl. 146.—Maron and Rack, 
Trans. Linn. Soc. vol. viii, p. 231.— Monr. Test. Brit. 
Suppl. p. 154.—Turr. Conch. Diction, p. 136.—F.LEmine, 
Brit. Anim. p. 286.—Brit. Marine Conch. p. 130.—Ditiw. 
Recent Shells, vol. ii. p. 1037.—Woop, Index Test. pl. 37, 
f. 46. —SoweErsy, Genera Shells, Patella, f. 5—Krauss, 
Sud-Afrik. Conch. p. 57. 


A South African species (Natal, &e.); introduced by Donovan— 
for Pennant’s shell is too obscure for identification—as found on 
the western coast by Mr. Laskey. 


ACMA, EscuscHo.tz. 


Shell ovate, conical, with a subcentral anteal apex ; 
surface smooth or with radiating striations ; muscular im- 
pression crescentic or horse-shoe shaped, interrupted in 
the region of the head. 

Animal with two subulate tentacles bearing eyes on the 
outer sides of their swollen bases; mantle-margins fringed ; 


VOL. Il. 3) is 


434 PATELLIDA. 


branchie forming a pectinated plume lodged in a cervical 
cavity; foot large, ovate, with plain sides; buccal mass 
with cartilaginous jaws; lingual ribband long, copiously 
armed with teeth, three of which are borne obliquely on 
each half of each transverse series, the two halves forming 
distinct squares. 

This excellent genus was founded by Eschscholtz in 
1833, with a full understanding of both animal and shell. 
The latter can with difficulty be distinguished from that 
of Patella, an absence of a nacreous gloss on the upper 
surface being the chief difference. The group was consti- 
tuted by several authors almost simultaneously, so that it 
becomes difficult to determine whose name has priority. 
It appears to have been first indicated (but without a 
definition) under the name of Tectura by Audouin and 
Milne Edwards, who observed that the so-called Patella 
virginea had an animal presenting peculiarities of generic 
value at least. The ill-chosen name Patelloidea was given 
to it by Quoy and Gaimard, and Lottia by J. E. Gray. 

Several species of Acmea occur in both hemispheres. 
Some of them inhabit water of considerable depth. 


A. restupinaLis, Miller. 


Variegated with brown and white ; spatula-mark more or less 
painted with brown. 


Plate LXII. fig. 8, 9, and (Animal) Plate AA, fig. 2. 


Patella testudinaria, MULLER, Prodr. Zool. Dan. p. 237.—GMeEL, Syst. Nat. 

p- 3717 (var. Norveg.) 

»  testudinalis, MULLER, Prodrom. Z. D. p. 237, No. 2872. — Brit. Mar. 
Conch. p. 131. — O. Fasric. Fauna Grenland. p. 385.— - 
Bosc, H. N. des Coquil. vol. iii. p. 216.—Ditiw. Recent 
Shells, vol. ii. p. 1045. — Woop, Index Testac. pl. 37, f. 
63.—Desu. Lam. Anim. s. Vert. vol. vii. p. 543. 

»  tessellata, MULLER, Zool. Dan. No. 2868 (teste Beck). - 


ACMAA. 435 


Patella testudinaria Grenlandica, Cuemn. Conch. Cab. vol. x. p. 325, pl. 168, f. 
1614, 1615. 
Die Schildkroten-patelle var. b, KAMMERER (1786), Cab. Conch. Rudolst. p. 12, 
pl 2; f. 45.5: 
Patella Clealandi, SowErsy, Trans. Linn. Soc. vol. xi. p. 621.—FEmine, Brit. 
Anim. p. 287.—Mawk, Introd. Linn. Conch. pl. 32, f. 7. 
»  amena, Say, Journ. Ac. N. 8. Philadelph. vol. ii. p. 223. 
»  ¢lypeus, Brown, Ill. Conch. G. B. (edition without text), pl. 37, f. 9, 10. 
— Forsss, Mag. Nat. Hist. vol. viii. p. 592. 
Lottia testudinalis, Forbes, Malac. Monens. p. 34 (animal).— Brown, Ill. Conch. 
G. B. p. 64, pl. 20, f. 9, 10. — Gouxp, Invert. Massach. p. 
153, f. 12. 
Patelloida amena, Cournouy, Boston Journ. Nat. H. vol. u. p. 171. — Lua, 
Trans. Americ. Phil. Soc. (new ser.) vol. vii. p. 73.— 
Derxay, New York Fauna, Moll. p. 162, pl. 9, f. 196. 
Acmeea testudinalis, HANLEY, Brit. Mar. Conch. p. xxxii. f. 103. 


The little tortoise-shell Limpet has an oval or elliptic 
contour, is either depressed or depressed-conical, and has 
the surface flattish, and not convex, as in certain allied 
exotic species. The vertex, which is moderately inclined, 
is rather acute when not worn, and is more frequently 
pale-coloured than otherwise. The shell is generally thin, 
but not transparent, and is merely sculptured by very 
fine and extremely numerous crowded radiating strie, 
that are only slightly raised, a little undulating, and very 
densely, but almost invisibly, decussated by the extremely 
minute concentric wrinkles, that concentrically traverse 
the exterior. The painting is very elegant, the external 
pattern, which is very variable, being effected by a marbling 
or interlacement of rufous brown of various intensities, 
with a more or less impure white, so that either tint 
occasionally predominates. Frequently the brown forms 
a rather coarse network upon a pale ground, often it is 
disposed in very wavy and generally commingling streaks, 
or there is an union of both patterns on the same shell ; 
more rarely the surface is almost entirely brown, or white, 
with a few radiating brown lines. Within, the margin 


436 PATELLIDA. 


itself, which is rather flattened, exhibits the external 
colouring, and often presents an articulated appearance ; 
the spatula, or central mark, is more or less stained with 
brown, and the intermediate portion is enamelled with 
porcelain or bluish white. The edge is acute and quite 
entire. 

The animal is entirely white ; the margin of the mouth 
has considerable expansion, and is fringed with minute 
white cirrhi, which are quite inconspicuous when it is 
taken out of the water. The head bears two rather long 
and slender tentacula, having eyes at their internal bases. 
When the creature is active, the long lanceolate branchial 
plume is conspicuous, projected from its cavity on one 
side of the head, and extends some distance even beyond 
the shell. The disk of the foot is oval and very broad, 
and the sides quite plain and not steep. The tongue 
is long and is divided into a series of sections, each com- 
posed of two squares, the centres of which are of a bright 
yellow. On each square there are two conspicuous hooked 
teeth and a denticle, and the upper angles are produced. 

This Mollusk is a northern species of littoral habits, 
and does not make its appearance on the southern coasts, 
if indeed anywhere on the shores of England and Wales, 
though, as it appears to have a tendency to migrate 
southwards, it may be found hereafter considerably beyond 
the limits we here assign it. The locality ‘“ Bangor,” 
assigned to it by Mr. Sowerby, refers not to Bangor in 
North Wales, but to a place of the same name in the 
north of Ireland. On the Irish shores it has found its 
way as far south as Dublin Bay, in which well-searched 
district it has been noticed only of late years; it is there 
‘‘ abundant, near Williamstown, on stones above low- 
water-mark” (Hassall). It has appeared since 1836, and 


ACMA. 437 


multiplied considerably on the north coast of the Isle of 
Man (E. F.), and is not rare in the north-east of Ireland 
(W. Thompson). In Scotland it is more common, being 
abundant between tide-marks in many places in the Clyde 
district, and generally through the outer and inner He- 
brides (KH. F.). Mr. M‘Andrew has dredged it in four 
fathoms at Stornaway, and in twelve fathoms north of 
Shapinsha in the Orkneys, where Lieut. Thomas has 
found it also on the shores of Kirkwall Bay. 

It inhabits the coast of Norway, Greenland, and Boreal 
America. It is found fossil in pleistocene strata in 
Sweden. 


A. vireinra, Miiller. 


Small, rayed with pink (or reddish liver colour) and white ; 
spatula-mark not brown. 


Plate LXI. fig. 1, 2. 


Patella virginea, MU.Ler, Prodr. p. 237 ; Zool. Danic. pl. 12, f. 4, 5.— Mar. 
and Rack. Trans. Linn. Soc. vol. viii. p. 284.— Rack. 
Dorset Catalog. p. 59, pl. 14, f. 11.—Turr. Conch. Diction. 
p- 136.— Fiemine, Brit. Anim. p. 287.— Brown, IIl. 
Conch. G. B. p. 63, pl. 20, f. 1, 4, 6. -- Bosc, H. N. Co- 
quilles, vol. iii, p. 209. —- Ditiw. Recent Shells, vol. ii. p. 
1052.— Woop, Index Test. pl. 38, f. 81.—Dssu. Lam. 
Anim. s. Vert. vol. vii. p. 543. 
» parva, Da Costa, Brit. Conch, p. 7, pl. 8, f. 11.—Donoy. Brit. Shells, 
vol. i. pl. 21, f. 2.— Mowr. Test. Brit. vol. ii. p. 480; Suppl. 
p. 154. 
»  pulchella (yvouNG), Forbes, Mag. Nat. H. vol. viii. p. 591, f. 61.—Brit. 
, Mar. Conch. p. 132. 
2 Lottia pulchella (youNG), Forses, Malac. Monens. p. 34 (animal). 

os 25 x Browy, Illust. Conch. G. B. p. 64. 

»  virginea, AupER, Ann. Nat. H. vol. viii. p. 404.—Jounston, Berwick. 
Club, vol. ii. p. 34 (with animal). — Mace. Moll. Aberd. 
pemliine 

Aemaa virginea, HANLEY, Brit. Mar. Conch. p. xxxii. 

Patella equalis (Foss), SowERBy, Min. Conch. pl. 139. 

Tectura virginea (FOSSIL), SEARLES Woop, Crag Mollusca, pt. 1, p. 161, pl. 
18, f. 6. 


438 PATELLIDA. 


Like most Limpets, this elegant little shell is liable to 
a greater or lesser elevation of form and a corresponding 
alteration of the basal outline. In the more depressed 
individuals the latter is generally elliptical, and the vertex, 
which is always more or less anterior, is more inclined and 
advanced ; in the more conical examples it is rounded- 
oval, and the vertex is blunter and more central. The 
shell is more frequently thin and subpellucid than other- 
wise, and is never very glossy; it is not laterally compres- 
sed, but, on the contrary, rather inclined to spread at the 
sides. It is moderately arched behind, but is little convex 
elsewhere ; the anterior slope, for the most part, is more 
or less abrupt. The surface seems smooth, but when 
examined displays, besides the fine wrinkles of increase, a 
considerable number of obsoletely elevated, radiating lines. 
The exterior is prettily radiated with pink or reddish liver- 
colour upon a ground of greyish white or horn-colour, and 
in full-grown specimens exhibits, occasionally, but not com- 
monly, an additional kind of net-work in the paler portions, 
lines of the darker hue immeshing, as it were, numerous 
small and somewhat oval-shaped spots of the lighter tint. 
The rays are generally twelve or fourteen in number, and 
moderately broad; they are much more conspicuous to- 
wards the base, and, indeed, are generally obsolete upon 
the vertex. The inside, if not coated with a thin layer of 
porcelain white, faintly shows the external painting ; fre- 
quently two short rays of a dark red colour emanate from 
behind the vertex at acute angles to each other, so as to 
resemble the letter V truncated at its narrower extremity. 
The basal edge is quite entire, is rounded at both ends, and 
more or less arched on each side. Our larger specimens 
measure about five and a half lines in length, and four in 


breadth. 


ACMA. 439 


Young specimens from deep water are very tender, and 
have their red markings so disposed as to form monili- 
form rays on a bluish ground, which, when the creature 
is alive, appears even of a vivid blue colour. This is 
the condition to which the name Lottia pulchella was 
given. 

The animal of this pretty Limpet has attracted the 
attention of many observers, from whose notes, published 
and unpublished, and our personal observations, we are 
enabled to describe it at length. It is of a yellowish 
white colour, with the exception of the margin of the 
mantle, which is spotted with pink at intervals, correspond- 
ing to the rays of colour upon the shell. The mantle is 
bordered by tentacular filaments; these, Dr. Johnston has 
remarked, are placed about half a line within the margin, 
and are all directed inwards and towards the body: hence 
the discrepancies between the figures and descriptions of 
the animal, which has been represented and described as 
having the margin entire. On the sides of the head are 
the tentacula, long and subulate, swollen at their bases, 
on the outsides of which are placed the eyes. The tongue, 
according to Loven, differs from that of testudinalis, in 
having the anterior margins of the square transverse 
divisions entire and the three teeth on each square of 
more nearly equal dimensions, and placed regularly ob- 
liquely. The branchial plume, which has been carefully 
examined by Mr. Alder, is coarsely pectinated, and is 
often conspicuously exserted. The foot is oval and fleshy: 
Mr. Clark observes that there is a slight groove on the 
under part of its posterior extremity, and states that 
‘‘ when the ovarium discharges the membranous bag which 
contains the embryones, the posterior part of the foot serves 
as its nidus until such time as the young come forth from 


440 PATELLIDA. 


the membranous sac, when it throws off the empty films 
from its foot.” 

This Limpet is universally distributed around our coasts, 
adhering to shells and stones in various depths of water 
from the laminarian zone to as deep as twenty or 
thirty fathoms, most plentiful m from five to twelve 
fathoms, and occasionally, especially in the Hebrides, 
where it grows larger than in most places, occurring 
between tide-marks. It inhabits the Scandinavian and 
Celtic seas generally, and is found fossil in the red crag 


and northern drift. 


PILIDIUM, Forses and HAn.Ley. 


Shell ovate, conical, with an eccentric anteal apex; 
surface with radiating strie; interior with a crescentic 
muscular impression, interrupted in the region of the 
animal’s head. 

Animal with two subulate tentacles unprovided with 
eyes; mantle-margin simple; branchial plume cervical ; 
foot large, ovate, with plain sides ; lingual ribband com- 
posed of a single series of squares, on each of which a 
single trilobed tooth is borne, flanked on each side by two 
distinct accessorials. 

The eyeless head, even-edged mantle, and peculiarly 
constructed tongue of the Patella fulva of the Zoologia 
Danica forbid our associating it, as has been hitherto done 
by modern writers, with Acmaa, and demand for it the 
establishment of a peculiar genus. The shell so closely 
resembles that of Acmeaa, that from it alone the important 
differences presented by the animal could not be predicted. 
The only recorded living British species is found fossil in 


beds of coralline crag age. 


PILIDIUM. 4A] 


P. rutvum, Miller. 


Plate LXII. fig. 6, 7, and (Animal) Plate A. A. fig. 3. 


Patella fulva, Mister, Prod. p. 237 ; Zool. Dan. pl. 24, f. 1, 2, 3.—GMELIN, 
Syst. Nat. p. 3712.—Bosc, H. N. Coquilles, vol. iii. p. 209.— 
Ditiw. Recent Shells, vol. ii, p. 1053.— Woop, Index Testac. 
pl. 38, f. 83. 

>  orbesii, Smirn, Mem. Werner. Soc. vol. vii. p. 107, pl. 2, f. 3.— 
Brown, Illust. Conch. G. B. pl. 57, f. 3, 4. 
Acmea fulva, HANEY, Brit. Mar. Conch. p. xxxii. 
Tectura fulva, SEARLES Woop, Crag Mollusca, pt. i. p. 161, pl. 18, f. 7, a, b. 


This beautiful little shell is, both within and without, of 
a pure reddish orange colour, but varies in intensity of hue, 
as well as in occasionally being only rayed with orange 
upon a paler and more fulvous ground, although in general 
its tint is uniform. It is thin, depressed conical, and 
rather inequilateral. The vertex is by no means elevated, 
and is curved greatly forward, so that the descent from 
it anteriorly is rather abrupt, whilst the slope posterior- 
wards is gently arcuated: there is no particular lateral 
compression. The base is more or less elliptical, but rather 
broader behind, and rather more obtuse in front. The 
outer surface is adorned with minute radiating, elevated 
lines, which are numerous, but not closely disposed, and 
are rendered granular by the crowded decussation of still 
finer and almost microscopical lamellar lines. The basal 
margin is acute, and entire, or very nearly so. 

One of our largest specimens only measures a quarter of 
an inch in length, and but slightly exceeds two lines in 
breadth. 

The animal is white. Its head is not very large in pro- 
portion to the body, and terminates anteriorly and below 
in a short puckered muzzle. The tentacula are rather short 
for the tribe, and obtuse; they have swollen bases, but 

VOL, 11. 3.1L 


442 PATELLIDA. 


exhibit no traces of eye-spots. The mantle has its edge 
quite plain. The sides of the foot are not very steep, and 
the disk of that organ is oval. The branchial plume is 
not exserted when the animal is in motion. The tongue 
when moderately magnified presents the appearance repre- 
sented in our figure (Plate A A, fig. 3, b) as if it were 
composed of a series of square divisions, each with a 
bright yellow space in the centre, in front of which is a 
strong curved brown tooth flanked by two brown denticles, 
and bordered by uncoloured hooked teeth. A higher 
magnifying power shows that the uncoloured lateral teeth 
are accessorial (uncini of Loven). The teeth of the Nor- 
wegian ally, the Patella ceca of Miiller, present a similar 
arrangement according to Lovén, but exhibit important 
distinctions in detail. 

This mollusk was first announced as a member of the 
British Fauna by Mr. Smith, of Jordan Hill, who dredged 
it in the Clyde, off Arran. We believe it had previously 
been found (though not published) by Miss M. Ball 
adhering to a stone dredged from deep water on the 
coast of Ireland. It has since been taken on the west 
coast in fifty and sixty fathoms water off Cape Clear and 
Mizen Head (M‘Andrew). Adhering to a Pinna taken 
on the coast of Cork (J. D. Humphreys). It is not rare 
in the Clyde district, the Hebrides, and off the Zetland 
Isles, where it occurs in depths of water between twenty 
and eighty fathoms (M‘Andrew and E. F). In thirty 
fathoms twenty miles north of Kennard’s Head, Aberdeen- 
shire (Thomas). It mhabits the Norwegian seas, and is 
found fossil in the coralline crag. 


PROPILIDIUM. 443 


PROPILIDIUM, Forses anp Haney. 


Shell obovate, conical, with an eccentrie posteal apex ; 
surface with radiating strie; interior with a crescentic 
muscular impression interrupted in the region of the 
head. 

Animal with two subulate tentacles unprovided with 
eyes ; mantle-margin simple; branchial plume (two 
plumes?) cervical ; foot large, orbicular, with plain sides ; 
buccal mass with corneous jaws and a lingual riband, like 
those of Pilidium. 

We have constituted this genus for a very remarkable 
and rare mollusk, which, whilst its shell reminds us 
strongly of an Lmarginula without a slit and has a vertex 
holding the same position with respect to the head of the 
animal—an arrangement rarely seen among the Patellide— 
has its soft parts very similar in most respects with those 
of Pilidium. It presents considerable resemblance to 
some limpets referred to the genus Scufella, but not 
sufficient to permit us to refer it to that group. In 
Scutella Arabica there are two powerful muscular scars, 
one on each side of the interior of the shell, which seem to 
indicate differences of consequence in the animal. 


P. Ancytomwe, Forbes. 
Plate LXII. figs. 3, 4, 5, and (Animal) Plate A.A, fig. 4. 


2 Patella ceca, MtuLER, Zoolog. Danic. i. p. 45, pl. 12, f. 1, 2, 3, from which 
GEL. Syst. Nat. p. 3711, and Dixiw. Recent Shells, vol. ii. 
p. 1052. 
» 2 Ancyloides, ForBEs, Ann. Nat. Hist. vol. y. (1840) p. 108, pl. 2, f. 16. 
—Brit. Marine Conch. p. 133. 

2 4, candida, CourHovy, Boston Journ. Nat. Hist. vol. ii. p. 86, pl. 3, f. 17. 
— Gou_p, Invert. Massach. p. 152. — Dexay, New York 

Fauna, Moll. p. 161. 


444 PATELLIDA. 


2 Patella cerea, MOLLER, Index Moll. Grenland. p. 16 (=candida, teste Moller). 
2 4, 2exigua, ForBxEs, in Thompson’s Report, Brit. Assoc. Rep. for 1843, 
p. 259. 


It is possible, from the small size of the very few 
examples as yet taken, that this extremely rare Limpet 
may not have reached its full stature ; and that the shape 
and sculpture may not be precisely identical with that of 
the species when fully developed. Hence our description 
may not precisely correspond with some of the individuals 
which may hereafter be discovered: hence, too, our sus- 
picion that this shell may prove the immature state of the 
Patella ceca of Miiller. : 

The individual now before us is conical, thin, semi- 
transparent, a little oblique, somewhat laterally compressed, 
and of a pure white, both within and without. The basal 
margin has a rather elongated elliptical figure, is rounded 
and nearly equally broad at both ends, and is convex at the 
sides. The vertex is sharply pinched up, recurved, a little 
spiral, and subcentral, or rather before the middle of the 
shell; the slope from it forwards is at first arcuated, 
and then rather abrupt and but little convex; the slope 
posteriorwards is much more gradual, and, except imme- 
diately below the spire, is almost straight. The external 
surface, which is not polished, is densely covered with 
very delicate elevated radiating lines, that are concen- 
trically and closely decussated by equally fine imbricat- 
ing lamellar ones, which produces a fimbriato-granular 
appearance at the intersection of the two. The inner 
edge is nearly entire, or only subcrenulated by the external 
sculpture. 

The length of the individual above-described, is only two 
lines; examples of caca sent to us from Sweden, by our 
eminent friend, Professor Lovén, of Stockholm, of about 


PROPILIDIUM. 445 


twice the length, and quadruple the area, differed in the 
following respects, which may, probably enough, depend 
upon age. The shape was much more depressed, slightly 
broader, and not so pinched at the sides; the vertex was 
blunt, not at all spiral, and much less central. Near the 
margin the radiating granular striation was the only 
visible sculpture. 

The animal, which is of sluggish habits, is of a dingy- 
white colour, and not large in proportion to its shell. The 
head is turned away from the apex, and is rather small ; 
it is furnished with two rather short obtuse tentacles, 
which have no eyes upon their bases. The margin of the 
mantle is quite plain. The sides of the foot are narrow 
and the disk of that organ oval. There appear to be two 
short triangular branchial plumes in the neck-cavity; the 
cilia upon them are large. The tongue is very long, 
and the brown central spines conspicuous, under the 
microscope resembling bramble-thorns in miniature. 

Propilidium Ancyloide was added to the British Fauna 
by Mr. Smith, of Jordan Hill and one of the authors 
of this work when dredging in Lamlash Bay, in 1839. 
Since then we have taken it alive, in from thirty to ninety 
fathoms water, off the east coast of Mull; and, dead, in 
thirty fathoms, off Lismore (M‘Andrew and E. F.). It 
has also been found on the west coast, where it was 
“obtained by Mr. Hyndman, many years ago, on oysters 
from Strangford Lough” (Thompson). ‘‘ Two specimens, 
dredged alive off Ballantrae, Ayrshire, in 1842, were sent 
me by Mr. Edmund Getty. Dead shells are not un- 
common among comminuted nullipores dredged at Lamlash, 
Arran, in 1846, by Major Martin and the Rev. David 
Landsborough” (W. Thompson). 


446 


DENTALIAD. 


A.rnoucH we place the singular genus of Gasteropoda, 
which constitutes this family, in this place, as if it were a 
transition onwards from Patella to the fissurated Limpets 
—a position accordant with the view taken of its structure 
by Deshayes, who first decided on its molluscan nature,— 
we do so merely provisionally, and not without strong 
misgivings: for the account of the anatomy of Dentaliwm 
Tarentinum, just published by Mr. Clark, in the “ Annals 
of Natural History,” for November, 1849, throws so much 
new light on its structure, that it might have been better 
had we placed the group between Chiton and Patella. 

That the animal of the tooth-shell was not an Annellid, 
was first observed by the celebrated Savigny; that it was 
a true mollusk, was first determined by Deshayes, and that 
it should constitute a distinct order of Gasteropoda, to 
which the name of Cirrhobranchia was given, was first 
proposed by De Blainville. In the Memoir of Deshayes, 
communicated to the Natural History Society of Paris, 
in 1828, there is a very full account of the animal ; in 
some very essential particulars, however, the French and 
English malacologists are at variance. 

The shell of the Dentaliade is a cylindrical testaceous 
tube, open at both ends, the anterior orifice being much the 
wider. The animal is shaped like the shell, and so far as 
its characters may be regarded as of ordinal or family 


DENTALIADA. 447 


distinction, presents some remarkable features in important 
parts of its organisation. In the following summary of 
the characters of Dentalium, we have adopted the views of 
Mr. Clark, the more willingly since they appear to us to 
get rid of some anomalies recorded to exist in its structure, 
which rendered the creature’s affinities extremely dubious. 
The most essential differences between the two accounts 
relate to the respiratory and circulatory organs, and to the 
position of the vent. According to Deshayes, the branchize 
are grouped in the form of two tufts of long soft filaments 
with clavate extremities, one on each side of the animal’s 
neck. According to Mr. Clark, on the other hand, the 
branchie are “two symmetrical, sublateral, and somewhat 
post-centrally situated organs, having their bases fixed on, 
and hanging from, the concave surfaces of the animal, with 
their points vertically parallel to the bases; they are 
united at their inner surfaces by a bridle of branchial 
strands arranged symmetrically.” The latter observer 
finds the heart at the anterior end of the branchial cavity, 
and holds this peculiarity of position of that organ to have 
relation to the fact that the water, in this genus, flows to 
the branchie by the posterior aperture instead of in front. 
The organs taken for branchiz by Deshayes, are regarded 
by Clark as salivary glands, and the branchie of Clark are 
the lobes of the liver for Deshayes. As there appears to 
be a distinct liver in a more usual position, and as the 
relation of the circulation to the branchie has been clearly 
made out by the English naturalist, the usually accepted 


19) 


view of the “ cirrho-branchiate”” character of Dentaliwm 
becomes untenable. According to Deshayes, the vent in 
this genus is anomalous in position among the Gasteropods, 
being posterior; Clark finds the vent at the base of the 


branchial cavity, under the mantle, about the middle of 


448 DENTALIADA. 


the shell. For other points of difference and of detail, we 


refer our readers to the papers cited. 


DENTALIUM, Linnzus. 


Shell symmetrical, cylindrical, forming a long tube, its 
anterior orifice open, without constriction, to the greatest 
breadth of the shell, the posterior extremity attenuated 
and perforated ; surface smooth or annulated, or longitudi- 
nally ribbed or striated, or with decussating striz. 

Animal elongated, attached to the shell near its hinder 
extremity ; head rudimentary, eyeless, and without ten- 
tacles, cirrhated on the lip: mantle circular, thick and 
fleshy in front, thin posteriorly, capable of investing the 
entire frontal part of the body ; foot placed centrally and 
anteriorly, consisting of a pointed cone, flanked by two 
symmetrical side lobes, and mounted on a long pedicle, 
grooved on both surfaces, centrally hollow, the cavity com- 
municating with the stomach. Branchie and heart as 
already noticed. Sexes probably united. Main mass of 
the nervous system in the form of four nerve ganglions, 
connected to form a collar around the esophagus. Stomach 
furnished with a strong gizzard anteriorly, vent subcentral. 
Lingual membrane (according to Loven) broad, ovate, 
each section with a single-toothed rachis, flanked on each 
side by a single lateral. 

These mollusks are animal-feeders, devouring with 
avidity Foraminifera, and sometimes small bivalves. Mr. 
Clark has found species of as many as eleven distinct 
genera in the pouches on the two sides of the mouth, or in 
the stomach of D. Tarentinum. On the affinities of this 
genus, he remarks ‘the symmetrical subventral position 
of the branchie, the posterior flow of water to them, and 


DENTALIUM. 449 


the resemblance of the foot to that of some of the bivalves, 
combined with the similar character of its action, appear in 
a striking manner to show its connection with the Con- 
chiferee ; whilst by its esophageal cerebral ganglions, and 
completeness of the circulation, it has established its claims 
as a Gasteropod. There are also traces of alliance with 
some of the inferior classes; the red blood and vermiform 
configuration of the posterior part of the animal shows 
some of the characters of the Annelides.” * 

There are some shells which may readily be confounded 
with Dentalia. These are the testaceous tribes of Anne- 
lides, of the genus Ditrupa. A slight constriction around 
their orifices is usually an indication of their true nature. 


D. entrauis, Linn. 


Porcelain white, lustrous, not at all striated : posterior end 
emarginated. 


Plate LVII. fig. 11. 


Dentalium entalis, Linn. Syst. Nat. ed. 10, p. 785, and ed. 12, p. 1268, in part ; 
Fauna Suecica, ed. 2, p. 534.—Monr. Test. Brit. p. 494 Gn 
part only).— Maron and Rack. Trans. Linn. Soe. vol. viii. 
p. 237.—Turt. Conch. Diction. p. 37, 40.—Jounston, Ber- 
wick Club, vol. ii. p. 38, animal. — Macau. Moll. Aberd. 
p. 200.—Brit. Marine Conch. p. 1.—Brown, Illust. Conch. 
G. B. p. 117, pl. 56, f. 7 (probably). 


Worn individuals of the succeeding species have so 
generally been confused with the present one, that the 
earlier synonyms of this shell are of difficult determination. 

Linneus, in the tenth edition of his Systema, confounded 
the two species, but the expression “levi,” added in the 
twelfth, is more applicable to the northern shell. The 


* Clark in Annals Nat. Hist. ser. 2, vol. iy. p. 328. 


VOL. II. 3 M 


450 DENTALIADA. 


entalis of the ‘‘ Fauna Suecica” evidently, from its locality, 
belongs to the present species. 

The tube is subarcuated and sub-cylindraceous, the cur- 
vature at the broader end being only trifling, and the pos- 
terior attenuation in the majority of examples by no means 
rapid ; occasionally, however, this attenuation and arcu- 
ation is less gradual in its progress. The surface, which is 
nearly opaque and of a shining porcelain white, at times, 
though rarely, ringed with duller or even fulvous lines of 
growth, but never tinged with pink even at the narrower 
extremity, is perfectly free throughout from all sculpture 
whatsoever. The posterior termination has either a labial 
projection which is rather broadly fissured dorsally (i. e. 
upon the arched side of the tube) or if it bave not experi- 
enced that reparative process is then very tapering, and 
has a short shelving notch-like dorsal fissure; it is always 
entire upon the ventral or incurved side of the shell. In 
certain specimens the close approximation of the concentric 
lines of growth produce a somewhat annulated appearance. 

Mature individuals of twenty-two lines in length only 
measured a fifth of an inch at the broader end; whilst the 
diameter of the anterior extremity in a young and arcuated 
example only an inch long, was all but the sixth of an 
inch. 

Dr. Johnston has given a notice of the animal; ‘‘ the 
form is like that of the shell, round and tapering gradually 
to the posterior extremity; it is smooth, whitish, and closely 
invested with a thin pellucid membrane, beneath which two 
strong satiny ligamentous muscles are seen lying along the 
ventral surface, adhering closely, and each of them divided 
into a broad and a narrow slip * * *. The collar is very 
thick and fleshy, and makes a complete circle, through 
which the foot can be pushed at pleasure. The foot forms 


DENTALIUM. 451 


the anterior portion of the body; it is cylindrical, thick, 
fleshy, pointed with a conical process, and cleft below ; 
and in the groove we see the mouth in the shape of a com- 
pressed process, projecting forwards, and with its edge 
fringed with short tentacular papille.’* Mr. Clark re- 
marks that the branchiz of this species are of a paler green, 
more scanty, thin and delicate. 

It is found all round our coasts, and is especially 
abundant in the north. On the southern coasts of Eng- 
land it is rare, and its place is taken by the next species. 
It lives buried in sand or sandy mud in from ten to one 
hundred fathoms water; we have taken it most abun- 
dantly in from forty to seventy fathoms. On the coasts of 
the continent it ranges from Norway to Spain. 


D. Tarentinum, Lamarck. 


Sallow white, occasionally pink at the narrower extremity ; 
posterior end with fine longitudinal strize, not emarginated. 


Plate LVITI. fig. 12. 


Periver, Gazop. pl. 65, f. 9.—Ginannt, Opere Postum. pt. 
2; pl. 1, f. 2. 

Dentalium entalis, Linn. Syst. Nat. ed. 10 (in part).— PENNANT, Brit. Zool. ed. 
4, vol. iv. p. 145, pl. 90, f. 154 (probably). — PuLTENEY, 
Hutchins, Hist. Dorset, p. 52. — Monrv. Test. Brit. vol. ii. 
p- 494 (var.).—Rack. Dorset Catalog. p. 59, pl. 22, f. 10. 
—Lam. Anim. s. Vert. (ed. Desh.) vol. v. p. 595, in part. 
—Maweg, Linn. Conch. pl. 33, f. 5.—Drsu. Monog. Dental. 
(and in Mem. Soc, H. Nat. Paris, vol. ii.) p. 39, pl. 2, f. 2 
(and anatomy, pl. 1); Encyclop. Méth. Vers. vol. ii. pt. 2, 
p- 78, in part.—Puiiprr, Moll. Sicil. vol. i. p. 2435 vol. il. 
p- 206. — Penny Cyclop. vol, viii. fig. at p. 405. — REEvE, 
Conch. System. vol. vii. pl. 130, f. 3. — Cuxnu, Ill. Conch. 
Dental. pl. 2, and pl. 3, f. 2, c. 

vulgare, DA Costa, Brit. Conch. p. 24, pl. 2, f. 10. 


” 


* Trans. Berwick. Nat. Club, vol. il. no. 10, p. 39. 


452 DENTALIADA. 


Dentalium striatum, Mont. (not authors) Test. Brit. vol. ii. p. 492, and Suppl. 
p- 156 (probably). 
cf Tarentinum, Lam. Anim. s. Vert. (ed. Desh.) vol. v. p. 596.— HANL. 
Brit. Marine Conch. p. xvii. f. 6. — DELEs. Rec. Coq. 
pl. 1, f 4. 
a dentalis,* Torr. (not authors) Conch. Diction. p. 37.—FLeM. Edin. 
Encycl. p. 66. — Brit. Marine Conch. p. 2. — Brown, 
Illust. Conch. G. B. p. 117, pl. 56, f. 8. 
» labiatum, Turt. Conch. Diction. p, 38.—Brit. Marine Conch. p. 3.— 
Browy, Illust. Conch. G. B. p. 117, pl. 56, f. 4, 5. 
»  politum, TuRT. (not authors) Conch. Diction. p. 38. 
ne leve, Turt. Conch. Diction. p. 256.—Brit. Marine Conch. p. 3. 
5 entale (FOSSIL), SEARLES Woop, Crag Mollusca, p- 169, pl. 20, f. 2, a, b. 
The tube of this Dentalium presents much similarity to 
the preceding, but differs very essentially in the characters 
of its hinder extremity. It is strong, cylindraceous, com- 
paratively sudden in its attenuation, moderately arcuated, 
and of a nearly opaque and squalid white, cccasionally 
tinged with rose-colour at its narrower end, and sometimes 
variegated with ochraceous rings. The general surface is 
not highly polished but only moderately shining; it is 
smooth in the adult, but in the young, and towards the 
posterior termination of mature examples, fine, equal, and 
very numerous (about thirty) raised longitudinal striz are 
apparent, that, for the most part are narrower than their 
interstices, and are frequently preceded by, or intermingle 
with, very minute longitudinal striule, which are often 
visible when from the truncation, so common in this species, 
the terminal costellar striz are absent. The posterior end 
of the younger and middle-aged examples tapers to a very 
fine point, but never displays either fissure or emargination ; 
when excised, as it generally is in the adult, the reparative 
tube is very slender, all but entire, occasionally rather pro- 
duced, and never dilated at the extremity. 
The majority of specimens are much shorter than D, 


* The diagnosis of dentalis in the Linnean Transactions (vol. viii. p. 237), 
being copied from the “ Systema Nature,” does not apply to any British species. 


DENTALIUM. 453 


entalis, seventeen lines being above the standard length of 
the species in Great Britain. The broader end of an indi- 
vidual of that size measured the fifth of an inch. Worn 
shells may not unfrequently be separated from the pre- 
ceding species (which, by the bye, is peculiarly apt to 
display erosion at the narrower end) through the occasional 
appearance of an annular substratum of colouring matter at 
that extremity. A kind of articulated appearance is some- 
times produced through the strie being crossed by chalky 
rings of growth. 

An examination of the original types of Turton’s de- 
scriptions, most kindly forwarded to us by Mr. Jeffreys, 
has enabled us to determine the dentalis, labiatum, and 
politum (subsequently changed to deve) of that author with 
positive certainty. The first is the immature state, the 
second the truncated adult, with its reparative tube in 
perfection, whilst the third was constituted from dead and 
worn individuals of the last mentioned form. Mediter- 
ranean examples of Tarentinum are more elongated in 
proportion than the British ones, and their striae occupy 
a larger portion of the entire surface. 

As the name entalis more properly belongs to the 
northern shell, we have adopted that given by Lamarck to 
a variety of this species. Da Costa’s name of vulgare is 
certainly prior, but it was given with the idea of ejecting 
the Linnean name of a species that he considered at the 
same time to be identical with his own. The marked ill- 
will towards Linneus and his nomenclature so pertina- 
ciously displayed both in his conyersation and in his 
“ British Conchology,” arose from his bafiled desire of being 
admitted, through the influence of Linnzeus, to an honorary 
membership in a Swedish Natural-Historical Society.* 


* Smith’s Correspondence of Linnzus. 


454 DENTALIAD®. 


The animal is minutely described by Mr. Clarke in the 
valuable paper already cited, and the features we have 
mentioned in our notice of the characters of the genus are 
taken from his account of his species. It differs from the 
preceding in being of less slender form, of a yellowish white 
colour, instead of pure white, and possessing dark greenish 
brown, elongated, suboval branchie. 

This tooth-shell may be regarded as a member of the 
southern regions of the British Fauna, and, though not 
rare in many places, is on the whole a much more uncom- 
mon species than the last. It inhabits the sandy shores of 
Kent, Sussex, and Dorset (S.H.); ‘‘ the coralline zones 
of the South Devon coasts, five or six miles from land, in 
twelve to fifteen fathoms water” (Clark); Torbay (Alder) ; 
Ilfracombe (Miss Alder). Hast side of Lundy Island in 
from seven to twenty-five fathoms (M‘Andrew). Mr. W. 
Thompson, in his “ Report on the Irish Fauna,” indicates 
its presence in both east and west shores of Ireland; absent 
from the northern coasts. 

It ranges to the Mediterranean ; it is found fossil in the 


pleistocene tertiary at Bridlington. 


The D. gadus of Montagu, and the subulatum of the British 
Marine Conchology, are species of Ditrupa, and consequently 
belong to the Annelides ; Turton’s type of D. clawswm is merely 
a portion of a quill. 


SPURIOUS. 
D. semistriatum, Turton. 


Dentalium semistriatum, Turr. Conch. Diction. p. 39, f. 68.—Brit. Mar. Conch. 
p. 2. 

Notwithstanding that this species bears a marked resemblance 

to D. inversum, the absence of the characteristic and peculiarly 


DENTALIUM. 455 


seated fissure, evidences an essential distinction. We have 
compared the two specimens which belonged to Turton, with 
a perfectly fresh individual, in our own cabinet (the locality is 
unknown to us) ; and, although the finely tapering posterior ter- 
mination is uninjured, there is not the slightest appearance of 
any slit. This species is slender, semi-transparent, moderately 
arcuated, and of a pure white (stained, however, in one of the 
Turtonian examples, with pale red at the narrower extremity). 
It very slowly enlarges from the middle anteriorwards, so that 
the mouth is not at all dilated ; behind it tapers to a very fine 
point. Very numerous raised longitudinal lines, that are scarcely 
equal in breadth to their interstices, occupy about one-third of 
the shell at its lustreless hinder extremity ; the surface then 
becomes highly polished and smooth; but exhibits several obso- 
lete rings of growth, which prevent it from being quite ievel. 
The length of our own largest example was nearly one inch and 
a quarter; its breadth at the larger orifice barely exceeded the 
tenth of an inch. 


An exotic shell, said by Turton to have been taken in Dublin 
Bay. The D. semipolitum of Broderip and Sowerby (Zoolog. 
Journ. vol. iv. p. 369,) may possibly prove identical, as the only 
part of the very brief description which does not correctly apply, 2s 
the statement, that the stricee occupy one half of the shell. 


D. ocraneuLtatum, Donovan. 


Dentalium octangulatum, Donov. British Shells, vol. v. pl. 162.—Brit. Marine 
Conch. p. 2 (part only)— Brown, Illust. Conch. 
G. B. p. 117, pl. 56, f. 2. 
a octogonum, Lam. (ed. Desh.) Ania. s. Vert. vol. v. p. 591, (var.).— 
DrsH. Monog. Dent. p. 32 (pl. 2, f. 5, 6!) ; Encycl. 
Méth. Vers, vol. ii. pt. 2, p. 74.—SoweErsy, Zool. Journ 
vol. iv. p. 181.—Sowrrpy, Conch. Man. f. 2.—DELEs. 
Ree. Coq. pl. 1, f. 1.—CuEnu, Ill. Conch. Dental. pl. 1, 
£22, 
A striatulum, Turt. Conch. Diction. p. 38 (part only).— Mownr. Test. 
Brit. Suppl. p. 155. 
* aprinum, MAwe, (not authors) Linn, Syst. Conch. pl. 33, f. 1. 


An exotic species, said to be Chinese (?); introduced by Dono- 
van as taken on the sands of Cornwall. The diagnosis of striatu- 


456 DENTALIAD A. 


lum in the Linnean Transactions (vol. viii. p. 238,) being taken 
from Gmelin, does not apply to any supposed British species. 
Turton in his description, confounds the D. aprinum (of Deshayes 
Monograph) with this shell. 


D. vartapnite, Deshayes. 


Dentalium eburneum, Turton, Conch. Diction. p. 37. 

album, Turton, Conch. Diction. p. 256.—Brit. Marine Conch. p. 2. 

variabile, DusH. Monog. Dental. p. 32 (pl. 2, f. 30!); Encyclop. 
Méth. vol. ii. pt. 2, p. 75.—Sowersy, Zool. Journ. vol. 
iv. p. 182. —M. Epwarps, Lam. Anim. s. Vert. (ed. 
Desh.) vol. v. p. 592.—CuHeEnvy, Ill. Conch. Dentalium, 
pl. 1, f. 27, 28, 29 (probably). 


” 


99 


An exotic species, said to be Hast Indian ; introduced by Turton 
as not uncommon on the western coast! The name of album must 
succumb to the subsequent one given by Deshayes, since the descrip- 
tion, which is by no means good (indeed without the types we 
could not have determined the species), is neither in Latin nor 
accompanied by an ulustrative drawing. 


457 


CALYPTRAID. 


Tuts group of Limpets consists of animals which have a 
patelliform shell, with an expanded and entire mouth, and 
an apex which exhibits more or less of a spiral conformation. 
The interior is either quite open or divided by a variously 
shaped shelly process. The animal has a distinct head 
and tentacula, the eyes being placed on the external bases 
of the latter organs. The muzzle is sometimes lengthened, 
but there is no true proboscis. The branchial plume is 
single. The tongue is studded with teeth ranged in rows 
of seven, that in the centre differently formed from the 
hook-shaped laterals. This dentition is very different from 
what is seen in the neighbouring tribes, and seems to 
indicate affinities with Velutina and other distant genera, 
which cast some doubts on the true position of the group. 
The foot has never any cirrhi ornamenting the sides. 

In our seas there are but very few members of this 
family ; in tropical regions they are numerous and greatly 
varied. 


PILEOPSIS, Lamarck. 


Shell conical, entire, dilated at the aperture, and having 
the vertex, which is posteal, slightly recurved ; outer sur- 
face usually striated, and invested with a corneous epi- 
dermis: interior with a horse-shoe muscular impression, 


VOL, II. 3 .N 


458 CALYPTRAIDA. 


interrupted in the region of the head; no internal par- 
tition. 

Animal with a head produced into a_proboscidiform 
muzzle; tentacula two, long, subulate, unconnected, with 
the eyes or bulgings at their external bases ; mantle fringed 
at the margin ; branchial plume single; foot strong, sub- 
orbicular, its sides plam. ‘Tongue rather long with a 
cordate membranous border at its anterior extremity ; 
lingual teeth (according to Loven) arranged in transverse 
series of seven, of which the central one is small and broad 
with a hooked apex, and the others long and hamate. 

The shells of this genus are the most patelliform of their 
tribe, and resemble little caps of liberty. The animal is 
rather sluggish and sedentary, and sometimes secretes an 
imperfect shelly disk from its foot ; hence it has been com- 
pared with Hipponyx. The group is a very ancient one, 
dating even to paleozoic times, and apparently extending 
its range to the oldest fossiliferous rocks. Acrocutta, of 
Phillips, founded for some of these ancient forms of 
Piteopsts, scarcely differs generically. We have preferred 
using the name given by Lamarck to that of Caputus 
given by De Montfort, under the conviction that priority 
alone cannot be admitted as sufficient ground for the adop- 
tion of a generic appellation in Malacology, since in that 
case appellations given by ignorant dealers or authors, 
who, like Perry, did not even pretend to science, or such 
random and worthless empirics as De Montfort was, will 
have too often to be preferred before the nomenclature 
resulting from earnest and scientific study. Specific appel- 
lations had best be as often as possible determined by right 
of priority, since though the original description or figure 
might be bad, there was still the recognition of a distinct 
object on the part of the founder; but the establishment of 


PILEOPSIS. 459 


a genus is entirely a matter of judgment, and though for 
convenience we may refer generic names to those who first 
proposed them, we cannot hold ourselves in justice bound 
to adopt any name without reference to the understanding 
on the part of its originator of its generic value. 


P. Hunearicus, Linneus. 


Plate LX. fig. 1, 2, (as Capulus H.) and (Animal) Plate C.C, fig. 3. 


Patella Ungarica, Linn. Syst. Nat. ed. 12, p. 1259. — Putrenry, Hutchins, 
Hist. Dorset, p. 51. — Monr. Test. Brit. vol. ii. p. 486.— 
Maron and Rack. Trans. Linn. Soc. vol. viii. p. 280.— 
Rack. Dorset Catal. p. 58, pl. 23, f. 7.— Turr. Conch. 
Diction. p. 140, f. 76. — Born, Test. Ces. Vind. p. 421, 
vign. at p. 414, fig. d.— Bosc, Hist. Nat. Coquilles, vol. iii. 
p- 206, pl. 25, f. 2. — Brooxzs, Introd, Conch. (1815), f. 
125.— Ditiw. Recent Shells, vol. ii, p. 1034, — Woop, 
Index Testac. pl. 37, f. 41. — Mawes, Linn. Conch. pl. 32, 
f, 2. 
»  Lepas, &c. Martini, Conch. Cab. vol. i. p. 143, pl. 12, f. 107, 108. 
» Hungarica, PENNANT, Brit. Zool. ed. 4, vol. iv. p. 143, pl. 90, f. 147.— 
Donovy. Brit, Shells, vol. i. pl. 21, f. 1. 
s5  pileus morionis major, Da Cosra, Elem. Conch. p. 12, pl. 1, f. 7. 
Large Fool’s-cap Limpet, Humrureys and Da Cosra, Nat. Hist. Shells, pl. 4, 
f. 18. 
Pileopsis Ungarica, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 609. — Turr. 
Zoolog. Journ, vol. ii. p. 566.— Brit. Marine Conch. p. 
135. — Brown, LIllust. Conch. G. B. p. 60, pl. 20, f. 19, 
20.—Croucu, Introd. Lam. Conch. pl. 14, f. 4.—Dzsu. 
Encycl. Méth. vol. ii. pt. 1, p. 153. — Puiipri, Moll. 
Sicil. vol. i. p. 118, and vol. ii. p. 91.— REEVE, Conch. 
Syst. pl. 146. 
Amalthea maxima, SCHUMACHER, Syst. Test. (1817), p. 182. 
Capulus Ungaricus, SowERBY, Genera Shells—Sowrrsy (Jun.) Manual Conch. 
f, 240. 
» Hungaricus, FLEMinNG, Brit. Anim. p. 363.—Forszs, Malacol. Monens. 
p. 33 (animal).—Jounston, Berwick Club, vol. ii. p. 33. 
— Mace. Moll. Aberd. p. 332.—Gray, Ency. Metrop. 
Moll. pl. 4, f. 13, 14.—Lovin, Index Moll. Scandinay, 
p- 16 (Animal). 
Pileopsis Hungarica, Cuvier, (ed. Croch.) Regne Anim. pl. 47, f. 7. 
5 antiquata (vouNG), Coucn, (not authors), Cornish Fauna, p. 44 (from 
type). 
Capulus milituris, Mace. Moll. Aberd, p. 333 (teste Jeffreys, from type). 


460 CALYPTRAIDA. 


The Fool’s-cap Limpet, as it is familiarly called, was, 
from its peculiarity of form, one of the earliest species 
recognised by the British collector. Modifying its shape 
according to the peculiarities of its habitat, it is by no 
means symmetrical; its general outline, however, is sub- 
conical, or if viewed laterally, semicordate, reminding us 
forcibly of one of the valves of an Jsocardia. It is 
tolerably strong, but not solid, rather transparent for its 
thickness, and under its drab or ashy brown pilose epi- 
dermis, which is sometimes dull and shaggy, sometimes as 
smooth and glossy as satin, is either pale flesh-coloured or 
white ; in the latter case usually more or less tinged with 
yellow, in the former frequently stained internally with 
various intensities of crimson. The surface, which is often 
disfigured by irregular indentations, besides distant wrinkles 
of increase, is everywhere marked with simple rounded 
coarse raised striz or narrow costelle, whose interstices are 
of about the same breadth with them, and are unsculp- 
tured, except by such still narrower complementary costelle 
as the gradual widening of the interstices demand. The 
vertex is spiral, a little inclined to one side, but only at its 
termination, where the rapidly attenuated whorls, if not 
loosely coiled, are only visible on one side; the penult 
whorl is always disunited from the shelving pillar-lip, and 
rarely, if ever, descends to its level. The inside is smooth, 
shining, more or less circular in marginal outline, and 
either white or stained with rose or a pinkish flesh-colour ; 
the rim is not crenated. 

The bases of some of our larger specimens measure only 
an inch and a half, and their height is one-third less, yet 
occasionally, and especially in foreign examples, these 
dimensions are greatly exceeded. Montagu mentions one 
from Salecomb Bay in Devonshire of two inches in diameter, 


PILEOPSIS. 461 


and there are specimens of equal size in the cabinet of 
Mr. Jeffreys. 

The animal is white or yellowish, its mantle pinkish-white 
or red colour, bordered by a fine bright yellow or orange 
fringe; the head is prominent, tumid, and produced in 
front into a proboscidiform muzzle, cloven at the extremity, 
and often tinged with brown: on each side of the head is a 
long, subulate, white or yellowish tentacle, bearing the eyes 
on a prominent bulging near the external base. The foot is 
stout, fleshy, and sub-orbicular, with plain sides; in front 
it is bordered by a slightly scalloped membrane. 

This mollusk is generally distributed around our shores ; 
though sparingly in most places. It is most abundant on 
the south coast of Devon, where the name of ‘ ‘Torbay 
Bonnet” is applied to it (S. H.), and in the Irish Sea 
around the coasts of the Isle of Man. It chiefly inhabits 
rocky ground, and oyster and scallop banks, adhering to 
shells, living in various depths of water from fifteen to as 
deep as eighty fathoms, and extending its range to con- 
siderable distances from land. It is finest in from fifteen 
to twenty-five fathoms, and usually small in very deep 
water. 

It ranges from the coast of Norway to the Mediter- 
ranean, and as a fossil dates its existence within our area 


from the epoch of the coralline crag. 


SPURIOUS. 


P. mimuraris, Linneus. 


ListreR, Hist. Conch. pl. 544, f. 11. 
Patella militaris, Linn. Mantissa, p. 552 (probably).— PuLTENey, Hutchins, 
Hist. Dorset, p. 51.— Monr. Test. Brit. vol. ii, p, 488, 
pl. 13, f. 11.—Donov. Brit. Shells, vol. v. pl. 171.— 
Mar. and Rack. Trans. Lin. Soe. vol. vil. p. 231.—Rack. 


462 CALYPTRAIDA. 


Dorset Catalog. p. 58, pl. 22, f. 7.—Turr. Conch. Diction. 
p- 140.—Ditiw. Recent Shells, vol. ii. p. 1035.—Woon, 
Index Test. pl. 37, fig. 42. 

Small Fool’s-cap, HuMeureys and Da Costa, Nat. H. Shells, pl. 4, f. 10. 

Patella spirata, HELBLING, Abhand. Privat. Bohmen, vol. iv. (1779) pl. 1, 

fees 

Pileopsis intorta, Lam. Anim, s. Vert. (ed. Desh.) vol. vii. p. 610.— Desu. Enc. 
Méth. vol. ii. pl. 1, p. 154. — Poriez and Micu. Galerie 
Douai, vol. i, pl. 36, f. 9, 10.—HANnL. Conch. Book of Spec. 
p. 12, f. 13. —DetessrerT Rec. Coquilles, pl. 25, f. 1. 

Capulus militaris, Fleming, Brit. Animals, p. 364. 

»  tortus, BLAInv. Malac. pl. 49 bis, f. 1. 
Pileopsis militaris, Brit. Marine Conch. p. 135.—Putmrrrt, Moll. Sicil- vol. ii. 
p- 92 (probably). 


A West Indian shell ; introduced by Pulteney as a Dorset 
species. 


P. antiquata, Linneus. 


LisrER, Hist. Conch. pl. 544, f. 31.—K.E#IN, Ostrac. pl. 8, f. 11, 12. 

Patella antiquata, Linn. Syst. Nat. ed. 12, p. 1259. — Pu.tEnery, Hutchins, 
Hist. Dorset, p. 51.— Monr. Test. Brit. p. 485, pl. 13, f. 9.— 
Turt. Conch. Diction. p. 39.—Ditiw. Recent Shells, vol. 
ii. p. 1035. 

Lepas, &¢., Marini, Conch. Cab. vol. i. p. 146, pl. 12, f. 111, 112. 

The Cap, Humenur. and Da Cos. Nat. Hist. Shells, pl. 4, f. 6. 

Patella mitrula, GMEL. Syst. Nat. p. 3708.—Mar. and Rack. Trans. Linn. 
Soe. vol. viii. p. 230.—Rack. Dorset Catalog. p. 58, pl. 22, 
1 (es 

Capulus antiquatus, FLEMING, Brit. Animals, p. 364.—Brit. Marine Conch. p. 

135.—Macravrin, Berwick Club, vol. ii. p. 40. 

Pileopsis mitrula, Lam. Anim, s. vert. (ed. Desh.) vol. vii. p. 610.—Gray, 
Encyclop. Metropolitana, Moll. pl. 4, f. 13, 14. — Dzsu. 
Encyc. Méthod. Vers, vol. ii. pt. 1, p. 154. 

Hipponyx mitrula, Proc. Zoolog. Soc. 1835, p. 5 (probably). 


A native of the West Indies ; introduced by Dr. Pulteney as 
From the shores of Dorsetshire. 


CALYPTRAA. 463 


CALYPTRAZA, Lamarck. 


Shell conical, entire, depressed, subspiral, with a central 
vertex ; surface smooth, or scaly; interior with a par- 
tition. 

Animal with a broad and slightly produced muzzle ; 
tentacula two, rather short, lanceolate, unconnected, with 
the eyes on bulgings at their external bases; mantle with a 
simple edge: branchial plume single; foot suborbicular, 
slightly angled in front, its sides plain. Tongue constituted 
like that of Pileopsis (?) 

This is a southern and tropical genus, of which the 
only species inhabiting our seas is one on the very bounds 
of the region inhabited by the tribe. In tropical seas 
the forms of Calyptrea are very curious and varied. 
Unlike P2leopsis, the group is of comparatively recent 
origin, beginning, at earliest, during the later secondary 
epoch, and multiplymg as it approached the present 
era. 


C. Stvensis, Linneeus. 
Plate LX. fig. 3, 4, 5, and (Animal) Plate B.B, fig, 8 to 13. 


Humpu. and Da Cos. N. H. Shells, pl. 6, f. 11, 12.—Born, 
Testac. Mus. Ces. Vind. p. 414, vign. fig. e. 
Patella Chinensis, Linn. Syst. Nat. ed. 12, p. 1257. — Monr. Test. Brit. vol. ii. 
p- 489, pl. 13, f. 4. — Maron and Rack. Trans, Linn. Soc. 
vol, viii. p. 228.—Turv. Conch. Diction. p. 134, f. 29, 30. 
»  albida, Donovan, Brit. Shells, vol. iv. pl. 129. 
»  Stnensis, Dintw. Recent Shells, vol. ii. p. 1017.—Woop, Index Testac. 
pl. 37, f. 4. 
Calyptrea levigata, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 623. 
Trochita Chinensis, SCHUMACHER, Syst. Vers, Testac. (1817), p. 184. 
Calyptrea Chinensis, FLEMING, Brit. Animals, p. 362. — Brit. Marine Conch. p. 
136. —S. Woop, Crag Mollusca (fossil), pl. 18, f. 1, 
a—e. 


464 CALYPTRAID. 


Calyptrea Sinensis, Desu. Ann. Se. Nat. vol. iii. (1824), p. 335, pl. 17, f. 1, 2; 
Encyel. Méth, vol. ii. p. 175.— Brown, Illust. Conch. 
G.B. p. 60, pl. 20, f. 16, 18. 
Patella muricata, Costa, Moll. Sicil. p. 124. 
ss vulgaris, Puiiipri, Moll. Sicil. vol. i. p. 119, and vol. ii. p. 93. 
Infundibulum rectum (Fossi1), J. SowERBY, Min. Conch. pl. 97, fig. 3. 
aA Sinense (Fossit), Morris, Cat. Brit. Fos. p. 148. 


This delicate shell is thin, semi-transparent, and of an 
uniform white both within and without. It is nearly 
circular at the base, is depressed-subconical, and has the 
vertex nearly central, tapering to a small point, and 
rapidly subspiral. The outer surface is rather dull, and 
either almost smooth, or closely set with small very thin 
and caducous vaulted scales, which latter is probably the 
normal state, and the frequent smoothness the mere result 
of abrasion. No other sculpture is obvious, but the lines 
of growth are often strongly indicated. The interior is 
highly polished, and has the margin perfectly entire; 
there is a remarkably fragile broad septum, which runs 
obliquely and spirally from under the vertex, so as to 
cover over about one fourth of the area of the lower 
disc. This septum, which is more or less concave, and 
only marked with the lines of growth, is attached to 
the side of its arcuated outer edge, and is free and much 
incarved at its inner edge, which latter is strengthened 
by a more copious deposition of shelly matter, and 
forms a kind of pseudo-columella: the terminal edge of it 
is convex, and very nearly reaches to the basal level. The 
diameter of the base rarely exceeds three quarters of an 
inch. 

The animal is yellowish, or fawn white, with opaque 
dots. The head is not very prominent, and is short, 
terminating in a cleft or bilobed muzzle. On each side 


of it is a thick cylindric rather short tentacle, bearing the 


CALYPTRAA. 465 


eye on a bulging near the outer base. There is a slightly 
developed semicircular, plain-edged, fleshy lobe on each 
side of the neck. The mantle is single-edged, without 
any trace of a fringe, and broader at one side than at 
the other. In the cavity behind the head is seen the 
pectinated branchial plume, the divisions of which are 
long, linear, and rounded at their ends. The foot is 
circular, with slightly produced angles on each side in 
front. The tongue is rather broad and colourless. 

This Mollusk lays its spawn on stones and old shells. 
The spawn is enveloped in bundles of fimbriated colourless 
membrane, the edges of which appear white or yellow 
owing to the included genus. The fry have a helicoid 
shell, rather large eyes on the bases of short triangular 
tentacles, and large ciliated neck lobes. Mr. Alder has 
observed the Oalyptrea to carry and hatch its spawn 
under the neck in front of the foot, and a similar habit 
has been noticed by Mr. Clark in Pileopsis Hungaricus. 
A Calyptrea, which we kept in confinement, swallowed 
a Goniodoris nodosa preserved in the same vessel. 

This is essentially a southern British shell. It is 
abundant in Jersey (S. H.) and Guernsey (Barlee) ; we 
have taken it in Dartmouth reach in seven fathom water 
(M‘Andrew, and E. F.); Plymouth (Jeffreys) ; Salcombe 
(Alder, Barlee); Falmouth (Cocks); Fowey (Peach, 
Alder); Milford Haven in ten fathoms, apparently its 
northernmost limit on the English coast (M‘Andrew) ; 
‘“‘on the east coast of Ireland” (Thompson). 

It does not range north of Britain, but southwards 
extends to the Mediterranean. As a fossil it dates back 
to the coralline crag. 


VOL. II. 3) © 


466 CALYPTRAID A. 


SPURIOUS. 


CrEPIDULA UNGUIroRMIs, Lamarck. 


Patella crepidula, Linnzvs, Syst. Nat. ed. 12, p. 1257. 

Crepidula unguiformis, LAM. Anim. s. Vert. (ed. Desh.) vol. vii. p. 642 (pro- 
bably).— SowrrsBy, Genera Shells, Crep. f. 6.— Pur 
uipPi, Moll. Sicil. vol. i. p. 94.—Brop. Proc. Zool. 
Soc. 1834, p. 39; Trans. Zool. Soc. vol. i. pl. 29, f. 4. 
—REEVE, Conch. Syst. pl. 143, f. 6. 

os plana, SAy, American Conch. pl. 44.—-Gouxp, Invert. Massach. p. 
158, f. 16.—Drxay, New York Fauna, Moll. p. 158, pl. 7, 
1% ISB} 
stnuosa, TuRT. Zool. Journ. vol. ii. p. 364, pl. 13, fig. 5. —FLEMING, 
Brit. Animals, p. 363. 

candida, Risso, Hist. Nat. Europe Mér. p. 255, f. 138. 

calceolina, DESHAYES, Encycl. Méth. Vers, vol. ii. pt. 2, p. 26. 

Protea, var. D’ORBIGNY, Voy. Amer. Mérid. p. 465. 


A native of North America ; introduced into our Fauna by 
Turton, from having been found at Scarborough attached to the 
bottom of an American vessel. It is precisely the plana of Say, 
from which the unguiformis of the Mediterranean does not seem 
essentially distinct : the latter is the Patella crepidula of the Lin- 
neean cabinet. 


467 


FISSURELLID. 


Tue passage from the Limpets to completely spiral uni- 
valves, is very naturally maintained by the members of this 
family, all of which are remarkable for some solution of 
continuity in the shell, either a perforation or a slit in the 
region of the vent, and with reference to the construc- 
tion of that organ, though often spoken of by conchological 
writers as if it were a branchial orifice. The form of 
their shells is more or less conical, with indications of 
a rudimentary spire at the apex, which often disappears 
with advancing age. The animals have well developed 
heads, with short muzzles, and subulate tentacles, at the 
external bases of which are the eyes placed on rudimentary 
pedicles. Between the sides of the foot at the mantle 
is a range of short lateral cirrhi. These characters of 
peduncated eyes and cirrhated sides indicate a close 
approach to the Trochide and Haliotidee, an indication of 
affinity which is fully borne out by the arrangement of 
the lingual teeth. There are two symmetrical branchial 
plumes. 

The genera are distinguished from each other by the 
characters of the mantle and the disposition of the vent, 
both of which affect materially the form and characters of 
the shell, consequently the family is composed of groups 
equally well defined, conchologically and malacologically. 
All its members are marine, some littoral, some inhabiting 


468 FISSURELLID&. 


considerable depths. They are distributed through the 
seas of all climates. 


FISSURELLA, Brucuiere. 


Shell conical, usually thick and depressed, the vertex of 
the adult truncate and perforate, and placed on the shorter, 
which is the anterior portion of the shell ; aperture widely 
expanded, oblong ; surface with radiating, often cancellated, 
strie or ribs. Interior without any partition ; muscular 
impression elongate, crescentic, interrupted in the region of 
the head. 

Animal with a short muzzle, terminating a tumid head, 
bearing two subulate tentacles, at the external bases of 
which are the eyes, placed on rudimentary pedicles; a 
range of numerous cirrhi around the sides at the base of 
the very large foot; mantle produced in front, with a 
fringe of cirrhi above its margin; anal siphon in the form 
of a short, truncated, membranous canal, projecting from 
the apical aperture of the shell; branchial plumes two. 

The fry of this genus has the vertex of the shell entire 
and subspiral ; the perforation at that stage assumes the 
position which we see it permanently take in Rimula and 
Puncturella. The species of Missurel/a are numerous, often 
large and handsome, and mostly inhabitants of tropical 
seas. But few are known in the fossil state. The majority 
of living ones inhabit shallow water. They are popularly 
known as Key-hole Limpets, on account of the peculiar 
shape of the apical orifice. 


eS UT ee ae 


FISSURELLA. 469 


F. rericutata, Donovan. 


Plate LXIII. fig. 4, 5, and (Animal) Plate B.B. fig. 7. 


Patella Greca, PENNANT, Brit. Zool. ed. 4, vol. iy. p. 144, pl. 89, f. 153.— 
Putreney, Hutchins, Hist. Dorset, p. 52.—Monv. Test Brit. 
vol. ii. p. 492.—Maron and Rack. Trans. Linn. Soe. vol. viii. 
p. 236.—Rack. Dorset Catalog. p. 59, pl. 23, f. 3.—Turrt. 
Conch. Diction. p. 141, f. 82 (badly).—Donoy. in Rees’ En- 
cyel. (1811) Conch. pl. i. bis?.—Brooxss, Introd. Conch. f. 
123.—Dituw. Recent Shells, vol. ii. p. 1056 (chiefly).— 
Woop, Index Test. pl. 38, f. 91. 
» larva reticulata, DA Costa, Brit. Conch. p. 14, pl. 1, f. 3. 
» reticulata, Donov. Brit. Shells, vol. i. pl. 21, f. 3. 
» apertura, (Fry) Mont. Test. Brit. p. 491, pl. 13, f. 10.—Maron and 
Rack. Trans. Linn. Soc. vol. viii, p. 286.—Turt. Conch. 
Diction, p. 141, f. 82.—Lowe, Zool, Journ, yol. iii. p. 77. 
Fissurella cancellata, GRAY, Annals Philosoph. 1825. 
A Greca, FLEMING, (not Lam. nor Desh. in Enc. Méth.) Brit. Anim. 
p- 364.—Forpss, Malac. Monens. p. 34 (animal).— Brit. 
Mar. Conch. p. 134.—Brown, Ill. Conch. G. B. p. 61, pl. 
12, f. 10, 11.—Puuiirrt1, Moll. Sicil. vol. i. p. 116, and vol. 
li. p. 90. 
os apertura, (FRY) Fiemine, Brit. Anim. p. 364. 
BA Europea, SowERsBy, Conch. Illust. Fissurella, p. 5, f. 43. 
5 reticulata, RG&cLUz, Revue Zoolog. Cuvierenne, 1843, p. 110.—HanLEy, 
Brit. Mar. Conch. p. xxxii. 
Sipho radiata, (YouNG) Brown, Illust. Conch. G. B. p. 61, pl. 12, f. 20. 


As the specific epithet Graca, by which this shell has 
usually been designated by British writers, more properly 
belongs to an allied Mediterranean species (neglecta) figured 
by Tournefort, we have followed M. Recluz in the adoption 
of the name bestowed by Donovan. The Greca of Lamarck 
(not of Linnzus) is again different, and is a native of the 
West Indian islands. 

The shape is depressed subconical, and the basal outline 
is oblong or elongated elliptical, a little narrower in front, 
but well-rounded at both extremities ; the lateral edges are 
not contracted, but are slightly or moderately convex. 


From a disposition to spread at the margin, the side 


470 FISSURELLID®. 


surfaces are rather flattish or even a little concave; so too 
is the anterior superficies, the hinder one is tolerably arched. 
The shell is strong, opaque, and devoid of lustre. On a 
ground of white, which is rarely pure, often is squalid, and 
not unfrequently is tinged with green or ochre colour, from 
about five to eight rather irregular rays, sometimes broken 
into more or less confluent spots, may be observed: these 
are dark grey, brownish grey, olivaceous or even dirty 
green; the colouring, in truth, is by no means brilliant. 
The sculpture demands particular attention, since, unless 
due regard be paid to its peculiarities, the species will 
inevitably be confused with some of its many allied exotic 
congeners. A reticulation is effected by the decussation ot 
very numerous radiating costelle, and frequent concentric 
elevated lines. The former are rather strongly elevated, 
not much rounded, alternately slightly larger and smaller, 
closely disposed (we have counted fifty upon a specimen 
not an inch long), yet always with a distinct but very 
narrow interstitial space; the latter are much less coarse 
and prominent, are moderately far apart, and become 
somewhat lamellar, or even a little squamular (not nodose), 
at the intersection.* The vertex is before the middle of 
the shell, but is not marginal; in the very young it is fine 
and subspiral (at this stage the foramen precedes it), but 
soon becomes worn off, and the summit is then occupied 
by a rather small simple oblong perforation, of which the 
internal ring or border is tolerably broad, not different in 
colour from the general white hue of the interior, and is 
sometimes rounded, but more often subtruncated, ante- 


riorly. The basal margin is strongly dentated, and the 


* In Patella Greca of Linneus, the ribs and concentric lines are much more 
closely disposed; in Fissurella Greca of Lamarck, the clathration is much 
coarser, and nodulous at the intersection. 


FISSURELLA. A471 


teeth are so arranged that many of them appear bifid. 
Few examples exceed an inch in length. 

Animal bulky, varying in colour from tawny and creamy 
white, through various shades of yellow to a rich orange 
approaching scarlet, in the latter case only in such speci- 
mens as are taken from the surface of scallops incrusted with 
crimson sponge. The head is placed beneath the shorter end 
of the shell; it is tumid with a rather prominent muzzle, 
and bears two stout subulate tentacles, but capable of consi- 
derable elongation ; at their external bases are very short 
pedicles bearing rather small eyes. The mantle is very 
wide-margined, extending beyond the edges of the shell ; 
above the head it is produced so as to form an expanded 
hood or veil; its edges are scalloped, and bear on their 
upper surface, immediately under the margin of the shell, 
a circle of very small and short but stout cirrhi, correspond- 
ing to the ribs. The foot is very large, expanded, ovate, 
and broad-sided. At its junction with the body there is 
a row of short cirrhi, more than thirty in number in a 
specimen of average size, and usually alternately larger and 
smaller; the cirrhus next the head is rather longer than 
the others. Above the line of cirrhi the sides are paler 
coloured than below. The anal tube is of a brownish 
white colour and has simple margins. 

This Mollusk is western and southern in its range, 
extending from the English Channel, round by the Irish 
Sea and west coast of Ireland, to the Hebrides, and 
thence to the Orkneys. We are not aware of its having 
been taken in the German Ocean northwards of the Kentish 
coast. It is found usually adhering to shells, and ranges 
from the laminarian zone to as deep as fifty fathoms. The 
following localities will illustrate its range: Herm (S. H.); 
Margate (S. H.), in fifteen to twenty fathoms; west bay 


472 FISSURELLIDA. 


of Portland (M‘Andrew and E.F.); Exmouth (Clark) ; 
Falmouth (Cocks); bays, near Swansea and Torbay 
(Jeffreys); in twelve fathoms Milford Haven, and in 
twenty-five fathoms Anglesea (M‘Andrew and E. F.); 
around the Isle of Man in from twelve to twenty-five 
fathoms (HE. F.); Clyde (Smith) ; Loch Fyne, Oban, and 
Stornoway (Barlee); cast on the shores of Sanda and 
Stronza, Orkney (Thomas). Among Irish localities may 
be mentioned Birterbuy Bay (Barlee); Clew Bay, in 
from three to ten fathoms (Ball, Thompson, and E. F.) ; 
Bantry (Jeffreys); and in fifty fathoms, but dead, on the 
Nymph Bank (M‘Andrew). 

It does not appear to range northwards in Britain ; 
southwards it extends to the Mediterranean. As a fossil 
it dates with certainty from the epoch of the coralline 
crag. 


SPURIOUS. 
F. nuzecuua, Linnezus. 


Patella nubecula, Linn. Syst. Nat. ed. 12, p. 1262 (from type). — Tur. Couch. 
Diction. p. 142, f. 81 (from type). — Diiiw. Recent Shells, 
vol. ii. p. 1061. 
Fissurella rosea, SOWERBY, Conch. Ill. Fissur. f. 8? — Pumipri, Moll. Sicil. 
vol. ii. p. 91. 
a nubecula, FLEMING, Brit. Animals, p. 365. 
»  nimbosa, Puuipri, Moll. Sicil. vol. i. p. 117. 


A Mediterranean shell ; introduced by Turton as said to have 
been dredged off the Cornish coast. Whether the F. nubecula of 
Macgillivray (Moll. Aberd. p. 345, from which Brit. Marine 
Conch. p. 251) ts identical we cannot say (not having seen his 
specimen), but the fifteen broad ribs ascribed to it, are neither 
present in T'urton’s example nor in those sent us by Dr. Philippi. 


wy 


PUNCTURELLA. 473 


PUNCTURELLA, Lowe. 


Shell conical, with an elevated slightly recurved 
obliquely subspiral entire vertex, turned towards the 
posterior end; aperture expanded, oval; surface with 
radiating ribs; margin entire; a linear perforation in the 
upper part of the shell, between the vertex and frontal 
margin, in the line of an elevated rib. Interior with a 
linear groove corresponding to the perforation and frontal 
rib, vaulted over in its upper part by a shelly plate. 
Muscular impression crescentic, with slightly-incurved 
extremities, interrupted in the region of the head. 

Animal with a short muzzle-shaped head, bearing two 
subulate tentacles, which have the eyes placed on promi- 
nent bulgings, or rudimentary pedicles, at their external 
bases; a range of cirrhi interrupted behind on each side ; 
mantle simple-edged ; anal siphon very prominent, forming 
a truncated membranous canal projecting from the suba- 
pical perforation ; branchial plumes two. 

The curious shell from which this genus is founded, 
rejoices in three if not four appellations, devoted entirely to 
itself: we adopt that which was given it with a full under- 
standing of its claims to generic distinction by a naturalist 
whose every labour among the Mollusca is so excellent, 
that we could wish his published researches were much 
more numerous than they are. The synonyms, Crmorta 
and Sypno, cited in nomenclature catalogues as of prior date, 
were neither of them published with generic diagnoses, and, 
moreover, seem to have been suggested to their authors by 
the fry of the Fissurella Greca. Loven refers the following 
shell to the Rimuta of Defrance (founded for certain fossils, 


WOle Wir 3 P 


474 FISSURELLID&. 


and of which recent species have been found by Mr. 
Cuming), but not correctly, for in the shells of that genus 
there is no internal partition. 


P. Noacuina, Linnzeus. 


Plate LXII. fig. 10, 11, 12, and (Animal) Plate B.B. fig. 4, 5, 6. 


Patella Noachina, Linn. Mantissa, p. 551.—CueEmn. Conch. Cab. vol. xi. p. 186, 
pl. 197, f. 1927, 1928.—Diniw. Recent Shells, vol. ii. 
p. 1055. : 

», fissurella, MULLER, Zool. Danic. pl. 24, f. 5, 6.—O Fapric. Fauna 
Greenland. p. 384.—GMELIN, Syst. Nat. p. 3728.—Donoy. 
in Rees’ Cyclop. Conch. pl. 1, bis (1811). ? 

Fissurella Noachina, SCHUMACHER, Syst. Vers, Testac. (1817) p. 181.—Brit. 
Marine Conch. p. 134, f. 178.—SoweErpy, Conch. Illustr. 
Fissurella, p. 5, f. 15.--Dzsu. Lam. Anim. s. Vert. vol. 
vil. p. 604. 

Puneturella Noachina, Lowe, Zoolog. Journ. vol. iii. p. 78 (Jan. 1827). ALpEr, 
Cat. Moll. Northumb. and Durh. p. 70. 

Cemoria Flemingii, LEAcH (MSS. quoted by Lowe, Zool. Journ. vol. iii.).— 

- Sowrrsy, Conch. Manual, p. 244. 

»  Noachina, Goun, Invert. Massach. p. 156, f. 18.—Dexay, New York 
Fauna, Moll. p. 156, pl. 9, f. 195.—SEartes Woop, Crag 
Mollusca, p. 166, pl. 18, fig. 5 (fossil). 

Rimula Flemingit, Maceit. Moll. Aberdeenshire, p. 178. 

» Noachina, CoutHovuy, Boston Journ. N. H. vol. il. p. 87.—LovEn, 
Index Moll. Scandinav. p. 21. 

Sipho Noachina, Brown, Illust. Conch. G. B. p. 61, pl. 12, f. 14, 15, 16. 


The Patella Noachina of Linnzus, first known to us as 
a fossil, is a conical, subpellucid, and not very strong shell, 
of an uniform white, both within and without, externally 
rather dull, internally lustrous. It is laterally compressed, 
yet a little inclined to spread at the base; the front slope 
is rather more abrupt than the hinder one, but both are 
straightish, the former inclining, however, to the convex, 
the latter to the concave. The vertex is either in the 
middle or slightly precedes it; it is recurved, acute, and 
minutely and laterally subspiral. Just before it is a longi- 


PUNCTURELLA. AT5 


tudinal chink or crevice, which is not of equal breadth 
throughout, but tapers above, chiefly enlarges near its lower 
extremity, and then again slightly contracts; it never 
approaches the base of the shell, being distant from it, in 
the adult, at the least two-thirds of the length of the front 
area. It communicates with a small square-mouthed funnel- 
shaped chamber, whose walls are detached at the broader 
end, but are strengthened at their commencement by a 
transverse lamina of shelly matter. The margin or aperture 
of the shell is more or less oval, rounded at the extremities, 
and tolerably convex at the sides; it is crenately undu- 
lated by the external sculpture. This last consists of 
numerous radiating narrow costelle, that are alternately 
larger and smaller, and are rendered rough, and, in the 
young, and toward the vertex of the adult, subgranular, by 
a fine and crowded concentric decussation. 

One of our largest examples measures four lines in 
breadth, and rather exceeds five in length. 

The animal is white. The head, which is tumid but 
short, bears two rather. obtuse subulate stout tentacula, 
with the eyes, which are very large, on prominent bulg- 
ings, or short peduncles at their external bases. The 
mantle is simple-edged. The foot is oblong and not steep 
or high-sided ; at its junction with the body there are, on 
each side, six or seven short cirrhi, and an odd one, larger 
than the rest, and behind them on the left side. There 
are no cirrhi posteriorly. From the anal cleft projects a 
conspicuous truncated sheath-like membrane, open in front, 
where there are three or more retractile papille. The 
branchie are distinctly visible in the cavity behind the 
head. 

This very curious shell was first observed as a fossil by 
Linneus himself, in the pleistocene beds of Sweden. Not 


476 FISSURELLIDA. 


until of late years has it been taken alive, and British cabi- 
nets were for a long time supplied with specimens from the 
pleistocene beds of the Clyde. Mr. Smith, of Jordan Hill, 
was the first to maintain its existence in the living state in 
the British seas. Except on the Northumberland coast, 
where it has been taken at Cullercoats, by Mr. Alder, and 
in fifty fathoms sixty miles to the east of the north coast 
of Durham, by Mr. King, its localities are all Scottish. It 
ranges in depth from twenty to one hundred fathoms, and 
occurs at intervals throughout the Hebrides, and off the 
coast of Zetland (M‘Andrew, Jeffreys, E. F.). In from 
thirty to eighty fathoms on the west coast of Orkney ; 
alive, on stones, in thirty-five fathoms, Buchanness, and in 
sixty fathoms, Troup Head (Thomas). 

It is a species essentially of northern origin, and has now 
its chief habitats in arctic and boreal seas, extending along 
the coast of Greenland, and down those of Boreal America 
to Cape Cod. It dates its origin from the pleistocene epoch, 
and can only be regarded as a lingerer in our existing 
seas. 


EMARGINULA, Lamarck. 


Shell conical, with an elevated slightly recurved entire 
vertex (obliquely subspiral in young specimens) turned to- 
wards the posterior end; aperture expanded oval; surface 
with radiating and cancellated striz or ribs; emarginated 
in front by a slit which runs for some distance up the shell, 
and is continuous with a closed groove which reaches the 
apex ; interior without a partition ; muscular impression 
crescentic, with deeply incurved extremities, interrupted in 
the region of the head. 

Animal with a short muzzle terminating a tumid head 


EMARGINULA. ATT 


bearing two subulate tentacles with subpedunculated eyes 
at their external bases; a range of cirrhi around the sides 
at the base of the foot ; mantle simple-edged ; anal siphon 
with its angulated membranous sides projecting from the 
edges of the fissure; branchial plumes two. Tongue (ac- 
cording to Lovén) with numerous transverse dental ele- 
ments; its rachis composed of nine teeth, the central one 
laminar and subquadrate, the lateral teeth (wncini) very 
numerous. 

Lovén suggests that an isolated cirrhus which is present 
on the back of the foot in this genus (and which we have 
observed also in Puncturella) may be a rudimentary oper- 
culigerous lobe. 

This is a genus of ancient appearance within our area, 
where species of it were present during the older secondary 
period, if not before. Those now living enjoy a great 


range in depth. 


E. reticutata, Sowerby. 


Clathrated; vertex but little recurved in the adult, always fall- 
ing within the basal circumference ; fissure short and narrow. 


Plate LXIII. fig. 1, as Miilleri. 


ListER, Hist. Conch. pl. 543, f. 28. 

Patella fissura, Linn. Syst. Nat. ed. 12, p. 1261 (only in part and not well).— 
PENN. Brit. Zool. ed. 4, vol. iv. p. 144, pl. 90, f. 152.—Da 
Costa, Brit. Conch. p. 11, pl. 1, f. 4.—Putrenery, Hutchins, 
Hist. Dorset, p. 51.-—Donov. Brit. Shells, vol. i. pl. 3, f. 2.— 
Mont. Test. Brit. vol. ii. p. 490 (adult).—Maron and Rack. 
Trans. Linn. Soc. vol. viii. p. 235 (in part)—Rack. Dorset 
Catalog. p. 59, pl. 23, f. 4.—Turv. Conch. Diction. p. 141.— 
Miter, Zool, Dan. pl. 24, f. 7, 8.— Brookes, Introd. Conch. 
f, 127.—Ditiw. Recent Shells, vol. ii. p. 1054.—Woop, 
Index Testac. pl. 38, f. 86.—Mawe, Linn. Conch. pl. 32, f. 1. 

Emarginula reticulata, J. SowErBY, Min. Conch. pl. 33, lower figs. (fossil). 
» _ fisswra, FLEMING, (not Lam.) p. 365 (in part, not var.).— JOHNSTON, 


478 FISSURELLIDA. 


Berwick Club, vol. ii. p. 33. — Mace. Moll. Aberd. p. 
178.—Brit. Mar. Conch. p. 133 (not var.).— Brown, 
Illust. Conch. G. B. p. 62, pl. 12, f. 17, 19.—Poriez and 
Micu. Gal. Douai, Moll. p. 519, pl. 36, f 15, 16. 
Emarginula levis, REcLuz, Revue Zoolog. Cuvierienne, 1843, p. 232. 
x curvirostris (YOUNG), Maca. (not Desh.) Moll. Aberdeens. p. 331. 


The collection of Linnzus having confirmed the decision 
arrived at by M. Recluz solely from a critical perusal of the 
“« Systema Nature,” that this is not the Patella fissura of 
the author of that work, we are compelled to find another 
name for this well-known shell. The specific epithet Jevis 
must be rejected, since, besides its incorrectness, it was 
applied through an erroneous impression that this was the 
Patella levis of Pennant. 

When adult this shell is conical, strong, and opaque, 
with the vertex simply and slightly recurved, and not even 
hooked: when young the texture is thin and semitrans- 
parent, the shape much more depressed, and the vertex 
acute, much curved, and almost obliquely subspiral; in 
all stages, however, a line let fall from the vertex would 
fall within the margin. The shell, which exhibits a slight 
lateral compression, the side surfaces being but little con- 
vex, 1s both within and without of a more or less clear 
white; the front dorsal outline is only moderately arched. 
The base, which is oval or elliptical, is rounded, and of 
nearly equal breadth at both extremities, and slightly or 
else moderately convex at the sides, but usually bulges out 
a little at the hinder part of the left one. The marginal slit, 
which is long, very narrow, slightly oblique, and as broad 
above as below, reaches to about two-fifths of the direct 
(not the superficial) height, but rather exceeds that propor- 
tion in the young, rather falls below it in the adult. Its 
previous course is indicated externally by a simple sulcus, 


that merely exhibits fine and closely set concentric striz, 


EMARGINULA. 479 


instead of the general sculpture. This last consists of a 
clathration produced by the intersection of rather promi- 
nent narrow ribs, and almost equally strong concentric 
elevated lines; the hollows are profound, and of a squarish 
form. The basal margin exhibits indentations correspond- 
ing to the ribs. Five lines in length, and four in breadth 
and height, may be considered the full dimensions of this 
Emarginula. 

The animal is white, and closely resembles in all its 
features that of the succeeding species, but the foot is 
never so bulky. 

This species is generally distributed around our shores, 
and is especially abundant in the North and in the Irish 
Sea. It inhabits shell banks and clear ground in from 
near low-water-mark to as deep as ninety fathoms, abound- 
ing most in from twelve to twenty fathoms. It is found 
all along the western shores of Europe. 


E, rosra, Bell. 


Ribs subgranose or somewhat geniculated ; vertex greatly 
recurved, on a level with, or extending beyond, the posterior 
margin ; interior occasionally tinged with rose-colour. 


Plate LXIII. fig. 3. 


Lepas, &c. Martini, Conch. Cab. vol. i. p. 145, pl. 12, f. 109, 110 (probably). 
2 Patella fissura (vounG), Monr. Test. Brit. vol. ii. p. 491. 
Emarginula conica, SCHUMACHER, Syst. Vers, Testac. (1817), p. 181 (no de- 
scription; solely from Martini’s figure). 
es rosea, BELL, Zoolog. Journ. vol. i. (1824), p. 52, pl. 4, f. 1; Annals 
Philos. 1825, p. 388.— Han. Brit. Marine Conch. p. 
xxxii.—Brown, II]. Conch. G. B. p. 62, pl. 12, f 21, 22. 
—R&civz, Revue Zool. Cuvierienne, 1843, p. 234. 
53 pileolus, MicuAup, Bulletin Linn. Soc. Bordeaux, vol. iii. (1829), 
p- 171, f. 23, 24, teste Puizipp1, Moll. Sicil. vol. ii. p. 89. 
5 capuliformis, PHiLipPi, Moll. Sicil. vol. i. p. 116, pl. 7, f. 12. 


480 FISSURELLIDA. 


The beautiful rosy hue of the aperture, from which 
this species has derived its name, must, we fear, be con- 
sidered exceptional, rather than otherwise, since, in the 
majority of individuals, the shell is of a squalid white 
both within and without. Its shape is more or less 
conical, but with the front dorsal outline very strongly 
arched, and the vertex greatly recurved, so that a line 
dropped from the most projecting posterior portion of it 
would fall beyond the basal margin. The sides of the 
shell, which is tolerably strong for its size, devoid of 
lustre, and nearly opaque, are somewhat compressed; the 
base is oval or rounded oval, slightly or but moderately 
convex at the sides, arched at both extremities, and a 
little reflected posteriorly. Behind the vertex, which is 
hooked and subspiral, the outline is much inecuryed, and 
the declination is very abrupt. The marginal slit is 
narrow, and of equal breadth throughout ; although nearly 
as high as in the preceding species, it is much shorter in 
proportion to the distance from its termination to the 
extreme point of the vertex. The sculpture, at first sight, 
bears much resemblance (especially in worn specimens) 
to that of reticulata, but in characteristic and uninjured 
examples, the longitudinal ribs are distinctly seen to be 
closer set, larger in proportion to the interstitial spaces, 
and subgranose, or rather subgeniculated, the concentric 
lines to be less prominent and very oblique, and the pro- 
found hollows to be on a smaller scale. The ordinary 
length is not above the fifth of an inch. 

Animal white. The head projects immediately in front 
of the fissure in the shell, and is rather short and small, 
with an oblong muzzle; the tentacula are rather long, but 
stout; at their external bases are distinct but short pedi- 


cles, bearing rather large eyes. The mantle does not 


EMARGINULA. 481 


project beyond the shell; its edges are scalloped, and 
in front it is emarginated on the region of the anal fissure, 
which is bordered on each side by an angulated projecting 
lobe. The foot is large, strong, and very steep-sided ; 
at its Junction with the body is a circle of about twenty 
rather distinct very short papillary cirrhi. 

This species which, though closely approaching some 
varieties of the last, is probably very distinct, is, so far 
as we have seen, on our shores, mainly a southern form. 
It was first taken at Poole by Professor Bell. It occurs 
on the rocks at Herm (S. H.); Exmouth (Clark) ; in seven 
fathoms, Weymouth Bay ; in fifteen fathoms west bay of 
Portland; and in twenty to twenty-five fathoms off 
Plymouth (M‘Andrew and E. F.); Langland Bay near 
Swansea (Jeffreys) ; Fowey, Cornwall (Peach). 

Mr. Dillwyn received a specimen from Montagu under 
the name of fissura (Jeffreys). Mr. Jeffreys and Mr. 
Barlee both mark its occurrence in the Hebrides, but 
though we have frequently met with very hooked varieties 
of the last species, we never saw a specimen there which 
appeared to be a true rosea. 

It ranges to the Mediterranean, and the fossil shells 
designated jissura in the crag seem to us to belong to 
rosed. 


Ei. crassa, J. Sowerby. 


Not clathrated ; vertex subcentral ; slit short. 


Plate LXIII. fig. 2, and (Animal) Plate CC. fig. 2. 


Emarginula crassa, J. SowERBy, Min, Conch. pl. 33 (fossil)—Forsrs, Annals 
Nat. Hist. vol. xiv. p. 410, pl. 10, f. 1.— THompson, 
Annals Nat. Hist. vol. xviii. p. 384.— LovEn, Moll. 
Scandinay. p. 20.—Nysr. Coq. foss. Belg. p. 352, pl. 36, 
f, 3 (fossil). —SraritEes Woop, Crag Molluse. p. 165, pl- 
xvili. f. 2. 


Olen ile 3 Q 


482 FISSURELLID. 


This magnificent species, the largest recent Hmarginula 
at present known to us, has, until very lately, been solely 
observed in a fossil state. 

Itis white both within and without, rather solid and 
strong when adult, almost opaque, and of a more or less 
conical figure. The sides are slightly compressed, the 
front dorsal outline is moderately arcuated ; the hinder 
dorsal outline is concave above, straightish below, and by no 
means abruptly sloping. The base is elliptical, or oboval, 
nearly equally rounded at both extremities, and mode- 
rately convex at the sides; the broader it is, the more 
arcuated are the side-margins, and the less elevated, and 
the less compressed is the shell. The vertex is acute and 
recurved, but not so posterior as in most of this genus; in 
the younger shells it is situated at about two-thirds the 
distance from the anterior extremity, in the adult it is 
very much more central. The slit which is of equal 
breadth throughout, and rather broad in proportion to its 
length, extends but a little space from the margin, being 
in general as three to fourteen ; its proportion to the length 
of the base is very small; its previous course is indicated, 
as usual, by arcuated concentric striea. The sculpture is on 
a small scale for the size of the specimens, and consists of 
an immense number of slightly elevated radiating strie, 
generally grouped by threes and fours, upon the larger ex- 
amples, in the form of depressed costellz, that as well as the 
very narrow interstices are decussated, and rendered slightly 
granose, by very crowded coarse wavy concentric wrinkles. 
The peculiarly close and depressed nature of this decussa- 
tion is remarkable; the hollows between the intersection 
are extremely small and shallow ; indeed, towards the base, 
where the interstices (always small) become more and more 


diminished in size by finer intermediate radiating striae, and 


EMARGINULA. 483 


the closer approximation of the concentric wrinkles, they 
are merely point-like indentations. The basal margin ex- 
hibits crene corresponding to the sculpture of the exterior. 
Our largest example measures fourteen lines in length, and 
at least ten in breadth. 

The animal, of which a drawing has been communicated 
to us by Mr. Alder, is white. The tentacula are thick 
and cylindrical, and the eyes appear to be less, in propor- 
tion, than in our other species. The sides of the foot are 
narrow, and at their junction with the body there are above 
thirty short somewhat unequal cirrhi. The margin of the 
mantle is rather thick. 

This rare shell was known as a fossil in the coralline 
and red crags of England and Belgium, and in the pleis- 
tocene of Norway before it had been discovered alive. In 
our seas it was first announced as British by Mr. M‘Andrew, 
and is one of the most precious and beautiful of recent 
additions to our Fauna. It has been dredged in twenty-five 
fathoms in Loch Fyne (M‘Andrew); in Loch Carron, off 
Skye, and at Oban (Jeffreys). In the last mentioned loca- 
lity it was also taken by Mr. Alder. It has been taken in 
all these localities, and in Loch Long by Mr. Barlee. On 
the Irish coast it has been taken at the entrance of Belfast 
Bay in twenty fathoms by Mr. Hyndman and Mr. Getty, 
and specimens have been sold in Dublin as taken from the 
Irish bank. It has recently been procured somewhere 
between the coasts of Wales and Ireland. 


It inhabits the Norwegian seas. 


In concluding our account of the limpets, we think it advisable to mention, 
that neither the Patella orbiculata of Turton’s (Conchological Dictionary, p. 135), 
nor the P. eatinctorium, and P. tricornis of the same work, belong to the Mol- 
lusca ; the two latter are opercula of Amnelides. 


484 


HALIOTIDA. 


Tue car-shells constitute a very natural passage from the 
Patelliform Mollusks to the Zrochus tribe, combining in 
both animal and shell many of the features of the latter 
family with some of the peculiarities of the Fissurellida. 
Milne Edwards * has described some remarkable arrange- 
ments of the circulatory system common to Haliotis and 
Patella, whilst the dental system of the former genus 
strikingly reminds us of Zvochus, as do the pedunculated 
eyes, lobed head-veil, and cirrhated side-lobes. There are 
two branchial plumes. The shell is greatly expanded and 
furnished with a short and small spire; in most cases 
it is either notched or perforated at intervals, in this re- 
spect approaching Hmarginula and its allies. The typical 
genus Haliotis, though one of great extent in tropical and 
southern regions, where it includes numerous and gigantic 
species often of exquisite beauty, is included in the British 
Fauna rather by courtesy than by strict right, seeing that 


its range does not extend beyond the Channel Islands. 


HALIOTIS. Linnaus. 


Shell ear-shaped, depressed, externally smooth or undu- 
lated or striated, internally nacreous ; spire very short, and 


placed as if laterally ; mouth» very large, broader than 


* Ann. des Sc. Nat., Series 3, vol. viil. p. 37. 


HALIOTIS. 485 


long, entire-edged, a series of perforations forming an are 
parallel with and near to its left margin, and continuous 
with the spiral crest of the convolutions. 

Animal shaped like the shell, its head terminating in a 
short muzzle and bearing two subulate tentacles and two 
stout eye-peduncles at their external bases; a fimbriated 
lobe between the tentacula apparently continuous with the 
fimbriated and cirrhated lateral lobes of the body; lateral 
cirrhi numerous. Foot very large, oblong, rounded at the 
extremities, bearing on its upper extremity a rudimentary 
operculigerous lobe, but no operculum. Branchial plumes 
two. Dental system of a median tooth flanked by two 
laterals, four primary accessorials, and numerous second- 
aries. 

This genus is littoral in its habits. It is characteristic 
of the present epoch, and as a fossil is only known in the 
later tertiaries. It occurs in the miocene beds of Malta, 


but no species is found fossil in British formations. 


H. rusercunata, Linneus. 


Plate LXIV. and (Animal) Plate C.C. fig. 3. 


Lisrer, Anim. Angl. pl. 3, f. 16.—RzcEnr. pl. 10, f. 42. 

Haliotis tuberculata, L1NN. Syst. Nat. ed. 12, p. 1256.—PEwnn. Brit. Zool. ed. 4, 
vol. iv. p. 141, pl. 88.—PunTENeEy, Hutchins, Hist. Dorset, 
p- 50. — Donov. Brit. Shells, vol. i. pl. 5. — Monr. Test. 
Brit. p. 474. — Maron and Rack. Trans. Linn. Soe. vol. 
viii. p. 227. Racket, Dorset Catalog. p. 57, pl. 22, 
f. 1, 2.— Fiemine, Brit. Anim. p. 362.— Brit. Marine 
Conch. p. 155.—Browy, Illust. Conch. G. B. p. 23, pl. 12, 
f, 2, 18.—Donoy. in Rees, Cyclop. Conch. pl. 6, (1808). 
—Ditiw. Recent Shells, vol. ii. p. 1009.—Woop, Index 
Testac. pl. 36, f. 4. — Lam. Anim. s. Vert. (ed. Desh.) 
yol. ix. p. 26. — Dusn. Encyclop. Méthod. Vers, vol. ii. 
pt. 2, p. 179.—D’Orsieny, Moll. Canar. p. 95, pl. 7, f. 1, 
animal (probably).—Purtippi, Moll. Sicil. vol. i. p. 165 ; 
vol. ii. p. 142. — Hannu. Young Conch. p. 59.—REEvE, 
Conch. Iconica, vol. iii. Haliot. pl. 11, f. 34. 


486 HALIOTIDA. 


9 


Auris marina §c. Marrini, Conch. Cab, vol. i. pp. 187, 188, pl. 16, f. 148, 
149. 
Hlaliotis vulgaris, DA Costa, Brit. Conch. p. 15, pl. 2, f. 1, 2. 


The colouring of this shell, which is not much swollen, 
and whose shape is oval, or oboval, is peculiarly variable, 
scarcely any two specimens being precisely alike. The com- 
ponent colours of its painting are green and red, with an occa- 
sional mottling of white. The green is generally bluish or 
olivaceous, the red ranges from purplish to brownish rufous, 
but is more frequently of a brick colour: these hues either 
shade into each other, or angulated patches or cloudy 
markings of the darker tint adorn the paler one. The ex- 
terior in some individuals is flatly costellated, the intervals 
of the ribs being almost linear ; plano-convex unequal cos- 
tellee, whose interstices are about as broad as the finer of 
them, cover the surface of other, and chiefly aged, examples; 
the sculpture in some, again, is so close and fine that the 
exterior is rather striato-sulcated than ribbed. Neither the 
raised nor the level portions of the surface can be termed 
cancellated, but most minute and densely disposed longi- 
tudinal striule are occasionally perceptible. There is 
usually a slight retusion of surface midway between the 
foraminal tubercles and the spire; the former are mo- 
derately prominent, and tolerably large; from six to 
eight are open; the perforations are in general oval or 
rounded oval. Beyond these is a rather broad and 
strongly indicated shallow channel, or excavated area, 
whose limit is well defined by a coarse rib, succeeded by 
other similar but less strong ones. Some wavy longi- 
tudinal folds are occasionally present, but the surface is 
more frequently only undulated at the stages of increase. 
The spire is remarkably small, the body or final volu- 


tion being most abruptly enlarged; it is obliquely and 


HALIOTIS. 487 


moderately elevated ; the apex is generally more or less 
prominent. The internal nacre is soft and silvery; it 
is iridescent, but does not sparkle with those rich and 
brilliant hues that adorn some of the exotic Ear-shells; 
neither is there any peculiar stain beneath the spire, only 
a single coil of which is visible from within. The outer 
lip is more or less arched; the inner lip, or pillar, is 
moderately broad, rather flattened, and not much attenu- 
ated at its termination. Our largest specimen measures 
three inches and three quarters in breadth, and two inches 
and a half across from side to side. 

The animal is variously tinted with tints of brown, 
green, white, and salmon colour. The head and tentacula 
are brown, the eye-peduncles white, the eyes blue. The 
lateral cirrhi, which thickly fringe the side lobes, are 
greenish and brownish; the side-lobes themselves striped 
alternately with brown and greenish white. The sides 
of the foot are dark greenish brown; its disk, which is 
rounded at each extremity, of a salmon colour. 

This handsome shell is an inhabitant of the very verge 
of the littoral zone, living near and under rocks and 
stones. It takes its place in the British Fauna solely 
on account of its presence in the Channel Islands, where 
it is abundant, and known by the name of Ormer. It is 
cooked for food, after being well beaten to render it 
tender.. A more important use of it is in the making 
of the mother-of-pearl ornaments which constitute so 
much of the beauty of works in papier maché. Great 
quantities of Haliotis are brought to Birmingham for this 
purpose. 

This Haliotis has at various times been published as 
an inhabitant of different parts of England and Ireland. 


There can be no question that the instances alluded to 


488 HALIOTIDA. 


have been founded on some mistake, or on the circum- 
stances of some stray specimen having found its way 
from its habitat on a chimney-piece to the cabinet of some 
over-zealous, but not discriminating, British collector. It 


ranges south of Britain as far as the Canaries. 


489 


TROCHIDA. 


Tue Top-shells constitute a numerous family, remarkable 
for exquisite beauty of form and colour, both of shell and 
animal. Some of our most elegant British univalves belong 
to this tribe, and many of the most ornamental exotic 
shells. Their animals have all pedunculated eyes ; heads 
terminating in a muzzle, and often ornamented with head- 
lobes ; side-lobes greatly developed, and ornamented with 
lappets and lateral cirrhi; a tail bearing a spiral oper- 
culum, sometimes horny, sometimes shelly ; a single bran- 
chial plume, and a dental system remarkable for the 
number of accessory lateral denticles. The shells vary 
much in form, ornament, and structure, some being discoid, 
whilst others have greatly produced spires; though, in all, 
the spire forms a very considerable portion of the entire 
shell. Their orifices are entire, but vary much in out- 
line. 

In formations even of paleozoic age we find the shells of 
Mollusca of this family often resembling closely, in general 
outline, existing forms. The so-called Huomphali, Cirrhi, 
and the greater number of Pleurotomaria, appear to have 
been allies of Delphinula, Turbo, and Trochus. 


TROCHUS. 


Shell very variable in form, sculpture and_ strength, 
conical, subglobose or subdepressed, texture partly nacreous, 


VOL, II. op 


490 TROCHIDZ. 


spire of several whorls, aperture entire, usually angulated, 
sometimes nearly round; base perforate or imperforate. 

Animal with a large head terminating in a short pro- 
boscis, and bearing two subulate tentacles, sometimes 
smooth, sometimes ciliated, and two strong separate eye- 
peduncles at their outer bases ; between the tentacles are 
two more or less developed head-lobes, which, however, in 
some species are nearly obsolete; next the eye-peduncle, 
on each side, is a large lappet, continuous with greatly 
developed side-lobes, bearing usually three, sometimes four 
or five subulate cirrhi; foot more or less lanceolate or 
oblong, an operculigerous lobe on its upper surface pos- 
teriorly, bearing a many-spired, horny operculum, Gill 
very long, linear. Tongue rather long; each series of 
denticles composed of a central element flanked by five 
hooked lateral and numerous narrow accessorial teeth. 

This extensive genus includes a great assemblage of 
beautiful Mollusks, in which colour, both of soft and hard 
parts, becomes an important character. Our British species 
may be divided under three well-marked, subgeneric 
sections :— 

1. Trocnus. Animal with the inter-tentacular lobes 
very slightly developed. Three lateral cirrhi on each side. 
Shell more or less pyramidal, imperforate ; to this group 
belong ziziphinus, conulus, alabastrum, granulatus, striatus, 
millegranus, exiguus, and Montacuti. 

2. Gissuta. Animal with largely developed inter-ten- 
tacular lobes. Three lateral cirrhi on each side. Shell 
tumidly conical, usually perforate—as 7. Magus, tumidus, 
cinerarius, wmbilicatus, and, though abnormally, Jineatus. 

3. Marcarira. Cirrhi five on each side. Shell tumid, 
thin, usually perforate. 7. Helicinus, undulatus, and 
pusillus. 


— 


TROCHUS. 49] 


Tl. zizypuinus. Linneus. 


Conical, imperforated, either devoid of colour, or painted with 
longitudinal flames, and spotted upon the more or less prom- 
inent marginal belt ; the spiral costellee (when present), and 
their interstices, alike simple in the adult, except at the apex, 
which is not peculiarly stained with rose-colour. 


Plate LX VII. figs. 1 to 6. 


Lister, Anim. Angl. pl. 3, f. 14; Hist. Conch. pl. 616, f. 1. 
Trochus ziziphinus, LINN. Syst. Nat. ed. 12, p. 123].—PENN. Brit. Zool. ed. 4, 
vol. iy. p. 126, pl. 80, f. 103.—- PutrENry, Hutchins, 
Hist. Dorset, p. 44. — Donoy. Brit. Shells, vol. ii. pl. 52. 
-—Mont. Test. Brit. p. 274.— Maron and Rack. Trans. 
Linn. Soe. vol. viii. p. 155.—Rack. Dorset Catalog. p. 48, 
pl. 16, f. 3, 4. — Fiemine, Brit. Anim. p. 323. — Turvt. 
Conch. Diction. p. 189.—ForBes, Malacol. Monens. p. 22 
(animal). — Jounsr. Berwick Club, vol. i. p. 263 (with 
animal), — Brit. Marine Conch. p. 163.— Dimiw. Recent 
Shells, vol. ii. p. 799 (not var.) —Woop, Index Testac. pl. 
29, f. 94. 
»  conulus, PENNANT, Brit. Zool. ed. 4, vol. iy. pl. 80, f. 104 (probably). 
»  2yzxiphinus, BoRN, Testacea Mus. Ces. Vind. p. 337.—BuLainy. Faune 
Frangaise, Moll. p. 258, pl. 10, f. 1. 
»  2xtziphinus, DA Costa, Brit. Conch. p. 37, pl. 3, f. 2. — Brown, Illust. 
Conch. G. B. p, 18, pl. 11, f. 16, 17, 18, 19, 21, 22, 24, 
29.—Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 142. 
»  zezyphinus, CHEMN. Conch. Cab. yol. y. p. 66, pl. 166, f. 1594. 
discrepans, BRowN, Mem. Werner. Soc. vol. ii. pt. ii. p. 519, pl. 24, 
f. 4; Ill. Conch. G. B. p. 19, pl. 11, f. 20, 23. 
conuloides, LAM. Anim. s. Vert. (ed. Desh.) vol. ix. p. 142. — Macein. 
Moll. Aberd. p. 132.—Brarnv. Faune Frang. Moll. p. 259, 
pl. 10, f. 4.——Dzsu. Ency. Méth. Vers, vol. iii. p. 1076. 

»5  Lyonsii, Leach MSS. (cited by Fleming). 

albidus, Woop, Index Test. Suppl. pl. 5, Troch. f. 14. 

Sisyphinus, Maceiu. Moll. Aberd. p. 131. 

Sedgwickii (fossil), Sow.—Nysr. Coq. fos. de Belge, p. 380, pl. 35, f. 20. 


From the derivation of the name of this species having 
been made the subject of much discussion, has arisen the 
great diversity of spelling discernible in our synonymy ; 
Professor Macgillivray deduces it from the rolling stone of 
the legendary Sisyphus, and Chemnitz from the plant 


492 TROCHIDA. 


sezypha. The ‘“ziziphino colore depictus” (painted like 
the fruit of the jujube) of Gualtier’s description, was pro- 
bably the immediate source of the specific appellation. This 
shell is subject to a peculiarly wide range of variation in 
form, sculpture, and colouring, yet always so far preserves 
the essential elements of its specific character as to render 
a well-defined division of it into two or more species 
almost an impossibility. Otherwise the small deep water 
variety from our Northern and Irish coasts, is so aberrant, 
as almost to warrant its separation from the normal form. 
The shell is tolerably strong, opaque or nearly so, and 
more or less shining; the shape is always purely conical, 
but varies considerably in the relative proportions of height 
of spire and breadth of base; the lateral outlines are 
slightly concave. The painting consists of several wavy 
longitudinal blotches or flames of pinkish red, dark liver- 
colour, or ruddy flesh colour, on a ground of citron flesh- 
colour, or more rarely warm reddish brown, that frequently 
changes to a livid or bluish hue toward the summit of the 
spire. The ground tint is sometimes of a bluish-slate, and 
the entire shell at times is quite devoid of colour; often- 
times, too, the reddish stains are confined to the base of 
each volution, where they form a kind of subarticulated 
fillet (in one of our scarcer varieties this is of a vivid 
purple) ; rarely if ever do they extend further than the 
margin of the base. They are chiefly conspicuous upon 
the bluntly angulated basal circumference. The whorls 
are eight to ten in number, of not very rapid increase, 
much shelving, and rather flattened, or even subretuse; in 
the smooth variety they are more rounded; in the larger 
individuals of the common littoral form, they are occa- 
sionally a little retuse on the body and penult volutions, 


‘The apex is very small and acute, and near it, the narrow 


TROCHUS. 493 


raised spiral fillets, that typically encircle the shell, are 
granular; elsewhere they are simple and round-topped 
(occasionally, however, as in the solid dark produced 
variety we have figured, the subsutural one exhibits, at 
intervals, an obscurely subgranose appearance) ; these cos- 
tellar strize are sometimes coarse, few, and rather distant, 
sometimes numerous, very fine, and not much elevated. 
The inferior one of each whorl which immediately pre- 
cedes the well-defined suture, is always conspicuous for 
size or prominence, and is preserved even in the broad- 
based smooth variety, where the others are wholly or 
partially absent. These spiral lines become flatter upon 
the base of the shell, where they either become indis- 
tinct or transmuted into sulci. The fine and close-set 
wrinkles of increase are at times perceptible upon the 
more rugged individuals, and diverge, as it were, from 
the axis of the shell. The base is imperforated, and, 
except in the smoother specimens, but little convex ; the 
shelve is generally moderate. The mouth is obliquely 
rhombic, and considerably broader than it is long; in 
general it occupies about two-fifths of the entire length 
of the shell, and about one half the basal diameter; no 
sculpture distinguishes it, beyond the traces of the external 
fillets. ‘The outer lip is very acute; the pillar is oblique, 
more or less curved, broad, rounded yet appressed, and 
with its nacre often interrupted or notched at the base 
by the jutting into it of the white callus, which bounds 
it externally. Our finer specimens measure an inch and 
three-eighths both in length and breadth; but these di- 
mensions, although greatly beyond the average, are by no 
means the extreme limit of the size attained. 

The animal is always brightly coloured with reddish 
brown, whatever may be the hue of the shell. Its head 


494 TROCHIDE. 


is rather long, of a dark mottled madder-brown hue, paler 
at the crenated extremity of the muzzle. The tentacula 
are long, smooth, subulate, white or pinkish, and marked 
down their centres by an orange-brown line. At the 
inner sides of each tentacle is a very small almost rudi- 
mentary capital lobe, and on the outer side a stout white 
eye-peduncle bearing a greenish-blue eye at its extremity 
with a black central point. On each side of the neck 
is a large white plain-edged lappet. The side-lobes are 
pale with brownish dots and markings, crenated at their 
edges, and bear three subulate white or pale brownish 
cirrhi on each, with minute rudimentary lobes at their 
bases, recalling the appearance of the tentacular and 
capital lobes. The sides of the foot are closely-painted 
with rich reddish brown colour. The foot itself is ob- 
long, truncated and obtusely angled in front, obtusely 
pointed behind, and minutely crenated at its edges, which 
are pale, whilst the central disk is of a bright salmon 
colour. The opercular lobe is short. The branchial 
plume is long and linear lanceolate. The margin of the 
mantle projects slightly beyond the shell, and is plain. 
The jaws are small, bent, and corneous. The tongue has 
its central denticle escutcheon-shaped, with a broad in- 
curved apex; the laterals have slightly and the acces- 
sorials greatly curved and narrow points. 

This handsome but common shell is found on all our 
shores, and enjoys a range of from low-water-mark to fifty 
fathoms, at which depth it lives on the Ling banks off 
the Zetland shores. Its favourite habitat is in the 
laminarian zone. The white variety (Lyonsii) is, per- 
haps, most abundant in the Irish Sea. It is very plenti- 
ful around Anglesea, in which district the smooth variety 
with tumid whorls has been plentifully taken (M‘Andrew). 


=~ 


TROCHUS. 495 


Abroad it ranges from Norway to the Mediterranean. As 
a fossil it first appeared in our area during the coralline 
erag epoch. 


T. conutus, Linneus. 


Resembling zizyphinus, but combining smoothness and flat- 


ness of volutions, with a purely conical figure, and a rectilinear 
lateral outline. 


Plate LX XIII. figs. 1, 2. 


Bonannl, Recr. pt. 3, pl. 93. 
Trochus conulus, LINN. Syst. Nat. ed. 12, p. 1230.—Brit. Marine Conch. p. 255. 
—Dittw. Recent Shells, vol. ii. p. 988. — Woop, Index 
Testac. pl. 29, f. 93.— Lam. Anim. s. Vert. (ed. Desh.) 
vol. ix. p. 142.— Payraup. Cat. Moll. Corse, p. 125.— 
Puitiepr, Moll. Sicil. vol. i. p. 175, and vol. ii. p. 149, 
var. a. 


a » &c. CHEMN. Conch, Cab. vol. y. pl. 166, f. 1588. 


The synonymy of this elegant Trochus, might have been 
much increased, had we possessed more leisure to investigate 
its exotic varieties. It was only, however, just previous to 
transferring this page from our own hands, that we were 
induced by a letter from our friend Mr. Bean, to include 
the species among our native shells, since neither Pennant’s 
nor Turton’s conulus present the characteristic features of 
the species. The individual delineated in our engraving, 
was, we are assured by that gentleman, taken alive by his 
son, ona voyage from Newcastle to London. ‘The man 
was heaving the lead, somewhere on this (the northern) 
side of the Lincolnshire coast, when this shell adhered to 
it. I had the pleasure of extracting the animal.” 

The specimen alluded to, which is not a typical or pecu- 
liarly characteristic conulus, is conical, moderately broad, 
and with its lateral outlines nearly straight or barely sub- 
retuse. It is tolerably strong, not transparent, and of a 


496 TROCHID®. 


shining livid, or olivaceous white (assuming a rather more 
bluish cast toward the apex), adorned longitudinally with 
distant angular spots and intermediate flexuous lines of 
fawn-colour, the latter of which are somewhat interrupted, 
and evince a disposition towards a spiral arrangement like- 
wise. These markings are irregularly continued upon the 
convex and extremely prominent basal belt, which is rather 
broader than is usual in this species; the inferior surface of 
the shell displays four or five distant articulated bands of 
fawn-colour and livid white, upon a ground of paler fawn. 
Excepting two or three grooves around the imperforated 
axis, a few indistinct spiral striz upon the base, and 
about two profound striz upon the second volution, the 
entire shell is smooth. The eight nearly flat and greatly 
shelving whorls, which increase rather slowly in length, are 
somewhat narrow, the height not being one half the width 
of even the superior suture, and terminate in a rather acute 
apex, that is not distinctly granulated, but when highly 
magnified appears punctulate (possibly from abrasion of 
the surface). The base is abruptly compressed, nearly 
flat, and angulated at the circumference. The aperture is 
rhomboidal, much broader than long, occupies about two- 
sevenths of the entire length of the shell, and about half 
the basal diameter. The outer lip, which is simple and 
acute, recedes moderately at the base. The pillar-lip is 
rather short, oblique, slightly curved, and a little tortuous. 

The breadth at the base, which is scarcely exceeded by 
the length of the axis, is Just one-third of an inch. 

Independently of the difference of colouring, an essential 
character in the Zrochi, the smooth variety of zizyphinus 
does not present a simply conical figure, but has its whorls 
more convex, and its lateral outline more areuated. 

This species is a southern form, common in the Medi- 


~ © “pepe owe te «=f 


TROCHUS. 497 


terranean. Its presence in our seas is probably not due to 
an occurrence in the bounds of its present limits, but rather 
may have relation to its ancient existence in the region of 
the crag. It is recorded by Mr. Searles Wood as a fossil 
of the coralline crag at Ramsholt. 

e 


T. auabastrum, Beck. 


Uniform white, or tinged with golden yellow upon the carinz 
only ; whorls of the spire with three strong spiral keels, the 
body volution with four ; axis imperforated. 


Plate LX VI. fig. 7, 8, as T. formosus. 


Trochus quadricinctus (Fossit undescribed) Annals Nat. Hist. 1842. 
,»» occidentalis, MigHELs and ApAms, Boston Jour. Nat. Hist. (Noy. 1841) 
vol. iy. p. 47, pl. 4, £. 16 probably. 
Margarita alabastrum, Buck in Loyén’s Index Moll. Scand. (1846) p. 20 (from 
type). 
Trochus formosus, ForBes, Annals Nat. Hist. vol. xix. (Jan. 1847) p. 96, pl. 9, 
f. 1.—S. Woop, Crag Moll. p. 125, pl. 13, f. 2 (fossil). 


This extremely rare shell is wrought with a sculpture so 
peculiar, as to enable us to distinguish even a fragment of 
it from any of its British congeners. This consists of a 
few very prominent, strong, but rather narrow, rounded, 
but sharply defined, subequidistant carinz or spiral belts, 
of which the top one is generally broken into tubercles ; 
indeed, upon the upper volutions, two if not the whole 
three—for such is the usual number, excepting upon the 
body, which is generally adorned with four—are similarly 
affected ; the interstices are smooth, and a little concave. 
The general shape of the shell, which does not appear to 
be particularly solid, nor yet translucent, and seems but 
slightly polished (the examples taken are chiefly dead 
specimens, so that we presume not to speak decidedly on 


these points), is simply conical, with the lateral outlines 
VOL. Il. 38 


498 TROCHIDA. 


straight or subretuse; it is either devoid of all colour, or 
more rarely has the belts of a pale golden yellow. The 
elongation of the whorls, which are about six in number, 
is slow; they are rather narrow, moderately ventricose, 
and appear the more distinctly separated from the carine 
not touching the suture either above or below: the apex 
is small, yet can scarcely be termed acute. The basal cir- 
cumference is angulated; the angle for the most part is 
a right one, the base itself is flattish or hardly at all 
rounded, and is merely encircled with two broad grooves 
near the margin, and about four round the imperforated 
axis, the broad strip between these two sets being devoid 
of all sculpture whatsoever. The interstitial spaces be- 
tween the sulci assume the appearance of depressed belts, 
but are not distinctly raised above the general level of the 
superficies. The mouth is nacreous, subquadrangular, 
much broader than it is long, and occupies about a third of 
the entire length of the shell, and about one half of the 
basal diameter: it merely exhibits the vestiges of the 
external carine, not being distinguished by any peculiar 
sculpture of its own. The outer lip is acute; the pillar 
white, narrow, straightish, and not much rounded. Few of 
our British specimens attain to the length of half an inch, 
The animal, which we were so fortunate as to examine 
alive, in one of the specimens dredged off Fair Island, is 
entirely pure white. The head terminates in a rather 
narrow proboscis and bears two long subulate tentacula 
which are minutely ciliated; the eyes are black and 
placed on rather large peduncles; the capital lobes are 
minute and imperfectly developed. ‘The neck-lappets 
are of moderate size and plain-edged; the lateral cirrhi 
are three on each side and rather short and slender as 
compared with the tentacles; they are carried closely 


TROCHUS. 499 


appressed to the shell. The operculum is very pale 
horn-colour. The foot is very broad oblongo-triangular, 
truncated in front with produced and mucronated angles. 
This beautiful species was first taken in the British sea, 
in 1846, in fifty fathoms, among stones on the Ling banks 
off Zetland, and in from forty-five to sixty fathoms off Fair 
Island (M‘Andrew and E. F.). It has since been taken 
by Mr. Jeffreys at thirty miles east of Lerwick. Mr. 
Barlee has taken it in the same region, and Lieut. Thomas 
has dredged it on a stony bottom in sixty fathoms off 
Troup Head, Aberdeenshire, and in forty to eighty fathoms 
on both sides of the Orkneys. During the same year it was 
briefly characterized by Loven, under Beck’s MS. name 
of Margarita alabastrum, and recorded as ranging from 
Bergen to Finmark, on the Scandinavian shores. Should 
it prove the 7. occidentalis of North America, as judging 
from the description we think likely enough, that name 
must be substituted for Beck’s. It appears to be an Arctic 
form. It is found fossil in both coralline and red crags 


(Searles Wood). 


T. eranutatus, Born. 


Whorls with numerous fine granulated or corded spiral cos- 
telle ; base rounded, imperforated. 


Plate LXVII. fig. 7, and pl. LX VIII. fig. 2; Animal, pl. DD. f. 4. 


Trochus papillosus, DA Costa, Brit. Conch. p. 38, pl. 3, f. 3 (probably).— 
Donov. Brit. Shells, vol. iv. pl. 127. — Mar. and Rack. 
Trans. Linn. Soe. vol. viii. p., 155.—Rack. Dorset Catalog. 
p- 48, pl. 16, f. 6. —Turr. Conch. Dict. p. 190, f. 62. — 
Femina, Brit. Anim. p. 323.— Forses, Malac. Monens. 
p- 22, animal.—Brown, Illust. Conch. G. B. p. 19, pl. 11, 
f. 13, 14.—Dimtw. Recent Shells, vol. ii. p. 800.—Woop, 
Index Test. pl. 29, f. 95. 
»  granulatus, Born, Test. Mus. Ces. Vind. p. 337, pl. 12, f. 9, 10.—Brit. 
Marine Corch. p. 162.—Lam. Anim. s. Vert. (ed. Desh.) 


500 TROCHIDA. 


vol. ix. p. 145. — Buarnyv. Faune Frang. Moll. p. 260, 
pl. 10, f. 5. — Puriipe1, Moll. Sicil. vol. i. p. 174, pl. 10, 
f, 22, 22,a; vol. ii. p. 149. 
Trochus fragilis, PuLrENEY, Hutchins, Hist. Dorset, p. 44. 
» tenuis, Monv. Test. Brit. p.275, pl. 10, f. 3. 


Although known traditionally as the papillosus of Da 
Costa, the description by that author is not merely in- 
definite, but essentially adverse, and his delineation by no 
means characteristic. Hence we have preferred the name 
applied to the species by Born, almost immediately after- 
wards. 

The obliquely conoid form of this elegant T’rochus, is 
modified by the dilatation and tumidity of its base. Of the 
eight or nine volutions that compose the shell, the upper 
ones are nearly flat, the penult and ante-penult are slightly 
or moderately convex, and the last, or body-whorl, is 
rounded: the apex is acute, and not differently coloured 
from the rest of the surface. The general hue of the shell, 
which is thin and glossy, and not quite opaque, is a flesh- 
colour, that varies in its intensity and tint, being often 
tinged with brown or yellow ; a few scattered longitudinal 
spots, of a rufous or darker shade of the same colour, appear 
upon the whorls, and a few rows of similarly-painted oblong 
dots are sparingly and subarticulately disposed upon the 
spiral belts of the base, and are often apparent (though 
irregularly and indistinctly) upon those of the spire like- 
wise. There is an Albino variety, but it is rare. The 
sculpture consists of numerous narrow granufated spiral 
belts, that gradually change into’ depressed and simple 
ones upon the base. There appears to be a considerable 
latitude as to the number of these belts, their degree and 
style of granulation, &e. There are generally from six to 
eight upon the penult and ante-penult whorls, and the 


one that precedes the obscurely indicated suture is rather 


TROCHUS. 5OL 


broader than the rest, and occasionally is spirally sub- 
divided. Here and there a scarcely-raised very fine inter- 
mediate stria shows itself in the interstices, which are 
always rather broader, or at least as broad, as the belts. 
The granules upon the smaller whorls are more rounded 
than those upon the larger volutions, the belts of which 
latter have frequently somewhat the look of twisted ropes. 
The apical whorls are cancellated. The usual number of 
belts wpon the upper part of the body is eight or nine, 
besides the obtuse carina ; the entire surface of the shell is 
more or less distinctly marked with delicate longitudinal 
wrinkles. The base is tumid, and imperforated. The 
mouth is large, broader than it is long, and not dis- 
tinguished by any sculpture whatsoever ; the hinder angle 
of it is an obtuse one; the outer lip is very acute; the 
pillar is broad, strong, arcuated, and white. In a Medi- 
terranean example, however, it is edged behind with rufous 
and tinged with pink. 

The animal is much larger in proportion to the shell 
than that of any other native Trochus. It is of a general 
whitish hue, with brown markings. The head terminates 
in a strong and thick muzzle, much speckled with brown. 
On each side is a subulate smooth tentacle, marked with a 
brown line down its centre. The eye-peduncles are stout 
and white, and the eyes blue. The head-lobes are nearly 
obsolete. The neck-lappets are very large, white, and 
even, or only obsoletely crenated at their edges. The 
lateral lobes are white, rugosely crenate, and bear three 
white filaments at each side. The sides of the foot are 
very broad, and thickly speckled with brown. The very 
large foot is lanceolate truncate in front, with mucronated 
angles, and terminating in a point behind. 


This handsome shell is very local, and appears to be 


502 TROCHIDA. 


confined to our southern shores and the Irish sea. Herm, 
in the Channel Islands; Weymouth and Brixham (S. H.) ; 
in fifteen fathoms, west bay of Portland (M‘Andrew and 
E. F.) ; Exmouth (Clark), Plymouth, Falmouth, White- 
sand Bay (Jeffreys), Fowey (Peach) ; north-west coast of 
Isle of Man in twenty-five fathoms, on a scallop beach, 
not rare (E. F.); Dublin coast (Warren), Wicklow 
(Farren), Youghall (Ball), coast of Cork (Humphreys). 

It does not occur to the north of Britain, but south- 
wards ranges to the Mediterranean. Its history as a fossil 
is doubtful. 


T. mittecranus, Philippi. 


Cenical, either whitish, or only articulated with pink on the 
raised sculpture; whorls with numerous cordlike raised strie, 
and a strong inferior marginal belt: apex not coloured ; base 
flattened, imperforated. 

Plate LX VI. fig. 9, 10. 


Trochus Clelandi, GRAY, in Woo0d’s Index Testac. Suppl. pl. 5, Troch. f. 15 (1828). 
»  millegranus, PuwiPr!, Moll. Sicil. vol. i. p. 183, pl. 10, f. 25 ; vol. ii. 
p- 154 (fossil). — THompson, Ann. Nat. Hist. vol. v. 
p. 245.— Han ey, Brit. Marine Conch. p. xxxix. f. 36.— 
Loven, Index Moll. Scandinay. p. 20. 
», Martini, Smrru, Mem. Werner. Soc, vol. viii. p. 99, pl. 1, f. 26.— 
Macein. Moll. Aberd. pp. 132, 349.—Brit. Marine Conch. 
p. 164.—Brown, Ill. Conch. G. B. p. 129. pl. 57, f. 11. 
This pretty Trochus has a simple conical figure, but 
varies in the relative proportions of height and base ; its 
lateral outline is rectilinear, its apex acute, and its base 
flattened and imperforate. It is opaque, or nearly so, 
tolerably strong, more or less dull-surfaced, and of a 
white or yellowish-white hue, that is either uniform or else 
distantly articulated with madder-lake upon its spiral 
sculpture. The elongation of the whorls, which are 


seven or eight in number, is gradual; they are flat or 


ee 


TROCHUS. 503 


nearly so, rather abruptly shelving, well defined at the 
suture, and moderately broad, that is to say their length 
is equal to about one-third to two-fifths of their breadth. 
They are spirally girt with a rather broad and prominent 
basal belt, and with about five or six obliquely subgenicu- 
lately granular raised strize, whose interstices—which, in 
the final volutions are much broader than the strizee—- 
are crowdedly traversed by very oblique raised wrinkles, 
that, in certain specimens, are so immediately connected 
with the granules, as to form continuous series of produced 
tear-drops. The prominent belts, likewise, are not simple, 
but granular and spirally striated: the elevated lines upon 
the base are decidedly broader, rather more distant, and 
as well as their interstices, faintly exhibit the superior 
sculpture. The aperture is subquadrate, but very much 
broader than long, the width being fully equal to half the 
basal diameter, whilst the height does not occupy one- 
third of the total length of the shell. It is not adorned 
with any other sculpture than the indicatiens of that of 
the exterior upon its silvery nacre ; the outer lip is acute, 
and subrectangular below; the pillar is white, very short, 
nearly rectilinear, and slightly oblique. One of our larger 
specimens is nearly seven lines in length, with a base of 
fully half an inch in diameter. The coloured individuals 
have generally their sculpture more granular and better 
defined ; in certain shells, too, there are similar, but much 
finer, spiral stricee between the five principal series. 

Although but recently described as a living shell, some 
Irish examples were in the cabinet of Donovan; and the 
individuals engraved by Wood — whose name, though 
prior, we cannot prefer, owing to the imperfect definition 
of the species by his reduced figure—came from the same 
locality. 


504 TROCHIDA. 


The animal, which we have examined on the Manx 
coast, and of which Mr. Alder has kindly communicated a 
drawing, is of a whitish hue mottled with brown. The 
head is deeply tinged with brown; the head-lobes are 
rudimentary. The tentacles are smooth and subulate, 
white, with a brown line: the eye-peduncles are white, the 
eyes black. The neck-lappets are pale and even-edged. 
There are three brownish-white cirrhi on each side springing 
from the pale side-lobes. The sides of the foot are deeply 
tinged with brown. The foot is lanceolate, pointed 
behind, but with obtuse angles in front. 

This species is much more generally diffused around our 
shores than was once supposed, and though on the whole 
a scarce shell, has been taken in all our provinces. It 
appears to be most frequent in the Hebrides. A few 
localities will serve to illustrate its range in depth. In 
fifteen to twenty fathoms, West Bay of Portland, Welsh 
coast, Oban, and Skye; in thirty to thirty-five fathoms, 
Loch Fyne, Mull, and Moray Firth; in forty-five to 
fifty fathoms, Zetland, and in ninety fathoms off Mull 
(M‘Andrew and E. F.). It occurs on both sides of 
England, both sides of Scotland, and both sides of Ireland. 
Lieutenant Thomas finds it in deep water, on a stony 
ground, in from thirty to one hundred fathoms on the 
north and north-east coast of Scotland. Mr. Jeffreys 
notes its occurrence on leaves of Fuci (Laminarie, pro- 
bably), in five fathoms. He has found the more conical 
variety at Fishguard. It ranges from Norway to the 
Mediterranean, and occurs fossil in the coralline crag. 


TROCHUS. 


Or 
= 
or 


T. exicuus, Pulteney. 


Small, conic, imperforated ; whorls with a prominent mar- 
ginal belt, above which are a few finer spiral costellz that are 
not simple; the interstices obliquely traversed by longitudinal 
raised lines ; apex rosy. 


Plate LX VI. fig. 11, 12. 
Trochus exasperatus, PENN. Brit. Zool. ed. 4, vol. iv. p. 126. — FLumine, Brit. 
Anim, p. 323. 

» minutus, §c. CHEMNITZ, Conch. Cab. vol. v. pl. 162, f. 1529 (probably). 

»  exiguus, PULTENEY, Hutchins, Hist. Dorset, p. 44.—Monr. Test. Brit. 
p. 277.— Maron and Rack. Trans. Linn. Soc. vol. viii. 
p- 156.—Racx. Dorset Catalog. p. 48, pl. 21, f. 4. — Turr. 
Conch. Diction. p. 190. — Brit. Marine Conch. p. 163.— 
Brown, Illust. Conch. G. B. p. 19, pl. 11, f. 27, 28.— Woon, 
Index Testac. pl. 29, f. 91. 

»  conulus, (not Linn.) Da Cosra, Brit. Conch. p. 40, pl. 2, f. 4.— 
Donoy. Brit. Shells, vol. i. pl. 8, f. 2. 

5, minutus, DitLW. Recent Shells, vol. ii. p. 797. 

»  erythroleucus, LAM. Anim. s, Vert. (ed. Desh.) vol. ix. p. 151.-— 

Han ey, Conch. Book of Species, p. 70. 

»  2nterruptus, Woon, Index Test. Suppl, pl. 6, Troch. f. 42 ? 

The name exasperatus was attributed to this species by 
Pennant, but was merely applied by him to the delineation 
of a shell which was otherwise unknown to him. On the 
same principle that we object to Gmelin’s habit of indiseri- 
minately bestowing Latin appellations upon all engravings 
of zoological subjects that he could not distribute among 
the ascertained and characterized species, we have here 
repudiated the prior name of an undefined shell. 

In our British specimens, the shell is simply conic, but 
varies considerably in the relative proportions of its length 
and base ; the lateral outlines are more or less rectilinear. 
It is tolerably strong, opaque, but little shinmg, and ranges 
in colour from tawny, or ashy fulvous brown, or olivaceous 
fulvous, to crimson red. In all cases, however, the apex, 
which is very small, and more or less acute, is invariably 


VOL. Il. 3 T 


506 TROCHIDA. 


of a crimson red, and the surface, especially the belts, are 
more or less stained, spotted, or articulated with pink ; 
when the ground is rose-coloured, it is generally speckled 
with white. There are six or seven volutions, which are 
tolerably long, since upon the penult whorl the length 
rather exceeds half the breadth of the superior edge; their 
increase, however, is not particularly rapid. They are 
flat, but margined below with a rather broad prominent 
rounded and spirally-striated belt, above which are three 
or four narrow spiral costelle, all which, as well as their 
broader and rather profound interstices, are subcrenately or 
subgranosely roughened by obliquely longitudinal elevated 
lines that are not very densely disposed, and are a little 
arcuated, especially along the groove above the marginal 
belt. These costelle, which upon the base are rounded, 
prominent, and often subarticulately painted with white, 
become likewise almost simple there, since the longitudinal 
lines, which in their intervals are much finer and more 
closely disposed than those upon the spire, are scarcely, 
indeed, manifest upon them. The base is rather com- 
pressed, very little rounded, except near the lip, and is 
sharply angulated at the edge: its axis is imperforated. 
The mouth, which is sometimes thickened in front by a 
linear callosity, is rather small, simple (not sculptured), 
of a squarish shape, and not much broader than long ; it 
occupies about one-third of the entire length of the shell, 
and about one-half the basal diameter. The outer lip is 
acute. The pillar, which is short, white, narrow, and 
almost rectilinear, sometimes exhibits, from the concavely 
appressed posterior inner edge, an obscure toothlike projec- 
tion near its lower end; it is not dilated above, but rather 
the contrary. The average length of our specimens is five 
lines, and their breadth at the base about three and a third. 


TROCHUS. 507 


We have hesitated to unite the Mediterranean pyrami- 
datus (Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 150.— 
Deters. Rec. Coquil. Lam. pl. 36, f. 2.—T". crenulatus, Pur- 
uippi, Moll. Sicil. vol.i. p. 176; vol. ii. p. 150.—T7. Maton, 
Payraup. Moll. Corse, p. 126, pl. 6, f. 5, 6.—TZ. tricolor, 
Risso, H. N. Europe Mér. vol. iv. p. 127, fig. 135%), al- 
though a more extended knowledge of the essential dif- 
ference between specific and varietal distinction, or the 
acquisition of intermediate examples, may render their 
union advisable. Our specimens of the latter shell are 
greatly more produced, have more numerous whorls, the 
lower ones of which are retuse rather than flat, are longi- 
tudinally painted, besides being articulately marked upon 
the raised sculpture, with brown or red spots, that do not 
extend to the articulated marginal belts, or else are 
obliquely striped (and upon the base likewise) with blackish 
brown longitudinal streaks. The interstitial striz, more- 
over, are so fine, as to be almost imperceptible, and the 
marginal belts are broader in proportion to the granulated 
spiral costelle. 

The animal has the sides of the foot, the tentacles, and 
lateral cirrhi tinged with madder red. The eye-peduncles 
are white, as is also the disk of the foot. 

This shell is almost confined to our southern shores. — It 
occurs at Guernsey (Barlee); Herm, Torquay, and Mar- 
gate (S. H.); in seven fathoms, alive, Weymouth Bay 
(M‘Andrew and E. F.); Cornwall (Dr. Turton) ; Bantry 
Bay (L. W. Dillwyn) ; Cork (Humphreys) ; Dublin Bay 
(Warren). The four latter localities are communicated by 
Mr. Jeffreys. 

It is not found to the north of the British isles, but 


ranges southward to the Mediterranean. 


508 TROCHIDA. 


T. srrrarus, Linneus. 


Small, conical ; whorls flat, with eight or nine spiral costelle, 
which are so little raised, that the volutions, especially the upper 
ones, might equally be termed sulcated, devoid of any prominent 
basal belt ; interstices, and oftentimes the costelle, longitudinally 
striated ; base broad, angulated at the margin, flat, or slightly 
concave, imperforated. 


Plate LXVI. fig. 5, 6. 


GuaLtTizR, Index Test. pl. 61, f. N.— CuHEemn. Conch. Cab. vol. y. pl. 162, 
f. 1527, 1528. 
Trochus striatus, Linn. Syst. Nat. ed. 12, p. 1230.—PuLtTenry, Hutchins, Hist. 
Dorset, p. 44.—Monr. Test. Brit. p. 278.—FLEmine, Brit. 
Animals, p. 323.—Brit. Marine Conch. p. 164.—Brown, 
Tilust. Conch. G. B. p. 19, pl. 11, f. 25, 26.—Dmiw. 
Recent Shells, vol. ii. p. 797.—Woop, Index Test. pl. 29, 
f. 90.—BLAINVILLE, Faune Frang. Moll. p. 266, pl. 10, 
f. 9.—Puivirrt, Moll. Sicil. vol. i. p. 176 ; vol. ii. p. 150. 
»  parvus, Da Costa, Brit. Conchol. p. 41. 
»»  conicus, Donov. Brit. Shells, vol. vy. pl. 155, f. 1. 
»  erythroleucus, Maron and Rack. (not Lamarck) Trans. Linn. Soe. vol. 
viii. p. 156.—Rack. Dorset Catalog. p. 48, pl. 18, f. 2. 
—Turt. Conch. Diction. p. 191. 
»,  depictus, DesHavES, Exped. Moree, Moll. p. 143, pl. 18, f. 23, 24, 
25 
» Sartori, ARADAS and MaGGiorx, Sunto di quatro mem., &c., fide 
Puivipri, Moll. Sicil. vol. ii. p. 225. 


We are not surprised that some of our British writers 
have not recognised the Linnean striatus in this long 
known shell, since the type of its founder exhibits a linear 
style of painting, which, although common enough in the 
Mediterranean, we have never observed in any of our 
native examples. The contour of this small, but strong, 
species is simply conic, and its lateral outline (an important 
character in this genus) is straightish or even a little 
retuse. The opaque surface is not much polished, but is 
generally a little glossy ; it displays a remarkable variety 
of patterns, but the two principal are the streaked and the 


TROCHUS. 509 


articulated. In the former, and this indeed is the ordimary 
painting, several wavy and obliquely longitudinal streaks 
of crimson or blackish brown, that are often clouded at 
one of their edges, not unfrequently interrupted, and often 
partially confluent, diversify the whitish or pale-coloured 
ground; these in our English specimens are almost inva- 
riably broad, and are replaced upon the inferior surface by 
a spiral articulation of the same colours. In one of our 
specimens of the latter, the ground is yellowish drab, and 
the raised sculpture is alternately dotted with a paler tint 
of the same hue, and with ashy-brown. The whorls are 
devoid of any peculiar marginal belt, but are spirally 
adorned with eight, or more frequently nine, elevated lines 
or very narrow costelle, that are but little raised, and ex- 
cept upon the base, where they are rounded and further 
apart, not particularly distinct, especially upon the upper 
portion of the spire, which might rather be termed striated 
or sulcated. The interstices, and very often the raised 
sculpture likewise, are minutely and very obliquely tra- 
versed by crowded longitudinal laminar lines. The volu- 
tions, which are six or seven in number, and terminate in 
an acute and often ruddy apex, are flat (except two or 
three of the apical ones) and occasionally somewhat retuse 
in the middle; they are moderately high, the length of 
the penult being about one half the breadth of the upper 
edge of that volution: the suture is indistinct. The base 
is broad (in our British examples), rather abruptly com- 
pressed, sharply angulated at the edge, and either flat, or, 
from the customary inferior projection of the basal edge, 
rather concave near the margin; the axis is imperforated. 
The aperture is squarish, as the excess (if any) of the 
breadth is but trifling; it occupies about half the basal 
diameter, and about one third of the length of the whole 


510 TROCHIDA. 


shell. ‘There are neither tubercles, crenee, nor any peculiar 
sculpture upon it ; the anterior portion is, however, thick- 
ened by a more or less distinct linear callosity. The 
outer lip is simple and acute; the pillar is straight, narrow, 
not much rounded nor dilated, and succeeded by a faint 
concavity. Ordinary specimens do not exceed two-fifths 
of an inch in length, and a third of an inch in breadth. 

Certain of the Mediterranean examples differ so widely 
at first sight from the variety which inhabits our own 
shores, as scarcely to be recognisable for the same species. 
In the typical or first described form, the whorls are a 
little swollen at the sutures, and the surface both above 
and below is radiated with continuous wavy and obliquely 
flexuous lines of black, that are often double upon the body- 
volution. In the produced variety the colouring has gene- 
rally an articulated arrangement, the whorls are narrower 
and longer, and as well as the base, which is destitute of 
the ordinary angulation, much more rounded. 

This shell is, as a British species, confined to our southern 
shores. It inhabits the laminarian zone, living on the 
leaves of Zostera, as at Herm and Torbay (S. H.), 
Guernsey (Barlee); Exmouth (Clark); on the Devon- 
shire and Cornish coasts ; common at Falmouth (Alder) ; 
in fifteen fathoms off the Land’s End (M‘Andrew) ; coast 
of Cork and Bantry Bay (Humphreys); Baltimore harbour 
(Allman). 

It does not occur to the north of Britain, but ranges 


southwards to the Mediterranean. 


TROCHUS. 511 


T. Monracut, Gray. 


Produced-conical, imperforated, small; whorls more or less 
rounded, with only about five or six distinctly separated spiral 
costella, and no marginal belt: the interstices striated longitu- 
dinally ; painting usually consisting of brown longitudinal lines 
on a yellowish white or ash-coloured ground, which are often so 
interrupted in the interstices, that the spiral costelle appear 
articulated. 


Plate LXV. figs. 10, 11. 


Trochus Montagui, GRAY in Index Testac. Suppl. pl. 6, Troch. f. 43. — Brit. 
Marine Conch. p. 255, f. 18. 
» striatus, ForBEs, Malac. Monens. p. 22, animal. 


This plain-looking little shell has a more elongated form 
than our other British T'rochi. It is of a produced 
conical figure, with the lateral outlines straightish, but 
more inclined to convexity than retusion. It varies in 
strength and lustre, but is never highly polished, and is 
composed of seven slightly convex volutions, whose elon- 
gation is by no means rapid (especially in the lower ones, 
which are rather high, their breadth above being only 
double their length), that are very abrupt in their declina- 
tion, and terminate in a small but obtuse point; a slight 
disposition to angularity sometimes exists beneath the 
suture upon the body-whorl. Five narrow and somewhat 
rounded costelle spirally encircle them ; whose intervals, 
which are broader, or at least as broad as the belts, are 
obliquely and closely traversed by most delicate longitu- 
dinal raised striule, that occasionally (and possibly always 
in the finer preserved individuals) cross the costelle like- 
wise ; a precisely similar sculpture is continued upon the 
base of the shell. There is no marginal belt, but two 
costelle often approximate at the outer margin of the 


512 TROCHIDA. 


base. The ground of the shell is dirty white, or ash- 
coloured, and the raised spiral sculpture is articulately 
painted with ochraceous or rufous brown lines, that pre- 
sent the appearance of longitudinal flexuous linear streaks, 
and, indeed, are occasionally continuous; besides these, 
there are in certain individuals, a few larger remote spots 
beneath the well defined sutures. The base, whose surface 
is a little rounded, especially near the lip, is angulated, 
though not very sharply, at its outer margin: its axis 
is imperforated. The aperture is subquadrate, and its 
breadth is not very much more than its length, the 
former being half that of the basal diameter, the latter 
occupying one-third of the total length of the shell. It 
has no peculiar sculpture ; the outer lip is simpie, acute, 
and somewhat arcuated anteriorly; the pillar is nearly 
perpendicular, not much spread, and becomes rather 
broader as it approaches the former. A rather fine speci- 
men measured three-eighths of an inch in length, and one- 
third less in breadth. 

The animal is white, with black markings. The head 
bears long white tentacula and white eye-peduncles, with 
black eyes. The capital lobes are mmute. The neck- 
lappets are white; the sides of the foot much marked with 
black. There are three slender white cirrhi on each side. 
The foot is lanceolate with obtuse angles anteriorly. 

So far as known this Zvochus is almost peculiarly 
British, and even on our shores is not found everywhere. 
On the east coast of England it is recorded by Mr. Bean 
from Scarborough. On the south it ranges to the Channel 
Isles, where it is dredged at Herm (S. H.); im from seven 
to twenty fathoms west bay of Portland (M‘Andrew and 
E. F.); Exmouth, Fishguard (Jeffreys) ; not rare in the 
Irish sea; in fifteen to twenty fathoms on the Welsh 


TROCHUS. 513 


coast, and in twelve to twenty-five on the Manx coast ; 
in from fifteen to ninety fathoms among the Hebrides 
(M‘Andrew and E. F.), where it has been taken in 
many localities by Mr. Jeffreys; Lamlash bay, Arran 
(Alder) ; in fifty fathoms off Cape Wrath, and in forty- 
five fathoms off Fair Island (M‘Andrew); in seven fathoms 
off the Dudgeon; in thirty-five fathoms, Buchaness ; in 
from seven to forty fathoms around the Orkneys, “ the 
individuals are not numerous anywhere; generally in deep 
water or stony ground” (Thomas); Portmarnock (War- 
ren); in ten fathoms Bantry bay, and sixty fathoms off 
Cape Clear (M‘Andrew). The only foreign locality re- 
corded is Vigo bay in Gallicia, where it was dredged 
by Mr. M‘Andrew in May, 1849. 


T. rumpus, Montagu. 


Small, perforated ; whorls ventricose, more or less subscalari- 
form ; spiral strize extremely numerous, and very delicate : 
markings linear, flexuous, and somewhat interrupted. 


Plate LXV. figs. 8, 9, and Animal, plate D D. fig. 2. 


Trochus tumidus, Monv. Test. Brit. p. 280, pl. 10, f. 4.— Maron and Rack. 
Trans. Linn. Soc. vol. viii. p. 153. — Rack. Dorset Catalog. 
p. 48, pl. 16, f. 9,10.— Turr. Conch. Diction. p. 187. — 
Fem. Brit. Anim. p. 822. — Forges, Malac. Monens. p. 23 
(animal). — JoHnsron, Berwick Club, vol. 1. p. 265.— 
Macem. Moll. Aberd. p. 133.—Brit. Marine Conch. p. 161. 
—Brown, Illust. Conch. G. B. p.18, pl. 11, f. 2, 3.—Woop, 
Index Testac. pl. 28, f. 41. — Buarnv. Faune Frang. Moll. 
p. 272.—Hanu. Young Conch. p. 70. 
5  patholatus, Dituw. Recent Shells, vol. ii. p. 776. 
Rackettii, Pavraup. Moll. Corse, p. 128, pl. 6, f. 9, 10 ? — PHwipP1, 
Moll. Sicil. vol. ii. p. 153. 
nitens (fossil) Woopwarpb, Geol. Norf. pl. 3, f. 10. 
»  Nassaviensis, REcLuz, Revue Zool. Cuvier. 1843, p. 107. 
2 Margarita undulata, var. Trochiformis, Forbes, Ann, Nat. Hist. vol. xix. p. 97. 
—Fry. Skenea Serpuloides, Maceit. Moll. Aberd. p. 135 (fide 
Jeff. from type). 


This shell, indeed, bears some likeness to a pygmy 


VOL. II. Sonu 


” 


3° 


514 TROCHIDA. 


cinerarius, but the more scalariform mode of its gyration 
will readily distinguish it. It has been conjectured to be 
identical with the 7’. Nassaviensis of Chemnitz (Conch. 
Cab. vol. v. pl. 171, f. 1676.—7. patholatus, Guuu. Syst. 
Nat. p. 3574), but even if so,—a conclusion certainly not 
warranted by the figure,—the extremely imperfect definition 
of that shell would invalidate the claim of priority. 

The general shape ranges from rather obtusely conic 
to orbicular conoid; the base is generally more or less 
flattened, rarely a little convex near the mouth, and mode- 
rately shelving; the lateral outline is somewhat arched, 
and more or less scalariform. The shell is small, rather 
strong for its size, sometimes opaque, sometimes very 
slightly diaphanous, more or less dull, and of a pale ash- 
colour, variegated with more or less interrupted oblique 
and wavy lines of chestnut, brown, or greyish brown, 
which often become partially or entirely obsolete upon 
the base; im certain individuals, the continuity of the 
lines being no longer perceptible, the surface appears spi- 
rally articulated with rather distant coloured minutely 
oblong dots; in others there are additional squarish spots 
below the sutures. Both the upper and lower surfaces are 
encircled with fine and numerous raised lines, which are 
generally fewer, coarser, and more distant in the northern 
examples. There are frequently, besides, some fine spiral 
striule in the interstices, and the whole shell is microsco- 
pically traversed by obliquely longitudinal and most densely 
disposed wrinkles. There are six volutions, which increase 
with moderate quickness; the apex is tolerably acute ; 
the next whorls more or less rounded; the two or three 
last are narrowly angulated below the suture, and then 
become flattish and but little shelving; there is often, 


besides, a very slight but diffused retusion upon the body- 


TROCHUS. 5S 


whorl, which causes the basal outline to appear submargi- 
nated and bluntly subangular. In certain of the southern 
examples, the angular character of the shell becomes almost 
entirely lost, and these individuals entirely agree with the 
specimens of Rackettii forwarded to us by Dr. Philippi. 

The aperture is squarish, and broader than it is high ; 
the length in general is not equal to that of the spire, the 
breadth is equal to, or rather exceeds, half the basal 
diameter. There is no particular sculpture; the nacre is 
generally brilliant; the outer lip is acute; the pillar lip 
rather oblique, straightish, a little incurved above, gene- 
rally reflected there, and sometimes so much so as par- 
tially to conceal the small but profound umbilicus, the 
mouth of which latter is smooth, large, and abrupt. Our 
largest specimen (a Shetland one) measures four lines and 
a half in length, and the same at the base. 

The animal is of a white or yellowish white hue, 
speckled with black or lead-coloured markings. Its muzzle 
is rather broad, finely crenated at its edges, and is marked 
with dark transverse lines. The tentacles are setaceous, 
white, and (as well as the lateral filaments) as if finely 
frosted, being covered with fine cilia. The eye-peduncles 
are white, the eyes dark. The head-lobes are rather large 
and even. The neck-lappets have even edges and are 
white. The sides of the foot are more or less mottled and 
streaked with dusky colouring. The disk of the foot is 
oval, rounded in front and obtuse behind. 

In the curious variety (?) from the Zetland seas, de- 
scribed in the 19th volume of the ‘“ Annals of Natural 
History” as a form of Margarita undulata, the markings 
of the foot are brownish, the foot itself angulated in front, 
and the tentacles more subulate and much more strongly 
ciliated. These characters would seem to indicate specific 


516 TROCHIDA. 


distinctness. The only specimen of the shell taken was in 
the cabinet of Mr. M‘Andrew, but unfortunately has been 
accidentally destroyed. 

Abundant everywhere all round our shores, inhabiting 
for the most part the coraline zone, but occasionally rang- 
ing from seven to as deep as sixty or even eighty fathoms. 
It ranges throughout the western seas of Europe, and is 
found fossil in the red crag. 


T. crverarius, Linneus. 


Whorls flattish, with coarse raised spiral striz, and fine linear 
iron-grey markings on an ash-coloured ground; axis with a 
rather narrow perforation. 


Plate LXV. fig. 1, 2, 3, and (Animal) Plate D D, fig. 1, and 1 a. 


LisrER, Hist. Conch. pl. 641, f. 31. 
Trochus cinerarius, LINN. (not Born) Syst. Nat. ed. 12, p. 1229.—Donov. Brit. 

Shells, vol. iii. pl. 74,top and bot. figs—Monv. Test. Brit. 
p- 284.— Torr. Conch. Diction. p. 187. FiEem. Brit. 
Anim. p. 322.—Forsss, Malac. Monens. p. 23 (animal).— 
Jounst. Berwick, Club, vol. i. p. 264.—Maceity. Moll. 
Aberd. p. 133 (chiefly).— Brit. Marine Conch, p. 161.— 
Brown, Ill. Conch. G. B. p. 18, pl. 11, f. 5, 8—MU er, 
Zool. Danic. pl. 102, f. 1 to 4.—CuEmn. Conch. Cab. vol. v. 
p- 117, pl. 171, f. 1686.—Drmu. Recent Shells, vol. ii. p. 
779.—Woop, Index Test. pl. 29, f. 49.—Lam. Anim. s. 
Vert. (ed. Desh.) vol. ix. p. 149.—GrvxENs, Conch. Cab. 
ed. 2, pl. 12, f. 119, 120.—Hanu. Young Conch. p, 70.— 
Loven, Index Moll. Scand. p. 20. 

»  Uneatus, DA Cosra, Brit. Conch. p. 43, pl. 3, f 6.—PuLTENry, Hut- 
chins, Hist. Dorset, p. 44.—Maron and Rack. Trans. Linn. 
Soe. vol. viii. p. 1538.—Racx. Dorset Catalog. p. 48, pl. 16, 
1 ls ee 

»  perforatus, SmirH, Mem. Werner. Soe. vol. viii. p. 99, pl. 1, f. 3, 4.— 
Brit. Marine Conch. p. 161.—Browy, Illust. Conch. G. B. 
18 le alas 2 IE 

55  inflatus, BLAINVILLE, Faune Frang. Moll. p. 275, pl. 11, £. 5 (probably). 

,, Uineolatus, Pottez and Micu. Gal. Douai, Moll. vol. i. p. 334, pl. 30, 
f. 8, 9. 

, littoralis, Brown, Illust. Conch. G. B. p. 18, pl. 11, f. 1, 4. 

,,  electissimus, BEAN, Brit. Marine Conch, p. 264. 


TROCHUS. 517 


There are two marked varieties of this common shell, 
which differ from each other in shape, and the consequent 
dilatation or contraction of the profound umbilicus. The 
one is rather bluntly conic, with a very small perforation ; 
the other is much less elevated, expanded at the base, 
and with the aperture of the umbilicus commensurately 
enlarged; the latter form much resembles the young state 
of the former, but vies with adult specimens in size. 

The whorls are six in number, well defined, but only 
slightly convex; in some of the flattened specimens, 
indeed, a slight concavity is perceptible towards, but not 
adjacent to, the suture; each volution is, as it were, dis- 
tinctly raised out of the preceding one. The apex is 
extremely fine and small, and is very often tinged with 
yellow or a warm chestnut colour; the increase of length 
in the gyration is rather quick. The base is more or less 
flattened, and the basal outline is consequently more or 
less angulated. 

Its sculpture, and its peculiar style of painting, form its 
most salient characteristics. The shell is strong, opaque, 
and rather dull, or but little glossy, with the surface 
roughened by several spiral belts, that vary greatly in 
number and thickness, but are always narrower than their 
interstices. There are generally from six to nine upon the 
penult whorl. These spiral lines are continued upon the 
base, where they become more approximate and _ less 
prominent. The interstitial spaces are smooth, or almost 
so. The entire exterior, which is greyish, cinereous, or 
yellowish ash-colour, is obliquely traversed by flexuous 
linear markings of iron- or slate-grey, smoke-colour, or 
more rarely of reddish brown, which are closely disposed, 
run in an opposite direction to the lines of growth, and do 
not become confluent, except occasionally upon the base 


518 TROCHIDA. 


of the shell. The aperture is subquadrate, and broader 
than, or at least as broad as, it is long; the interior is 
silvery white, and not at all grooved; the outer lip is 
simple, acute, and very oblique; the columella is straightish, 
white, and devoid of all tubercles, crenze, or other mark- 
ings. The umbilical cavity is white, and in one of the 
flat varieties is delicately chased with close-set longitudinal 
lines. In two adult individuals, which each measured 
seven lines at the base, the length of the conical variety 
was eight lines, of the depressed variety, barely half an 
inch. In neither case have we given the extremes; in the 
latter form, especially in the young, we have seen examples 
of which the basal diameter was actually, or all but, twice 
the length of the shell. In the variety electissimus, the 
minute longitudinal striule, that are occasionally visible in 
the interstitial spaces of the more typical form, appear, 
when highly magnified, to regularly traverse the elevated 
sculpture likewise. 

The animal is white, with a yellow tinge, minutely 
speckled with opaque dots. The head is white and yellow; 
its muzzle is broad and crenated at the edge; the tenta- 
cula are large, subulate, and, under the lens, minutely 
ciliated ; they are white, with obscure, dusky rings; be- 
tween them are two well-developed, crenated head-lobes, 
which approach more nearly to each other than those of 
the next species, ‘The eye-peduncles are stout and rather 
long; the eyes are black. The neck-lappets are white ; 
the inner or columellar lobe has a fimbriated edge, that of 
the outer one is plain (they are both represented as cre- 
nated in the figure by mistake). The mantle is even- 
edged and white with shght dusky markings. The lateral 
cirrhi are white, with minute lobes at their bases, and are 


larger than in wmbilicatus. The foot is oblong, rounded in 


TROCHUS. 519 


front, and as if villose at the edges. The operculum is 
bright yellow. Loven represents the central denticle in 
the tongue of this species as greatly enlarged below and 
narrowly contracted beneath the slightly-incurved but not 
mucronated apex, and the laterals as being very strongly 
hooked. 

Abundant everywhere on all our coasts, living among 
fuci on the lower belt between tide-marks, very plentiful 
in the laminarian zone, and occasionally occurring as deep 
as fifteen or even twenty fathoms. It varies much, and a 
form is rarely found which may prove to be a hybrid 
between this and the last. It ranges northwards to the 
shores of Finmark, and southwards to the coasts of Spain. 
It occurs fossil in the red crag and pleistocene deposits. 
On some parts of our coast it is called the Dog- 
Periwinkle. 


T. umsrticatus, Montagu. 


Orbicular-conoid, generally perforated ; spiral sculpture not 
granular, no marginal belt; painted with purplish red linear 
stripes on a yellowish or greenish white ground. 


Plate LXVI. fig. 1 to 4, as umbilicalis. 


Trochus umbilicaris, PENN. (not Linn. nor Lam.) Brit. Zool. ed. 4, vol. iy. 
p- 126, pl. 80, f. 106. 
»  wmbilicalis, DA Costa, Brit. Conch. p. 46, pl. 3, f. 4. 
» oblique radiatus, CHEMN. Conch. Cab. vol. v. p. 117, pl. 171, f. 1685 
(not well). 
»  cinerarius, PULTENEY (not Linn.), Hutchins, Hist. Dorset. p. 44.— 
Buiainy. Faune Frang. Moll. p. 277, pl. 11, f. 10. 
»  wmbilicatus, Mont. Test. Brit. p. 286.—Maron and Rack. Trans. 
Linn. Soc. vol. viii. p. 153.—Turr. Conch. Diction. 
p- 186.——Fiemine, Brit. Animals, p. 322.—ForBgs, 
Malac. Monens. p. 24, animal.—Macerity. Moll. Aberd. 
p- 324.—Brit. Marine Conch. p. 160.—Brown, Illust. 
Conch. G. B. p. 18, pl. 11, f. 9, 11.—Woop, Ind. Testac. 
pl. 29, f. 48.—Hantzry, Young Conch. p. 70. 
5  obliquatus, Dittw. Recent Shells, vol. ii. p. 779. 


520 TROCHIDA. 


As Da Costa wilfully changed the name of this shell, 
even while he regarded it as the cinerarius of Linneus, we 
adopt on reflection the name by which Montagu distin- 
guished it ; since he clearly pointed out that it was not the 
umbilicaris of Linneeus, for which Pennant had taken it. 

A considerable degree of likeness exists between this 
species and cinerarius, from which its colour, the broader 
style of its painting, and the less numerous belts of its 
base serve to distinguish it. 

It is a strong, opaque, and almost Justreless shell, of an 
orbicular-conic form, convex lateral outlines, a small and 
blunted apex, and a somewhat flattened base, that is 
rounded-off but yet subangulated at its edge. Upon a 
ground of dull greenish white, or pale olivaceous yellow, 
it is closely flexuously and rather obliquely streaked with 
narrow stripes (not lines) of purplish red or reddish slate- 
colour, which do not run parallel to each other, but diverge, 
for the most part, further apart at the lower part of the 
whorls, frequently become confluent above, and are often 
interrupted, and occasionally somewhat reticulated, upon 
the base. ‘There are several simple raised spiral lines, that 
for the most part are decidedly narrower than their inter- 
stices, are sometimes prominent, yet at times so ill-defined 
at their lower edges that the shell seems imbricato-sulcated ; 
these are replaced at the basal margin by simple striz 
(which are often obsolete), and are again renewed upon 
the base, where the belts or sulci are by no means numer- 
ous, and rarely much elevated. There are about five and 
a half moderately increasing volutions, that are rather de- 
pressed in proportion to their breadth, much shelving, and 
rather more convex below than above; the umbilicus is 
profound, moderate in size, and margined with white. The 
mouth is rather large, and decidedly broader than it is 


TROCHUS. 52 it 


long; in general it occupies half the length of the shell, 
and more than half of the basal diameter; it is pearly 
within, and is not distinguished by any sculpture. The 
outer lip is acute, and generally bordered with rather a 
wide strip of the external colouring, with a predominancy 
of dirty green, which latter tint is more particularly ap- 
parent at the base of the short and not particularly oblique 
columella, which is white, subarcuated above, a little 
reflected, and somewhat flattened behind. The size is 
about that of the flattened variety of cinerarius. 

We have taken alive in the islet of Herm, near Guernsey, 
a very remarkable variety which exhibits no trace of a per- 
foration when adult, and only a slight indication of one 
when young. Except that it is rather more elevated, and 
that the painting of the smoother and rather more convex 
base displays a more reticulated appearance than in the 
majority of individuals of the commoner form, we can 
discern no difference in the characteristics. 

The animal is of a general dusky greenish purple hue. 
The snout is finely crenated at its edge and is of a greenish 
colour, with transverse purple lines. The tentacula are long 
and setaceous, minutely ciliated, and conspicuously ringed 
with purple. Between them are two well-developed but 
well-separated crenated head-lobes. The eye-peduncles are 
stout and greenish-white, with greenish-purple eyes. The 
neck-lappets are pale, marked with greenish opaque yellow 
dots and purple: the inner one has a fringed margin, the 
outer is even-edged. The lateral cirrhi, which, though 
long, are not so long as in cinerarius, are finely rayed 
with purple, and have each a white tubercle and minute 
mucronated process at the base: there are three on each 
side. The sides of the foot are closely lineated with 
greenish brown or rich purple; the lateral membranes 


VOL. Il. ax 


yap TROCHIDA. 


above them are paler and more of a greenish yellow hue ; 
the disk of the foot is pale tawny white, oval, rounded at 
each extremity, finely and minutely fringed at the edges, 
and marked with a groove down the centre. This groove 
is conspicuous also in the foot of the preceding species. 
The dentition appears slightly different from that of 
cinerarius. 

This is a littoral shell, living on fuci and rocks, between 
tide-marks and usually forming a zone above that of 
cinerarius. Though very abundant wherever it occurs, its 
distribution is peculiar, being confined to our southern 
and western coasts. It does not appear to range north- 
wards of the Hebrides, and is absent from the entire eastern 
side of Great Britain. It ranges all round Ireland, and 
is abundant on the shores of the Irish seas. Its southern- 
most recorded foreign locality is Vigo Bay (M‘Andrew). 
It is not known fossil. 


T. Macus, Linneeus. 


Orbicular-conic; whorls scalariform, nodulous above, with fine 
spiral strive, and an inferior marginal belt ; umbilicus very large. 


Plate LXV. fig. 6, 7, and (Animal) Plate D D, fig. 3. 


Knorr, Délices des Yeux, pt 6, pl. 27, f. 4. 

Trochus Magus, Linn. Syst. Nat. ed. 12, p. 1228.— Penn. Brit. Zool. ed. 4, 
vol. iv. p. 127, pl. 80, f. 107. — Putrrenry, Hutchins, Hist. 
Dorset, p. 44.— Donov. Brit. Shells, vol. i. pl. 8, f£ 1.— 
Mont. Test. Brit. p. 283.—Maron and Rack. Trans. Linn. 
Soc. vol. viii. p. 151.— Rackxerr, Dorset Catalog. p. 48, 
pl. 16, f. 1, 2.— Turr. Conch. Diction. p. 186, f. 64. — 
Friemine, Brit. Anim. p. 321.— Fores, Malac. Monens. 
p. 23, animal.—Brit. Marine Conch. p. 160.—Browy, Illust. 
Conch. G. B. p. 17, pl. 11, f. 12, 15. — Born, Testac. Mus. 
Ces. p. 330. — CHEMN. Conch. Cab. vol. y. p. 101, pl. 171, 
f. 1656, 1657, 1659; vol. xi. p. 163, pl. 196, f. 1886. — 
Ditiw. Recent Shells, vol. ii. p. 774.—Lam. Anim. s. Vert. 
(ed. Desh.) vol. ix. p. 130.— Woop, Index Testac. pl. 28, 
f, 34. — Buarny. Faune Frangaise, Moll. p. 280, pl. 10, a, 


TROCHUS. jaa 


f. 1 to 4. — Desu. Encycl. Méth. Vers, vol. ii. p. 1072, — 
Gervens, Conch. Cab. (ed. 2) pl. 11, f. 84; pl. 12, f. 88, 
96, &c.—Puriprt, Moll. Sicil. vol. i. p.179 ; vol. ii. p. 152. 
—Hantery, Young Conch. p. 67. 

Trochus tuberculatus, DA Cosa, Brit. Conch. p. 44, pl. 3, f. 1. 


This is a solid opaque and rather lustreless shell, of a 
somewhat depressed orbicular-conical form, with a scalari- 
form but not arcuated lateral outline. The exterior is varie- 
gated with various tints and intensities of reddish, liver, rose 
colour, or more rarely with dark yellow, on a ground of 
impure white; the general style of painting consists of 
patches of the darker colour radiating from the sutures, 
succeeded by, or passing into, angularly flexuous, and often 
interrupted or subreticulated streaks upon the base of the 
body; there are generally, also, two or three narrow 
articulated fillets upon the lower portion of the larger 
whorls, and sometimes upon the base likewise. Beneath 
the sutures the surface is adorned with rather large 
flexuous irregular blunt knobs, that are longer than they 
are broad, but are not unfrequently almost obsolete ; 
below them lie a few scarcely raised rather distant spiral 
strie. A somewhat broader belt margins the base of each 
of the whorls; above it is a rather deep sulcus, that is 
minutely honey-combed by close-set obliquely longitudinal 
lamelle. Numerous spiral lines, that are almost belts 
upon the younger shells (on which, for the most part, the 
subsutural knobs are not developed, but the upper spiral 
lines are often subgranose), encircle the base; these usu- 
ally become obsolete in aged individuals. There are six 
moderately enlarging rather narrow scalariform volutions, 
which, flattened and subangulated above, flattish and but 
little shelving at the sides, and defined by a very strongly- 
marked suture, terminate in a small and rather pointed 
apex. The base is plano-convex, and moderately shelving ; 


524 TROCHIDA. 


the umbilicus is large, deep, funnel-shaped, white, and 
externally defined by a spiral hollow. The aperture is 
squarish, and much broader than it is long; its vertical 
length is about two-fifths that of the entire shell; its 
breadth is about half the basal diameter; there is no 
particular sculpture; the nacre is usually tinged with 
pink or flesh-colour. The outer-lip is acute; the pillar is 
white, rather obliquely subrectilinear, yet a little incurved 
posteriorly, and meets the whorl above it at nearly right 
angles. The vertical height of a large specimen, whose 
base measured all but fourteen lines, scarcely exceeded 
two-thirds of an inch; these proportions are, however, 
extreme, as the general length is only one-third less than 
the basal diameter. 

The beauty of the hues of the shell in this Trochus, 
is exceeded by the painting of the animal, which rejoices 
in a skin of most vivid colouring. The muzzle is dark 
pinkish blue, speckled with opaque white towards its 
extremity. The subulate tentacles are pale yellow, with 
purple rings, darker above than below. The head-lobes 
are very large, more or less crenated, of a rich orange, 
sometimes approaching scarlet, with a border of bright 
yellow. The eye-peduncles are large, and of an orange 
colour ; the eyes are vivid blue. The neck-lappets are 
orange, striped with flake white; the mner one is crenated 
at the edge. The lateral veils are of a sulphur yellow 
hue, with white specks, and are minutely rugose, with 
white dendritic papille. On each side are three pale 
tawny or yellow filaments, ringed with white; at their 
bases are white tubercles. The sides of the foot are 
closely and minutely speckled with purple, white and 
yellow, paler at the edges. The disk of the foot is elongated 


eval, rounded in front, of a yellowish-white hue, and has 


TROCHUS. Eat) 


minutely fringed margins; a groove runs down the anterior 
half of its length. The rows of denticles on the lingual 
riband of this species are set very obliquely on each side 
of the central one, which has a broad base, a narrow but 
not contracted neck and a broad but shallow hook. The 
general character of the dentition approaches, but is very 
distinct from, that of cinerarius. 

This fine shell is found all round our coasts, though 
not everywhere in equal abundance. It is most vividly 
coloured in youthern localities. A white variety was 
noticed by Mr. Jeffreys in the Hebrides and Zetland. It 
lives in from three to twenty-five fathoms water, and is 
most abundant in from ten to fifteen fathoms. It is not 
known north of the British Isles, but ranges southwards to 
the Mediterranean. It has not been found fossil in our 
tertiaries. When artificially decorticated, so as to expose 
the nacre, it is sometimes made into ornaments, such as 
brooches and bracelets, with fine effect. 


T. tinzatus, Da Costa. 


Orbicular-conoid, strong, smooth, imperforated ; painted with 
flexuous linear markings. 


Plate LXV, fig. 4, 5, as T. crassus. 


Turbo lineatus, Da Costa, Brit. Conch. (1778) p. 100, pl. 6, f. 7.—Donov. Brit. 
Shells, vol. ii. pl. 71. 
Trochus crassus, PULTENEY, Hutchins, Hist. Dorset (1799), p. 44.—Monr. 
Test. Brit. p. 281.—Maron and Rack. Trans. Linn. Soc. 
vol. viii. p. 154.—Rack. Dorset Catalog. p. 48, pl. 17, f. 3, 7. 
—Turr. Conch. Diction. p. 188.—FLEmine, Brit. Anim. p. 
322.—Brit. Marine Conch. p. 162.—Brown, Illust. Conch. 
G. B. p. 19, pl. 11, f. 6, 7.—Ditiw. Recent Shells, vol. ii. 
p- 796.—Woop, Index Test. pl. 29, f. 87. 
Monodonta lugubris, Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 180.—DeELEs. 
Rec. Coquil. Lam. pl. 36, f. 7. 
Trochus punctulatus, BuAiny. Faune Frangaise, Moll. p. 270, pl. 11, f. 2. 
Monodonta crassa, Maceiuu1y. Moll. Aberdeen. p. 325. 


526 TROCHID®. 


This very aberrant form of Trochus, differs so much 
from the rest of its British congeners, as to be readily dis- 
tinguished by the veriest tyro in Conchology. It is strong, 
solid, opaque, with a coarse surface, yet smooth both 
above and below, except in the young, which is obscurely 
suleated or closely girt with depressed obsolete costelle, 
vestiges of which are frequently visible upon the smaller 
volutions of the adult shell. The shape is conoid, or orbi- 
cular conoid, and the lateral outlines are more or less 
convex. The exterior is, for the most part, of a yellowish 
ash or pale fawn-colour, subreticulately variegated with 
more or less crowded zigzag lines of a purplish black, 
whose angles are small and frequent. Slightly eroded 
examples, and these are the more common, exhibit an 
almost uniform tint of brownish black. The volutions, 
which terminate in a small, but generally abraded, blunt 
apex, are about six in number; they quickly enlarge, for 
the last whorl is longer than the whole spire, are high, 
the length of the penult being at the least equal to one 
half its breadth at the superior suture, and are decidedly 
rounded or even tumid, although just below the delicate 
but well-marked sutural line they are a little retuse. The 
base of the shell is rounded, yet a little compressed, espe- 
cially upon the broad semicircular patch of white or 
ochraceous orange that lies behind the pillar-lip, nearly in 
the centre of the disk ; this appears as if worn flat, and is 
oceasionally bordered with bluish green. The basal cir- 
cumference is not angulated ; the axis is imperforated, but 
often exhibits, particularly in the more aged individuals, 
an indentation which resembles an incipient umbilicus, 
The mouth, which is very large, since even in mature indi- 
viduals, it occupies nearly one half of the entire length of 


the shell, and in the young a still larger proportion of it, 


TROCHUS. OG 


has a somewhat rounded figure; the breadth, which 
scarcely exceeds the length, is superior to one half of the 
basal diameter. The outer lip is simple, acute, and rather 
broadly margined with black or dusky green. It is con- 
siderably and continuously arcuated, yet is less convex in 
front than behind; it recedes so greatly anteriorly as to 
expose a large portion of the internal silvery nacre. The 
white pillar-lip is much bent, being subangulately curved 
in the middle, the nacre is only spread, and that too, 
sparingly upon the anterior portion of it. The pillar, 
which is broad, appressed, slightly oblique, and often a 
little concave in front, has the line of demarcation between 
it and the surrounding area almost entirely obsolete ; it is 
furnished with a somewhat tooth-like projection at its 
inner edge, and sometimes (yet rarely) with a single indis- 
tinct transverse groove nearly opposite the middle of the 
umbilicoid indentation. The ordinary diameter is about 
an inch in both directions, a size frequently much exceeded 
in those worn and aged individuals that are generally 
rejected from our cabinets. 

The operculum differs from that of its allies, and is 
loosely spiral in the centre. 

The animal has the muzzle finely serrated at the margin, 
and of a dusky hue; the head-lobes are semicircular, and 
at their bases the head is marked with closely-set black 
lines. ‘The tentacula are long, subulate, and ringed with 
closely-set fine black annulations. The eye-peduncles are 
stout, edged with yellow at their extremities, and bear 
black eyes. The neck-lappets are pale green, the inner one 
fringed at the edge, the outer one plain. The lateral veils 
are of a pale dull green hue, with a drab fringe at their 
margins; on each side there are three long filiform, ex- 
tremely delicate cirrhi, white, annulated with dusky and 


528 TROCHIDA. 


having a white or yellow tubercle at the base of each. The 
sides of the foot are greenish yellow, marked with dark 
close-set interrupted lead-coloured lines, mingled with fine 
yellow opaque dots. The disk of the foot is oval, moderately 
elongated, rounded at both ends; grooved medially and 
anteriorly, of a dusky drab colour, with fine anastomosing 
yellowish white lines, and a fine light drab fringe at the 
edge. This account of the animal is extracted chiefly from 
the notes of Mr. Clark. 

The range of this species is south-western and western. 
It inhabits the Channel Isles (S. H.); is frequent on the 
Devon and Cornish coasts, and along the southern and 
western shores of Wales. It is found round the southern, 
eastern, and western coasts of Ireland, extending north- 
wards as far as 544° N. lat. (Thompson). It is a littoral 
shell, always found between tide-marks. Mr. Jeffreys has 
a monstrosity, found at Exmouth by Mr. Clark, in which 
the operculum is irregularly spiral. It is not known as a 
British fossil. It ranges along the south-western coast of 


Europe. 


T. unputatus, Sowerby. 


Small, of an uniform pink or flesh-colour, not variegated ; 
whorls with subsutural longitudinal undulations, and in general 
with spiral costelle, but no marginal belt : rather a large umbi- 
licus. 


Plate LX VIII, fig. 1, 2, and Plate LX XIII, fig. 5, 6. 


Margarita striata, LEAcH, in Appendix to Ross’s Voyage to North Pole (inade- 
quately defined ; but from types).—Gray, Zoolog. Journ. 
vol. ii. p. 567. 

Turbo carneus, Low¥, Zoolog. Journ. vol. ii. p. 107, pl. 5, f. 12, 13.—Brit. 

Marine Conch. p. 170. 

Margarita carnea, SowERBY, Malacolog. Magaz. p. 25 ; Conch. Illust. Marg. 
f. 9.—Brit. Marine Conch. p. xxxvii—Brown, Illust. 
Conch. G. B. p. 17, pl. 10, f. 36, 37. 


TROCHUS. 529 


Margarita undulata, SowErsy, Malacalog. Magaz. p. 26 ; Conch. Illust. Margar. 
f. 4.—GouLp, Invert. Massach. p. 254, f. 172.*— 
REEVE, Conch. System. pl. 221, f. 4. 

Turbo incarnatus, CourHouy, Boston Jl. Nat. Hist. vol. ii. p. 98, pl. 3, f. 13. 


By regarding Margarita as only a section of this genus, 
we are compelled to prefer the later, but more characteristic 
designation of Sowerby, to that bestowed by Lowe upon 
the young of this species, since the epithet carneus has 
already been assigned to a Trochus in the pages of 
Gmelin. The occasional entire or partial absence of the 
spiral sculpture is a remarkable feature of this widely 
diffused and variable species. The shape in general is 
suborbicular and depressed conical; in large foreign ex- 
amples it is sometimes almost conoidal; the lateral outlines 
are more or less arched. ‘The texture is not particularly 
thin, but in most individuals (from our own shores) is a 
little translucent; the surface is but moderately lustrous, 
and of an uniform colour, ranging in tint from a slightly 
empurpled rose to yellowish flesh-colour: the fry are quite 
white, hence the apex of the adult is usually of a paler 
east than the rest of the exterior. Numerous short and 
wavy longitudinal folds emanate from beneath the strongly 
impressed, and often subcanaliculated, sutures, and densely 
disposed spiral costelle, that in general are broader than 
their intervals, each interstice being almost immediately 
filled up by a narrower riblet, for the most part encircle 
the upper area of the shell; the lower surface being either 
smooth or merely traversed by more or less obsoletely 
raised spiral striae. In one of our varieties the entire shell 
is destitute of costelle; in another the upper portion of 
the body-whorl alone is free from them; the folds, how- 
ever, are present in both. The riblets are sometimes pro- 
minent and rounded, sometimes plano-convex ; occasionally 


VOL. I. 3 Y 


530 TROCHIDA. 


almost beaded near the undulations. There are five rather 
narrow whorls, which rapidly enlarge from a fine and 
rather acute apex; they are peculiarly well-defined, each 
base being suddenly perpendicular whilst the portion above 
is convexly shelving: at times the volutions are slightly 
flattened above likewise, so as to appear subscalariform. 
The base is a little compressed, yet tolerably convex: the 
umbilicus, which is profound, rather large, and funnel- 
shaped, has a somewhat abrupt commencement, and is at 
times bounded by a spiral line. The aperture, which has 
a roundish subquadrate contour, usually occupies half the 
entire length, and half the basal diameter, of the shell. 
Both lips are acute, simple, and arched; the anterior 
recedence of the projecting outer one is not considerable ; 
the pillar, which is short, narrow, and very oblique, curls a 
little towards the umbilicus. 

The basal diameter rarely exceeds the fifth of an inch in 
native examples; an individual of the smooth variety from 
Greenland measured five lines across. 

The animal, which we have taken alive, and on which 
Mr. Alder has communicated his notes, is entirely white or 
yellowish white, with the exception of the black eyes and 
dark spots at the base of the lateral cirrhi. The head 
terminates in a broad crenated muzzle. The head-lobes 
seem to be obsolete; the tentacula are long, subulate, and 
finely but conspicuously ciliated; the eye-peduncles are 
rather short ; the neck-lappets appear to be small; there 
are five lateral cirrhi on each side, three in the region of 
the operculum and two anteriorly placed. The foot is 
large, rounded in front, somewhat obtuse behind, 

On the British shores this Moliusk is confined to the 
western and northern coasts of Scotland. It was first 
described as a native by Mr. Lowe, who found it at Oban. 


TROCHUS. 531 


It inhabits various depths of water from five to fifty 
fathoms, abounding most in from twelve to fifteen fathoms. 
Though widely diffused through the Hebrides, Orkneys, 
and Zetlands, it is not universally present in the regions, 
but occurs in patches of variable extent. The localities in 
which we have taken it most abundantly are Oban and 
Lerwick in Zetland; in the latter place it is frequent © 
among Modiole and Laminaria in seven fathoms water. 
The British localities are in the southernmost bounds of its 
range. It is an arctic species, ranging along the Scandi- 
navian, Greenland, and Boreal American shores, and is 
probably of western origin and comparatively late migra- 
tion, as we do not find it fossil in British tertiaries. 


T. mevicinus, O. Fabricius. 


Small, smooth, thin, umbilicated. 


Plate LXVIIL., fig. 4, 5, LX XIV. f. 10, and (animal) Plate CC. fig. 4. 


Turbo Helicinus, O. Fasr. (not Gmelin) Fauna Grenland. p. 393.—Puipps, 
Voyage to North Seas, p. 198 (probably). 
Trochus Neritoideus, GMEL. Syst. Nat. p. 83577.—Ditiw. Recent Shells, vol. ii. 
p- 780. 
Turbo margarita, Monv. Test. Brit. Suppl. p. 148.—Turv. Conch. Diction. p. 229, 
—Lowe, Zool. Journ. vol. ii. p. 107, pl. 5, f. 10, 11.— 
FLEeminé, Brit. Animals, p. 299.— Brit. Marine Conch. p. 169. 
Helix margarita, LAskEY, Mem. Werner. Soe. vol. i. p. 408, pl. 8, f. 5.—FLEM- 
ING, Encyclop. Edin. pl. 203, f. 9. 
Phorceus margarita, Risso, H. N. Europe Mérid. vol. iv. p. 133, f. 47 2—Mac- 
GILLIV. Moll. Aberd. p. 134. 
Trochus margaritus, GRAy, Zoolog. Journ. vol. ii. (name only).—Jounston, Ber- 
wick Club, vol. i. p. 265. 
Margarita vulgaris, Lzacu, MSS. in Sowerby, Conch. Magaz. p. 24.—SoweErsy, 
Conch, Ill. Margarita, f. 13.—Hant. Brit. Marine Conch. 
p. XXXVil. 
arctica, GouLD, Inyert. Massach. p. 255, f. 173*. 
Helicina, Mé6.ueEr, Index Moll. Grenl. p. 8.—Lovin, Ind. Moll. 
Scandin. p. 20. 
margarita, BRown, Illust. Conch. G. B. p. 17, pl. 10, f. 28, 29. 


There are two forms of this shell, so apparently distinct 


5oZ TROCHIDA. 


at the first glance, that we hesitated to regard them as 
belonging to the same species, yet so intimately connected, 
that when we examine a long series of specimens from 
various localities we cannot separate them with precision. 
The one is peculiarly oblique and depressed, with a very 
expanded outer lip, and the rest of its features modified to 
correspond with the general contour; the other is far more 
globular, and reminds us a little by its shape of the common 
Valvata (piscinalis ). 

The species is small, shining, translucent, smooth, except 
some minute and indistinct impressed spiral lines upon the 
base, and so thin that the internal nacre is visible through 
the external colouring, imparting to its horn-like hue a 
beautiful bronze-like lustre. For the most part two rather 
broad but undefined bands, of a deep flesh-like tint, encircle 
the body, the upper one of which is below, but not adjacent 
to, the suture; the lower, and less distinct one, is just 
above the basal circumference: occasionally they unite, so 
as merely to show a pale sub-sutural line upon the terminal 
volution. The shape, as we before remarked, is very 
variable, ranging from obliquely suborbicular to orbicular- 
conoid; the spire, however, is always a little raised, but 
its apex, though small, is blunt, and the apical volutions 
are rather depressed; the lateral outline is subrectilinear, 
or a little arched. There are five whorls, which rapidly 
enlarge ; the body, or final volution, is disproportionately 
ample, and, as well as the penult, is more or less ventricose ; 
their slope, in the more depressed variety, is very gentle, 
but becomes more considerable in the subconoid one: the 
sutural line is delicate. The base is more or less com- 
pressed, but is slightly convex. ‘The umbilicus is rather 
large and profound; it is not bounded by any angular 
ridge, but is moderately shelving. 


TROCHUS. ya) 


The aperture is nacreous, nearly circular, large, and 
more or less expanded ; in height it rather exceeds one- 
half of the entire length of the shell ; in breadth it occupies 
at least one-half the basal diameter. The outer lip is 
simple, acute, and recedes considerably in front ; the pillar- 
lip is narrow, thin, arched, and erect, only folding back 
very slightly at the umbilical cavity. The breadth of the 
shell, which is superior to its length, is about the sixth of 
an inch. 

The animal—for drawings of which we are indebted to 
Mr. Alder and Mr. Hancock —is of an orange colour, 
mingled with dusky. The muzzle appears to be very 
short, crenated, and deeply tinged on the summit with 
dusky. The tentacula are short in proportion to the 
body, rather stout, strongly ciliated. The head-lobes 
seem to be obsolete. The eye-peduncles are short. The 
neck-lappets are small, and even-edged. There are about 
five rather dusky lateral cirrhi on each side, three placed 
on the opercular region, and two anteriorly. The foot is 
rather large, oblong, obtuse in front and behind, tinged 
with dusky at the sides. The jaws are studded with 
closely-set papillae. Hach row of teeth on the lingual 
riband (according to the drawing by Mr. Alder) consists 
of a central denticle, which is rather broad anteriorly, 
strongly hooked, and wide-necked ; flanked on each side 
by six-rather obtusely and broadly hooked laterals, and a 
great number of narrow accessorials. 

This little shell ranges along the northern shores of 
Britain on both sides, and is a littoral species, occasionally 
descending into the Laminarian zone. It is usually found 
among sea-weeds and under stones near low-water mark. 
It ranges from Yorkshire and Northumberland (Alder) ; 


northwards on the eastern coast (Bean); occurring in 


534 TROCHIDA. 


Berwickshire (Johnston) ; Fifeshire (E. I.) ; Aberdeenshire 
(Macgillivray); very common among Laminaria in Orkney 
(Thomas); Zetland (M‘Andrew) ; Skye (E. F.); Oban, 
and elsewhere on the west coast of Scotland (Barlee) ; 
Arran, in the Clyde (Alder) ; north east coast of Ireland 
(W. Thompson). Its southernmost habitats are Dublin 
Bay (Warren) and Tenby (Lyons). Abroad its range 


corresponds to that of wadulatus. 


T. pusttius, Jeffreys. 


Minute, suborbicular, perfectly smooth, semi-transparent : um- 
bilicus narrow, longitudinally grooved at its commencement. 


Plate LX XIII. fig. 3, 4. 


Margarita pusilla, Jerrreys, Ann, Nat. Hist. vol. xx. p. 17. 


Although we entertain not the slightest suspicion of this 
minute shell being the fry of either Helicinus or undulatus, 
each of which, even in its earliest stage, exhibits spiral lines 
upon its base, it is nevertheless possible that this species 
may hereafter prove to be the young of some other northern 
shell not hitherto taken in our waters. 

It is excessively thin, semi-transparent, shining, sub- 
nacreous white, or amber-coloured, and of a somewhat 
globosely orbicular form, with the anterior end of the 
aperture projecting considerably below the basal level. 
The general surface is quite smooth,. yet, upon some of 
the larger specimens, there seem faint traces of longitudinal 
wrinkles. There are three convex whorls, that are neither 
depressed nor flattened, well-marked near the suture, and 
are much less shelving above than in Helicinus. The body, 
which is extremely ample in proportion, is yentricose, and 
broadly rounded at the circumference ; the penult volution 


t 


TROCHUS. Hoe 


is short, but convex; the apex is obtuse. ‘The base is 
not compressed, but moderately rounded ; the umbilicus is 
rather small, and is somewhat coarsely, though obscurely 
grooved in a longitudinal direction at its commencement. 
The aperture is very large, occupying about four-sevenths 
of the entire length, and at least half the basal diameter ; 
it is circular and almost continuous; the outer lip is acute 
and simple, the pillar-lip narrow, erect, but inclining a little 
towards the umbilicus. The specimens described from (the 
types) are only the twenty-fifth part of an inch in width, 
and about the thirty-fifth of an inch in length. They were 
taken by Mr. Jeffreys at Lerwick, the Shetland Isles, and 
Loch Carron. 

According to its discoverer it has a range of from ten to 
forty fathoms, and, besides the places mentioned, has been 
taken at Skye, at Falmouth, and Sandwich, and, by Mr. 
Clark, at Exmouth. Mr. Barlee informs us that he has 
taken it at Loch Carron, Loch Alsh, and at Oban. 


Note.—Margarita olivacea, Brown, Illust. Conch. G. B. p. 17, pl. 10, f. 30, 
31. “Thin olive-coloured, pellucid, smooth, subglobose ; body large, inflated ; 
spire small, short, with three depressed volutions, terminating in a moderately 
pointed apex ; aperture large, circular, standing out from the body; outer lip 
thin, continuous with the inner lip above, which is narrow, and a small circular 
umbilicus behind. Length two-tenths of an inch. Found at Greenock by Stewart 
Ker, Esq.” 

Neither ourselves nor any of our many correspondents have recognised this 
shell, which in shape is represented as not unlike a very large puséllus. Judging 
from the locality given it was probably a pleistocene fossil. 

M. aurea, Brown, Ill. Conch. G. B. p. 17, pl. 10, f. 23. “Strong, with four 
depressed, well divided volutions, covered with very strong spiral strie ; aperture 
round, which, with the pillar-lip, is tinged with a golden metallic hue ; outer lip 
strong ; inner lip smooth, very broadly reflected on the columella, and somewhat 
sharp at the base ; colour of a deep brownish-pink, with a golden metallic lustre. 
Length and breadth about a quarter of an inch. Found at Seaton, Northumber- 
land, by W. C. Trevelyan, Esq.” 

The figure looks like a foreign Turbo. We hope to examine the type before 
the conclusion of our work. 


536 TROCHID&. 


SPURIOUS. 


T. cinereus, Da Costa. 


Lister, Hist. Conch. pl. 633, f. 21. 


Trochus cinereus, DA Costa, Brit. Conch. p. 42, pl. 3, f. 9, 10.—Monr. Test. 
Brit. p. 289 ; Suppl. p. 119.—Downov. Brit. Shells, vol. v. pl. 
155, f. 2,—Marton and Rack. Trans. Linn. Soc. vol. viii. 
p- 152.—Turr. Conch. Diction. p. 188.—Dituw. Recent 
Shells, vol. ii. p. 782. 
»  excavatus, Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. ]50.—De.zs. Rec. 
Coquil. pl. 36, f. 4. 


A native of the West Indies ; introduced by Da Costa as found 
in several parts of Great Britain. 


Turso rucosus, Linneus. 


Knorr, Délices des Yeux, pt. 4, pl. 7, f. 1. 
Turbo rugosus, LINN. Syst. Nat. ed. 12, p. 1234.—Cuemn. Conch. Cab. vol. vy. 
p- 195, pl. 180, f. 1782 to 1787.—Lam. Anim. s. Vert. 
(ed. Desh.) vol. ix. p. 196.—Buarny. Faune Frangaise, Moll. 
p- 295, pl. 12, f. 1—Cosra, Test. Sicil. p. 101.—Mag. de 
Zool. (Guérin’s) series 1, Moll. pl. 39, animal.—Dersu. Encye. 
Méth. vol. iti. p. 1097.—Puinirri, Moll. Sicil. p. 178, and 
vol. ii. p. 151.—ReEvE, Conch. Icon. vol. iv. Turbo, pl. 6,f. 26. 
»  calecar, GMEL. Syst. Nat. p. 3592 (part only).—Monr. Test. Brit. Suppl. 
p. 137, pl. 29, f. 3.—Torr. Conch. Diction. p. 227. 
»  armatus, Dituw. Recent Shells, vol. ii. p. 829.—Brit. Marine Conch. 
p- 169. 
Delphinula calear, FLEMING, Brit. Anim. p. 312. 


A Mediterranean shell, of which the young is figured by Montagu, 
as taken by Mr. Laskey at Iona. 


Turso casTANEA, Gmelin. 


Turbo castanea, GMELIN, Syst. Nat. p. 3595, (from Chemn. Conch. Cab. vol. 
y. p. 211, pl. 152, f. 1813, 1814). — Brit. Marine Conch. 
p- 167. — Ditiw. Recent Shells, vol. ii. p. 836. — GEVvENS 

(ed. Bach.), p. 34, pl. 16, f. 150, 152. 
» mammillatus, Donov. Brit. Shells, vol. v. pl. 173.—MatTon and Rack. 
Trans. Linn. Soc. vol. viii. p. 166.—Monvr. Test. Brit. 
Suppl. p. 126.—Turt. Conch. Diction. p. 206.—FLEMminG, 


PHASIANELLA. Sat 


Brit. Animals, p. 299.—Coucu, Cornish Fauna, pt. 2, p. 
57.—Woop, Index Testae. pl. 31, f. 47. 
Turbo hippocastanum, LAM. Anim. s. Vert. (ed. Desh.) vol. ix. p. 198. 
»  crenulatus, GMELIN, Syst. Nat. p. 3595 (from Chem. vol. v. f. 1811, 1812). 
—KieEnER, Coquilles Vivant. Turbo, pl. 27, f. 1—Reerve, 
Conch. Icon. vol. iy. pl. 10, f. 42. 


A West Indian shell; introduced by Donovan as from the 
Scilly rocks. 


PHASIANELLA, Lamarck. 


Shell usually rather compact, not nacreous, smooth, 
ovato-conical, with a produced spire. Aperture oval, the 
lips not continuous on the body whorl. Operculum cal- 
careous, solid, tumid externally, subspiral on the inner 
surface. 

Animal having the head muzzle-shaped ; tentacula long, 
ciliated, eyes in distinct peduncles at their external bases ; 
no intertentacular lobes; neck with a strongly fimbriated 
lobe on each side; lateral superior expansion of the foot 
with three cirrhi on each side, the middle pair often very 
small; foot rounded in front, pointed behind; vent on the 
right side and shortly tubular; branchial plume long, 
single, partially free; tongue closely resembling that of 
Trochus. 

The only species of this beautiful genus which inhabits 
the British seas runs no risk of being confounded with the 
Trochi, though its animal is very nearly allied indeed to 
that group. 


VOL. II. Se 


538 TROCHIDA. 


P. putitus, Linneus. 


Plate LXIX. fig. 1, 2, 3, and (Animal) Plate D D, fig. 5. 


Lister, Hist. Conch. pl. 585, f. 44. 
Turbo pullus, Linn. Syst. Nat. ed. 12, p. 1233.— Putrenry, Hutchins, Hist. 
Dorset, p. 45.— Donov. Brit. Shells, vol. i. pl. 2, f. 2.—Monr. 
Test. Brit. vol. ii. p. 319.—MarTon and Rack. Trans, Linn. Soe. 
vol, viii. p. 162. — RackerTT, Dorset Catalog. p. 49, pl. 14, f. 1, 
3.— Turt. Conch. Diction. p. 201, f. 45, 46. — Brit. Marine 
Conch. p. 186.— Born, Testacea Mus. Ces. Vind. pl. 12, f£ 17, 
18.— Ditiw. Recent Shells, vol. ii. p. 872. — Lam. Anim. s. 
Vert. (ed. Desh.) vol. ix. p. 217. 
» pictus, Da CosTa, Brit. Conch. p. 1038, pl. 6, f. 1, 3. 
Phasianella pullus, SowERBY, Genera Shells, Phas. f. 4. — Forpes, Malac. Mo- 
nensis, p. 21. — Brown, Lllust. Conch. G. B. p. 9, pl. 10, 
f. 42.—Puivippi1, Moll. Sicil. vol. i. p. 187, and vol. ii. p. 
158.—KiEneER, Coquilles Vivantes, Phasian. pl. 5, f. 1.— 
REEVE, Conch. Systemat. pl. 223, f. 4. 
Cingula pulla, FLumrne, Brit. Animals, p. 308. 
Rissoa pullus, Macey. Moll. Aberdeenshire, p. 151. 


For brilliancy of colouring and diversity of painting, we 
have nothing comparable among our native shells, to this 
beautiful little Phasianella. It is ovate-acute, strong, 
almost opaque when full grown, highly polished, and ap- 
parently smooth: a lens of ordinary power, however, 
generally exhibits some longitudinal wrinkles, and the 
microscope reveals most dense and minutely undulated 
spiral striule likewise. Among the more ordinary tints 
with which its exterior is adorned, purplish-rose, crimson, 
red, chocolate-colour, and brown, may be specified ; these 
either form the ground itself (in which case the markings 
are pallid) or more frequently are profusely disseminated 
on a sallow or whitish surface. The patterns, which are 
of almost infinite variety, are composed of small spots and 
wavy linear streaks (more frequently angulated than not) 


that are sometimes mingled, sometimes uncombined; the 


PHASIANELLA. 539 


latter are for the most part arranged in obliquely longi- 
tudinal series, but oftentimes, owing to the regular thick- 
ening of the wavy lines at certain distances from the 
suture all round the shell, a few interrupted spiral bands 
are formed in addition. A not unfrequent style of paint- 
ing consists of broad wavy streaks of opaque white that 
radiate from the suture on a darker coloured ground. The 
space around the columella is almost invariably pale, but is 
generally traversed in a longitudinal direction by arcuated 
lines of colour. The whorls are four and a half in number, 
are separated by a simple suture, and rapidly enlarge from 
a small, but not very pointed, apex: those of the quickly 
attenuated spire, which altogether, when viewed from 
above (or dorsally), does not occupy more than three- 
eighths of the entire length, and only one-sixth when 
viewed ventrally, are somewhat rounded, and in propor- 
tion to their narrowness are tolerably high, The body, 
which is manifestly narrower posteriorly,—and this is more 
readily perceptible when the view is ventral,—is not regu- 
larly rounded, but both upper and lower slopes are merely 
convex, and the central portion is a little flattened. The 
base is imperforated, and is moderately long. The aper- 
ture, which is closed, when the animal is living, by a solid 
smooth and lustrous snow-white shelly operculum, is about 
half the total length of the shell, and four-sevenths of its 
basal diameter; it is pure white, devoid of all sculpture, 
and of a rounded oval shape, the length rather exceeding 
the width. The outer lip, which is simple, very acute, 
and arcuated, recedes in front: the pillar-lip is curved, 
broad, and appressed; its general inclination is rather 
perpendicular than oblique. Our largest example measures 
only three lines and a third in length, and two lines and a 


quarter in breadth. 


540 TROCHIDA. 


The animal is brilliantly coloured, tinted with shades of 
purple, yellow, and often of green. The muzzle is rather 
short, and has slightly crenated yellow-tinged lips. The 
upper part and the head are marked with purplish brown 
and white, the latter colour arranged in streaks. The 
tentacula are long and of a yellowish white colour; they 
are strongly ciliated. The eye-peduncles are white, or 
tinged with green. The neck lobes are prominent, some- 
what fan-shaped, and strongly fimbriated at their mar- 
gins. The sides of the foot are tinged or streaked with 
purplish brown; its sole is of a lanceolate form, rounded 
in front and pointed behind. The lateral expansions of 
the foot give origin to three cirrhi on each side. The 
middle pair are usually, though not always, much smaller 
than those in front and behind, so small sometimes as to 
cause the animal to appear as if it had only two cirrhi on 
each side. In an example taken in Milford Haven, 
figured in Plate DD, the middle pair of cirrhi were 
greatly developed, whilst in one which we observed at 
Dartmouth they were almost obsolete, and could not be 
seen when the creature was in motion. Mr. Alder and 
Mr. Spence Bate have observed it with only two lateral 
cirrhi on each side. When walking it vibrates its tenta- 
cula, and uses them as feelers, at the same time giving its 
shell a slight see-saw movement. 

This pretty shell is plentiful in most localities in the 
British Channel and Ivish Sea, though rare and local on the 
eastern and northern coasts of Britain. Margate (S. H.); 
Oban (Jeffreys). All round the coasts of Ireland (W. 
Thompson). It ranges to the Mediterranean, but is not 
present in seas north of our own. 


ADEORBIS, 541 


ADEORBIS, Szrartes Woop. 


Shell not nacreous, suborbicular, depressed, with few 
volutions, deeply umbilicated below. Peritreme entire, 
and nearly continuous, sinuated in its inner side, and 
slightly so externally. Operculum testaceous, multispiral. 

Animal unknown. 

We accept this genus as a good one although as yet 
the soft parts have not been observed. There can, how- 
ever, be little doubt that its true position is among the 
Trochide. The peculiarity of the form of the mouth 
strikingly indicates the affinity of the somewhat dissimilar 
shells composing it. The number of different genera to 
which existing species have been referred indicates how 
doubtful their position was held to be, and how necessary 
it was to constitute them into a group apart. It has near 
affinities with Delphinula and Scisswrella. 

These shells appear to frequent the laminarian and 
coralline zones. ‘They are all very small. The genus has 
members even so far as the Chinese seas. Mr. 5S. V. 
Wood enumerates five fossil species from the later British 
tertiaries. 


A. supcarinata, Montagu. 


Body whorl very large, encircled by four spiral ridges, crossed 
by arcuated lamellar striz. 


Plate LXVIII. fig. 6, 7, 8. 


Helix subcarinatus, Mont. Test. Brit. vol. ii. p. 438, pl. 7, f. 9. —Turr. Conch. 
Diction. p. 45. 
Trochus rugosus, BRowN, Mem. Werner. Soe. vol. ii. pt. 2, p. 520, pl. 24, f. 5. 
Cingula subcarinata, FLEMING, Brit. Animals, p. 305. 
Adcorbis subcarinata, SEARLES Woop, Annals Nat. H. vol. ix. (1842) p. 530; 
Crag Mollusca, p. 139, pl. xv. f. 8. 


542 TROCHIDA. 


Trochus subcarinatus, REcLUz, Révue Zoolog. Cuvier. 1843, p. 108.— HANL. 


Brit. Marine Conch. p. xxxix. (altered from Turbo s. 


p. 170.) — Brown, Ill. Conch. G. B. p. 19, pl. 11. 
f. 30, 31. 
Natica 2 subcarinata, Puivirrt, Moll. Sicil. vol. ii. p. 141, pl. 24, f. 13. 

It is to Scissurella and the smaller Delphinule, not to 
Trochus, that we must look for a sculpture analogous to 
the exquisite carving which distinguishes this beautiful 
shell from our other British testacea. 

The shell is entirely white, strong for its size, almost 
opaque, or only a little hyaline, and of a rather oblique 
and very depressed turbiniform contour. It is composed 
of from three and a half to four volutions, which increase 
rather rapidly in size, are flattened or concave above, and 
are moderately rounded below; the apex is scarcely at all 
elevated. Four strong nearly equidistant spiral ribs adorn 
the exterior of the body whorl, which, moreover, has a 
slight marginal thickening below the well-marked suture 
likewise. The two stronger of the belts are seated upon 
the superior surface, and the upper is continued along 
the higher portion of the smaller whorls. They are all 
more or less nodosely crenated, in the fresher exam- 
ples, by somewhat flexuously arcuated lamellar striz, 
that traverse the exterior in a somewhat obliquely 
longitudinal direction. These latter are numerous, but 
not crowded, that is to say, are not broader than their 
interstices ; are coarse upon the upper disk, and delicate 
upon the lower one, where they encircle the profound um- 
bilicus. The base is more or less flattened, and the per- 
foration is preceded toward the inner lip of the aperture by 
a broad shelving space that increases its apparent magni- 
tude. The aperture is not distinctly nacreous, and is quite 
smooth ; when viewed from below it appears of a rounded 


ovate figure; the inner lip, which recedes greatly, is a little 


SCISSURELLA. 543 


reflected ; the outer one is acute. The greatest diameter 
does not exceed the tenth of an inch. 

The operculum is shelly, circular, flat, closely and con- 
centrically multispiral, and presenting a punctured or 
frosted appearance on its surface. 

This pretty little shell is of southern and western range. 
Though by no means scarce in southern localities, it is 
rarely taken alive, and the animal has as yet been unob- 
served. It is found at Herm (S.H). Dartmouth in 
twelve fathoms (M‘Andrew and E.F). Fowey (Peach.) 
Exmouth, Sandwich, Swansea, Tenby (Jeffreys). Mr. 
M‘Andrew has dredged dead specimens in fifty fathoms of 
water, sixty-five miles from land in the southern part of 
the Irish seas. On both sides of Ireland (W. Thompson) ; 
Burra island, Arran (Barlee); Dublin bay, Cork (Jeffreys). 

It ranges to the Mediterranean, and is found fossil in 
both red and coralline crags. 


SCISSURELLA, A. D’OrBreny. 


Shell thin, subglobose, more or less depressed, with a 
large body whorl and small spire; surface variously orna- 
mented with striz and grooves; mouth rounded, outer lip 
incised or perforated in the line of a spiral marginated 
groove which winds round the body whorl; an operculum. 

Animal unknown. It appears, however, to have been 
met with by Sars,* and to hold the systematic position 
which we have assigned to it. 

The minute shells for which this genus was founded are 
very interesting on account of the close resemblance they 
bear to the fossil genus Pleurotomaria, indeed it seems 


* Zeitschrift fur Malakozoologie, 1847, p. 3. 


544 TROCHIDA. 


very difficult, if possible, to draw a line between the two 
groups. Until, however, the animal of Scisswrella be better 
known, and the Plewrotomaria, at present probably uniting 
creatures of different families, better investigated, it would 
be unsafe to merge the two genera in one. 


S. crispata, Fleming. 


Plate LXITI. fig. 6. 


Scissurella crispata, FL—EM. Mem. Wern. Soc. vol. vi. p. 385, pl. 6, f. 3; Brit. 
Anim. p. 866; Treatise Moll. Anim. pl. 13, f. 48.— Brit. 
Marine Conch. p. 152.—Browy, Illust. Conch. G. B. p. 62. 


A more extended knowledge of the influence of climate 
upon form, as well as sculpture, may greatly enlarge 
the synonymy of this minute and beautiful shell; for 
assuredly several of its congeners approach it most 
closely in general characters. It is thin, semitranspa- 
rent, of a pure and uniform white, and, in the individuals 
we possess (yet these probably are dead specimens), but 
little shining. The shape is obliquely suborbicular, and 
more produced at the base than at the spire; the lateral 
outlines of the upper disk are convex. ‘The sculpture, 
which is very elegant, and enriches alike the entire super- 
ficies, consists of a crowded decussation of delicate longi- 
tudinal and spiral laminar striz, both series being narrower 
than the intervals between them. The latter, which are 
chiefly visible in the interstices, and are rather the more 
minute, produce a crisp or slightly curly appearance 
where they intersect the others. A broad spiral groove, 
with raised edges, that terminates in a rather long fissure, 
winding along the bases of the smaller volutions, and encir- 
cling the body just above the middle, interrupts the graceful 
curves of the longitudinal strie, and produces a divarication 


SCISSURELLA. Hy: 9) 


of them, since those lying above it are more obliquely 
arcuated than those below it (which otherwise, both in 
strength and approximation, they exactly resemble), whilst 
those inclosed within it lean in an opposite direction to the 
two other series. The whorls, which are three in number, 
increase with some rapidity, and terminate in a flattened 
apex; although not much elevated, they are tolerably 
large, and being depressed above, but well rounded below, 
appear somewhat scalariform; the body-volution slopes 
with a gentle convexity from the well-marked suture. The 
base is not compressed, but rounded, and swells out near 
the lip to an extent almost equal to the rise of the spire ; 
the axis is perforated by a simple and wide-mouthed um- 
bilicus. The large aperture which is obliquely set, and of 
a depressed rounded-subquadrate form, bulges out consider- 
ably near the outer anterior corner ; it is broader than it is 
long ; the length occupies more than one half of the entire 
shell, the breadth is rather superior to one half the basal 
diameter. The outer lip, which greatly recedes in front, 
is simple, acute, and much arcuated, but its continuity is dis- 
turbed by the fissure, where it pouts out in an acuminated 
form, both above and below, becoming in the latter position 
peculiarly arcuated and effuse. The pillar-lip, which is 
more or less broad and flatly reflected, yet not appressed, 
is retuse behind; it is short, and is either straight or leans 
away from the outer lip. The breadth of most of the 
specimens hitherto obtained is not much more than the 
tenth of an inch, and this is nearly twice the length, which 
does not very much exceed two-thirds of a line. 

This beautiful but minute shell was discovered in 1809 
by the Rev. Dr. Fleming, who found it in sand from Noss 
Island, one of the Zetland group. Mr. Barlee has taken it at 
Kast Tarbert (Long Island), Loch Fyne, and on the north 


VOL, II. 4a 


546 TROCHIDA. 


and east sides of the Zetland isles, where he observes that 
it is “abundant in dredged shelly sand, and off stones in 
deep water on the Haaf ground.” Lieut. Thomas finds 
it abundantly in seven fathoms of water, at Sanda Sound 


in the Orkney Isles. 


547 


IANTHINID. 


Swarnson, who, whilst he has indulged overmuch in 
fanciful analogies and gone astray after phantom affinities, 
has frequently offered suggestions respecting the relation- 
ship of genera in Mollusks highly worthy of consideration, 
held that Scisswrella had distinct affinities with Lanthina. 
The presence of a true operculum in the former genus 
prevents our associating them in the same family, whilst 
the point of resemblance between them induces us to 
regard Janthina as the type of a group nearly related to 
the Trochide. Often, however, as the animal of this 
curious genus has been observed, and notwithstanding its 
investigation by the skilful hand and thoughtful head of 
Cuvier himself, its affinities have puzzled systematists, and 
are likely to do so for some time. The position which we 
assign to it in this work can be regarded only as an 
approximation towards its true place. Besides the con- 
nection with Trochus and its allies already indicated, the 
structure of the apex of the shell would seem to point out 
an alliance with Chemnitzia, as has been suggested to us 
by Mr. Jeffreys, whilst the forms and arrangement of the 
lingual teeth and conformation of the reproductive organs, 
indicate affinity with Scalaria, further borne out by the 
power common to the two genera of secreting a purple 


fluid. 


548 IANTHINIDA. 


IANTHINA. 


Shell ventricose, subglobular, thin, translucent, smooth 
or striated. Aperture more or less triangular, outer lip 
sub-emarginated, columella straight. No operculum. 

Animal with a large muzzle-shaped head, bearing a 
tentacle and a sustentacle on each side, but presenting no 
traces of eyes. Foot short, secreting a float composed of 
numbers of cartilaginous vesicles, on the under surface of 
which the egg-vesicles are borne. Sexes separate. Bran- 
chie of two plumes. Lingual band without axile teeth, 
but having two series of ]ateral uncini, slender and narrow, 
obtuse above and pointed below (Loven). 

These animals are pelagic, floating about on the surface 
of the ocean, often in myriads, and apparently always 
gregarious when in their natural haunts. The float at- 
tached to the foot was first (as well as the shell itself) 
noticed by Fabius Colonna in 1616: he designated it by 
the expressive and appropriate name of spuma cartilaginea. 
Cuvier observed that there was no anatomical connection 
between the two bodies. This was confirmed by Dr. 
Coates, who, in the fourth volume of the “ Journal of the 
Academy of Natural Sciences of Philadelphia,” gives an 
interesting account of his experiments on the float in the 
living animal. He found that it was entirely secreted by 
the foot, and that when a portion was removed, the injury 
was rapidly repaired. The egg-bags are attached to the 
under surface of the float, and, as well as that organ itself, 
appear to differ in form and arrangement in the different 
species. Dr. Coates remarks that the animal seems to 
occupy considerable time in the deposition of its eggs, the 
bags nearest to the extremity of the float being constantly 


IANTHINA, 549 


found empty, while the central ones contain young shells 
fully formed, and those towards the animal are filled with 
eggs. ‘¢ It appears probable,” writes that observer, ‘ that 
the young animals, when liberated from their chambers, 
ascend the float of the mother, and in this way gain access 
to the surface and construct the elements of their future 
support.” 


T. communis, Lamarck. 


Broader than long, angulated at the circumference ; aperture 
subtrapeziform ; outer lip meeting the pillar at right angles. 


Plate LXIX. fig. 6, 7. 


Felix ianthina, Linn. (not Brookes) Syst. Nat. ed. 12, p. 1246 (part only).— 
Brown, Mem. Werner. Soc. vol. ii. pt. ii. p. 525.—Turr. 
Conch. Diction. p. 58, f. 96.—Dillw. Recent Shells, vol. ii. p. 
938. 
Tanthine, Cuvier, Ann. du Mus. vol. xi. (1808), pl. 1, f. 1 ; Animal, f. 2 to 8 
(? all). 
Tanthina fragilis, Lam .(not Dekay,) Syst. Anim. s. Vert.—Monrrort, Conch. 
Syst. (1810), vol. ii. p. 214.—Sowexrsy, Genera Shells, 
Tanth. f. 1.—Swarnson, Zool. Illust. ser. 1, pl. 85.—Sow- 
ERBY, Manual Conch. f. 333.—D’OrpigNy, Mol. Canar. 
p- 83, Animal.—Broprrip, Penny Cyclop. vol. xii. p. 90, 
and fig. at p. 89, animal.— REEVE, Conch. Syst. pl. 205, f. 1. 
» communis, LAM. Anim. s. Vert. (ed. Desh.) vol. ix. p. 4. FLEMING, 
Brit. Anim. p, 324.—Brit. Mar. Conch. p. 151-—Brown, 
Illust. Conch. G. B. p. 24, pl. 8, f. 1, 2.—Crowcu, Introd. 
Lam. Conch. pl. 16, f. 3.—Lxsson, Voy, Coquille, p. 361, 
pl. 8, f. 1 (probably). 
Tanthine violette, var. BLAINV. Man. Malacol. pl. 37, bis, f. 1, a (not 1). 
Tanthina bicolor, Puiipe1, Moll. Sicil. vol. i. p. 164 ; vol. ii. p. 142.—Cosra, 
Test. Sicil. p. 112. 
Encycl. Méth. Vers, pl. 456, f. 1. 


In his earlier classification, Lamarck having termed the 
Helix ianthina of Linneus J. fragilis, without giving any de- 
scription, has appended a synonymy to it, that fairly enough 
agrees with that shell. In his “‘ Animaux sans Vertébres,” 


550 IANTHINID A. 


he has, however, changed the name of his type to J. com- 
munis, and mingled the synonymy of the present species 
with that of the West Indian shell (characteristically 
enough represented by Chemnitz, vol. v. f. 1577, 1578), 
which, from our study of the Linnean cabinet, we know 
to be the original ianthina of the Swedish systematist. 
We would suggest, then, the advisability of retaining the 
appellation of fragilis for that shell, and continuing that 
of communis to this far more abundant Mollusk. 

Although thin and fragile, this shell is comparatively 
strong for its genus. The dark violet or purple hue of its 
basal superficies is exchanged upon its upper surface for a 
much paler tint; but whilst the superior or narrower 
portion of each whorl is almost white, the lower part is 
more or less stained with the characteristic generic colour- 
ing: in oursmaller British examples a rather broad band of 
white encircles the axis. The shape is orbicular-conoid, and 
is horizontally compressed and generally but little rounded 
at the base. The surface is moderately glossed. Rather 
remote spiral lines, that are chiefly conspicuous upon the 
lower surface, and frequent irregular striz that follow the 
lines of growth, are more or less apparent upon the ex- 
terior ; besides these are some most minute and densely 
disposed spiral striule in the interstices of the stronger 
ones, but these are generally obsolete in the adult exam- 
ples. There are from four to four and a half volutions, 
that rapidly enlarge from a very small, obtuse, and 
distorted apex. The chief breadth of each whorl is at its 
bottom, and not towards the middle, as there is an almost 
continuous plano-convex shelve from suture to suture ; 
some few of our smaller examples, however, exhibit a 
slight shoulder, but we are inclined to regard this as 
exceptional. The proportion between the spire and the 


IANTHINA. Hoi 


body appears subject to much variation, the former being 
much more elevated in fine Mediterranean examples than 
in our more stunted native ones, in which latter the turns 
of the spire are mostly depressed and rather short. The 
suture, which is distinct but simple, and never canalicu- 
lated, is generally succeeded at a little distance, especially 
upon the last whorl, by an indentation that runs parallel 
to it, and which produces the effect of margination. The 
body, which is very ample, but whose expansion is in a 
transverse and not a longitudinal direction, is more rounded 
above than below, and is rather bluntly angulated at its 
circumference. The aperture is subtrapeziform, and, at 
the least, as wide as it is long; it occupies fully four- 
sevenths of the basal diameter, and ranges in length from 
about five-sevenths to only half of the entire length of the 
shell; the younger the shell, the greater, in general, is 
the proportion occupied by it. The medial sinuation of 
the outer lip, whose outline is more arcuated posteriorly 
than in front, and which meets the pillar at a right angle, 
and the body at an obtuse angle, is very gradual, but of 
considerable extent. The general inclination of the pillar, 
which is about half the height of the shell and a little 
wavy, is nearly straight; its reflection wholly or partially 
conceals any umbilical chink: in most native specimens 
it is dark violet. The individuals mentioned by Brown 
as taken in Ireland measured an inch by an inch and a 
quarter, and hence were equal in dimensions to the fine 
Mediterranean examples; those which we have ourselves 
met with, chiefly from the Welsh coast, had not attained 
to more than half this size. 

The animal is white, tinged often strongly with purple. 
The head is muzzle-shaped, thick, and rather lon 


g, with 


somewhat obtuse tentacles and cylindrical sustentacles. 


Nad IANTHINIDA, 


The mantle is deeply tinged with purple. The disk of 
the foot is rather small and is margined with purple. The 
egg-vesicles are closely set on the under side of the large 
float. Dr. Coates describes the float of this species as 
being convex, subearinate above, concave beneath, straight, 
and composed of large vesicles. The animal secretes its 
purple dye very rapidly. We painted some paper with it 
when fresh in 1837, and it still remains strongly coloured. 
Mr. Jeffreys writes: “On the 23rd of July, 1827, I 
picked up several hundreds of this shell on the sands in 
Oxwich bay, some of them having the animal and its dye 
sufficiently strong to stain a pocket-handkerchief.” He 
also remarks that the apex of the shell is like a Stylifer, and 
inflected like that of Odostomia. 

This is an oceanic shell, occurring chiefly on those parts 
of our coasts most exposed to the Atlantic. It has long 
ago been taken on the shores of Cornwall, and comes into 
the Bristol Channel, as Oxwich Bay, near Swansea, and 
Tenby (Jeffreys), Dawlish Warren (Mrs. R. Smith). A 
bicoloured variety has been taken by Miss Jeffreys at 
Bude in Cornwall. Mr. Couch remarks that the occur- 
rence of this shell on the Cornish coasts “is altogether 
casual, and depends on a combination of wind and weather. 
The usual season is from July to November, when the 
wind is rough or long between west and south; under 
which circumstances several floating animals, as Phy- 
salia, Velella, with the Janthine, are driven on our coast 
from the Atlantic, sometimes in considerable numbers.” 
Dr. Turton states that the fishermen’s wives call them 
Bullhorns. ‘ Drifted occasionally to the western, southern, 
and northern shores of Ireland” (W. Thompson). 


IANTHINA. 553 


I. patna, Harvey. 


Subglobose, almost smooth ; circumference rounded, not an- 
gulated. 


Plate LXIX., fig. 10, 11. 


Tanthina pallida, Harvey, MSS. cited by Thompson.—Brit. Marine Conch. 
p- 152. 

2 I, nitens, THompson (not Menké), Ann. Nat. Hist. vol. v. p. 96, pl. 2, f. 2. 

Tanthina patula, Puriiert, Moll. Sicil. vol. ii. p. 224, pl. 28, f. 14. 


This rare Janthina is perhaps equally entitled to be 
called patula, since both names appeared, as those of shells 
positively pronounced distinct from any known species, 
during the same year (1844); but as the shell had pre- 
viously been well figured in the ‘‘ Annals of Natural 
History,” as the J. pallida of Harvey’s MSS., although 
with ‘‘ ? nitens, Menké,” prefixed (the caution was neces- 
sary, as in the earlier works of that conchologist, the 
descriptions were so brief as to render recognition most 
uncertain), the balance seems in favour of the name 
bestowed by the British writers. 

The shape of this elegant shell is globose-subtrigonal, 
and the length and breadth are nearly equal. Its surface, 
which is but moderately glossy, and nearly smooth, merely 
presenting, in addition to its lines of increase, most deli- 
cately fine but densely disposed and universally diffused 
wavy spiral striule, is of a very pale violet, but assumes a 
deeper tone of colouring upon the columella, and towards 
the extreme anterior extremity. There are three and a 
half volutions, that, instead of continuously sloping from the 
suture—which is but very slightly oblique, profound, and 
even canaliculated eventually—are well rounded below, but 
depressed above. The spire is extremely short, and, when 


WOlee Tle 4B 


554 IANTHINIDA. 


viewed dorsally, appears to occupy only one-fifth or one- 
sixth of the entire length: its apex is flattened, or even 
sunken. The body-whorl is not angularly contracted at its 
circumference, but is ventricose and rounded ; yet the arch 
of its lateral outline is not regular, but displays a little 
flatness both above and below the middle of it: the base 
is not at all compressed, but distinctly rounded. The 
aperture, which is extremely ample, and patulous, occupies, 
for the most part, four-fifths of the length of the shell ; it 
is of a somewhat abbreviated ovate shape, but its regularity 
is affected by the roundness of the last whorl, and the 
comparative straightness of the pillar lip, the angle of 
whose union is always a very obtuse one. The general 
arcuation of the outer lip, which recedes but little at the 
base, is almost uninterruptedly semicircular; it rises, 
instead of declining, at its junction with the body, and 
unites with the pillar in a curved line, thus rendering the 
anterior extremity of the mouth rounded instead of angular. 
It is not angularly incised in the middle, but only sub- 
angulately sinuated ; this character is observable through 
the lines of growth, even where the lip (too commonly the 
case with all Zanthine) has been broken. The pillar lip, 
which is rather broad, and convexly reflected, is not oblique, 
but is often a little sinuous ; it does not quickly attenuate, 
but continues of nearly the same width down to its anterior 
extremity. Behind it lies a narrow subumbilical cavity, 
that is partially concealed by the curl of the upper portion 
of the pillar-lip. Foreign individuals often measure an 
inch in both directions, but the few individuals thrown 
upon our own coast are not quite so large. 

In our description we have been careful to particularize 
the points in which the species differs from the globosa of 


Swainson, its nearest congener; the narrow pillar-lip, and 


IANTHINA. aaa 


the attenuated front extremity of the latter are perhaps 
the most striking distinctions. 

This species was first described as distinct by Mr. W. 
Thompson, to whom it was communicated by Professor 
Harvey, who found it at Miltown Malbay, in Clare, 
where it had also been found by Mr. J. D. Humphreys, 
whose specimen is now in the Jeffreysian cabinet. 


I. exieua, Lamarck. 


With longitudinal lamellar wrinkles; spire rather elevated. 
Plate LXIX. fig. 8, 9. 


Tanthina exigua, Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 5.—Turron, Mag, 
Nat. H. vol. vii. p. 352,—Coucu, Cornish Fauna, pt. 2, p. 
54.—Brit. Marine Conch. p. 151.--Brown, Lust. Conch. 
G. B. p. 24, pl. 8, f. 16, 17.—Sowrrsy, Genera Shells, 
Ianth. f. 2, 3.—Swarnson, Zool. Illust. ser. 1, pl. 85.— 
Lesson, Voyage Coquille, p. 368, Moll. pl. 8, f, 4.—Dzsu. 
Encycl. Méth. Vers, vol. ii. pt. 2, p. 325.—ReExve, Conch. 
Systemat. pl. 205, f. 2, 3. 

Lanthine violette, Buainy. Man. Malacol. pl. 37, bis, f. 1 (not 1, a). 

»  naine, Quoy and Garmmarp. Voy. Astrolabe, Moll. pl. 29, f. 5, 6, 7, 

animal (probably). 

Encycl. Méth. Vers, pl. 456, f. 2. 

The densely disposed irregular lamellar wrinkles, that 
roughen the surface of this extremely fragile shell, render 
it easily distinguishable from its described congeners. It 
is of a somewhat conoidal subglobular shape, and is at- 
tenuated both above and below; the violet hue of its 
colouring has somewhat of a reddish cast, and becomes 
very pale, or almost white, upon the upper portion of the 
body, and very faint, oftentimes, beneath the simple but 
well defined suture of the superior volutions. Of the five 
whorls, those of the spire are rounded but sloping, are not 
particularly narrow, are moderately raised, and of gradual 


enlargement. The spire is rather elevated for the genus, 


556 IANTHINIDA. 


generally occupying, when viewed dorsally, about one- 
third of the length; it terminates in an acute and very 
small distorted apex. The body-whorl is subangulated in 
the line of its junction with the outer lip, and is usually, 
in the adult, distinguished at that circumference by a 
shallow, groove-like, spiral indentation. Beneath this the 
raised longitudinal wrinkles, which above it are narrower 
than their interstices, and run with an oblique arcuation, 
suddenly diverge with an opposite inclination, and become 
still more crowded than before. There are no spiral 
striule. The basal area is not compressed, but occupies a 
considerable portion of the length of the shell; its con- 
vexity is rather less than that of the upper surface. There 
is a small umbilicus, that is often but little apparent from 
the reflection of the pillar lip; which latter is elongated, 
nearly straight, and, generally, of a paler hue than the 
portion behind it. The aperture is longer than wide, and 
is of a somewhat broad semilunar form. The sinus of the 
outer lip is angular and profound. The length of our 
Irish specimens is half an inch, and the breadth four lines 
at the least. 

The figure which appears to represent this animal in the 
beautiful designs of Quoy and Gaimard, differs from the 
communis in exhibiting a foot much larger in proportion, 
slenderer tentacles, a shorter float, and more scattered egg- 
vesicles. Dr. Coates describes the float of ewiqua as being 
straight, narrow, flattened, and composed of small vesicles, 
bearing the egg-vesicles on the under surface, attached by 
a little line of pearly fibres. 

This species is much rarer than communis, and, like it, 
oceanic. Turton announced its occasional occurrence, along 
with the larger one, in the small coves about the Land’s 
End. Mr, Jeffreys has it in the Turtonian cabinet from 


IANTHINA. aE 


Ilfracombe, Mount Bay, and Land’s End; also from Kilkee, 
County Clare, in the collection of J. D. Humphreys. It 
was first announced, we believe, as Irish by Mr. R. J. 
Shuttleworth, who took it in Connemara. Dr, Farren 
has found it at Roundstone in Galway, and Mrs. Puxley 


in Bantry Bay (Jeffreys). 


END OF VOLUME II, 


LONDON: 
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