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Full text of "A manual of the Mollusca; a treatise on recent and fossil shells"

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HARVARD UNIVERSITY, 




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A lll.l;/ 

MANUAL OF THE MOLLUSfci: 

A TREATISE 

OF 

RECENT AND FOSSIL SHELLS. 



BY 



Br. S. p. JfOODWARD, A.L.S., 

I-ATE ASSISTANT-PALEONTOLOGIST IN- THE BRITISH . MUSEUM. 



WITH AN APPENDIX OF RECENT AND FOSSIL CONCHOLOOICAL 
DISCOVEEIES TO THE PEESENT TIME, 

By EALPH TATE, A.L.S., F.G.S. 



WITH NUMEROUS ILLUSTRATIONS, 

By a. N. WATEHHOUSE and J. W. LOWRY. 



^ LONDON : 
VIRTUE & CO., 26, lYY LANE. 

NEW YORK : VIRTUE AND YORSTON. 

1868. 



PREFACE. 



This Mannal, -vrliicli for six years occupied the Author's 
unceasing attention, was intended as a companion to Gen. 
Portlock's Geology ; and the desire to make it worthy of that 
association led to an amount of labour and expense which 
only a very extended circulation will repay. 

The plan and title were taken from the ' ' Manuel des 
Mollusques" of M. Sander Eang, incomparably the best 
work of its kind — for an acquaintance with which the author 
was indebted to his friend and master, "William Lonsdale — - 
the founder of the "Devonian System" in Geology. 

On the subject of classification and nomenclature the Author 
followed the advice and example of his former colleague in 
the Geological Society, the late Prof. Edwaed Poebes ; 
without whose approval he seldom added to, or deviated 
from, the practice and plan of the "History of British 
MoUusca." 

That be was right in taking this course, has been sanctioned 
by the highest authority in this country ; — since the same 
scheme has been employed by Prof. Owek in the Hunterian 
Lectures and Catalogue. It has also been adopted by Dr. E. 
Paleotje in the Madras Museum ; by the Rev. Prof. Hen-slow, 
in his Eeport to the British Association on the Eormation of 
Typical Collections ; and by Prof. Moeeis in his Catalogue of 
British Eo'ssils. 

It was the writer's desire, by abstaining from the intro- 

d 



IV PREFACE. 

duction of personal and peculiar views, and by adhering to 
whatever was well established and sanctioned by the best 
examples, to make the work suitable for the use of J^atural 
History Classes in the Universities. 

To facilitate reference, and meet the most general require- 
ments, the number of large groups and genera of shells has- 
been restricted as much as possible, and those less important 
or less understood, have been treated as " sub -genera." A 
great many- duplicate and unnecessary names have been men- 
tioned only, as will be seen by a glance at the Index, where 
they are printed in italics ; the writer's own wishes coincide 
with those of the distinguished botanist Sir J. E. SiiiTH, that 
*'the system should not be encumbered with such names;" 
but they have been admitted in deference to custom and 
general opinion.^' 

The rules of the British Association, intended to secure 
uniformity, have called into existence a few active opponents, 
seeking to distinguish themselves by the employment of pre- 
Linnean and MS. names, on the pretence of carrying out the 
*' law of priority " (p. 48). But this folly has reached its 
height, and will fall into contempt when it has lost its 
novelty, f 

The investigation of dates is the most disheartening work 
upon which the time of an author can be employed ; it is 
never safe to take them second-hand, and even reference to 
the original works is not always satisfactory. J 

Those portions of the work have been treated in most 
detail which throw light on particular branches of anatomy 
and physiology ; or on great natural history problems, such 

* All the blundering and bad spelling of English and Erench genus-makers will be 
found carefully recorded in the " Index Generum Malacozoonun," bj^ the accurate and 
\aiTLented Dr. Herrnaannsen, a work indispensable to every writer on Conchology. 

t One example will suffice. In an " Atheuseum " report, by Prof. E. Eorbes, the 
name " Lottia fulva" was misprinted " Jothia fulva;" but although immediately 
corrected, the erratum was formally installed as a " new genus," in the works of 
Gray, Philippi, Catlow, Adams, and other conchologists ! 

X The dates on the title pages of Journals and Transactions of Scientific Societies, 
are not usually dates of jncblication, but refer to the years /or ivhich they are issued to 
the subscribers. It is almost impossible afterwards to correct these false dates. 



PREFACE, -y 

as the value of species and genera, and the laws of geogra- 
phical and geological distribution. It is in these departments 
that the affinity of natural science to the highest kinds of 
human knowledge is most distinctly seen ; and in them the 
richest and noblest results are to be obtained. Por to the 
thoughtful and earnest inyestigator, nature ever discloses 
indications of harmony and order, and reflects the attributes 
of the Maker. 

The recreations of the young seldom fail to exercise a 
serious influence on after life ; and the utility of their pur- 
suits must greatly depend on the spirit in which they are 
followed. If wisely chosen and conscientiously prosecuted, 
they may help to form habits of exact observation ; they may 
train the eye and mind to seize upon characteristic facts, and 
to discern their real import ; to discriminate between the 
essential and the accidental, and to detect the relations of 
phenomena, however widely separated and apparently unlike. 
In this way ''la belle Science" (as Mr. Gaskoin calls Con- 
chology !) may acquire the influence of pursuits more usually 
resorted to for mental development and discipline. 

The wood-cuts have been principally executed by Miss 
A. 'N. AYaterhouse, of Marlborough House, from original 
drawings by the Author ; and although printed from stereo- 
types, they have the advantage of accurately representing 
what was wished to be shown. 

The engravings of Mr. "Wilson Lowry speak for themselves ; 
many of the figures are from the specimens in his cabinet ; 
and the interest he has taken in the work will be seen in the 
care with which the technical characters of the shells are 
expressed. 



The above paragraphs, forming the ' principal portion of the 
Preface to the first edition of this work, will suffice to show the 
objects which the late Author had in view. A few additional 



words are required in order to indicate in what respects this edi- 
tion differs from its predecessor. In the first edition the work 
consisted of three parts, in this it consists of two. In Part I. 
is comprised the general remarks on the structure, distribution, 
&c., of the Mollusca, while Part II. is devoted to the Sy- 
nopsis of the Grenera. The chapter on Tunicata has been 
omitted, since they are more nearly allied to the Poiyzoa 
than to the Mollusca proper, and since the treatment of the 
MoUuscoidan group would have made the work inconveniently 
bulky. It seemed preferable, therefore, to devote a future 
volume of the series to the Molluscoida (embracing both the 
Tunicata and the Poiyzoa) than to describe them in the 
present work. The book has been subjected to a complete 
revisal, and numerous alterations and additious have been 
made ; but the reviser has interfered as little as possible 
with the Author's original classification and systematic 

arrangement. 

A. E. 

Sejjt., 1866. 



CONTENTS. 

PAET I. 

CHAPTER I. 

PAGE 

On the Position of the Moleusga in the Animal Kingdom. 
— Cliaracters of the five primary groups, or sub -kingdoms :— 
Yertebrata—MoUusca—Anjiulosa—Coelenterata— Protozoa. 

Their antiquity 1~^ 

Glasses of Mollusga. — 1. Cephalopoda. — 2. Gasteropoda. — 

3, Pteropoda. — 4. Brachiopoda. — 5. Lamellibranchiata ... 3 — 7 

Habits and Economy of the Mollusga. — Sedentary tribes, their 
mode of attachment ; locomotive tribes, their means of pro- 
gression ; situations frequented by shell-fish. — Food : vege- 
table, infusorial, and animal feeders. — Use of shell-fish to 
other animals for food; use of shells for ornamental and 
other purposes ; prices of shells. — Longevity of molluscous 
animals ; tenacity of life ; fecundity ; oviposition 7 — 15 

Strugtuee and Physiology of the Mollusga. — Nervous 
system ; organs of sense. — Muscular system. — Digestive 
system ; lingual teeth ; secretions. — Circulating system ; 
aqiiiferous canals. — Eespiratory system. — The shell, its 
composition and structure; nacreous, fibrous, and porcel- 
lanous shells ; epidermis ; erosion of fresh- water shells. — 
Eormation and growth of the shell ; adult characters ; de- 
collated shells ; monstrosities ; colours ; the operculum ; 
homologies. — Temperature and hybernation. — Reproduction : 
of lost parts ; by gemmation ; vi-vdparous ; alternate ; ovipa- 
rous. — Development 15 — 45 

Classification. — Affinities; analogies; species; genera; families; 
the quinary system ; synonyms ; authorities ; types ; abbre- 
Yiations , 45 — 49 



Vlil CO]SrTEKTS. 

CHAPTER II. 

PAGE 

G-EO&IIAPHICAL Distribution. — Land pro^dnces ; marine pro- 
■\dnces. — Specific areas ; specific centres. — Generic areas ; 
snb-generic areas. — Bonndaries ; influence of climate. — Origin 
of provinces 50 

Marine Provinces. — Arctic genera; tropical genera; cosmopo- 
litan species 54 

I. Arctic Province „ 57 

II. Boreal Province : Norway, New England 60 

III. Celtic Province : Britain, Denmark ^1 

IV. Lnsitanian Pro^dnce : Portugal, Canaries, Madeira, 

Azores, Mediterranean, Black Sea 63 

V. Aralo-Caspian Province 68 

YI. West-African Province 69 

YII. South.- African Province 70 

YIII. Indo-Pacific Pro^dnce : Ped Sea, Persian Gulf .... 71 
IX. Australo-Zelandic Pro^dnce : New South. Wales, 

Tasmania, New Zealand - 74 

X. Japonic Pro^dnce 75 

XL Aleutian Province : Ochotsk, Sitka 76 

JProvinces on the IVestern Coast of A.mcrica 77 

XII. Californian Pro^dnce 78 

XIII. Panamic Province : Galapagos 79 

XIY. Peruvian Province 81 

XY. Magellanic Province : Falkland Islands 82 

XYI. Patagonian Pro^dnce 83 

XYII. Caribbean Pro"sdnce 84 

XYIII. Transatlantic Province ^ . . . 85 

Land Pegions. — Distribution of land and fresh- water shells ; 

gen.era of the Old and New World ; arctic regions 86 

1. Germanic Eegion : Siberia 89 

2. Liisitanian Eegion : Mediterranean Islands ; Madeira, 

Azores, Canaries, Cape de Yerdes, Ascension 91 

S. Helena, Tristan d' Acunha 96 

3. African Eegion 97 

4. Cape Eegion 97 

5. Yemen — Madagascar: Comoro Islands, Seychelles, 

Mauritius, Bourbon, Eodriguez 98 

6. Indian Eegion : Ceylon 99 

7. China and Japan 101 

8. Philippine Islands 101 

9. Java 102 

10. Borneo 102 



CONTENTS. IX 

PAGE 

1 1. Papiia and New Ireland 103 

12. Australian Eegion 103 

13. Sontli Australia and Tasmania lOi 

14. New Zealand 104 

15. Polynesian Eegion : Salomons, New Hebrides, New 

Caledonia, Feejees ; Friendly, Navigator's, Society 
Islands; Low Coral Islands; Sandwich Islands 104 

16. Canadian Regions : New England 106 

17. Atlantic States 107 

18. American Region 108 

19. Oregon and California 109 

20. Mexican Region 109 

21. Antilles ' 110 

22. Columbian Region : Gralapagos Ill 

23. Brazilian Eegion 112 

24. Peruvian Region 113 

25. Argentine Region -. 114 

26. Chilian Region : Juan Fernandez 114 

27. Patagonian Region : Fuegia, Falklands 115 



CHAPTER III. 

Distribution of the Mollusca in Time. — Geological Table ; 
distribution of Species in the Strata ; of Genera ; table of 
Characteristic genera ; table showing range of genera ; range 
of families ; numerical development in time. — Order of appear- 
ance of groups of shells ; order of succession. — Migration of 
species and diffusion of Genera in former times. — Method of 
Geological investigation. — Tertiary Age. — Secondary Age. — 
PalsBozoic Age. — Numerical estimate : living and foSsil 
species 117 



CHAPTER lY. 

On Collecting Shells. — Land-shells ; elevation on mountains. 
— Fresh- water shells.— Sea-shells, littoral species ; floating 
mollusca : the towing-net ; trawling ; kettle-nets ; deep-sea 
fishery ; trapping whelks ; dredging 13S 

Dredging papers, by M'Andrew and Barrett, Norway 144 

Dredging papers, by Forbes, vEgean 148 

Zones of depth : littoral ; laminarian ; coralline ; deep-sea coral 

zone 151 

Preservation of Molluscous animaJs for examination , . 153 



COlfTENTS. 

PART II. 

SYNOPSIS OF THE GENEEA. 



CHAPTER I. 

PAGE 

Class I. Cephalopoda. Order I. Dibranghiata 155 

Section A. Ogtopoda 158 

Earn, I. ArgonautidcB. — Argonauta = 161 

Fam. II. Octoj^odidce. — Octopus, Pinnoctopus, Eledone, Cir- 
roteutHs, Pidlonexis, Scseurgus, Bolitsena 163 

Section B. Degapoda 166 

Earn. III. Teuthidcs. — Loligo, Gonatus, SepioteutMs, 
Beloteuthis, G-eoteuthis, Leptoteuthis, Cranchia, Sepiola, 
Loligopsis, ClieiroteiitliiSj Histioteutliis, Onyclioteutliis, 
EnoploteuthiSj Ommastreplies, ThysanoteutHs, Loliolus, 
Plesioteuthis, Dosidicus 167 

Earn. IV. Belemnitidce. — Belerrmites, Belemnitella, Xiph.o- 
teiitliiSj Acantlioteutliis, Belenmoteuthis, Conoteutliis .... 173 

Earn. Y. Sepiadce. — Sepia, Spiiailirostra, Beloptera, Belem- 
nosis, HeHcerus 176 

Earn. YI. Sjnndidce. — Spirtila 17? 

Order II. Tetrabranghiata 178 

Earn. I. Nautilidce. — Nautilus, Lituites, Troclioceras, Cly- 
menia 185 

Earn. II. OrtlioceratidcB.- — Orttoceras, Gomplioceras, Onco- 
ceras, Pirragmoceras, Cyrtoceras, Gr}n:oceras, Tlioracoceras, 
IsTothoceras 190 

Earn. III. Ammo7iitidcB. — Goniatites, Phatdoceras, Bactrites, 
Ceratites, Ammonites, Crioceras, Toxoceras, Ancyloceras, 
Scaphites, Helicoceras, Turrilites, Hamites, Ptychoceras, 
Baculites 195 

CHAPTER II. 

Class II. Gasteropoda , 202 

Order I. Prosobranghiata 209 

Section A. Siphonostomata 209 

Eam. I. Stromlidcc. — Strombus, Pteroceras, RosteUaria, 
Seraplis 210 



CONTEl^fTS. XI 

PAGE 
Fam. II. Mnricidce. — Murex, Typhis, Pisania, Eanella, Triton, 

Fasciolaria, Turbinella, Cancellaria, Dibaplius, Tricho- 

tropis, Pyrula, Fusus 212 

Fam. III. Buccinidce. — Buccinum, Pseudoliva, Anolax, 
Halia, Terebra, Eburna, Nassa, Phos, Pingicula ?, Purpura, 
Purpurina, Pbizocliilus, Monoceros, Pedicularia, Pdciniila, 
Planaxis, Magilus, Cassis, Oniscia, Cassidaria, Pacliyba- 
tkron, Dolium, Harpa, ColumbeUa, Oliva, AnciUaria .... 218 

Fam. IV. Conidce-. — Conus, Plexu-otoma, Citbara 228 

Fam. V. Volutidce. — Yoluta, Cymba, Mitra, Yolvaria, ]\Iar- 
ginella 229 

Fam. YI. Cyprceidce. — Cypreea, Erato, Ovulum 232 

Section B. Holostomata 234 

Fam. I. Naticidce. — Natica, Deshayesia, Naticella, Sigaretus, 

Lam.ellaria, Narica, Yelutina, Cryptocella 235 

Fam. II. Fyramidellidce. — Pyramidella, Odostomia, Cbem- 

nitzia, EuHma, Monoptigma, Aclis, Styloptygma, Myonia, 

Leucotina, Stilifer, Loxonema, Macrocbeilus 238 

Fam. III. Cerithiada. — Ceritbium, Potamides, Nerintea, 

Fastigiella, Aporrbais, Strutbiolaria 242 

Fam. lY. Melaniadce. — Melania, Paludomus, Melanopsis . . 246 
Fam. Y. Turritellidce. — Turritella, Caecum, Yermetus, Sili- 

quaria, Sealaria 248 

Fam. YI. Littoriiiidce. — Littorina, Solarium, Pborus, Lacuna, 

Litiopa, Eissoa, Skenea, Truncatella ?, Litboglypbus .... 250 
Fam. YII. Faludinidce. — Paludina, AmpuUaria, Ampbibola, 

Yalvata 257 

Fam. YIII. Neritidce. — Nerita, Pileolus, Neritina, Navicella 260 
Fam. IX. TurbinidcB. — Turbo, Phasianella, Imperator, Tro- 

clius, Eotella, Monodonta, Delpbinula, Adeorbi&, Euom- 

phalus, Stomatella, Broderipia 263 

Fam. X. Saliotis. — Haliotis, Stomatia, Teinotis, Scissurella, 

Pleurotomaria, Murcbisonia, Trocbotoma, Cirrus, lantldiia 268 

Fam. XI. FisstcrelUdce. — Fissurella, Puncturella, Eimula, 
Emarginula, Parmopborus , 272 

Fam. XII. Calyptrceidce. — Calyptrgea, Crepidula, Pileopsis, 

Hipponyx 275 

Fam. XIII. FatelUdcB. — Patella, Acmaja, Gadinia, Sipbonaria 278 

Fam. XIY. Fentaliadce. — Dentalium 282 

Fam. XY. CJiitonidce. —Chiiou 282 



Xll CO]SrTE]N"Tt!. 

PAGE 
C.AJSlI. G-ASTEKOPODA. OuDER 11. PuLMONirEKA 285 

Section A. Inopehgulata 285 

!Fam. I. Helicida. — Helix, Yitrina, Succinea, Bulimus, 
Acliatina, Pupa, Gylindrella, Balea, Tornatellina, Paxillus, 

Clausilia ' 288 

Fam. II. Limacidce. — Limax, Anadenus, Incilaria, Arion, 
Parmacella, Janella, Aneitea, Parmarion, Triboniopliorus, 

Viquesnelia, TestaceUa 295 

Fam. III. OncidiadcB. — Oncidium, Yaginulus 299 

Earn. lY. Limnceidce. — Limnaaa, Chilinia, Ptysa, Ancylus, 

Planorbis 300 

Fam. Y. AuricuUdce. — Atiricula, Conovulus, CarycHum 
(Siphonaria) 303 

SscTioN B. Opergulata 305 

Fam. YI. CyclcstomidcB, — Cyclostoma, Ferussina ?, Cyclo- 

pliorus, Pupina, Helicina, Stoastoma 306 

Fam. YII. AeicuUdcs. — Acictda, G-eomelania 310 

Order III. Opistho-branchiata 311 

Section A. Tegti-eranghiata 312 

Fam. I. Tornatellidce. — Tornatella, Cinulia, PingiciUa, Glo- 
l)iconclia, Yarigera, Tylostoma, Pterodonta ?, Tornatina ?. . 312 

Fam. II. BuUidce. — BuUa, Acera, Cylichna, Kleinella?, 
AmpMsplij-ra, Bucciniilus, Aplustrum, Scaphander, PM- 
line, Doridium, G-astropteron, Pliysema 315 

Fam. III. Aplysiadcs, — Aplysia, DolabeUa, Styloclieilus, 
Dolabrifera, Siplionopyge, Notarclius, Icarus, Lobiger .... 320 

Fam. lY. Tleurohranchida. — Pleurobranclius, Postero- 
brancliaea, Euncina, Neda, Susaria, Umbrella, Tylodina . . 322 

Fam. Y. FhilUdiad(S. — Phyllidia, Fryeria, Hypobrancliiaea, 
Diphyllidia 324 

Section B. Nudibranghiata 325 

Fam. YI. Doridce. — Doris, Heptabranclius, Hexabranclius, 
Atagema, Actiuocyclus, Chromodoris, Asteronotus, Glos- 
sodoris, Goniodoris, Triopa, ^girus, Thecacera, Polj^cera, 
Idalia, Ancula, Ceratosoma, Trevelyana, Crimora, Pelagella, 

Gymnodoris, Acantliodoris, Casella, Brach-ycMamis 328 

Fam. YII. TritoniadcB. — Tritonia, ScyllEea, Tethys, Bornella, 
Dendronotus, Doto, GelHna, Meliboea, Lomanotus 332 

Fam. YIII. JEolidce. — JEolis, Glaucus, Fiona, Embletonia, 
Calma, Favorinus, Galvina, Cutlionia, Filurus, Proctonotus, 
Antiopa, Hermasa, Alderia, Cbiorsera 335 



C0E'TE]srTS. xiii 

PAGE 

Fam. IX. FhyllirhoiclcB. — Phyllirlioe 338 

Fam. X. Elysiaclce. — Elysia, Acteonia, Cenia, Limapontia, 
Khodope 339 

Order IV. Nugleobrakghiata 3-i0 

Fam. I. FiroUclcB. — Firola, Carinaria, Oardiapoda 342 

Fam. II. AUcmtklce. Atlanta, Porcellia, BeUeroplioii, Cjx- 
tolites, Macl"area 343 

Class III. Pteropoda 346 

Section A. Thegosomata 348 

Fam. I. SijaleidcB. — Hyalea, Cleodora, CuTieria, Theca, 

Pterotheca, Conularia, Eurybia, Cymbulia, Tiedemannia . . 348 

Fam. II. LimaciniclcB. — Limacina, SiDixialis, Cheletropis, Mac- 

gilHyrajda 351 

Section B. Gymnosomata 353 

Fam. III. CUidce. — Clio, Pneumodermon, Pelagia, Cymo- 
docea 353 

CHAPTER III. 

Class IV. Braghiopoda , 354 

Fam. I. TereiratuUdcB. — Terebratula, Terebratella, Argiope, 

Thecidium, Stringocepbaliis 363 

Fam. II. SinriferidcB. — Spirifera, Atliyris, Petzia, Uncites. . 371 
Fam. III. Rhynchonellidce. — Illiyncb.onella, Pentameriis, 
Atrypa 375 

Fam. IV. OrthidcB. — OrtMs, Stropbomena, Da^ddsonia, Cal- 
ceola 379 

Fam. V. FroductidcB. — Productus, Stropbalosia, Cbonetes . . 383 

Fam. VI. CraniadcB, — Crania 386 

Fam. VII. DiscinidcB. — Discina, Siphonotreta 388 

Fam. VIII. Lingididce. — Lingnla, Obolns , 390 

CHAPTER IV. 

Class V. Conchipera 393 

Section A. Asiphonida 406 

Fam. I. OstreidcB. — Ostrea, Anomia, Placuna, Pecten, Lima, 
Spondylns, Plicatula 407 

Fam. II. Avimlidce. — Avicnla, Posidonomya, Avictdo -pecten, 
(^erviUia, Perna, Inoceramns, Pinna 415 

Fam. III. Jf^^;^7^■^i^.— Mytilus, MyaHna, Modiola, Hippomya, 
Dreissena 420 



XlV CONTEN'TS. 

I'AGfE 
Fam. lY. Arcadce. — Area, Cuculleea, Pectunculus, Limopsis, 

Nucula, Isoarca, Leda, Solenella, Solemya -. 424 

Fam. Y. Trigoniadce. — Trigonia, Myophoria, Axinus, Cur- 

tonotus, Pseudaxinus, Lyrodesma 430 

Fam. YI. TJ^iionidce. — Unio, Castalia, Anodon, Iridina, 

Mycetopus, ^theria, Miilleria 435 

Section B. Siphonida : Integro-palliaKa 436 

Fam. YII, CkamidcB. — Chama, Diceras, Eeqiiienia 437 

Fam. YIIl. HixoiyuritidcB. — Hippurites, Eadiolites, Capri 

:aeJLla, Ca'prina, Caprotina 440 

Fam. IX. Tridacnidcs. — Tridacna 451 

Fam. X. Cardiadce. — Cardium, Conocardium 453 

Fam.. XI. LucinidcB. — Lucina, Corbis, Tancredia, Diplo- 
donta, Ungtilina, KeUia, Montacuta, Lepton, Galeomma 455 

Fam. XII. CycladidcB. — Cyclas, Cjorena, Cyrenoides 461 

Fam. XIII. CyprinidcB. — Cyprina, Cii'ce, Astarte, Gouldia, 
Crassatella, Isocardia, Cypricardia, Plein-opliorus, Cardilia, 
]\Iegalodon, Pachydomus, Pachyrisma. Opis, Cardinia. 
Myoconcha, Cardita, Yerticordia 463 

Section C. Siphonida ; Sinu-pallialia 472 

Fam. XIY. Veneridcg. — Yenus, Cytlierea, Meroe, Trigona, 

Artemis, Lucinopsis, Tapes, Yenerupis, Petricola, Glau- 

comya 472 

Fam. XY. Ilactridce. — Mactra, HarveUa, Gnathodon, Lu- 

traria, AnatineUa 477 

Fam. XArr. Tellinid(B. — TeUina, Gastrana, Capsula, Quen- 

stedtia, Psammobia, Sanguinolaria, Semele, Mesodesma, 

Ervilia, Donax, Galatea 479 

Fam. XYII. Solenid<s. — Solen, Cultellus, Solecm-tus 486 

Fam. XYIII. Myacidce.—lslY^, Corbula, NeEera, Tbetis, 

Panopsea, Glycimeris 489 

Fam. XIX. Anatinidoi. — Anatina, Eibeiria, Thracia, Pbola- 

domya, Myacites, Ceromya, Cardiom.orplia, Edmondia, 

Lyonsia, Pandora, Myadora, Myocbama, Cbamostrea .... 494 
Fam. XX. GastroclKsnidce. — Gastrocbaina, Saxicava, Clara- 

gella, Aspergillum, Humpbreyia 500 

Fam. XXI. Fholalidce. — Pbolas, Pboladidea, Xylopbaga, 

Teredo 503 

Index 508 



A 

MANUAL OF THE MOLLUSCA. 



PART I. 



•^ CHAPTEE I. 

/ON THE POSITION OF THE MOLLUSCA IN THE ANIMAL KINGDOM. 

All known animals are constructed upon five different types, 
and constitute as many natural divisions or sub -kingdoms. 

1. The highest of these groups is separated from the next 
below it by a sharp line of distinction. In it the main mass of 
the nervous system is placed on the dorsal side of the body, and is 
in no instance pierced by the alimentary canal. It is separated 
from the alimentary canal by a partition, which in most cases 
is bony, and divided into separate parts, known as vertebrae ; 
while in a few it is cartilaginous, and not divided into distinct 
parts. Yertebrae are a common feature amongst the Vertebrata, 
as this sub-kingdom is called ; but they do not form an essential 
characteristic, as the name might seem to imply. Distinct 
organs are devoted to the functions of respiration and circu- 
lation ; the sexes are generally distinct ; each individual is 
generally developed from a single egg. Blood red. 

2. In the second sub-kingdom, or MoUusca, which is well 
exemplified by the common garden snail, the nautilus, and the 
oyster, the soft parts are in most cases protected by an external 
shell, which is harder than the bones of the vertebrates, and the 
covering of the crab and lobster. It consists almost entirely of 
carbonate of lime, while the bones of the vertebrates contain a 
large proportion of phosphate of lime. The shells of many of 
the Brachiopoda, such as Lingula^ and of a few of the Pteropoda, 



2 MANFAL OF THE MOLLTJSCA. 

such as Conularia, are ricli in the phosphate of lime. The 
digestive cavity is completely separated from, the walls of the 
body. The nervous system consists of three pairs of ganglia, 
except in the Brachiopoda, and these nervous centres are very 
much scattered. Hence Professor Owen has proposed the term 
Heterogangliata for the great group of Mollusca. The end of 
the alimentary canal nearest the mouth is surrounded by the 
ganglia which supply the foot and head. 

3. The various tribes of insects, spiders, crabs, starfishes, 
echinoderms, entozoa, and worms, have no internal skeleton ; 
but to compensate for it, their outer integument is suflBciently 
hard to serve at once as a support, a covering, and a defence 
for the soft parts. This external armature, like the bodies and 
limbs which it covers, is divided into segments or joints, which 
well distinguishes the members of this group from the others. 
The propriety of arranging worms with insects will be seen, if 
it be remembered that even the butterfly and bee commence 
existence in a very worm-like form. This division of jointed 
animals bears the name of the Annulosa. The nervous system 
consists of ganglia arranged in pairs in the middle line of the 
body. From this equal lateral development of the nervous 
centres Professor Owen calls the group Homogangliata. The 
nervous system is traversed by the alimentary canal. The 
radiated animals form a part of this sub-kingdom. 

4. The next sub-kingdom comprises most of the polypes, 
such as sea-anemones, the fresh-water hydra, and oorals, in 
which the general cavity of the body communicates freely with 
that of the digestive apparatus, on which account they are 
called Coelenterata. The soft parts forming the body wall are 
composed of two distinct membranes ; there is no heart ; no 
apparent special respiratory organ ; and in most cases very 
slight traces of a nervous system. 

5. All the animals not combined in the above groups, such as 
the sponges, the foraminifera, and a large proportion of the 
microscopic animalcules, form the last sub-kingdom, named 
Protozoa. They are characterised by a general abse!iice of any 
special organ. 

There seems to be a much closer relationship between the 
molluscan and the protozoic sub -kingdoms than between the 
moUuscan and any of the others. It is always easier to pass 
from the highest part of a sub-kingdom downwards in the scale 
of nature than to pass upwards. Thus we can step from one 
form to another without meeting with any marked distinction 
from the Cephalopods to the Brachiopods, and from them to the 



CLASSES OP THE MOLLUSCA. 3 

Protozoa. In the same way we can pass from the liigliest of the 
Aunulosa to the Protozoa. But we cannot find any continuous 
succession of adult forms which will connect the Annulosa with 
the Mollusca, or the MoUusca with the Yertebrata. 

Much use is made of the terms high and low in speaking of 
animals ; and it is important to bear in mind that they are by 
no means intended to imply that there is any difference in the 
degree of perfection, or that one animal is less fitted to subserve 
the purposes of life than another. By an animal of a low 
organisation is simply meant one in which all the functions 
of life are carried on by means of a few organs. The greater 
the number of organs that are set apart to perform special 
functions the higher is the animal said to be. 

The evidence afforded by geological researches seems to show 
that the leading types of animal structure have existed from a 
comparatively early period in the history of the globe ; and that 
all forms which have left any indications of their existence 
belong to one or other of these types. The oldest fossils known 
at the present time belong to the Protozoa ; but next to them 
come the Mollusca. 

By adding to the living population of the world, those forms 
which peopled it in times long past, we may arrive at some 
dim conception of the great scheme of the animal kingdom. 
And if at present we see not the limits of the temple of nature, 
nor fully comprehend its design, — at least we can feel sure that 
there is a boundary to this present order of things ; and that 
there has been a plan, such as we, from our mental constitu- 
tion, are able to appreciate, and to study with ever-increasing 
admiration. 

Classes of the Mollusca. 

This sub-kingdom consists of two gioat groups, viz., the 
mollusca proper and the moHuscoida. The mollusca are animals 
with soft bodies, enveloped in a muscular skin, and usually 
protected by a univalve or bivalve shell. That part of their 
integument which contains the viscera and secretes the shell, is 
termed the mantle ; in the univalves it takes the form of a sac, 
with an opening in front, from which the head and locomotive 
organs project : in the bivalves it is divided into two lobes. 

The univalve mollusca are encephalous, or fui'nished with a 
distinct head ; they have eyes and tentacula, and the mouth is 
armed either with jaws or with tooth straps.** Ouvier has 

* One of the drawbacks to the study of mollusca is the prevalence of such terms as 
jaws, anus, feet, &c. The reader must not suppose that the parts so designated are 

b2 



MANUAL OP THE MOLLTJSCA. 



divided them into tkree classes, founded on the modifications of 
their feet, or principal locomotive organs. 

1. The cuttle-fishes constitute the first class, and are termed 




Fig. 1.* Oral aspect of a Cephalopod. 

Cephalopoda^^ because their feet, or more properly arms, are 
60 attached to the head as to form a circle round the mouth. 
2. In the Gasteropoda,l or snails, the under side of the body 





Fig. 2. A Gasteropod.§ 



Fig. 3. APteropod.l 



forms a single muscular foot, on which the animals creep or 
glide. 

homologous in the vertebrata and in the moUusca. When applied to the latter, the 
terms are vague and indefinite in meaning. 

* Fig. 1. Loligo vulgaris, Lam. ^. From a specimen taken off Tenby, by J. S. 
Bowerbank, Esq. The mandibles are seen in the centre, surrounded by the circular 
Up, the buccal membrane (with two rows of small cups on its lobes), the eight sessile 
arms, and the long pedunculated tentacles {t), with their enlarged extremities or cluba 
(e). The dorsal arms are lettered d, the funnel/. 

t From cephale, the head, and joo^a, feet. See the frontispiece and pi. I. 

X Gaster, the under side of the body. 

§ Fig. 2. Helix desertorum, Forskal. From a hving specimen in the British Museum, 
March, 1850. 

D Fig. 3. Hyalcea tridentata, Lam., from Quoy and Gaimard. 



CLASSES OF THE MOLLUSCA. 



3. Tlie Pteropoda * inhabit the sea only, and swim with a pair 
of fins, extending outwards from the sides of the head. 

The other mollusca are acephalous, or destitute of any distinct 
head ; they are all aquatic, and most of them are attached, or 
have no means of moving from place to place. They are divided 
into three classes, characterised by modifications in their breath- 
ing-organ and shell. 

4. The Brachiopoda f are bivalves, having one shell placed on 
the back of the animal, and the other in front ; they take their 
name from two long ciliated arms, developed from the sides of 




Figs. 4, 5, 6. Brachiopoda.t 

the mouth, with which they create currents that bring theia 
food. These arms were formerly supposed to take the place of 
the feet in the previously-mentioned classes. They are, how- 
ever, essentially breathing organs, and consequently the term 
Brachionohranchia (arm-breathers) has been proposed for the 
erroneous one of Brachiopoda (arm-footed). 

5. The Lamellihranchiata, § or ordinary bivalves (like the 
oyster), breathe by two pairs of gills, in the form of flat mem- 
branous plates, attached to the mantle ; one valve is applied to 
the right, the other to the left side of the body. This class is 
sometimes called Conchifera. 

The Tunicata have no shell, but are protected by an elastic, 
gelatinous tunic, with two orifices ; the breathing organ takes 
the form of an inner tunic, or of a riband stretched across the 
internal cavity. These together with the Polyzoa, and perhaps 

* Pteron, a wing. 

t Brachion, an arm. 

t Fig. 4. (3.) Bhynchonella psittacea, Chem. sp., dorsal valve, vrith the animal 
(after Owen). 5, 6, Terebratula australis, Quoy. From specimens collected by Mr. 
J ukes. (2.) Ideal side view of both valves (/, the cardinal muscles, by which the valves 
are opened). (1.) Dorsal valve. These woodcuts have been kindly lent by Mr. J. E. 
Gray. 

§ £jimeilibranchiata, plate-gilled. 



b MANUAL OF THE MOLLrSCA. 

the Brachiopoda, form the sub-class of Molluscoida. In the 
first edition the Tu7iicata were described in detail, but they are 
omitted in this for reasons stated in the preface. 

Eiye of these modifications of the molluscan type of organi- 
sation were known to Linnseus, who referred the animals of all 
his genera of shell-fish to one or other of them ; * but unfortu- 
nately he did not himself adopt the truth which he was the 
first to see ; and here, as in his botany, employed an artificial, 
in preference to a natural method. 

The systematic arrangement of natural objects ought not, 
however, to be guided by convenience, nor " framed merely for 
the purposes of easy remembrance and communication." The 





Try-' 



rig. 7. A Bivalve.t Fig. 8. A Tunicary.t 

true method must be suggested by the objects themselves, by 
their qualities and relations ; — it may not be easy to learn, — it 
may require perpetual modification and adjustment, — but inas- 
much as it represents the existing state of knowledge it will aid 

* The Linnsean types were— f^'epia. Limax, Clio, Anomia, Ascidia. Terebratula 
was included with Anomia, its organisation being unknown. 

t Mya truncata, L. h From Forbes and Hanley. 

t Ascidia mentula, Miill. Ideal representation ; from a specimen dredged by Mr. 
Bowerbank, off Tenby. 



HABITS AlfD ECONOMY OP THE MOLLUSCA. 7 

in the understanding of the subject, -whereas a "dead and 
arbitrary arrangement " is a perpetual bar to advancement, 
•' containing in itself no principle of progression." [Coleridge.) 

Habits and Economy or the Molltjsca. 

Every living creature has a history of its own ; each has 
characteristics by which it may be known from its relatives ; 
each has its own territory, its appropriate food, and its duties 
to perform in the economy of nature. Our present purpose, 
however, is to point out those circumstances, and trace the 
progress of those changes which are not peculiar to individuals 
or to species, but have a wider application, and form the history 
of a great class. 

In their infancy the molluscous animals are more alike, both 
in appearance and habits, than in after life ; and the fry of the 
aquatic races are almost as different from their parents as the 
caterpillar from the butterfly. The analogy, however, is reversed 
in one respect ; for whereas the adult shell-fish are often seden- 
tary, or ambulatory, the young are all swimmers ; so that by 
means of their fins and the ocean-currents, they travel to long 
distances, and thus diffuse their race as far as a suitable climate 
and conditions are found. Myriads of these little voyagers 
drift from the shores into the ope a sea and there perish ; their 
tiny and fragile shells become part of a deposit constantly 
accumulating, even in the deepest parts of the sea. 

Some of these little creatures shelter themselves beneath the 
shell of their parent for a time, and many can spin silken 
threads with which to moor themselves, and avoid being drifted 
away. They all have a protecting shell, and even the young 
bivalves have eyes at this period of their lives, to aid them in 
choosing an appropriate locality. 

After a few days, or even less, of this sportive existence, the 
sedentary tribes settle in the place they intend to occupy during 
the remainder of their lives. The tunicary cements itself to 
rock or sea-weed ; the ship-worm adheres to timber, and the 
pholas and Uthodomus to limestone rocks, in which they soon 
excavate a chamber which renders their first means of anchorage 
unnecessary. The mya and razor-fish burrow in sand or mud ; 
the mussel and pinna spin a byssus ; the oyster and spondylus 
attach themselves by spines or leafy expansions of their shell ; 
the hrachiopoda are all fixed by similar means, and even some 
of the gasteropods become voluntary prisoners, as the hipponyx 
and vermetus. 



8 MANUAL OF THE MOLLUSCA. 

Other tribes retain the power of travelling at will, and shift 
their quarters periodically, or in search of food; the river- 
mussel drags itself slowly along by protruding and contracting 
its flexible foot ; the cockle and trigonia have the foot bent, 
enabling them to make short leaps ; the scallop {peden opercu- 
laris) swims rapidly by opening and shutting its tinted valves. 
Nearly all the gasteropods creep like the snail, though some are 
much more active than others ; the pond- snails can glide along 
the surface of the water, shell downwards ; the nucleobranchs 
and pteropods swim in the open sea. The cuttle-fish have a 
strange mode of walking, head downwards, on their outspread 
arms ; they can also swim with their fins, or with their webbed 
arms, or by expelling the water forcibly from their branchial 
chamber; the calamary can even strike the surface of the sea 
with its tail, and dart into the air like the flying-fish. — {Owen.) 

By these means the mollusca have spread themselves over 
every part of the habitable globe ; every region has its tribe ; 
every situation its appropriate species ; the land-snails frequent 
moist places, woods, sunny banks and rocks, climb trees, or 
burrow in the ground. The air-breathing limneids live in 
fresh- water, only coming occasionally to the surface ; and the 
auriculas live on the sea-shore, or in salt-marshes. In the sea 
each zone of depth has its molluscous fauna. The limpet and 
periwinkle live between tide-marks, where they are left dry 
twice a day ; the trochi and purpurce are found at low water, 
amongst the sea- weed; the mussel affects muddy shores, the 
cockle rejoices in extensive sandy flats. Most of the flnely- 
coloured shells of the tropics are found in shallow water, or 
amongst the breakers. Oyster-banks are usually in four or 
five fathoms water; scallop-banks at twenty fathoms. The 
terehratulce are found at still greater depths, commonly at fifty 
fathoms, and sometimes at one hundred fathoms, even in Polar 
seas. The fairy-like pteropoda, the oceanic snail, and multi- 
tudes of other floating molluscs, pass their lives on the open 
sea, for ever out of sight of land ; whilst the litiopa and scylloea 
follow the gulf- weed in its voyages, and feed upon the green 
delusive banks. 

The food of the mollusca is either vegetable, infusorial, or 
animal. All the land-snails are vegetable-feeders, and their 
depredations are but too well known to the gardener and 
farmer ; many a crop of winter corn and spring tares has been 
wasted by the ravages of the "small grey slug." They have 
their likings, too, for particular plants, most of the pea-tribe 
and cabbage-tribe are favourites, bnt they hold white mustard 



HABITS AND ECONOMY OP THE MOLLTTSCA. 9 

in abhorrence, and fast or shift their quarters while that crop ig 
on the ground.* Some, like the " cellar- snail," feed on crypto- 
gamic vegetation, or on decaying leaves ; and the slugs are 
attracted by fungi, or any odorous substances. The round- 
mouthed sea-snails are nearly all vegetarians, and consequently 
limited to the shore and the shallow waters in which sea-weeds 
grow. Beyond fifteen fathoms, almost the only vegetable pro- 
duction is the nullipore ; but here corals and horny zoophytes 
take the place of algce, and afford a more nutritious diet. 

The whole of the bivalves, and other headless molluscs live 
on infusoria, or on microscopic plants, brought to them by the 
current which their ciliary apparatus perpetually excites ; such, 
too, must be the sustenance of the magilus, sunk in its coral 
bed, and of the calyptrcea, fettered to its birth-place by its cal- 
careous foot. 

The carnivorous tribes prey chiefly on other shell-fish, or on 
zoophytes ; since, with the exception of the cuttle-fishes, their 
organisation scarcely adapts them for pursuing and destroying 
other classes of animals. One remarkable exception is formed 
by the stilifer, which lives parasitically on the star-fish and sea- 
urchin ; and another by the testacella, which preys on the 
common earth-worm, following it in its burrow, and wearing 
a buckler, which protects it in the rear. 

Most of the siphonated univalves are animal-feeders ; the 
carrion-eating stromb and whelk consume the fishes and other 
creatures, whose remains are always plentiful on rough and 
rocky coasts. Many wage war on their own relatives, and 
take them by assault ; the bivalves may close, and the oper- 
culated nerite retire into his home, but the enemy, with rasp- 
like tongue, armed with siliceous teeth, files a hole through 
the shell, — vain shield where instinct guides the attack ! Of 
the myriads of small shells which the sea heaps up in every 
sheltered " ness," a large proportion will be found thus bored 
by the whelks and purples; and in fossil shell-beds, such as 
that in the Touraine, nearly half the bivalves and sea-snails 
are perforated, — the relics of antediluvian banquets. 

This is on the shore, or on the bed of the sea ; far away from 
land the carinaria and Jirola pursue the floating acalephe ; and 
the argonaut, with his relative the spirula, both carnivorous, 
are found in the "high seas," in almost every quarter of the 
globe. The most active and rapacious of all are the calamaries 



* Dilute lime-water and very weak alkaline solutions are more fatal to snails thaa 
even salt. 

B 3 



10 MAliTTJAL OF THE MOLLTTSCA. 

and cuttles, wlio vindicate their higli position in the nattiraiists' 
" system," by preying even on fishes. 

As the shell-fish are great eaters, so in their turn they afibrd 
food to many other creatures ; fulfilling the universal law of 
eating and being eaten. Civilised man stUl swallows the 
oyster, although snails are no longer reckoned "a dainty dish;" 
mussel, cockles, and periwinkles are in great esteem with 
children and the other unsophisticated classes of society ; and 
so are scallops and the lialiotis, where they can be obtained. 
Two kinds of whelk are brought to the London market in great 
quantities; and the arms of the cuttle-fish are eaten by the 
Neapolitans, and also by the East Indians and Malays. In 
seasons of scarcity, vast quantities of shell-fish are consumed 
by the poor inhabitants of the Scotch and Irish coasts.* Still 
more are regularly collected for bait; the calamary is much 
used in the cod-fishery, ofi" Newfoundland, and the limpet and 
whelk on our own coasts. 

Many wild animals feed on shell-fish ; the rat and the raccoon 
seek for them on the sea-shore when pressed by hunger ; the 
South American otter, and the crab- eating opossum constantly 
resort to salt-marshes, and the sea, in order to prey on the 
mollusca ; the great whale lives habitually on the small floating 
pteropods ; sea-fowl search for the littoral species at every 
ebbing tide; whilst, in their own element, the marine kind 
are perpetually devoured by fishes. The haddock is a " great 
conchologist ; " and some rare northern sea-shells have been 
rescued, unbroken, from the stomach of the cod ; whilst even 
the strong valves of the cyprina are not proof against the teeth 
of the cat-fish {(marhicas). 

They even fall a prey to animals much their inferiors in 
sagacity ; the star-fish swallows the small bivalve entire, and 
dissolves the animal out of its shell; and the bubble-shell 
(jpMline), itself predacious, is eaten both by star-fish and sea- 
anemone {actinia). 

The land-snails afibrd food to many birds, especially to the 
thrush tribe ; and to some insects, for the luminous larva of 
the glow-worm lives on them, and some of the large predacious 
beetles (e.g., carahus violaceus and goerius olens), occasionally 
kill slugs. 

The greatest enemies of the mollusca, however, are those of 

* See Hugh Miller's " Scenes and Legends of the North of Scotland." The Kjok- 
henmbdings, or kitchen refuse-heaps, which have been found so abundantly in Den- 
mark, Scotland, New Zealand, and elsewhere, are sometimes hundreds of yards in 
length, and composed almost entirely of shells. 



HABITS AND ECONOMY OF THE MOLLTJSCA. 11 

their own nation. Scarcely one-half the shelly tribes graze 
peacefully on sea-weed, or subsist on the nutrient particles 
which the sea itself brings to their mouths ; the rest browse 
on living zoophytes, or prey upon the vegetable -feeders. 

Yet in no class is the instinct of " self-preservation" stronger, 
nor the means of defence more adequate ; their shells seem 
expressly given to compensate for the slowness of their move- 
ment, and the dimness of their senses. The cuttle-j&sh escapes 
from attack by swimming backwards and beclouding the water 
with an inky discharge ; and the sea-hare {aplysia) pours out, 
when irritated, a copious purple fluid, formerly held to be 
poisonous. Others rely on passive resistance, or on conceal- 
ment, for their safety. It has been frequently remarked that 
molluscs resemble the hue and appearance of the situation they 
frequent ; thus, the limpet is commonly overgrown with halani 
and sea-weed, and the ascidian with zoophytes, which form an 
effectual disguise ; the lima and modiola spin together a screen 
of grotto-work. One ascidian (a. cochligera) coats itself with 
shell-sand, and the carrier-trochus cements shells and corals to 
the margin of its habitation, or so loads it with pebbles, that 
it looks like a little heap of stones. 
' It must be confessed that the instincts of the shell-fish are 
of a low order, being almost limited to self-preservation, the 
escape from danger, and the choice of food. An instance of 
something like social feeling has been observed in a Eoman 
snail [helix pomatia), who, after escaping from a garden, re- 
turned to it in quest of his fellow-prisoner; — but the accom- 
plished naturalist who witnessed the circumstance hesitated to 
record a thing so unexampled. The limpet, tod, we learn from 
the observations of Mr. George Eoberts, of Lyme Eegis, is fond 
of home, or at least possesses a knowledge of topography, and 
returns to the same roost after an excursion with each tide. 
Professor Forbes has immortalised the sagacity of the razor- 
fish, who .submits to be salted in his hole, rather than expose 
himself to be caught, after finding that the enemy is lying in 
wait for him. On the other hand, Mr. Bowerbank has a curious 
example of "instinct at fault," in the fossil spine of a sea- 
urchin, which appears to have been drilled by a carnivorous 
gasteropod. 

We have spoken of shell-fish as articles of f^'^ but they have 

other uses, even to man; they are the toys of children, who 

hear in them the roaring of the sea ; they are the pride of 

" collectors " — whose wealth is in a cone or " wentle-trap ; " * 

* The extravagant prices tliat have been given for rare shells are less to be regretted, 



■1'2 MAIS-UAL OF IHE MOLLTJSCA. 

and they are tlie ornaments of barbarous tribes. Tbe Friendly- 
Islander wears the orange -cowry as a mark of chieftainship 
{Stutchbury), and the New Zealander polishes the elenchus into 
an ornament more brilliant than the "pearl ear-drop" of 
classical or modern times. {Clarke.) One of the most beautiful 
substances in nature is the shell-opal, formed of the remains of 
the ammonite. The forms and colours of shells (as of all other 
natural objects), answer some particular purpose, or obey some 
general law ; but besides this, there is much that seems specially 
intended for our study, and calculated to call forth enlightened 
admiration. Thus the tints of many shells are concealed during 
life by a dull external coat, and the pearly halls of the nautilus 
are seen by no other eyes than ours. Or descending to mere • 
** utility," how many tracts of coast are destitute of limestone, 
but abound in shell-banks which may be burned into lime ; or 
m shell-sand, for the use of farmers.* 

Not much is known respecting the individual duration of the 
shell-fish, though their length of life must be very variable. 
Many of the aquatic species are annuals, fulfilling the cycle of 
their existence in a single year ; whole races are entombed in 
the wintry tide of mud that grows from year to year in the beds 
of rivers, and lakes, and seas ; thus, in the Wealden clay we 
find layer above layer of small river-snails, alternating with 
thin strata of sediment, the index of immeasurably distant 
years. Dredgers find that whilst the adults of some shell-fish 
can be taken at all seasons, others can be obtained late in the 
autumn or winter only ; those caught in spring and summer 
being young, or half-grown ; and it is a common remark that 
dead shells (of some species) can be obtained of a larger size 
than any that we find alive, because they obtain their full 
growth at a season when our researches are suspended. Some 
species require part of two years for their full development ; 
the young of the doris and eoUs are born in the summer time, 
in the warm shallows, near the shore; on the approach of 

because they have induced voyagers to collect. Mere shell-collecting, however, is no 
more scientific than pigeon- fan eying, or the study of old china. For educational pur- 
poses the best shells are the typea of genera, or species vrhich illustrate particular 
points of structure ; and, fortunately for students, the prices liave been much diminished 
of late years. A CariTzar/a, once " worth 100 guineas" (Sowerby), is now worth Is. 
only ; a wentle-trap which fetched 40 guineas in 1701 ( Rumphius) was worth only 
20 guineas in 1753, and may now be had for 5s. The Conus gloria-maris has fetched 
£50 more than once, and Cyprcea umbilicata has been sold for £30. 

* Shell-sand is only beneficial on peaty soils, or heESry clay land. It sometimes 
hardens into limestone, as on the coast of Devon ; and at Guadaloupe, where it con- 
tains littoral shells and human skeletons of recent date. 



HAEITS AND ECONOMY OF THE MOLLTJSCA. 13 

winter they retire to deeper water, and in the following spring 
return to the tidal rocks, attain their full growth early in the 
summer, and after spawning-time disappear. 

The land-snails are mostly biennial ; hatched in the summer 
and autumn, they are half-grown by the winter time, and 
acquire their full growth in the following spring or summer. 
In confinement, a garden-snail will live for six or eight years ; 
but in their natural state it is probable that a great many die 
in their second winter, for clusters of empty shells may be 
found, adhering to one another, under ivied walls, and in other 
sheltered situations ; the animals having perished in their 
hybernation. Some of the spiral sea-shells live a great many 
years, and tell their age in a very plain and interesting man- 
ner, by the number of fringes {varices) on their whorls ; the 
contour of the ranella and murex depends on the regular re- 
currence of these ornaments which occur after the same inter- 
vals in well-fed individuals, as in their less fortunate kindred. 
The ammonites appear by their varices, or periodic mouths 
(PI. III., fig. 3), to have lived and continued growing for many 
years. 

Many of the bivalves, like the mussel and cockle, attain their 
full growth in a year. The oyster continues enlarging his shell 
by annual " shoots," for four or five years, and then ceases to 
grow outwards ; but very aged specimens may be found, espe- 
cially in a fossil state, with shells an inch or two in thickness. 
The giant-clam {tridacna), which attains so large a size that 
poets and sculptors have made it the cradle of the sea-goddess, 
must enjoy an unusual longevity ; living in the sheltered 
lagoons of coral islands, and not discursive in its habits, the 
corals grow up around until it is often nearly buried by them ; 
but although there seems to be no limit to its life (though it may 
live a century for all that we know), yet the time will probably 
come when it will be overgrown by its neighbours, or choked 
with sediment. 

The fresh-water molluscs of cold climates bury themselves 
during winter in the mud of ponds and rivers ; and the land- 
snails hide themselves in the ground, or beneath moss and 
dead leaves. In warm climates they become torpid during the 
hottest and driest part of the year. 

Those genera and species which are most subject to this 
" summer sleep " are remarkable for their tenacity of life ; and 
numerous instances have been recorded of their importation 
from distant countries in a living state. In June, 1850, a 
living pond-mussel was sent to Mr. Gray from Australia, which 



14 ' MAKTJAl OP THE MOLLTTSCA. 

had been more than a year out of water.* The pond-snails 
{ampuUarice) have been found alive in logs of mahogany from 
Honduras (Mr. Pickering) ; and M. Caillaud carried some from 
Egypt to Paris packed in saw-dust. Indeed, it is not easy to 
ascertain the limit of their endurance ; for Mr. Laidlay having 
placed a number in a drawer for this purpose, found them alive 
after ^five years, although in the warm climate of Calcutta. The 
cydosfomas, which are also operculated, are well known to survive 
imprisonments of many months; but in the ordinary land- 
snails such cases are more remarkable. Some of the large 
tropical hulimi, brought by Lieutenant Graves from Valparaiso, 
revived after being packed, some for thirteen, others for twenty 
months. In 1849 Mr. Pickering received from Mr. Wollaston 
a basket-full of Madeira snails (of twenty or thirty different 
species), three-fourths of which proved to be alive after several 
months' confinement, including a sea voyage. Mr. Wollaston 
has himself told us that specim.ens of two Madeira snails [helix 
papilio and tectiformis) survived a fast and imprisonment in 
pill-boxes of two years and a half, and that a large number of 
the small helix turricida, brought to England at the same time, 
were all living after having been enclosed in a dry bag for a 
year and a half. 

But the most interesting example of resuscitation occurred to 
a specimen of the Desert snail, from Egypt, chronicled by Dr. 
Baird.f This individual was fixed to a tablet in the British 
Museum on the 25th of March, 1846 ; and on the 7th of March, 
1850, it was observed that he must have come out of his shell 
in the interval (as the paper had been discoloured, apparently 
in his attempt to get away) ; but finding escape impossible, had 
again retired, closing his aperture with the usual glistening 
film ; this led to his immersion in tepid water and marvellous 
recovery. Advantage was taken of this circumstance for making 
a sketch of the living animal (Fig. 2). 

The permanency of the shell-bearing races is effectually pro- 
vided for by their extreme fecundity ; and though exposed to a 
hundred dangers in their early life enough survive to re-people 
the land and sea abundantly. The spawn of a single doris may 
contain ,600,000 eggs (Darwin) ; a river-mussel has been esti- 
mated to produce 300,000 young in one season, and the oyster 
cannot be much less prolific. The land-snails have fewer enemies, 
and lay fewer eggs. 

* " It was alive 498 daj's after it was taken from the pond ; and m the interim 
had been onlj' twice for a few hours in water, to see if it was alive."— iJer. TV. O. 
Neicnham. t Ann. Nat. Hist. 1850. 



STEUCTUEE and rHTSIOLOGT OF THE MOLLUSCA. 15 

Lastly, tlie mollusca exhibit the same instinctiye care with 
insects and the higher animals in placing their eggs in situations 
where they will be safe from injury, or open to the influences 
of air and heat, or surrounded by the food which the young 
will require. The tropical hulimi cement leaves together to 
protect and conceal their large bird-like eggs ; the slugs bury 
theirs in the ground ; the oceanic-snail attaches them to a 
floating raft ; and the argonaut carries them in her frail boat. 




Fig. 9. lantliina with its raft. 

The horny capsules of the whelk are clustered in groups, with 
spaces pervading the interior for the free passage of sea water ; 
and the nidamental ribbon of the doris and eolis is attached to a 
rock or some solid surface from which it will not be detached by 
the waves. The river-mussel and cydaa carry their parental 
care still further, and nurse their young in their own mantle, 
or in a special marsupium, designed like that of the opossum, 
to protect them until they are strong enough to shift for 
themselves. 

If any one imbued with the spirit of Paley or Chateaubriand, 
should study these phenomena, he might discover more than 
the " barren facts " which alone appear without significance to 
the unspiritual eye; he would see at every step fresh proofs of 
the wisdom and goodness of God, who thus manifests His great- 
ness by displaying the same care for the maintenance of His 
feeblest creatures as for the well-being of man and the stability 
of the world. 

Stetjcttjhe and Physiology of the Mollusca. 

Molluscous animals possess a distinct nervous system, instru- 
ments appropriated to the five senses, and muscles by which 
they execute a variety of movements. They have organs, by 
which food is procured and digested ; a heart, with arteries 
and veins, through which their colourless fluids circulate ; a 



16 MAinrAL OP THE MOLLTTSCA. 

breathing-organ ; and, in most instances, a protecting shell. 
They produce eggs, and the young generally pass through 
one preparatory, or larval, stage. 

The nervous system, upon which sensation and the exercise of 
.muscular motion depend, consists of a brain or principal centre, 
and of various nerves possessing distinct properties : the optic 
nerves are only sensible of light and colours; the auditory 
nerves convey impressions of sound ; the olfactory, of odours ; 
the gustatory, of flavours ; whilst the nerves of touch or feeling 
are widely diffused, and indicate in a more general way the 
presence of external objects. The nerves by which motion is 
produced are distinct from these, but so accompany them as to 
appear like parts of the same cords. Both kinds of nerves 
cease to act when their connection with the centre is interrupted 
or destroyed. There is reason to believe that most of the move- 
ments of the lower animals result from the reflection of external 
stimulants (like the process of hreatJiing in man), without the 
intervention of the will.* 

In the moUusca, the principal part of the nervous system is a 
ring surrounding the throat (ossophagus), and giving off nerves 
to different parts of the body. The points from which the 
nerves radiate are enlargements termed centres {ganglia), those 
on the sides and upper part of the ring represent the brain, and 
supply nerves to the eyes, tentacles, and mouth ; other centres, 
connected with the lower side of the oesophageal ring, send 
nerves to the foot, viscera, and respiratory organ. In the 
bivalves the branchial centre is the most conspicuous, and is 
situated on the posterior adductor muscle. In the tunicaries 
the corresponding nervous centre may be seen between the two 
orifices in the muscular tunic. This scattered condition of the 
nervous centres is eminently characteristic of the entire sub- 
kingdom. 

Organs of special sense. — Sight. The eyes are two in number, 
placed on the front or sides of the head ; sometimes they are 
sessz7e,in others stalked, or placed on long pedicels (ommatophora). 
The eyes of the cuttle-fishes resemble those of fishes in their 
large size and complicated structure. Each consists of a strong 
fibrous globe [sclerotic], transparent in front [cornea), with the 
opposite internal surface [retina) covered by a dark pigment 
which receives the rays of light. This chamber is occupied by 
an aqueous humour, a crystalline lens, and a vitreous humour, 
as in the human eye. In the strombidce, the eye is not less 
highly organised, but in most of the gasteropoda it has a more 
* See " Miiller's Elements of P]iysiology," edited by Dr. Baiy. 



STRUCTFEE AND PHYSIOLOGY OF THE MOLLUSCA. 



17 



simple structure, and perhaps only possesses sensibility of light 
without the power of distinct vision. The larval bivalves have 
also a pair of eyes in the normal position (Fig. 30) near the 
mouth ; but their development is not continued, and the adults 
are either eyeless, or possess merely rudimentary organs of 
vision, in the form of black dots {ocelli) along the margin of the 
mantle.* These supposed eyes have been detected in a great 




^ffi, 



Fig. 10. Pecten varius.^ 

many bivalves, but they are most conspicuous in the scallop, 
which has received the name of argus from Poli on this account 
(Fig. 10). 

In the tunicaries similar ocelli are placed between the tentacles 
which surround the orifices. 

Sense of Hearing. In the highest cephalopods, this organ 
consists of two cavities in the rudimentary cranium which pro- 
tects the brain ; a small calcareous body or otolithe is suspended 




Fig. 11. Tentacle of a Nudibranch-J 

in each, as in the vestibular cavities of fishes. Similar auditory 
capsules occur near the base of the tentacles m the gasteropoda, 
and they have been detected, by the vibration of the otolithes, 
in many bivalves and brachiopods. With the exception of 

* " Each possesses a cornea, lens, choroid, and nerve ; they are, without doubt, 
organs- of vision." (Garner.) The same conclusion is amved at by Duvemoy in a 
paper in the Annales des Sciences Naturelles for 1852. 

t Pecten varius, L., from a specimen dredged by Mr. Bowerbank, off Tenby . 
m, the paUial cmtains ; br, the branchiae. 

X Fig. 11. Tentacle of Eolis coronata, Forbes, from Alder and Hancock. 



18 MANUAL OF THE MOLLTTSCA. 

tritonia and eolis, none of the mollusca have been observed to 
emit sounds. (Grant.) 

Sense of Smell. This faculty is evidently possessed by the 
cuttle-fishes and gasteropods ; snails discriminate their food by 
it, slugs are attracted by offensive odours, and many of the 
marine zoophaga may be taken with animal baits. In the pearly 
nautilus there is a hollow plicated process beneath each eye, 
which M. Yalenciennes regards as the organ of smell.* Messrs. 
Hancock and Embleton attribute the same function to the 
lamellated tentacles of the nudibranchs, and compare them with 
the olfactory organs of fishes. 

The labial tentacles of the bivalves are considered to be 
organs for discriminating food, but in what way is unknown 
(Fig. 18, I, t). The sense of taste is also indicated rather by the 
habits of the animals and their choice of food than by the 
structure of a special organ. The acephala appear to exercise 
little discrimination in selecting food, and swallow anything 
that is small enough to enter their mouths, including living 
animalcules, and even the sharp spicula of sponges. In some 
instances, however, the oral orifice is well guarded, as in pecten 
(Fig. 10). In the Encephala the tongue is armed with spines, 
employed in the comminution of the food, and cannot possess a 
very delicate sense. The more ordinary and diffused sense of 

touch is possessed by all the 
mollusca ; it is exercised by the 
skin, which is everywhere soft 
and lubricous, and in a higher 
degree by the fringes of the bi- 
valves (Fig. 12), and by the fila- 
ments and tentacles [vibracula) 

of the gasteropods ; the eye- 
Fig. 12. Lepton squamosum^ j • i n jt •^ • i / 1 

pedicels of the snail are evidently 

endowed with great sensitiveness in this respect. That shell-fish 

are not very sensible of pain, we may well believe, on account 

of their tenacity of life, and the extent to which they have the 

power of reproducing lost parts. 

Muscular System. The muscles of the mollusca are principally 

connected with the skin, which is exceedingly contractile in 

every part. The snail affords a remarkable, though familiar 

instance, when it draws in its eye-stalks by a process like the 

* Mr. Owen reojards the membranous lamellce between the oral tentacles and in 
front of the mouth, as the seat of the olfactory sense. See Fig. 51. 

t Fig. 12. Lepton squamosum, Mont., from a drawing by JMr. Alder, in the Srit^ 
Mollusca ; copied by permission of Mr. Van Voorst. 





STRTJCTFEE AND PHYSIOLOGY OF THE MOLLUSCA. 19 

in version of a glove-finger ; the branching gills of some of 
the sea-slugs, and the tentacles of the cuttle-fishes are also 
eminently contractile.* 

The inner tunic of the ascidians (Fig. 8, t) presents a beautiful 
example of muscular tissue, the crossing fibres having much 
the appearance of basket-work ; in the transparent salpians, 
these fibres are grouped in flat bands, and arranged in charac- 
teristic patterns. In this class [tunicata] they act only as 
sphincters (or circular muscles), and by their sudden contraction 
expel the water from the branchial cavity. The muscular foot 
of the bivalves is extremely flexible, having layers of circular 
fibres for its protrusion (Fig. 18, /), and longitudinal bands for 
its retraction (Fig. 30 *) ; its structure and mobility has been 
compared to that of the human tongue. 
In the burrowing shell-fish (such as 
solen) , it is very large and powerful, and 
in the boring species, its surface is 
studded with siliceous particles {spieula), 
which renders it a very efiicient instru- 
ment for the enlargement of their cells. 
{Hancock). In the attached bivalves it 
is not developed, or exists only in a rudi- ^ig- ^^- DreissenaA 
mentary state, and is subsidiary to a gland which secretes the 
m.aterial of those threads with which the mussel and pinna 
attach themselves (Fig. 13). These threads are termed the 
hyssus ; the plug of the anomia and the pedicel of terehratula 
are modifications of the hyssus. 

In the cuttle-fishes alone we find muscles attached to internal 
cartilages which represent the bones of vertebrate animals ; the 
muscles of the arms are inserted in a cranial cartilage, and those 
of the fins in the lateral cartilages. 

Muscles of a third kind are attached to the shell. The valves 
of the oyster (and other mono-myaries) are connected by a 
single muscle; those of the cytherea (and ocner di-myaries), by 
two ; the contraction of which brings the valves together. 
They are hence named adductors; and the part of the shell 



* The muscular fibres of molluscs frequently present the transverse stripes which 
characterise voluntary muscles in the higher animals. Striped muscular fibre has been 
• observed in Sal pa {Huxley); and in Waldheimia austrnlis by Hancock; a strict search 
was made by that able anatomist for the purpose of discovering such fibre amongst the 
liingeless brachiopods, but without success. Striped fibres have been seen in the 
gasteropods. 

t Fig. IS. Breissena polymorpha (Pallas sp.), from the SuiTey timber-docks. 
f, foot ; b, byssus. 



20 



MANUAL OF THE MOLLUSC A. 



to which, they are attached is always indicated by scars 
(Fig. 14, a, a'). 

The border of the mantle is also muscular, and the place of 
its attachment is marked in the shell by a line called the pallial 
impression {p) ; the presence of a bay, or sinus (s), in this line, 
shows that the animal had retractile siphons ; the foot of the 
animal is withdrawn by retractor muscles also attached to the 




Fig. 14. Left valve of Cytherea chione.* 

shell, and leaving small scars near those of the adductors 
(Fig 30*). 

The gasteropods withdraw into their shells when alarmed, by 
a shell-muscle, which passes into the foot, or is attached to the 
operculum ; its impression is horse -shoe-shaped in the limpet, 
as also in navicella, concholepas, and the nautilus ; it becomes 
deeper with age. In the spiral univalves, the scar is less con- 
spicuous, being situated on the columella, and sometimes divided, 
forming two spots. It corresponds to the posterior retractors in 
the bivalves. 

Digestive System. This part of the animal economy is all- 
important in the radiate classes, and scarcely of less consequence 
in the mollusca. In those bivalves, which have a large foot, the 
digestive organs are concealed in the upper part of that organ ; 
the mouth is unarmed, except by two pairs of soft membranous 



* Fig 14. Cytherea chione, L., coast of Devon (original); h, the hinge ligament; 
u, the umbo ; I, the lunule ; c. cardinal tooth \ tt', lateral teeth ; a, anterior adductor ; 
a', posterior adductor; p, pallial impression; 5, sinus, occupied by retractor of the 
siphons. 



STETTCTTJEE AND PHTSIOLOaT OF THE MOLLUSCA. 21 

palpi, which look like accessory gills (Fig. 18, I, t). The 
ciliated arms of the brachiopods occupy a similar position 
(Figs. 4, 5, 6). The encephalous moUusca are frequently armed 
with horny jaws, working yertically like the mandibles of a 
bird ; in the land-snails, the upper jaw is opposed only by the 
denticulated tongue, whilst the limneids have two additional 
horny jaws, acting laterally. The tongue is muscular and 
armed with recurved spines (or Ungual teeth), arranged in a 
great variety of patterns, which are eminently characteristic of 
the genera.* Their teeth are amber-coloured, glossy, and 
translucent ; and being siliceous (they are insoluble in acid), 
they can be used like a file for the abrasion of very hard sub- 
stances. With them the limpet rasps the stony nullipore, the 
whelk bores holes in other shells, and the cuttle-fish doubtless 
uses its tongue in the same manner as the cat. The tongue, or 
lingual ribbon, usually forms a triple band, of which the central 
part is called the racTiis, and the lateral tracts pleurm, the 
rachidian teeth sometimes form a single series, overlapping 




Fig. 15. Lingual Teeth of MoUusca. 

each other, or there are lateral teeth on each side of a median 
series. The teeth on the pleurae are termed uncini ; they 
are extremely numerous in the plant-eating gasteropods (Fig. 
15, A).t 
Sometimes the tongue forms a short semicircular ridge, con- 

* The preparation of the lingual ribbon as a permanent microscopic object, requires 
some nicety of manipulation, but the arrangement of the teeth may be seen by merely 
compressing part of the animal between two pieces of glass. 

t Fig. 15. A, lingual teeth of ^t'ocAms cinerarius (after Lov en). Only the median 
tooth, and the (5) lateral teeth, and (90) uncini of one side of a single row are repre- 
sented. B, one row of the Ungual teeth of cyprcea europcea ; consisting of a median 
tooth and tlu-ee uncini on each side of it. 



22 



MAIiTUAL OF THE MOLLUSC A. 



tained between the jaws ; at others, it is extremely elongated, and 
its folds extend backwards to the stomach. The lingual ribbon of 
the limpet is longer than the whole animal ; the tongue of the 
whelk has 100 rows of teeth ; and the great slug has 160 rows, 
with 180 teeth in each row. 

The front of the tongue is frequently curyed, or bent quite 
over ; it is the part of the instrument in use, and its teeth are 
often broken or blunted. The posterior part of the lingual 




Fig. 16. Tongue of the Whelk;* 

ribbon usually has its margins rolled together and united, form- 
ing a tube, which is presumed to open gradually. The new 
teeth are developed from behind forwards, and are brought 
successively into use, as in the sharks and rays amongst fishes. 
In the iuUidce the rachis of the tongue is unarmed, and the 
business of comminuting the food is transferred to an organ 
which resembles the gizzard of a fowl, and is often paved with 

calcareous platen, so large and strong 
ill \((^^>^\ ^^ ^^ crush the small shell- fish which 

are swallowed entire. In the aplysia, 
which is a vegetable-feeder, the gizzard 
is armed with numerous small plates 
and spines. The stomach of some 
bivalves contains an instrument called 
Fig. 17. Gizzard of Bulla, f ^he " crystalline stylet," which is con- 
jectured to have a similar use. In the cephalopods there is a 
crop in which the food may accumulate, as well as a gizzard for 
its trituration. 

The liver is always large in the moUusca (Fig. 10) ; its secre- 
tion is derived from arterial blood, and is poured either into the 
stomach or the commencement of the intestine. In the nudi- 





* Fig. 16. Lingual ribbon of iuccinum undatum (original), from a preparation 
communicated by W. Thomson, Esq., of King's College, a, anterior ; p, posterior ; 
I, lateral ; r, rachidian. 

t Fig. 17. Gizzard of bulla lignaria (original). Front and side view of a half- 
growT! specimen, with the part nearest the head of the animal downwards ; in the 
front view the plates are in contact. The cardiac orifice is in the centre, in front ; the 
pyloric orifice is on tlie posterior dorsal side, neai- the small transverse plate. 



STETTCTUKE AND PHYSIOLOGY OF THE MOLLIJSCA. 23 

branclis, whose stomaclis are often remarkably branclied, tbe 
liver accompanies all the gastric ramifications, and even enters 
the respiratory papillae on the backs of the eolids. The exist- 
ence of a renal organ has been ascertained in most classes ; in 
the bivalves it was detected by the presence of uric acid. The 
intestine is more convoluted in the herbivorous than in the 
carnivorous tribes : in the bivalves and in haliotis it passes 
through the ventricle of the heart ; its termination is always 
near the respiratory aperture (or the excurrent orifice, where 
there are two*), and the excrements are carried away by the 
water which has already passed over the gills. 

Besides the organs already mentioned, the encephalous 
molluscs are always furnished with well-developed salivary 
glands, and some have a tudimentary pancreas ; many have also 
special glands for the secretion of coloured fluids, such as the 
purple of the murex, the violet liquid of ianthina and aplysia, 
the yellow of the hullidce, the milky fluid of eolis and the inky 
secretion of the cuttle-fishes. The gland that secretes this 
fluid is situated on the mantle. It consists of a thin layer of 
elongated cells, and is to be found in most gasteropods. The 
fluid produced appears to have diflerent properties in difl'erent 
species. Thus in aplysia and some snails it possesses colour at 
the moment of being secreted; but in others it is colourless, as, 
for instance, in turbo littoralis and trochus cinerarius. In murex 
and purpura also it is colourless when secreted ; but on being 
exposed to the sun it becomes first yellowish and ultimately 
violet, after having passed through various intermediate tints 
formed by the mixture of yellow, blue, and red. According to 
M. Lacaze Duthiers it is probable that the Eomans obtained 
their purple dye from three or four species of mollusc, such as 
murex trunculus, and hrandaris, and purpura hcemastoma. A 
few molluscs exhale peculiar odours, like the garlic- snail {helix 
alliaria) and eledone TnoscJiata. Many are phosphorescent, espe- 
cially the floating tunicaries [salpa and pyrosoma), and bivalves 
which inhabit holes {pJioladidce). Some of the cuttle-fishes are 
slightly luminous ; and one land-slug, the phosphorax, takes its 
name from the same property. 

Circulating system. The mollusca have no distinct absorbent 
system, but the product of digestion {chyle) passes into the 
general abdominal cavity, and thence into the larger veins ; 

* In most of the gasteropods the intestine returns upon iiself, and terminates on the 
right side, near the head. Occasionally it ends in a perforation more or less removed 
from the margin of the apertm-e, as in trcchotoma, fissurella, macrochisma, and 
dentalium. In chiton the intestine is straight, and terminates posteriorly. 



24 MANTTAL OF THE MOLLTJSCA. 

whicli are perforated witli numerous round apertures. Tlie 
circulating organs are the heart, arteries, and veins ; the blood 
is colourless, or pale bluish white. The heart consists of an 
auricle (sometimes divided into two), which receives the blood 
from the gills ; and a muscular ventricle which propels it into 
the arteries of the body. Prom the capillary extremities of the 
arteries it collects again into the veins, circulates a second time 
through the respiratory organ, and returns to the heart as 
arterial blood. Besides this systemic heart, the circulation is 
aided by two additional 'branchial hearts in the cuttle-fishes. 
Mr. Alder has counted from 60 to 80 pulsations per minute in 
the nudibranchs, and 120 per minute in a vitrina. Both the 
arteries and veins form occasionally wide spaces, or sinuses ; in 
the cuttle-fishes the oesophagus is partly or entirely surrounded 
by a venous sinus ; and in the acephala the visceral cavity itself 
forms part of the circulating system. 

Aquiferous system. Eecent anatomical researches by Messrs. 
Hancock, Eolleston, Eobertson, Williams, and others have 
thrown considerable doubt upon the existence of any aquiferous 
system in the moUusca. There are certainly a number of pores 
which open to the external water ; these are situated either in 
the centre of the creeping disc, as in cyprcea, conus, and ancil- 
laria ; or at its margin, as in haliotis, doris, and aplysia. In 
the cuttle-fishes they are variously placed, on the sides of the 
head, or at the bases of the arms ; some of them conduct to the 
large sub-orbital pouches, into which the tentacles are retracted. 
According to Messrs. Eolleston and Eobertson* there is no con- 
nection between the blood vascular and the aquiferous systems; 
and the foot in the lamellibranchiates is distended by means of the 
aquiferous canals, which they regard as a rudimentary kidney. 
Agassiz and Lacaze Duthiers, on the other hand, assert that there 
is a connection between the two systems. The proof relied on 
by the former observers was that when a coloured injection was 
forced in through a vein, and an injection of a difierent colour 
was sent into the aquiferous canals, two coloured systems of 
ramification were formed, which the microscope showed to be 
distinct up to the furthest extremities. Agassiz also used a 
coloured injection ; he states that when it was injected through 
the large pore in the pedal surface of some species of pyrula, 
not only was the system of canals in the foot filled, but also the 
whole of the circulatory system. He also states that when a 
mactra is taken out of the water it discharges a quantity of 
fluid from the foot, which consists of salt water, in which floats 
* Philosophical Transactions, 1862. 



STRrCTTJEE AND PHYSIOLOGY OT THE MOILUSCA. 25 

a large number of blood corpuscles. This lie regards as a proof 
of the mixture of blood and sea water within the body of the 
animal. 

Respiratory system. The respiratory process consists in the 
exposure of the blood to the influence of air, or water contain- 
ing air; during which oxygen is absorbed and carbonic acid 
liberated. It is a process essential to animal life, and is never 
entirely suspended, even during hybernation. Those air- 
breathers that inhabit water are obliged to visit the surface 
frequently; and stale water is so inimical to the water-breathers, 
that they soon attempt to escape from the confinement of a glass 
or basin, unless the water is frequently renewed. In general, 
fresh water is immediately fatal to marine species, and salt 
water to those which properly inhabit fresh ; but there are some 
which affect brackish water, and many which endure it to a 
limited extent. The depth at which shell-fish live is probably 
influenced by the quantity of oxygen which they require ; the 
most active and energetic races live only in shallow water, or 
near the surface ; those found 

in very deep water are the ^ \,,jp!*:^^' 

lowest in their instincts, and \ *\^^^^J|^^sc* 
are specially organised for ^^^^/^^^m^^^b^ 

their situation. Some water- *",^^^1/^^^^^^^*^^l.. o 

breathers require only moist ^ ^^^^^^^^^^^^^®" — "^ * 
sea air, and a bi- diurnal visit #^^^^^^^^^B|^^' ^ 
from the tide — like the peri- '^^^^^^^^^H|^^' 

whilst 'many^ 'air-breather; ^^^^^^^^ 
live entirely m the water or 42a2izi23S:i2i3i^^^ 

in damp places by the water- . 

Side. In fact, the nature of ^ i^ ^ 

the repiratory process is the same, whether it be aquatic or 
aerial, and it is essential in each case that the surface of the 
breathing-organ should be preserved moist. The process is 
more complete in proportion to the extent and minute sub- 
division of the vessels, in which the circulating fluid is exposed 
to the revivifying influence. 

The land- snails {pulmonifera) have a lung or air-chamber, 
formed by the folding of the mantle, over the interior of which 
the pulmonary vessels are distributed; this chamber has a 

* Trigonia pectinata, Lam. (original). Brought from Australia by the late Captain 
Owen Stanley. The giUs are seen in the centre through the transparent mantle. 
0, mouth ; 1 1, labial tentacles ; /, foot ; v, vent. 

C 



26 MANUAL OP THE MOLLTJSCA. 

round orifice, on tlie right side of tlie animal, whicli opens and 
closes at irregular intervals. The air in this cavity seems to 
renew itself with sufficient rapidity (by the law of diffusion), 
without any special mechanism. 

In the aquatic shell-fish respiration is performed by the 
mantle, or by a portion of it specialised, and forming a gill 
(branchia). It is affected by the arms in all the hrachiopoda, 
while the mantle serves as an auxiliary. In the ordinary 
bivalves the gills form two membranous plates on each side of 
the body ; the muscular mantle is still sometimes united, form- 
ing a chamber with two orifices, into one of which the water 
flows, whilst it escapes from the other ; there is a third opening 
in front for the foot, but this in no wise influences the branchial 
circulation. Sometimes the orifices are drawn out into long 
tubes or siphons, especially in those shell-fish which burrow in 
sand (Pigs. 19 and 7). 




Fig. 19. Bivalve vrith long siphons.* 

Those bivalves which have no siphons, and even those in 
which the mantle is divided into two lobes, are provided with 
valves or folds which render the respiratory channels just as 
complete in effect. These currents are not in any way connected 
with the opening and closing of the valves, which is only done 
in moving, or in efforts to expel irritating particles. f 

In some of the gasteropoda the respiratory organs form tufts, 
exposed on the back and sides (as in the nudihranchs), or pro- 
tected by a fold of the mantle (as in the inferohranchs and 
tectihranchs of Cuvier)4 But in most the mantle is inflected, 

* Fig. 19. Psammohia vespertina, Chemn. after Poli, reduced one-half. The arrowa 
indicate the direction of the current ; r s, respiratory siphon ; e s, excurrent siphon ; 
/, foot. 

t If a river-mussel be placed in a glass of water, and fine sand let fall gently over 
its respiratory orifices, the particles will be seen to rebound from the vicinity of the 
upper aperture, whilst they enter the lower one rapidly. But as this kind of food is 
not palatable, the creature will soon give a plunge with its foot, and closing its valves, 
spirt the water (and with it the sand) from both orifices ; the motion of the foot is, of 
course, intended to change its position. 

X Mr. Collingwood (Annals of Nat. Hist, for 1861), in discussing what function these 
tufts or papillae perform, concludes that morphologically and physiologically they are 
not branchise. 



STRUCTimE AND PHYSIOLOGY OP THE MOLLUSCA. 27: 

and forms a vaulted cliamber over the back of the neck, in 
which are contained the pectinated or plume-like gills (Fig. 68). 
In the carnivorous gasteropods [siphonostomata) the water 
passes into this chamber through a siphon, formed by a pro- 
longation of the upper margin of the mantle, and protected by 
the canal of the shell ; after traversing the length of the gill, it 
returns and escapes through a posterior siphon, generally less 
developed, but very long in ovulum volva, and forming a tubular 
spine in typhis. 

In the plant-eating sea-snails {holosfomafa) there is no true 
siphon, but one of the "neck-lappets" is sometimes curled up 
and performs the same office, as in paludina and ampullaria 
(Fig. 109). The in-coming and out-going currents in the 
branchial chamber are kept apart by a valve-like fringe, con- 
tinued from the neck-lappet. The out-current is still more 
effectually isolated in fissurella, haliotis, and dentalium, where 
it escapes by a hole in the shell, far removed from the point at 
which it entered. Near this outlet are the anal, renal, and 
generative orifices. 

The cephalopods have two or four plume-like gills, sym- 
metrically placed in a branchial chamber, situated on the under- 
side of the body ; the opening is in front, and occupied by a 
funnel, which, in the nautilus, closely resembles the siphon of 
the paludina, but has its edges united in the cuttle-fishes. The 
free edge of the mantle is so adapted that it allows the water to 
enter the branchial chamber on each side of the funnel : its 
muscular walls then contract and force the water through the 
fannel, an arrangement chiefly subservient to locomotion.* 
Mr. Bowerbank has observed that the eledone makes twenty 
respirations per minute when resting quietly in a basin of water. 

In most instances, the water on the surface of the gills is 
changed by ciliary action alone ; in the cephalopods and salpians 
it is renewed by the alternate expansion and contraction of the 
respiratory chamber, as in the vertehrate animals. 

The respiratory system is of the highest importance in the 
economy of the moUusca, and its modifications afford most 
valuable characters in classification. It will be observed that 
the Cuvierian classes are based on a variety of particulars, and 
are very unequal in importance ; but the orders are characterised 
by their respiratory conditions, and are of much more nearly 
equal value. 

* A very efficient means of locomotion in the slender poiated calamarios, v\hich 
dait backwards with the recoil, like rockets. 

c2 



28 MANUAL or THE MOLLUSCA. 

Oedkes. Classes. 

Dibranchiata. Owen. . 

Tetrabranchiata. Owen. ^Cephalopoda. 

Nucleobranchiata. Bl, ^ 

ENCEPHALA .... . -( Prosobranchiata. M, Edw. | 

Pulmonifera. Cuv. ^GasteeoPODa. 

Opisthobranchiata. M. Edw. ^ 
^ Aporobranchiata. Bl. Pteeopoda. 

palliobranchiata. Bl. BEAcnioPODA. 

ACEPHALA ./ Lamellibranchiata. Bl. ConchifeBA. 

[Heterobranchiata. Bl. TtiNICATA. 

The Shell. The relation of the shell to the breathing- organ is 
very intimate : indeed, it may be regarded as a pneumo'skeletun, 
being essentially a calcified portion of the mantle, of which the 
breathing-organ is at most a specialised part.* 

The shell is so characteristic of the moUnsca that they have 
been commonly called " testacea " {from, testa, "a shell") in 
scientific books ; and the popular name of " shell-fish," though 
not quite accurate, cannot be replaced by any other epithet in 
common use. In one whole class, however, and in several 
families, there is nothing that would be popularly recognised as 
a shell. 

Shells are said to be external when the animal is contained in 
them, and internal when they are concealed in the mantle ; the 
latter, as well as the shell-less species, being called naJced 
molluscs. 

Three -fourths of the moUusca are univalve, or have but one 
shell; the others are mostly bivalve, or have two shells; the 
pholads have accessory plates, and the shell of chiton consists of 
eight pieces. Most of the multivalves of old authors were 
articulate animals {cirripedes), erroneously included with the 
mollusca, which they resemble only in outward appearance. 

All, except the argonaut, acquire a rudimental shell before 
they are hatched,- which becomes the nucleus of the adult shell ; 
it is often differently shaped and coloured from the rest of the 
shell, and hence the fry are apt to be mistaken for distinct 
species from their parents. 

In cyrnba (Fig. 20) the nucleus is large and irregular; in 

* In its most reduced form the shell is only a hollow cone, or plate, protecting the 
breathing organ and heart, as in Umax, testaceUa, carinaria. Its pecuUar features 
always relate to the condition of the breathing-organ ; and in terebratula and 
pelonaia it becomes identified with the gill. In the nudibranchs the vascular mantle 
performs whoUy or in part the respiratory office. In the cephalopods the shell becomes 
complicated by.the addition of a distinct, internal, chambered portion {phragmocone), 
•which is properly a visceral skeleton ; in spirula the shell is reduced to this ru»^. 



STEirCTURE AlfD PHYSIOLOGY OF THE MOILFSCA. 



29 



fusus antiqnus it is cylindrical; in the pyramidelUdce it is 
oblique ; and it is spiral in carinaria, atlanta, and many limpets, 
■wHch are symmetrical when adult. 

The rudimentary shell of the nudihrancTis is shed at an early 
age, and never replaced. In this respect the moUuscan shell 
differs entirely from the shell of the crab 
and other articulate animals, which is 
periodically cast off and renewed. 

In the bivalves the embryonic shell forms 
the umbo of each valve ; it is often very un- 
like the after-growth, as in unio pictorum, 
cyclas henslowiana, and pecien pusio. In 
attached shells, like the oyster and anomia, 
the umbo frequently presents an exact imita- 
tion of the surface to which the young shell 
orignally adhered. 

Shells are composed of carbonate of lime, 
with a small proportion of animal matter. 
The source of this lime is to be looked for in 
their food. Modern inquiries into organic 
chemistry have shown that vegetables derive 
their elements from the mineral kingdom 
(air, water, and the soil), and animals theirs ^'^- ^^' ^^™*''* 
from the vegetable. The sea-weed filters the salt water, and 
separates lime as well as organic elements ; and lime is one of 
the most abundant mineral matters in land plants. From this 
source the moUusca obtain lime in abundance, and, indeed, 
we find frequent instances of shells becoming unnaturally 
thickened through the superabundance of this earth in their 
systems. On the other hand, instances occur of thin and 
delicate -shelled varieties in still, deep water, or on clay bottoms; 
whilst in those districts which are wholly destitute of lime, 
like the Lizard in Cornwall, and similar tracts of magnesian- 
silicate in Asia Mino:j?, there are no moUusca. — [Forbes.) 

The texture of shells is various and characteristic. Some, 
when broken, present a dull lustre like marble or china, and 
are tern^ed porcelj.q.nous ; others are pearly or nacreous ; some 
have a fibrous struptiu'e ; some are horny, and others glassy and 
translucent. 

The nacreous shells are formed by alternate layers of very 
thin membrane and carbonate of lime, but this alone does not 




* rig. 20. Cymba proboscidalis, Lam., from a very young specimen in the cabinet 
of Hugh Cunaing, Esq., fiiom Western Africa^ 



30 MANUAL OF THE MOLLFSCA. 

give the pearly lustre, wliicli appears to depend on minute 
undulations of the layers, represented in Fig. 23. This lustre 
has been successfully imitated on engraved steel buttons. 
Nacreous shells, when polished, form "mother of pearl;" 
when digested in weak acid they leave a membraneous residue 
which retains the original form of the shell. This is the most 
easily destructible of shell-textures, and in some geological 
formations we find only casts of the nacreous shells, whilst 
those of fibrous texture are completely preserved. 

Pearls are produced by many bivalves, especially by the 
Oriental pearl-mussel {avicula Tnargaritifera), and one of the 
British river mussels [unio margaritiferus). They are also found 
occasionally in the common oyster, in anodonta cygnea, pinna 
noMlis, mytilus eduUs, or common mussel, and in spondylus 
gmderopus. In these they are generally of a green or rose 
colour. The pearls found in area noce are violet, and in anomia 
cepa purple. They are similar in structure to the shell, and, 
like it, consist of three layers ; but what is the innermost layer 
in the shell is placed on the outside in the pearl. The iridescence 
is due to light falling upon the out- cropping edges of partially 
transparent corrugated plates. The thinner and more trans- 
parent the plates the more beautiful is the iridescent lustre ; 
and this is said to be the reason why sea pearls excel those 
obtained from fresh-water molluscs. Besides the farrows 
formed by the corrugated surface there are a number of fine 
dark lines (ttVo" inch apart), which may add to the lustrous 
effect. In some pearls these lines run from pole to pole like 
the longitudes on the globe ; in others they run in various 
directions ; and in a few the lines on the same pearl have 
different directions, so that they cross each other. The nucleus 
frequently consists of a fragment of a brownish-yellow organic 
substance, which behaves in the same way as epidermis when 
treated with certain chemical re-agents. Sand is generally said 
to be the nucleus ; but this is simply a conjecture which has 
gradually become regarded as a fact ; it is quite the exception 
for sand to be the nucleus ; as a general rule it is some organic 
substance. In some districts one kind of nucleus seems to be 
more common than another ; at least, this is how the different 
results obtained by observers in different localities may be 
explained. Filippi {SulV origine delle Perle. Translated in 
Mijller's Arcliiv. 1856) found distoma to be the nucleus in many 
cases ; Kuchenmeister found that the pearls were most abundant 
in the molluscs living in the still parts of the river Elster, where 
the water-mites {limnochares anodontce) existed most nume- 



STEUCTUEE AND PHYSIOLOGY OP THE MOLLTJSCA. 



31 



rously. The most generally prevalent nucleus appears to be 
the bodies or eggs of minute internal parasites, such as filaria, 
distoma, huchephalus, &c.* Completely spherical pearls can 
only be formed loose in the muscles, or other soft parts of the 
animal. The Chinese obtain them artificially by introducing 
into the living mussel foreign substances, such as pieces of 
mother-of-pearl fixed to wires, which thus become coated with 
a more brilliant material. 




Fig. 21. Pinna. 



Fig. 22. Terebratula. 



Fig. 23. Pearl, t 



Similar prominences and concretions — pearls which are not 
pearly — are formed inside porcellanous shells; these are as 
variable in colour as the surfaces on which they are formed. J 

The fihrous shells consist of successive layers of prismatic 
cells containing translucent carbonate of lime ; and the cells of 
each successive layer correspond, so that the shell, especially 
when very thick (as in the fossil inoceramus and trichites), will 
break up vertically into fragments, exhibiting on their edges a 
structure like arragonite, or satin-spar. Horizontal sections 
exhibit a cellular network, with here and there a dark cell, 
which is empty (Fig. 21). 

The oyster has a laminated structure, owing to the irregular 
accumulation of the cells in its successive layers, and breaks 
up into horizontal plates. 

In the boring-shells (pholadidce) the carbonate of lime has an 
atomic arrangement like arragonite, which is considerably 
harder than calcareous spar ; in other cases the difference 
in hardness depends on the proportion of animal matter and the 
manner in which the layers are aggregated. § 

* Drs. Mobius and Kelaart, Annals of Nat. Hist, i., 1858, p. 81. 

t Figs. 21, 22, 23.' gMagnified sections of shells, from Dr. Carpenter. Fragments of 
shell ground very thin, and cemented to glass slides- with Canada balsam, are easily 
prepared, and form curious microscopic objects. 

t They are pink in turbinellus and strombus; white in rstrea; white or glassy, 
purple or black, mmytilus ; rose-coloured and translucent in pinna. — ( Gray,) 

§ The specific gravity of floating shells (such as argonauta and ianthina) is lower 
than that of any others.— (Z)e la Beche.) 



32 



MANTJAL OP THE MOLLTJSCA. 



In many bivalve shells there occurs a minute tubular struc- 
ture, which is very conspicuous in some sections of pinna and 
oyster-shell. This tubular structure is frequently occasioned 
by the growth of a confervoid sponge, hence great care is 
required in determining whether the perforations are an 
essential part of the shell. 

The hrachiopoda exhibit a characteristic structure by which 
the smallest fragment of their shells may be determined ; it 
consists of elongated and curved cells matted together, and 
often perforated by circular holes, arranged in quincunx order 
(Fig. 22). 

But the most complex shell-structure is presented by the 
porcellanous gasteropoda. These consist of three strata which 
readily separate in fossil shells, on account of the removal of 

their animal cement. In Fig. 
24, a represents the outer, h 
the middle, and c the inner 
stratum ; they may be seen 
also in Fig. 25. Each of 
these three strata is com- 
posed of very numerous ver- 
tical plates, like cards placed 
on edge ; and the direction 
of the plates is sometimes 
transverse in the central 
stratum, and lengthwise in the outer and inner (as in cyprcea, 
cassis, ampullaria, and hulimus), or longitudinal in the middle 
layer and transverse in the others (e. g. comis, pyrula, oliva, and 
voluta). 

Each plate, too, is composed of a series of prismatic cells, 
arranged obliquely (45*^), and their direction being changed in 
the successive plates, they cross each other at right angles. 
Tertiary fossils best exhibit this structure, either at their broken 
edge, or in polished sections. — [Bowerhanh.)^ 

The argonaut-shell and the bone of the cuttle-fish have a 
peculiar structure ; and the Hippurite is distinguished by a 




Fig. 24. Sections of a Cone.* 



* Sections of Conus ponderosus, Bmg., from the Miocene of the Touraine. A, 
longitudinal section of a fragment ; B, complete horizontal section ; a, outer layer ; 6, 
middle ; c, inner layer ; d, e, /, lines of growth. 

t It is necessary to bear in mind that fossil shells are often pseudomorphous, or mere 
casts, in spar or chalcedony, of cavities once occupied by shells ; such are the fossils 
found at Blackdown, and many of the London clay fossils at Barton. The Palaeozoic 
fossils are often metamorphic, or have undergone a re-arrangement of their particlePi 
like the rocks in which they occur. 



BTRTTCTmiE AKD PHTSrOtOGT OP THE MOLLTTSCA. 33 

cancellated texture, unlike any other shell, except perhaps 
some of the cardiacece and chamacece. 

Epidermis. All shells have an outer coat of animal matter 
called the "epidermis" {ov periostracum), sometimes thin and 
transparent, at others thick and opaque. It is thick and olive- 
coloured in all fresh- water shells and in many arctic sea- shells 
(e. g. cyprina and astarte) ; the colours of the land-shells often 
depend on it ; sometim.es it is silky as in helix sericea, or fringed 
"with hairs as in trichotropis ; in the wholk and some species of 
triton and conus it is tjaick and rough, like coarse cloth, and in 
some modiolas it is drawn out into long beard-like filaments. 

In the cowry and other molluscs with large mantle lobes the 
epidermis is more or less covered up by an additional layer of 
shell deposited externally. 

The epidermis has life, but not sensation, like the human 
scarf-skin ; and it protects the shell against the influence of the 
weathep and chemical agents ; it soon fades or is destroyed after 
the death of the animal in situations where, whilst living, it 
would have undergone no change. In the bivalves it is 
organically connected with the margin of the mantle. 

It is most developed in shells which frequent damp situations, 
amongst decaying leg-ves, and in fresh-water shells. All fresh 
waters are more or less saturated with carbonic-acid gas, and 
in limestone conntries hold so much lime in solution as to 
deposit it in the form of tufa on the mussels and other shells.* 
But in the absence of lime to neutralise the acid the water acts 
on the shells, and would dissolve them entirely if it were not 
for their protecting epidermis. As it is, we can often recognise 
fresh-water shells by the erosion of those parts where the 
epidermis was thinnest, namely, the points of the spiral shells 
and the umbones of the bivalves, those being also the parts 
longest exposed. Specimens of melanopsis and hithynia become 
truncated again and again in the course of their growth, until 
the adults are sometimes only half the length they should be, 
and the discoidal planorhis sometimes becomes perforated by 
the removal of its inner whorls ; in these cases the animal 
closes the break in its shell with new layers. Some of the 
unios thicken their umbones enormously, and form a layer of 
animal matter with each new layer of shell, so that the river 
action is arrested at a succession of steps. 

* As at Tisbury, in Wiltshire, where remarkable specimens of anodons were 
obtained by the late Miss Benett. 



c 3 



34 



MAmiAL OF THE MOLLTTSCA. 



FORMATION AND GROWTH OF THE SHELL. 

The shell, as before stated, is formed by the mantle ; indeed, 
each layer of it was once a portion of the mantle, either in the 
form of a simple membrane or as a layer of cells ; and each 
layer was successively calcified (or hardened with carbonate of 
lime) and thrown off by the mantle to unite with those pre- 
viously formed. Being extravascular it has no inherent power 
of repair. — {Carperder.) 

■ The epidermis and cellular structures are formed by the 
margin (or collar) of the mantle ; the membranous and nacreous 
layers, by the thin and transparent portion which contains the 
viscera ; hence we find the pearly texture only as a lining 
inside the shell, as in the nautilus, and all the avicuUdce and 
turbinidcB. 

If the margin of a shell is fractured during the lifetime of 
the animal, the injury will be completely repaired by the re- 
production both of the epidermis and of the outer layer of shell 
with its proper colour. But if the apex is destroyed, or a hole 
made at a distance from the aperture, it will merely be closed 
with the material secreted by the visceral mantle. Such inroads 
are often made by boring worms and shell, and even by a sponge 
{cliona), which completely mines the most solid shells. In Dr. 
Gray's cabinet is the section of a cone, in whose apex a colony 




Fig. 25. Section of a Cone perforated by Lithodomi, 



of lithodomi had settled, compelling the animal to contract 
itself faster than it could form shell to fill up the void. 

Lines of growth. So long as the animal continues growing 
each new layer of shell extends beyond the one formed before 
it ; and, in consequence, the external surface becomes marked 
with lines of growth. During winter, or the season of rest 



STRTTCTtmE AND PHYSIOLOGY OF THE MOLLUSCA. 



35 




which corresponds to it, shells cease to grow ; and these periodic 
resting-places are often indicated by interruptions of the other- 
wise regular lines of growth and colour, or by still more obvious 
signs. It is probable that this pause, or cessation from growth, 
extends into the breeding season ; otherwise there would be 
two periods of growth and two of rest in each year. In many 
shells the growth is uniform; but in others each stage is 
finished by the development of a fringe, or ridge {varicc), or of a 
row of spines, as in tridacna and murex. — {Owen, Grant.) 

Adult characters. The attainment of the full growth proper 
to each species is usually marked 
by changes in the shell. 

Some bivalves, like the oyster 
and gryphcea (Fig. 26), continue 
to increase in thickness long after 
they have ceased to grow out- 
wards; the greatest addition is 
made to the lower valve, espe- 
cially near the umbo ; and in the 

7 7 i. i? XT. j-i Fig. 26. Section of gryphcEa* 

spondylus some parts oi the mantle ^ 

secrete more than others, so that cavities, filled with fluid, 

are left in the substance of the shell. 

The adult teredo and fistulana close the end of their burrows ; 
the pholadidea fills up the great pedal opening of its valves ; 
and the aspergillum forms the porous disc from 
which it takes its name. Sculptured shells, 
particularly ammonites, and species of rostel- 
laria and fusus, often become plain in the last 
part of their growth. But the most charac- 
teristic change is the thickening and contrac- 
tion of the aperture in the univalves. The 
young cowry (Fig. 27) has a thin, sharp lip, 
which becomes curled inwards, and enormously 

thickened and toothed in the adult ; the ptero- 

ceras (PL 4, fig. 3) develops its scorpion-like 

claws only when full-grown ; and the land- 
snails form a thickened lip, or narrow their 

aperture with projecting processes, so that it 

is a marvel how they pass in and out, and how 

they can exclude their eggs (e. g. PL 12, fig. 4, anastoma; and 

Fig. 5, helix hirsuta). 

* Fig. 26. Section of gryphcea incurva, Sby. Lias, Dorset (original; diminishecl 
one-half) ; the upper valve is not much thickened ; the interior is filled with lias. 
t Cypr/Ba testudinaria, L., young. 




Fig. 27. Young 
Cowry.t 



36 MAJ^tni. OP THE MOLLTTSCA. 

Yet at this time they would seem to require more space 
and accom.modatioii in their houses than before, and there are 
several curious ways in which this is obtained. The neritidce 
and auriculidos, dissolve all the internal spiral column * of their 
shells ; the cone (Fig. 24, B) removes all but a paper-like 
portion of its inner whorls ; the cowry goes still further, and 
continues removing the internal layers of its shell-wall, and 
depositing new layers externally with its overlapping mantle 
(Fig. 93), until, in some cases, all resemblance to the young 
shell is lost in the adult. 

The power which molluscs possess of dissolving portions of 
their own shells is also exhibited by the murices in removing 
those spines from their whorls which interfere with their growth ; 
and by the purpurce and others in wearing away the wall of 
their aperture. The agency in these cases is supposed to be 
chemical. Some support is given to this view by the composi- 
tion of the saliva of dolium galeq, (closely allied to the purpurce), 
which has been examined by Professor Troschel. A chemical 
analysis showed that it contained a minute proportion only of 
organic matter, and consisted of 94 per cent, of water, the 
remainder being almost entirely muriatic and sulphuric acids, 
and the sulphates of magnesia, potash, and soda. The secretioi; 
is apparently not used to assist digestion, since minute cal- 
careous shells were found in the stomach uninjured. It is not 
used for perforating stones ; and what its function is remains 
uncertain. We mention these facts here to show that dilute 
acids are secreted, which in some cases may be used for disr 
solving away the shell. The saliva, however, has no effect on 
the inside of the shell of the dpUum; indeed, it is said to b© 
unalterable by strong acids. {Monatsberichte der Acad^mie i^ 
Berlin, 1854, p. 486). 

Decollated shells. It frequently happens that as spiral shells 
become adult they cease to occupy the upper part of their 
cavity; the space thus vacated is sometimes filled with solid 
shell, as in magilus ; or it is partitioned off, as in vermetus^ 
euomphalus, turritella, and triton (Fig. 62). The deserted apex 
is sometimes very thin, and becoming dead and brittle, it 
breaks away, leaving the shell truncated or decollated. This 
happens constantly with the truncatellce, cylindrellce, and hulimus 
decollatus ; amongst the fresh- water shells it depends upon 
local circumstances, but is very common with pirena and 
cerithidea. 

Forms of shells. These will be described particularly under 
* This is sometimes done by the hermit-crab to the shell it occupies. 



STurcrmiE . AND jhysiologt of the mollttsca. 37: 

eacli class ; enough has been said to show that in the moliuscan 
shell (as in the vertebrate skeleton) indications are afiPorded of 
many of the leading affinities and structural peculiarities of the 
animal. It may sometimes be difficult to determine the genus 
of a shell, especially when its form is very simple ; but this 
results more from the imperfection of our technicalities and 
systems than from any want of co-ordination in the animal 
and its shell. 

Monstrosities. The whorls of spiral shells are sometimes 
separated by the interference of foreign substances, which 
adhere to them when young ; the garden-snail has been found 
in this condition, and less complete instances are comjnon 
amongst sea- shells. Discoidal shells occasionally become spiral 
(as in specimens of planorhis found at Eochdale), or irregular 
in their growth, owing to an unhealthy condition. The discoidal 
ammonites sometimes show a slight tendency to become spiral, 
and more rarely become unsymmetrical, and have the keel on 
one side instead of in the middle. 

All attached shells are liable to interference in their growth, 
and malformations consequent on their situation in cavities, or 
from coming in contact with rocks. The dreissena pplymorjoha 
distorts the other fresh- water mussels by fastening their valves 
with its hyssus ; and halani sometipies produce strange protu- 
berances on the back of the cowry, to which they have attached 
themselves when young.* 

In the miocene tertiaries of Asia Minor, Professor Forbes 
discovered whole races of neritina, paludina, and melanopsie, 
with whorls ribbed or keeled, as if through the unhealthy in- 
fluence of brackish water. The fossil periwinkles of the 
Norwich Crag are similarly distorted, probably by the access of 
fresh water; parallel cases occur at the present day in the 
Baltic. 

Reversed ^Tiells. Left-handed or reversed varieties of spiral 
shells have been met with in some of the very common species, 
like the whelk and garden-snail. Bulimus citrinus is as often 
sinistral as de?:tral ; and a reversed variety of fusus antiquus 
was more common than the normal form in the pliocene sea. 
Other shells are constantly reversed, as pyrula perversa, many 
species of pupa, and the entire genera, clausilia, physa, and 
triforis. Bivalves less distinctly exhibit variations of this 

* In the British Museum there is a heliz terrestris (Chemn.) with a small stick 
passing through it, and projecting from the apex and umbilicus. Mr. Pickering has, 
in his collection, a helix hortensis which got entangled in a nut-shell when young, and 
growing too large to escape, had to endure the incubus to the end of its days. 



36 MANUAL OF THE MOLLTJSCA. 

kind ; but the attached valve of chama has its umlo tamed to 
the right or left indifferently ; and of two specimens of lucina 
childreni in the British Museum, one has the right, the other 
the left valve flat. 

The colours of shells are usually confined to the surface beneath 
the epidermis, and are secreted by the border of the mantle, 
which often exhibits similar tints and patterns (e.g. valuta 
undulata^ Fig. 89 ). Occasionally the inner strata of porcel- 
lanous shells are differently coloured from the exterior, and the 
makers of shell -cameos avail themselves of this difference to 
produce white or rose-coloured figures on a dark ground.* 

The secretion of colour by the mantle depends greatly on the 
action of light; shallow- water shells are, as a class, warmer 
and brighter coloured than those from deep water ; and bivalves 
which are habitually fixed or stationary (like spondylus and 
pecten pleuronedes) have the upper valve richly tinted, whilst 
the lower one is colourless. The backs of most spiral shells 
are darker than the under sides ; but in ianthina the base of 
the shell is habitually turned upwards, and is deeply dyed with 
violet. Some colours are more permanent than others ; the red 
spots on the naticas and nerites are commonly preserved in 
tertiary and oolitic fossils, and even in one example (of n. sub- 
costata, Schl.) from Devonian limestone. Terehratula hastata^ 

and some pectens of the car- 

jg^ boniferous period, retain their 

^jl^^^B markings ; the orthoceras angu- 

"^Ns. /ii^«f^^^[?^Jp| liferus of the Devonian beds has 

^**'^'^PC'!*ft'^I^B 2ig-zag bands of colour ; and a 

^^;^5^^M^^^^^ terehratula of the same age, 

^^T^^^^^^^^^^ from Arctic North America, is 

* ^ r:^^^^:^^ ornamented with several rows 

of dark red spots. 
Vig,28. li'ochus.iziphinusA The operculum. Most spiral 

shells have an operculum, or lid, with which to close the aper- 
ture when they withdraw for shelter {See Qasteropoda). It is 
developed on a particular lobe at the posterior part of the foot, 



* Cameos, in the British Museum, carved on tlie shell of cassis cornuta, are white 
on an orange ground ; on c. tuberosa, and madagascariensis, white upon dark claret- 
colour ; on c. rufa, pale salmon-colour on orange ; and on strombus gigas, j'^ellow on 
pink. B}^ filing some of the olives (e.g. oliva utriculus) they may be made into very 
di^rent-coloured shells. 

t Trochus ziziphinus, from the original, taken in Pegwell Baj' abundantly. This 
species exhibits small tentacular processes, neck-lappets, side-lappets, tentacular 
filaments, and an operculigerous lobe. 



STSTTCTTTHE AND PHTSIOLOGT OP THE MOILTTSCA. 39 

and consists of horny layers, sometimes hardened with shelly 
matter (Fig. 28). 

It has been considered by Adanson, and more recently by 
Dr. Gray, as the equivalent of the dextral valve of the conchi- 
fera; but however similar in appearance, its anatomical relations 
are altogether different. In position it represents the hyseus of 
the bivalves (Loven) ; and in function it is like the plug with 
which unattached specimens of hysso-arca close their aperture. 
— {Forbes). 

homologies of the shell.* The shell is so simple a structure 
that its modifications present few points for comparison ; but 
even these are not wholly understood, or free from doubt. The 
bivalve shell may be compared to the outer tunic of the ascidian, 
cut open and converted into separable valves. In the conchifera 
this division of the mantle is vertical, and the valves are right 
and left. In the hrachiopoda the separation is horizontal, and 
the valves are dorsal and ventral. The monomyarian bivalves 
lie habitually on one side (like the pleuronectidce among fishes) ; 
and their shells, though really right and left, are termed 
"upper" and "lower" valves. The univalve shell is the 
equivalent of hoth valves of the bivalve. In the ptcropoda it 
consists of dorsal and ventral plates, comparable with the 
valves of terehratula. In the gasteropoda it is equivalent to 
both valves of the conchifera united above, f The nautilus shell 
corresponds to that of the gasteropod ; but whilst its chambers 
are shadowed forth in many spiral shells, the siphuncle is some- 
thing additional ; and the entire shell of the cuttle-fish and 
argonaut J have no known equivalent or parallel in the other 
molluscous classes. The student might imagine a resemblance 
in the shell of the orthoceras to a hack- hone. The phragmocone 
is the representative of the calcareous axis (or splanchno- skeleton) 
of a coral, such as amplexus or siphonophyllia. 

Temperature and hybernation. Observations on the tempera- 
ture of the moUusca are still wanted ; it is known, however, to 
vary with the medium in which they live, and to be sometimes 
a degree or two higher or lower than the external temperature ; 



* Parts which correspond in their real nature — (their origin and development) — 
axe temoied homologous ; those ■which agree merely in appearance, or office, are said to 
be analogous. 

t Compare fissurella or trochus (Fig. 28) with lepton squamosum (Fig. 12). The. 
disk of hipponyx is analogous to the ventral plate of hyalcea and terebratula. 

X The argonaut shell is compared by Mr. Adams to the nidamental capsules of the 
lohelk ; a better analogue would havg been found in the raft of the ianthina, which is 
secreted by the foot of the animal, and serves to /loat the egg-capsules. 



40 MANtTAL OF THE MOLltTSCA. 

witli snails (in cool weather) it is generally a degree or two 
higher. 

The moUusca of temperate and cold climates are subject to 
hylxrnation ; during which state the heart ceases to beat, 
respiration is nearly suspended, and injuries are not healed. 
They also CBstivate, or fall into a summer sleep when the heat is 
great ; but in this the animal functions are much less inter- 
rupted. — {Mailer.) 

Reproduction of lost parts. It appears from the experiments 
of Spallanzani, that snails, whose ocular tentacles have been 
destroyed, reproduce them completely in a few weeks ; others 
have repeated the trial with a like result. But there is some 
doubt whether the renewal takes place if the brain of the animal 
be removed as well as its horns. Madame Power has made 
similar observations upon various marine snails, and has found 
that portions of the foot, mantle, and tentacles, were renewed. 
Mr. Hancock states that the species of eolis are apt to make a 
meal off each other's papiUoe, and that, if confined in stale 
water, they become sickly and lose those organs ; in both cases 
they are quickly renewed under favourable circumstances. 

Viviparous reproduction. This happens in a few species of 
gasteropods, through the retention of the eggs in the oviduct, 
until the young have attained a considerable growth. It also 
appears to take place in the acephalans, because their eggs gene- 
rally remain within some part of the shell of the parent until 
hatched. 

Oviparous reproduction. The sexes are distinct in the most 
highly organised (or dioecious) moUusca ; they are united in the 
{monoecious) land-snails, pteropods, opisthobranchs, and in some 
of the conchifers. The prosobranchs pair ; but in the dioecious 
acephalans, the spermatozoa are merely discharged into the 
water, and are inhaled with the respiratory currents by the 
other sex. The monoecious land-snails require reciprocal 
union; the limneids unite in succession, forming floating 
chains. 

The eggs of the land- snails are separate, and protected by a 
shell, which is sometimes albuminous and flexible, at others 
calcareous and brittle ; those of the fresh-water species are soft, 
mucous, and transparent. The spawn of the sea-snails consists 
of large numbers of eggs, adhering together in masses, or spread 
out in the shape of a strap or ribbon, in which the eggs are 
arranged in rows ; this nidamental ribbon is sometimes coiled 
up spirally, like a watch-spring, and attached by one of its 
edges. The eggs of the carnivorous gasteropods are enclosed 




STEXJCTUEE AND PHYSIOLOGY OF THE MOLLTJSCA. 41 

in tough albuminous capsules, each containing numerous germs ; 
these are deposited singly, or in rows, or agglutinated in groups, 
equalling the parent ani- 
mal in bulk (Fig. 83). The 
nidamental capsules of the 
cuttle-fish are clustered 
like grapes, each con- 
taining but one embryo; 
those of the calamary are 
grouped in radiating 
masses, each elongated 
capsule containing 30 or 
40 ova. The material, 
with which the eggs are 
thus cemented together, or ^. „„ ^ . ^ ^ . ^ 

, , . * , , 1 Fig. 29. Smwh of Doris.* 

enveloped, is secreted by 

the nidamental gland, an organ largely developed in the female 

gasteropods and cephalopods (Fig. 50, n). 

Development. The molluscan ovum consists of a coloured 
yolk {yitellus), surrounded by albumen. On one side of the 
yolk is a pellucid spot, termed the germinal vesicle, having a 
spot . or nucleus on its surface. This germinal vesicle is a 
nucleated cell, capable of producing other cells like itself ; it is 
the essential part of the B^g, from which the emhryo is formed ; 
but it undergoes no change without the influence of the sperma- 
tozoa.-\ After impregnation, the germinal vesicle, which then 
subsides into the centre of the yolk, divides spontaneously into 
two ; and these again divide and subdivide into smaller and still 
smaller globules, each with its pellucid centre or nucleus, until 
the whole presents a uniform granular appearance. The next 
step is the formation of a ciliated epithelium on the surface of 
the embryonic mass ; movements in the albumen become per- 
ceptible in the vicinity of the cilia, and they increase in strength, 
until the embryo begins to revolve in the surrounding fluid. t 

* Nidamental ribbon of Doris Johnstoni. (Alder and Hancock.) 
t No instance of " partheno-genesis " is known among the mollusca; the most 
"equivocal" case on record is that related by Mr. Gaskoin. A specimen of helix 
lactea. Mull., from the South of Europe, after being hvo years in his cabinet, was dis- 
covered to be still living ; and on being removed to a plant-case it revived, and six 
weeks afterwards had produced twenty young ones ! 

t According to the observations of Professor Loven (on certain bivalve moUusca), 
the ova are excluded immediately after the inhalation of the spermatozoa, and 
apparently from their iniluence ; but impregnation does not take place within the 
ovary itself. The spermatozoa of cardium pygmceum were distinctly seen to pen'^trate 
in succession th,e outer envelopes pf the ova, and arrive at the vitellns, whei^ they dis- 
appeared. With respect to the "germinal vesiclp;" according to Barry, it first 



42 MAI^-TJAL OF THE MOLLTJSCA. 

Up to tHs point nearly the same appearances are presented 
by the eggs of all classes of animals, — they manifest, so far, a 
complete " unity of organisation." In the next stage, the 
development of an organ, fringed with stronger cilia, and serv- 
ing both for locomotion and respiration, shows that the embryo 
is a molluscous animal ; and the changes which follow soon point 
out the particular class to which it belongs. The rudimentary 
head is early distinguishable by the black eye-specks ; and the 
heart by its pulsations. The digestive and other organs are 
first "sketched out," then become more distinct, and are seen 
to be covered with a transparent shell. By this time the em- 
bryo is able to move by its own muscular contractions, and to 
swallow food; it is therefore "hatched," or escapes from the 

Yery little is known respecting the development of Brachio- 
pods. P. Miiller has described * an embryo which, it is thought, 
may belong to Crania. It possessed two roundish valves of un- 
equal size, the dorsal being the larger. At the part where the 
hinge is placed in the adult was a small oval plate. Five pairs 
of stiff setae projected from the mantle, and four of them origi- 
nated from the ventral half. The edge of the mantle in the dorsal 
valve was beset with numerous finer setae, which curved over 
upon the outside of the ventral valve. The alimentary canal 
filled the posterior half of the space between the valves. There 
■were two auditory capsules and two eyes. The anterior half was 
occupied by four pairs of cylindrical arms, surrounding a round 
knob, at the summit of which was the mouth. Locomotion 
was effected by means of the cilia enveloping the arms, which 
impelled the animal through the water with the mouth fore- 
most. No circulatory or reproductive organs could be detected. 

The young bivalves are hatched before they leave their parent. 
[See page -393) The forms they pass through present distinct 
differences in several families, so that even in the present state of 
embryological knowledge, some five or six types of development 
are known. Even in the same family there may be a great dis- 

approaches the inner surface of the vitelline ' membrane, in order to receive the 
influence of the spermatozoa ; it then retires to the centre of the yolk, and undergoes 
a series of spontaneous subdivisions. In M. Loven's account it is said to "burst" and 
partially dissolve, whilst the egg remains in the ovary, and before impregnation ; it 
then passes to the centre of the yolk, and undergoes the changes described by Barry, 
along with the yolk, whilst the nucleus of the germinal vesicle, or some body exactly 
resenabling it, is seen occupying a small prominence on the surface of the viteUine 
membrane, until the metamorphosis of the yolk is completed, when it disappears, in 
Bome unobserved manner, without fulfilling any recognised purpose. 

* Archiv fur Anatomic unci Physiologic, 1860, p. 72 ; see also Annals of Nat. Hist 
for 1860. 



STRrCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 



43 



similarity, as in tlie case of the marine and fresh,- water forms 
of the mytilidse. The following account refers to the type to 
which the young of Crenella belong. At first they have a 
swimming disk, fringed with long cilia, and armed with a slen- 
der tentacular filament [flagellum). At a later period this disk 
disappears progressively as the labial palpi are ^l 
developed ; and they acquire a foot, and with it 
the power of spinning a byssus. They now have 
a pair of eyes situated near the labial tentacles 
(Fig. 30* e), which are lost at a further stage, or 
replaced by numerous rudimentary organs placed 
more favourably for vision, on the border of the 
mantle. The development of the young has 
been noticed in many of the genera of Pteropods. 
They are divisible into two groups : those in 
which the body is surrounded with one or more rings of cilia, 
and those in which these rings are absent. 

n 7> 





Fig. 30*. Fry of the Mussel.t 

Most of the aquatic gasteropoda are very minute when 

* Fig. 30. Very young fry of crenella marmorata, Forbes, highly magnified; 
d, disk, bordered with cilia ; /, flagellum ; v v, valves ; m, cUiated mantle, 
t Fig. 30*. Fry of mytilus edulis, after Loveu. e, eye ; e\ auditory capsule ; I t. 



44 



MANUAL OF THE MOLLUSCA. 




hatclied, and they enter life under the same form, — that which 
has been already referred to as permanently characteristic of 
the pteropoda. (Fig. 69.) 

The Pulmom'fera and Cepha'cpoda produce large eggs, con^ 
taining sufficient nutriment to support the embryo until it has 
attained considerable size and development ; thus, the newly- 
born cuttle-fish has a shell half an inch 
long, consisting of several layers, and the 
buUmus ovatus has a shell an inch in 
length when hatched. (Fig. 31.) These 
are said to undergo no transformation, 
because their larval stage is concealed in 
the egg. 

The researches of JoJm Hunter i into 

the embryonic condition of animals, led 

him to the conclusion that each stage in 

the development of the highest animals 

^ corresponded to the permanent form of 

some one of the inferior orders. This 

grand generalisation has since been more exactly defined and 

established by a larger induction of facts, some of which we 

have already described, and may now be stated thus : — 

In the earliest period of existence all animals display one 
uniform condition ; but after the first appearance of special 
development, uniformity is only met with amongst the mem- 
bers of the same primary division, and with each succeeding 
step it is more and more restricted. Prom that first step, the 
members of each primary group assume forms and pass through 
phases which have no parallels, except in the division to which 
each belongs. The mammal exhibits no likeness, at any period, 
to the adult mollusc, the insect, or the star-fish ; but only to 
the ovarian stage of the invertebrata, and to more advanced 
stages of the classes formed upon its own type. And so also 
with the highest organised moUusca ; after their first stage they 



labial tentacles ; s s', the stomach ; S, branchiae ; h, heart ; v, vent ; I, liver ; r, renal 
organ ; a, anterior adductor; a', posterior adductor ; /, foot. The arrows indicate the 
incurrent and excurrent openings ; between wliich the margins of the mantle are 
united in the fry. 

* Egg and young of bulimus ovatus, Miill, sp., Brazil, from specimens in the collec- 
tion of Hugh Cuming, Esq. 

t " In his printed works the finest elements of system seem evermore to flit before 
him, tvrice or thrice only to have been seized, and after a momentary detention to 
have been again suffered to escape. At length, in the astonishing preparations for his 
museum, he constructed it, for the scientific apprehension, out of the unspokca 
Alphabet of nature." — Coleridge. 



OLASSinCATIOJr. 4^ 

resemble tHe simpler orders of their own sub-kingdom, but not 
those of any other group. 

These are the yiews of Professor Owen — the successor of 
Hunter — by whom it has been most clearly shown and stead- 
fastly maintained, that the * ' unity of organisation " manifested 
by the animal world results from the design of a Supreme In- 
telligence, and cannot be ascribed to the operation of a mechani- 
cal " law." 

CLASSIPICATION. 

The objects of classification are, first, the convenient and in- 
telligible arrangement of the species ; * and, secondly, to afibrd 
a summary, or condensed exposition, of all that is known re- 
specting their structure and relations. 

In studying the shell-fish we find resemblances of two kinds. 
First, agreements of structure, form, and habits ; and, secondly, 
resemblances of form and habits without agreement of struc- 
ture. The first are termed relations of affinity ; the second, of 
analogy. 

Affinities may be near, or remote. There is some amount of 
ajGfinity common to all animals ; but, like relationships amongst 
men, they are recognised only when tolerably close. Besem- 
blances of structure which subsist from a very early age are 
presumed to imply original relationship ; they have been termed 
genetic (or histological), and are of the highest importance. Those 
which are superinduced at a later period are of less consequence. 

Analogies. Modifications relating only to peculiar habits are 
called adaptive; or teleological, from their relation to final 
causes. t A second class of analogical resemblances are purely 
external and illusive ; they have been termed mimetic {Strick- 
land), and, by their frequency, almost justify the notion that a 
certain set of forms and colours are repeated, or represented in 
every class and family. In all artificial arrangements, these 
mimetic resemblances have led to the association of widely dif- 
ferent animals in the same groups. J Particular forms are also 
represented geographically§ and geologically,]] as well as sys- 
tematically. 

* At least 20,000 recent, and 16,000 fossil species of molluscous animals are known. 

t For example, the paper nautilus, from its resemblance to carinaria, was long sup- 
posed to be the shell of a nucleobranch, parasitically occupied by the ^^ ocythoe.^^ 

t e. g. Aporrhdis with strombus, and ancylus vrAxfatella. 

% Monoceros imbricatum and buccinum antarcticum take the place, in South 
America, of our conomon whelk and purple, and solen gladiolus and solen americanus 
of our solen siliqua and ensis. 

\ The frequent recurrence of similar species in successive strata may lead beginners 
to attribute too much to the influence of time and external- circumstances ; but such 
impressions disappear with further experience. 



46 MANUAL OP THE MOLLUSCA. 

In all attempts to characterise groups of animals, we find- 
that in advancing from the smaller to the larger combinations, 
many of the most obvious external features become of less avail, 
and we are compelled to seek for more constant and comprehen- 
sive signs in the phases of embryonic development, and the 
condition of the circulating, respiratory, and nervous systems. 

Species. All the specimens, or individuals, which are so 
much alike that we may reasonably believe them to have 
descended from a common stock, constitute a species. It is a 
particular provision for preventing the blending of species, that 
hybrids are always barren ; and it is certain, in the case of shells, 
that a great many kinds have not changed in form from the 
tertiary period to the present day, — a lapse of many thousand 
years, — and through countless generations. When individuals 
of the same brood differ in any respect, they are termed varieties ; 
for example, one may be more exposed to the light, and become 
brighter coloured; or it may find more abundant food, and 
grow larger than the rest. Should these peculiarities become 
permanent at any place or period, — should all the specimens on 
a particular island or mountain, or in one sea, or geological 
formation, differ from those found elsewhere, — such permanent 
variety is termed a race ; just as in the human species there aro 
white and coloured races. The species of some genera are less 
subject to variation than others ; the nuculce, for example, 
although very numerous, are always distinguishable by good 
characters. Other genera, like ammonites, terehratula, and tel- 
lina, present a most perplexing amount of variation, resulting 
from age, sex, supply of food, variety of depth, and of saltness 
in the water. And further, whilst in some genera every pos- 
sible variety of form seems to have been called into existence, in 
others only a few, strikingly distinct forms, are known. 

Genera are groups of species, related by community of struc- 
ture in all essential respects. The genera of bivalves have been 
characterised by the number and position of their hinge teeth ; 
those of the spiral univalves, by the foim of their apertures; 
but these technical characters are only valuable so far as they 
indicate differences in the animals themselves. 

Families are groups of genera, which agree in some more 
general characters than those which unite species into genera. 
Those which we have employed are mostly modifications of the 
artificial families framed by Lamarck, a plan which seemed 
more desirable, in the present state of our knowledge, than a 
subdivision into very numerotis families, without assignable, 
characters. 



CLASSrPICATIOW. 47 

The orders and classes of moUusca have already been referred 
to ; those now in use are in most cases natural. 

It has been sometimes asserted that these groups are only 
scientific contrivances, and do not really exist in nature Jbut 
this is a false as well as a degrading view of the matter. The 
labours of the most eminent systematists have been directed to 
the discovery of the subordinate value of the characters deriv- 
able from every part of the animal organisation ; and, as far as 
their information enabled them, they have made their systems 
expressive "of all the highest facts or generalisations in 
natural history." — (^Owen.) 

M. Milne Edwards has remarked, that the actual appearance 
of the animal kingdom is not like a well-regulated army, but 
like the starry heavens, over which constellations of various 
magnitude are scattered, with here and there a solitary star 
which cannot be included in any neighbouring group. 

This is exceedingly true ; we cannot expect our systematic 
groups to have equal numerical values,* but they ought to be 
of equal structural importance ; and they will thus possess a 
symmetry of order, which is superior to mere numerical regu- 
larity. 

All the most philosophic naturalists have entertained a belief 
that the development of animal forms has proceeded upon som^ 
regular plan, and have directed their researches to the discovery 
of that "reflection of the Divine mind." Some have fancied 
that they have discovered it in a mystic number, and have ac- 
cordingly converted all the groups into fivesA We do not 
undervalue these speculations, yet we think it better to describe 
things so far only as we know them. 

Great difficulty has always been found in placing ' groups 
according to their affinities. This cannot be efiected in — the 
way in which we are compelled to describe them — a single 
series ; for each group is related to all the rest ; and if we 
extend the representation of the affijiities to very small groups, 
any arrangement on a plane surface would fail, for the 
affinities radiate in all directions, and the " network" to which 
Fabricius likened them, is as insufficient a comparison as the 
" chain" of older writers. J 

* The numerical development of groups is inversely proportional to the bulk of the 
iudividuals composing them. — {Waterhouse.') 

t The quinarians make out five molluscous classes by excluding the tunicata ; the 
same end would be attained in a more satisfactory manner by reducing the ptercpoda 
to the rank of an order, which might be placed next to the opistho-branchs. 

X The quinary arrangement of the molluscous classes reminds us of the eastern 



48 MANUAL OF THE MOLLTJSCA. 

NOMENCLATURE. 

The practice of using two names — generic and specific — ^for 
eacli animal, or plant, originated with Linnaeus ; therefore no 
scientific names date further back than his works. In the con- 
struction of these names the Greek and Latin languages are 
preferred by the common consent of all countries. 

Synonyms. It often happens that a species is named, or a 
genus established, by more than one person, at different times, 
and in ignorance of each other's labours. Such duplicate names 
are called synonyms ; they have multiplied amazingly of late, 
and are a stumbling-block and an opprobrium in all branches 
of natural history.* 

One very common estuary shell rejoices in the following 
Tariety of titles : — 

Scrobicularia piperata [Gmelin sp.), 

Trigonella plana [Da Costa). 

Mactra Listeri [Auct.). 

Mya Hispanica {Chemnitz). 

Venus borealis [Pennant). 

Lutraria compressa [Lamarck). 

Arenaria plana [Megerle). 
As regards specific names, the earliest ought certainly to be 
adopted, with, however, the following exceptions : — 

1. MS. names ; which are admitted by courtesy. 

2. Names given by writers antecedent to Linnaeus. 

3. Names unaccompanied by a description or figure. 

4. Barbarisms ; or names involving error or absurdity, f 

It is also very desirable that names having a general (Euro- 
pean) acceptation should not be changed on the discovery of 
earlier names in obscure publications. 

emblem of eternity — tlie serpent holding its tail in its mouth. The following diagram 
is offered as an improved circular system : — 

[Fishes.] 
Di-branchiata. 

Nucleo- V ., Tetra- 



Opistho- ^ 


<,^^^ Proso- 


Aporo- 


^1 Puhno- 


Pallio- 


Lamelli- 



Hetero-branchiata. 
[Zoophytes.] 
* In Pfeiffe^'s Monograph of the HelicicUe, a family containing seventeen genera, 
no less than 330 generic synonyms are enumerated ; to this list Dr. Albers, of Berlin, 
has added another hundred of his ovm invention ! 

t This subject vraa investigated and reported upon by a committee of the British 
Association in 1842. 



ABBHEVIATIOKS. 49 

With respect to genera^ those who believe in their real exist- 
ence as " ideas of the creating mind," will be disposed to set 
aside many random appellations given to particular shells 
without any clear enunciation of their characters ; and to adopt 
later names, if bestowed with an accurate perception of the 
grounds which entitle them to generic distinction.* 

Authority for specific names. The multiplication of synonyms 
having made it desirable to place the authority after each name, 
another source of evil has arisen ; for several naturalists (fancy- 
ing that the genus maker, and not the species maker, should 
enjoy this privilege) have altered or divided almost every genus, 
and placed their signatures as authorities for names given half 
a century or a century before by Linnaeus or Bruguiere. The 
majority of naturalists have disowned this practice, and agreed 
to distinguish by the addition of "sp." the authorities for 
those specific names whose generic appellations have been 
altered. The type of a genus should be the species which best 
exhibits the characters of the group, but it is not always easy 
to follow out this rule ; and consequently the first on the list is 
often put forward as the type. 

ABBREYIATIOK'S. 

Etym., etymology; Syn., synomym; Distr., distribution; 
MS., unpublished ; Sp., species ; B. M., in the British Museum. 

Distr., Norway — ^New Zealand; including all intermediate 
seas. 

Foss., Lias- chalk : implies that the genus existed in these 
and all intermediate strata. Chalk — ; means that the genus has 
existed from the chalk up to the present time. 

Depth — 50 fms. implies that the genus is found at all depths 
between low- water mark and 50 fathoms. A fathom = 6 feet. 
"I", one-fourth real size ; f, magnified four times. 

Lat., breadth; Long., length; Alt., height or thickness. 
Unc. , an inch ; Lin. , a line or -^^ of an inch ; Mill. , a milli- 
metre or -^ of an inch. 

* Several bad practices — against which there is, unhappily, no law — should be 
Strongly discountenanced. First, tlie employment of names already in famUiar use 
for other objects ; such as cidaris (the title of a well-known genus of sea-urchins) for 
a group of spiral shells; and arenaria (a property of the botanists) for a bivalve. 
Secondly, the conversion of specific into generic titles, a process which has caused 
endless confusion ; it has arisen out of the vain desu-e of giving new desigtations to 
old and familiar objects, and thus obtaining a questionable sort of fame. 



50 MANUAL OF THE MOLLFSCA. 

CHAPTEE II. 

GEOGRAPHICAL DISTRIBITTION OF THE MOLLTJSCA. 

It is one of the most familiar facts in Natural History that 
many countries possess a distinct Fauna and Flora, or assem- 
blages of animals and plants peculiar to themselves ; and it is 
equally true, though less generally understood, that the sea 
also has its provinces of animal and vegetable life. 

The most important or best known of these provinces are 
indicated on the accompanying map ; different names, in some 
instances, and different letters and numbers, being employed to 
distinguish the marine from the terrestrial regions.* 

The division of the surface of the globe into natural history 
provinces ought to be framed upon the widest possible basis. 
The geographical distribution of every class of animals and 
plants should be considered in order to arrive at a theory of 
universal application. 

The most philosophical division of the globe into natural 
provinces has been by Swainson in 1835, and by Dr. Sclater in 
185Y. The last has been adopted by several naturalists. It was 
based upon a consideration of the distribution of birds, and has 
been extended to fishes and amphibia by Dr. Gunther. It 
might be extended to moUusca. In Dr. Sclater' s scheme the 
world is divided into six regions, viz. (1) Paleearctic region: 
this comprises Europe, North Africa, Asia Minor, Persia, Asia 
north of the Himalayas, North China, and Japan ; (2) Ethiopian 
or Western Palseotropical region, includes Africa south of the 
Atlas, Madagascar, Mascarene, Arabia ; (3) Indian or Middle 
Palseotropical region, including Asia south of the Himalayas, 
Ceylon, Burmah, Malacca, Southern China, Philippines, Borneo, 
Java, Sumatra, and adjacent islands; (4) Australian or Western 
Palseotropical region : Australia, New Guinea, New Zealand, 
and the Pacific Islands ; (5) Nearctic or North American region : 
Greenland, and North America as far as the centre of Mexico ; 

* The author regrets that, on account of the expense, this map appears without the 
advantage of colours. He would reconamend those who are sufficiently interested in 
the subject to colour their own copies, distinguishing the shores of the marine provinces 
by the following tints : — 

Blue. 1. Arctic province ; 15. Magellanic. 

Green. 2. Boreal; 11. Aleutian; 6. Aralo-Caspian. 

Orange. 3. Celtic. 

Purple. 4. Lusitanian ; 10. Japonic ; 12. Califomian ; 18. Trans- Atlantic. 

Yellow. 6. W. African; 8. Indo-Pacific ; 13. Panamic; 17. Caribbean. 

Lake, 1. S.African; 9. Australo-Zealandic ; 14. Peruvian; 16. Patagonian. 



T^ 




GEOGBAPHICAL DISTRIBUTIOX. 51 

(6) Neotropical or South American region : "West India Islands, 
South Mexico, Central and South America, Galapagos, and 
Falkland Isles. These divisions apply to the land, but it is 
probable that they will help to throw light on the boundaries of 
the natural marine provinces. 

As will be seen, each of the above regions includes several of 
the provinces adopted in this work. 

The Land Provinces hitherto proposed have been chiefly 
founded on botanical grounds, but the evidence afforded by 
insects and the higher classes of animals confirms the existence 
of these divisions. 

The Marine Provhices have also been investigated by botanists ; 
and the striking peculiarities of the fisheries have been taken 
into account as well as the distribution of shell-fish and corals. 

In order to constitute a distinct province it is considered 
necessary that at least one-half the species -should be peculiar, a 
rule which applies equally to plants and animals. Some genera 
and sub-genera are limited to each province, but the proportion 
is different in each class of animals and in plants.* 

Specific areas. Species vary extremely in their range, some 
being. limited to small areas, while others, more widely diffased, 
unite the local populations into fewer and larger groups. 
Those species which characterise particular regions are termed 
"endemic;" they mostly require peculiar circumstances, or 
possess small means of migrating. The others, sometimes 
called '* sporadic," possess great facilities for diffusion, like the 
lower orders of plants propagated by spores, and more easily 
meet with suitable conditions. The space over which a species 
is distributed is called a " centre," or, more properly, a specific 
area. The areas of one-half the species are smaller (usually 
much smaller) than a single province. 

In each specific area there is frequently one spot' where indi- 
viduals are more abundant than elsewhere ; this has been called 
the " metropolis " of the species. Some species which appear to 
be nowhere common can be shown to have abounded formerly ; 
and many probably seem rare only because their head-quarters 
are at present unknown. — {Forbes.) 

Specific centres are the points at which the particular species 
are supposed to have been created, according to those who 
believe that each has originated from a common stock (p. 46) ; 

* The genera of plants amount to 20,000, and consist on an average of only four 
species apiece ! The genera of sheUs commonly admitted are only 400 in number, and 
average forty species each. It follows that the areas of the molluscaa genera {cceterie 
paribus) ought to be ten times as great as" those of plants. 



52 MANUAL OF THE MOLLTTSCA, 

these can " only be known approximately in any case. The 
doctrine that each species originated from a single individual, 
or pair, created once only, and at one place, derives strong con- 
firmation from the fact that so ' ' many animals and plants are 
indigenous only in determinate spots, while a thousand others 
might have supported them as well."* 

Generic areas. Natural groups of species, whether called 
genera, families, or orders, are distributed much in the same 
manner as species ; f not for the same reason, since their con- 
stituents are not related by descent, but apparently from the 
intention of the Creator. 

Sub-generic areas are usually smaller than generic ; and the 
areas of orders and families are, as a matter of course, larger 
than those of the included genera. But it is necessary to 
remember that groups of the same denomination are not always 
of equal value ; and since species vary in range it often happens 
that specific areas of one class or family are larger than generic 
areas of another. The smallest areas are usually those of the 
forms termed aberrant ; the typical groups and species are 
most widely distributed. — [Waterhouse.) 

"When a generic area includes a considerable number of 
species, there may be found within it a point of maximum 
(metropolis), around which the number of species becomes less 
and less. A genus may have more centres than one. It may 
have had unbroken extension at one period, and yet in the 
course of time and change, may have its centre so broken up 

* Mrs. Somerville's Physical Geography, ii. 95. 

t " What we call class, order, family, genus, are all only so many names for genera 
of various degrees of extent. Technically a genus is a group to -which a name (as 
liibes) is applied : but essentially, Exoyens, RanunculacecB, Banunculus, are genera of 
different degrees. 

" One of the chief arguments in favour of the naturalness of genera (or groups), la 
that derived from the fact that many genera can be shovyn to be centralised in definite 
geographical areas {Erica, for example) ; i.e. we find the species gathered all, or 
mostly, within an area, which has some one point where tlie maximum, number of 
species is developed. 

" But, in geographical space, we not unfrequently find that the same genus may have 
two or more areas, within each of which this phenomenon of a point of maximum 
number of species is seen, with fewer and fewer species radiating, as it were, from it. 

" In time, however (or, in other words, in geological distribution), so far as we know, 
each generic type has had an unique and continuous range. When once a generic 
type has ceased it never re- appears. 

" A genus is an abstraction, a divine idea. The very fact of the centralisation of 
groups of allied species, i.e. of genera, in space and time, is sufficient proof of this. 
Doubtless we make many so-called genera that are artificial ; but a true genus is 
natui'al; and, as such, is not dependent on man's will." — E. Forbes. (See An. Nat. 
Hist. July, 1852, and Jan., 1856, p. .45.) 



GEOGEAPHICAL DISTRIBUTION. 53 

that there shall appear to be out-lying points. When, how- 
ever, the history of a natural genus shall have been traced 
equally through its extension in time and space, it is not 
impossible that the area, considered in the abstract, will be 
found to be necessarily unique." — {Forbes.) 

To illustrate the doctrine of the unity of generic areas Professor 

Forbes has given several examples, showing that some of the 

most exceptional cases admit of explanation and confirm the 

rule. One of these relates to the genus Mitra, of which there 

are 420 species ; it has its metropolis in the Philippine Islands, 

I and extends by the Eed Sea to the Mediterranean and West 

(Africa, the species becoming few, small, and obscure. Far 

away from the rest a single species is found on the coast of 

Greenland. But this very shell occurs fossil in Ireland along 

with another mitra now living in the Mediterranean. Another 

case is presented by the genus Fanopcea, of which the eleven 

' living species are widely separated. Of this genus above 100 

fossil species are known, distributed over many places within 

, the wide area, on whose margin the relics of this ancient form 

' of life seem to linger like the last ripple of a cii'cling wave.* 

,. According to this view the specific centres are scattered 

thickly over the whole surface of the globe ; those of the genera 

more thinly distributed ; and the points of origin of the large 

groups become fewer in succession, until we have to estimate 

the probable position or scene of creation of the primary 

divisions themselves ; and are led to speculate whether there 

may not have been some common focus — the centre of centres 

— ^from which the first and greatest types of life have emanated. 

Boundaries of Natural History Frovinces. The land provinces 

are separated by lofty mountains, deserts, seas, and climates ; 

whilst the seas are divided by continents and influenced by the 

physical character of coast-lines, by climates and currents. 

These "natural barriers," as they were called by Buffon, 

retard or altogether prevent the migrations of species in 

particular directions. 

Influence of Climate. Diversity of climate has been the 
popular explanation of most of the phenomena of geographical 
distribution, because it is so well known that some species 
require a tropical amount of warmth, whilst others can endure 
a great variety of temperature, and some only thrive amidst 
the rigours of the arctic regions. The character of the vegeta- 
tion of the zones of latitude has been sketched by Baron Hum- 

* Tlie most sfriking and conclusive instances may be met with in the distribution ol 
the highest classes of vertebrate animals. 



54 MAIOJAL OF THE MOLLUSCA. 

boldt ; FaLricius and Latreille have divided the world into > 
climatal Insect-provinces ; and Professor E. Forbes has con- 
stmcted a map of the homoiozoic helts or zones of marine life. 
To all these the remark of Mr. Kirby is applicable — that any 
division of the globe into provinces, by means of equivalent 
parallels and meridians, wears the appearance of an artificial 
and arbitrary system, rather than of one according to nature. 
Professor Forbes has been careful to point out that although 
the V Faunas of regions under similar physical conditions bear 
a striking resemblance to each other" — this resemblance is 
produced, ' ' not by identity of species, or even of genera, but 
by representation " (p. 45). 

Origin of the Natural History Provinces. Mr. Kirby appears 
to have been the first to recognise the truth that physical 
conditions were not the primary causes of the zoological pro- 
vinces, which he ' ' regarded as fixed by the will of the Creator, 
rather than as regulated by isothermal lines." * Mr. Swainson 
also has shown that the ' ' circumstances connected with tem- 
perature, food, situation, and foes, are totally insufficient to 
account for the phenomena of animal geography," which he 
attributes to the operation of unknown laws.f 

The most important contribution towards a knowledge of 
these " unknown laws " has been made by Professor E. Forbes, 
who was perhaps the first naturalist ever in a position to avail 
himself of the great storehouse of facts accumulated by geolo- 
gists, respecting the distribution of organic life in ' ' the former 
world." This subject will be referred to again in connection 
with the subject of Fossil Shells ; meanwhile it may be stated 
that, according to this evidence, the Faunas of the Provinces 
are of various ages, and that their origin is connected with 
former (often very remote) geological changes, and a difierent 
distribution of land and water over the surface of the globe. 



MAEINE PHOYINCES. 

Amongst the genera of marine shells there are some which 
have been considered particularly indicative of climate. From 
the Arctic list the following may be taken as examples of the 
shells of high latitudes ; those marked * being found in the 
southern as well as in the northern hemisphere : — 

• Introduction to Entomologj'. 

t Treatise on Geography and Classification of Animals, Lardner's Cabinet Cyclo* 
psedia. 



MAEINE PROVIITCES. 55 



Buccinum. 




Velutina. 


*Crenella. 


*Chrysodomu3 


. 


Lacuna. 


*Yoldia. 


*Trophon. 




^Margarita. 


*Astarte. 


Admete. 






C}T)rina. 


*Triohotropis. 




*Khj-nchonella. 


Glycimeria. 


Tlie following 


have been thought peculiar 


to the warmer re- 


gions of the sea : 








Nautilus. 


Conus. 


Columbella. 


Perna. 


Eostellaria. 


Harpa. 


Cypreea. 


"Vulsella. 


Triton. 


Oliva. 


Nerita. 


Tridacna. 


Cancellaria. 


Voluta. 


Spondylus. 


Crassatella. 


Terebra. 


Marginella. Plicatula. 


Sanguinolara, 



But it must not be inferred that these genera were always 
characteristic of extreme climates. On the contrary, the whole 
of them have existed in the British seas at no very remote geo- 
logical period. Rhynchonella and Astarte were formerly " tropi- 
cal shells ;" and since the period of the English chalk-formation 
there have been living Nautili in the North Sea, and Cones and 
Olives in the " London basin." It is not true that the same 
species have been at one time tropical, at another temperate, but 
the genera have in many instances enjoyed a much wider range 
than, they exhibit now. ■ Some of the "tropical" forms are 
more abundant and extend farther in the Southern hemisphere ; 
several large Yolutes range to the extremity of South America, 
and the largest of all inhabits New Zealand. 

The tropical and sub-tropical provinces might be naturally 
grouped in three principal divisions, viz., the Atlantic, the 
Indo-Pacific, and the West-American, — divisions which are 
bounded by meridians of longitude, not by parallels of latitude. 
Th(i Arctic province is comparatively small and exceptional ; 
and the three most southern Paunas of America, Africa, and 
Australia differ extremely, but not on account of climate. 

If only a small extent of sea-coast is examined, the character 
of its mollusca will be found to depend very much upon the 
nature of the shore, the tides, depth, and local circumstances, 
which will be referred to again in, another page. But these 
peculiarities will disappear when the survey is extended to a 
region sufficiently large to include every ordinary variety of 
condition. 

It has been stated that each Fauna consists of a number ot 
peculiar species, properly, more than half ; ' and of a smaller 
number which are common to some'other provinces. By ascer- 
taining the direction of the tides and currents, and the circum- 
stances under which the species occur, it may be possible to 
determine to which province these more widely diffused mollusca 



56 MAlSrUAL OF THE MOLLUSCA. 

originally belonged. And when species occur both recent and 
fossil it is easy to perceive the direction in -which their migra- 
tions have taken place. 

The Fauna of the Mediterranean has been critically examined 
by Prof. Porbes and M. Phiiippi, with this result, — that a large 
proportion of its population has migrated into it from the At 
lantic, and a smaller number from the Eed Sea, and that the 
supposed peculiar species are diminishing so rapidly with every 
new research in the Atlantic, that it can no longer rank as a 
province distinct from the Lusitanian. 

When the Faunas of the other regions have been tested in 
the same manner, and disentangled, the result will probably be 
the establishment of a much greater number of provinces than 
we have ventured at present to indicate on the map. 

It may be desirable to notice here the extraordinary range 
attributed to some of the marine species. These statements 
must be received with great hesitation; for when suflB.ciently 
investigated, it has usually proved that some of the localities 
were false, or that more than one species was included. The 
following are given by Dr. Ejrauss in his excellent monograph 
of the South African MoUusca : — 

BaneUa granifera : Eed Sea, Natal, India, China, Philippines, 
New Zealand. 

Triton olearius : Brazil, Mediterranean, Natal, Pacific. 
Purpura lapillus : Greenland, (Senegal, Cape). 
Venus verrucosa : (W. Indies), Brit. Senegal, Canaries, 
Mediterranean, Red Sea, Cape (Australia). 

Octopus vulgaris : Antilles, Brazil, Europe, Natal, Mauritius, 
India. 

Argonauta argo : (Antilles), Medit., Eed Sea, Cape. 
Lucina divaricata is said to be " found on the shores of Europe, 
India, Africa, America, and Australia." {Gray.) In this case 
several species are confounded. The rock-boring Baxicava has 
been carried to all parts of the world in hallast, and it remains 
yet to be ascertained whether the same species occurs in a living 
state beyond the Arctic Seas and North Atlantic. 

Lastly, the money cowry is always catalogued as a shell of the 
Mediterranean and Cape, although its home is in the Pacific, 
and it has no other origin in the Atlantic than the occasional 
wreck of one of the ships in which such vast quantities of the 
little shell are annually brought to this country to be exported 
again to Africa. 



AECTIC PEOYHS'CE. 57 

I. Abctic Provhtoe. 

The NortL. Polar Seas contain but one assemblage of MoUusca, 
•whose Southern limit is formed by the Aleutian Islands in the 
Pacific, but in the North Atlantic is determined chiefly by the 
boundary of floating ice, descending as low as Newfoundland 
on the West, and thence rising rapidly to Iceland and the North 
Cape. A very complete general account of the Arctic Mollusca 
is given by Dr. Middendorff ; * those of Greenland have been 
catalogued and described by Otho Fabricius and Moller ;t and 
more recently by Morch •,% 158 species are enumerated by 
Middendorff, and 202 by Morch. Scattered notices occur in 
the Annals of Natural History, § and the Supplements to the 
Narratives of the Arctic Voyagers, — Phipps, Scoresby, Franklin, 
Back, Ross, Parry, and Eichardson. The existence of the same 
marine animals in the Kamtchatka Sea and Baffin's Bay was 
long since held to prove at least a former North-West passage ; 
but the occurrence of recent sea-shells in banks far inland 
rendered it probable that even recent elevation of the land in 
Arctic America might have much reduced the passage. During 
the " Grlacial period," this Arctic Sea, with the same fauna, ex- 
tended over Britain ; over Northern Europe, as far as the Alps 
and Carpathians ; and over Siberia, and a considerable part of 
North America. The shells now living in the Arctic Seas, are 
found fossil in the deposits of "Northern Drift," over all these 
countries ; and a few of the species yet linger within the bounds 
of the two next provinces, especially in tracts of unusual depth. 
The Arctic shells have mostly a thick greenish epidermis (p. 33) : 
they occur in very great abundance, and are remarkably subject 
to variation of form, a circumstance attributed by Professor E. 
Forbes to the influence of the mixture of fresh water produced 
by the melting of great bodies of snow and ice. 

AUCTIC SHELL-PISH. 
E. Eussian Lapland. F. Finmark. L Iceland. G-. Greenland. D. Davis Straits (west 
coast). B. Behring's Straits. 0. Ochotsk. * British species (living). ** British 
species (fossil). 
Octopus graniilatus. G. | „ amoena. G-. 



Cirroteutliis MiiUeri. G. *Oirmiastrephes todarus. F. Newf. 

Eossia palpebrosa. G. P. Eegent Inlet. I 

Onychoteiithis Bergii. F. B. Limacina arctica. G. 0. 

„ Fabricii. G. 



* Malaco-zoologiaEossica; Mem. del' Acad. Imp. des Sc. Petersb. T. 6, pt. 2, 1S49. 
t Index Molluscorum Groenlandise. Hafn. 1842. 

t Fortegnelse over Grcinlands Bloddyr in H. Rink : Gronland geographisk og statia- 
tisk beskrevet, ii. Bind. 1857. 
$ Hancock, An. Nat, Hist. vol. 18, p. 323, pi. 5. 



58 



MAIOJAL OF THE MOIITJSCA. 



Spirialis stenogyra. F. 
„ talea. G-. 
*Clio borealis. N. Zemla. Gf-. 

*Nassa incrassata. F. 

*Buccmiim undatum, var. Kara. 0. 

., liylrophanum. D. Priucc 
Kegent Inlet. 

„ tenebrosum. E. G-. B. 

* „ Humptireysianum. B. G. 
»» „ cyaneiun. F. D. G. Icy 

C. St. Lawrence. 
„ glaciale. Kar^, 0. C. Parry. 

Gr. Spitzbergen. 
Buccinum angiilosum. N. Zemla. Icy 

C. Spitz. 
„ tenue. N. Zemla. Gr. 
„ Groenlanclicimi. D. 

„ undulatum.. G. 
„ ecalariforme. Gr. 
*» „ ciLLatiim. G. 

„ boreale (Leach). Baffin's B. 
„ sericatum. D. P. Kefuge. 

* „ Hollbollii (Mangelia, Mcil.) 

G. F. 

* „ Dalai. E. B. 
Pleurotoma, 13 sp. G. 

*Fu3Us antiquus. N. Zemla. B. 
•* „ carinatus. G. 

* „ contrarius. E. 0. 
„ deformis. E. Spitz. 

** „ despectus, G. Spitz. 

„ heros. C.Perry. 

„ latericeus. G. 

** „ Sabini. D. Mass. 

„ pellucidus. D. 

„ Kroyeri. G. Spitz. 

„ decemcostatus. B. Ne'wf. 

* „ Bemiciensis. E. B. 
„ Spitzbergensis. Spitz. 

* J, Islandicus. F. 

* ,, gracilis. F. E. G. B. 
»»Trophon clathratus. E. G. B. 

** „ scalariformis. Spitz. Ne^wf. B. 

** „ Gunneri. F. G. 

«* „ craticulatus. E. I. G. 

» „ Barvicensis. F. 

„ barpularius. F. U.S. 

* „ tnmcatus. 
♦Purpura lapUlus. E. G. B. 

Mangelia, 9 sp. G. 

„ decussata. D. 
♦Bela turricula. F. G. 
♦ „ rufa. F. G. 
**Mitra Grcenlandica. G. 
*»Admate viridula. E. Spitz. G. B. 



*Tricliotropis borealis. F. G. B. Prince 
Eegent Inlet. 
„ conica. G. 

„ insignis. B. 

„ bicarinata. B. 

*Natica helicoides. E. G. B. 
** „ clausa, F. N. Zemla. G. Mel- 
\'ille Id. P. Eegent Inlet. B. 
„ pallida. E. O. 
„ flava. N. Zemla. B. Newf. 

* „ pusilla (grcenlandica). G.Norway. 

Spitz. 
„ nana. G. 
*'Velutina leevigata. E B. 

* „ flexilis. F. 

** „ zonata. E. G. 
„ lanigera. G. 
LameUaiia prodita. F. 

„ GrcEnlandica. G. B. 
**ScaLlaxia Grcenlandica. F. G. B. 
*♦ „ borealis (Escbrichti). G. 
Amaura Candida. G. 
Chemnitzia albula. G. 
**Mesalia lactea. G. 
«*Turritella polaris. G. 
Aporrhais occidentalis. Labrador. 
*Littorina obtusata. E. 

* „ tencbrosa. N. Zemla. D, 
„ Grcenlandica. G. F. 

* „ palliata (arctica). G. 
„ limata. F. 

*Lacima vincta. E. Newf. G. 
„ labiosa. F. P. Eefuge. 

* „ crassior. E. 
„ glacialis. G. 

* „ pallidula. G. 

* „ puteolus. F. Newf. 
„ frigida. F. 

„ soUdula. F. 

Hydrobia castanea. E. G. 

Eissoa Bcrobiculata. G. 

„ globulus. G. 

„ saxatUis. G. 

*Skenea planorbis. G. F. 

**Margai'ita cinerea. F. U.S. 

* „ undulata. E. G. 

* „ alabastrum. F. 

* „ helicina. G. White Sea. Spitz. 
„ Bordida. E. Spitz. G. B. 

„ umbilicahs. D. B. 
„ Harrisoni. D. 
„ glauca. G. 
„ Valilii. G. 

* „ costulata. G. 
♦PunctureUa Noachina. F. G. 
♦Acmeea testudinahs. E. Iceland. G. 



AECTie SHELL-FISH. 



59 



**Lepeta ceeca. G. F. Spitz. C. Eden. 

Pilidium rubellum. F. G. D. 

Patella, 4 sp. G. 
♦Chiton ruber. F. Q. Spitz. 
* „ albus. F. G-. 

Dentalium entale. Spitz. 



Bulla Eeinhardi. Q-. 

„ subangulata. Q-. 
*Cylichua alba. Q. F. Spitz. 

„ turrita. Q-. 
*Philine scabra. Norway. G-. 
„ punctata (Moll.) Gr. 
Doris liturata. G-. 
„ acutiuscula. Q-. 
„ obvelata. G-. 
*Dendronotus arborescens. F. 
JEolis bodocensis. Gr. 
Tergipes rupium. Gr. 
EuplocaiQUS Holbollii. Gr. 



*Leda minuta (Fabr.) F. Spitz. G. D. 

* „ lucida. F. ( = navicularis ? Spitz.) 

* „ pygmaea. G. F. Siberia. 
*Yoldia arctica Gr. (myalis). G. U.S. 

Spitzbergen. 
** „ lanceolata (arctica B. & S.) Icy 
Cape. 
„ limatula. F. U.S. Kamt. 
„ hyperborea. Spitz. 
** „ thraciaeformis (angularis). G. 



G. 



*Terebratulina caput-serpentis. Spitz. F. 

Mass. Medit. 
*Waldlieimia cranium. F. 
„ septigera. F. 
Terebratella Spitzbergensis. Sp. 
„ Labradorensis. Labr. 
**Ehynchonella psittacea, E. Baffin's Bay, 
76° N. Melville, I. B. 
* Crania anomala. Spitz. 



*Anomia squamula. E. 

* „ aculeata. E. 

**Pecten Islandicus. F. N. Zemla. Spitz. 
G. B. St. Lawrence. 
„ vitreus. F. Arctic America. 
„ Groenlandicus. E. Spitz. D. 
Limatula sulcata. G. F. 
*Myt.ilus edulis. E. G. B. 
*Modiola modiolus. E. B. 
•Crenella discors (laevigata). G. D. N. 
Zemla. 

* „ decussata. E. G. 

* „ nigra. N. Zemla. E. G. D. 
** „ faba. G. 

„ vitrea. G. 
Area glacialis. P. Begent Inlet. 
Nucula corticata. G. 

„ inflata. G. D. 
Leda buccata. G. 
„ macilenta. G. 
•* „ rostrata (pemula). F. Spitz. Arctic 
America. 



** „ truncata, Br. (Portlandica, Hit.) 

P. Eefuge. Arctic America. 
**Astarte borealis (arctica). F. Iceland. G. 
** „ semisulcata (corrugata). Kara 

Sea. N. Zemla. Spitz. P. 

Eegent Inlet. C. Parry. Icy 

Cape. 

* „ elliptica. F. G. Spitz. 

* „ sulcata. E. N. Zemla. 0. 
** „ crebricosta. F. Spitz. Newf. 

„ crenata. P. Regent Inlet. 
„ Warhami. Davis Str. 
„ globosa. G. 

* „ compressa. N. Zemla. G. 

,, Banksii. Spitz. Baffin's Bay. 
*Cardium edule var. rusticum. E. 

„ Islandicum. N. Zemla. G. 
** „ Grcenlandiciun. Kara. Spitz. 
C. Parry. St. Lawrence. 
„ elegantulum. G. 
*Cryptodon flexuosus. G. F. 
*Turtonia minuta. G. F. 
*Cyprina Islandica. E. Labrador. 
**Cardita borealis. Mass. O. 
**Tellina calcarea. F. G. B. 
** „ GrcEnlandica. (= Balthica, L.) 

N. Zemla. Spitz. F. G. B. 
** „ edentula. B. 
*Mya truncata. E. Spitz. G. C. Parry. B. 
** „ Uddevallensis. St. Lawrence. D. 
P. Eegent Inlet. MelviUe I. 

* „ arenaria. N. Zemla. G. O. 
»*Saxicava rugosa (arctica). N. Zemla. 

Spitz. G. C. Parry. B. 

* „ (Panopaea) Norvegica. White 

Sea. 0. 
Machaera costata. Labrador. O. 
Glycimeris sUiqua. C. Parry. Newt'. 
*Lyonsia Nor^'egica. F. 

„ arenosa. G. D. P. Eefuge. 
*Thracia myopsis. G. 
Pandora glacialis. Spitz. Baff. (Leach). 



60 MAiniAX OF TH? MOLLITSCA. 

II. BoREAii Province. 

Th.e Boreal Province extends across tlie Atlantic from Nova 
Scotia and Massacliusetts to Iceland, tlie Faeroe and Shetland 
Islands, and along the coast of Norway from North Cape to the 
Naze. 

Of the 289 Scandinavian shells catalogued by Dr. Loven,* 
217, or 75 per cent, are common to Britain, and 137 range as 
far as the North coast of Spain. 

The boreal shells of America are described by Dr. Gould, f 
From these lists it appears that out of 270 sea- shells found on 
the coast of Massachusetts north of Cape Cod, more than half 
are common to Northern Earope. 

Many of the species, it is believed, could only have extended 
their range so distantly by means of continuous lines of con- 
necting coast, now no longer in existence. | 

BOREAL SHELLS COMMON TO EUROPE AND NORTH AMERICA. 

* Sritish Species. 

♦Lucina borealis. 
? „ divaricata. 
*Cryptodon flexuosus. 
*Astarte borealis. 

* „ triangularis ? (quadrans, G.) 
*Cyprina Islandica. 
? (Cardium Islandicum, U.S.— N. Zemla). 

Yoldia limatula. 

„ arctica, Gr. (= myalis), 
*Leda pygmaea. 

* „ caudata. 

? „ navicularis (lucida, Loven?) 
*Niicula tenuis. 
*Mytilus edulis. 
*Modiola modiolus. 



*Teredo navalis. 
•Pholas crispata. 
*Solen ensis. 

* (Panopaea) Norvegica. 
*Mya arenaria. 

* „ truncata. 

*Thracia phaseolina (Conradi, Couth). 

Mactra ponderosa (ovalis, Gr.) 
? Montacuta bidentata. 
*Turtonia minuta. 
? Kellia rubra. 

? Lepton nitidum (fabagella, Conr. ?) 
♦Saxicava rugosa (arctica). 

Tellina solidula, var. (fusca, Say). 

* „ calcarea (sordida, Couth). 



* Index Molluscorum Scandinaviae ; extracted from the " Ofversigt af K. Vet. 
Akad. Forh." 1846. The climate of Finmark is much less severe than Russian Lap- 
land ; Ham m erf est has an open harbour all the year. 

+ Report on the Invertebrata of Massachusetts. 1841. 

t Forbes, Memoirs of the Geol. Survey, i. p. 379. Sir John Richardson, when 
speaking of the cod-tribe and turbot-tribe, says:— "Most of the fish of this order feed 
on or near the bottom, and a very considerable number of the species are common to 
both sides of the Atlantic, particularly in the higher latitudes, where they abouud. It 
does not appear that their general diffusion ought to be attributed to migration from 
their native haunts, but rather that in this respect they are analogous to the owls, 
which, though mostly stationary birds, yet include a greater proportion of species 
common to the old and new worlds than even the most migratory families. Several of 
the ScnmberoidecB (Mackerel-tribe) which feed on the surface, have been previously 
noted as traversing many degrees of longitude in the Atlantic : but the existence of 
the ground-feeding Gadoidece in very distant localities must be attributed to a different 
cause, as it is not probable that any of them wander out of soundings or ever approach 
the mid-seas."— Report Zool. N. America, p. 218. 



BOEEA.L PROVINCE. 



61 



•Crenella nigra. 

* „ discors, L. 

* „ decussata (glandula^ Tot.) 
Pecten Islandicus. 

? Ostrea ediilis (borealis, Lam. ?) 
*Anoinia ephippium. 

* „ aculeata. 
„ squamula? 

•Terebratulina caput-serpentis. 
*Eli5Tichonella psittacea. 

*Dendronotus arborescens. 

Polycera Lessonii ? 
? AmphisphjTa hyalina (debilis ?) 

Cyliclma alba (triticea, C.) 

* „ obtusa (pertenuis). 
*Philine quadrata (fonnosa, St.) 



•Cbitou cinereus. 

* „ marmoreus. 

* „ ruber. 

* „ Isevis. 

* „ asellus. 

* „ albus. 
♦Dentalium (entale, L,?) 
PLepeta cseca (candida, G.) 
*Acm3ea testudinalis (amoena, S.) 
♦Puncturella Noachina. 

*Adeorbis divisus ( = Skeneaserpuloides). 
Margarita cinerea. 

* „ costulata?,(Skenea). 

* „ helicina. 



*Margarita jindulata. 

* „ alabastrum (= occidentalis?) 
Littorina groenlandica. 

* „ tenebrosa (vestita). 
„ palliata? 

*Lacuna vincta (divaricata). 

* „ puteolus (Montagui). 
*Skenea planorbis. 
*Velutina laevigata. 

„ zonata. 
*LameUaria perspicua. 
*Natica helicoides. 

„ clausa. 

* „ pusilla. 
*Scalaria groenlandica. 

(lanthina communis). 

Odostomia producta. 

Cancellaria (admete) viridula. 
*Trichotropis borealis. 
*Fusus antiquus (tomatus). 

* „ island. CU3. 

* „ propinquus. 
„ ? rosaceus. 

*Trophon muricatns. 

* „ clathratus. 

„ scalariformis. 

„ harpularius. 
*Purpura lapillus. 
*Buccinum undatum. 

* „ (Conjinella) Dalei. 
*Bela turricula. 

* „ Treveiyana. 

* „ nif a (Vahlii) ? 



* Ommastrephes sagittatus is also common to both, sides of the 
North Atlantic. The genera, 

Machcera, Glycimeris, Cardita, and 

Solemya, Mesodesma {deauratum), Crepidula, 

are peculiar to the American side of the Boreal Province. 

Several other species now living on the coast of the U. States 
occur fossil in England : e. g, Trophon cinereus^ Say., is believed 
to be the Fusus Forhesi, Strickland, of the Isle of Man ; others 
are marked in the Arctic list. 



III. Celtic Pboyince. 

The Celtic province, as described by Prof. E. Eorbes, includes 
the British island coasts, Denmark, Southern Sweden, and the 
Baltic* The fauna of this region (which includes the principal 

* -The great work of Messrs. Forbes and Hanley is the standard text book on 
British Testacea. A new work on British MoUusca is now being prepared by Mr. J. 



62 MAIOTAL OF THE MOLLTJSCA. 

herring-fisheries) is essentially Atlantic ; many of the species 
are of ancient origin, and occur fossil in the Pliocene. 

The British moUusca described by Porbes and Hanley amount 
to 682, viz. :— 

14 (15) Cephalopoda. 100 Pulmonifera. 175 (172) Acephala, 

220 (254) Marine Univalves. 4 (5) Pteropoda. 73 (73) Tunicata. 

91 (100) Nudibranchiata. 6 (7) Brachiopoda. 

Of this number two-thirds of the Nudibranchia, 55 marine uni- 
valves, and 7 bivalve shell-fish, are, at present, only known in 
British seas; but as most of these are minute or ''critical" 
species, it is considered they will yet be met with elsewhere. 
In 1857, Mr. M'Andrew was acquainted with 626 marine mol- 
luscs, as indicated by the figures in brackets in the summary 
just given. 

A few of the species belong to the Lusitanian province, whose 
northern limits include the Channel Islands, and just impinge 
upon our coast. 

PhasiancUa puflus. Miirex corallinus. Cytherea chione. 

Haliotis tuberculata. Avicula Tarentina. Petricola litliophaga. 

TruncateUa Montagui. Galeomma Turtoni. Venerupis irus, 

Oncidium celticum. Pandora rostxata. Cardium rusticum, L. (tnber- 

Bullahydatis. Ervllia castanea. culatum). 

Volva patula. Mactra helvacea. 

Of the Gasteropoda 54 are common to the seas both north and 
south of Britain ; 52 range farther south, but are not found 
northward of these islands ; and 34 which find here their south- 
ern limit occur not only in Northern Europe, but most of them 
in Boreal America. Nearly half of the bivalves range both 
north and south of Britain; 40 extend southward only, and 
about as many more are found in Scandinavia, 27 of them bemg 
common to N. America. {Fortes.) 

In the lists of Arctic and Boreal shells the British species are 
distinguished by an asterisk. 

According to Mr. M 'Andrew's estimate in 1850, 406 British 
shell-bearing moUusca were then known, of which 

217 or 53 per cent, were common to Scandinavia. 
246 or 61 „ „ North of Spain. 

227 or 66 „ „ S. Spain and Medit. 

97 or 24 „ „ Canary Islands. 



G-. Jeffreys. The Nudibranchiata alone have been more fully described in the 
publications of the Ray Society, by Messrs. Alder and Hancock. For the marine 
zoology of the coasts of Denmark the " Zoologia Danica " of 0, P. Miiller is still the 
most important work. 



ITTSITANIAN PEOTINCE. 



63 



The following are at present peculiar to Britain : — 



sp. 
sp. 



Assiminea, 
Jeffreysia, 
Otina Otis. 
Eissoa, sp . 
Stj'lif er turtoni. 



Odostomia, 19 sp. 9 
Buccimun fusiforme. 
Fusus Berniciensis. 

„ Turtoni. 
Natica Kingii. 



The most common edible species are :- 



Ostrea edulis. 
Pecteu maximus. 
„ opercularis. 



Mj'tilus edulis. 
Cardium edule. 
Buccinum imdatum. 



Montacuta f erruginosa. 
Argiope cistellula. 
Pecten niveus. 
Syndosmya tenuis. 
Thracia vUlosiuscula. 



Fusus antiquus. 
Littorina littorea. 



Am.ongst the species characteristic of the Celtic province — or 
most abundant in it — are the following : — 



Trophon muricatus. 
Nassa reticulata. 
Natica Montagui, 

„ monilifera, 

„ nitida. 
Velutina laevigata. 
Turritella communis. 
Aporrbais pes-pelecani. 
Eissoa cingillus. 
Scalaria Trevelyana. 



Littorina littoralis. 

Trochus Montagui. 
„ millegranus, 
„ tumidus. 

Patella vulgata. 
„ pellucida, 

Acmsea virginea. 

Chiton cinereus. 

Scaphander lignarius, 

Tellina crassa, 



Venus striatula. 

„ casina. 
Ponax anatinus. 
Solen ensis. 
Pholas Candida. 
Mactra elliptica. 

„ solida 
Periploma prsetenuis. 
Tliracia distona. 
Syndosmya prismatica. 



The wide expanse of the Baltic affords no shell-fish unknown 
to the coasts of Britain and Sweden. The water is brackish, 
becoming less salt northward, till only estuary shells are met 
with, and the Littorinse and Limnseans are found living to- 
gether, as in many of our own marshes. This scanty list is 
taken from the Memoirs of Dr. Middendorff and M. BoU. 



Buccinum undatum. 
Purpura lapiUus. 
Nassa reticulata. 
Littorina littorea. 
Patella (tarentina). 
Hydrobia muricata. 



Neritina fluviatilis. 
Limnaea auricularia. 

„ ovata. 
Mytilus edulis. 
Donax (trunculus). 
Cardium edule var. 



Tellina Balthica. 

„ tenuis. 
Scrobicularia piperata. 
Mya arenaria. 
„ truncata. 



Meyer and Mobius collected the following species at Kiel : — 



Chiton cinereus. 
Acmssa testudinalis. 
Eissoa labiosa. 

„ inconspicua. 

„ ulvae. 

- ventrosa. 



Eissoa parva. 
Littorina littorea. 

„ littoralis. 

„ tenebrosa. 
Lacuna vincta. 
„ pallidula. 



Cerithium reticulatum. 

Nassa reticulata. 
Buccinum undatum. 
Fusus antiquus. 



IV. LusiTANiAjq- Peovince. 

The shores of the Bay of Biscay, Portugal, the Mediterranean, 
and N. W. Africa, as far as Cape Juby, form one important 
province, extending westward in the Atlantic as far as the Gulf- 



64 



MANUAL OP THE MOLLITSCA. 



weed bank, so as to include Madeira, tlie Azores, and Canary 
Islands.* 

In the Atlantic portion of the province occur the following 
genera, not met with in the Celtic and Boreal seas, although 
two of them, Mitra and Mesalia, occur on the coast of Green- 
land : — 



Argonauta. 


Cancellaria. 


Auricula. 




Philonexis. 


Sigaretus. 


Pedipes. 


Spondylus. 


Chiroteuthis. 


Crepidula. 


Eingicula. 


Avicula. 




Mesalia. 


Umbrella. 


Solemya. 


Coiius. 


Vermetus. 


Glaucus. 


Chama. 


Pleurotoma. 


Possarus. 




Crassatella. 


Marginella. 


Planaxis. 


Carinaria. 


Lithodomus 


Cymba. 


Litiopa. 


Firola. 


Ungulina. 


Mitra. 


Truncatella. 


Atlanta, 


G-aleomma. 


Terebra. 


Solarium. 


Oxygyrus. 


Cardita. 


Colnmbella. 


Bifrontia. 




Cytherea. 


Pisania. 


Turbo. 


Cleodora. 


Petricola. 


Dolium. 


Monodonta. 


Cuvieria. 


Venerupis. 


Cassis. 


Haliotis. 


Creseis. 


Mesodesma 


Triton. 


Gadinia, 




Eryilia, 


Banella. 


Siphonaria. 


Megerlia. 


Panopsea. 



Spain and Portugal, 

The coast of Spain and Portugal is less known than any other 
part of the province, but the facilities for exploration are in 
some respects greater than in the Mediterranean, on account of 
the tides. Shell-fish are more in demand as an article of food 
here than with us, and the Lisbon market afforded to Mr. 
M'Andrew the first indication that the genus Cymba ranged so 
far north. 

On the coasts of the Asturias and Gallicia, especially in Vigo 
Bay, Mr. M'Andrew obtained, by dredging, 212 species, of a 

* In the nortliern part of the Lusitanian province are the Pilchard fisheries ; in the 
Mediterranean, the Tunny, Coral, and Sponge fisheries. 

The Gulf-weed banks (represented in the map) extend from 19" to 47" in the 
middle of the North Atlantic, covering a space almost seven times greater than the 
area of France. Columbus, who first met with the sargasso about one hundred miles 
west of the Azores, was apprehensive that his ships would run upon a shoal. {Hum,' 
boldt.) The banks are supposed by Professor E. Forbes to indicate an ancient coast- 
line of the Lusitanian land-province, on which the weed originated. Dr. Harvey states 
that species of Sargassum abound along the shores of tropical countries, but none 
exactly correspond with the Gulf- weed {S. bacciferum). It never produces fructifica- 
tion—the "berries" being air-vesicles, not fruit — but yet continues to grow and 
flourish in its present situation, being propagated by breakage. It may be an abnormal 
condition of S. vulgar e, similar to the varieties of Fncus nodosus (Mackayi) and 
F. vesiculosus which often occur in immense strata ; the one on muddy sea-shores, the 
other in salt marshes, in which situations they have never been found in fructification. 
( Manual of British Alga, Intr. 16, 17.) 



LTJSITANIAN PEOYIN-Ci:. 65 

somewliat nortliern cliaracter, 50 per cent, of tliem being com- 
mon to Norway, and 86 per cent, common to the soutli of Spain. 

On the southern coast of the Peninsula 353 species were 
obtained, of which only 28 per cent, are common to Norway and 
51 per cent, to Britain. 

The identical species are chiefly amongst the shells dredged 
from a considerable depth (35 — 50 fathoms) ; the littoral species 
have a much more distinct aspect. 

The shells of the coast of Mogador are generally identical 
with those of the Mediterranean and Southern Peninsula. 

Canary Islands. The shells of the Canaries collected by MM. 
Webb and Berthelot,* and described by M. D'Orbigny, amount 
to 124, to which Mr. M'Andrew has added above 170. Of the 
300 species 17 per cent, are common to Norway, 32 per cent, to 
Britain, and 63 per cent, to the coasts of Spain and the Medi- 
terranean. Two only are W. Indian shells, Neritina viridis and 
Colurribella cribaria. Of the African shells found here, and not 
met with in more northern localities, the most remarkable are : — 

Crassatella divaricata. Banella laevigata. Cymba proboscidalis. 

Cardiuna costatum. Cassis flammea. Conus betulinus. 
■ Lucina Adaiisoni. „ testiculus. „ Prometheus. 

Cerithium nodulosum. Cymba Neptuni. „ G-uinaicus. 

Miiros saxatilis. „ porcina, „ papilionaceus. 

Madeira. Mr. M'Andrew obtained 156 species at Madeira, of 
which 44 per cent, are British, 70 per cent, common to the 
Mediterranean, and 83 to the Canaries. Amongst the latter 
are the two W. Indian shells before mentioned, and the follow- 
ing African shells : — 

Pedipes. Mitra fusca.- Patella crenata. 
Littorina striata. „ zebrina. „ guttata. 

Solarium. Marginella guancha. „ Lowei. 

Scalaria cochlea. Cancellaria. „ Candei. i 

Natica porcellana. Monodonta Beri;heloti. Pecten corallinoides. 

Azores. Amongst the littoral shells which range to the 
Azores, are Pedipes, Littorina striata, Mitra fusca, and Ervilia 
castanea; the other species obtained there are Lusitanian. 
(^M'Andrew.) 

The Mediterranean fauna is known by the researches of Poli, 
Delle Chiaje, Philippi, Yerany, Milne-Edwards, Professor E. 
Forbes, and Deshayes. In its western part it is identical with 
that of the adjacent Atlantic coasts ; the number of species 
diminishes eastward, although reinforced by a considerable 

* Hist. Naturelle des Ties Canaries ; the list of shells is reprinted, with the additions 
made by Mr. M'Andrew, as 00,6 of the Catalogues of the British Museum. 



66 MANTIAL OF THE MOLLUSCA. 

number of new forms as yet only known in tlie Mediterranean ; 
and a few accessions (about 30) of a different cbaracter from tbe 
Eed Sea. The total number of shell-bearing species is esti- 
mated at 600, viz. : — 

Cephalopoda 1 NucleobrancMata ... 6 Lamellibranchiata 200 

Pteropoda 13 Gasteropoda 370 Brachiopoda 10 

On the coast of Sicily, M. Philippi has found altogether 619 
marine mollusca, viz. : — 

Bivalves 188 Pteropoda 13 Gasteropoda 319 

Brachiopoda 10 Nudibranchs 54 Cephalopoda 15 

Of the 522 which are provided with shells, 162 have not been 
found fossil, and are presumed to be of post- tertiary origin, so 
far as concerns their presence in the Mediterranean. The re- 
maining 360 occur fossil in the newer tertiary strata, along with 
nearly 200 others which are either extinct or not known living 
on those coasts ; a few of them are living in the warmer regions 
of Senegal, the Eed Sea, and the West Indies : — 

Senegal. Antilles. Red Sea. 

Lucina columbella. Lucina pennsylvanica. Argonauta hians. 

Cardium hians. Vermetus intortus. Dentalium elephantinum. 

Terebra fusca. Terebra duplicata. 

Morocco. Phorus agglutinans. 

Trochus strigosus. Niso terebellum. 

Pecten medius. 
Diplodonta apicaUs. 

Most of them, however, are of northern origin, such as : — 

Saxicava rugosa Tellina crassa. Ehynchonella psittacea. 

(Panopasa) Norvegica. Cyprina Islandica. Patella vulgata. 

Mya tnmcata. Leda pygmaea. EuHmella Scillae. 

Periploma praetennis. Limopsis pygmsea. Buccinum undatum. 

Lutraria solenoides. Ostrea eduUs. Fusus contrarius. 

Of the 522 Sicilian testacea, about 35 (including 10 oceanic 
species) are common to the West Indies — ^if the species have 
been correctly determined ; 28 are stated, with more probability, 
to be common to West Africa, including Murex Brandaris and 
other common species ; *74, including Murex trunculus, are com- 
mon to the E-ed Sea ; Crania ringens cannot be distinguished 
from the species found in New South Wales {Davidson) ; and 
Columhella corniculum ranges from the north coast of Spain to 
Australia, the specimens from these distant localities being only 
distinguishable as geographical varieties. [Gaskoin.) Six othei 
species are included in Menke's Australian Catalogue, but re* 
quire verification. 

The following genera, nine of which are naked molluscs, are 



LUSITAKIAN PEOYINCE. 67 

supposed to be now peculiar to tlie Mediterranean ; tte small 
number of species show they are aberrant or expiring forms. 
Cassidaria, and Thecidium are ancient, widely-distributed 
genera, and the Mediterranean Thecidium occurs fossil in 
Britlany and the Canaries. 

Thysanoteutlii3, 2 sp. Scseurgua, 1. Morrisia, 2, 

Verania, 1. Pleurobranclisea, 1. Thecidium, 1. 

Dosidicus, I. Tethys, 1. Scacchia, 2. 

Doridium, 1. Cassidaria, 6 

Icarus, 1. Pedicularia, 1. 

The genera Fasciolaria, Siliquaria, Tylodina, Notarchus, Verti- 
cordia .2 Glavagella, and Crania, occur only in this portion of the 
Lusitanian province. 

Amongst the peculiar species are : — 

Nassa semistriata. Argiope cuneata. Artemia lupinug. 

Fusus crispus. Clavigella angulata, Trigona nitidula. 

Tylodina Eaftuesquii. Spondylus Gussonii, Luciaopsis decussata. 

Crania rostrata. Astarte bipartita. 

u^gean Sea. Prof. E. Forbes obtained 450 species of moUusca 
in the ^gean, belonging to the following orders : — 

Cephalopoda 4 Nudibranchs 15 Brachiopoda 8 

Pteropoda 8 Opisthobranchs 28 Lamellibranchs 143 

Nucleobranchs 7 Prosobranchs 217 Tunicafa 22 

Of these Vl were new species, but several have since been 
found in the Atlantic, and even in Scotland.* The only marine 
air-breather met with was Auricula myosotis. 

Black Sea. In the northern part a few Aralo- Caspian shells 
are found, otherwise the Black Sea only differs from the Medi- 
terranean in the paucity of its species ; Dr. Middendorjff enume- 
rates 68 only. The water is less salt, and there is no tide, but 
a current Hows constantly through the Dardanelles to the 
Mediterranean, f 

LorenzJ found 178 molluscs at Quarnero, of which 75 were 
bivalves, and 88 univalves; 75 of them extended their range 
into the -S^gean Sea, 58 into the Boreal province. Few only 
appeared to be peculiar to the Adriatic. 



* Trans. Brit. Assoc, (for 1843), 1844, p. 130. 

t A current from the Atlantic sets in perpetually through the Straits of Gibraltar, 
and there is scarcely any tide ; it only amounts to one foot at Naples and the Euripus, 
two feet at Messina, and five at Venice and the Bay of Tunis. 

t Physikalische Verhaltnisse und Vertheilung der Organismen im Quamerischen 
Golfe. Wien, 1863. 



68 MAliTUAL OF THE MOLLITSCA. 

y. Aralo- Caspian Peoyin-ce. 

The only inland salt-seas tliat contain peculiar shell-fisli are 
the Aral and Caspian. The shells chiefly consist of a remarkable 
group of Cockles which burrow in the mud (see fig. 213, p. 402). 
No explorations have been made with the dredge, but other 
species, probably still existing in these seas, have been found in 
the beds of horizontal limestone which form their banks and 
extend in all directions far over the steppes. This limestone is 
of brackish water origin, being sometimes composed of myriads 
of Cydades, or the shells of Dreissena and Cardium, as in the 
islets near Astrakhan. It is believed to indicate the former 
existence of a great inland sea, of which the Aral and Caspian 
are remnants, but which was larger than the present Mediter- 
ranean at an age previous to that of the Mammoth and Siberian 
Rhinoceros. The present level of the Caspian is 83 feet below 
that of the Black Sea ; that of the Aral has been stated to be 
117 feet higher than the Caspian, but is probably not very 
different; their waters are only brackish, and in some parts 
drinkable. The steppe limestone rises to a level of 200 — 300 
feet above the Caspian ; it spreads eastward to the mountains 
of the Hindoo Kush and Chinese Tartary, southward over 
Daghestan and the low region E. of Tiflis, and westward to the 
northern shores of the Black Sea. The extent to which it has 
been traced is represented by oblique lines on the map.* 
Some of the Caspian shells still exist in the Sea of Azof and the 
estuaries of the Dnieper and Dniester. Our information upon 
this seldom-visited region is derived from the works of Pallas, 
Eichwald,t Ejrynicki,} Middendorff, and Sir Eoderick Mur- 
chison. 

Aralo-^ Caspian Shells, 
A, Aral ; C, Caspian ; B, Black Sea. 
The Species marked * are found also in the Steppe limestone. 
•Cardium edule, L. C. (very small) B. Baltic. 

„ edule, var. (rusticum, Chemn.) A. C. B. Icy Sea. 
*Didacna trigonoides, Pal. C. (Azof. M. Hommaire). 

„ Eichwaldi, KrjTi. (crassa, Eich.) C. B. (Nikolaieff ). 
Monodacna Caspia, Eich. C. 

„ pseudo-cardium, Desh. (pontica, Eich.) B. 
Adacna laeviuscula, Eich. C. 
„ vitrea, Eich. C. A. 



* From a sketch kindly prepared by Professor Ramsay. 

t G-eogr. des Kaspischen Meeres, des Kaukasusund des Siidlichen B.isslands. Berlin, 
16<W. Fauna Caspio-Caucaaica, 1841. 
i Bull, des Nat. Moscow, 1837. 



WEST APEICAN PEOVIKTCE. 69 

•Adacna edentula, Pallas. C. 

„ jdicata, Eich. C. B. (Dniester, Akerman, Odessa). 

„ colorata, Eich. C. B. (Azof, Dniepei-). 
•Mytilus edulis, L. C. C. (not in Middendorff's list). 

„ latus, Chemn. B. 
•Dreissena polymorpha, Pal. C. B. 

Paludinella stagnalis, L. (pusilla Eich.) C. B. (Odessa) Ochotsk. 
* „ variabilis, Eich. C. 
•Neritina liturata, Eich. C. on sea-weed. 
♦Eissoa Caspia, Eich. C. 

„ oblonga, Desm. B. 

„ cylindracea, Kryn. B.* 

The following species are described by Eicbwald, from the 
steppe limestone. (Murchison, Eussia, p. 297.) 

" Paludina " Triton. Donax priscus. 

„ exigua. Mactra Caspia. Monodacna propinqua. 
Ei.soa conus. „ Karagana. „ intermedia. 

„ dimidiatus. Cyclas Ustuertensis. „ Catillus. 

Bullina Ustuertensis. Mytilus rostriformis. Adacna prostrata. 

No other inland bodies of salt water are known to haye 
peculiar marine shells ; those of the modern deposits, in Meso- 
potamia (at Sinkra and Warka), collected by Mr. W. K. Loftus, 
are species still abounding in the Persian Gulf.f 



yi. West Aeeican Peovii^ce. 

The tropical coast of Western Africa is rich in conchological 
treasures, and far from being wholly explored. The researches 
of Adanson4 Cranch (the naturalist to the Congo expedition§), 
and the officers of the Niger expedition, have left much to be 
done. Dr. Dunker has described 149 species in his Index Moll. 
Guinece, coll. Tarns. Cassel, 1853. 

At St. Helena, Mr. Cuming collected 16 species of sea-shells, 
7 of them new. Littorina Helenoe is found on the shore of St. 
Helena, and L. miliaris and Nerita Ascensionis, at Ascension. 

* The Velutina [Limneria) Caspiensis. A. Ad. was founded on a specimen of 
Limnaa Gebleri, Midd. (1851), from Bemaoul, Siberia. 

t A species of coral {Porites elongata, Lam.), now living at the Seychelles, has been 
said to be found in the Dead Sea (v. Humboldt's Views of Nature, Bohn ed. p. 260); 
also Melania costata and M. Jordanica, according to M. Schubert. 

X Hist. Nat. de Senegal, 4to. Paris, 1757. This able but eccentric naturalist 
destroyed the utility of his own writings by refusing to adopt the bi-nomial nomen- 
clature of LinNjEus, and employing instead the most barbarous chance-combinationa 
of letters he could invent. 

§ Appendix to Captain Tuckey's Narrative (1818), by Dr. Leach. 



70 



MAXITAL OF THE MOLLUSC A. 



Onychoteuthis, 3sp. 
Craut'hia, 2 sp. 
Strombus rosaceus. 
Triton ficoides. 
Eanella qiiercina. 
Dolium tessellatum. 
Harpa rosea. 
Oliva hiatula. 
Pusionella. 
Nassa Pfeifferi. 
Desraoulinsia. 
Pui'pura nodosa. 
Rapana bezoar. 
Murex vitulinus. 

„ angularis. 

„ megaceros. 

„ rosarius. 

„ duplex. 

„ cornutus. 
Clavella? filosa. 

,, afra. 
Lagena nassa. 
Terebra striatula. 

„ ferruginea. 
? Halia priamus. 
Mitra nigra. 
Cymba. 



West' African Shelh. 

Marginella. 
Persicula. 

Pleurotoma mitrifonnis. 
Tomella lineata. 
Clavatula mitra. 
„ coronata. 
„ bimarginata. 
„ vii'ginea. 
Conus papilionaceus. 

„ genuinus. 

„ testudinarius. 

,, achatinus. 

„ monachus. 
Natica t'ulminef^. 
Cypraea stercoraria. 

„ picta. 
Vermetus lumbricalis. 
Cerithium Adansonii. 
Turritella torulosa. 
Mesalia. 

Littorina punctata. 
Collonia. 

Clanculus villanus. 
Haliotis virginea. 

„ coccinea. 
Nerita Senegalensis. 
„ Ascensionis. 



Pecten . bbus. 
Area V n r cosa. 

„ senilis. 
Cardiuni ringens. 

„ costatuin. 
Lucina columbelia. 
ITngulina rubra. 
Diplodonta rosea. 
Cardita ajar. 
Artemis africana. 

„ tonida. 
Cj'clina Adansonii. 
Trigcna bicolor. 

„ tripla. 
Cytherea tumens. 
„ africana. 
Venus plicata. 
Tellina. 

Strigilla Senegalensis. 
Gastrana polj'gona. 
Mactra depressa. 

„ rugosa. 

„ nitida. 
Pholas clausa. 
Tugonia anatina. 

Discina radiosa. 



VII. South Africai^ Phoyince. 

The fauna of South Africa, beyond the tropic, possesses few 
characters in common with that of the western coast, and is 
more like the Indian Ocean fauna, as might be expected from 
the direction of the currents. But, together with these it has a 
large assemblage of marine animals found nowhere else, and the 
** Cape of Storms '' forms a barrier between the populations of 
the two great oceans, scarcely less complete than the far-pro- 
jecting promontory of South America. The coast is generally 
rocky, and there are no coral-reefs ; accumulations of sand are 
frequent, and sometimes very extensive, like the Agulhas Bank. 
The few deep-sea shells which have been obtained off these 
banks possess considerable interest, but explorations in boats 
are said to be diflB.cult, and often impossible on account of the 
surf. Shells from the Cape are too frequently dead and water- 
worn specimens picked up on the beach. The shell-fish of South 
Africa have been collected and described by Owen Stanley, 
Hinds, A. Adams, and especially by Dr. Krauss, who has 



INDO-PACIFIC PROVINCE. 



71 



published a very complete monograpL..* Of 400 sea-shells 
recorded in this work, above 200 are peculiar, and most of these 
belong to a few littoral genera. Only 1 1 species are common 
to the coast of Senegal, whilst 18 are found in the Red Sea ; 15 
species are said to be found in Europe ; all the others, not pecu- 
liar, exist on the E. coast of Africa. 



Panopsea natalensis. 
Solen marginatus. 
Mactra spengleri. 
Gastrana ventricosa. 
Nucula pulchra, Hinds. 
(L'Agullias bank, 70 fm.) 
Pectunculus Belcheri, 120 

fm. 
Modiola Capensis. 

„ pelagica, Forbes. 
Septifer Kraussi. 

Terebratulina ubyssicola, 

132 fm. 
Terebratella (Kraussia). 
„ rubra. 

„ cognata. 

„ pisum. 

„ Deshayesii, 

120 fm. 

Chiton, 16 sp. 
Patella, 20 sp. 

„ cochlea. 

„ compressa. 



South African Shells 
Patella apicina. 
„ longicosta. 
„ pectinata, &c, 
Siphonaria, 5 sp. 
Pupillia (aperta). 
Fissurella, 10 sp. 
Crepidula, 4 sp. 
Haliotis sanguinea. 
Delphinula granulosa. 

„ cancellata. 
Trochus, 22 sp. 
Turbo sarmaticus. 
Littorina Africana 7 sp. 
Phasianella, 6 sp. 
Bankivia varians. 
Turritella, 4 sp. 
Pleurotoma, 6 sp. 
Clionello (sinuata). 
Tj'phis arcuatus. 
Triton dolarius. 

,. fictilis, 50-60 fm. 
Harpa crassa. 
Cominella ligata. 

„ lagenaria. 

„ limbosa. 



Cominella tigrina. 
Bullia laevissima. 

„ achatina. 

„ natalensis. 
Nassa plioosa. 

„ capensis. 
Cyclonassa Kraussi. 
Eburna papillaris. 
ColumbeUa, 5 sp. 
Ancillaria obtusa. 
Mitra, 5 sp. 

Imbricaria carbonacea. 
Voluta armata. 
„ scapha. 

„ abyssicola, 132 fm. 
Marginella rosea. 
Trivia ovulata. 
Cypraea, 22 sp. 
Luponia algoensis. 
Cyprovulum (rapense). 
Conus, 8 sp. 

Octopus argus. 
Sepia, 4 sp. 



The following are stated to be common to the Cape and Euro- 
pean seas.f 

Saxicava (arctica?) Greenland, Medit. Chama gryphoides, Medit. Bed Sea. 

Tellina fabula, Brit. Medit. Pecten pusio, Brit. 

Lucina lactea, Medit. Bed Sea. 

„ fragilis, Medit. Diphyllidia (lineata?) N. Brit. Medit. 
Venus verrucosa, W. Indies ? Brit. Senegal, Eulima nitida, Medit. 

Canaries, Red Sea, Australia ? Purpura lapillus ?? (not in Medit.) 

Tapes pullastra. North Sea. Nassa marginulata. 

„ geographica, Medit. Octopus vulgaris ? Brit. 

Area lactea, Medit. Argonauta argo, Medit. 

YIII. InDO-PaCIFIC PEOVrNCE. 

This is by far the most extensive area over which similar 
shell-fish and other marine animals are distributed. It extends 
from Australia to Japan, and from the Bed Sea and oast coast 

* Die Siidafrikanischen Mollusken, 4to. Stutt. 1848. 

t Marks of doubt are added to some of the species, and others are omitted. 



72 



MAinJAL OP THE MOLLUSC A. 



of Africa to Easter Island in tlie Pacific, embracing three-fifths 
of the circumference of the globe and 45° of latitude. This 
great region might, indeed, be subdivided into a number of 
smaller provinces, each having a particular association of species 
and some peculiar shells, such as the Eed Sea, the Persian Gulf, 
Madagascar, &c. ; but a considerable number of species are 
found throughout the province, and their general character is 
the same.* Mr. Cuming obtained more than 100 species of 
shells from the eastern coast of Africa, identical with those 
collected by himself at the Philippines, and in the eastern coral 
islands of the Pacific, f This is pre-eminently the region of 
coral reefs, and of such shell-fish as affect their shelter. The 
number of species inhabiting it must amount to several thou- 
sands. The Philippine Islands have afforded the greatest 
variety, but their apparent superiority is due, in a measure, to 
the researches of Mr. Cuming ; no other portion of the province 
has been so thoroughly explored. ;]: 

Amongst the genera most characteristic of the Indo-Pacific, 
those marked (*) are wholly wanting on the coasts of the At- 
lantic, but half of them occur fossil in the older tertiaries of 
Europe. Those in italics are also found on the west coast of 
America. 



*Nautilus. 


»Magilus. 


Stomatella. 


Hemicardium 


*Pteroceras. 


*Melo. 


Gena. 


*Cypricardia. 


"Eimella. 


Mitra. 


*Broderipia. 


*Cardilia. 


*Eostellaria, 


*Cylindra. 


*Eiiniila. 


* Verticordia. 


•Seraphs. 


♦Imbricaria. 


*Neritopsi3. 


*Pytliina. 


Conus. 


Ovvdum. 


*Scutel]ma. 


Circe. 


Fleurotoma. 


*PyTula (type). 


*Linteria. 


*Clementia. 


*Cithara. 


*]Vroiioptygma. 


*DolabeUa. 


»Glaucomya. 


*Clavella. 


Pliorus. 


*Hemipecteii. 


*Mer6e. 


•Turbinella (typ.) 


Siliquaria. 


*Placuna. 


Anatinella. 


Cyllene. 


*Quoyia. 


*Malleus. 


CulteUus. 


Ebuma. 


♦Tectaria. 


*VulseUa. 


*Anatina. 


Phos. 


Imperator. 


*Peduin. 


*Ch8ena. 


Dolium. 


Monodonta. 


*Septifer. 


*Aspergillum. 


Harpa. 


Delphinula. 


*Cucullaea. 


*Jouannetia. 


►Ancillaria. 


Liotia. 


*Hippopu3. 


*Lingula. 


►Bicinuia. 


*Stom.atia. 


*Tridacna. 


Discina. 



The strictly littoral species vary on each great line of coast : 
for example, Littorina intermedia and Tectaria ^agodus occur on 



* See Mrs. Somerville's Physical Geography, ii. p. 233. 

t Journal Geol. Soc. 1846, vol. ii. p. 268. 

t Mr. Cuming collected 2,500 species of sea-shells at the Philippines, and estimates 
the total number at 1,000 more. The genera most developed are Conus, 120 sp. ; 
Fleurotoma, 100 ; Mitra, 250; Oolumbella, 40; Cyprcea, 50; Natica, 50; Chiton, 30; 
Tellina, 50. 



I 



INDO-PACIFIC PEOVINCE. 



73 



the east coast of Africa; Littorina conica and melanostoma, in 
the Bay of Bengal ; Littorina sinensis and castanea, and Haliotis 
venusta, on the coast of China ; Littorina scahra and IT. squamata, 
in N. Australia ; H. asinina, New Guinea ; and L. picta, at the 
Sandwich Islands. 

Bed Sea (Erythraean). 

Of the 408 moUusca of the Eed Sea, collected by Ehrenberg 
and Hemprich, *74 are common to the Medit., from which it 
would seem that these seas have communicated since the first 
appearance of some existing shells. Of the species common to 
the two seas 40 are Atlantic shells which have migrated into the 
Eed Sea by way of the Medit., probably during the newer 
pliocene period; the others are Indo-Pacific shells which ex- 
tended their range tp the Mediterranean at an earlier age. 

The genera wanting in the Medit. but existing in the Eed 
Sea, show most strikingly their diversity of character, and the 
aflB.nity of the latter to the Indian fauna. 



Pteroceras. 


Ancillaria. 


Sipbonaiia. 


Limopsis. 


Strombus, 8 sp. 


Harpa. 


Placuna. 


Tridacna. 


Eostellaria. 


Eicinula, 


Plioatula. 


Crassatella. 


Turbinella. 


Magilus. 


Pedum. 


Trigona. 


Terebra. 


Pyramidella. 


Malleus. 


Sanguinolaria, 


Eburna. 


Parmophorus. 


Vulsella. 


Anatina. 


Oliva. 


Nerita. 


Perna. 


Asperglllum. 



Other genera become abundant, such as Conus, of which there 
are 19 species in the Eed Sea, Vyproea 16, Mitra 10, Cerithium 
17, Pinna 10, Chama 5, Circe 10. 

Persian Gulf. 

The marine zoology of the Persian Gulf and adjoining coast 
has not been yet explored.* The following shells were picked 
up on the beach at Kurrachee by Major Baker, with many 
others evidently new, but not in a satisfactory state for descrip- 
tion. (1850.) 



EogteUariacurta. 

Murex tenuispina var. 

Pisania spiralis. 

Eanella tuberculata. 
„ spinosa, 
„ crumena. 

Triton lampas. 

Bullia sp. 

Eburna spirata. 



Purpura persica, 

„ carinifera. 
Columbella blanda. 
Oliva subulata. 

„ Indusica. 

„ ancillaroides. 
Cypraea Lamarckii. 

„ ocellata. 
Natica pellis-tigrina. 



Sigaretus sp. 
Odostomia sp. 
Pliorus corrugatus. 
Planaxis sulcata. 
Imperator Sauliee. 
Monodonta sp. 
Haliotis sp. 
Stomatella imbricata. 
„ sulcifera. 



* The "Brindled Co^Nxy'>'> {Cyprcea princeps) , fvom the Persian Gulf, was value.! 
ftt £50. 



74 



MANUAL OF THE MOLLUSCA, 



Fissurolla Ruppellii. 

„ Indusica. 

,, salebrosa. 

„ dactylosa. 

„ funiculata. 
Pileopsis tricarinatus. 
Nerita ustulata. 
Dentalium octangulatum. 
Ringicula sp. 
Bulla ampulla. 
Anomia acheeus. 

„ enigmatica. 
Pecten sp. 
Spondylus sp. 
Plicatula depressa. 
Mytilus eanaliculatus. 
Area obliquata. 

„ soulptiJis, &c. 
Chama sp. 
Lucina sp. 
Cardium fimbriatum. 

„ latum. 



Cardium impolitum. 
„ pallidum. 
„ assimile. 
Venns pinguis. 
„ cor. 
„ purpurata. 
Meroe Solandri. 



Trigona trigonella ? 
Artemis angulosa, 

„ exasperata. 

„ subrosea? 
Venerupis sp. 
Petricola sp. 
Tapes sulcosa. 

„ Malabarica. 
CjTjricardia vellicata. 
Cardita crassicostata? 

„ calyculata. 

„ Tankervillii. 
Mactra ^Egyptica, &c. 
Tellina angulata. 



Tellina capsoides. 
Mesodesma Horsfieldii. 
Psammobia sp. 
Syndosmya sp. 
Semele sp. 
Solen sp. 

Solecurtus politus. 
Donax scortum. 

„ scalpellum. 
Sanguinolaria diphos. 
„ violacea. 

„ sinuata. 

Corbula sp. 
Diplodonta sp. 
Anatina rostrata. 
Pandora sp. 
Martesia sp. 
Pholas australis. 

„ Bakeri, Desh. 

„ orient alis. 
(Meleagrina v. p.416). 



At the Oargados or St. Brandon 'fehoals, north of Mauritius, 
Voluta costata, Conus verrucosus, Pleurotoma virgo, and Turhinella 
Belcheri have been obtained by dredging. 

Collections of marine shells have been made at Madagascar 
and the Mascarene Islands by Sganzin, and at the Seychelles by 
Dufo. The number obtained at the latter place was 263, of 
which 220 were univalves. Two of the univalves, viz., JDolium 
galea and Cyprcea helvola, and two of the bivalves, are found in 
the Mediterranean. 



IX. Australo-Zelandic Peoyin'cE. 

Most remote from the Celtic seas, this province is also most 
unlike them in its fauna, containing many genera wholly un- 
known in Europe, either living or fossil, and some which occur 
fossil in rocks of a remote period. The province includes New 
Zealand, Tasmania, and extra-tropical Australia, from Sandy 
Cape, on the east, to the Swan River. The shells, which are 
nearly all peculiar, have been catalogued by Gray,* Menke,t 
and Forbes. t Of the following genera some are peculiar (*), 
others attain here their greatest development : — 



•* Travels in New Zealand, by Dr. E. Dieffenbach. 8vo., London, 184''. 

t MoU. Nov. HoUandiae, 1843. 

t Narrative of the Voyage of H.M.S. Battlesnake, 1846-50, by J. Macgillivray. 

opplement by Professor E. Forbes. 



JAPONIC PROVINCE. 



*Pinnoctopua. 
•Struiliiolaria. 

Phasianella. 

Elenchus. 

Bankivia. 

Eotella. 
•Macroschisma. 

Parmophorus. 

Risella. 



♦Macgillivraia. 

•Amphibola, 

*Ti-igonia. 

•Chamostrea. 

•Mj'adora. 

*MyocIiama. 

Crassatella. 

Cardita. 

Circe. 



Cypricardia. 

Mesodesma. 

Terebratella. 

Spirula. 

Oliva. 

Conus, 

Voluta. 

Terebra. 

Fasciolaria. 



Imperator. 

Monoptygma. 

Siphonaria. 

Pandora. 

Anatinella. 

Clavagella. 

Placunomia. 

Waldheiinia. 

Crania. 



Some of the genera of tliis proyince are only met with else- 
where at a considerable distance : — 



Solenella — Chili. 
Panopsea— Japan. 
Monoceros— Patagonia. 



Bankivia — Cape. 
KJraussia — Cape. 
Solemya — Medit. 



Ehynchonella— Arctic seas. 
Trophon — Fuegia ; „ 
Assiminea — India; Brit. 



Amongst the littoral shells of South Australia are Ealiotis 
elegans, H. rubicunda, and Littorina rugosa. Haliotis iris and 
Littorina squalida are found on the shores of N. Zealand ; and 
Cyprovula umhilicata in Tasmania. 

Mr. Gray's New Zealand list amounts to 104 marine species, 
among which are three volutes, including V. magnifica, the 
largest of its genus; Stromhus troglodytes, Ranella argus, the 
great Triton variegatus ; 6 Cones (all doubtful), Oliva erythros- 
toma, Cyprcea caput-serpentis, Ancillaria australis, Imperater 
heliotropium, Chiton monticularis, &c. 

Venus Stutchhuryi and Modiolarca trapezina have been found 
at Kerguelen's Id. and Patella illuminata at the Auckland Ids. 



X. Japonic Peovince. 

The Japanese Islands and Corea represent the Japonic pro- 
vince. Our knowledge of its molluscan fauna ie still scanty, 
notwithstanding the successful researches of Mr. Adams. Up- 
wards of 130 species were collected in the harbour of Decima, 
by Dr. Nuhn, of which 113 were Prosobranchiates. 



Octopus areolatus. 
Sepia clrrysopthalma. 
Sepiola Japonica. 

Conus Sieboldi, 
Pleurotoma Coreanica. 
Terebra serotina. 
„ stylata. 
Ebuma Japonica. 
Cassis Japonica. 
Murex eurypterus. 

„ rorifluus. 

„ plorator. 

„ Burneti. 



Purpura, 5 sp. 

Fusus. 

Cancellaria nodulifera. 

Mitra. 

Strombus corrugatus. 

CjT)raea fimbnata. 

„ miliarig, 
Mangelia, 4 sp. 
Triforis, 5 sp. 
Natica, 5 sp. 
Trochus, 15 sp. 
Radius birostris. 
Cerithium longicaudatum. 
Imperator Guilf ordiae. 

e2 



Haliqtis Japonica. 

„ discus. 

„ gigantea. 
Bxilla Coreanica. 
Siphonaria Coreanica. 
Pecten asperulatus. 

„ Japonicus. 
Spondylus Cumingii. 
Nucula mirabilis. 

„ Japonica. 
Cardium Bechei. 
Crassatella compressa. 
Diplodonta alata. 

„ Coreanica. 



76 



MAjSTUAL or THE MOLLTJSCA. 



Isocardia Moltkiana. 
Venus Japonica. 
Cyclina orientalis. 
Cji;herea petechialis. 
Artemis sericea. 
„ biluaata. 



Ai'temis Sieboldi, 
„ Japonica. 
Circe Stutzeri. 
Tapes Japonica. 
Petricola radiata. 
Solen albidus. 



- Panopsea Japonica. 
Terebratulina Japonica, 

„ angusta. 

Waldhettnia G-rayi. 
Terebratella Coreanica. 

„ rubella. 



XI. ALEUTLAJsr Province. 

The Boreal province is represented on the northern coasts of 
the Pacific, where, according to Dr. Middendorff, the same 
genera and many identical species are found. In addition to 
those indicated in the Arctic list (p. 57), the following species 
occur at the Shantar Ids. in the Sea of Ochotsk (0), Saghalien, 
the Kuriles (K), Aleutians and Sitka (S). 



Patella (scui-ra). S. 
Acmeea, 3 sp. S. 
PUidiiun commodum. O. 
Paludinella. 3 sp. O. 
Littorina, 6 sp. 0. K. S. 
Turritella Esclu-ichtii. 0. 
Margarita sulcata. A. 
Trochus, 6 sp. S. 
Scalaria Ochotensis. 
Crepidula Sitcliana. 
„ minuta. S. 
„ grandis. A. 
Fissurella violacea. S. 

„ aspera. S. 
Haliotis K*amtschatica. 
„ aquatilis. K. 
Velutina coriacea. K. 

„ ciyptospira. O. 
Tricliotropis inermis. S. 
Purpura decemcostata. (Mid.) S. 
^ Freycineti. O. S. 
„ septentrionalis. S. 
Pleurotoma Scbantarica. 
„ simplex. O. 
Murex monodon. S. 

„ lactuca. S. 
Fusus (Chrysodomus) Sitchensis. 
„ decemcostatus. A. 
„ Scliantaricus. 



Fusus Behringii. 
„ Baerii. A. 
„ luridus. S. 
Buccinum undatum var. Schantaricum. 

„ simplex. 0. 

„ Ochotense. 

„ cancellatum. A. 

„ ovoides. 0. 
Pisania scabra. A. 
Bullia ampullacea. O. 
Onychoteuthis Kamtschatica. 



Terebratella frontalis. O. 
Placunomia macroschisma. 
Pecten rubidus. S. 
Crenella vernicosa. 0. 

„ cultellus. Kamt. 
Nucula castrensis. S. 
Pectunculus septentrionalis. 
Cardita borealis. 0. 
CardiumNuttall). S. 

„ Californicum. S. 
Saxidomus Petiti. S. 

„ giganteus. S. 
Petricola cylindracea. S. 

„ gibba. S. 
Tellina lutea. A. nasuta. 

„ edentula. A. 
Lutraria maxima. S. 



O. 



The influence of the Asiatic coast- current is shown in the 
presence of two species of Haliotis, whilst afiinity with the fauna 
of W. America is strongly indicated by the occurrence of Patella 
(scurra), three species of Crepidula, two oi Fissurella, and species 
of Bullia, Placunomia, Cardita, Saxidomus, and Petricola, which 
are more abundant, and range farther north than their allies in 
the Atlantic. 



ALEUTIA2f PEOYINCE. 77 

Additional information on the fauna of this province has been 
recently supplied by Mr. Lord, the naturalist to the British 
North American Boundary Commission Expedition, and by Dr. 
Kennerley, the naturalist to the American North-west Boundary 
Exploring Expedition. The results obtained are discussed by 
Dr. P. P. Carpenter.* 

Provinces on tlie Western Coast of America. 

The moUusca of the Western coast of America are equally 
distinct from those of the Atlantic and those inhabiting the 
central parts of the Pacific. 

Mr. Darwin states in his Journal (p. 391) that " not one single 
sea-shell is known to be common to the Islands of the Pacific 
and to the west coast of America," and he adds that " after the 
comparison by Messrs. Cuming and Hinds of about 2000 shells 
from the Eastern and Western coasts of America, only one 
single shell was found in common, namely the Purpura patula, 
which inhabits the West Indies, the coast of Panama, and the Gral- 
lapagos. " Even this single identification has since been doubted. 
Mr. Cuming, who resided many years at Valparaiso, did not 
discover any West India specimens on that coast, and M. 
D'Orbigny makes the same observation. On the other hand 
M. Morch, of Copenhagen, says he has received Tellina opercu- 
lata and Mactra alata from the west coast and also from Brazil ; 
and M. Deshayes gives the following extraordinary ranges in 
his " Catalogue of Veneridce in the British Museum ": — 

Artemis angulosa, Philippines — CliUi. 
Cytherea umbonella, Eed Sea — Brazil. 

„ maculata, W. Indies — Philippines, Sandwich. 

„ circinata, W. Indies — ^West coast America. 

In these instances there is doubtless some mistake, either 
about the locality or the shell. As regards the last, Mr. Carrick 
Moore has shown that the error has arisen from confounding 
the Cytherea alternata of Broderip with C. circinata of Born, 
M. D'Orbigny collected 628 species on the coast of S. America, 
— 180 from the eastern side, and 447 from the Pacific coast, be- 
sides the Siphonaria Lessonii which ranges from Valparaiso in 
Chili to Maldonado on the coast of Uruguay, t These shells 
belong to 110 genera, of which 55 are common to both coasts, 

* British Association Report for 1863. 

t The dispersion of this coast shell may perhaps have taken place at the time when 
the channel of the river S. Cruz formed a strait, joining the Atlantic and Pacific 
oceans, like that of Magellan. (Darwin, p. 181.) Mr. Couthouy makes 3 s^.—Siphojiaria 
7.e.5.9own', nearly smooth, Atlantic coast; S. antarctica, ribbed, Pacific coast; and A 
lateralis, thin, oblique, Fuegia. 



78 MANUAL OF THE MOLLUSCA. 

while 34 are peculiar to the Pacific, and 21 to the Atlantic side 
of S. America ; an extraordinary amount of diversity, attribut- 
able partly to the different character of the two coasts — the 
eastern low, sandy or muddy ; the western rocky, with deep 
water near the shore.* 

The comparison of the shells of Eastern and "Western America 
is of considerable interest to geologists ; for if it is true that 
any number of living species are common to the Pacific and 
Atlantic shores, it becomes probable that some portion of the 
Isthmus of Darien has been submerged since the Eocene Ter- 
tiary period. Any opening in this barrier would allow the 
Equatorial current to pass through into the Pacific — there 
would be no more Gulf stream — and the climate of Britain 
might, from this cause alone, become like that of Newfoundland 
at the present day. 

Although geological researches seem to show that not only 
the Isthmus of Darien, but even the Eocky Mountains, were 
sufficiently submerged during the Miocene Epoch to allow of 
the free intermingling of the waters of the Atlantic and Pacific, 
yet the special temperate moUuscan fauna of E. and W. America 
are very dissimilar. There are no grounds for believing a single 
species to be identical. There are, however, a large number of 
species (upwards of 50) living on both sides of the northern por- 
tion of the continent, and the majority of these exist in the 
British seas. 

XII. CALiFOBisriAN Peoyince. 

The shells of Oregon and California have been collected and 
described by Mr. Hinds, t Mr. Nuttall,| Mr. Couthouy, natu- 
ralist of the American Exploring Expedition ;§ Mr. Cooper, 
Dr. Gould, Mr. Binney,|l Dr. Kennerley, Colonel Jewitt, and 
others.^ 

Shells common to U. California and Sitka. (Middendorff.) 

Littorina modesta. Tfochus ater. Trochus emyomphalus. 

„ aspera. „ moestns. Petricola cylindracea. 

Fissurella violacea. „ Fokkesii. Lutraria maxima. 

„ aspera . 



* Voyage dans 1' Amerique Meridionale. 1847, t. v. p. v, 

t Voyage of H.M.S. Sulphur ; Zoology by E. B. Hinds, 4to. 1844. 

X Described by T. A. Conrad. Journ. Acad. N. S. Philadelphia, 1834. 

% G-ould in Bost. Nat. Hist. Soc. Proceedings, 1846 ; and U. S. Exploring Exped- 
(Commander Wilkes), vol. xii, MoUusca, with Atlas. 4to. Philad. 1852. 

II Explorations for a railroad route from the Mississippi to the Pacific Ocean. 1856. 

\ P. P. Carpenter on Mollqsca of West Coast of North America. British Association 
Report for 1863. 



TANAMIC PEOVIlSrCE. 



79 



Scarcely any species are common to this province (extending 
from Puget Sound to the peninsula) and the Bay of California, 
which belongs to the Panamic province. The most important 
genera are Chiton, 18 species; Acmsea, 11 species; Pissurella, 
6 species; Haliotis, 6 species; Trochus, 15 species; Purpura, 
9 species. The following list probably contains some shells 
which should be referred to the Panamic province. 



Fusus Oregonensis. 
Murex Nuttalli. 
Monoceros unicarinatus. 

„ punctatus. 
Cancellaria urceolata. 
Trivia Californica. 
Natica herculea. 

„ Lewisii. 
Calyptrsea fastigiata. 
Crepidula exuviata. 
„ navicelloides. 
„ solida, &c. 
Imperator Buscliii. 
Haliotis Cracherodii. 

„ fulgens. 

„ corrugata. 
Fissm'ella crenulata. 
„ cucullata. 
Puncturella, 2 sp. 
Dentalium politum. 
Patella, 15 sp. 
Acmeea scabra. 

„ pintadina. 
Chiton Mertensii. 



Cliiton scrobiculatus, &c. 
Cleodora exacuta. 

Waldlieimia Califomica. 
Discina Evausii. 

Anomia pernoides. 
Placunomia cepa. 
Hinnites giganteus. 
Perna, 1. Pinna, 2. 
Mytilus, 1. Pecten, 2. 
Mytilimeria Nuttalli. 
Modiola capax. 
Chama lobata. 
Cardita ventricosa. 
Cardium, 4. 
Lucina, 3. 

Cliironia Laperousii. 
Solecardia ebumea. 
Venus Californiensis. 

„ callosa. 
Artemis ponderosa. 
Saxidomus Petiti. 
„ Nuttalli. 



Saxidomus giganteus. 
Venerupis cordieri. 
Petricola mirabilis. 
Mactra, 2. Donax, 1. 
Tellina Bodegensis. 

„ secta, &c. 
Semele decisa. 
Cumingia Californica. 
Sanguinolaria Nuttalli. 
Lutraria Nuttalli. 
Platyodon cancellatus. 
Ampliicheena Kindermanni, 
Lyonsia, 1. Thracia, 1. 
Pandora, 1. Saxicava, 2. 
Cyathodonta undulata. 
Sphenia Californica. 
Periploma argentaria. 
Solecurtus subteres. 
Machaera lucida. 

„ maxima. 
Mya truncata. 
Panopaea generosa. 
Pholas Californica. 
„ eoncamerata. 



XIII. Pajstamic Peoyince. 

The Western coast of America, from th.e Gulf of California to 
Payta in Peru, forms one of the largest and most distinct pro- 
vinces. The shells of Mazatlan and the Gulf have been imper- 
fectly catalogued by Menke. The Mazatlan moUusks have 
been examined by Mr. P. P. Carpenter, who enumerates 654 
species. The total number of marine shells known belonging 
to this province is 1,341. Amongst these are included 27 
Chitonidse, 13 Acmaeidse, 18 Fissurellidse, 64 Trochoidse, 28 
Calyptrseidse, 69 Pyramidellidse, 59 Buccinidse, and 90 Muri- 
cidse. The gulf of California, together with the adjacent coast 
as far as Mazatlan and St. Bias, has yielded 768 shells (502 uni- 
valves and 266 bivalves), of which 439 also occur in the Gulf of 
Panama, while 117 extend into S. America; 635 species are 
known from the Gulf of Panama ; of these, 266 are peculiar to 



I 



80 MANUAL OF THE MOLLTJSCA. 

tho district, and 163 also occur in S. America. The fauna of 
the Panama province is remarkably distinct from the other W. 
American provinces, and especially the Caribbsean. At one 
time it was thought that it did not possess a single species 
identical with any occurring in the West Indies or the east side 
of America. Dr. P. Carpenter, however, has shown that 35 
marine shells (15 univalves and 20 bivalves) occur on both sides 
of the Isthmus of Darien, and this number has been lately 
increased. 

A few of the species even extend as far as "W". Africa accord- 
ing to Dr. Carpenter; he mentions 15, and among them the 
following : — Crepidula unguiformis, C. aculeata, Hijpponyx anti- 
quatus, Bankivia varians, Natica maroccana, Marginella coerides- 
cens, Nitidella guttata, Purpura jpansa. Pive species are common 
to Mazatlan and the British coasts, viz., Kellia suhorhicularis, 
Lasea rubra, Saxicava arctica, Cytherea Dione, Hydrobia idvcB. 
Still more remarkable is the absence of resemblance between 
the faunas of Panama and those of the Indo-Pacific area, there 
being only seven forms common to the two. Thus, Cytherea 
petichialis occurs in Japan; Nassa acuta, in Australia; and 
Oliva Dudosii, Natica maroccana, Nitidella criharia, Hipponyx 
barhatus, H. Grayanus, are scattered over the Pacific ocean. 

The river-openings of this coast are bordered by mangroves, 
amongst which are found Fotamides, Areas, Cyrenas, Potamo- 
myas. Auriculas, and Purpuras, whilst Littorince climb the trees 
and are found upon their leaves. The ordinary tide at Panama 
amounts to 16 or 20 feet, the extreme to 28 feet, so that once a 
fortnight a lower zone of beach may be examined and other 
shells collected. The beach is of fine sand, with reefs of rocks 
in the bay. 

Oallapagos Islands. — Out of 111 sea-shells collected hereby 
Mr. Cuming, 43 are unknown elsewhere; 25 occur in Mazatlan, 
22 in Central America, 38 in Panama, but only 11 in South 
America. 



LiMorcd shells common to Panama and the Gallapagos (C. B. Adams.] 

Cyprsea rubescens. ColiunLella nigricans. Turbinella cerata. 

Mitra tristis. Eicinula reeviana. Pleurotoma eccentrica. 

Planaxis planicostatus. Cassis coarctata. Hipponyx radiata. 

Pmpura carolinensis. Oniscia tuberculosa. Rssiu-ella macrotrema. 

Columbella atramentaria. Conus brunneus. „ nigro-punctata. 

„ bicanalifera. „ bux. Siphonaria gigas. 

„ heemastoma. Strombus granulatus. 



PERUTIAN PEOVINCE. 



Ptrcmbtis gi'acilior. 
Mai'ex erythrostomus. 
„ regius. 
„ imperialis. 
„ radix, 
rt brassica. 
„ monoceros. &c. 
Rapana muricata. 

„ Kiosquifonnis. 
Myristica patula. 
Eicinula clatlirata. 
Purpura, many sp. 
Monoceros, many sp. 

„ brevidentatus. 
„ cingulatus. 
Clavella? distorta. 
Olivia poiphyria. 

„ splendidula, &c. 
Northia pristis. 
Harpa crenata. 
. Malearingen?. 
Mitra Inca, &c. 
Terebra luctuosa, &c. 
Conus regularis, &c. 
Pleurotoma, many sp. 
Cancellaria goniostoma, 
„ cassidiformis. 

„ clirysostoma. 

Columbella, many sp. 



Panama shells. 

Columbella strombiformis. 
Marginella curta. 
Cj^raea nigro-punctata. 
Trivia. 

Pyi'ula ventricosa. 
Natica glalica. 
Pileopsis hungaricoides. 
Crucibulitm auriculatum, &c 
Trochita mamillaris. 
Crepidnla arcuata, &c. 
Littorina pulchra. 
Turritella Cahfornica. 
Triincatella. 2 sp. 
Coeciim, 8 sp. 
Imperator unguis, &c. 
Troclius pellis serpentis, 
Vitrinella, 12 sp. 
Nerita ornata. 
Patella maxima. 

Discina strigata. 

„ Oumingii. 
Lingula semen. 

„ albida. 

„ audebardi. 

Placunomia foliacea. 
Odtrea eequatorialis. 
Spondylus princeps. 



Pecten magnificus. 
Area litliodomus, &c. 
Pectunculus tessellatus, See- 
Nucula exigua. 
Leda, 5 sp. 
Cardium senticosum. 
,, maculosum. 
, Cardita laticosta. 
G-ouldia Pacifica. 
Cjrtherea, many sp. 
Venus gnidia, 

„ histrionica. 
Artemis Dunkeri. 
Trigona crassatelloides. 
Cyclina subquadrata. 
Venerupis foliacea, 
Petricola Californica, &c. 
Tellina Bui-neti. 
Cumingia coarctata. 
Semele, 7 sp. 
Saxicava purpurascens.. 
GastrochEena. 
Soleciirtus lucidus. 
Lyonsia brevifrons. 
Pandora arcuata, &c. 
Pholas melanura, &c. 
Parapliolas. 
Jouannetia peutinata. 



Xiy. Peruvian Province. 

The coast of Peru and Chili, from Callao to Valparaiso, affords 
a large and characteristic assemblage of shells, of which only a 
small part have been catalogued, although the district has been 
well explored, especially by D'Orbigny, Cuming, and Philippi. 
M. D'Orbigny collected 160 species, one-half of which are 
common to Peru and Chili, whilst only One s|)ecies {Siphonaria 
Lessonii) found at Callao was also met with at Payta, a little 
beyond the boundary of the region. Mr. Cuming obtained 222 
species on the coast of Peru, and 172 in Chili. Hup^ has- 
described 201 species in Gay's work on Chili. The island of 
Juan Fernandez is included within this province. Only a few 
of the Peruvian mollusks can be here enumerated. 



Onychoteuthis peraptoptera. 

^olis Inca. 
Doris Peruviana. 



Diphj'llidia Cuvieri. 
PosterobranchEea. 
Aplysia Inca. 
Tornatella venusta. 
E 3 



Chiton, many sp. 
Patella scurra. 
Acmsea scutum, 
Crucibulum iignarium. 



I 



82 

Trocllita radians. 
Crepidula dilatata. 
FissUrella, many sp. 
Liotia Cobijensis. 
Gadinia Peruviana, 
liittorina Peruviana. 
„ araucana. 
Eissoina Inca. 
Cancellaria buccinoides. 
SigaretUs cymba. 
Fusus Fontainei. 
Murex liorridus. 
Kanella Ventricosa. 
Triton scaber. 
Nassa dentifera. 
Colunibella sordida. 



MANTTAL OF THE MOLLTJSCA. 



Oliva Peruviana. 
Rapana labiosa. 
Mouoceros giganteus. 

„ crassilabris. 

„ acuminatus. 

Purpura chocolata. 
Concholepas, 
Mitra maura. 

Terebratella Fontainei. 
„ Chilensis. 

Discina lamellosa. 
„ l£evis. 

Pholas subtruncata, &c. 
Lyonsia cuneata. 



Solen gladiolus, 
Solecurtus Dombeyl, 
Mactra Byronensis. 
Mesodesma Chilensis. 
Cumingia lamellosa. 
Semele rosea, &c. 
Petricola, many sp. 
Saxidomus opacus, &c. 
Cyclina Kroyeri. 
Venus thaca. 
Crassatella gibbosa. 
Nucula, many sp. 
Leda, many sp. 
Solenella Norrisii. 
Lithodomus Peruvianus, 
Saxicava solida. 



XV. Magellanic Peovln-ce. 

This region includes the coasts of Tierra del Fuego, the Falk- 
land Islands (Malvinas), and the mainland of South America, 
from P. Melo, on the east coast, to Concepcion, on the west. It 
is described by M. D'Orbigny and Mr. Darwin (Journal, p. 177 
et seq.). Philippi also has given attention to it; he assigns 88 
species to the district near the Straits of Magellan. Only 15 
species are known from the Malvinas, and 11 of these haye not 
been met with elsewhere. The southern and western coasts are 
amongst the wildest and stormiest in the world; glaciers in 
many places descend into the sea, and the passage round Cape 
Horn has often to be made amidst icebergs floating from the 
south polar continent. The greatest tides in the straits amount 
to 50 feet. " In T. del Fuego the giant sea-weed {Macrocystis 
jpyriferd) grows on every rock from low-water mark to 45 
fathoms, both on the outer coast and within the channels ; it 
not only reaches up to the surface, but spreads over many 
fathoms and shelters multitudes of marine animals, including 
beautiful compound Ascidians, various patelliform shells^ Trochi, 
naked mollusca, cuttle-fish, and attached bivalves. The rocks, 
at low water, also abound with shell-fish which are very dif- 
ferent in their character from those of corresponding northern 
latitudes, and even when the genera are identical the species are 
of much larger size and more vigorous growth."* 

Shells of the Magellanic Province (* Falkland Islands). 
Buccinmn antarcticum. Monoceros imbricatus. Trophon Magellanicus. 

„ Donovani? „ glabratus. Voluta Magellanjca. 

BuUia cochlidium. „ calcar. „ ancilla. 



* Shell-fish are here the chief support of the natives as well as of the wild animals. 
At Low's harbour a sea-otter was killed in the act of carrying to its hoi*" a large 
Volute, and in T. del Fuego one was seen eating a cuttle-fish. — Darwin. 



PATAGONIAN PROVINCE. 



83 



Natica limbata. 

Lamellaria antarotica. 

Littorina caliginosa. 

Chemnitzia Americana. 
*Scalaria brevis. 
*Trochita pileolus. 

Crepidula Patagonica. 

Troclius Patagonicus. 
^Margarita Malvinee. 
*Scissurella conioa. 
*Fissurella radiosa. 

Puncturella conica. 

Nacella cjonbularia, 
*Patella deaurata. 



*Patella barbara. 

* „ zebrina. 
Siphonaria lateralis. 
Chiton setiger. 
Doris luteola, 
iEolis Patagonica. 

*Spongiobrancli8ea. 
Spiralis? cucullata, 66' S. 

Terebratella crenulata. 

* „ Magellanica, many 

varieties. 
Waldheimia dilatata. 
Pecten Patagonicus. 



Pecten corneus, 

Mytilus Magellanicus. 
*Modiolarca trapezina, 

Leda sulculata. 
*Cardita Thouarsii. 
*Astarte longirostris, 
*Venus exalbida. 
*Cyamium antarcticum. 

Mactra edulis. 
*Lyonsia Malvinensis. 

Pandora cistula. 

Saxicava antarctica. 

Octopus megalocyathus. 



XVI. PATAGONIAJf PEOVIjSrCE. 

From S. Catliarina, south of the Tropic, to P. Melo. This 
coast-line has shifted considerably since the era of its present 
fauna. M. D'Orbigny and Mr. Darwin observed banks of recent 
shells, especially Potamomya lahiata, in the valley of La Plata 
and the Pampas around Bahia Blanca. Mr. Cuming also met 
with Valuta BrasiUana, and other living shells, in banks 50 
miles inland. Of 79 shells obtained by M. D'Orbigny on the 
coast of N. Patagonia, 51 were peculiar, 1 common to the Falk- 
land Ids., and 27 to Maldonado and Brazil. At Mttldonada 37 
species were found, 8 being special. 10 common to N. Patagonia, 
2 to Eio, and 17 to Brazil. Of the latter 8 range as far as the 
Antilles ; viz. : 



Crepidula aculeata. 

„ protea. 
Pholas costata. 



Mactra fragilis. 
Venus flexuosa.* 
Lucina semi-reticulata. 



Modiola viator. 
Plicatula Baa-badensis. 



At Bahia Blanca, in lat. 39^ S., the most abundant shells 
observed by Mr. Darwin (p. 243) were 

Oliva auricularia. Oliva tehuelchana. Voluta angulata. 

„ puelchana. Voluta BrasiUana. Terebra Patagonica, 

M. D^Orbigny's list also includes the following genera and 
species : — 

^olis. 

Paludestrlna. 

Scalaria. 

Natica. 

Chiton. 

Solen. 

Lutraria. 

Donacilla, 

Nucula. 



Octopus tehuelchus. 
Columbella sertularium. 
BuUia globulosa. 
Pleurotoma Patagonica. 
FissurellidBsa megatrema. 
Panopsea abbreviata. 
Periploma compressa. 
Lyonsia Patagonica. 
Solecurtua Platensis. 



Leda. 

Cytherea. 

Petricola. 

Corbula. 

Pinna. 

Mytilus. 

Lithodomus. 

Pecten. 

Ostrea. 



* The variety of Venus flexuosa found at Rio can be distinguished from the West 
Indian shell, which is the Venus punctifera of Gray. 



84 



MAirCTA-L OF THE MOLLUSCA. 



XVII. CAHIEBEAlsr Proviis'cb. 

The Grulf of Mexico, the West Indian Islands, and the eastern 
coast of South America, as far as Eio, form, the fourth great 
tropical region of marine life. The number of shells is esti- 
mated by Prof. C. B. Adams at not less than 1500 species. Of 
these 500 are described by M. D'Orbigny in Eamon de la Sagra's 
History of Cuba, and a small number of the Brazilian species 
in the same author's Travels in South America. A list of the 
Barbadoes shells has been given by Sir E. Schomburgk. 

The coasts of the Antilles, Bermuda, and Brazil, are fringed 
with coral reefs, and there are considerable banks of gulf- weed 
at some distance from the coast of the Antilles. 

West India Sheila. 



Argonauta. 


Ommastrephes. Cleodora. 


Cheletropis. 


Octopus. 


Sepioteutlus. Creseis. 


lantliina. 


Philonexis, 


Sepia 


Cuvieria. 


Glaucus. 


Loligo. 


Spirula. • Atlanta. 


Kotarchus Plei 


Cranchia. 


Hyalea. Oxygryus. 


Aplysia. 


Onychoteulhis. 








Strombus gigas. 


Clavatula zebra. 


Hipponys mitmla. 


pugilis. 




Margin ella. 


Pileopsis militaris. 


Mui'ex calcitrapa. 




Erato Maugerise. 


Calyptraea equestris. 


Pisania articulata. 




Cypr^a mus. 


Crepidula aculeata. 


„ turbinella. 




„ exantiiema. 


Patella leucopleura. 


Triton pilearis. 




„ spurca, &G. 


Chiton sqtiamosus. 


„ cutaceus. 




Trivia pediculus. 


Hydatina physis. 


Fusus morio. 




Ovulum gibbosum. 




Easciolaria tulija. 




Natica caurena. 


Boucliardia tulipa. 


Lagena ocellata. 




Pyramidella dolabrata. 


Discina antillarum. 


Cancellaria reticulata 




Plan axis nucleus. 




Fulgur axuanum. 




Littorina zic-zac. 


Placunomia foliata. 


Terebra acicularis. 




„ flava. 


Plicatula cristata. 


Myristica melongena 




„ lineolata. 


Lima scabra. 


Purpura patula. 




Tectaria muiicata. 


Mytilus exustus. 


„ deltoidea. 




Modulus lenticularis. 


Lithodomus dactylus. 


Oniscia oniscus. 




Fossarus. 


Area Americana. 


Cassis tuberosa. 




Truncatella caribbsea. 


Yoldia tellinoides. 


„ flammea. 




Torinia cylindracea. 


Cliama arcinella. 


„ Madagascarien 


sis. 


Turritella exoleta. 


„ macrophylla. 


Columbella mercatoria. 


„ imbricata. 


Carditim Iffivigatum. 


„ nitida, &c 




Trochus pica. 


Lucina tigrina. 


Voluta vespertilio. 




Imperator tuber. 


„ Pennsj'lvanica, 


„ musica. 




„ calcar. 


„ Jamaicensis. 


Oliva brasiliensis. 




Fissurella Listeri. 


Corbis fimbriata. 


„ angulata. 




„ nodosa. 


Coralliophaga. 


„ jaspidea. 




,, Barbadensis. 


CrassateRa. 


„ oryza, &c. 




Nerita. 


Gouldia parva. 


Ancillaria glabrata. 




Neritina. 


Venus papliia. 


Conus varius, &c. 




Hemitonia 8 radiata. 


„ dysera. 



TITANS- ATLANTIC TEOTINCE. 



85 



Venus crenulata. 
„ cancellata. 
„ violacea. 
Cjnherea dione. 
„ circinata, 
„ maculata, 
„ gigantea. 
„ flexuosa. 



Artemis concentrica. 

„ lucinalis. 
Cyclina saccata. 
Trigona mactroides. 
Petricola lapicida. 
Capsula coccinea. 
Tellina Braziliana. 

„ bimaculata. 



Strigilla camaria. 
Seraele reticulata. 
„ variegata. 
Cumingia. 

Iphigenia Brasiliensis. 
Lutraria lineata. 
Periploma ineequivalvis. 
Pholadomya Candida, 



XVIII. Tkans-Atlaittio Pbovince. 

The Atlantic coast of the United States was supposed by Prof. 
E. Forbes to consist of two provinces : (1) the Virginian, from 0. 
Cod to 0. Hatteras, and (2) the Carolinian, extending to Florida; 
but no data were supplied for such a division. The total num- 
ber of mollusca is only 230, and 60 of these range farther north, 
1 5 being moreover common to Europe. These two regions are 
sometimes treated of together as the Pennsylvanian province. 

Dr. Grould describes 110 shells from the coast of Massachusetts 
south of Cape Cod, of which 50 are not found to the northward, 
but form the commencement of the proper American type. The 
shells of New York and the southern Atlantic States are de- 
scribed by De Kay, in the State Natural History of New York ; 
this list supplies 120 additional species, of which at least a few 
are stragglers from the Caribbean province; e.g. Chama arcinella, 
Iphigenia laevigata, Capsula deflorata* 

M. Massachusetts. Y. New York, SO. South Carolina. F. Florida. 



Conus mus. F. 

Fusus cinereus. M. SO. 

Nassa obsoleta. M. F. (Mex.) 

„ trivittata. M. SC. 

„ vibex. M. F. (Mexico). 
Purpura Floridana. (Mex.) 
Terebra dislocata. Y. SC. 
Pyrula? papyracea. F. 
Fulgur carica. M. SC. 

„ canaliculatum. M. SC. 
Oliva literata. SC. 
Marginella camea. F. 
Fasciolaria distans. SC. (Mex. 
Columbella avara. M. Y. 
Eanella caudata. M. Y. 
Natica duplicata. Y. SC. 
Sigaretus perspectivus. Q. SC. 
Scalaria lineata. M. SC. 

„ multistriata. M. Y. 

„ turbinata. NC. 



Cerithium'ferrugineum. F. 

„ 4 sp. M. 
Triforis nigro-cinctus. M. 
Odostomia, 6 sp. M. Y. 
Turritella interrupta. M. Y. 

„ concava. SC. 
(Vermetus lumbricalis. M. P) 
Calyptreea striata. Y. 
Crepidula convexa. M. Y. 

„ fomicata. M. F. (Mex). 
Littorina irrorata. Y. 
FissureUa alternata. (Say) ? 
Chiton apiculatus. M. SC. 
Tornatella puncto-striata. M. Y. 
Bulla insculpta. M. Y. 



Ostrea equestris. SC. F. 
Pecten irradians {scallop). 
Avicula Atlantica. F. 
Mjiiilus leucophantus. SC. 



* Tlie sea-shells, of the United States have also been collected and desoribed by 
Say, Le Sueur, Conrad, and Couthouy. 



86 



MAIfiril OF THE MOLLtrSCA. 



Modiola Caf olinensis. 


Mactra similia. SC. M. 


„ plicatula. M. Y. 


„ solidissima. M. Y. 


Pinna muricata. SC. 


„ lateralis. M. Y. 


Area ponderosa. SC. 


liUtraria lineata. F. 


„ pexata. M.F. 


„ canaliculata. Y. T?. 


„ ineongrtta. SC. 


Mesodesma arctata. M. Y. 


„ transversa. M. Y» 


Tellina tenta. M. SC. 


Solemya velum. M. Y. 


„ 8 Sp. SC. F. 


„ borealis. M. 


Semele sequalis. SC. 


Cardium ventricosum. SC. 


Ciuningia tellinoides. M. 


„ Mortoni. M. Y. 


Donax fossar. Y. 


Lucina contracta. Y. 


„ variabilis. Gr. F. 


Astarte Mortoni. Y. 


Solecurtus fragilis. M. SC. 


„ bilunnlata. F. 


„ caribbffius. M. F. 


Cardita incrassata. F. 


CorbUla contracta. M. F. 


Venus mercenaria. M. SC. 


Periploma Leana. M. Y. 


„ Mortoni. SC. F. 


„ papjTacea. M. Y 


„ gemma. M. Y. 


Lyonsia hyalina. Y. 


Artemis discus, SC. 


Pandora trilineata. M. F. 


Petricola dactylus. M. SC. 


P'holas costata. SC. F. 


„ pholadiformisi Y» 


„ semicostata. SC. 



LAND BEGIONS. 

Distribution of Land and Fresh-water Shells. 

Tlie boundaries of tlie Natural-history land-regions are more 
distinctly marked, and have been more fully investigated, tban 
their counterparts in the sea. Almost every large island has its 
own fauna and flora ; almost every river system its peculiar 
fresh- water fish and shells ; and mountain- chains like the Andes 
appear to present impassable barriers to the "nations" of 
animals and plants of either side. Exceptions, however, occur 
which show that beyond this first generalisation there eadsts a 
higher law. The British Channel is not a barrier between two. 
provinces, nor is the Mediterranean ; and the desert of Sahara 
separates only two portions of the same zoological region. In 
these and other similar instances the " barrier" is of later date 
than the surrounding fauna and flora. 

It has been often remarked that the northern part of the map 
of the world presents the appearance of vastly- extended, conti- 
nental plains, much of which is, geologically speaking, new 
land. In the southern hemisphere the continents taper off into 
promontories and peninsulas, or have long since broken up into 
islands. Connected with this is the remarkable fact that only 
around the shores of the Arctic Sea are the same animals and 
plants found through every meridian ; Jtnd that in passing south- 
Ward, along the three principal lines of land, specific identities 



LAJfD HEGIOJTS. 87 

give way to mere identity of genera ; these are replaced by family 
resemblances, and at last even the families of animals and plants 
become in great measure distinct, not only on the great conti- 
nents, but on the islands, till every little rock in the ocean haa 
its peculiar inhabitants — the survivors, seem.ingly, of tribes 
which the sea has swallowed up. (Waterhouse.) 

The two largest genera, or principal types of the land and 
fresh-Water shells, Helix and Unio, have an almost universal 
range, but admit of many geographical subdivisions.* Amongst 
the land- snails are several species to which a nearly World-wide 
range has been assigned, sometimes erroneously, as when Helix 
cicatricosa is a,ttributed to Senegal and China, or Helix similaria 
Per. to Brazil and India ; and often correctly, but only because 
they have been carried to distant localities by human agency. 
Land-snails are in favour with Portuguese sailors, as ' ' live sea 
stock; " and they have naturalised the common garden-snail of 
Europe {Helix aspersa) in Algeria, the Azores, and Brazil ; and 
Helix lactea at Teneriffe and Mte. Video. Achatina fidica has 
been taken from Afirica to the Mauritius, and thence to Calcutta, 
where it has been established by a living naturalist ; and Helix 
hortensis has been carried from the old country to America, and 
naturalised on the coast of New England and the banks of the 
St. Lawrence. Bulimus Goodalli, indigenous to the West Indies 
and S. America, has been introduced into English pineries and 
to Mauritius. Helix jpulchella, one of the small species found in 
moss and decayed leaves, inhabits Europe, the Caucasus, 
Madeira, the Cape (introduced), and N. America as far as the 
Missouri. Helix cellaria inhabits Europe and the Northern 
States of America, and has been carried abroad with the roots 
of plants, or attached to water-casks, and naturalised at the 
Cape and New Zealand. Testacella maugei has been transported 
from the Canary Islands to England. 

The fresh-water Pulmonifera — Limncea, PJiysa, Planorhis, 
Ancylus — and the amphibious Succinea, have a nearly world- 
wide range ; and like aquatic plants and insects, often re-appear, 
even at the antipodes, under familiar forms. The range of the 
gill-breathing fresh-water shells is more restricted. 

The Old World and America may be regarded as provinces of 
paramount importance, having no species in common (except a 

* In cataloguing Unio7iidce, the river and country of eacli species shotild be stated. 
American authors are too often contented with recording such localities as "Nash- 
ville '' and " Smithville," which are quite unintelligible. Almost as uncertain in their 
meaning are S. Vincent, S. Cruz, S. Thomas. Prince's Id. ; whilst the latinised names 
of places often defy all attempts at re-translation. 



88 



MANUAL OP THE MOLLITSCA. 



few in the extreme nortli), and each possessing many charac- 


teristic genera. 








America. 


OM World. 


Amerida. 


Old World. 


Anastoma. 


Zonites. 


Choanopcma, 


Pomatias. 


Tridopsis. 


Nanina. 


Chondropoma. 


jOtopoma. 


Sagda. 


Vitrina. 


Cistula. 


Craspedopoma. 


Stenopus. 


Helicolimax. 


Trochatella. 


Diplommatina. 


Proserpina. 


Daudebardia. 


Alcadia. 


Aulopoma. 


Bulimus. 


Achatina. 


Stoastorna. 


Pupina. 


Odontostomus. 


Acliatinella, 


Geomelania. 


Acicula. 


Liguus. 


'Clausilia. 






Crlandina. 


Paxillus. 


Hemisinus. 


Vibex. 


Cylindrella. 


Pupa. 


Melafusiis. 


Pirena. 


Megaspira, 




Ceriphasia. 


Melanopsis. 


Simpulopsis, 


Testacella. 


Ancuiotus. 


Paludomus. 


Amphibulima, 


Pamiacella. 


Melatoma. 


Lithoglj'pbus. 


Omalonyx. 


Limax. 


Amnicola. 


Navicella. 




Arion. 






Philomycus, 


Pliospliorax, 


MLilleria. 


^therla. 


Peltella. 


Incilaria. 


Mycetopus. 


Iridina. 




Oncidium, 


Castalia. 


Galatea. 


Chilinia. 




Monocondylaea. 


Cj'renoides. 


Gundlachia. 


Latia. 


Gnathodon. 


Glaucomya. 



The Land Proyinces represented on the map are the principal 
Botanical Eegions of Prof. Schouw, as given in the Physical 
Atlas of Berghaus ; and it is proposed to inquire how far these 
divisions are confirmed by the land and fresh-water shells, more 
especially by the land-snails [Helicidce, Limacidce, and Cydosto- 
midoe), which have been so elaborately catalogued by Dr. L. 
Pfeifi'er.* 

The first Botanical region — that of Saxifrages and Mosses- — 
has not been numbered on the map, although its boundary is 
given by the line of northern limit of trees. This line nearly 
coincides with the Isotherm of 32°, or permanent ground-frost; 
but in Siberia the pine-forests extend 15° farther, owing to the 
absence of winter rains and the bright clear air. 

In this region shells are very rare ; Dr. Middendorfi" found 
Physa hypnorum in Arctic Siberia, and Limnoea geisericola (Beck) 
inhabits the warm springs of Iceland. The few species dis- 
covered by Miiller in Greenland are supposed to be peculiar : — 



Helix Pabricii. 
Pupa Hoppii. 
Vitrina angelicse. 



Succinea Groenlandica. 
Limmaea Valilii. 
,. ■ Pingelii. 



Limnsea Holbollii. 
Planorbis arcticus. 
Cyclas Steenbuchii. 



* The distribution of the Cycladidx is taken from the British Museum Catalogue, 
by M. Deshayes. 



GEKMAl^IC EEGION. 89 

1. Geemaitic Eegion: 

The whole of Northern Europe and Asia bounded by the 
Pyrenees, Alps, Carpathians, Caucasus, and Altai, constitutes 
but one province, with a fauna by no means proportioned in 
richness to its extent. * 

The land-snails amount to more than 200, but nearly all (or 
sit least five-sixths) are common to the Lusitanian region, f 



Helix 

Bulimulus 

Zua 


90 

10 


Pupa 

Clausilia 

Vitrina 


44 

62 

5 


Cyclostoma 

Acicula 

Limax 


1 

1 

9 




:] ' 


Succinea 

Balea 


5 

1 


Ai'ion 


4 


Cionella 


Carychium 


1 



The fresh-water shells belong to these genera and sub 
genera : — ■ 

Limnaea 20 Velletia 1 Unio, sp. and vara. ... 20 

Amphipeplea 2 Neritina, vars 3 Anodon, vars 20 

Physa 5 Paludina and BithjTiia 23 Alasmodon 3 

-Aplexa 1 Valvata 5 Cyclas 6 

Planorbis 16 Conovulus (Alexia)... 3 Pisidiuni 11 

Ancylus 7 Driessena 1 

According to Eeeve, there are 199 British molluscs, of which 
1.76 dwell on the land and 23 in the water. Of the species for- 
merly thought peculiar. Pupa anglica and Helix fusca have been 
Ifpund in France, and Helix lamellata in Holstein. Helix excavata 
(Bean) is still unknown upon the Continent ; and Geomalacus 
maculosus and Limncea involuta have only been met with in 
the south-west of Ireland, but are possibly Lusitanian species. 
\Dreisena jpolymorpha has been permanently naturalised in canals 
(p. 424), and Testacella Maugei and haliotidea in gardens; Bu- 
limus decollatus and Ooodalli have been often established in 
greenhouses. Some species are now very scarce in England 
that were formerly abundant, as : — 

Clausilia plicatula. Vertigo Venetzii. Succ!nea ohlonga. 

Vertigo minutissima. Helix lamellata Acicula fusca. 

Others, which occur in the newer tertiary deposits, have 
become quite extinct in England, such as : — 



* The mean temperature of the winter and summer months averages 36° — 57° ; in 
iWestern Europe autumn rains prevail, and summer rains in Eastern Europe and 
iSiberia. 

t It was the opinion of Professor E. Forbes that all the species of the Post-pliocene 
land of Northern Europe and Asia had origitiated beyond the bounds of that region. 



90 MANUAL OF THE MOLLUSCA. 

Helix fruticmn, living in France and Sweden. 

.. ruderata Germany. 

„ labyrinthica (Eocene) New England. 

Paludina marginata France. 

Corbicula consobrina Egypt and India. 

Unio littoralis France and Spain. 

On the other hand, some of the commonest living species 
have not been found fossil ; e.g. Helix aspersa, pomatia^ and 
cantiana. Several genera only occur fossil in the older ter- 
tiaries, viz. : — 



Glandina. 


Cyclotus. 


Nematura. 


Proserpina. 


Megalomastoma. 


Melania. 


Cylindrella. 


Craspedopoma. 


Melanopsis 



The following estimates have been made of the number 
of air-breathing molluscs inhabiting the various countries of 
Europe : — 

France, 202 (176 land, 26 fresh-water), Moquin Tandon. 



Dalmatia, 


202 (197 „ 5 


5> 


), Bellotti. 


Denmark, 


95 (72 „ 23 


J> 


), Morch. 


Norway, 


62 (36 „ 16 


>1 


), Martens and Friele. 


Finland, 


41 (23 „ 26 


5> 


), Nylander and Nordenskjbld. 


Lapland, 


16 (10 „ 6 


» 


), Wallenberg. 



This table seems to show that the Pulmonifera are most 
numerous in the warmest parts of Europe, and that their 
numbers decline, as far as species are concerned, as we ap- 
proach the Polar regions. Thus, in the Mediterranean area 
there are 800 species, in G-ermany 200, in Norway 50, in Lap- 
land 16. Hitherto, only 23 species have been obtained from 
European countries north of the Arctic circle. The most 
northerly species are Limncea palustris, Fhysa fontinalis, Physa 
hypnorum, and Succinea putris. 

Dr. Middendorff gives the following list of Siberian shells in 
his Sibirische Reise (Band II. th. 1. Petersb. 1851) : — 

Helix carthusiana, Irkutsk. Limnsea stagnalis, Bernaul, Irkutsk. 

Schrenkii, M. Tunguska, 58°.. „ palustris, „ „ 

hispida, Beresov. Bernaul. „ truncatula, „ Tomsk, 

ruderata, Stanowoj Mtn. „ leucostoma, Irkutsk, 

pura, „ Physa hypnorum, Bernaul ; TaimjTlande 

sub-personata, „; Ochotsk. Planorbis conieus, Bernaul; Beresov; 

Pupa muscorum, Bernaul. Kirgisensteppe, Altai. 

Zua lubrica, „ Planorbis complanatus, Altai. 

Succinea putris, „ ; Irkutsk. „ albus, Bernaul, „ 

Limnaea G-ebleri, M. Beniaul. „ contortus, „ 

„ auricularia, Nertschinsk. „ vortex, „ 

„ ovata, Bernaul. „ leucostoma, „ 

„ Kamtschatica, Mid. „ nitidus, Irkutsk. 

„ peregra, Bernaul, Beresov. Bithynia tentaculata, Bernaul, 



LTJSITANIAN KEGIOIf. 



91 



Bithynia Kickxii, E. Ami, Altai. 
Valvata cristata, var. Sibirica, Bernaul, 
Beresov; Kamtschatka. 
„ piscinalis, K. Ami. 
Unio complanatus Kamtschatka. 
„ Dahusicus, Mid. Scliilka. 
„ Mongolicus, M. Gorbitza, Dauria. 
Anodon herculeus, M. Scharanai. 



Anodon anatinus, Tunguska. 

„ cellensis var. Beringiana, Kamt- 
schatka. 
Cj'claa calj''culata, Bernaul, E. Lena, E. 

Ami, S. Kamts. 
Pisidium fontinale, Beresov. 

„ obliquum, Bernaul, Tomsk. 



2. LUSITANIAN EeGION. 

The countries bordering tlie Mediterranean, with Switzerland, 
Austria, and Hungary, the Crimea {Taurida), and Caucasus, 
form a great province (or rather cluster of provinces) to which 
Professor E. Forbes applied the term Lusitanian. The Canaries, 
Azores, and Madeira are outlying fragments of the same region.* 

In Southern Europe about 600 land- snails are found, of 
which above 100 are also spread over the Germanic region and 
Siberia ; and 20 or 30 are common to Northern Africa. Besides 
these 60 others are found in Algeria and Egypt, 100 in Asia 
Minor and Syria, and 135 in the Atlantic Islands, making a 
"total of nearly 900 species of Helicidoe.-f 

Of the 12 species of Zonites (proper) 10 are peculiar to 
Lusitania. 

The species of Bidimus, Achatina, and Pupa are small and 
minute, belonging to the sub-genera BuUmulus, Cionella, Zua, 
Azeca, Vertigo, &c. ; 4 (of which 2 are Algerian) have been 
referred to Glandina. 

In this region are also found 22 species of Cydostomidce and 
44 Limaddce: — 



Helix 392 

Bidimus 80 

Succinea 8 

Achatina 25 

Tornatellina 3 

Balea 4 

Pupa 120 

Clausiliat ,., 247 



Vitrina 11 

Daudebardia 3 

Helicolimax 3 

Limax 28 

Arion 7 

Phosphorax 1 

Testacella 2 

Parmacella 5 



CrjT)tella 1 

Cyclostoma 5 

Craspedopoma 3 

Pomatias 10 

Acicula , 4 

Caiychium 3 



The fresh-water are shells of the same genera as in the Ger- 
manic province, and the numbers about the same ; with the addi- 
tion of several species of Melania, Melanopsis, LitJioglyphus, and 
Cyrena. Melanopsis huccinoides is found in Spain, Algeria, and 

* In the South of Europe rain seldom falls in summer, but is frequent at other 
seasons, especially in winter. The mean temperature is 54° — 72". 

t The writer is greatly indebted to W. H. Benson, Esq., for information respecting 
the land-shells of the Lusitanian province, Afri,ca, and the remote islands. 

X Many of these cannot be considered species, in the sense here understood, but only 
as races, or geographical varieties. 



92 MANUAL OF THE MOLLTJSCA. 

Syria, having become extinct in tlie intervening countries. Two 
species of Lithoglyphus inhabit the Danube ; Cyrena {Corhicula) 
Panormitana is found in Sicily, two others in the Euphrates, 
and C. consohrina in the Alexandrian Canal. 

The Lusitanian province includes numerous minor regions, 
the islands and mountain tracts especially being centres or foci 
where a number of peculiar species are associated with those 
living around. Thus, of species not as yet recorded from other 
localities, Switzerland has 28, the Austrian Alps 46, Carpa- 
thians 28, North Italy and Dalmatia 100, Eoumelia 20, Greece 
and its Archipelago 90, Anatolia 50, Caucasia 20, Syria 30, 
Lower Egypt and Algeria 60, Spain 26, and Portugal 15 
HelicidcB and 9 Limacidw. 

Mediterranean Islands. 

Corfu, Cyprus, Ehodes, Syra, Candia, and Crete, have each a 
few peculiar land-snails, amounting to 40 species altogether. 

Balearic Isles. — Helix Graellsiana, hispanica (var. balerica), 
nyellii, minoricensis ; and Cyclostoma ferrugineum, common to 
Spain and Algeria. 

Corsica. — Helix Easpaili, tristis, Clausilia 4 sp. 

Sardinia. — Helix Sardiensis, meda, tenui-costata, Pupa 2, 
Clausilia 1. 

Malta has 2 peculiar species of Helix, and a Clausilia (scalaris). 

Sicily has 40 peculiar species of Helices and 3 Limaces. This 
island is connected with North Africa by a winding shoal with 
deep water on each side. 

Madeira Group. 

These ancient volcanic islands, 660 miles south-west of Por- 
tugal, consist of Madeira, with Fora and three other islets called 
Dezertas, and Porto Santo, 26 miles to the north-east, with the 
rocky islets Eerro, Baxo, and Cima.* The land-snails have 
been described by the Eev. E. T. Lowe,t and form the sub- 
ject of a monograph by Dr. Albers.J The investigations of 
Mr. Yernon Wollaston have nearly doubled the number of 
known species, which now amount to 134. The Vitrince belong 

* These islands, and also the Canaries and Azores, contain marine formations 
(volcanic grits and tufas) witli Miocene Tertiary shells. The islet of Baxo is quarried 
for lime. 

t Prunitise et novitise Faunae et Florae Maderae et Portus Sancti. 12mo. Lond., 1851« 
Descriptive list of all tlie species, by same aiitJior, Zool. Proc, for 1854, p. 161. The 
statements and numbei's given above are taken from this last monograph, corrected by 
2)ii\ WoUaston. 

4 Malacographia Maderensis, 4to. Berhn, 1854, with figures of all the species. 



LTJSITAWIAIir EEGIOJT. 



93 



to tlie section Helico-limax, tlie Cyclostomas to the sub-genus 
Craspedojpoma, and half the Pupas to Vertigo. 

Arion 1 Bulimus , 2 Cionella 3 Limnsea 1 

Limax 4 Glandina 4 Pupa 23 Ancylus 1 

Testacella 2 Azeca 3 Balea 1 Conovulus 3 

Vitrina 3 Tornatellina 1 Clausilia 3 Pedipes (afra.) ... I 

Helix 76 Zua 2 Cyclostoma 2 

Of the 92 found in Madeira or the Dezertas, 70 are peculiar ; 
54, of which 39 are peculiar, inhabit Porto Santo and its islets ; 
11 others, of which 4 are widely diffused, are common to.Madeira 
and Porto Santo. One species is peculiar to the Dezerta Grande; 
1 species and 1 variety to the southern Dezerta (Bugio) ; 1 to 
the northern (Gho) ; 1 variety to Perro. Seven species are 
common to the Dezertas ; 1 to the great and northern Dezertas ; 
6 to Madeira and Dezerta Grande ; and 3 to Madeira, Porto 
Santo, and the Dezertas. Of those species which inhabit more 
than one island, the specimens from each locality are recog- 
nisable as distinct races or geographichal varieties. Helix sub- 
plicafa and papilio are found on the Ilheo Baxo ; H. turricula on 
Cima. Of the total number (134) 112 species are peculiar to the 
Madeira group; 5 are common to the Canaries; 4 to the Azores, 
and one to the Guinea coast; 11 are common to Southern Europe, 
besides 2 Limnceids and 7 slugs, which may have been recently 
introduced, viz. : — 



Arion empiricorum. 
Limax variegatus. 

„ antiquorum. 

„ agrestis. 



Testacella Maugei. 
„ haliotidea. 



Helix cellaria. 

crystallina. 

pisana. 

pulchella. 

lenticula. 
( „ lapicida, fossil), 
Cionella acicula. 



Zua lubrica, var. 

„ folliculus. 
Bulimus decoUatus. 

„ ventrosus, Far. 
Balea perversa (p. 293). 
LinuiEea truncatula. 
Ancylus iluviatilis. 



Great quantities of dead shells of the land-snails are found in 
ancient sand-dunes near Cani9al, at the eastern extremity of 
Madeira, and in Porto Santo, including 64 of the living species 
and 13 which have not been, found alive. As the fossil examples 
of several species are larger than their living descendants, it 
is possible that some of those reputed to be extinct have only 
degenerated. It is a remarkable fact that some of the com- 
monest living species are not found fossil, whilst others, now 
extremely scarce, occur abundantly as fossils.* 

* Helix tiarella, W. and B., was supposed to be extinct, but in 1855 Mr. Wollaston 
detected it alive in tvro almost inaccessible spots on the north coast of Madeira : it is 
not a native of the Canaries. 



94 MANUAL OF THE MOLLTJSCA. 

Extinct Land-snails of Madeira, 

Helix delphinula, Lowe. M. 
„ arcinella, Lowe. P. 
„ coronula, Lowe. S. Deserta. 
vermetiformis, Lowe. P. 
Lowei, Fer. (porto-sanctana, var.?). P. 
fiuctuosa, Lowe (= chrysomela, Lowe), P. 
„ psammophora, Lowe (phlebophora var. ?). P. 
„ Bowdichiana, Fer. (punctulata, major?), M. P. 
Glaridina cylichna, Lowe. P. Santo. 
Cionella eulima, Lowe. P. 

Pupa linearis, Lowe. M. (= minutissima, Hartm?). 
* „ abbreviata, Lowe. M. 

The problem of the colonisation of these islands receives ad- 
ditional light from the circumstances noticed at other oceanic 
islands, especially the Canaries and St. Helena. There is evi- 
dence that this mountain group has not arisen newly from the 
sea, and great probability that it has become insulated by 
the subsidence of the surrounding land.* The character and 
arrangement of its fauna is probably nearly the same now as 
when it formed part of a continent, and the diminution of its 
land-shells in variety and size may be the result of a modern 
change of physical conditions brought about by human agency, 
as at St. Helena. The annual fall of rain is now 29 '82 inches, 
whereas it was remarked by Columbus, three hundred and fifty 
years ago, "that, formerly, the quantity of rain was as great in 
Madeira, the Canaries, and the Azores, as in Jamaica, but since 
the trees which shaded the ground had been cut down, rain had 
become much more rare.f 

The Azores are a group of 9 volcanic islands, 800 miles west 
of Lisbon, the loftiest being Pico, 7,613 feet. The number of 
land- shells have been recently increased to 68 by Morelet and 
others, — including Limax 4, Arion 3, Testacella 1, Vitrina 7, 
Helix 30, Bulimus 10, Zua 1, Pupa 8, Balea 1, Auricula 3. Of 
these 28 are found in Europe, 7 in Madeira, 4 in the Canary 
Islands, and the remaining 29 are peculiar. 

The Canary Islands are sixty miles west of Africa, with a 
temperature of 60°— 66' in the coolest half year, and 78°— 87® 
in the hottest. The land- snails are about 80 in number, in- 
cluding Helix 50, Nanina 1, Vitrina 3, Bulimus 16, Achatina 3, 
Pupa 5, Limax 1, Phosphorax 1, Testacella 2, Cryptella 1, and 

* See the observations of Mr. James Smith, and of Sir C. Lyell and Mr. Hartung 
(Geol. Joui-. 1854). 

t Cosmos, ii. 660, Bohn ed. It seems likely that Jamaica itself has since undergone 
a similar change ; the fall of rain is stated to be 49 12, whilst in the neighhotuing 
islands it exceeds 100 inches. 



LTJSITANIAN EEGIONi 95 

4 Cydostomidce. Of these, 60 are peculiar, 12 are common to 
Southern Europe, and 4 to the "West Indies ? 1 to Morocco, 1 to 
Algeria (also European), and 1 to Egypt. The fresh-water 
shells are Physa 2, Ancylus 1. 

Helix ustulata and McAndrei are peculiar to the rocky islets 
known as the " Salvages," north of the Canaries. 

The absence of Western African land-shells, and the presence 
of West Indian species may be explained by the currents which 
come from the Antilles, as shown on the map.* Some of the 
European species may have been introduced {e.g., Helix lactea, 
pisana, cellaria) ; but the presence of 20 Lusitanian species, in a 
total of 80, is too remarkable to be accidental. 

The Cape de Verde Islands, although much farther to the south, 
are also much farther from the continent, being 320 miles west 
of Cape de Yerde ; the mean temperature is Go'^' — 70*^, and the 
vegetation, as Dr. Christian Smith remarked, is more like that 
of the Mediterranean coast than West Africa. Of the 12 land- 
shells, two are common to the Canaries and Azores. 

Lusitanian Species of Wide Bisfrihution. 
Helix amanda, Sicily — Palma. 

„ planata, Morocco — Canaries. 

„ lenticula, S. Europe — Madeira — Canaries. 

„ rozeti, Sicily, Morea — Algeria — C. de Verde — Canaries, 

„ lanuginosa, Majorca— Algeria— Palma. 

„ simulata, Syria — Egypt — Lancerotte. 

„ Michaudi, summit of Porto Santo — Teneriffe ? 

„ C3''clodon, Azores — Canaries— C. da Verdes. 

„ advena, (= erubescens Lowe), Madeira — Azores— St. Vincent. 

„ pUcaria and planorbella, Canaries— Porto Eico? 
Bulimus subdiaphanus. Canaries — Azores — C. de Verdes. 
„ bcEticatus and badiosus, Canaries — St. Thomas ? 

Ascension. — This barren volcanic island, in the midst of the 
Atlantic Ocean, is not known to possess any terrestrial Pulmoni- 
fera beside a slug, the Limax Ascensionis. Mr. Benson thinks 
that some Helicidce might possibly be found on the Green 
Mountain, 2,840 feet high, where the garrison have their gar- 
dens. Mr. Darwin remarks ' ' we may feel sure that at some 
former epoch, the climate and productions of Ascension were 
very different from what they now are." 

St Helena (No. 28 of Map). 

The island of St. Helena is 800 miles S.E. of Ascension, and 

1200 from the nearest African coast of Benguela. It is entirely 

* Long before the discovery of America it was observed that the westerly gales 
washed ashore stems of bamboos, trunks of pines, and even living men in canoes. — 
Humboldt, ii. p. 462. 



96 MANIFAX OF THE MOLLUSC A. 

volcanic. The indigenous plants are all peculiar, and not more 
related to those of Western Africa than to Brazil.* The land 
shells are also peculiar ; 13 species have been described, viz. • — 
Helix, '^ sp, Bulimus 5, Achatina 2, Pupa 1, Sicccinea [Helisiga) 
2. As many more have been met with only in the condition of 
dead shells, rarely retaining their colour and translucency. 
They are found beneath the surface-soil in the sides of ravines 
worn by the heavy rains, at a height of 1,200 to 1,700 feet. 
" Their extinction has probably been caused by the entire de- 
struction of the woods, and the consequent loss of food and 
shelter, which occurred during the early part of last century." 
(Darwin's Journal, p. 488.) A living Bulimus, related to the 
extinct B. Blofieldi, is found feeding on the cabbage-trees, only 
on the highest points of the island. 

Extinct Land-shells of St. Helena.-f 

Bulimus auris vulpinus. Bulimus relegatus. 

„ Darwini. Helix bilamellata. 

„ Blofieldi. „ polyodon. 

„ Sealei. „ spurca. 

„ subplicatus. „ biplicata. 

„ terebeHum. „ Alexandri. 

„ fossilis. Succinea Bensoni. 

The large Bulimus, (fig. 123, p. 291), has no living analogue in 
Africa, but is a member of a group characteristic of tropical 
America (to which the names Plecocliilus, Pachyotis and Caprella 
have been given), including B. signatus, B. hilahiatus, B. goni- 
ostomus, and especially B. sulcatus (Chilonopsis, Fischer) of St. 
lago.J The four next species belong to the same type, but are 
smaller and slenderer. " The marine mollusks of the coast of 
St. Helena would lead us to infer the very ancient isolation of 
that island, whilst at the same time a pre-existing closer 
geographical relationship between the African and the American 

* " It might perhaps have been expected that the examination of the vicinity of the 
Congo would have thrown some light on the origin, if I may so express myself, of the 
Flora of St. Helena. This, however, has not proved to be the case ; for neither has a 
single indigenous species, nor have any of the principal genera characterising the 
vegetation of that island, been found either on the banks of the Congo, or on any other 
part of this coast of Africa." — R. Brown, Appendix to Captain Tuckey's Narrative of 
the Congo Expedition (p. 476). 1818. 

t Gr. Sowerby in Darwin's " Volcanic Islands," p. 73. Forbes, Joum. Geol. Soc. 
1852, p. 197.— Benson, An. Nat. Hist. 1851, vii. 263. 

X As Dr. Pfeiffer includes this (with a sign of doubt) amongst the synonjons of 
£. auris-vulpinus, he must have suspected that the specimens came from St. Helena 
and not from St. lago. The only other group of Bulimi resembling the St. Helena 
shells occurs in the Pacific Islands : — Bulimus Caledonicus at Mulgi'ave I., B, aims 
zcuince at the Solomons, and B, shongi in New Zealand. 



CAPE REGIOK. 97 

continents than now maintains is dimly indicated. Tlie infor- 
mation wo have obtainpd respecting the extinct and existing 
terrestrial mollnsks would seem to point in tlio same direction, 
and assuredly to indicate a closer geographical alliance between 
St. Helena and the east coast of S. America than now holds." 
(Forbes.) 

Tristan d^Acunha (No. 29 of Map). 

Two peculiar species of Balea (Tristensis and ventricosus) are 
found on this remote and lofty island, which attains an eleva- 
tion of 8,236 feet. 

3. African Eegion. 

Tropical western Africa, with its hot swampy coasts and river 
valleys is the region of the gYQdA> Achatince and Achatina-like 
BuUmi, the largest of all living land-snails. In 1863 the 
numbers known were — Vitrina 4 sp., Streptaxis 7, Helix 30, 
Pupa 5, Bulimus 50, Achatina 54, Succinea 3, and Perideris 18. 
Streptaxis Reduziana inhabits the Gruinea Islands. Helix Folini, 
Bulimus numidicus smd fastigiatus, Pupa crystallum and sorghum, 
Achatina columna, striatella, and lotophaga are found on Princes 
Island ; Pupa putilla on Goree Island ; Bulimus (Pseudachatina) 
Downesi, Achatina iostoma and Glandina cerea at Fernando Po. 
The reversed river-snail [Lanistes) is generally diffused in the 
fresh waters of Africa ; several species of Potamides and Vihex 
are found in the embouchures of the western rivers and Pedipes 
on the sea-shore. The fresh-water bivalves of Senegal are 
similar to those of the Nile : — 

Pisidium paravsiticum, EgjT)t. Iridina exotica, Senegal. 
Cyrenoides Duponti, Senegal. „ rubens ,, 

Corbicula, 4 sp. Egypt. Pleiodon ovatus „ 

Iridina nilotica „ ^theria semUunata „ Nile. 

„ aegyptiaca „ Galatea radiata „ 



4. Cape Eegion. 

Dr. Krauss describes 41 species of land-snail from South 
Africa, and Mr. Benson has furnished a list containing 22 
others ; these are all peculiar, except a Succinea, which appears 
to be only a variety of the European S. putris, and two Euro- 
pean Helices (H. cellaria smd pulchella) probably imported to the 
environs of the Cape. In 1863 they had raised the number to 
about 90. Jhere are also 3 slugs, 9 freshwater Pulmonifera, 7 
marine Pulmonifera, 5 freshwater bivalves, and 5 univalves. 



98 MAKITAL OF THE MOLLUSCA. 

The species found at the Cape, Algoa Bay, Natal, &c., are for 
the most part different — Potamides decoUatus, CUondla ainuatay 
and an Assiminea inhabit brackish waters. 

Limax 4 

Arion 1 Limnsea 1 Paludina 3 

Physa 4 Neritina 1 

Vitrina 4 Physopsis 1 

Helix 35 Ancylus 1 CorMcula 

Succinea 4 Planorbis 3 Cyclaa , 

Bulimus 13 Pisidium , 

Pupa 6 Vaginulus 1 Unio , 

Achatina 7 Oncidium 1 Iridina 

Cyclostoma 6 Auricula 6 

5. Yemen — Madagascar. 

The S. W. Highlands of Arabia (Yemen) form a distinct 
Botanical province isolated by rainless deserts to the north. 
The land snails consist of a few species of Helix and BuUmus, 
Cyclostoma lithidion, and 3 species of the section Otopoma, a 
group also found in Madagascar. Two species are common to 
the island of Socotra (No. 30), which also has a species (of Fupd) 
common to Madagascar. BuUmus guillaini, Cyclostoma gratuw^ 
modestum and Souleyeti are found on the island of Abd-el-Gouri. 

Yery few land shells have been collected on the mainland of 
Eastern Africa, although it is a rainy region, and well wooded 
in the southern part ; 5 species only are recorded from Moga- 
doxa and Ibu, belonging to the genera Helix, Bulimulus, Acha- 
tina, Pupa, and Otopoma. On the Island of Zanzibar are found 
Achatina Rodatzi and allisa, Cyclostoma Creplini and Zangue- 
harica ; Pupa cerea is common to Zanzibar and Madagascar. 

Madagascar itself is rich in land shells ; Dr. Pfeiffer enume- 
rates — Helix 28 sp., BuUmus 6, Succinea 14, Pupa 1, Achatina 4 
(one of which, eximia, is allied to A. Columna, of W. Africa), 
and 32 Cyclostomidce, chiefly of the section with spiral ridges 
{^Tropidophora), 3 of the division Otopoma. Cyclostoma carini- 
ferum and Cuvieri are found on the Island of Nosse Be ; Helix 
guillaini on S. Maria I. Amongst the fresh- water shells are 
Melania amarula, Melanatria fluminea, and Neritina corona. 

The land shells of the Mascarene Islands are nearly all pecu- 
liar; we are indebted to Mr. "W. H. Benson for most of the 
information existing in respect to them. 

Comoro Islands. 

Helix russeola and Achatina simpularia are found in Mayotte ; 
Cyclostoma pyrostoma in Mayotte and Madagascar. 



INDIAN EEGION. 

Seychelles (No. 31 of Map). 

Parmacella Dussumieri. Bulimus omatus. 

Helix unidentata. „ fulvicans. 



99 



„ Studeri. 




Cyclostoma insulare. 


„ Souleyeti. 






„ pulchrum. 


„ Tranquebarica. 




Cyclotus conoideus. 


Streptaxis Souleyeti. 










Mauritius (32). 




Parmacella perlucida. 


Helix Barclayi. 




Pupa Largillierti. 


„ Eangii. 


„ odontina. 




Cyclostoma Barclayi. 


„ mauritii. 


Vitrina angularis. 




„ Michaudi. 


Helix phil3Tina. 


Tornatelliiia cernica. 




„ carinatum. 


„ inversicolor. 


Gibbus Antoni. 




„ undulatum. 


„ stylodon. 


„ Lyonneti. 




„ insulare ? 


„ mauritiana. 


Succinea sp. 




Cyclotus conoideus ? 


„ mauritianella. 


Bulimus clavulinus. 




Otopoma Listeri. 


„ rawsoni. 


„ Mauritianus. 




„ lisemastoma. 


„ semicerina. 


Pupa pagoda. 




Eealia rubens. 


„ mucronata. 


„ fusus. 




„ aurontiaca. 


„ nitella. 


„ sulcata. 




„ multilirata. 


„ rufa. 


„ clavulata. 




„ expansilabria. 


„ similaris. 


„ modiolus. 




„ globosa. 


„ suffulta. 


„ funicula. 




Megalomastoma croceum 


„ albidens. 


„ versipolis. 







Two large species of Achatina [fulica and panthera) abounding 
in the coffee plantations, are believed to have been introduced. 
The annual fall of rain in Mauritius is 35'25 inches. 





Bourhon (No. 33). 


Helix ceelatiu-a. 


HeUx tortula. 


„ detecta. 


„ Brandiana. 


„ deKbata ? 


Pupa Largillierti— Mauritius. 



Rodriguez. 
Cyclostoma articulatum, Madagascar ? Streptaxis — ^pyriformis. 

No. 34. Kergueleri's Land. Helix Hookeri was collected at 
this island when yisited by the Antarctic Expedition. 



6. iKDIAJSr Eegion. 

Proceeding eastward, in Asia, the species of Achatina, Pupa, 
Clausilia, Fhysa, Limax, and Cyclostoma rapidly diminish or 
quite disappear. Helices of the section Nanina become plenti- 
ful, amounting to 150 species, and Bulimulus and Cyclophorus 
attain their maximum. Leptopoma, and Pupina are peculiar to 
the Asiatic Islands. 

Our catalogue of Indian land shells must be very imperfect, 
including only about 180 Helicidce and 50 Cyclostomidce. A very 

e2 



100 MANUAL OF THE M0LLT7SCA. 

few of the Indian species are common to Cliina and tlie Asiatic 
Islands, or even to Ceylon. The shells of northern India 
resemble those of the Lusitanian region ; in the south they 
approximate more to the large and vividly coloured species of 
the Asiatic Islands. In the Himalaya land shells are numerous, 
and ascend as high as the region of Junipers and Ehododen- 
drons, 4,000 — 10,000 feet above the sea. 

Helix 83 Pupa 7 Cyclopliorus 26 

Nanina ...46 Clausilia 7 Leptopoma 1 

Ariophanta 8 Vitrina 9 Pterocyclus 10 

Streptaxis 3 Succinea 7 Cj'clotus 3 

Bulimus 45 Parmacella 2 Megalomastoma 4 

Achaiina 16 Cyclostoma 3 Diplommatina 3 

Parmacella and Vaginulus are found in India, and the typical 
fresh-water species of Oncidium. Ordinary forms of Limncea 
and Planorhis are abundant, and there is one species of Ancylus. 
Physa occurs only in a fossil state, or is represented by the 
singular Camptoceras of Benson. Hypostoma Boysii, Auricula 
Judce, and Polydonta scarahceus are also Indian forms. 

The gill-breathing fresh- water shells of India are very 
numerous, especially the Melanias and Melanatrias, and species 
ofPirena, Paludomus, Hemimitra (retusa), ATnpullaria, Paludina, 
Pithynia, Nematura (deltse), Assiminea (fasciata), Neritina (par- 
ticularly crepidularia and Smithii) and Navicella (tessellata). 

The brackish-water species of Cerithidium, Terebralia, and 
Pyrazus are mostly common to India and North Australia. 

The fresh-water bivalves are a few ordinary forms of Unio, 
3 species of Cyrena, a Corhicula (of which 6 species have been 
made), Cyclas Indica, Area scaphula, Glaucomya cerea, and Nova- 
culina gangetica. 

Ceylon. The land-shells of Ceylon have been investigated by 
Mr. Benson ; they most resemble those of the Neilgherry hills, 
but are nearly all specifically distinct, and even some of the 
genera are peculiar. It seems entitled to rank as a province. 
Helix Waltoni and SJcinneri, are examples of the most charac- 
teristic form of Helices ; the Yitrini-form type [Nanina) is also 
common. H. hcemastoma, one of the most conspicuous species, 
found on trees at P. Galle, is common to the Nicobar Islands. 
The Achatinas belong to a distinct section {Leptinaria, Beck), 
also represented on the Continent. Some of the Bulimi approach 
the Philippine forms. 

Helix 46 Succinea 1 Pterocyclus 5 

Nanina 9 Pupa 3 Aulopoma 4 

Vitrina 3 Achatina 8 Leptopoma 5 

Streptaxis 2 Cyclophorus 12 Cataulus 10 

Bulimus 13 



PHILIPPINE ISLANDS. 101 

The fresli-water shells belong to tlie genera Limnsea, Pliysa, 
2 species (not found on the Continent) ; Planorbis, Melania, 
Tanalia 10 (peculiar), Paludomus, Bithynia, Ampullaria, Neri- 
tina, Navicella, Unio, and Cyrena. 

At the Nicobar Islands are found — Cataulus tortuosus, Heli- 
cina Nicobarica and Pupina Nicobarica. Helix castanea is from 
Sumatra. (Beck.) 

v. Chesta aio) Japais". 

The few land- snails known from China are of Indian and 
Lusitanian types ; viz. — Helix 20, Nanina 10, Streptaxis 1, 
(Cochin- China), Bulimus 5, Achatina 2, Pupa 1, Clausilia 11, 
Succinea 1, Eelicarion 6, Cyclophorus 1, Cyclotus 1, Otopoma 1. 
In the Island of Chusan Dr. Cantor discovered the genera 
Lampania and Incilaria, The most characteristic bivalves are 
Glaucomya Sinensis, and Symphynota plicata ; 3 species (or 
varieties) of Cyrena and 9 Corbiculas are described by Deshayes, 
and a Flanorhis by Dunker. 

In the Japanese and Loo-choo Islands only 9 species of Helix, 
2 of Nanina, 2 of Clausilia, and 2 of Helicarion have been 
hitherto obtained. 

8. Philippine Islands. 

The extraordinary richness of these islands has been developed 
mainly by the researches of Mr. Cuming. The Helicidce (above 
300) are inferior in number only to those of Lusitania and the 
Antilles, and vastly superior in size and beauty of colouring. 
The Cydostomidce (55) are not much fewer than in India. Nearly 
all the species are confined to particular islands, and the repeti- 
tion of forms makes it probable that many of them are geogra- 
l j phical varieties. The climate is equable, with a temperature 
,i like that of South China (66° — 84°), woods are prevalent and 
I j the rains heavy — all circumstances favourable to the individual 
I abundance of land-snails. 

i| Helix 160 Clausilia 1 Cj^clotus 6 

i: Nanina; 40 Vitrina 18 Megalomastonaa 1 

Helicarion? 3 Cyclopnorus 15 Pupina 9 

Bulimus 105 Leptopoma 16 Helicina 7 

The Helices belong in great part to the section CaUicochUas 
(Ag.) and Helicostyla (mirabilis) Per. Some with sharply-keeled 
whorls have been called Geotrochi (Iberus of Albers). The 
Bulimi are chiefly of the section Orthostylus (Beck), large and 



102 MANUAL OF THE MOLLUSCA. 

highly coloured, with a hydropTianous epidermis, the hands he- 
coming translucent when wetted ; others, like the well-known 
B. perversus, represent the typical Brazilian forms. To these 
islands belong most of the helicina-shaped Cydophori {Lejpto- 
poma.) 

The fresh- water shells are numerous; above 100 were obtained 
by Mr. Cuming, including many species of Melania (54 ?), Navi- 
cella lineata, and suhorhicularis, 5 species of Glaucomya, TJnio 
verecundus, a Corhicula, and 11 sp. (?) of Cyrena. 

Celebes and Moluccas. Prom these islands we have on record, 
at present, 16 species of Helix, Nanina 19, Bulimus 3, Yitrina 
2 (viridis and flammulata, Quoy), Cyclophorus 1. In the 
fresh-water ponds and rivulets Mr. A. Adams found species of 
Melania, Assiminea, Ampullaria, and Navicella ; Auricula 
subulata and Conovulus leucodon. Neritina sulcata was found 
on the foliage of trees several hundred yards from the water. 

9. Java. 

The Java group, ijicluding Eloris and Timor, have been par- 
tially explored fron?. the head- quarters of the Dutch settlement 
at Batavia. The land and fresh-water shells are nearly all 
peculiar, a few only being common to the Philippines and North 
Australia ; they have been described and figured by M. Albert 
Mousson (8vo. Zurich, 1849, 22 plates). 

Helix 15 Platj'closter ? 3 Navicella 2 

Nanina 8 Meghimatium 2 

Ariophanta 1 Unio and i 

Bulimus 10 Limngea'. 1 Symphynota f 

Clausilia 6 Auricula 2 Alasmodon 2 

Cyclophorus 4 Anodon 1 

Cyclotus 2 Melania 5 Cyrena 7 

Leptopoma 1 Ampullaria 1 Corbicula ,,.,. 4 

ParmaceUa 3 Neritina 2 

10. Borneo. 

The land shells of this great island are almost unknown, and 
the only reason for mentioning it separately is the doubt whether 
it should be considered part of the Javanese Province, or asso- 
ciated with the Moluccas and Philippines. 

Helix 12 Paxillus 1 Leptopoma 3 

Nanina 8 Succinea 2 Cyclotus 1 

Bulimus 1 Cyclophorus 2 Pterocyclus 2 

The fresh- water bivalves are Grlaucomya rostralis, Corbicula 
tlimida, and Cvrena triangularis. JPholaa rivicola was found 



I 



ATTSTEALIAN EEGION". 103 

burrowing in floating logs used as landing places, 12 miles from 
th.e sea, up the Pantai river. The mangrove swamps abound 
with Cerithidium, Terebralia Telescopium, Potamides palustris, 
and Quoyia ; Auricula Midae and Polydonta scarabaeus inhabit 
the damp woods. 

11. Papua A2to New Ibelajstd. 

The land shells of New Guinea are nearly all distinct from 
those of the Philippines and Moluccas, and include some related 
to the Polynesian types. The Louisiade Islands to the south- 
east and New Ireland on the north of New Guinea are included 
with it. 

Helix 30 Partula 3 Leptopoma 1 

Nanina 7 Pupina 3 Cyclotus 1 

Bulimus 2 Otopoma 1 Helicina 2 

Cyrence are numerous in this region. Cyclostoma australe is 
common to the Australian Islands and New Ireland ; C. Massence 
to Australia and New Guinea, and C. Vitreum to New Ireland, 
New Guinea, the Philippines, and India. 

12. AUSTEALLAN" EeGION. 

Both fauna and flora of Tropical Australia are distinct from 
those of New South Wales and Tasmania, the principal barrier 
being the desert character of the interior ; but the localities of 
the land shells have not been defined with sufficient accuracy to 
show whether they are equally distinct. The most complete list 
is given by Prof. E. Porbes, in the Appendix to McGillivray's 
Narrative of the Yoyage of H.M.S. Eattlesnake (1846-50) ; it 
specifies 48 Helices (of which H. pomum is the most conspicuous), 
10 Bulimi, an Achatina, 6 Yitrinas {Helicarion) belonging to the 
mainland, and one from the Lizard Islands, and a dextral Balea 
(australis). Pupa and Helicina {Gouldiana) are only found on 
the islets off the north-east coast, and Pupina {bilinguis) at Cape 
York and the adjacent islets ; a portion of the province which is 
densely wooded, and lies within the rain region of the Asiatic 
Islands. Cyclostoma hilahre of Menke's Catalogue is probably 
West Indian. The fresh- water shells of Australia are Flanorhis 
Gilberti, Jridinae? (YictoriaE.), Unio auratus, cucumoides, super- 
hus [Ryridella), australis, Corhicula 4 species, Cyrena 3, Cyclas 
egregia (Hunter E.), Pisidium semen and australe, the last common 
to Timor. 

More recently Cox has described 178 species, belonging prin- 



104 MANUAL OF THE MOLLUSCA. 

cipally to East Australia. He notices, Helix 133, Vitrina 17, 
Succinea, 12, Bulimus 17, Pupa 6, Balea 1, and others belonging 
to genera Triboniophorus, Limax, and Planorbis. 

13. South Austealia aito Tasmania. 

From extra-tropical Australia we have the following : — 
Helix 9, Helicarion 2, Bulimus 2, Succinea 1 (common to Swan 
Eiverand Tasmania), Limax olivaceus, and one Ancylus. Two 
of the largest land snails, Helix Cunninghami and Falconeri, are 
found in New South Wales. The coasts of this region are 
thinly wooded, but much of it is rendered desert by want of 
rain ; in New South Wales droughts recur at intervals of twelve 
years, and sometimes last three years, during which time scarcely 
any rain falls. 

14. New Zealand. 

The moist and equable climate of these islands (which have a 
mean temperature of 61° — 63*^) is favourable to the existence of 
numerous land-snails. Nearly 100 species of land and fresh- 
water shells are already determined, and are all peculiar ; the 
genus Helix musters 60 species, some of which, including the 
great H. Busbyi, resemble in shape the European Helicellae ; 
Bulimus 3, Balea (peregrina), Yitrina 2 of peculiar form, Tor- 
natellina 1, Cyclophorus cytora, and Omphalotropis egea. 
There are two slugs, Limax antipodarum and Janella bitenta- 
culata ; two fresh-water pulmonifera, Physa variabilis and Latia 
neritoides ; several marine air-breathers,— -Oncidium [Peronia] 2, 
Siphonaria 3, Amphibola 1 {avellano). The other fresh- water 
shells are Melanopsis trifasciatus (a Lusitanian type), Assiminea 
antipodarum and Zelandise, Amnicola ? corolla, Cyclas Zelandise, 
and TJnio Menziesii and AucMandicus. 

Vitrina zehra is found at the Auckland Islands. 

15. Polynesian Eegion. 

The Pacific Islands are partly the volcanic summits of sub- 
merged mountain ranges, usually fringed or surrounded with 
coral reefs ; and partly atolls or lagoon islands, scarcely rising 
above the sea, and presenting no vestige of the rock on which 
they are based. The low coral islands form a long stream of 
archipelagos, commencing in the west with the Pelews, Caro- 
lines, Eadack, Gilbert, and EUice groups, then scattered over a 
•vHder space, and ending eastwards in the Low Archipelago : 



POLYNESIAN- EEGION. 105 

they are chiefly, perhaps entirely, colonised by drift from the 
other islands. 

The volcanic groups are the Ladrones, Sandwich Islands, and 
Marquesas, to the north of the low coral zone ; and to the south 
of it, the Salomons, New Hebrides, New Caledonia, andFeejees 
— the Friendly Islands, Navigator's and Cook's Islands — Society 
and Austral Islands, ending with Pitcairn's and Elizabeth 
Island. Many of these are very lofty. Their moUuscan fauna 
is entirely peculiar, but it has most affinity with those of New 
Zealand and the Asiatic Islands, and great analogy with those 
of St. Helena, Brazil, and the West Indies. 

Salomons — New Hebrides — New Caledonia— Feejees. 

The most remarkable land- shells of these islands are the great 
auriculoid, Bulimi (e.g. B. auris-hovince and B. miltochlius of 
the Salomons). Acicula striata and 2 sp. of Cyrena are found 
at Yanicoro ; and Physa sinitata, Peronia acinosa and corpulenta, 
and several Neritinas and coronated Melanias, have been ob- 
tained at the Feejees.* 

Helix 18 Bulimus 10 Cyclophqrus 2 

Nanina 2 Partula 6 Omphalotropis 1 

Vitrina 6 Acicula 1 Helicing, 6 

Friendly Islands — Navigator's — Society Islands. 

The principal lofty and rocky islands of the southern Pacific, 
at which land shells have been obtained, are Tonga, Samoa, 
TJpolu, and Manua ; Tahiti, Oheteroa, and Opara ; Pitcairn's 
Island and Elizabeth Island. Each appears to have some pecu- 
liar species and some common to other islands ; the little raised 
coral islet Aurora {Metia), north-east of Tahiti, 250 feet in ele- 
vation, has four land-snails which have been found nowhere 
else — Helix pertenuis, doedalea, Partula pusilla, Helicina trochlea. 
" Samoa and the Friendly Islands must have intimate geo- 
logical relations ; the same forms, and many of the same species 
of land shells, occur on both groups ; not a single Feejeean 
species was collected on either." (Gould.) 

Helix 13 Tomatellina 6 Cyclophorus 5 

Nanina 18 Pupa 3 Omphalotropis 6 

Bulimus 1 Succinea 12 Helicina , 13 

Partula 15 Electrina 1 

The fluviatile shells are species of Physa, Melania, Assiminea 

* The Feejees {Viti) are more nearly allied to the westward islands, such as the 
New Hebrides, than the Friendly Islands. Succinea and Partula, so plentiful at the 
latter, are not found at the Feejees. (Gould, U.S. Exploiing Expedition). 

f3 



106 MANUAL OF THE MOLLTJSCA. 

{Taheitana) Neritina, and Navicella ; the two last being often 
littoral, or even marine, in their habit. 

Low Coral Islands. 

The Atolls, or lagoon-islands, are less prolific : 2 Helices and 
2 Partulm are found at Oualan, in the Caroline Archipelago ; 
and from Chain Island [Annaa), the centre of commerce in the 
eastern Archipelago, have been obtained— ^eZt'cc 2 sp., Nanina 1, 
Fartula 1, TomatelUna 1, Gydophorus 1, and Melarripus mucrO' 
natus. 

Sandwich Islands. 

The land shells of these islands exceed 200, and are all, or 
nearly all, peculiar : there is one Limax ; and in the fresh waters 
are found Limncea volutatrix, Physa reticulata (Gould), Neritopsis ? 
Neritina Nuttalli and undata, and Unio contradens (Lea). 

In the I. Kaui, two species of Achatina have been found : 
the Achatinellse are elongated {Leptachatina, Q-.) and the Helices 
planorboid and multispiral. In Molokai the Achatinellse are 
large and coloured. In Maui and Oahu the Helices are small 
and glabrous, or hispid, ribbed, and toothed. In Hawaii, Suc- 
cineas prevail, and Achatinellae are rare. (Grould.) The large 
number of Achatinellae is partly due to this group having been 
specially studied by Judge Cooper of America. 

Helix 20 Achatina 5 Pupa 2 

Nanina 5 Achatinella 204 Vitrina 2 

Bulimus 5 Tomatellina 3 Succinea 10 

Partula 4 Balea 1 Helicina ..,,, 6 

The Island of Guam, Ladrones, has 3 sp. of Partula, 2 of 
Achatinella, and 1 Omphalotropis. At the Marquesas have been 
found 3 sp. of Nanina, 1 Partula, and X Helicina, 

NEW WOBLD. 
16. Canadian Eegion. 

The country drained by the Great Lakes and the river St. 
Lawrence possesses very few peculiar shells, and these mostly 
of fresh-water genera. It is chiefly remarkable for the presence 
of a few European species, which strengthen the evidence before 
alluded to (p. 60) of a land- way across the north Atlantic 
having remained till after the epoch of the existing animals and 
plants.* 

* For example, the common Heather ( Ca^/wwa vulgaris), one of the most abundant 
social plants of Europe, characteristic of the moorland zone, and seldom rising above 



ATLANTIC STATES. 107 

Helix hortensis (imported), coast of New England and banks of St. Lawrence. 

„ pulchella (smooth var. only), Boston, Ohio, Missouri. 
Helicella ceUaria (glaphyra, Say ?), N. E. and middle States. 

„ pura, nitida, and fulva? 
Zua lubrica. North West Territory. 
Succinea amphibia (= campestris, Say?). 
Limax agrestis (= tunicatus, G-.), Mass. 

„ liavus, New York, introduced. 
Vitrina pellucida ( = Americana ?) Limnsea palastria (= elodes, Say P). 
Arion hortensis. New York (Dekay.) „ tnmcatula (= desidiosa?). 

Aplexa bypnorum (= elongata, Say?), 
Auricula deticulata, Mont., New York Harbour. 
Alasmodon margaritiferus (= arcuatus, Barnes). 
Anodon cygneus (= fluviatilis, Lea?). 

The shells proper to Canada, or derived from the adjoining 
States, are only 6 sp. of Helix, 2 Succineas, and 1 Pupa; 8 sp, 
of Cyclas have been obtained from the region of Lake Superior. 

The following species occur in New England : — 

Helix 13 Physa 2 Unio 5 

Succinea 2 Planorbis 11 Alasmodon 2 

Pupa 7 Paludina 1 Anodon 2 

Limneea 7 Valvata 2 Cyclas 6 

Ancylus 2 Auricula 1 Pisidium I 

Carychium exiguum, Say, is found in Vermont, and Limncea 
(Acella) gracilis in Lake Champlain ; Valvata tricarinata and 
Faludina decisa a,re characteristic forms. 

The genera Clausilia and Cyclostoma are entirely wanting in 
Canada and the Northern States. The Limacidce are represented 
by Fhilomycus, of which there are 9 reputed species, ranging 
from Massachusetts to Kentucky and South Carolina. 



17. Atlantic States. 

The parallel of 36'' N. lat. forms the boundary-line of two 
botanical regions in the United States ; but the evidence of the 
fresh- water shells, in which they are particularly rich, seems 
to favour a division into two hydrographical provinces — ^the 
region of the Atlantic streams 9,nd the basin of the Mississippi. 
About 50 fresh- water Pulmonifera, 150 pectinihranchiata, and 
250 bivalves, are reputed to be found in the States, and it is 
supposed that only a few species are common to both sides of 
the Alleghanies. Cyclas mirahilis, Pisidium Virginicumy Gyrena 

3,000 feet on the mountains of Scotland. (Watson.) According to Pallas it abounds 
on the western flanks of the Ural Mountains, but disappears on their eastern side, and 
is not found ia Siberia. In the Pliocene period it appears to have spread itself north- 
ward and westward to Iceland, Greenland, and Newfoundland, where it stiU grows, 
the only heath indigenous to the New World. (Humboldt.) 



108 MABTTAL OF THE MOLLTTSCA. 

Carolinensis, and Unio complanatus and radiatus, are cliaracter- 
istic of the eastern rivers; Melania depygis is said to be the 
only member of that large genns found eastward of the Hudson 
Eiver. Of the American land-snails, 29 sp. of Helix, 6 Suc- 
cineas, and 13 Pupas are enumerated from the Atlantic States. 
In Florida the propinquity of the West Indian fauna is strongly 
indicated by the occurrence of the great Olandina truncata, by 
species of Cylindrella, and a Helicina. A Cuban species of 
Chondrojpoma (0. dentatum) is also said to occur in Florida, and 
Ampullaria depressa in Florida and Georgia. 

The Pulmonifera of North America have been carefully exa- 
mined by Messrs. Binney,* Bland, f and others. The following 
summary of North American PwZmowt/era is given by Mr. Binney* 
The area is nearly co-extensive with our regions, Nos. 16 
and 17. 

Arion 2 Bulimus 21 Melampus 11 

Limax 3 Achatina 5 Carychimn 1 

Philomycus 2 Pupa 12 Limnsea 34 

Vitrina 2 Vertigo 4 Physa 19 

Succinea 18 Cylindrella 4 Planorbia 21 

Grlandina 6 VeroniceUa 1 Ancylus 10 

Helix 131 

There are also found in the fresh waters of this district Mela- 
niaddd 380, Faludinidce 58, Cydadidce 44, Unionidce 552. 

18. Ameeican Eegion. 

The mass of American land and fresh-water shells are found 
in the central and southern States, the country drained by the 
Mississippi and its tributaries. The HelicidcB are. not more re- 
markable for size and colour than those of northern Europe j 
the most characteristic forms belong to the sub-genus Polygyra 
(or Tridopsis, Haf.), such as Helix tridenfata, albolahris, Mrsuta, 
and septemvolvis. The truly North American forms all belong 
to three genera, viz. — Helix 43, Succinea 8, Pupa 3 species. 
In the Southern States are also found 5 species of Bulimus, 
3 Cylindrellas, 2 Glandinas, and 5 Helicinse, genera whose 
metropolis is in the Antilles or in tropical America. 

The fresh-water univalves include above 100 species of Mela- 
niadce belonging to the genera Certphasia, Melafusus, Anculotus, 
Melatoma, and Amnicola, 15 Faludince, some keeled, and one 

* In several papers in Proc. Acad. Nat. Sci. Phil. 1857, and subsequent years. 
+ Remarks on the Claasification of N. Am. Helices. Annals of Lyceum of Nat. Hist., 
New York. 1863. 



MEXICAN REGION". 109 

muricated (P. magnifica) ; and species of Valvata, Limncea, Physa 
(15), Planorhis, and Ancylus (5). 

The fresh-water bivalves are also extremely numerous : the 
Unionidce are unequalled for their ponderous solidity, the rich 
tinting of their interiors, and the variety of their external forms.* 
Gnathodon cuneatus, Cyrena floridana, 16 species of Cyclas, and 
Pisidium altile, belong to this region. 

19. Oregon and California. 

The Fauna of the region beyond the Eocky Mountains is 
believed to be almost entirely distinct from that of the United 
States. Avion (foliolatus) and Limax (Columbianus), genera not 
indigenous to eastern America, were found near Puget Sound. 
(Gould). We have no information respecting the land and 
fresh-water shells of Eussian America, but from analogy we 
may expect to find a few there identical with those already 
mentioned as occurring in Siberia. t 

- The shells of Oregon and California are principally known by 
the researches of Nuttall, Couthouy, and Binney. 

Helix 34 Physa 9 Cyrena 2 

. Bulimus ...10 Ancylus 4 Cyclas 1 

Achatina 1 Planorbis ]2 Unio I 

Succinea 4 Melania 2 Alasmodon 1 

Limneea 12 Potamides 2 Anodon 3 

Limncea fragilis, a Canadian species, is said to range westward 
to the Pacific ; and L. jugularis to be common to Michigan, the 
North-west territory, and Oregon. (De Kay.) LimrKsa umbrosa, 
Say ? and Planorhis corjpulentus, Say, are found in the Columbia 
Eiver. 

20. Mexican Eegion. 

The lowlands of the northern half of Tropical America con- 
stitute only one botanical region, extending from the Eio Grande 
del Norte to the Amazon ; but on zoological grounds it may be 
divided into two smaller areas. The Mexican province, including 
Central America, itself comprises three physical regions : the 
comparatively rainless and treeless districts of the west ; the 
?aountains or high table-lands with their peculiar flora ; and 

* The private cabinet of Mr. Jay contains above 200 species of North American 
Unionidce, and very many vaiieties, 

t The affinity between the Mammalia of the Old and New Worlds is greatest in 
eaatem Asia and north-west America, and diminishes vrith distance from those 
regions. ( Waterhotise, in Johnston's Physical Atlas, No. 28.) 



110 MANUAL OP THE MOLLtJSCA. 

the rainy wooded region that borders the Caribbean Sea. The 
land snails of Central America resemble those of the Antilles 
in the prevalence of some characteristic genera — Olandina, 
Cylindrella and Helicina, — of which very few species are found 
on the northern Coast of the Gulf of Mexico. The Bulimi are 
numerous, but chiefly thin, translucent species. 

Helix 33 Glandina 25 Cistula 7 

Proserpina 1 Tomatellina 1 CyclophoniiS 3 

Bulimus 50 Pupa 1 Chondropoma 3 

Succinea 6 Cylindrella 20 Megaloma ,, 2 

Achatina(Spiraxis) .. 35 Oyclotus 1 Helicina , 22 

Amongst the fresh- water shells are Neritina pida, Cydaa 
maculata, Oorhicula convexa, and 7 species of Cyrena. From 
Mazatlan, Mr. Carpenter describes Cyrena oUvacea and Mexicana, 
Gnathodon trigonus, Anodon ciconia (allied to the Brazilian 
A. anserina), Physa auraniia and elata, Flanorhis sp. Melampua 
oUvaceus. Two brackish-water species, Oerithidium varicosum 
and Montagnei, are common to South America. 

21. Antilles. 

The West Indian Islands have supplied nearly 500 species of 
HelicidcB, a larger number than any province except the Lusi- 
tanian ; and above 260 Cydostomidce, or nearly three times as 
many as India. They are also richest in generic forms, and 
the climate is highly favourable to the multiplication of indi- 
viduals. The meau temperature of the Antilles is 59^ — 18°, 
and the annual fall of rain exceeds 100 inches in most of the. 
islands. 

Helix 200 Pupa 26 Cyclophorus 1 

Stenopus 2 Cylindrella 73 Cyclotus 14 

Sagda ,.,,. 20 Clausilia , 1 Megalom,a 8 

Proserpina ,.... 5 Balea 1 Helicina 43 

Bulimus 53 Succinea 16 Alcadia 17 

Achatina 27 Chondropoma 15 Troehatella 10 

Glandina ,.••... 46 Choanopoma 63 Lucidella 6 

Spiraxis 9 AdamsieUa 10 Stoastoma 20 

Tomatellina....,, 1 Cistula 36 Geomelania 21 

Probably every island has some peculiar species, and those 
of the great islands like Cuba and Jamaica are nearly all dis- 
tinct. To Jamaica belong the species of Stoastoma, Sagda, and 
Geomelania, the small sub-genus Lucidella, the Alcadias and the 
mass of beautiful Cyclostomas with a decollated spire and 
fringed lip [Choanopoma, AdamsieUa, Jamaica, Chondropomu, 



COLTIMBIAJT EEGIOK'. Ill 

part, and Cisfula, part.)* The solitary Clausilia is found in Porto 
Kico, the Baled in Haiti, and the Tornatellina in Cuba ; Stenopiia 
is peculiar to St. Vincent's. Bermuda has 4 Helices, of which one 
is common to Texas and one to Cuba. The Chondropomas are 
found in Cuba and Haiti. 

The West Indian Achatince belong to the sub-genera Glandina, 
Liguus and Bpiraxis ; the Bulimi are sharp -lipped and mostly 
small and slender [SuhuUna, Orthalicus). Helix (Sagda) epis- 
tylium, H. Carocolla^ and Succinea (Amphibulima) patula are 
characteristic forms. 

Although connected with Plorida by the chain of the Bahamas, 
and with Trinidad by the lesser Antilles, very few species are 
common to the mainland of either North or South America ; 
the relation is generic chiefly. 

The Limacidce are represented by Vaginulus (Sloanei) ; and in 
the fresh waters there are species of Physa (3), Flanorhis (8), 
Ancylus, and the peculiar OundlacMa, Valvata pygmcea, Am- 
pullaria (fasciata), Faludestrina (minute species), Hemisinus, and 
2 species of Pisidium. 

In the brackish waters are Oerithidium, Neritina [e.g. melea- 
gris, pupa, virginea, viridis), Melampus (coniformis), and Fedipea 
quadridena. 



22. Cqlumbiak BEGION.f 

The tract shaded in the map comprehends seyeral minor 
regions; 1, the rainy and wooded states of New Granada and 
Ecuador; 2, the elevated and nearly rainless province of Vene- 
zuela, with a flora like that of the higher regions of the Andes ; 
3, the Guianas, including the Valley of the Amazon, where the 
forests are most luxuriant, and rain falls almost daily (amount- 
ing to 100 or even 200 inches in the year). Most of the low 
lands, like those of the Mexican Province, belong to the ' ' Cactus 
Eegion " of botanists, and have a mean temperature of 68° — 84''. 
Land shells are abundant in the forests and underwood of the 
lower zone of the mountains, where the temperature is 10** 
less and the rains more copious. Bulimi are the predominant 
forms, especially the succinea-shaped species, (e.g. B. succinoides). 

* A magnificent collection of Jamaica land shells has been presented to the British 
Museum by the Hon. E. Chittty, whose researches were conducted with the late 
Professor C. B. Adams. 

t In 1821 the States of New Granada, Venezuela, and Ecuador united to form the 
" Columbian Republic," but dissolved again in 1831. 



112 MANtTAL OF THE MOLLUSCA. 

Helix 49 Pupa 7 Cistula 1 

Streptaxis 3 Clausilia 4 Bourciera 1 

Bulmius 200 Cylindrella 1 Cyclotus 8 

Succinea 9 Vitrina 1 Adamsiella 1 

Tornatellina 1 Limax 1 Helicina 6 

Achatina 10 Choanopoma 2 Trochatella 1 

Grlaaidina 5 Cyclophorus 2 

The presence of several species of tlie old-world genera 
Clausilia and Streptaxis — both wanting in North America — ^be- 
comes a significant fact when taken in connection with the 
affinities of the higher animals of South America and Africa. 
These imply a land- way across the Atlantic (at some very remote 
period), more direct than would be afibrded by the continent 
which is believed to have united the boreal regions at the close 
of the Miocene age.* 

Corbicula cuneata and 3 species of Cyrena are found in the 
Orinoco and smaller rivers ; and the remarkable genus MiiUeria^ 
representing the African ^theria, inhabits the Eio Magdalena. 
A species of Ancylus is recorded from Venezuela. 

Galapagos Islands (No. 35). 

The fauna and flora of these islands are peculiar, but related to 
tropical South America. The only known land-shells are 17 
small and obscure species of Bulimus, of which the most remark- 
able is B. achatinellintis. Some of them are peculiar to par- 
ticular islands, like the birds and reptiles, viz. : — Chatham 
Island 2, Charles Island 3, Jacob Island 2, James Island 1. 
*' The Archipelago is a little world within itself, or rather a 
satellite attached to America, whence it has derived a few stray 
colonists, and has received the general character of its indigenous 
productions." (Darwin's Journal, p. 37Y.) 

23. Brazilian Eegion. 

The *' region of Palms and Melastomas," extending from the 
Amazon to the southern tropic, is one of the richest zoological 
provinces. It includes Bolivia, and the largest portion of Peru, 
all that lies to the east of the Andes. The greater part of the 
region is mountainous and rainy and densely wooded, but inter- 
sected by extensive plains [Llanos'), some grassy and fertile, 

* In Lieut. Maury's physical map of the Atlantic, the contour of this former land is 
partly shown by the 2,000 fathom line, extending beyond the Canaries and Madeira, 
and sending out a promonotory to the Azores. ClausilicB are found in Eocene strata ; 
perhaps even in the coal measures (p. 295). Principal Dawson has recently described 
Pupa from the coal measures of Nova Scotia, which may be the same shell alluded 
to here. 



PEEUYIAlNr JiEGION. 113 

others dry, rocky and rainless, especially in the south; it is 
watered by numerous streams — the affluents of the Amazon and 
Plata. The hydrogranhical areas of these two great rivers have 
been represented on the map, but the southern boundary of the 
Brazilian Province extends beyond the line of watershed to 
the tropic, including the head- waters of the Plata, in which the 
same remarkable fresh-water bivalves are found as in the 
Bolivian streams. (D'Orbigny). The mountains around the 
Lake Titicaca are the highest in the New World, and there 
M. D'Orbigny found several species of Helix up to the elevation 
of 14,000 feet; Bulimus Tujpaici ranges to 9,000 feet. The large 
and typical species of Bulimus belong to this province ; B. ovatics 
and oblongus are found near the coast (p. 291), and B. maximus 
farther inland. The auriculoid Bulimi {Otostomus, and Pachy- 
otis, Beck), those with an angular mouth {Goniostomus, Beck), 
and the pupiform species, with a toothed aperture, (^Odonto- 
stomus), are characteristic of this region, and also some of the 
most elongated forms {Oheliscus). The lamp snails {Anastoma) 
and Megaspira, genera inhabiting France during the Eocene 
period, are now peculiar to Brazil ; Simpulopsis is also peculiar, 
and Streptaxis attains its maximum there. The Cydostomidce are 
few, and the other West Indian forms have almost disappeared. 

Helix...... 47 Glandina 1 Cyclophorus , 2 

Streptaxis •••• H Tornatellina 1 Cyclotus 1 

Anastoma 7 Vitiina 5 Cistula ,.,, 1 

Bulimus 250 Omalonyx....... 1 Helicina 12 

Megaspira 2 Simpulopsis 5 

The land slugs are Peltella paUiolum, Vaginulus solea, and 
1 Limax andicolus. The fresh- waters of the interior are rich in 
bivalves of peculiar genera :* — 

Physa.,.. 1 Ampullaria 2 Unio 4 

Ancylus 1 Corbicula 2 Iridina 1 

Planorbis 4 Pisidium 1 Hyria 1 

Paludestrina 2 Anodon 1 Castalia 2 

Marisa 1 MonocondylEea., ........ 1 Mycetopus 3 

Succinea 27 

24. PERTJYiAisr Eegion. 

The long an4 narrow tract between the Andes and Pacific, 
extending from the equator to 25° S. lat. forms a distinct, 
though comparatively unproductive province, including the coast 
of Ecuador, Peru, and Bolivia. It is warm and almost rainless ; 

* The American Expedition explored forty Brazilian streams, and found only one 
jAmpullaria, one Melania^ and one Planorbis. ((Joi^d.) 



114 MANUAL OE THE MOLLTJSCA. 

the clouds discharge themselves on the east side of the Andes, 
and rain is so rare on the west coast that in some parts it only 
falls two or three times in a century. In Peru, during great 
part of the year, a vapour rises in the morning, called, the 
"garua; " it disappears soon after midday, and is followed by 
heavy dews at night. 

Mr. Cuming collected 46 species of land snails in Peru ; and 
Dr. Pfeiffer enumerates 100, but perhaps half the latter were 
from the eastern side of the Andes, belonging to the Brazilian 
Province. They are mostly Bulimi, and are smaller and less 
richly coloured than those of Bolivia and Brazil ; B. Benickei, 
solutus, and turritus are peculiar forms. Cistula Delatreana is 
the only operculated land snail, and Vaginulus limayamis the 
only slug. 

Helix 12 Pupa 1 Ancylus 1 

Bulimus 79 Balea 1 AmpuUaria 1 

Succinea 5 Cistula 1 Paludestrina 2 

Grlandina 1 Physa 1 Cyrena 3 

Tomatellina 1 Planorbis 3 Anodon 1 

25. Argentine Eegion. 

The " region of arborescent Compositse" has afforded scarcely 
any land snails ; only 7 species of Bulimus, and 3 Helices are 
recorded, but some others may have been included with those 
of Brazil and Ghili. From Bolivia this province is separated 
by the wide plains of the Great Desert, or northern prolonga- 
tion of the Pampas ; and all the eastern part has been submerged 
at a recent (geological) period; so that the only promising 
districts are Paraguay and the eastern declivities of the Chilian 
Andes. The fresh-water shells of the La Plata and its tribu- 
taries are more remarkable. 

Chilinia..... 7 Cyclas X Byssoanodon 1 

Planorbis 11 Pisidium X Monocondylsea 6 

Ancylus 4 Corbicula ..,,. 2 Mycetopus X 

AmpuUaria 7 Unio 7 Castalia X 

Asolene 1 Anodon 10 Iridina 1 

Paludestrina 7 

AmpuUaria (Marisa) cornu-arietis is a characteristic shell; 
Paludestrina lapidum has a claw-like (non-spiral) operculum, 
and appears to belong to the Melaniadce. 

26. Chilian Eegion. 

The northern part of Chili belongs to the same physical region 
with Peru, consisting of dry and rainless plains. Here the land 



PATAGOlSriAN EEGION. 115 

"Snails are few and small, and only seen after the dews. At 
Valparaiso rain is abundant during the three winter months, 
and the southern coasts are luxuriantly wooded, and extremely 
wet. The characteristic pulmonifera are the fresh-water 
Chilinias. The genus Buchanania is doubtful. There are 
31 species of Bulimus (including B. Chilensis, Plectostylus) and 
22 of Helix; Succinea Chiloensis, A.ncylus Oayanus (Yalparaiso), 
Planorbis fuscus, Paludestrina sp. Unio Chilensis, Fisidium 
Chilense (Yaldivia). Helix Binneyana is found on the island of 
Chiloe. 

The Island of Juan Fernandez (36) has at least 20 species of 
land shells, all peculiar to it : — 

Helix quadrata. Omalonyx Gaj'ana. Tomatellina mirnita. 

arctispira. Achatina diaphana. „ trochiformis. 

pusio, „ splendida. Succinea Cumingi. 

tessellata. „ buliiQoides. „ mamillata. 

ceroides. „ conifera. „ fragilia, 

marmorella. „ acuminata ? Pannacella Cumingi. 

helicophantoides. Spiraxis consimilis. 

In the adjoining island, Masafuera, are found — 

Tomatellina Recluzii. Succinea semiglobosa. 

Succinea rubicunda. „ pinguis. 



27. Patagoniait Eegion. 

The Pampas, or great plains of Patagonia, are dry and rain- 
less nearly all the year; the vegetation which springs up 
during the light summer rains becomes converted into natural 
hay for the support of the wild animals. In Fuegia the mean 
temperature is 33° — 50°, and there is rain and snow through- 
out the year ; yet the bases of the mountains are clothed with 
forests of evergreen beech.* Bulimus sporadicus is found on the 
banks of the Eiver Negro, and B. lutescens at the Straits of 
Magellan ; Helix lyrata (costellata, D'Orbigny ?) and H. saxa- 
tilis inhabit Fuegia. Succinea magellanica is also found at the 
8traits, and Chilinia fluminea, Limncea viatrix, a Faludestrina, 
Anodon jpuelclianus, and TJnio Fatagonicus in the Eiver Negro. 
Feronia marginata and Fotamides ccelatus were discovered in 
Fuegia by Mr. Couthouy. 

The Falkland Islands are 300 miles east of Patagonia, and the 
only recorded shells are two species of Faludestrina. There is 

* Humming-birds are seen fluttering about delicate flowers, and parrots feeding 
amidst the ever-green woods. (Darwin, p. 251.) 



116 MANTTAL OF THE MOLLUSCA. 

zoological eyidence that these islands were united to the main- 
land of South America at no very distant geological period. 
The flora consists of characteristic plants of Fuegia and Pata- 
gonia, mingled, and overspreading the whole surface; few 
epecies are peculiar. . (J. D. Hooker.)* 



* Dr. Hooker has suggested that not only the Falkland Islands, but the far distant 
Tristan d'Acunha (p. 97) and Kerguelen's-land (p. 99), may be mountain-tops of a 
45ontinent which has been submerged since the epoch of their existing flora. " There 
are five detached groups of islands between Fuegia and Kerguelen's-land (a region 
extending 5,000 miles), all partaking of the botanical peculiarities of the southern 
extremity of the S. American continent. Some of these detached spots are much 
closer to the African and Australian continents, whose vegetation they do not assume, 
than to the American ; and they are situated in latitudes and under circumstances 
eminently unfavourable to the migration of species." 

" The botany of Tristan d'Acunha (which is only 1,000 miles distant from the Cape of 
€rood Hope, but 3,-000 from the Straits of Magellan) is far more intimately allied to that 
of Fuegia than Africa. Of twenty-eight flowering plants, seven are natives of Fuegia, 
or typical of S. American botany. 

" The flora of Kerguelen's-land is similar to, and many of the species identical with, 
those of the American continent. (Its geological structure) would bespeak an antiquity 
for the flora of this isolated speck on the surface of oiu- globe far beyond our power of 
calculation. We may regard it as the remains of some far more extended body of 
laiid." (Botany of Antarctic Voyage, i, pt. 2, 1847). 



DISTEIBUTION OF MOLLTTSCA IN TIME. Il7 



CHAPTEE III. 

ON THE DISTRIBITTION OF THE MOLLUSCA IN TIME. 

The historian of modern geology, Sir Charles Lyell, has taught 
us to regard the stratified rocks as so many monuments, record- 
ing the physical condition and living inhabitants of the earth in 
past ages. 

Each formation consists of a similar and more or less complete 
series of limestones, sandstones, clay, coal, and other strata^ 
representing the deep and shallow seas, the fresh- waters, and 
the terrestrial portions of the surface of the globe, at on© par- 
ticular period of time.* 

The organic remains found in the strata exhibit no such 
repetitions, but are changed gradually and regularly, from the 
earliest to the latest formations ; so that the mass of species in 
each period must have been peculiar and distinctive. 

The important theory, that strata may be identified by fossils, 
was taught by William Smith, early in the present century, and is 
thus expressed in his Stratigraphical System : — ' ' Organised fossils 
are to the naturalist as coins to the antiquary ; they are the 
antiquities of the earth ; and very distinctly show its gradual, 
regular formation, with the various changes of inhabitants in 
the watery element." — "They are chiefly submarine, and as 
they vary generally from the present inhabitants of the sea, so at 
separate periods of the earth's formation they vary as much 
from each other ; insomuch that each layer of these fossil 
organised bodies must be considered as a separate creation ; 
or how could the earth be formed, stratum super stratum, and 
each abundantly stored with a different race of animals and 

plants."! 

The " Prodrome" of M. D'Orbigny is a catalogue of the shells 
(and radiate animals) of each formation, from which it appears 
that the mass of the living population of the globe has been 
changed twenty times since the close of the First or Palaeozoic 
Age ; and although the fossils of the older rocks have not been 
generally classified with the same minuteness, yet enough is 

* The coal-measures and chalk of England cannot indeed be called similar, but the 
Cretaceous formations of the whole world afford mineral types, corresponding to, per- 
haps, every variety of Carboniferous rock. 

t Stratigraphical System of Organised Fossils, 4to.,Lond. 1817. 



118 



MANUAL OF THE MOLLTJSCA. 



known to show that at least ten great changes had taken place 
before the Secondary epoch. 

In the following Table, the first column gives the names of 
the Formations or Periods ; the second contains those by which 
the principal strata are known. 

I. QEOLOaiOAL TABLE. 



roitMATIONS OB 

Periods. 



Names of STeata. 



S3 
O 

< 
3h 



< 
O 



/ 1. Tremadocian 

I- \ 

I 2. Snowdonian... 

jj j 3v Wenlock 

( 4. Ludlow 

( 5. Hercynian ... 

IIL ^ 6. Eifelian 

( 7. Clymenian ... 

■r-r;- f 8. Bernician 

• I 9. Demetian 

V, 10. Permian 

yj j 11. Conchylian ... 

( 12. Saliferous 

/l3. Liassic 

I 14 .Toarcian 

VIL -< 15. Bajocian 

1 16. Bathonian ... 

17. Oxfordian 

VIIL -I 18. CoraUian 

19. Kimmeridgian 

20. PortlancUan... 

(21, Wealden 

IX ^ 

122. Neocomian .. 

'23. Albian 

24. Cenomanian 
X. -^25. Hippuritic ... 

26. Senonian 

(27. Londinian 

^^' ]28. Nummulitic... 

Xn. 29. Falunian 

XIIL 30. Icenian 



( Longinyn d slate . ( Bangor, Wicklow. ) 

^ Lingula flags = Primordial group. (Barrande.) 

( Tremadoc slate. Potsdam sandstone. 

f Llandeilo flags 1 Bala or Coniston 

\ Caradoc sandstone J group. 

J May-hill sandstone = Clinton gi'oup. 

( WooUiope and Dudley limestones. 
L. Ludlow, Aymestry lime., U. Ludlow. 
Spirifer sandstone ; Khine. ) Devonian and 
PljTnouth limestone. > Old Eed 

Petherwin limestone. ) Sandstone. 

Carboniferous limestone (shale and coal. ) 
Coal-measures. (Millstone-grit, coal, &c.) 
Magnesian lime = Zechstein. (Perm.) 



f New Eed sandstone = Bunter. 

\ (Muschel-kalk = Ceratite limestone). 
Red marls = Keuper. Lias bone-bed. 
L. Liaa = Sinemurien and Liasien, 
Marlstone, Alum-shale. (Thouars.) 
Inf. Oolite, FuUer's-earth. (Bayeus.) 

f Great Oolite. (Stonesfield slate ; G. Ool. 

I Bradford cl. Forest m. Com brash.) 

r Kclloway rock = Callovien, D'Orb. 

\ Oxford clay. (White Jura.) 
Coral-rag and Calcareous grit. 
Kimmeridge clay. (Dorsetshire.) 
Portland stone and Purbeck beds. 
Hastings sand and Weald clay. 

f Speeton clay ? (Neuchatel). 

( Lower Green-sand, and Apfien, D'Orb. 
Gault. (District of the Aube, or Albe.) 
Upper Green-sand. (Mans, Cenomanum.) 
Chalk-marl and L. Chalk = Turonien. 

( Chalk with fUnts = BacuUte limestone. 

( Maestricht chalk = Dcmien, D'Orb. 



Thanet sands. Plastic clay, London clay, 
j Bracklesham ; Barton ; 1. Wight ; = Parisie)i. 
\ Hempstead ; Fontainblean ; = Tongrien. 

Faluns of Touraine ; Bordeaux, Vienna. 

Crag of E. Co. = Sub-apennin, D'Orb. 



It must be observed that the number and magnitude of the 
*' Formations " was determined by accident in the first instance, 
and afterwards modified to suit the requirements of theory, and 
to make them more nearly equal in value.* 

* The names of formations are in great measiu-e provisional, and open to criticism. 
Some of them were given by Brongniart and 0. D'Halloy ; others have been more 



DISTRIBrTION OF MOLLUSCA IN TIME. 119 

According to MM. Agassiz and D'Orbigny, all, or nearly all 
the fossils of each formation are peculiar; very few species 
heing supposed to have survived from one period to another. 
Sudden and entire changes of this kind only take place when 
the nature of the deposit is completely altered — as when sands 
or clays rest upon chalk — and in these instances there is usually 
evidence (in the form of beds of shingle, or a change of dip) that 
an interval must have elapsed between the completion of the 
lower stratum and the commencement of the upper. 

Professor Eamsay* has discussed this subject at considerable 
length. He endeavours to prove that where we have a com- 
plete succession of rocks the species die out and appear 
gradually and almost imperceptiby ; that where there is any 
sudden change in the fauna, it is always accompanied by an 
unconformity in the rocks — that is, the rocks do not lie evenly 
on one another, but the lower one shows an eroded surface, or 
its stratifications are not parallel with those of the upper rock. 
A break in the current of animal life is believed to be always 
accompanied by a break in the succession of rocks. Each break 
marks a lapse of time during which no deposition of mud, &c., 
took place on the area marked by the break. As it is assumed 
that the change of specific forms has proceeded at a uniform 
rate throughout geological time, it is argued that the greater the 
difference in the fauna, the longer was the time indicated by the 
break. ' ' I cannot resist the general inference that in cases of 
superposition, in proportion as the species are more or less con- 
tinuous — that is to say, as the break of life is partial or complete, 
first in the species, but more importantly in the loss of old and 
the appearance of new allied or unallied genera — so was the 
interval of time shorter or longer that elapsed between the close 
of the lower and the commencement of the upper formation ; 
and so it often happens that strata a few yards in thickness, or, 

recently applied by D'Orbigny, Sedgwick, Murchison, and Barrande ; and sonae are 
adopted from popular usage. Geographical names, and those derived from charac- 
teristic fossils have been found the best, but no complete scheme of zoological nomen- 
clature has been framed. 

The epithet "Turonien" (25) is rejected, because it conveys the same meaning 
with "Falunian" (29), or Middle Tertiary, the tj^ie of which was taken from 
Touraine. 

The term Icenian is proposed for the PUocene strata because their order of succes- 
sion was first determined by Mr. Charlesworth, in the eastern counties ot England, the 
coimtry of the Iceni. We have left the table as it stood in the first edition of this 
work ; but we should mention here that one formation should be placed at the head, 
viz., the Laurentian, and the beds deposited during and since the glacial epoch at the 
foot. 

* Anniversarj' Addresses, Q. J. Geol. Soc, vols. xix. and xx. 1863 and 1864, 



120 MANTJAL OP THE MOLLUSCA. 

more notably still, the absence of these strata, may serve to 
indicate a period of time as great as the vast accumulations of the 
whole Silurian series." The lapse of time is in most cases further 
marked by extensive denudations of strata. Dui-ing the Palaeo- 
zoic age ten physical breaks are known, six of which occur 
before we reach the Devonian formation. In every case but 
one (and in that the rocks are almost entirely devoid of animal 
remains), there is an entire change in the species and a consider- 
able change in the genera. The breaks in the Secondary period 
are less marked and less numerous, amounting to about four ; 
and they are still less marked in the Tertiary period. 

"We have seen that distinct faunas may be separated by narrow 
barriers in existing seas ; and differences almost as great may 
occur on the same coast-line without the interposition of any 
barrier, merely in passing from a sea-bed of rock and weed to 
one of sand or mud, or to a zone of different depth. It would 
be unreasonable to expect the same fossils in a limestone as in a 
sandstone ; and even in comparing similar strata we must con- 
sider the probability of their having been formed at different 
depths, or in distinct zoological provinces. 

The most careful observations hitherto made, under the most 
favourable circumstances, tend to show that all sudden altera- 
tions have been local, and that the law of change over the whole 
globe and through all time has been gradual and uniform. 
The hypothesis of Sir C. Lyell, that species have been created, 
and have died out, one hy one, agrees far better with facts, than 
the doctrine of periodic and general extinctions and creations. 

As regards the zoological value of the " formations," we shall 
be within the truth if we assume that those already established 
correspond in importance with geographical provinces ; for at 
least half the species are peculiar, the remainder being common 
to the previous or succeeding strata. This will give to each 
Geological period a length equal to three times the average 
duration of the species of marine shells.* 

The Distribution of the Species in the Strata (or in Time) is like 
their distribution in space. Each is most abundant in one 
horizon, and becomes gradually less frequent in the beds above 



* The exact value of these periods cannot be ascertained, but some notion of their 
length may be olttained by considering that the deposits in the valley of the Mississippi^ 
estimated to represent 100,000 years, have been accumulated since the era of many 
existing shells. The same may be said of the elevation of Mont Blanc, the formation 
of the Mediterranean Sea, and other grand physical ' vents. The great cities of anti- 
quity— Eome, Corinth, and Egyptian Thebes— stand upon raised sea-beds, or alluvial 
dep s' ts, containing recent shells. 



DISTRIBUTION" OF MOLLTJSCA IK TllTE. 121 

and below ; the locality of the newest rock in whicL. it occurs 
being often far removed from that of the oldest.* 

That species should be created at a single spot, and gradually 
multiply and diffuse themselves, is sufficiently intelligible. That, 
after attaining a certain climax of development, they should 
decline and disappear, is a fact involved in mystery. But even 
if it depends on physical causes, and is not a law of all Being, its 
operation is equally certain, and does not appear to vary beyond 
moderate limits. 

The deep-sea shells (such as Rliynchonella, Terehratula, and 
Yoldia) enjoy a longer range in time, as well as in space, than 
the littoral species ; whilst the land and fresh- water shells are 
most remarkable for specific longevity, f 

In each stratum there are some fossils which characterise 
small subdivisions of rock, just as there are living species of 
very limited range. 

When species once die out they never reappear ; one evidence 
of their having become extinct consisting in their replacement 
by other species, which fulfilled their functions, and are found 
in deposits formed under similar conditions. (Forbes.) 

The total number of species is greater in the newest forma- 
tions than in those of older date ; but the ratio of increase has 
not been ascertained.! 

Distribution of Genera in Time. — The doctrine of the Identi- 
fication of strata by fossils derives its chief value from the fact 
that the development and distribution of genera is as much sub- 
ject to law as the distribution of species; and, so far as we know, 
follows a similar law. 

Groups of strata, like the zoological provinces, inay be of 
various magnitudes ; and whilst the smaller divisions are cha- 
racterised by peculiar species, the larger groups have distinc"^ 
sub-genera, genera, and families, according to their size and 
importance. 

"William Smith himself observed that ' ' three principal families 
of organised fossils occupy nearly three equal parts of Britain." 

* M. Agassiz and Professor E. Forbes have represented, diagrammatically, the 
distribution of genera in time, by making the horizontal lines (such as in p. 124) swell 
out in proportion to the development of the genera. Those whose commencement, 
climax, and end are ascertained may be represented by a line of this kind — ^Tnii» 
Genera which attain their maxima in the present seas are thus expressed ••OSg 

t Land and fresh-water shells of existing species are found with the fossil bones of 
the Mastodon and Megalonyx, in N. America. (Lyell.) 

% The number in each formation depends on the extent to which it has been investi- 
gated, and on the opinions entertained as to the strata referable to it. Professor 
PhiUips has discussed this subject in his work on Devonian fossils (p. 165), and in the 
" Guide to Geology." 

G 



122 MANUAL Ojt the molltjsca. 

" Echini are most common in the superior strata; 
^^ Ammonites to those beneath ; 
" Producti, with numerous Encrini, to £he lowest." 
This kind of generalisation has justly been considered by Pro- 
fessor E. Forbes of higher importance than the identification of 
strata by species — a method only applicable to moderate areas, 
and becoming less available with distance. Indeed it might be 
assumed that strata geographically distant, yet containing some 
identical species, must difier in age by the time required for the 
migration of those species from one locality to the other. 

A table of the characteristic species of the English strata is of 
little use in America or India, except to show how few and 
doubtful are the identical fossils. Whereas the characteristic 
genera and order of succession of the larger groups are the 
same at the most distant localities ; and whatever value there 
may be in the assumption that particular systems of rocks con- 
tain most workable coal, lead, or rock-salt, is not lessened by 
the circumstance that the species of fossils in those rocks are 
not everywhere the same, since the genera alone are suflB.cient 
to identify them. 

Genera, like species, have a commencement, a climax, and a 
period of decline ; the smallest usually range through several 
formations, and many of the typical genera equal the families 
in duration. 

Groups of formations are called Systems, and these again are 
combined in three principal series : — Palseozoic, Secondary, and 
Tertiary. 

Thirteen geological systems, each having a number of peculiar 
genera, are shown in the accompanying table. (No. II.) Some 
of the genera cited have a wider range, like Belemnites, but are 
mentioned because of their abundance in one particular system. 
The names in italics are existing genera.* 

The third table contains the names of some of the larger 
genera, arranged according to the order of their appearance. 
This diagram conveys the impression that the series of fossili- 
ferous strata is not completely known ; or that the beginning of 
many groups of fossils has been obliterated in the universal 
metamorphism of the oldest stratified rocks. f 

* The Miocene strata contain no extinct genera, and represent only the commence- 
ment of the present order of things. All the deposits now taking place will not consti- 
tute fc.n additional " Formation," much less a " Quaternary System." 

t It was on this account that Professor Sedgwick proposed the term " Palaeozoic," 
rather than " Protozoic," for the oldest fossiliferous rocks. 



TABLE OP CHAEACTEEISTIC GENERA. 



123 



II. TABLE OF CHAEACTEEISTIC GENEEA. 



Systems. 


Genera and Sub- genera. 


1. C AMEBIAN, or 
Lower Silurian 

2. Silurian 

3. Devonian 

4. Cabboniferous... 

5. Permian 


/ Camaroceras, Endoceras, Gonioceras, Pterotheca. 
J Maclurea, Kaphistoma, Holopea, Platyceras. 
j Orthisina, Platystrophia, Porambonites, Pseudo- crania. 
(^Ambonycliia, Modiolopsis, Lyrodesma. 

1 Actinoceras, Phr^^gmoceras, Trochoceras, Ascoceras. 
' Theca, Holopella, Murchisonia, Atrypa, Retzia. 
( Cardiola, Clidophorus, Goniophorus, Grammysia. 

[ Bactrites, Gyroceras, Clymenia, Apioceras, Serpularia. 
< Sprrifera, Uncites, Merista, Davidsonia, Calceola. 
( Stringocephalus, Megalodou, Orthonota, Pterinea. 

I Nautiloceras, Discites, Goniatites, Porcellia. 

J Naticopsis, Platyschisma, Metoptoma, Productus. 

( Aviculo-pecten, Anthracosia, Conocardium, Sedgwickia. 

3 Camarophoria, Aulosteges, Strophalosia. 
(Myalina, Bakewellia, Axinus, Edmondia. 


6. Tkias 

7. L. Jurassic 

8. U. Jurassic 

9. L. Cretaceous ... 
10. U. Cretaceous ... 


f Ceratites, Naticella, Platystoma, Koninckia, Cyrtia. 
\ Monotis, Myophoria, Pleurophorus, Opis. 

/'Belemnites, Beloteuthis, Geoteuthis, Ammonites. 
J Alaria, Trochotonui, Eimula, Pileolus, Cylindrites. 
J Waldheimia, Tkecldium, Spiiiferina, Ceromya. 
(_Gryphsea, Hippopodium, Cardinia, Mycconcha. 

/" Coccoteuthis, Leptoteuthis, Nautilus. 
1 Spinigera, Purpurina, Nerinsea, Neritoma. 
J Pteroperna, Trichites, Hypotrema, Diceras. 
(_ Trigonia, Pachyrisma, Sowerbia, Tancredia. 

i Crioceras, Toxoceras, Hamulina, Baculina. 
l Requienia, Caprinella, Sphsera, Thetis. 

/Belemnitella, Conoteuthis, Turrilites, Ptychoceras. 
J Hamites, Scaphites, Pterodonta, Cinulia, Tylostoma. 
J Acteonella, Globiconcha, Trigonosemus, Magas, Lyra. 
(^Neithea, Inoceramus, Hippurites, Caprina, Caprotina. 


11. Eocene 

1 

12. Miocene 


/Belopiera, Lychnus, Megaspira, Glandina, Typhis. 
) Volutilithes, Clavella, Pseudoliva, Seraphs, Bimella, 
"S Conorbis, Strepsidura, Globulus, Phxyrus, Velates. 
(Chilostoma, Volvaria, Lithocardium, Teredina. 

i Spirulirostra, Aturia, Vaginella, Ferussina. 

J Halia, Proto, Deshayesia, Niso, Cassidaria, Carolia. 

( Grateloupia, Artemis, Tapes, Jouannetia. 

f Argonauta, Strombus, Purpura, Trophon. 
\ ioldia, Tridacna, Circe, Verticordia, 


13 Pliocene 





G 2 



124 



MANUAX OF THE MOILTJSCA. 



III. EANGE OF GENEEA IN TIME. 



1 

Genera, arranged in tlieir 
Order of Appearance. 


Cambrian. 

Silurian. 

Devonian. 

Carbonif. 

Permian. 


Trias. 
L. Jura. 
U. Jura. 
L. Cret. 
U. Cret. 


Eocene. 

Miocene. 

Pliocene. 


Lituites, Eaphistoma, Obelus 







— 


Camaroceras, Atrypa, Pterinea 

Gomphoceras, Beilerophon, Pentamerus 
Orthis, Conularia, Murcliisonia 


Spirifera, Athyris, Posidonomya 

Isoarca 







Conocardium, Megalodon, ciionetes '. 

Cardiomorplia 


Ortkoceras, Loxonema, Cyrtia 

Pleurotomaria, Porcellia 


Productus, Macrochilus, Streptorhynclius 

Goniatites, Pleurophorus 

Edmondia, Myalina 





— 


Acteonina 


Terebratula, Pinna, Cyprina ..' . 


Lima 




.^^ 





Gei-villia, Myoconcha 


Ammo7ufes, Naticella, Opis 

Trigonia, Isocardia, Thecidium 

Cerithium, Plicatula, Cardita 

Trochotoma, Tancredia, Giyphaea 











Ancyloceras, Inoceramus, Unicardium . . . 

A starte, Pholadomya, Corbis 

Nerinsea, Goniomj'a, Exogja-a 








Terebratella, Limopsis, Neaera, Argiope ... 

Baculitea, Cinulia, Eadiolites 

Physa, Paludina, Unio, Cyi-ena ... 


Aporrliais, Tornatella, Pyrula 


Pectunculus, Thetis, Crassatella 

Crenella, Chama 


Voluta, Conus, Mitra, Haliotis, &.c 


Helix, Auricula , Cyclostoma 


Pseudoliva, Eostellaria, Seraphs 

Purpura, Strombus 


Argonauta, Tridacna 









The genera of tlie older rocks are believed to be nearly all 
extinct ; for altbougb tbe names of many recent forms appear 
in the catalogues of Palaeozoic fossils, it must be understood 
that they are only employed in default of more exact infor- 
mation. Buccinum, Melania, and Mya have been long since 
expunged ; and Modiola, Nucula, and Natica, are only retained 
until the characters which distinguish them are better under- 
stood. 



RANGE OF FAMILIES IN TIME. 



125 



lY. EANGE OF FAMILIES IN TIME. 



Systems ) 
of Strata, j 


Cambrian. 

Silurian. 

Devonian. 

Carbonif. 

Permian. 


Trias. 
L. Jura. 
U. Jura. 
i;. Cret. 
U. Cret. 


Eocene. 
Miocene. 
Pliocene. 
Eecent. 




Argonautidse 

Teuthidee— Sepiadee 




























Atlantidffi — Hyaleidae 

Strombidee — ^Buccinidee 

ConidcB— Volutidae 

Naticidee— Calyptrseidse 

PjTamidellidBe 






— 































Fissurellidee— TornatellidEe 

Neritidge— Patellidse 


































"RnlliVltP 










HelicidEe — ^LimacidEe 

Limnaeidee — ^Melaniadae 

Auriculidse — Cyclostomidee 









— 







Terebratulidse 




















CraniadEe — Lingulidse 






























Arcadse — ^Trigoniadee 






















, 


















Cardiadse — Lucinidee 












Cj^rinidae — ^Anatinidae 
















Veneridae — Tellinidse 

IVIactridEe 








— 


- — 








Gastrocheenidee — Pholadids 














_ 



Distrilnition of Families of Shells in Time. — Employing the term 
"families" for natural groups of genera, and adopting the 
smallest possible number of them, we find that sixteen, or 
nearly one-fifth, range through all the geological systems. Only 
seven have become extinct, viz. : — 



Belemnitidse. 
Ammonitidje. 
Ortlioceratidae. 



Spiriferidse. 

Orithidse. 

Productidse. 



Hippuritidse. 



126 MARTIAL OF THE MOLLTJSCA. 

Throe others are nearly extinct ; — 

Nautilidse. Ehynclionelljdae. Trigoniadse. 

And several have passed their maximum, and become less varied 
and abundant than formerly, e.g. — 

Tornatellidae. Cyprinidae. Anatinidae. 

The extinct families and genera appear to have attained thei* 
Tnaxima more rapidly than their minima ; continuing to exist,,. 
under obscure forms, and in remote localities, long after the 
period in which they flourished. 

The introduction of new forms, also, is more rapid than the 
process of extinction. If four Palaeozoic families disappear, 
twenty-six others replace them in the Secondary series; and 
three of the latter are succeeded by jBfteen shell-bearing families 
in the Tertiary and existing seas. 

In consequence of this circumstance, the number of types is 
three times greater in the newer Tertiary than it was at the 
Silurian period; and since there is no evidence or indication 
that the earth was ever destitute of life, either wholly or in 
part, it follows almost as a matter of necessity that the early 
types must have been more widely distributed and individually 
developed, than those of the present day. 

Erom the following Table it will be seen that the number of 
genera and families increases with an amount of regularity 
which cannot be accidental. Moreover, the relation of these 
numbers is not liable to be much altered by the progress of 
discovery or the caprice of opinion. The discovery of new types 
is not likely to be frequent ; the imposition of new names, in 
place of the old, will not increase the number of Palaeozoic 
genera ; and the establishment of fresh and arbitrary distinc- 
tions will affect all the groups in due proportion. 

If the number of groups called " Systems " were reduced to 
seven (viz. , three Palaeozoic, three Secondary, and one Tertiary, 
as shown in the following Table), then the average duration of a 
genus of shells would be equal to a System of Formations. 

The duration of the smallest well-defined Families of shells 
is about equal to one of the three great Geological Divisions, 
or Ages. 



"DISTRIBUTIOIf OF MOLLUSCA IN TIME. 



127 



DEVELOPMENT OF FAMILIES, GENEEA, AND 
SPECIES, IN TIME. 



Geological 

Systems. 



, (Cambrian 

'(Silurian 

2 Devonian 

o J Carboniferous 

(Permian* 

4 Trias 

c jL. Jurassic 

(U. Jurassic 

« j L. Cretaceous 

(U. Cretaceous 

^Eocene 

7-|Miocene 

(Pliocene 

Recent 

Eecent & Fossil 



Total 

of 

Genera. 



49 
53 

77 
79 
66 



81 
107 
108 
123 
148 



172 

178 
192 
400 



520 



56 



85 
97 

loa 

251 



280 



34 



72 

76 

79 

115 



150 



Total 
Number of 

Species 
(D'Orbigny). 



362 

317 

1035 

835 
74 



713 

1502 
1266 

784 
2147 



2636 

2242 

437 

16,000 



30,000 



a 



85 \ 

42 

49 

62 

56 



18 

20 

24 1.32 

30 

30 



57 



60 

78 
85 



Order of Appearance of the Groups of Shells. — The first and most 
important point shown in the preceding Tables, is the co- 
existence of the four principal classes of testacea from the earliest 
period. The highest and the lowest groups were most abundant 
in the palaeozoic age; the ordinary bivalves and univalves 
attain their climax in existing seas. If there be any meaning 
in this order of appearance it is connected with the general 
scheme of creation, and cannot be inquired into separately ; but 
it may be observed that the last- developed groups are also the 
most typical, or characteristic oj their class (p. 49). 

The Cephalopoda exhibit amongst themselves unmistakable 
evidence of order in their appearance and succession. The 
tetrabranchiate group comes earliest, and culminates about the 
period of the first appearance of the more highly-organised cuttle- 
fishes, f The families of each division which are least unlike 

* Those genera are estimated as belonging to each system which occur in the strata 
both above and below, as well aa *Jiose actually found in it. We have left this table as 
it stood in the first edition, as we are unable to correct aU the figures. This, however, 
is not of much inaportance, since the main points, such as the gradual increase in the 
number of families, would not be affected. 

t The Palceoteuthis of Eronn (notD'Orb.) appears to be s, fish-bone, from the equ'va* 
ent of the Old Eed sandstone in the Eifel. 



128 MANUAL OF THE MOLLUSCA. 

{Orthocerafidce and Belemnitidce) were respectively the first de- 
veloped. 

Amongst the BracMopoda the hingeless genera attained their 
maximum in the palaeozoic age, and only three now survive 
{Lingula, Discina, Crania,) — the representatives of as many 
distinct families. Of the genera with articulated valves, those 
provided with spiral arms appeared first and attained theii 
maximum while the Terehratulidce were still few in number. 
The subdivision with calcareous spires disappeared with the 
Liassic period, whereas the genus Ehynchonella still exists. 
Lastly, the typical group, Terehratulidce, attained its maximum 
in the chalk period, and is scarcely yet on the decline. The 
number of sub -genera (as well as genera) in each system is 
stated in the preceding table, because this group shows a ten- 
dency to ''polarity," or excessive development at the ends of 
the series.* 

The genera of ordinary bivalves {Conchifera) are seven times 
more numerous in the newer tertiary than in the oldest geo- 
logical system. The jDalseozoic formations contain numerous 
genera of all the families with an open mantle ; Cyjorinidce, 
Anatinidce, and the anomalous genus Conocardium. The mass 
of siphonated bivalves do not appear till the middle of the 
secondary age, and are only now at their maximum. 

The Gasteropoda a.re represented in the palaeozoic strata by 
several genera closely allied to the dim i n utive A tlanta and Scissu- 
rella, and by others perhaps related to lanthina. The NatiddcB 
and Calyptroiidce are plentiful, and there are several genera of 
elongated spiral shells referred to the Fyramidellidce. In the 
secondary strata, holostomatous shells become plentiful ; and in 
a few peculiar localities (especially Southern India) the genera 
of siphonated univalves make their appearance in strata of 
Cretaceous age. Fresh-water Fulmonifera of the recent genus 
Physa occur in the Purbeck strata, but the marine air-breathers 
and land- snails have not certainly been found in strata older 
than the Eocene tertiary. 

Order of Succession of Groups of Shells. — It has been already 
pointed out that animals which are closely allied in structure 

* See the anniversary address of Professor E. Forbes to the Geological Society of 
London, Feb., 1854, p. 63. The hyi^othesis seems to have arisen out of an exclusive 
regard to the poverty of the Permian and Triassic strata in England, where tliey 
separate, like a desert, the palaeozoic from the " neozoic " formations. The " Permian" 
should never have been esteemed more than a division of the carboniferous 
system, and is poor in species, ratlier than in types. The Trias must be studied in 
Germany, or in the collection of Dr. Klipstein (in the British Museum) to be properly 
appreciated. 



DISTRIBUTION OF THE MOLLtJSCA IN TIME. 129 

and liabit rarely live together, but occupy distinct areas, and 
are termed " representative species." The same thing has been 
observed in the distribution of fossils ; the species of successive 
strata are mostly representative. 

At wider intervals of time and space, the representation is 
only generic, and the relative proportions of the larger groups 
are also changed. 

The succession of forms is often so regular as to mislead a 
superficial observer ; whilst it affords, if properly investigated, 
a valuable clue to the affinities of problematic fossils. 

It is now generally admitted that the earlier forms of life, 
strange as many of them seem to us, were really less meta- 
morphosed—or departed less widely from their ideal archetypes 
— than those of later periods and of the present day.* The 
types fijfst developed are most like the embryonic forms of their 
respective groups, and the progression observed is from these 
general tyj)es to forms more highly specialised. (Owen.) 

Migration of Species and diffusion of Genera in Former Times. — 
Having adopted the doctrine of the continuity of specific and 
generic areas, it remains to be shown that such groups as are 
now widely scattered can have been difi'used from common 
centres, and that the barriers which now divide them have not 
always existed. 

In the first place it will be noticed that the mass of the 
stratified rocks are of marine origin, a circumstance not to be 
wondered at, since the area of the sea is twice as great as the 
land, and probably has always been so ; for the average depth 
of the sea is much greater than the general elevation of the 
land.-f 

The mineral changes in the strata may sometimes be accounted 
for by changes in the depth of the sea, or an altered direction 
of the currents. But in many instances the sea-bed has been 
elevated so as to become dry land, in the interval between the 
formation of two distinct marine strata ; and these alterations 
are believed to occur (at least) once in each formation. 

If every part of what is now dry land has (on the average) 

*• Mr. Darwin has pointed out that the sessile Cirripedes, which are more highly 
metamorphosed than the Lepadidce, were the last to appear. The fossil mammalia 
afford, however, the most remarkable examples of tliis law. At the present day such 
an animal as the three-toed horse {Hif-pothernmi) of the Miocene Tertiary would be 
deemed a lusus natura, but in tnith the ordinary horse is far more wonderful. Un- 
fortunately, a new " vulgar error" has arisen from the terms in which extinct animals 
have sometimes been described, as if they had been constructed upon sei;eral distijict 
types, and combined the character of several classes. 

t The enormous thickness of the older rocks in all parts of the world has been held 
|o indicate the prevalence of deep water in the primecval seas. 

G 3 



130 MANUAL or THE MOLLtJSCA. 

been thirty times submerged, and has formed part of tbe sea- 
bed during two-thirds of all the past geological time, — there 
will be no difficulty in accounting for the migration of sea-shells, 
or the diflFusion of marine genera. 

On the other hand, it may be inferred that every part of the 
present sea has been dry land many different times; on an 
average not less than thirty times, — amounting to one-third 
of the whole interval since the Cambrian epoch. 

The average duration of the marine species has been assumed 
at only one-third the length of a geological period, and this 
harmonises with the fact that so few (either living or extinct) 
have a world-wide distribution. 

The life of the land-snails and of the fresh-water shells has 
been of longer average extent, enabling them to acquire a wide 
range, notwithstanding their tardy migrations. 

But when we compare the estimated rate of change in physical 
geography with the duration oi genera emd. families of shells, we 
not only find ample time for their diffusion by land or sea over 
large portions of the world, but we may perceive that such 
transferences of the scene of creation must have become in- 
evitable. 

Method of Geological Investigation. — ^In whatever way geo- 
logical history is written, its original investigators have only 
one method of proceeding — from the knOwn to the unknown — 
or backwards in the course of time. 

The newest and most superficial deposits contain the remains 
of man and his works, and the animals he has introduced. 

Those of pre-historic date, but still very modern, contain 
shells, &c., of recent species, but in proportions different from 
those which now prevail (pp. 89, 90, 93). Some of the species 
may be extinct in the immediate neighbourhood of the deposits, 
but still living at a distance. 

In the harbour of New Bedford are colonies of dead shells of 
the Pholas costata, a species living on the coast of the Southern 
States. At Bracklesham, Sussex, there is a raised sea-bed 
containing 35 species of sea-shells living on the same coast, 
and 2 no longer living there, yiz. — Pecten polymorphus, a Medi- 
terranean shell ; and J^utraria rugosa^ still found on the coasts 
of Portugal and Mogador. 

Tertiary Age. — If any distinction is to be made between 
" Tertiary" and ** Post- tertiary" strata, the former term should 
be restricted to those deposits which contain some extinct species. 
And the newest of these, in Britain, contain an assemblage of 
Northern shells. Professor Forbes has published a list of 124 



DlSTRIBtJTION OF THE MOLLUSC A IN TIME. 131 

species of shells from these " Glacial beds," nearly all of which 
are now existing in British seas.* 

In most of the localities for glacial shells, the species are all 
recent ; but at Bridlington, Yorkshire, and in the Norwich 
Oay, a few extinct species are found (e.g. Nucula Cobholdice, 
PL 17, f. 18). At Chiliesford, Suffolk, Yoldia arctica and myalis 
occur of large size and in excellent preservation, with numerous 
specimens of Mya truncata, erect as they lived, in the muddy 
sea-bed. Trophon acalariforme, Admete viridula, Scalaria green- 
landica, and Nativa groenlandica, also occur in the Norwich Crag ; 
and Astarte horealis, with several arctic forms of TelUna, are 
amongst the commonest shells, and frequently occur in pairs, 
or with their ligament preserved; the deposit is extensively 
quarried for shell- sand. 

Eaised sea-beds with Arctic shells at TJddevalla, in Sweden, 
have been repeatedly noticed ever since the time of Linnaeus. 
Captain Bayfield discovered similar beds near Quebec, 50 — 200 
feet above the Eiver St. Lawrence, containing an assemblage of 
shells entirely Arctic in character ; whereas in the present gulf 
he obtained an admixture of the American representatives of 
Lusitanian types, Mesodesma, Periploma, Petricola, Crepidula. 

The glacial deposits of the northern hemisphere extend about 
15® south of the line of "northern limit of trees;" but this 
comparatively recent extension of the Arctic ocean does not 
appear to have much influenced, if it ever invaded, the inland 
basin of the Aralo-Caspian, which contains only one species 
common to the White Sea, Cardium edule, var. rusticum.-\ 

The older pliocene period is represented in England by the 
Coralline Crag, a deposit containing 340 species of shells. Of 
these 73 are living British species, but (with two or three ex- 
ceptions) they are such as range south of Britain. (Forbes.) 
The remainder are extinct, or living only to the south, especially 
in the Lusitanian province : e.g. Fossarus sulcatus, Lucinopsis 
Lajonhairii, Chama gryphoides, and species of Cassidaria, Gleo- 
dora, 8igaretus, Terehra, Columhella, and JPyramidella. It also 
contains a few forms belonging to an earlier age — a Fholadomya, 
a true Fyrula, a Lingida, and a large Voluta, resembling the 
Magellanic species. 

* The species which have retired farther north are marked (**) in the preceding 
Arctic List, pp. 57, 58. 

t Mr. Wm. Hopkins, of Cambridge, has investigated the causes which may have 
produced a temporary extension of the Arctic phenomena in Europe ; and considers 
the most efBicient and probable cause would be a diversion of the Grulf-stream, which 
he supposes to have flowed up what is now the valley of the Mississippi. ( Geological 
Journal) . 



132 MANUAI OP THE MOLLTJSCA. 

The shells of the newer tertiaries are always identical, at least 
genericaUy, with those of the nearest coasts. Thus, in Pata- 
gonia are found species of Troplion, Crepidula, Monoceros, 
PseudoUva, Valuta, OJiva, Crassatella, and Solenella. The ter- 
tiaries of the United States contain species of Fulgur, Mercenaria, 
and Gnathodon. The miocene shells of St. Domingo appear at 
first sight to he all of recent species, but on comparison prove 
to be mostly distinct. 

The proportion of extinct species in the Pliocene tertiary 
varies from 1 — 50 per cent. If a deposit contains more than 
50 per cent, of extinct species it is referred to the Miocene 
period ; and this test is particularly valuable since the modern 
deposits are often isolated, and frequently no assistance can be 
derived from superposition, or even from identity of species. 

In the Eocene tertiaries we perceive the "dawn" of the present 
order of things. All, or very nearly all, the species are different, 
but a large proportion of the genera are still existing, though 
not always in the seas nearest to the localities where they occur 
fossil. 

Thus in the London clay are found — Bosfellaria, Oliva, Ancil- 
laria, and Vulsella, genera still living in the Eed Sea ; and many 
species of Nautilus, Bimella, Seraphs, Comes, Mitra, Pyrula, 
Pliorus, Liotia, Cardilia — genera characteristic of the Indian 
Ocean ; Cyprovula, Typhis, and Volutilithes, now living at the 
Cape ; Clavella, at the Marquesas, and PseudoUva, Trochita, and 
species of Murex, whose recent analogues are found on the 
western shores of South America. 

The freshwater shells of this period are Old World forms : 
Melanopsis, Potamides, Lampania, Melanatria, and Nematura ; 
whilst the land- shells form a group quite American in character 
— large species of Glandina and Bulimus (with reflected lip) 
Megalomastoma (jnumia), a Cyclotus (with its operculum) like C, 
Jamaicensis, and the little Helix lahyrinthicus. 

Secondary Age, — In none of the older strata do we find indica- 
tions of a warmer climate having prevailed, in the latitude of 
England, than that which marks the period of the London clay. 
And this is not more than can be accounted for by such a cause 
as the flow of an equatorial current from the direction of the 
Eed Sea, until arrested by a continent to the south-west, as 
supposed by Mr. Prestwich, in the region of the Azores. 

Some indications exist of a more moderate climate having 
obtained in the north polar regions ; for remains of the Ichthyo- 
saurus were found at Exmouth Island, the farthest point reached 
by Sir E. Belcher's expedition. 



DISTE'IBUTION OF THE MOLLTJSCA IN TIME. 133 

The peculiar physical conditions of the Chalk period are 
represented at the present day, not so much by the Ooral Sea, 
as by the JSigean, where calcareous mud, derived from the waste 
of the scaglia regions, is being rapidly deposited in deep water. 
{Forbes.) 

The Wealden period was styled the " Age of Eeptiles " by Dr. 
Mantell, who compared the state of England at that time with 
the present coEdition of the Galapagos Islands. 

The Oolitic period finds its parallel in Australia, as long since 
pointed out by Professor Phillips, and the comparison holds 
good to some extent, both for the Marine and Terrestrial 
Faunas. 

The Trias, with its foot-prints of gigantic wingless birds, has 
been compared with the state of the Mascarene Islands only a 
few centuries ago, and with the New Zealand Fauna, where 
birds are still the highest aboriginal inhabitants.* 

Palceozoic Age. — It has lately been shown by Professor Eamsay 
that signs of glacial action may be traced in some of the trappean 
conglomerates of the Permian and of the Devonian or Old Eed 
Sandstone period in England ; and Mr. Page has endeavoured 
to apply the same interpretation to phenomena of a similar cha- 
racter in the Old Eed sandstone of Scotland, t Geologists gene- 
rally have abandoned the notion, once very prevalent, of a 
universal high temperature in the earliest periods ; a notion 
which they had derived from the occurrence of certain fossil 
plants, corals, and shells in high latitudes. 

The absence of remains of mammalia in the palseozoic forma- 
tions, is at present a remarkable fact, but it is completely 
paralleled in the great modern zoological province of the Pacific 
Islands. 

Baron Humboldt has speculated on the possibility of some land 
being yet discovered, where gigantic lichens and arborescent 
mosses may be the princes of the vegetable kingdom. J If such 
exist, to shadow the Paleeozoic age, its appropriate inhabitants 
would be like the cavern-haunting Proteus, and the Silures 
which find an asylum even in the craters of the Andes. 

What, then, is it which has chiefly determined the character 
of the present zoological provinces ? What law, more powerful 
than climate, more influential than soil, and food, and shelter ; 

* In a paper read before the British Association, on the subject of tlie great extinct 
wingless bii'ds of New Zealand, Professor Owen suggested the notion of land having 
been propagated like a wave tlu-oughout the vast interval between Connecticut and New 
Zealand, since the Triassic period. 

t See also the Rev. J. G. Cumming's " Isle hi Man '' (1849), p. 89. 

X Views of Nature, p. 221. Bohn's ed. 



134 



MANtJAL OF THE MOLLUSCA. 



nay, often seemingly producing results opposed to a priori 
probability, and at variance with the suitableness of con- 
ditions ?* 

Tbe answer is, that each fauna bears, above all things, the 
impress of the age to which it belongs. Each has undergone a 
series of vicissitudes up to the time when its barriers became 
fixed, and after its isolation it has known no further change, 
but decline. 

The number of living and fossil species of each genus of 
moUusca will be stated in the following pages, so far as they can 
be ascertained. With some modifications, these numbers give the 
following totals, by which the relative numerical development 
of the orders and families will be seen. 



Eecent. Fossil. 
CephaIiOPODA. Dibranchiata. 

Ai'gonautidse 4 2 

Octopodidae 63 — 

Teuthidse 104 31 

Belemnitidse — 140 

Sepiadse 30 16 

Spinilidae 3 — 

204 189 
Tetrahranchiata. 

Nautilidae 6) „ 

Orthoceratidse . , , — ) 

Ammonitidse — 1600 

6 2193 
Gasteropoda. Pro.sobranchiata> 

Strombidset 87 393 

Muricidse 993 703 

Buccinidae .,. 1,144 352 

Conidse 856 462 

Volutidse 686 210 

Cypraeidae 227 97 

Naticidse 263 340 

Pyramidellidae 216 394 

Cerithiadse 192 610 

Melaniadee 424 50 

TuiTitellidset 329 290 

Littorinidse 410 220 

Paludinidse 217 HO 

Calyptraeidae 160 101 

Turbinidse 855 906 

Haliotidge 104 136 

FissureUidas 201 76 



Recent. 

Neritidee 428 

Patellidse 368 

Dentaliadse 50 

Chitonidse 250 

8,465 
Pulmonifera. 

Helicidse 4750 

Limacidse 93 

Limneeidse 332 

(Mirine) 193 

(Ditto, shell-less) 36 

6^404 
Operciilated Pulmonifera. 

Cyclostomidae 903 

Aciculidse 28 

931 
Tecti-branchiata. 

Tornatellidae 62 

Bullidee 168 

Aplysiadee 84 

Pleurobrancliidge ...... 28 

Phyllidiadce ..••• 14: 

356 
Nudibranchiata. 

Doridee 160 

Tritoniadae 38 

.SEolidae 101 

Phyllirhoidse 6 

Elysiadse 13 

318 



Fossil 

103 

104 

125 

37 

5,819 

316 

4 

185 

37 



642 

45 
1 

46 

166 

88 

4 

5 

263 



*Burchell, in Darwin's Journal, p. 87. 



\ Including Aporrhats 



X With Scalaria, 



IfUMERICAL ESTIMATE. 



135 



Eecent. Fossil. 
Nuclcohranch lata. 

Firolidae 33 1 

Atlantidse 22 159 



55 

Pteeopoda. 

Hyaleidse 52 

Liraacinidae 19 

Clionidce 14 



Beachiopoda. 

Terebratulidre 67 

Spiriferidge — 

Rhynchonellidse 4 

Orthidae — 

Productidse — 

Craniadae 5 

Discinidse 10 

Lingulidee 16 

102 



160 



95 



95 



340 
380 
422 
328 
146 
37 
90 



1,842 



Recent. FossU. 

CONCHIFEEA. 

Ostreidse 426 1,362 

Aviculidae 94 638 

Mj^ilidffi 217 331 

Arcadse 360 1,142 

Trigoniadse 3 139 

UnionidxB 549 58 

Chamidse 50 62 

Hippuritidee — 103 

Tridacnidse 8 3 

Cardiadge 200 369 

Lucinidse. 178 44fi 

Cycladida 176 144 

Cyprindffi 176 956 

Veneridse 600 329 

MactridjE 147 68 

TeUinidse 560 388 

Solenidae 63 81 

Myacidge 121 334 

Anatinidse 246 400 

GastrochgenidsB 40 35 

Pholadidffi 81 50 

4,295 7,419 



General Summary. 



Recent. Eossil. 

Dibranchiata 204 189 

Tetrabranchiata 6 2,193 

Prosobranchiata 8,465 5,819 

Inoperculated Pulnaonif era 5,404 542 

OperculatedPulmonifera.. 931 46. 

Tectibranchiata 356 263 

Nudibranchiata 318 — 



Eecent. Fossil. 



Nucleobrancliiata 55 

Pteropoda 85 

Bracliiopoda 102 

Conchifera 4,295 



16» 
95 

1842 
7,419 



20,502 18,568 



136 MANUAL OF THE MOLLUSCA. 



CHAPTEE IV. 

ON" COLLECTING SHELLS. 

The circumstances under which, shells are found is a subject 
so intimately connected with the methods of collecting them, as 
to make it undesirable to treat of them separately. 

Naturalists distinguish between the habitats^ or geographical 
localities of species, and the stations or circumstances in which 
they are found : to the latter subject only slight allusion has 
been hitherto made (p. 7). 

Land-shells are most abundant on calcareous soils (p. 29), and 
in warm and moist climates. The British species are collected 
with advantage in autumn, when full-grown, and showing 
themselves freely in the dews of morning and evening. Some 
species, like Bulimus acutus, are found only near the sea; Bulimus 
Lackliamensis ascends beech trees on the Chalk downs and Cots- 
wolds ; Pupa Juniperi and Helix wmbilicata occur chiefly on 
rocks and stone walls. The moss-frequenting ClausiUce may be 
obtained even in mild winter weather at the roots of trees ; the 
small species of Pupa (or Vertigo) are sometimes taken abundantly 
when sweeping wet grass with an insect net ; Acicula fusca lives 
at the roots of grass ; Cionella acicula is found in old bones 
(such as occur in Danish burial-grounds !), and occasionally in 
moving garden-bulbs ; Helix aculeata has been met with on the 
under sides of leaves {e.g. the sycamore), a few feet from the 
earth. 

In tropical countries a large number of the land snails are 
arboreal in their habits. The Yfest Indian palms (such as 
Oreodoxa regia) are the chosen abode of many species of Heli- 
cidse. M. Couthouy found Bulimus auris leporis on the orange 
and myrtle-trees near Eio, and Partulce and Helicince, on the 
Dracaenas and Bananas of the Polynesian Islands ; and the 
sailors of H.M.S. Rattlesnake, in Captain Owen Stanley's 
expedition, became expert in collecting Geotrochi in the trees of 
the Australian islands. 

The great troj)ical Bulimi and Achatince will sometimes lay 
their eggs in captivity.* 

* Such giants require to be collected in a basket, wlule the small land-shells of 
open and rocky countries may be put in a cotton bag, hung on a coat button. 



ON COLLECTING SHELLS. 187 

The following are examples of the eleyations at which land- 
snails have been found, (pp. 289, 294.) 

Helix pomatia, 5,000 feet— Alps. (Jeffreys.) 

„ rupestris, 1,200—5,000 ft. 

„ bui-satella, Gould, 2,000—6,000 ft. Taheiti. 
Bulimus vibex, 7,000 ft. India. (Benson.) i 

„ nivicola and omatus, 14,000 ft. „ 

,. Lamarckianus, 8,000 ft. New Granada. 
Achatina latebricola, 4—7,000 ft. Landour. 
Pupa Halleriana, 1,200—2,500 ft. Alps. 

„ tantilla, 2,000 ft. Taheiti. 
Clausilia Idaea, 5,500 ft. Mt. Ida. 
Vitrina glacialis, Forbes, 8,000 ft. Monte Rosa. 

„ annularis, 2,000— 3,000 ft. Burgos. (M' Andrew.) 

., Teneriffee, 2,000-6,210 ft. Madeira. 
Helicina occidentalis, Guilding, 2,000 ft. St. Vincent's. 
(Limnsea Hookeri, 18,000 ft. Thibet.) 

The land- snails of warm and dry regions remain dormant for 
long periods (p. 14), and require no attention for many months 
after being collected.* 

Freshwater shells are collected with an insect net or * ' landing 
net " of strength suited to the work of raising masses of weed. 
The strongly rooted flags and rushes may be pulled up with a 
boat-hook; and Cyclades, as well as univalves, maybe obtained 
by shaking aquatic plants over the net. For getting up the 
pearl mussels, the most efficient instrument is a tin bowl, per- 
forated like a sieve, and fitted on the end of a staff, or jointed 
rod. (Pickering.) 

In some situations the fresh-water shells are all much eroded 
(p. 33,), or coated with a ferruginous deposit. It may be 
desirable to find out the localities where the specimens are 
in best condition before collecting extensively. The opercula 
should always be preserved with the shells to which they 
belong ; those of the CydostomidcB and MelaniadcB are particu- 
larly interesting. 

The Auriculidce are especially met with in damp places by the 
sea ; in mangrove-swamps, and creeks and river-banks where 
the water becomes brackish. Amphihola and Assiminea are 
found in salt-marshes, Siphonaria and Peronia on the shore, 
between tide-marks. 

Collecting Sea- shells. — The following remarks are from the pen 

* Land and fresh-water snails naay be killed instantaneously with boiling water, if a 
few are done at a time ; and cooled by removal to cold water. Every collector finds 
expedients for removing the animals more or less completely from their shells ; those 
which, Uke Clausilia, retire beyond the reach of a bent pin may be drov\ned in tepid 
water. 



138 MANUAL OF THE MOLLTJSCA. 

of an experienced concliologist, Mr. W. J. Broderip : — " When 
the tide is at the lowest, the collector should wade among the 
rocks and pools near the shore, and search under overhanging 
ledges of rock as far as his arms can reach. An iron rake, 
with long close-set teeth, will be a useful implement on such 
occasions. He should turn over all loose stones and growing 
sea-weeds, taking care to protect his hands with gloves, and his 
feet with shoes and stockings, against the sharp spines of Echini^ 
the back-fins of sting-fishes, and the stings of Medusce. In 
detaching chitons and limpets, which are all to be sought for 
on rocky coasts, the spatula or case-knife will prove a valuable 
assistant. Those who have paid particular attention to pre- 
serving chitons have found it necessary to suffer them to die 
under pressure between two boards. Ormers {Haliotides) may 
be removed from the rocks to which they adhere by throwing a 
little warm water over them, and then giving them a sharp 
push with the foot sideways, when mere violence would be of 
no avail without injuring the shell. EoUed madrepores and loose 
fragments of rock should be turned over; cowries and other 
shell-fish frequently harbour under them. Numbers of shell- 
fish are generally to be found about coral-reefs." In coral regions 
the services of natives should be obtained, as they may render 
much assistance by diving or wading. 

Advantage may be taken of spring -tides, especially at the 
equinoxes, to examine lower tracts of sea-shore than are ordi- 
narily accessible. Many bivalves bury in sand and mud at 
extreme low-water, and may be obtained alive by digging with 
a spade or fork ; others may be found boring in piles and rocks, 
and require the hammer and chisel for their extraction.* 

Mr. Joshua Alder remarks that ' ' in collecting among rocks 
the principal thing is to look close, particularly in crevices and 
under stones. Minute species inhabiting sea-weed are best 
obtained by gathering the weed and immersing it for some time 
in a basin of sea-water, when the little moUusks will generally 
creep out. If the shells only are wanted, the surer and more 
ready way is to plunge the weed into freshwater, when the 
animals immediately fall to the bottom." 

The floating moUusca of the open sea, especially in tropical 
latitudes, are comparatively little known. Good drawings, and 
descriptions made from the life, are most valuable. "Of the 
animal of the Spirula, entire specimens are greatly wanted. If 

* Bivalves may be boiled, and th?ir soft parts removed when the shells gape. Care 
should be taken not to injure the ligament, or hinge, especially in the genera (like the 
jinatinid) provided with an ossicle. 



OW COLLECTING SHELLS. 



139 



captured alive, its movements should be watched m a vessel of 
sea-water, to see whether it has the power of rising and sinking 
at will ; its mode of swimming, and position during these move- 
ments, and when at rest. The chambered shell should be opened 
under water, to ascertain if it contain a gas, the nature of whxh 
should, if possible, be made out. The pearly nautilus requires 
the same observations, which would be attended with more 
precision and facility from its larger size." (Owen.)* 

The towing-net used by Mr. McGillivray ' ' consisted of a bag 
of hunting (used for flags) 2 feet deep, the mouth of which was 
sewn round a wooden hoop 14 inches in diameter ; three pieces 
of cord, If foot long, were secured to the hoop at equal inter- 
vals and had their ends tied together. When in use, the net 
was towed astern, clear of the ship's wake, by a stout cord 
secured to one of the quarter-boats, or held in the hand. The 
scope of the line required was regulated by the speed of the vessel 
at the time, and the amount of strain caused by the partially 
submerged net." f 

Trawling, — Mr. John W. Woodall,of Scarbro', has kindly fur- 




Fig. 32. A Trawl-net. A. Side view ; B. Net in op ration ; C. Plan. 

nishedthe following sketches and particulars : — " B, Fig. 32, ia 
intended to represent a trawl-net at work on the bottom of the sea. 

* Admiralty Manual of Scientific Inquiry. 8vo. Lend. 1849. 
t Voyage of H.M.S. Rattlesnake, vol i. p. 27. 



140 MANUAL OF THTE MOLLITSCA. 

The side frames are of iron, the upper beam of wood, and the lower 
edge of the net is kept down to the ground by means of a chain, 
which is wolded or wrapped round with old rope. The beam is 
generally from 40 to 50 feet in length, and about 8 inches square. 
The net is about 30 yards in depth, and has a couple of pockets 
inside. The end is untied when the net is hauled on board for 
the purpose of taking the fish out. These nets can only be 
worked where the bottom of the sea is free from rocks. They 
are used by boats of 35 to 60 tons, manned by crews of from four 
to six men and two to three or four boys. In the vicinity of 
Scarbro' they fish between the shore-reefs and the off rock, which 
is 4 to 10 miles from land ; the bottom is sand or clay, with 4 to 15 
fathom water on the land side, and 17 to 25 fathoms on the off 
side." Immense quantities of Crustacea and shell-fish are taken 
with the trawl, as well as ground-fish. 

Kettle-nets. — On the flat, sandy coast of Kent and Sussex, the 
mackerel-fishery is pursued by setting up stakes 10 or 15 feet 
high, at distances of 10 feet apart, in lines running outwards 
from the shore at high- water, to low-water neap tides, where 
they are turned in the direction of the tide. To these 
stakes nets are attached, and leaded, which remain as long as 
the fish are on the coast. Cuttle-fish are frequently taken in 
these nets. 

Deep-sea Fishery. — In North Britain an extensive ground- 
fishery is conducted by means of long lines — often a mile in 
length — with hooks and baits every few yards. These lines 
are laid out at night near the coast, and taken up the next 
morning. When used out at sea, the boats lay by for a few 
hours, and then take up the lines. The carnivorous whelks 
adhere to the baits (which have not been seized by fishes), and 
sometimes a bushel of them are taken in this way from a single 
line. Rhynchonella psittacea, FanopcBa Norvegica, Velutines, and 
some of the scarce Fusi, have been obtained from these lines, 
the bivalves having been entangled accidentally by the hooks. 

For trapping whelks on rocky ground a net may be made such 
as is used for crabs and lobsters, by attaching a loose bag to an 
iron ring of a yard across. This is fastened to a rope by three 
equal strings, baited with dead fish, and let down from a vessel 
at anchor, or, still better, from a buoy. It is put down over- 
night, and hauled up gently in the morning. 

Mr. D'Urban informs us that Natica Alderi and monilifera 
are frequently found in the lobster-pots at Bognor, Sussex, 
which they enter to feed upon the bait. 

Dredging, — The dredges used in the oyster and whelk- 



ON COLLECTING SHELLS. 



141 



fisheries are so rudely made as to injure the more delicate 
marine animals, and suffer all the minute thinp;s to escape. It 
is therefore necessary to haye instruments specially adapted for 
the naturalist's work. 




Fig. 33. Plan of the Framework of a Dredge, reduced to f. 

Fig. 33 is a plan, and Fig. 34 a side- 
view, of a small dredge, belonging to Mr. 
J. S. Bowerbank, and suited for such 
work as a private collector might do on 
the English coast. It is made of wrought 
iron, with movable joints, so as to fold 
up and carry in the hand. The bag attached 
to the dredge is formed of two pieces of 
raw hide {h, h), connected at the ends 
and bottom by net {n) made of cod-line, 
to allow the water to escape; and is 
fastened to the frame with copper wire, 
through the eyelet-holes. The towing- 
rope is attached to the rings (r, r), and 
when thrown overboard it scrapes with 
one or other of the cutting edges (e, e). 
The opening is made narrow, to prevent 
the admission of large and heavy stones. 

Dredging should not be attempted in a 
rowing -hoat, unless near the shore, in 
smooth water, and with a depth not ex- 
ceeding 5 or 10 fathoms. It may be 
managed in a light boat by two persons ; 
one rowing, the other holding the rope of 
the dredge which is passed overboard near 
the stern. 

The whelk and oyster-dredgers employ 
a decked sailing-vessel, and work several 
dredges simultaneously, each requiring a person to manage it. 




Fig. 34. 



142 MANUAL OF THE MOLLTJSCA. 

The dredges are put overboard on the weather-side, and the 
ropes made fast to a bulwark or thwart; each dredger holds 
the rope in his hand, after giving it a single turn round a thwart 
or "belaying pin," to regulate the strain by means of the 
spare line. When a sufficient distance has been traversed, or 
the ropes strain with the weight of mud and stones, the vessel 
is brought to, and the dredges hauled up and emptied.* 

The length of line required is about double the depth of the 
water. If the line is too short, the dredge will only skim the 
bottom ; if too long, it will be in danger of getting fast. When 
the bottom is loose sand or soft mud, the line must be short- 
ened, or the vessel have more way, or else the dredge will be 
apt to get buried. 

The strength of the line ought to be sufficient to anchor the 
vessel in smooth water, — though not, of course, when there is 
much way on her, — so that if the dredge gets foul it is necessary 
to let out the spare line and relieve the strain while the vessel 
is brought round. The dredge will then usually capsize, and 
may be hauled up. 

If the bottom is at all rocky, a small strong dredge is best. 
The line must be shortened, and some additional precautions 
may be taken, such as fastening the rope to one ring of the 
dredge, and tying the other with spun yarn, which will break 
under a sudden and dangerous strain, and release one end of 
the dredge. 

In dredging on coral-ground, Mr. Cuming employed a 3-inch 
hawser, and had a patent buoy attached to the dredge by a 
Ij-inch rope. More than once the hawser parted, and the dredge 
was left down all night, but recovered the next day. 

Mr. McAndrew's researches on the coast of Norway were 
conducted in the Naiad, a yacht of 70 tons, and extended from 
the shore to 250 fathom water. The dredge employed was at 
least twice as strong and heavy as the one we have represented, 
and all forged in one piece, instead of folding up. The bag was 
fastened on the frame with thongs cut from the hide. Before 
using, it requires to be towed astern for a couple of hours, to 
soften it. In three months' work only two cow-hides were used, 
and one of those was torn by accident on sharp rocks. Several 
spare dredges were on board, in case of emergency, but not used. 

Dredging in deep water (50 to 300 fathoms) can only be done 

* The collector may go out with the fishermen and superintend his own dredge 
almost any time of the year, although oyster catching is illegal in the summer. The 
scallop-banks off Brighton are in 15 fms. water, and nearly out of sight of land. It is 
not always possible to work over them and return the same night. 



ON COLLECirNG SHELLS. 143 

in calm weather, with a light breeze. The yacht is brought to 
the wind (by putting up the helm), the foresheet hauled to 
windward, mainsail hauled up, and mizen taken in; the galf 
topsail also hauled up ; she then drifts to leeward, and the 
dredge is thrown overboard to windward, with the line made 
fast amidships ; the spare line being coiled up so as to be given 
out readily. When the dredge is to be hauled in, the rope is 
passed through a movable block, fixed to the shrouds, and the 
whole strength of the crew (fifteen hands) called into requisition, 
if necessary. When the depth does not exceed 50 fathoms, the 
boat, with three men and the two dredgers, is used. 

If the dredge gets fouled, the rope is passed into the boat, 
brought over the dredge, and hauled up. In very deep water 
(150 fathoms) the line is carried forward and made fast to the 
bows, and the yacht itself hauled up till right over the dredge, 
which is then recovered without difficulty. 

The contents of the dredge are washed, and sifted with two 
sieves, one " j -inch," the other very fine. They are made of 
copper wire, and one fits into the other. The dredge is emptied 
into the coarse sieve and washed in the sea from the boat, or if 
in the yacht, they are placed in an iron frame, over the side 
of the vessel, and buckets of water poured on. The sediment 
retained in the fine sieve may be dried and examined at leisure, 
for minute shells. 

The following " dredging-papers," kept on the plan recom- 
mended by Professor E, Forbes, have been selected by Mr. 
Barrett, to illustrate the kind of shells found at various zones 
of depth. 

The shell-fish obtained by dredging should be at once boiled, 
and the animals removed, unless wanted for examination (p, 153), 
The bivalves gape, and require to be tied with cotton; the 
opercula of the univalves should be secured in their apertures 
with wool. The small univalves may be put up in spirit, or 
glycerine, to save time. In warm climates the flies and ants 
assist in removing any remains of the animals left in spiral 
shells, and chloride of lime may be necessary to deodorise them. 

M. Petit de la Saussaye has given very full instructions for 
collecting and preserving shells, in the Journal de Conchyliologie 
for 1850, p. 215, and 1851, pp. 102, 226. 

It is stated that both the form and colour of molluscous 
animals may be preserved in a saturated solution of hydro- 
chlorate of ammonia (10 parts) and corrosive sublimate (1 part 
— first dissolved in alcohol), but the preparation is expensive 
and dangerous. 



144 



MANUAL OF THE MOLLFSCA. 



DEEDQING PAPEES, AND EECOEDS OF EESEAECHES 
ON THE COAST OE NOEWAY. 

By E. McAndrew, Esq., aio) Lucas Baeeett, Esq., F.G.S. 



Date .. 
Locality 
Depth ... 
G-round . 



I. 

July 1st, 1855. 
Tromsoe (Nordland). 
Between tide marks. 
Rock and sand. 





Number 


Number 




Species. 


of living 


of dead 


Observations. 




specimens. 


specimens. 




Mya truncata 


6 


Many. 


In sand. 


Tellina incarnata 


Many. 


Many. 


In sand. 


Astarte compressa 


1 





On sand. 


borealis 


3 


Many.' "* 


On sand. 


Cardium edule 


Many. 


]Many. 


In sand. 


Crenella discors 


Many. 





Covering the under 
sides of stones. 


Acmaea testudinalis 


Many. 





On rock. 


Margarita nndulata 


6 





On weed. 


„ helicina 


8 





On w^eed. 


Littorina littorea 


Many. 





On rock. 


„ rudis 


Many. 





On rock. 


Lacuna vincta. 


2 





On weed. 


Natica pusilla 


2 





On sand. 


„ clausa 


Many. 





On rock. 


Purpura lapillus 


Many. 


Many. 


On rock. 


Buccinum undatum 


Many. 





On rock and saud. 


„ cyaneum 


Many. 





On rock. 


Bela turricula 


10 





On rock. 


Doris Jolmstoni 


8 








(Note.) No specimens of Trochus or Patella vulgata occurred. 



Date 

Locality 

Depth ... 

Distance from shore 
Ground 



II. 

July 5th, 1855. 

Near Hammerfest (Finmai'ken). 

7 to 20 fathoms. 

Close to shore. 

NuUipore and sand. 



Saxicava arctica 


4 





Young. 


Mya truncata 


4 


3 


Young. 


Thracia convexa 


4 





In sand. 


Tellina proxima 





4' 




Mactra elliptica 


I 







Venus ovata 


3 







„ striatula 


Many. 







Cyprina Islandica 


Many. 


Many.' 




Astarte compressa 


Many. 







Cardium fasciatum 


6 







Modiola modiolus 


1 


4' 




„ phaseolina 


3 








* The accented numbere in the colmnn ot " dead Bpecimens " refer to diBunited 
▼alves of Conchifera and 3racfiiopocta. 



■DISTEIBrXIOISr IN DEPTH. 



145 





Number 


Number 




Species. 


of living 


of dead 


Observations. 




specimens. 


specimens. 




Ledacaudata 




2 


1 




Pecten Islandicus ... 











2' 




Chiton asellus 








2 







„ marmoreus... 








2 







Acmsea virginea ... 








3 


2 




„ testudinaria 











1 




Patella pellucida ... 








6 







Dentalium entale ... 








4 


2 




Trochus tumidus ... 








Many. 


Many. 




„ cinerarius... 








1 







Margarita helicina... 








12 







„ undulata 








Many. 


Manj\ 




„ cinerea ... 








6 


2 




Velutina laevigata . . . 











1 




Buccinum undatmn 











3 




Trophon clathratus 








1 







„ GrUDueri ... 








1 







Belarufa 








1 







„ turricula 











4 




Mangelianana 








2 








III. 



Date 


.. . 


. .. 


... July 3rd 


, 1855. 




Locality Island of Amoe (Finmarken)., 


Depth 7 to 22 fathoms. 


Distance from shore ... Half amUe. 


Ground Laminaria and red weed. 


Saxicava arctica 




3 


Many.' 




Thracia convexa ... 






1 







Venus ovata 






1 


3' 




Cyprina Islandica ... 






2 


Many.' 




A^starte crebricostata 






Many. 


Many. 




„ elliptica . . . 






12 


Many. 




„ compressa . . . 






Many. 


Many. 




Cardium fasciatum 






Many. 


Many. 




Cryptodon flexuosus 






1 


6' 




Modiola modiolus ... 






1 


Many.' 




Crenella decussata. . . 






Many. 


Many. 




Ledapernula 






Many. 


Many. 




Pecten Islandicus ... 






3 


Fragments. 


Young. 


Anomia Ephippium 






Many. 







„ aculeata ... 






Many. 







Chiton marmoreus... 






4 







Dentalium entale . . . 






4 


Many. 




Trochus tumidus ... 






Many. 


Many. 




„ cinerarius ... 






Many. 


Many. 




Margarita cinerea ... 






Many. 


Many. 




„ undulata 






Many. 


Many. 




„ helicina... 


..> . 




Many. 


Many. 




Lacuna vincta 






Many. 


Many. 




Littorina littoralis ... 






3 







Rissoa parva 






Many. 







Naticaclausa 






4 







„ pusilla 









1 




Velutina laevigata ... 






3 







„ flexilis ... 






1 








H 



146 



MANUAL OF THE MOLLUSCA 



Species. 



Trichotropis borealis 
Nassa incrassata , 
Mangelia nana 
Bela turricula... 
Troplion Ginmeri , 
clathratus 



Number 

of living 

specimens. 



3 
1 

8 

Many. 

12 



Number 

of dead 

specimens. 



Observations. 



Date 

Locality 

Distance from shore 

Depth 

Oround 



lY. 

July. 1855. 

Vigten Island (N. Drontheim). 

Quarter of a mUe. 

30 fathoms. 

Coral-bank. 



Arcanodulosa 


3 


5 




Leda caudata 


2 







Yoldia lucida 


3 







Astarte succata 


3 


4' 




Pecten Islandicus 





2' 




Lima excavata 





1' 




Lucina Sarsii 





1 




• Cr}T)todon flexuosus 


2 







Modiola phaseolina 


10 







Anomia ephippium 


Many, 







Venus ovata 





2 




Terebratulina caput-serpentis . . . 


20 


Many. 




Chiton asellus 


4 







Puncturella noachina 


. 2 







Emarginula fissura 


1 


2 




cra^isa 





1 




Margarita cinerea 


1 







„ alabastrum 


1 







Trophon barvicensis 


1 








Date . 

Locality 

Depth 

Distance from shore 

Ground 

No. of hauls 



V. 

June 2.3rd, 1855. 
Omnaesoe (Nordland). 
30 to 50 fathoms. 
Half a mile. 
Stones and sand. 
Four. 



Saxicava arctica ... 
Tellina proxima ... 

Venus ovata 

Cyprina Islandica ... 
Astarte eUiptica ... 

„ compressa... 
Cardium fasciatum 

„ suecicum... 
Modiola phaseolina 
Crenella nigra... ... 

Nucula nucleua 

„ tenuis - 

Leda caudata 

Area pectiuicu^oides 




2 
2 
4 
6 
2 
5 
200 


4 
2 
12 



2 

1 


Many. 







4' 
Manj-, 

1 

5 
Many, 


10' 



Small, 



Large. 
Laige. 



L&rge« 



DISTIIIBTJTION IN DEPTH. 



147 



Species. 



Pecten striatus 

„ tigrinus 

„ sirnilis 

„ Islandicus 

Terebratula cranium 

Terebratulina caput*sei'pentis 
Crania anomala ... ... ... 



Chiton Hanleyi 

Lepeta ccEca 

Acmsea virginea 

Pilidiuna f ulvum *" 

Puncturella noacliina , . . 
Trochus millegranus . . . 

Eulima polita 

Natica nitida 

„ helicoides 

„ pusilla 

Velutin a laevigata 

Trichotropis borealis . . . 

Nassa incrassata 

Fusus aatiquus 

Trophon clathratus 

Mangelia tuiTicula 

Tornatella fasciata 
Buccinum undatum 
Pleurotoma nivalis 



Number 

of living 

specimens. 



2 
3 
1 


80 
1 

12 



3 

4 
10 
Many. 
2 
2 
1 
3 


I 
6 
1 



1 



6 

10 



Number 

of dead 

specimens. 




6 

1' 
10 







6 
4 
1 


2 
1 
1 

3 

2 
1 

2 

15 



Observations. 



Large and Eecent. 



Many stones had on 
them the attached 
valve. 



Large. 
Carinated Var. 

Young. 



Date 

Locality ... ... 

Depth 

Distance from shore 

Ground 

No. of Hauls 



VI. 

, July 20th, 1855. 

North of Eolphsoe (Finmarken)* 

130 to 180 fathoms. 
, Half a mile. 

Sand. 
, Two. 



Cyprina Islandica 





3 




Nesera cuspidata 





2' 




Leda caudata 





3' 




Yoldia lucida 


1 


2' 




Pecten Islandicus 





Many. 


Small. 


„ similis 





1 




Area pe.ctunculoides ... ... ... 


1 







SjTidosmya prismatica 





I 




Crj'ptodon flexuosus 





1 




Mactra elliptica 





2"6' 




Cardium fasciatum 





2 




„ suecicum 





3 




Astarte sulcata 


I 







Anomia ephippium 


Many. 







Crenella decUiSsata 


2 


Many. 




,. nigra 





2' 




Terebratula cranium 


3 







Ehynchonella psittacea 


1 


2 




Dentalium entale 


Many. 


Many. 




Punctm-ella noachina 


MaTiy. 







Lepetacoeca 


2 







Pleurotoma nivalis 


I 


2 





H 2 



148 



MANUAL OF THE MOLLTTSCA. 



Species. 


Number 

of living 

specimens. 


Number 

of dead 

specimens. 


Observations. 


Fusus? sp. ... 

Buccinum Humphrej^sianum . . . 

Bela turricula 

Margarita cinerea 

„ undulata 

„ alabastrum 




2 
3 




Fiy. 

1 

4 
2 

1 





Date 

Locality 

Depth 

Distance from shore , 
Ground 



YII. 

July 25th, 1855. 

Off the Island of Arniie (Finmarken). 

200 fathoms. 

Four miles. 

Mud. 



Pecten similis 





2' 




Cryptodon flexuosus 


4 







Nesera cuspidata 





1 




Area pectunculoides 


1 


3 




Nucula tenuis 


2 







Yoldialucida 


4 


6 




Modiola phaseolina 


2 







Cardium suecicum 


2 







C'renella decussata 


1 







Astai'te crebricostata 





4.- 




Terebratula cran ium 





2 




Dentalium entale 


1 


2 




.. sp 


1 


8 




„ quinquangulare (Forbes) 


1 







Eulima bilineata 


2 


2 




Eulimella Scillse 





3 




MangeUa trevelliana ... 





1 




Bela iTifa 





1 




Philine quadrata 





1 





BEEDGINQ PAPEES, OE EECOEDS OF EESEAECHES 
IN THE ^GEAN SEA. 

By Pbofessor E. Eorbes. 



Date 

Locality 

Distance from shore 

Depth 

Ground 



I. 

May 29th, 1841. 
Nousa Bay, Paros. 
Within the Bay. 
6 to 6 fathoms. 
Mud and sandy mud. 



Pinna squamosa 





1 




Modiola tulipa 


1 





In sandy mud. 


Pecten polymorphus ... 


4 


6' 




„ hyaltnus 


1 







Nucula margaritacea 





40' 


In dark mud. 


Cytherea chione 





1 




„ venetiana 


1 


3-5' 




„ apicalis 


1 


2-12' 





DISTRIBUTION IN DEPTH. 



149 



Species. 



Artemis lincta 
Tapes virginea 
Venus verrucosa ... 
Tellina donacina ... 

„ balaustina... 
Syndosmya alba ... 
Lucina lactea 

„ squamosa ... 

„ rotundata ... 
Cardium rusticiim ... 

„ exiguum ... 
Cardita sulcata 
Patella scuteUaris ... 

Calyptraea Sinensis 

Bulla hydatis 

Turi-itella 3 plicata. . . 
Trochus canaliculatus 
Cerithium lima 

„ vulgatum 
Murex fistulosus . . . 
Aplysia depilans ... 
Ostifea plicatula ... 



Number 

of living 

specimens. 







12 
1 
1 




Number 

of dead 

specimens. 



Observations. 



1' 

5' 

6' 

1-3' 

2' 

2-10' 

2-28' 

3' 

4' 

1' 

7' 

1' 

1 

2 
1 
1 

4 
3 
8 


10' 



A strong valve. 



Washed in from,,, 
shore. 



In dark mud. 



Date 

Locality 

Depth 

Distance from shore 
Ground 



II. 

Sept. 14th, 1842 
Gulf of Smyrna. 
26 fathoms. 
Two miles and a half. 
Fine brovrn mud. 



Avicula Tarentina , 
Saxicava arctica . 




Full grown, adhering 
to each other. 



^ate 

Locality 

Depth 

Distance from shore 
Ground 



III. 

August 5th, 1841. 

Off northern extremity of Paros. 

40 fathoms. 

Three miles and a half. 

Weedy. 



Pectenpusio 


5 


4' 




„ opercularis 





1 


Small. 


Nucula margaritacea 





2' 




Cytherea apicalis 





1' 




Cardita squamosa 


1 


1' 




Cardium papillosum 





2 




Fusus fasciolaroides 


1 





New, 


Murex brandaris 





3 




Vermetus gigas 





1 




„ corneus 


3 





New. 


Trochus exiguus 


8 


2 




Turbo rugosus 


1 







Pleurobranchus sordidus 


1 





New. 


Doris tenerrina 


2 




New. 


„ gracilis 


2 






„ coccinea 


1 






Ascidium, four species 








Aplidium, two species 









15Q 



MANUAL OF THE MOLLTJSCA. 



Date , 

Locality 

Depth 

Ground 

Distance from shore 



lY. 

Sept. 16th, 1841. 
Off Ananas Eocks. 
105 fathoms. 
Nullipore. 

From Eocks three miles, from Milo ten miles. 





Number 


Number 




Species. 


of living 


of dead 


Observations. 




specimens. 


specimens. 




Terebratnla vitrea 





2' 


Dead and worn. 


Megerlia truncata 


30 


100-20' 


Of all ages. 


Argiope decollata 


100 


400-6' 


Of all ages. 


„ seminulum 


18 


10-8' 




Morrisia anomioides 


1 





Adhering to T. vitrea. 
New. 


Crania ringens 





6' 




Lima elongata 





5' 


New. 


Pecten concentricus 





I' 


New. 


„ fenestratus 





2' 


New. 


Spondylus Giissoni 


1 


1' 




Ajcalactea 


1 


7' 




„ scabra 





2' 




Neaera cuspidata 





1' 




„ attenuata 





1' 


New. 


Fusus echinatus 





2 




Pleurotoma crispata 





2 


Hithei-to known only 
fossil. 


„ maravignse 





2 


New. 


„ ^byssicola 





4 


New. 


Mitra philippiana 





4 


New. 


Cerithium hma 





8 




Trochus tinei ... '. 





6 




„ exigiaus ., 


1 


9 




Turbo saqgiiineus 





24 


Hitherto knovm only 
fossil in the Medi- 
terranean basin. 


Eissoa reticulata 


4 


11 




Emarginula elongata 





8 




Pileopsis Hungaricus 





1 


SmaU. 


Acmgea unicolor 


1 


24 


New. 


Atlanta Peronii 





2 


Incrusted with nul- 
lipore, and thus 
rendered solid. 


Hyalea gibbosa 





r 




rieodora pyramidata 





3 


' 


Criseis clava ... ., 





7 




„ spinifer^ ., 





10 





Date 

Locality 

Depth 

Distance from shore 
Ground 



V. 

Nov. 25th, 1841. 

S. extremity of Gulf of Macn. 

230 fathoms. 

One mile (shore steep). 

Fine j'ellowish mud. 



Terebratula vitrea 

Syndosmya profundissima 

Area imbricata 

Dentalium quinquangulare 

Hyalea gibbosa 

Cleodora pyramidata . . . 
Criseis spinifera 



DISTEIBUTION IN DEPTH. 151 

The distribution of the MoUusca in Depth has been investigated 
by MM. Audouin and Milne-Edwards, M. Sars, and Professor 
E. Forbes. By these observers the sea-bed is divided into four 
principal regions : — 

1. The Littoral zone, or tract between tide marks. 

2. The Laminarian zone, from low water to 15 fathoms. 

3. The Coralline zone, from 15 to 50 fathoms. 

4. The deep-sea coral zone, 50 to 100 fathoms or more. 

1 . I'he Littoral zone depends for its depth on the rise and fall 
of the tide, and for its extent on the form of the shore. The 
shells of this zone are more limited in their range than those 
which are protected from the vicissitudes of climate by living 
at some depth in the sea.* In Europe the characteristic genera 
of rocky shores are Littorina, Patella, and Purpura; of sandy 
beaches, Cardium, Tellina, Solen ; gravelly shores, Mytilus ; 
and on muddy shores, Lutraria and Pullastra. On rocky coasts 
are also found many species of Haliotis, Siphonaria, Fissurella, 
and Trochus ; they occur at various levels, some only at the 
high-water line, others in a middle zone, or at the verge of 
low-water. Cyprcea and Co7ius shelter under coral-blocks, and 
Gerithium, Terehra, Natica, and Pyramidella bury in sand at low 
water, but may be found by tracing the marks of their long 
burrows. (Macgillivray.) 

2. Laminarian zone. — In this region, when rocky, the tangle 
[Laminarici) and other sea-weeds form miniature forests, the 
resort of the vegetable feeding moUusks — Lacuna, Bissoa, Nacella, 
Trochus, Aplysia, and various Nudihranchiata. On soft sea-beds 
bivalves abound and form the prey of Buccinum,, Nassa., and Natica. 
Erom low-water to the depth of one or two fathoms on muddy 
and sandy shores, there are often great meadows of grass- wrack 
[Zostera) which afford shelter to numerous shell-fish, and are 
the haunt of the cuttle-fish and calamary. In tropical seas, the 
reef-building corals often take the place of sea-weeds, and 
extend their operations to a depth of about 25 fathoms. They 
cover the bottom with living verdure, on which many of the 
carnivorous mollusks feed, while some, like Ovt^Zwrnand Purpura, 
browse on the flexible Gorgonice. To this zone belong the 
oyster-banks of our seas, and the pearl-fisheries of the south ; 
it is richer than any other in animal life, and affords the most 
highly coloured shells. 

Some of the littoral shells, like Purpura lapillus and Littorina rudis, have no 
free-swimming larval condition, but comn>'"»'"e life as crawlers, with a well'developed 
shell. Their habits are sluggish, and tneir diffusion by ordinary means must be 
exceedingly slow. 



152 MANUAL OF THE MOLLFSCA. 

3. Coralline zone. — In northerii seas the belt of sea- weed that 
fringes the coast is succeeded by a zone where horny zoophytes 
abound, and the chief vegetable growth consists of Nullipore, 
which covers rocks and shells with its stony-looking incrusta- 
tions. This zone extends from 15 or 25, to 35 or 50 fathoms, 
and is inhabited by many of the predacious genera — Buccinum, 
Fusus, Fleurotoma, Natica, Aporrhais, Philine, Velutina ; and by 
vegetable feeders, such as Fissurella, Fmarginula, Fileopsis, 
FuUma, and Chemnitzia. The great banks of scallops belong 
to the shallower part of this region, and many bivalves of the 
genera Lima, Area, Nucula, Astarte, Venus, Artemis, and Corbula. 

4. Beep-sea Coral-zone. — ^From 50 to 100 fathoms the Nullipore 
still abounds, and small branching corals to which the Tere- 
hratula adhere. In northern seas the largest corals {Oculina 
and Primnoa) are found in this zone, and shells are relatively 
more abundant, owing to the uniformity of temperature at these 
depths. These deep-water shells are mostly small and destitute 
of bright colours ; but interesting from the circumstances under 
which they are found, their wide range, and high antiquity. 
Amongst the characteristic genera are Crania, Thetis, Necera, 
Cryptodon, Yoldia, Bentalium, and Scissurella. In the mud 
brought up from deep water may be often found the shells of 
Pteropoda, and other mollusca which live at the surface of the 
sea. In the ^gean Sea there is deep-water within one or two 
miles of the coast ; but in the British Channel the depth seldom 
amounts to more than 20 — 40 fathoms. 

When registering the results of dredging operations, it is 
important to distinguish between dead and living shells, as in the 
preceding Tables ; for almost every species is met with, in the 
condition of dead shells, at depths far greater than those in which 
it actually lives. On precipitous coasts the littoral shells fall 
into deep water, and are mingled with the inhabitants of other 
zones ; currents also may transport dead shells to some distance 
over the bed of the sea. But the principal agents by which so 
many decayed and broken shells are scattered over the bed 
of the deep-sea, must be the mollusk-eating fishes. Of 270 
species of boreal shells described by Dr. Grould (p. 60) more 
than half were obtained from the maws of fishes, in Boston 
market. Cod-fish do not swallow the large whelk-shells, but 
some idea of the number they consume may be derived frpm 
the fact that Mr. "Warington has obtained the muscular foot 
and operculum of above 100 whelks, of large size, besides 
quantities of Crustacea, from the maws of three cod-fish procured 
in the London market. Bivalve shells, like the Solens, and the 



DISTRlBtJTlON m DEPTH 



153 



rare Pcmopcea Norvegica are swallowed, and ejected again with 
eroded surfaces. The haddock swallows shells still more indis- 
criminately, and Mi\ M 'Andrew has found great numbers of 
rare Pectens in them, but generally spoiled. The cat-fish and 
skate break up the strongest shell-fish with their teeth — -account- 
ing for the many angular fragments met with in the dredge, 
and in recent deposits. 

The following are examples of shells obtained from great 
depths : — 



Nonoay. (M'Attdrev 
Living shells. 




rathoms. 

20—150 

10-^130 

200 

120 

200 

120 

40^100 

200 

136 
132 
120 

Dead. 

250 
110 
150 


Mgmn, (Forbes. 
Murex vagin attis 


) 

Living, 

80-96 
8—80 

hh 
10—105 

60—106 
are 

105 

90--230 
12—185 

70—180 
aa 


Dead. 
150 


Cerithium metula .>..>).>•••• 


Fusus mUricatus ...,.,... 


150 


Margarita cinerea ...>m">i.. 


Na? sa intermedia 

Cerithium lima 


45—185 






140 






Chemnitzia fasciata ... 
Eulima distorta 


110—150 






69—140 


Yoldia, limatula 




Scalaria hellenica 

Rissoa reticulata 

Trochus exasperatUs .. 

Scissurella plicata 

Acmea unicolor 

Dent all jm quinquangul 
Bulla Utriculus . . .. 


110 
185 


Cryptodon flexuosus 




165 


Off the Cape. (Belcher.) 
BuccitiumP clathratiun. 


70—150 

150 

150—230 


Volutilithes abyssicola 

Pectunculus Belcheri 

.Mgean^ (i'orbesO 


100 

100 

&0 


40—140 


Spondylus Gassonii .. 
Pecten Hoskynsii 
Area imbricata 


185-200 


Liv 

Terebratula vitrea 

Argiope decollata 

Crania ringens , 


Neaera cuspidata 

Tlietis anatinoides 

Kellia abyssicola . ..„. 
Syndosmya prof undissiE 


40—150 

200 

80-185 



Preserving molluscous animals for examination. 

When shell^fish are killed by sudden immersion in hot watej? 
or strong spirit, great and unequal contraction is caused, dis- 
torting the muscular parts and rupturing the membranes. 

Experiments have yet to be made for the discovery of means 
whereby these and other marine animals may be paralysed and 
killed, without altering the ordinary condition of their organs.* 

Glycerine is the best medium for preserving such objects as 
the univalve shell-fish, intended for the examination of their 

* The brittle'Stars {Opkmcoma) are killed by audden immersion in fresh-water; and 
the Actiniee may be stupifled by adding fresh* water drop by drop until they lose the 
power of retracting their tentacles. But the bivalves (such as Pholas) may be kept in 
stale water till their valves fall off with incipient decomposition, and yet the muscular 
siphons retain theu- irritability, and contract slowly and completely, when placed in 
spirit. 

h3 



154 MllfTTAL OF THE MOLLtTSCA 

lingual teetK ; for if put up in strong spirit they become so 
hard that it is almost impossible to make good preparations from 
them, and in weak spirit they will not keep for any length of 
time. 

Alcohol,— The cheapest alcohol for preserving natural history 
objects, at home, is sold as " methylated spirit;" it contains ten 
per cent, of ordinary wood spirit, and being undrinkable, is free 
of duty. When many specimens are put up together the spirit 
becomes much diluted, and should be changed. The soft tissues 
of bivalves, and spiral bodies of the univalves soon decompose 
in weak spirit. But for permanent use, in Museums, proof 
spirit may be diluted with an equal bulk of water. Cotton wool 
may be put with the specimens in spirit, especially with cuttle- 
fish, to preserve them from distortion by pressure. 

Ooadhy's solution is prepared by dissolving | lb. of bay salt, 
20 grains of arsenious acid, or white oxide of arsenic, and 2 
grains of corrosive sublimate, in 1 quart of boiling rain-water. 

Burnefs solution (chloride of zinc), largely diluted, is now 
used at the British Museum for the preservation of fishes and 
other objects, in glass jars. It has several advantages over 
spirit ; being undrinkable, and not inflammable, and the con 
centrated solution (sold by all druggists) is much less bulky. 

Muriate of Ammonia is recommended by Mr. Gaskoin, for 
removing any unpleasant odours which may arise from prepara- 
tions when taken out of spirit for examination. (See p. 143.) 

A solution of Chloride of Oalcium has been employed by 
General Totten, United States Engineers, for preserving the 
flexibility of the epidermis in various shells. The solution of 
this deliquescent salt (which any one can make, by saturating 
hydrochloric acid with marble) keeps the object which has been 
steeped in it permanently moist, without injuring its colour or 
texture ; while its antiseptic properties will aid in the preserva- 
tion of matters liable to decay. (Professor J. W. Bailey, in 
SilUman'e Journal^ July, 1854.) 



PART II. 

SYNOPSIS OF THE GENEEA.. 



Chapter I. 

(TLASS I.-CEPHi^LOPODA, 

The cephalopoda are represented by tlie common squid, tlie 
nautilus, and the ammonite ; forms witli which most of us are 
more or less familiar. They possess a more complicated struc- 
ture than any other group of the mollusca ; but in this respect 
they are much inferior to the vertebrate animals, in whom 
the setting apart of particular organs for the performance of 
distinct functions is developed to so high a degree. We cannot 
trace a series of gradational forms between the highest cepha- 
lopod and the lowest vertebrate ; but we can descend from the 
more to the less specialised forms of mollusca, which ultimately 
merge in one direction in such creatures as Fasciola, among 
entozoa; and in another direction, to forms like Vorticella, 
through the intermediate genera — Pedicellina, among the 
Bryozoa, and Perophora among the Ascidians. It is conse- 
quently much easier to define the higher than the lower 
boundaries of a great primary group. The points of analogy 
between the cephalopods and the vertebrates are the internal 
skeleton, the similarity in the form of the blood corpuscles, and 
in the capillary structure of the portion of the circulatory 
system situated between the arteries and veins. 

The cephalopods move partly by means of a series of long 
muscular arms arranged round the mouth, partly by means of 
fins, or flaps, attached on each side of the body, and partly by 
the forcible expulsion of water through a tube or siphon. 

Unlike most of the mollusca, they are symmetrical animals, 
having their right and left sides equally developed. Their shell 
is usually straight, or coiled in a vertical plane. The nautilus 
and argonaut alone (of the living tribes) have external shells ; 
the rest are termed " naked cephalopods," because the shell is 
internal. They have powerful jaws, acting vertically, like tht 



156 



MANUAL or THE MOLLUSCl. 



mandibles of birds. The tongue is large and fleshy ; part of its 
surface is sentient, whilst the rest is armed with recurved spines ; 
their eyes are large, and placed on the sides of the head. In all 
probability they possess the faculty both of smelling and hearing. 
All are carnivorous, and live in the sea. 

The nervous system is more concentrated than in the other 
moUusca, and the brain is protected by a cartilage. The respira- 
tory organs consist of two or four plume-like gills, placed 
symmetrically on the sides of the body, in a large branchial 
cavity, opening forwards on the under* side of the head : in the 
middle of this opening is placed the siphon or funnel. The sexes 
are always distinct. The cephalopoda are divided into two 
orders, the names of which are derived from the number of the 
hrancJiice. 

Oeder I. — ^DiBRAK-CHiATA, Owen. 

Animal swimming; naked. Head distinct. Eyes sessile, 
prominent. Mandibles horny (PL I., fig. 2). Arms eight or 
ten, provided with suckers. Body round or elongated, usually 
with a pair of fins ; hranchice two, furnished with muscular 
ventricles ; ink-gland always present ; funnel a complete tube. 

Shell internal (except in argonauta), horny or shelly, with or 
without air-chambers. The shell of the argonaut does not 
correspond with the ordinary shell of mollusks. (See p. 39.) 

The typical forms of the cuttle-fishes were well described by 
Aristotle, and have been repeatedly examined by modem 
naturalists ; yet, until Professor Owen demonstrated the exist- 
ence of a second order of cephalopods, departing from all the 
above-mentioned characters, it was not clearly understood how 
inseparably the organisation of the cuttle-fishes was connected 
with their condition as swimming mollusca, breathing by tivo 
gills. There are two types of lung structure among the dibran- 
chiates. Thus, in Octopus and Sepia the gills form a cylinder, 
while in Loligo and other genera they form a half cylinder. 

The characters which co-exist with the two gills, are the 
internal rudimentary shell, and the substitution of other means 
of escape and defence, than those which an external shell would 
have afforded ; viz. , powerful arms, furnished with suckers ; the 

* According to the established usage, we designate that the binder or ventral side of 
the body, on which the funnel is placed. But if the cuttle fishes are compared with 
the nucleobranchs, or the nautilus with the holostomatous gasteropoda, their external 
analogies seem to favour an opposite conclusion. There are many terms in use which 
are apt to mislead, such as fins, arms, &c. ; they have a definite meaning when applied 
to the vertebrata, but not so when applied to the invertebrata. 



CEPHALOPODA. 157 

Becretion of an inky fluid, with whicli to cloud the water and 
conceal retreat ; more perfect organs of vision ; and superadded 
branchial hearts, which render the circulation more vigorous. 

The suckers [antlia or acetahula) form a single or double series 
on the inner surface of the arms. Prom the margin of each 
cup, the muscular fibres converge to the centre, where they 
leave a circular cavity, occupied by a soft caruncle, rising from 
it like the piston of a syringe, and capable of retraction when 
the sucker is applied to any surface. So perfect is this mechanism 
for effecting adhesion, that while the muscular fibres continue 
retracted, it is easier to tear away the limb than to detach it 
from its hold. * In the decapods, the base of the piston is sur- 
rounded by a horny dentated hoop ; which in the uncinated 
calamaries is folded, and produced into a long sharp claw. 

The ink-lag (Fig. 40) is tough and fibrous, with a thinsil very 
outer coat; it discharges its contents through a duct which 
opens near the base of the funnel. The ink was formerly used 
for writing [Gicero), and in the preparation of sepia,-^' and from 
■its indestructible nature, is often found in a fossil state. 

The skin of the naked cephalopods is remarkable for its 
variously coloured vesicles, or pigment-cells. In sepia they 
are black and brown ; in the calamary, yellow, red, and brown ; 
and in the argonaut, and some octopods, there are blue cells 
besides. These cells alternately contract and expand, by which 
the colouring matter is condensed or dispersed, or perhaps 
driven into the deeper part of the skin. The colour accumulates, 
like a blush, when the skin is irritated, even several hours after 
separation from the body. During life these changes are under 
the control of the animal, and give it the power of changing its 
hue, like the chameleon. In fresh specimens, the sclerotic plates 
of the eyes have a pearly lustre ; they are sometimes preserved 
in a fossil state. 

The aquiferous pores are situated on the back and sides of the 
head, on the arms {brachial), or at their bases [buccal pores). 

The mantle is usually connected with the back of the head by 
a broad (" wwcAaZ ") muscular band; but its margin is some- 

* " The complex, irritable mechanism of all these suckers is under the complete 
control of the animal. Mr. Broderip informs me that he has attempted, tvith a hand^ 
net, to catch an octopus that was floating by, with its long and flexible arms entwined 
round a fish, which It was tearing with its sharp hawk's bill ; it allowed the net to 
approach within a short distance before it relinquished its prey, when, in an instant, it 
relaxed its thousand suckers, exploded its inky ammunition, and rapidly retreated, 
under cover of the cloud which it had occasioned, by rapid and vigorous strokes of ita 
circular web." — Owen, 

t Indian ink and sepia are now made of lamp-smoke, or of prepared charcoal. 



158 MANUAL OF THE MOLLTJSCA. 

times free all round, and it is supported only by cartilaginous 
ridges, fitting into corresponding grooyes, and allowing con- 
siderable freedom of motion. 

The cuttle-fishes are generally nocturnal, or crepuscular 
animals, concealing themselves during the day, or retiring to a 
lower region of the water. They inhabit every zone, and are 
met with near the shore, as well as in the open sea, hundreds of 
miles from la.nd. The}'' attain occasionally a much greater size 
than any other moUusca. MM. Quoy and Gaimard found a dead 
cuttle-fish in the Atlantic, under the equator, which must have 
weighed 2 cwt. when perfect; it was floating on the surface, 
and was partly devoured by birds. Banks and Solander also 
met with one under similar circumstances in the Pacific, which 
was estimated to have measured six feet in length. (Owen.) 
The arms of the octopods are sometimes two feet long.* Erom 
their habits, it is difficult to capture some species alive, but 
they are frequently obtained, uninjured, from the stomachs of 
dolphins and other cetaceans which prey upon them. 

Section A. — Ogtopoda. 

Arms, eight ; suckers sessile. Eyes fixed, incapable of rotation. 
Body united to the head by a broad cervical band. Branchial 
chamber divided longitudinally by a muscular partition. Oviduct 
double ; no distinct nidamental gland. Shell internal and 
rudimentary. 

The Octopods difi'er from the typical cuttle-fishes in having 
only eight arms, without the addition of tentacles ; their bodies 
are round, and they seldom have fins. 

The males and females have a general resemblance to each 
other ; although the form and appearance of the sexes are very 
distinctive. But until recently our knowledge on the subject 
has been confused. In all male cuttle-fishes one of the eight 
arms presents a peculiar appearance and undergoes a special 
development, fitting it for the pm'pose of helping forward the 
work of reproduction of the species. In many cases it is so 
altered as to be incapable of acting as a locomotive organ. 
According to Dr. Mtiller, the arm is detached, after it has been 
filled with semen, and is fixed on to the female. The arm, or 
whatever it may be that is so attached, was formerly mistaken 

* Denys Montfort, having represented a " kraken octopod," in the act of scuttling a 
three-master, told M. Defrance that if this were " swallowed," he would in his next 
prtition represent the monster embracing the Straits of Gibraltar, or capsizing a whole 
Bqua<Jron of ships. (D'OrbiKuy). 



CEPHALOPODA. 150 

for a parasitic worm ; and more recently it lias been regarded, 
as tlie spermatophore by some, and as the entire male animal 
by other naturalists, under the name of hectocotylus. The 
hectocotyle of tremoctopus is shown in Fig. 3, PI. I. The body 
is worm-like, with two rows of suckers on the yentral surface, 
and an oval appendage at the posterior end. The anterior part 
of the back is fringed with a double series of branchial fila- 
ments (250 on each side). Between the filaments are two rows 
of brown or violet spots^ like the pigment cells of the tremoctopus. 
The suckers (40 on each side) closely resemble those of the 
tremoctopus^ in miniature. Between the suckers are four or 
five series of pores, the openings of minute canals, passing into 
the interior part of the body. There is an artery and vein on 
each side, giving branches to the branchial filaments, while 
a nerve runs down the centre. The oval sac encloses a small but 
very long convoluted tube, ending in a muscular sac containing 
spermatozoa. 

The hectocotyle of the argonaut was discovered by Chiaje, who 
considered it a parasitic worm, and described it under the name 
oi trichocephalus acetabularis ; it was again described by Costa,* 
who regarded it as "a spermatophore of singular shape ; " and 
lastly by Dr. Kolliker.f 

It is similar in form to the others, but is only seven lines in 
length, and has a filiform appendage in front, six lines long. 
It has two rows of alternate suckers, 45 on each side ; but no 
hranchice; the skin contains numerQus changeable spots of red 
or violet, like that of the argonaut. | (Kolliker.) 

It would seem strange how former observers could have 
overlooked so marked a feature as the metamorphosed or hecto- 
cotylised arm. of cuttle fishes. Aristotle not only gives a clear 
description of the peculiarity, but even shows that he was aware 
of the function the arm performed. Subsequent writers appear 
to have misunderstood Aristotle ; at any rate they refer to the 
colourless arm as a monstrosity, or in some cases they have 
used it as one of the distinctive characters of a species. There 
are numerous instances in which the male has formed one, and 
the female another species in the naturalist's catalogue. Now 
that the hectocotylus is known to be only a portion of the male, 
their relation is more clearly seen. They present an analogous 
phenomenon to what occurs in some species of spiders, in which 

* An. Fc. Nat., 2nd series, 7, p. 173. 

t I^in- Trans., vol. 20, pt. 1, p. 9 ; and in Ilia own zootomical Berichte, where it is 
figured. 
X An. Sc. Nat,, 2nd series, vol. 16, p. 185. 



.160 



MAKtAL OF THE MOLLtJSCA. 



certain parts of the palpi of tlie maJes are developed into spoon- 
shaped organs which perform the same offi.ce as the hecto- 
cotylus. Something similar also occurs in Polydesma. 

Madame Power appears to have made her observations on 
an hectocotylus when she asserted that the yonng argonaut has 
no shell. M. Duvernoy has shown that the embryo argonaut 
has acquired a shell before it has been excluded from the eg^. 

The most important memoir on the development of Cepha- 
lopods is that by Kolliker. * ' ' The process of yolk division is 
partial, and the development of the embryo takes place within 
a distinct germinal area, whence a distinct yolk sac is formed. 
This, is proportionally very large in Sepia (Fig. 35), and 
Loligo, very small in Argonauta .(Fig. 36), and therefore while 
the embryo is jflattened and extended in the former genera, in 
the latter it more resembles the embryo of an ordinary gas- 
teropod. Development commences by the separation of the 




Fig. 33. Development of the Cuttle-fish. (KiiUiker). 

Ai Einbl^^o two lines in diameter; m, mantle; b, branchial processes; s, siphonal 

processes ; a,, mouth ; e, eyes ; 1 — n, rudimentary ai'ms. 
JB, Side view of the embryo, when more developed. 

C, Front view, at a later period. 

D, Young cuttle-fish, still attached to the yolk-sac, With the tentacular arms (2) 

longer than the rest. 

embryo into mantle and hody (foot). The part of the body in 
front of the mantle becomes the head; that behind it the 
branchio-anal surface. The latero-posterior margins of tho 
body are produced into four or five processes on each side, 
which become the arms. On each side of the mantle, between 
it and the head and arms, a ridge is formed upon the body. 
These ridges [s s, Fig. 35, a), represent the eptpodium; their 

* Entwickelungs-geschichte der Cephalopoden, Zurich, 1844. 



CEPHALOPODA. 



161 



anterior ends are continuous and attaclied ; the posterior ends 
are at first free, but eventually uniting they form the funnel 
D s. The rudimentary gills h appear between the epipodium 
and mantle. The alimentary canal is at first straight; (the 
mouth being at a, the vent at &, in Fig. 35 a). The embryo 
now grows faster in a vertical than in a longitudinal direction, 
so that it takes on the cephalopodio 
form. The intestine, as a consequence, 
becomes bent upon itself; and the and 
terior pair of arms grow over in front 
of the head, and unite, so as eventually 
to throw the mouth nearly into the 
centre of the arms." (Huxley.) At a 
later period of development (Fig. 35, d), 
the respiratory movements are per- 
formed by the alternate dilatation and 
contraction of the mantle ; and the ink- 
bag is conspicuous by the colour of its 
contents. At the period of exclusion 
from the nidimental capsule, fine layers 
of the shell of the young cuttle-fish 
have been formed; but except the 
nucleus, which is calcified, they are 
horny and transparent. The lateral 
fins are broader than in the mature animal. The embryo of 
the Argonaut, as described by Kolliker, has simple conical 
' arms (1 — 4, Fig. 36) ; and indications of the funnel appear as 
a ridge, p, on each side of the body ; v is the yolk sac ; o the 
position of the future mouth ; e the eye ; 6 the gill ; and m the 
mantle. 




Fig. 36. Argonaut, embryo 
in the egg. 



Family I. — ^AEGON-AUTiDiE. 

Dorsal arms (of the female) webbed at the extremity, secreting 
a symmetrical involuted shell. Third left arm in male hecto- 
cotylised; deciduous, colourless, developed in a sac. Female 
polyandrous. Mantle supported in front by a single ridge on 
the funnel. 



Genus AEXJOifAirTA, Lin. Argonaut, or paper sailor. 

Etymology, argonautai, sailors of the ship Argo. 
Synonyms, ocythoe (Eafinesque). Nautilus (Aristotle and 
Pliny). 



102 MANUAL OF THE MOLLUSCA. 

Example, A. Hans, Soland. PL II., Fig. 1. Cliina. 

Tlie shell of tlie argonaut is thin and translucent ; it is not 
moulded on tlie body of tlie animal, nor is it attached by sbell- 
mu.scles ; and tbe unoccupied hollow of the spire serves as a 
receptacle for the minute clustered eggs. The shell is believed 
to be peculiar to the female. Its spacial function is for protec- 



Fig. 37. Argonauta argo L, swimming.* 

tion and incubation of the eggs. It is not homologous with 
the chambered or internal rudimental shells of other cephalo- 
pods, but may be compared with the cocoon of the leech, or the 
float of lantliina. The argonaut sits in its boat with its siphon 
turned towards the keel,t and its sail-shaped (dorsal) arms 
closely applied to the sides of the shell, as in Eig. 37, where, 
however, they are represented as partially withdrawn, in order 
to show the margin of the aperture. It swims by ejecting 
water from its funnel, and crawls in a reversed position, carry- 
ing its shell over its back like a snail. (Madame Power and 
M. Eang.) 

The male argonauts are one inch in length, and possess no 
shell ; their dorsal arms are pointed, not expanded. The testis is 
large, and like that of the Octopus in structure and situation ; 
it contains spermatozoa of different degrees of development, 
and the excretory duct probably debouches into the Hecto- 
cotylus. The sac in which the Hectocotylus is developed is 
cleft by the movements of the Hectocotylus in extending 
itself, while the sac becomes inverted, and forms the violet 
coloured capsule on its back. The sac never contains more 
than one Hectocotylus, which is attached by its base, whilst 

* Froin a copy of Eang's figure, in Charle&wortK' s Magazine; one-fourth the 
natural size ; the small arrow indicates the current from the funnel, the large arrow 
the direction in which the "sailor " is driven by the recoil. 

t Poli has represented it sitting the opposite way; the writer had once an argonaut 
eTiell with the nucleus reversed, implying that the animal had turned quite round in its 
eliell, and remained in that position. The specimen is now in the York Museum. 



CEPHALOrODA 163 

the rest is free and coiled up. It lias no enlargement like that 
of the Tremoctopus (PL I., Fig. 3); the filiform appendage 
proceeds from the smaller extremity, and sometimes remains 
entangled in the coloured cyst near the base of the outer side 
of the Hectocotylus. It has a chain of nervous ganglia in its 
axis. 

It was the nautilus {'primus) of Aristotle, who described it as 
floating on the surface of the sea, in fine weather, and holding 
out its sail-shaped arms to the breeze. It does not use its arms 
as sails, but it sometimes uses them as oars when it wishes to 
progress slowly, while floating on the surface of the sea. 

Distribution : 4 species of argonaut are known ; they inhabit 
the open sea throughout the warmer parts of the world, and 
are most active during the night. Captain King took several 
from the stomach of a dolphin caught upwards of 600 leagues 
from land. 

Fossil, 2 species. Tertiary. A. Mans is found in the sub- 
apennine tertiaries of Piedmont. This species is still living in 
the Chinese seas, but not in the Mediterranean. 

Family II. — Octopodid^. 

Arms similar, elongated, united at the base by a web. Shell 
represented by two short styles, encysted in the substance of 
the mantle. (Owen.) 

Octopus, Cuvier. Poulpe. 

Etymology, odo, eight, pous {poda), feet. 

Synonyms, cist opus. (Gray.) 

Example, 0. tuberculatus, BL, PI. I., Figs. 1 and 2 (man 
dibles). 

Body oval, warty or cirrose, without fins ; arms long, un- 
equal ; suckers in two rows ; mantle supported in front by the 
branchial septum. 

The octopods are the "polypi" of Homer and Aristotle; 
they are solitary animals, frequenting rocky shores, and are 
very active and voracious ; the females oviposit on sea-weeds, 
or in the cavities of empty shells. In the markets of Smyrna 
and Naples, and the bazaars of India, they are regularly ex- 
posed for sale. " Although common (at St. Jago) in the pools 
of water left by the retiring tide, they are not very easily caught. 
By means of their long arms and suckers they can drag their 
bodies into very narrow crevices, and when thus fixed it re- 



164 



MAlfUAL OF THE MJLLUSCA, 



quires great force to remove them. At other tim.es they dart 
tail first, with the rapidity of an arrow, from one side of the 
pool to the other, at the same instant discolouring the water 
with a dark chesnut-brown ink. They also escape detection 
by varying their tints, according to the nature of the ground 

over which they pass. In the 
dark they are slightly phospho- 
rescent." (Darwin.)* Professor 
E. Forbes has observed that 
the octopus, when resting, coils 
its ventral arms over its back, 
and seems to shadow forth the 
argonaut's shell. 

In the male octopus, the third 
right arm is more developed than 
the corresponding arm on the 
left side, and terminates in an 
oval-shaped plate (Fig. 38, c), 
marked with numerous trans- 
verse ridges, between which are 
pits. A muscular fold of skin 
passes from this plate down the 
dorsal margin of the arm to 
the web at its base ; the mar- 
gin is rolled up, and forms a 
covered passage through which 
the spermatophore is probably 
transmitted to the terminal plate. 
The arm is permanently at- 
tached, and is developed in a 
free state from a cyst, A. 

Distribution : universally 
found on the coasts of the tem- 
perate and tropical zones; 46 
species are known ; when 
adult they vary in length from 
1 inch to more than 2 feet, according to the species. 




Fig. 38. Octopus carena $ , Ver. 

A, Side view, showing cyst in place of 
third arm. 

B, Ventral side of an individual more 
developed, with the Hectocotylus C. 



Suh-genus. Tremodopus (Ohiaje), PL I., Pig. 3. 

Name from two large aquiferous pores [tremata) on the back 
of the head. 

* "Journal of a Voyage round the World." The most fascinating volume of 
travels published since Defoe's fiction. 



CEPHALOPODA. 16/5 

Arms longer than the body ; the two dorsal pairs the longest, 
and webbed half-way up, and sometimes to the extremities. 
Arms not webbed in male. 4 aquiferous (?) openings, two be- 
tween the eyes, and two below ; sometimes there are small 
openings on the sides ; suckers in two rows ; third right arm 
hectocotylised. 

Distribution, 3 species. T. quoyanus, violaceus, and velifer. 
Atlantic and Mediterranean. 

PiisnsrocTOPiTs, D'Orb. Finned octopus. 

Body with lateral fins, united behind. 

The only known species, P. cordiformis, was discovered by 
MM. Quoy and Gaimard, on the coast of New Zealand; it 
exceeds 3 feet in length 

Eledone. (Aristotle.) Leach. 

Type, E. octopodia, L. 

Suckers forming a single series on each arm ; length 6 to 18 
inches. E. Moschata emits a musky smell. Third right arm 
hectocotylised ; permanently attached ; developed free. 

Distribution, 2 species. Coasts of Norway, Britain, and the 
Mediterranean. 

CiRHOTEUTnis. Eschricht. 1836. 

Synonyms^ Sciadephorus (Eeinh and Prosch) ; Bostrycho- 
teuthis (Ag.) 

Etymology, cirrus, a filament, and teuthis, a cuttle-fish. 

Body with two transverse fins ; arms united by a web, nearly 
to their tips ; suckers in a single row, alternating with cirri. 
Length 10 inches. Colour violet. The only species ((7. Miillerij 
Esch.) inhabits the coast of Greenland. 

Philonexis, D'Orb. 

Etymology, pliilos, an adept in nexis, swimming. 

Type, P. atlanticus, D'Orb. 

Arms free ; suckers in two rows ; mantle supported by two 
ridges on the funnel ; eyes large and prominent. Total length, 
1 to 3 inches. 

Distribution, 6 species. Atlantic and Mediterranean. Gre- 
garious in the open sea ; feeding on floating mollusca. 

Sc^TJKGTJS. Troschel. 1857. 
Body oval, without fins ; wider than the head ; ann& ghort ; 



166 



MANUAL OP THE MOLLTTSCA. 



suckers in two rows; tlie tliird left arm nectocotylised at tlie 
apex. 
Diatrihution, 2 species. Mediterranean. 

BoLiT^NA. Strp. 1858. 

Similar to Eledone, but more gelatinous, and with small 
suckers. 1 species Hying. 

Section B. — Decapoda. 

Arms 8. Tentacles 2, elongated, cylindrical, with expanded 
ends. Suckers pedunculated, armed with a horny ring. Mouth 
surrounded by a buccal membrane, sometimes lobed and fur- 
nished with suckers. Eyes movable in their orbits. Body 
oblong or elongated, always provided with a pair of fins. Funnel 
usually furnished with an internal valve. Oviduct single. Nida- 
mentcd gland largely developed. Shell internal ; lodged loosely 
in the middle of the dorsal aspect of the mantle. 

The arms of the decapods are comparatively shorter than 
those of the octopods ; the dorsal pair is usually shortest, the 
ventral longest. The tentacles originate within the circle of 
the arms, between the third and fourth pairs ; they are usually 
much longer than the arms, and in cheiroteuthis are six times 
as long as the animal itself. They are completely retractile 
into large subocular pouches in sepia, sepiola, and rossia ; partly 
retractile in loligo and sepioteuthis ; non-retractile in cheiroteuthis. 
They serve to seize prey which may be beyond the reach of the 
ordinary arms, or to moor the animal in safety during the 
agitation of a stormy sea. 

The lingual dentition of the cuttle-fishes somewhat resembles 
that of the ptercooda. The central teeth are simple in sepia and 




Fig. 39. Lingual teeth of Sepia officinalis (Cockeii). 

sepiola^ tricuspid in loligo, and denticulated in eledone. The 
lateral teeth or uncini are three on each side, and mostly simple 
and claw-like. There were fifty rows of teeth in one specimen 
of sepm, the ribbon increasing in breadth from before to behind. 



CErHALOPODA. 167 

' The shell of the living decapods is either a horny ''pen" 
.[gladius) or a calcareous "bone" [sepion) ; not attached to tho 
animal by muscles, but so loose as to fall out when the cyst 
which contains it is opened. In the genus spirula it is a delicate 
spiral tube divided into air-chambers by partitions [sejpta). In 
the fossil genus sjoiruUrostra a similar shell forms the apex of 
a cuttle-bone ; in the fossil conoteuthis a chambered shell is 
combined with a pen; and the helemnite unites all these 
modifications. 

The decapods chiefly frequent the open sea, appearing periodi- 
cally like fishes, in great shoals, on the coasts and banks. (Owen, 
D'Orbigny.) 

Pamily III. — Teijthid^. Calamabies, or Squids. 

Body elongated ; fins short, broad, and mostly terminal. 

Shell (gladius ox pen) horny, consisting of three parts, — a shaft, 
and two lateral expansions or wings. 

Sub -family A. Myopsidce, D'Orbigny. Eyes covered by the 
skin. 

LoLlGO. {Pliny) Lamarck. Calamary. 

Synonym, teuthis (Aristotle), Gray. 

Type, L. vulgaris (sepia loligo, L.). Fig. 1. PI. I., fig. 6 

Pen lanceolate, with the shaft produced in front ; it is multi- 
plied by age, several being found packed closely, one behind 
another, in old specimens. (Owen.) 

Body tapering behind, much elongated in the males. Fins 
terminal, united, rhombic. Mantle supported by a cervical 
ridge, and by two grooves in the base of the funnel. Suckers in 
two rows, with horny, dentated hoops. Tentacular club with 
four rows of suckers. Length (excluding tentacles) from 3 
inches to 2f feet. Fourth left arm in male metamorphosed at 
its extremity. Steenstrup* says two species are confounded 
under the name of L. vulgaris. The variety occurring in the 
Atlantic, and not in the Mediterranean, is a distinct species {L. 
Forhesii, Stp.). In it the fourth left arm has twenty-three pairs 
of suckers well developed, five less developed, while the arm 
beyond the twenty-eighth pair is occupied by forty pairs of 
conical elongated papillae, which correspond to forty pairs of 
suckers.. Steenstrup recognises only seven living species of 
Loligo, all the others so called being only varieties of these. 

* Annals of Natural History, 1S57. 



168 MANUAL OF THE MOLLUSC A. 

The calamaries are good swimmers; they also crawl, head, 
downwards, on their oral disk. The common species is used for 
bait, by fishermen, on the Cornish coast. (Couch.) Shells have 
been found in its stomach, and more rarely sea-weed. (Dr. 
Johnston.) Their egg-clusters have been estimated to contain 
nearly 40,000 eggs. (Bohadsch.) 

Distribution, 24 species, in all seas. Norway — New Zealand. 

Fossil, 1 species. Lias. 

Suh-genus. Teudopsis, Deslongchamps, 1835. 
Etymology, teuthis, a calamary, and opsis, like. 
Type, T. Bunellii, Desl. 

Pen like loligo, but dilated and spatulate behind. 
i^oss*7, 5 species. Upper Lias, Oolite; France and Wurtemberg. 

GrONATUS, Gray. 

Animal and pen like loligo in most respects. Arms with four 
series of cups ; tentacular duh with numerous small cups, and a 
single large sessile cup armed with a hook; funnel valveless. 

Distribution, a single species {G. amcena, Miiller sp.) is found 
on the coast of Greenland. 

Sepiotetjthis, Blainville. 

Synonyms, (?) Loliolus (Steenstrup) ; Chondrosepia (Leuckart). 

Type, S. sepioidea, Bl. Animal like loligo ; fins lateral, as 
long as the body. Length from 4 inches to 3 feet. Fourth left 
arm hectocotylised at the apex. 

Distribution, 13 species. West Indies, Cape, Eed Sea, Java, 
Australia, Mediterranean. 

Belotetjthis, Miinster. 

Etymology, belos, a dart, and teuthis. 

Type, B. subcostata, Miinster. PI. II., fig. 8., Upper Lias, 
"Wurtemberg. 

Pen horny, lanceolate ; with a very broad shaft, pointed at 
each end, and small lateral wings. 

Distribution, 6 species described by Miinster, considered 
varieties of one only (differing in age and sex) by M. D'Orbigny . 

Geoteuthis, Miinster. 

Etymology, ge, the earth [i. e. fossil), and teuthis. 
Synonyms, belemnosepia (Agassiz), belopeltis (Yoltz), loligo - 
sepia (Quenstedt), Coccoteuthis, Owen (part) 
Type, Loligo Aalensis (Schubler). 



CEPHALOPODA. 169 

Pen broad, pointed behind ; shaft broad, truncated in front ; 
lateral wings shorter thau the shaft. 

Fossil, 9 species. Upper Lias, Wurtemberg ; Calvados ; 
Lyme Eegis. Several undescribed species in the Oxford clay, 
Chippenham. 

Besides ih.Q pens of this calamary, the inJc-hag, the muscular 
mantle, and the bases of the arms, are preserved in the Oxford 
clay. Some of the ink-bags found in the Lias are nearly a foot 
in length, and. are invested with a brilliant nacreous layer ; the 
ink forms excellent sepia. It is difficult to understand how 
these were preserved, as the recent calamaries " spill their ink" 
on the slightest alarm. (Buckland.) This genus may probably 
turn out to belong to the Belemnitidse. 

Leptotetjthis, Meyer. 

Etymology, Lepfos, thin, and teuthis. 
Type, L. gigas, Meyer, Oxford clay, Solenhofen. 
Pen very broad and rounded in front, pointed behind ; with 
obscure diverging ribs. 

Cea]S"Chia, Leach, 1817. 

Named in honour of Mr. J. Cranch, naturalist to the Congo 
expedition. 

Synonym, Owenia, Prosch. 

Type, C. scabra, Leach. 

Body large, ventricose ; fins small, terminal ; mantle supported 
in front by a branchial septum. Length two inches. Head very 
small. JEyes fixed. Buccal membrane large, 8-lobed. Arms 
short, suckers in two rows. Tentacular clubs finned behind, 
cups in four rows. Funnel valved. 

Pen long and narrow. 

Pistrihution, 3 species. "West Africa ; in the open sea. 

This genus makes the nearest approach to the octopods. 

Sepiola. (Eondelet) Leach, 1817. 

Example, S. atlantica (D'Orbigny). PL I., fig. 4. 

Body short, purse-like ; mantle supported by a broad cervical 
band, and a ridge fitting a groove in the funnel. Fins dorsal, 
rounded, contracted at the base. Suckers in two rows, or 
crowded, on the arms, in four rows on the tentacles. Length 
two to four inches. First left arm hectocotylised. 

Pen half as long as the back. S. Stenodactyla (sepioioidea, 
D'Orbigny) has no pen. 



170 MANUAL OP THE MOLLUSCA. 

Distribution, 1 species. Coasts of Norway, Britain, Mediter- 
ranean, Mauritius, Japan, Australia. 

Sub-genus. Bossia, Owen (R. palpebrosa). Synonym, Hetero- 
teuthis (Gray). Mantle, supported by a cervical ridge and 
groove. Suckers in two rows on tlie tentacles. First left arm 
hectocotylized throughout its length, and the corresponding 
right one in the middle. Length three to five inches. . 

Distribution, 6 species. Eegent Inlet, Britain, Mediterranean, 
Manilla. 

Sub -family B. Oigopsidoe, D'Orbigny. 

Eyes naked. Fins always terminal, and united, forming a 
rhomb. 

LoLiGOPSis, Lam. 1812. 

Etymology, loligo, and opsis, like. 

Synonyms, JjQdiOkidt., Les., 1821; Perotis, Eschscholtz, 1827; 
Taonius, Steenstrup, 1861. 

Tyjpe, L. pavo (Lesueur). 

Body elongated, mantle supported in front by a branchial 
septum. Arms short. Cups in two rows. Tentacles slender, 
often mutilated. Funnel valveless. 

Fen slender, with a minute conical appendix. Length from 
six to twelve inches. 

Distribution, pelagic, 8 species. North Sea, Atlantic, Medi- 
terranean, India, Japan, South Sea. 

Cheiroteuthis, D'Orbigny. 

Etymology, cheir, the hand, and teuthis. 

Type, 0. veranii, Per. 

ilfaTz^Ze supported in front by ridges. Funnel YalvBless. Ven- 
tral arms very long. Tentacles extremely elongated, slender, 
with distant sessile cups on the peduncles, and four rows of 
pedunculated claws on their expanded ends. 

Pen slender, slightly winged at each end. Length of the body 
two inches ; to the tips of the arms eight inches ; to the ends of 
the tentacles three feet. 

Distribution, 2 species. Atlantic, Mediterranean ; on gulf- 
weed in the open sea. 

HiSTiOTETjTHis, D'Orbigny. 

'Etymology, hisfion, a veil, and teuthis. 

Vype, H. bonelliana, Fer. Length 16 inches. 

Jiody short. Fins terminal, rounded. Mantle supported in 



CEPHALOPODA. 171 

front by ridges and grooves. Buccal membrane 6-lobed. Arms 
(except the ventral pair) webbed high up. Tentacles long, out- 
side the web, with six rows of dentated cups on their ends. 

Pen short and broad. 

Distribution, 2 species. Mediterranean ; in the open sea. 

Onychoteuthis, Lichtenstein. Uncinated calamary. 

Etymology, onyx, a claw, and teuthis. 

Type, 0. banksii, Leach ( — bartlingii ?). PI. I., fig. 7 and 
fig. 8 {pen). 

Synonyms, ancistroteuthis (Grray). Onychia (Lesueur). 

Fen narrow, with hollow, conical apex. 

Arms with two rows of suckers. Tentacles long and powerful, 
armed with a double series of hooks; and usually having a 
small group of suckers at the base of each club, which they are 
supposed to unite, and thus use their tentacles in conjunction.* 
Length four inches to two feet. 

The uncinated calamaries are solitary animals, frequenting 
the open sea, and especially the banks of gulf- weed {sargasso). 
0. hanksii ranges from Norway to the Cape and Indian ■ Ocean ; 
the rest are confined to warm seas. 0. dussumieri has been taken 
swimming in the open sea, 200 leagues north of the Mauritius. 

Distribution, 8 species. Atlantic, Indian Ocean, Pacific. 

Enoplotetjthis, D'Orbigny. Armed calamary. 

Etymology, enoplos, armed, and teuthis. 

Type, E. smithii, Leach. 

Synonyms, ancistrochirus and abralia (Gray), octopodoteuthis 
(Euppell), verania (Krohn). 

Pen lanceolate. Arms provided with a double series of horny 
hooks, concealed by retractile webs. Tentacles long and feeble, 
with small hooks at the end. Length (excluding the tentacles) 
from two inches to one foot ; but some species attain a largei 
size. In the-museum of the College of Surgeons there is an 
arm of the specimen of E. unguiculata, found by Banks and 
Solander in Cook's first voyage (mentioned at p. 158), sup- 
posed to have been 6 feet long when perfect. The natives of 
the Polynesian Islands, who dive for shell-fish, have a well- , 
founded dread of these formidable creatures. (Owen.) 

Distribution, 10 species. Mediterranean, Pacific. 

Fossil, 1 species. Oolite. 

» The obstetric forceps of Professor Simpson were suggested by the suckers of the 
calamarj'. 

12 



172 MANUAL OF THE MOLLUSCA. 

Ommastrephes, D'Orbigny. Sagittated calamary. 

Etymology^ omma, the eyes, and strepho, to turn. 

Synonym, Hyaloteutliis (Grray). 

Type, O. sagittatus, Lam. 

Body cylindrical ; terminal fins large and rliombic. Arms 
■with two rows of suckers, and sometimes an internal mem- 
branous fringe. Tentacles sbort and strong, with four rows of 
cups. 

Pen consisting of a sbaft with, three diverging ribs, and a 
hollow conical appendix. Length, from one inch to nearly four 
feet. 

The sagittated calamaries are gregarious, and frequent the 
open sea in all climates. They are extensively used in the cod- 
fishery oflf Newfoundland, and are th.e principal food of the 
dolphins and cachalots, as well as of the albatross and larger 
petrels. The sailors call them " sea-arrows," or "flying squids," 
from their habit of leaping out of the water, often to such a 
height as to fall on the decks of vessels. They leave their eggs 
in long clusters floating at the surface. 

Distribution, 14 recent species ; similar pens (4 species) have 
been found fossil in the Oxford clay, Solenhofen ; it may, how- 
ever, be doubted whether they are generically identical. There 
is 1 tertiary species. 

Thysanoteuthis, Troschel. ' 1857. 

Etymology, thysanos, a fringe. 

Arms sessile and webbed, but without hooks. Tentacles fur- 
nished with cups. Fin long. Pen sagittate. Two recent 
species, T. rhombus, T. elegans. Mediterranean. 

LoLiOLUS, Stp. 1856. 

Pen horny, broad, with the shaft sharp-keeled ; no muscular 
bands to the funnel ; suckers with a raised band. Left fourth 
arm hectocotylised. *''; 

Distribution, 2 species. Indian Ocean. , 

Plesioteuthis, Wagner. 1860. 

Pen slender, with a central and two side ridges. Point 
arrow-shaped. Arms with hooks. 

Distribution, 2 species. Lias. Solenhofen slate. 



CEPHALOPODA. 173 

DOSIDICTJS, Stp. 1856. 

Somewhat like Ommastrephes. Lower portion of arms with 
large suckers, and the extremity with numerous small suckers. 
Tentacles with four or fiye hooks. 

Distribution, 1 species. Mediterranean. , 

Family IY. — ^BELEMisriTiDiE. 

Shell consisting of a jpen, terminating posteriorly in a cham- 
bered cone, sometimes invested with a fibrous guard. The air- 
cells of the phragmocone are connected by a siphunde, close to 
the ventral side. 

Belemkites, Lamarck. 1801. ' 

Etymology, helemnon, a dart.* 

Example, B. puzosianus, PL II., Fig. 5. 

Phragmocone horny, slightly nacreous, with a minute globular 
nucleus at its apex ; divided internally by numerous concave 
septa. Pen represented by two nacreous bands on the dorsal 
side of the phragmocone, and produced beyond its rim, in the 
form of sword-shaped processes (PL II., Pig. o).-j- Guard 
fibrous, often elongated and cylind] ical ; becoming very thin in 
front, where it invests the phragmocone. J Suckers provided 
with horny hooks. 

More than 100 species of belemnites have been found in a 
fossil state, ranging from the lias to the chalk, and distributed 
over all Europe. A few species have been found in the chalk 

* The termination ites (from lithos, a stone) was formerly given to all fossil genera. 

t Eive specimens -w^er.e at one time in Dr. Mantell's cabinet, and others are in the 
British Museum ; they were obtained by William Buy in the Oxford clay of Christian 
Malford, Wilts. A still finer specimen, in Mr. Montefiore's collection, was recently 
obtained from the has of Dorsetshire by Mr. Day. The last chamber of a lias 
belemnite in the British Museum is 6 inches long, and 2| inches across at the smaller 
end ; a fracture near the siphuncle shows the ink-hag. The phragmocone of a specimen 
corresponding to this in size measures 7f inches in length, 

X The specific gravity of the guard is identical with that of the sheU of the recent 
pinna, and its structure is the same. Parkinson and others have supposed that it was 
originally a light and porous structure, like the cuttle bone ; but the mucro of the 
sepiostaire, with which alone it is homologous, is quite as dense as the belemnite. We 
are indebted to Mr. Alex. Williams, M.R.C.S., for the following specific gravities of 
recent and fossil shells, compared with water as 1,000 : — 

Belemnites puzosianus, Oxford clay 2,674 



Belemnitella mucronata, chalk 

Pinna, recent, from the Mediterranean 
Trichites plottii, from the inferior oolite 

Conus monile, recent 

Conus ponderosus, Miocene, Touraine ... 



2,677 
2,607 
2,670 
2,010 
2,713 



174 MANUAL OF THE MOLLUSC A. 

of Southern India, and a few more in the Jurassic formation of 
the Himalayas. The phragmocone of the belemnite, which re- 
presents the terminal appendix of the calamaries, is divided into 
air-chambers, connected by a small tube {siphuncle), like the 
shell of the pearly nautilus. It is exceedingly delicate, and 
usually owes its preservation to the infiltration of calcareous 
spar : specimens frequently occur in the lias, with the meniscus- 
shaped casts of the air-chambers loose, like a pile of watch- 
glasses. It is usually eccentric, its apex being nearest to the 
ventral side of the guard. The guard is very variable in its 
j)roportions, being sometimes only half an inch longer than the 
phragmocone, at others one or two feet in length. These 
variations probably depend to some extent on age and sex ; 
M. D'Orbigny believes that the shells of the males are always 
(comparatively) long and slender ; those of the females are at 
first short, but afterwards growing only at the points, they 
become as long in proportion as the others. The guard always 
exhibits (internally) concentric lines of growth ; in B. irregularis 
its apex is hollow. Our knowledge of this genus now extends 
to the form and proportions of the body, arms, the hooks, ink- 
bag, one type of pro-ostracum and beak. The belemnites have 
been divided into groups by the presence and position of furrows 
on the surface of the guard. 

Section I. Acceli (Bronn.), without dorsal or ventral grooves. 

Sub-section 1. Acuarii, without lateral furrows, but often 
channelled at the extreme point. 

Type, B. acuarius. 20 species. Lias — Neocomian. 
Sub-section 2. Clavati, with lateral furrows. 
Type, B. clavatus. 3 species. Lias. 

Section II. Gastrocosli (D'Orb.), ventral groove distinct. 

Sub-section 1. Oanaliculati, no lateral furrows. 
Type, B. canaliculatus. 5 species. Inferior oolite — Great 
oolite. 

Sub-section 2. Hastati, lateral furrows distinct. 
Type, B. hastatus. 19 species. Upper lias — Gault. 

Section III. Notocgeli (D'Orb.), with a dorsal groove, 
and furrowed on each side. 

Type, B. dilatatus. 9 species. Neocomian. 
The belemnites appear to have been gregarious, from the 
exceeding abundance of their remains in many localities, as in 



CEPHALOPODA. 175 

Fome of tlie marlstone quarries of the central counties, and the 
lias cliffs of Dorsetshire. It is also probable that they lived in 
a moderate depth of water, and preferred a muddy bottom to 
rocks or coral-reefs, with which they would be apt to come in 
perilous collision. Belemnites injured in the lifetime of the 
animal have been frequently noticed. 

Belemnitella, D'Orb. 

Synonym, Actinocamax, Miller (founded on a mistake.) 

Type, B. mucronata, Sby. PI. II., Fig. 6. 

Distribution, Europe; North America. 6 species. Upper 
greensand and chalk. 

The guard of the belemnitella has a straight fissure on the 
ventral side of its alveolar border ; its surface exhibits distinct 
vascular impressions. The phragmocone is never preserved, but 
casts of the alveolus show that it was chambered, that it had 
a single dorsal ridge, a ventral process passing into the fissure 
of the guard, and an apical nucleus. 

XiPHOTEUTHIS, Hux. (1864). 

Shell with a long phragmocone enveloped in a calcareous 
sheath. 

Fossil. 1 species. Lias. England. 

AcAiS'THOTEUTHis (Wagner), Miinster. 

Etymology, acantha, a spine, and teuthis. 

Synonyms, Kalseno (Miinster). Belemnoteuthis ? 

Type, A. prisca, Euppell. 

Eounded on the fossil hooks of a calamary, preserved in the 
Oxford clay of Solenhofen. These show that the animal had 
ten nearly equal arms, all furnished with a double series of 
horny claws, throughout their length. A pen like that of the 
ommastrephes has been hypothetically ascribed to these arms, 
which may, however, have belonged to the lelemnite or the 
belemnoteuthis. 

Fossil. 17 species. Oolite. 

Belemnoteuthis (Miller, Pearce, 1842). 

Type, B. antiquus (Cunnington), Fig. 40. 

Shell consisting of a phragmocone, like that of the belemnite ; 
a horny dorsal pen with obscure lateral bands ; and a thin 
fibrous guard, with two diverging ridges on the dorsal side. 



176 



MANUAL OF THE MOLLUSCA. 



Animal proyided with arms and tentacles of nearly equal 

length, furnished with a double 
alternating series of horny hooks, 
from 20 to 40 pairs on each arm ; 
mantle free all round; Jins large, 
medio-dorsal (much larger than in 
Fig. 40). 

Fossil in the Oxford clay of 
Chippenham. Similar horny claws 
have been found in the lias of 
K gliflK Watchett, and a guard equally thin 

(^ ^ -^J ^ is figured in Buckland's Bridge- 

water Treatise, t. 44, Eig. 14. 

In the fossil calamary of Chip- 
penham the shell is preserved along 
with the muscular mantle, fins, 
ink-bag, funnel, eyes, and tentacles 
with their horny hooks. All the 
specimens were discovered, and de- 
veloped with unexampled skill, by 
William Buy, of Sutton, near Chip- 
penham. 

COI^OTEUTHIS, D'Orb. 

Type, C. Dupinianus, D'Orb. 
_. _ , PL II., Pig. 9. Neocomian.Yxance: 

T^. 40. Belemnoteuthzs* ^^^^^ England. 

Phragmocone slightly curved. Pen elongated, very slender. 

This shell, which is like the pen of an ommastrephe, with a 
chambered cone, connects the ordinary calamaries with the 
belemnites. 

Pamilt Y. — Sepiad^. 

Shell (cuttle-bone, or sepiostaire) calcareous ; consisting of a 
broad laminated plate, terminating behind in a hollow, imper- 




* Eig. 40. Belemnoteuthis antiquus, f, ventral side, from a specimen in the cabinet 
of William Cunnington, Esq., of Devizes. The last chamber of the phragmocone is 
preserved in this specimen, a, represents the dorsal side of an uncompressed phrag- 
mocone from the KeUoway rock, in the cabinet of J. G-. Lowe, Esq. ; c, is an ideal 
section of the same. Since this woodcut was executed a more complete specimen has 
been obtained for the British Museum ; the tentacles are not longer than the ordinary 
arms, owing, perhaps, to theu- partial retraction ; this specimen is figured in Dr. 
Mantell's " Petrifactions and their Teachings." d, is a single hook, natural size. The 
epecimens belonging to Mr. Cunnington and the late Mr. C. Pearce show the larg© 
acetabular bases of the hooks. 



CEPHALOPODA. 177 

fectly ckambered apex {mucro). Animal with elongated ten- 
tacles, expanded at their ends. 

Sepia (Pliny), Linnaeus. 

Type, S. officinalis, L. PI. I., Pig. 5. 

Synonyms, Bdosepia, Yoltz. (B. sepioldea, PI. II., Pig. 3, 
inucro only.) Palseoteuthis, Eoem. 

Body oblong, with lateral fins as long as itself. Arms with 
four rows of suckers. Mantle supported by tubercles fitting into 
sockets on the neck and funnel. Length 3 to 28 inches. 

Shell as wide and long as the body; very thick in front, 
concave internally behind ; terminating in a prominent mucro. 
The thickened part is composed of numerous plates, separated 
by vertical fibres, which render it very light aiid porous. S. 
Orbignyana, PI. XL, Pig. 2. 

The cuttle-bone was formerly employed q,s an antacid by 
apothecaries; it is now only used as "pounce," or in casting 
counterfeits. The bone of a Chinese species attains the length 
of 1-| foot. (Adams.) 

The cuttle-fishes live near shore, and the mucro of their shell 
seems intended to protect them in the frequent collisions they 
are exposed to in swimming backwards. (D'Orbigny.) 

Distribution, 30 species. World-wide ; 2 British. 

Fossil, 10 species. Oxford clay, Solenhofen. Several species 
have been founded on mucrones from the Eocene of London and 
Paris. PI. II., Fig. 3. S. ungula occurs fossil in Texas. 

SpiRTrLinosTEA, B'Orb. 

Type, S. Bellardii (D'Orb.). PL IL, Pig. 4. Miocene, 
Turin. 

Shell, mucro only known ; chambered internally ; chambers 
connected by a ventral siphuncle ; external spathose layer pro- 
duced beyond the phragmocone into a long pointed beak. 

Belopteha (Blainville), Deshayes. 

Etymology, helos, a dart, and pteron, a wing. 
Type, B. belemnitoides, Blainville. PL IL, Pig. 7? 
Shell, mucro (only known) chambered and siphuncled j winged 
externally. 

Fossil, 4 species. Eocene. Paris ; Brackleshani. 

Belemkosis, Edwards. 

Type, B. anomalus, Sby. species. Eocene. Highgate (unique). 

i3 



178 MANTTAL OF THE MOLLUSCA. 

- Shell, mucro chambered and siphuncled ; without lateral wings 
or elongated beak. 

Helicerijs, Dana. 

Example, H. Fugiensis. Only species known. 

Shell like a belemnite, balf-incli in diameter ; guard thick, 
sub-cylindrical, fibrous ; phragmocone slender, terminating in a 
fusiform spiral nucleus. In slate rock, Cape Horn. 

Family VI. — Spirulid^. 

Shell entirely nacreous ; discoidal ; whorls separate, chambered 
.{polythalamous), with a ventral siphuncle. 

Spirtjla, Lam., 1801. 

Synonym, Lituus, Gray. 

Example, S. Isevis (Gray). PI. I., Fig. 9. 

Body oblong, with minute terminal fins. Mantle supported 
by a cervical and two ventral ridges and grooves. Arms with 
six rows of very minute cups. Tentacles elongated. Funnel 
Valved. 

Shell placed vertically in the posterior part of the body, with 
the involute spire towards the ventral side. The last chamber 
is not larger in proportion than the rest ; its margin is organically 
connected ; it contains the ink-bag. 

The delicate shell of the spirula is scattered by thousands on 
the shores of New Zealand ; it abounds on the Atlantic coasts, 
and a few specimens are yearly brought by the Gulf-stream, 
and strewed upon the shores of Devon and Cornwall. But the 
animal is only known by a few fragments, and one perfect 
specimen, obtained by Mr. Percy Earl on the coast of New 
Zealand. 

Distribution, 3 species. All the warmer seas. 

Ordeii II. — Teteabrai^chiata. 

Animal creeping ; protected by an external shell. 

Head retractile within the mantle. Eyes pedunculated. Man- 
dibles calcareous. Arms very numerous. Body attached to the 
shell by adductor muscles, and by a continuous horny girdle. 
Branchiae, four. Funnel formed by the union of two lobes, which 
do not form a complete tube. 

Shell external, camerated (polythalamous) and siphuncled ; the 
inner layers and septa nacreous ; outer layers porcellanous.* 

* Tlie Chinese carve a variety of patterns in the outer opaque layer of the nautilus 
shell, relieved by the pearly ground beneath. 



CEPHALOPODA. 



179 



It was long ago remarked by Dillwyn, tliat shells of the car- 
nivorous gasteropods were almost, or altogether, wanting in the 
jjalseozoic and secondary strata; and that the office of these 
animals appeared to have been performed, in the ancient seas, 
by an order of cephalopods, now nearly extinct. Above 2,000 
fossil species belonging to this order are now known by their 
shells ; whilst their only living representatives are a few species 
of nautili.* 

The shell of the tetrabranchiate cephalopods is an extremely 
elongated cone, and is either straight, or variously folded, or 
coiled. 



It is straight in . 
hent on itself in 
curved in . . . 
spiral in . . . 
discoidal in . 
discoidal and produced in 
involute in . 



orthoceras 

ascoceras 

cyrtoceras 

trochoceras 

gyroceras 

litilites 

nautilus 



baculites. 

ptychoceras. 

toxoceras. 

turrilites. 

crioceras. 

ancyloceras. 

ammonites. 



Internally, the shell is divided into cells or chambers, by a 
series of partitions [septa), connected by a tube or sipTiuncle. The 
last chamber only is occupied by the animal. The others are 




Fig. 41. Suture of an ammonite.t 

probably occupied in succession. They are empty during life, 
but in fossil specimens they are often filled with spar. When 
the outer shell is removed (as often happens to fossils), the edges 
of the septa are seen (as in PL III., Figs, 1,2). Sometimes they 
form curved lines, as in nautilus and orthoceras, or they are 
zigzag, as ingoniatites (Fig. 60), or foliaceous, as in the ammonite 
(Fig. 41). 

* The frontispiece^ copied from Professor Owen's Memoir, represents the animal of 
the first nautilus, captured off the New Hebrides, and brought to England by Mr. 
Bennett ; it is drawn as if lying in tlie section of a shell, without concealing any part 
of it. The woodcut. Fig. 50, is taken from a more perfect specimen, stibsequently 
acquired by the British Museum, in which the relation of the animal to its shell is 
accurately shown. 

t A. heterophi/Hus, Sby., from the lias, LjTiie Eegis. British Museum. Only one 
side is represented ; the aixow indicates the dorsal saddle. 



180 MAmiAl, OP THE MOILTTSCA. 

The outlines of the septa are termed sutures ;* when they are 
folded the elevations are called saddles, and the intervening de- 
pressions lohes. In ceratites (Fig. 61) the saddles are round, the 
lobes dentated ; in ammonites both lobes and saddles are extremely 
complicated. Broken fossils show that the septa are nearly flat 
in the middle, and folded round the edge (like a shirt-frill), 
where they abut against the outer shell- wall (Fig. 44). 

The siphunde of the recent nautilus is a membranous tube, 
with a very thin nacreous investment ; in most of the fossils it 
consists of a succession of funnel-shaped, or bead-like tubes. 
In some of the oldest fossil genera, actinoceras, gyroceraa, and 
phragmoceras, the siphuncle is large, and contains in its centre a 
smaller tube, the space between the two being filled up with 
radiating plates, like the lamellae of a coral. Thje position of the 
siphuncle is very variable ; in the arnmonitidce it is external, or 
close to the outer margin of the shell (Fig. 44). In the nautilidm 
it is usually central (Fig. 42), or internal (Fig. 43). 





Fig, 42. Nautilus. Fig. 43. CljTnenia. Fig. 44. Hamites.t 

The air-chamhers of the recent nautilus are lined by a very 
thin, living membrane; those of the fossil orthocerata retain 
indications of a thick vascular lining, connected with the animal 
by spaces between the beads of the siphuncle. J 

The hody-chamher is always very capacious ; in the recent 
nautilus its cavity is twice as large as the whole series of air- 
cells ; in the goniatite (Fig. 46) it occupies a whole whorl, and 
has a considerable lateral extension ; and in ammonites comonunia 
it occupies more than a whorl. 

The margin of the aperture is quite simple in the recent nautilus, 

* From their resemblance to the sutures of the skull. 

t Fig 42. Nautilus Pompilius, L. Fig. 43. Clymenia striata, Miinst,, see PI. II-, 
Fig. 16. Fig. 44. Hamites cylindraceus, Defr., see Fig. 65. 

X JMost of the so-called spongaria are detached septa of an orthoceras, from the 
Upper Ludlow rock, in which the vascular markings distinctly radiate from the 
siphuncle. Mr. Jones, Warden of Clun Hospital, has several of these in apposition. 



CEPSAlOfODA. 



181 



and affords no clue to the many curious modifications observable 
in tiie fossil forms. In the ammonites we frequently find a dorsal 




Fig. 45. Ammonites. Fig. 46. Goniatites.* 

process, or lateral projections, developed periodically, or only in 
the adult (Eig. 62, and PI. III., Eig. 5). 

In phragmoceras and gomphoceras (Figs. 47, 48) the apeyture is 
BO much contracted that it is obvious the animal could not have 
withdrawn its head into the shell like the nautilus. 





Fig. 47. Gomphoceras Fig. 48. Phragmoceras. t 

M. Barrande, from whose great work on the Silurian Forma- 
tions of Bohemia these figures are taken, suggests that the lower 
part of the aperture (s s), which is almost isolated, may have 

* Fig. 45. Section of Ammonites ohtusus^ Sby. lias, LjTne Regis ; from a very yoting 
specimen. Fig. 46. Section of goniatites sphcericust Sby. carb. limestone, Bolland (in 
the cabinet of Mr. Tennant). The dotted Mnes indicate the lateral extent of the 
body-chamber. 

t Fig. 47. Gomphoceras Bohemicum (Barrande), reduced view of the aperture ; s, 
the siphonal opening. Fig. 48. Phragmoceras callistoma (Barr.), both from the U. 
Silurian, Bohemia. 



182 



MAirtJAL OF THE MOLLUSCA. 




Berved for the passage of the fannel, wHlst the tipper and larger 
space (c c) was occupied by the neck ; the lobes probably indicate 
the position of the external arms. 

The aperture of the pearly nautilus is closed by a disk or hood 
(Fig. 50, h), formed by the union of the two dorsal arms, which 
correspond to the shell-secreting, arms of the argonaut. 

In the extinct aTnmonites we have eyidence that the aperture 
was guarded still more ejffectively by a horny or shelly operculum, 
secreted, in all probability, by these dorsal arms. In one group 
{arietes), the operculum consists of a single 
piece, and is horny and flexible.* In the 
round-backed ammonites the operculum is 
shelly, and divided into two plates by a 
straight median suture (Fig. 49). They were 
described in 1811, by Parkinson, who called 
them trigoneUites, and pointed out the re- 
semblance of their internal structure to the 

cancellated tissue of bones. Their external 

Fig. 49. t surface is smooth or sculptured; the inner 

side is marked by lines of growth. Forty-five kinds are enume- 
rated by Bronn ; they occur in all the strata in which ammonites 
are found, and a single specimen has been figured byM. D'Archiac, 
from the Devonian rocks of the Eifel, where it was associated 
with goniatites.\ 

Calcareous mandibles, or rhyncholites (F. Biguet), have been 
obtained from all the strata in which nautili occur ; and from 
their rarity, their large size, and close resemblance to the man- 
dibles of the recent nautilus, it is probable that they belonged 
only to that genus. § In the Muschelkalk of Bavaria one 

* This form was discovered by the late Miss Mary Anning, the indefatigable collector 
of the lias fossils of Lyme Eegis, and described by Mr. Strickland, Geol. Journal, vol. i., 
p. 232. Also by M. Voltz, Mem. de I'lnstitiit, 1837, p. 48. 

t Tricjonellites lamellosiis. Park. Oxford clay, Solenhofen (and Chippenham), 
associated with ammonites lingulatus, Quenstedt. (= A. Brightii, Pratt). From a 
specimen in the cabinet of Charles Stckes, Esq. 

X The triyonellites have been described by Meyer as bivalve shells, under the generic 
name of aptychus ; by Deslongchamps under tlie name of Munsteria. M. D'Orbigny 
regards them as cirripedes ! M. Deshayes believes them to be gizzards of the 
ammonites. M. Coquand compares them with teudopsis; an analogy evidently sug- 
gested by some of the membranous and elongated forms, such as T. sanguinolarius, 
found with am. depressus, in the lias of Boll. Ruppell, Voltz, Quenstedt, and Zieten, 
regard the trigonellites as the operada of ammonites, an opinion also entertained by 
many of the most experienced fossil collectors in England. Some of them have been 
described by Eolle (1862) as Cydidia and Scaphanidia. 

§ M, D'Orbigny has manufactured two genera of calamaries out of these nautilua 
beaks (rhi/nchoteuthis and palceoteuthis). In the innnmerable sections of ammonites 
which have been made, no traces of the mandibles have ever been discovered. 



CEPHALOPODA. 183 

nautiltis (JV. arietis, Eemecke,==N. bidorsatus, ScHotlieim), is 
found, and two kinds of rhynchoUte ; one sort, corresponding 
with the upper mandible of the recent nautilus, has been called 
" rhyncholites hirundo" (PI. II., Fig. 11); the other, which 
appears to be only the lower mandible of the same species, has 
been described under the name of " conchorhynchus avirostris."* 
They also occur in the belemnite beds of the middle lias of 
Dorsetshire ; these latter are very different in form from those 
of nautili in the lower lias, and may probably belong to 
belemnites. 

In studying the fossil tetrahrancMata, it is necessary to take 
into consideration the varying circumstances under which they 
have been preserved. In some strata (as the lias of Watchett) 
the outer layer of the shell has disappeared, whilst the inner 
nacreous layer is preserved. More frequently only the outer 
layer remains ; and in the chalk formation the whole shell has 
perished. In the calcareous grit of Berkshire and Wiltshire the 
ammonites have lost their shells ; but perfect casts of the 
chambers, formed of calcareous spar, remain. -j* 

Eossil orthocerata and ammonites are evidently in many 
instances dead shells, being overgrown with corals, serpulae, or 
oysters ; every cabinet affords such examples. In others the 
animal has apparently occupied its shell, and prevented the 
ingress of mud, which has hardened all around it ; after this it 
has decomposed, and contributed to form those phosphates and 
sulphides commonly present in the body-chamber of fossil shells, 
and by which the sediment around them is so often formed into 
a hard concretion. J In this state they are permeated by mineral 
water, which slowly deposits calcareous spar, in crystals, on 
their walls ; or by acidulous water, which removes every trace 
of the shell, leaving a cavity, which at some' future time may 
again become filled with spar, having the form of the shell but 
not its structure. In some sections of orthocerata it is evident 
that the mud has gained access to the air-cells ; but the cham- 
bers are not entirely filled, because their lining membrane has 
contracted, leaving a space between itself and certain portions 
of the walls, which correspond in each chamber. 

The tetrabranchs could undoubtedly swim, by their respira- 
tory jets ; but the discoidal nautili and ammonites are not well 

* Lepas avirostris (ScMotheim), described by Blainville as the beak of a brachiopodj 

t Called spondylolites by old -writers. 

X In he alum-shale of Whitby innumerable concretions are found, which, -when 
struck with the hammer, split open and disclose an ammonite. See Dr. Mantell's 
" Thoughts on a Pebble," p. 21. 



184 MANTTAL OP THE MOLLtJSCA. 

calculated, by their fonns, for swimming; and tlie straight* 
shelled orthocerata and hacuUtes must have held a nearly vertical 
position, head downwards, on accotint of the buoyancy of their 
shells. The use of the air-chambers is to render the whole 
animal (and shell) of nearly the same specific gravity with the 
Water.* The object of the numerous pa,rtitions is not so much 
to sustain the pressure of the water, as to guard against the 
collisions to which the shell is exposed. They are most compli- 
cated in the ammonites, whose general form possesses least 
strength, f The purpose of the siphuncle (as suggested by Mr. 
Searles Wood) is to maintain the vitality of the shell during the 
long life which these animals certainly enjoyed. Mr. Forbes 
has suggested that the inner course of the hamites broke off as 
the outer ones were formed. But this was not the case with the 
vrthocerata, whose long straight shells were particularly exposed 
to danger ; in these the preservation of the shell was provided 
for by the increased size and strength of the siphuncle, and 
its increased vascularity. In endoceras we find the siphuncle 
thickened by internal deposits, until in some of the very cylin- 
drical species it forms an almost solid axis. 

The nucleus of the shell is rather large in the nautili, and 
causes an opening to remain through the shell, until the umbilicus 
is filled up with a callous deposit ; several fossil species have 
always a hole through the centre. 

In the ammonites, the nucleus is exceedingly small, and the 
whorls compact from the first. 

It has been stated that the septa are formed periodically ; but 
it must not be supposed that the shell-muscles ever become 
detached, or that the animal moves the distance of a chamber 
all at once. It is most likely that the adductors grow only in 
front, and that a constant waste takes place behind, so that they 
are always moving onward, except when a new septum is to be 
formed ; the septa indicate periodic rests. 

The consideration of this fact, that the nautilus must so 
frequently have an air-cavity between it and its shell, is alone 
sufficient to convince us that the chambered cephalopods could 



* A nautilus pompilius (in the cabinet of Mr. Morris) weighs lib., and when the 
siphuncle is secured, it floats with a ^Ib. weight in its aperture, The animal would 
have displaced two pints (= 2 jibs.) of water, and therefore, if it weighed 3lbs., the 
epecific gravity of the animal and shell would scarcely exceed that of salt water. 

t The siphuncle and lobed septa did not hold the animal in its shell, as Von Buch 
imagined : tliat was secured by the shell-muscles. The complicated sutures perhaps 
indicate lobed ovaries ; they occur in genera which must have produced very small 
eggs. 



CEPHALOPODA. 185 

not exist in very deep water. They were probably limited to 
a depth of 20 or 30 fathoms at the utmost.* 

It is certain that the sexes were distinct in the tetralranchiata. 
M. D'Orbigny, noticing that there were two varieties of almost 
every kind of ammonite — one compressed, the other inflated 
— naturally assumed that the first were the shells of male indi- 
viduals (s), the second of females (9). Dr. Melville has made 
a similar suggestion with respect to the nautili ; namely, that 
the umbilicated specimens are the males, the imperforated shells, 
females. Professor Yan der Hoeven has described the diff'erence 
in the shells of the two sexes ; f but these are trivial as com- 
pared with those presented by the animals. The most marked 
is that while the female has twelve retractile tentacles, the male 
has only eight, while the other four tentacles are coalesced 
together to form an organ called the spadix. 

In 1865, M. Barrande published the plates to his second 
volume on the Cephalopods of Bohemia. We have not been 
able to see this work : but it contains 107 plates, with figures of 
200 species of cephalopods, belonging to the genera Goniatites, 
Nothoceras, Trochoceras, Hercoceras, Lituites, Fhragmoceras, Oom- 
phoceras, and Ascoceras. 

Family I. — ^NAUTrLiD^. 

Shell. Body-cJiamher capacious. Aperture simple. Sutures 
simple. Sijphuncle centTal or intemal, (Pigs. 50, 51.) 

Nautilus, Breynius, 1*732. 

Shell involute or discoidal, few-whorled. Siphuncle central or 
sub -central. 

In the recent nautili, the shell is smooth, but in many fossil 
species it is corrugated, like the patent iron-roofing, so remark- 
able for its strength and lightness. (Buckland.) See PL II., 
Fig. 10. 

The umhilicus is small or obsolete in the typical nautili, and 
the whorls enlarge rapidly. In the palaeozoic species, the 
whorls increase slowly, and are sometimes scarcely in contact. 
The last air-cell is frequently shallower in proportion than the 
rest. 

* By deep water, naturalists and dredgers seldom mean more than 25 fathoms, a 
comparatively small depth, only found near coasts and islands. At 100 fathoms the 
pressure exceeds 2651bs. to the square inch. Empty bottles, securely corked, and sunk 
with weights beyond 100 fathoms, are always crushed. If filled with liquid, the cork 
is driven in, and the hquid replaced by salt water ; and in drawing the bottle up again 
the cork is returned to the neck of the bottle, generally in a reversed position. (Sir F. 
Beaufort. ) 

t Annals of Natural Histpry, vol. xix. 1857. 



186 



MANUAL OF THE MOLLTJSCA. 



Animal. In the recent nautilus, the mandibles are horny, 
but calcified to a considerable extent ; they are surrounded by 
a circular fleshy lip, external to which are four groups of lahial 
tentacles, twelve or thirteen in each group ; they appear to answer 




Fig. 50. Nautilus pompilius in its shell.* 

to the huccal memlrane of the calamary (Fig. 1). Beyond these, 
on each side of the head, is a double series of arms, or brachial 
tentacles, thirty-six in number ; the dorsal pair are expanded, 
and united to form the hood, which closes the aperture of the 
shell, except for a small space on each side, which is filled by 
the second pair of arms. The tentacles are lamellated on their 
inner surface, and are retractile within sheaths, or " digita- 
tions," which correspond -to the eight ordinary arms c^ the 

* This woodcut and eighteen others illustrating the tetrabranchiata, are the property 
of Dr. Gray, to whom we are indebted for their use. Fig. 50 represents the recent 
nautilus, as it appears on the removal of part of the outer shell-wall (from the 
specimen in the British Museum). The eye is seen in the centre, covered bj' the hood 
(h) ; t, tentacles, nearly concealed in their sheaths ; /, funnel ; m, margin of the 
mantle, very much contracted ; n, nidamental gland ; a, c, air-cells and siphuncle ; s, 
portion of the shell ; a, shell-muscle. The internal organs are indicated by dotted 
lines ; b, branchiae ; h, heart and renal glands ; c, crop ; g, gizzard ; /, liver ; o, ovary. 



CEPKALOPODA. 187 

cuttle-fisLes ; their superiority in number being indicative of a 
lower grade of organisation. Besides these there are four ocular 
tentacles, one behind and one in front of each eye ; they seem 
to be instruments of sensation, and resemble the tentacles of 
doris and ajplysia, (Owen.) On the side of each eye is a hollow 
plicated process, which is not tentaculiferous. This process 
bears the external ears. The cavity leads to the auditory cap- 
sule, along a passage lined with a glandular membrane. The 
respiratory funnel is formed by the folding of a very thick 
muscular lobe, which is prolonged laterally on each' side of the 
head, with its free edge directed backwards into the branchial 
cavity ; behind the liood it is directed forwards, forming a lobe 
which lies against the black-stained spire of the shell (Fig. 50 s).* 
Inside the funnel is a valve-like fold (Fig. 51s). The margin 
of the mantle is entire, and extends as far as the edge of the 
shell : its substance is firm and muscular as far back as the 
line of the shell-muscles and horny girdle, beyond which it is 
thin and transparent. The shell-muscles are united by a narrow 
tract across the hollow occupied by the involute spire of the 
shell : and are thus rendered horse-shoe shaped. The siphuncle 
is vascular ; it opens into the cavity containing the heart {pen'- 
cardium), and is most probably filled with fluid from that 
cavity (Owen). 

Eespecting the habits of the nautilus very little is known : 
the specimen dissected by Professor Owen had its crop filled 
with fragments of a small crab, and its mandibles seem well 
adapted for breaking shells. The statement that it visits 
the surface of the sea of its own accord is, at present, uncon- 
firmed on observation, although the air-cells would doubtless 
enable the animal to rise by a very small amiount of muscular 
exertion. 

Professor Owen gives the following passage, from the old 
Dutch naturalist, Eumphius, who wrote, in 1705, an account of 
the rarities of Amboyna. ' ' When the nautilus floats on the 
water, he puts out his head and all his tentacles, and spreads 
them upon the water, with the poop of the shell above water ; 

* The funnel is considered to be the homologue of the foot of the gasteropods hj Loven, 
a conclusion with which we cannot agree. Tfee cephalopods ought to be compared with 
the larval gasteropods, in which the foot only serves to support an operculum ; or with 
the floating tribes in which the foot is obsolete, or serves only to secrete a nidamental 
latt iianthina). However, on examining the nautilus preserved in the British Museum, 
and finding that the funnel was only part of a muscular collar, which extends all round 
the neck of the animal, we could not avoid noticing its resemblance to the siphonal 
lappets of pahidina, and to that series of lappets (including the operculigerous lobe) 
wnich surrounds the trochus (Fig. 114). 



188 MAiniAL OF THE MOLLUSCA. 

but at tlie bottom he creeps in the reverse position, with his 
boat above him, and with his head and tentacles upon the 
ground, making a tolerably quick progress. He keeps himself 
chiefly upon the ground, creeping also sometimes into the nets 
of the fishermen ; but after a storm, as the weather becomes 
calm, they are seen in troops, floating on the water, heing driven 
tip hy the agitation of the waves. This sailing, however, is not of 
long continuance ; for having taken in all their tentacles, they 
upset their boat, and so return to the bottom." 




Fig. 51. Nautilus expanded.* 

Distribution, 3 or 4 species. Chinese seas, Indian Ocean, 
Persian Gulf. 

Fossil, about 188 species. In all strata, South and North 
America (Chili). Europe. S. India. 

There are two types of ornamentation in nautili — the smooth 
and the longitudinally striated; the latter are almost exclu- 
sively oolitic, and at present only 1 species is known in Indian 
cretaceous rocks ; the smooth type is almost exclusively cre- 
taceous, and is abundantly represented in India. D'Orbigny 

* Ideal representation of the nautilus, when expanded, by Professor Loven, who 
appears to have taken the details from M. Valenciennes' Memoir in the Archives du 
Museum, vol. ii., p. 257. A, hood; s, siphon. It is just possible that when the 
nautilus issues from its shell, the gas contained in the last, inconjplete, air-chambep 
may expand ; but this could not happen under any great pressure of water. 



CEPHALOPODA. 1 89^ 

has taken advantage of these characters for dividing the nautili 
into three groups, viz., 1. Lcevigati. Nautili with smooth shells 
ranging from the Permian epoch to the present time ; 2. Radiati. 
Shells ornamented with transverse ribs, mainly cretaceous ; 
and 3. Striati. Shells ornamented with longitudinal striae. 
These are confined to the oolite in Europe. In India a few 
species occur in the lower chalk. 

Sub-genus. Aturia (Bronn). = Megasiphonia, D'Orb. 

Type, N. zic-zac, Sby. PI. II., Pig. 12, London Clay, 
Highgate. 

Shell, sutures with a deep lateral lobe ; siphuncle nearly 
internal, large, continuous, resembling a succession of funnels. 

Fossil, 4 species. Eocone ; North America, Europe, India. 

Suh-genus ? Discites, McCoy. Whorls all exposed ; the last 
chamber sometimes produced. 

Fossil, 5 species. Lower Silurian. — Carb. limestone. 

Temnocheilus, McCoy. Pounded on the carinated species of 
the carb. limestone, of which 5 are known. 

Cryptoceras, D'Orb. Ascoceras, Barr. Pounded on N. dor- 
salis, Phil., and one other species, in which the siphuncle is 
nearly external. 

Fossil, 16 species. Upper Silurian — Carb. 

LiTUITES, Breynius. 

Etymology, lituus, a, trumpet. 

Synonyms, Hortolus, Montf. (whorls separate), Trocholites, 
Conrad. 

Example, L. convolvans, Schl. L. lituus, Hisinger. 

Shell, discoidal ; whorls close or separate ; last chamber pro- 
duced in a straight line ; siphuncle central or sub-central. 

Fossil, 18 species. Silurian ; North America, Europe. 

Teochoceeas, Barrande, 1848. 

Example, T. trochoides. Bar. 

Shell nautiloid, spiral, depressed. 

Fossil, 4:4: species. Upper Silurian ; Bohemia. 

Some of the species are nearly flat, and, having the last 
chamber produced, would formerly have been considered 
Lituites. 



190 MANUAL OF THE MOLLUSC A. 





Fig. 52. Clymenia striata, Munst.* Fig, 53. C. linearis, Munst. 

Clymenia, Munster, 1832. 

Etymology, Clymene, a sea-nymph. 

Synonyms, Endosiphoiiites, Ansted. Sub-clymenia, D'Orb. 

Example, C. striata, PL II., Pig. 16 (Mus. Tennant). 

Shell discoidal ; septa simple or slightly lobed ; siphuncle 
internal. 

Fossil, 45 species. Upper Silurian — Mount. Limestone. 
North America, Europe. 

Family II. — ORTHocERATiDiE. 

Shell straight, curved, or discoidal; iody chamber small; 
aperture contracted, sometimes extremely narrow (Eigs. 48, 
49) ; siphuncle complicated. 

It seems probable that the cephalopods of this family were 
not able to withdraw themselves completely into their shells, 
like the pearly nautilus ; this was certainly the case with some 
of them, as M. Barrande has stated, for the siphonal aperture 
is almost isolated from the cephalic opening. The shell appears 
to have been often less calcified, but connected with more 
vascular parts than in the nautilus ; and the siphuncle often 
attains an enormous development. In all this, there is nothing 
to suggest a doubt of their being tetrahranchiate ; and the chevron- 
shaped coloured bands preserved on the orthoceras anguUferus,-\ 
suflB.ciently prove that the shell was essentially external. 

Orthoceras, Breyn. 

Etymology, orthos, straight, and ceras, a horn. 

Synonyms, Cycloceras, McCoy. Gonioceras, Hall. J Conoceras, 
Br, nn. 

Example, 0. Ludense (diagram of a longitudinal section) 
PI. II., Fig. 14. 

Shell straight; siphuncle central; aperture sometimes con- 
tracted. 

Fossil, 240 species. Lower Silurian — Lias ; North America, 
Australia, and Europe. 

* Figs. 52, 53. Sutures of two species of Cljonenia from Phillips' Pal. Fos., Devon- 
shire, t Figured by D'Archiac and Verneuil, Geol. Trans. 

X Ikeca and Tentaculites are provisionally placed with the Fteropoda : they pro- 
bably belong here. 



CEPHALOPODA. 



191 



The ortJiocerata are tlie most abundant and wide-spread shells 
of the old rocks, and attained a larger size than any other fossil 
shell. A fragment of an orthoceras, in the collection of Mr. 
Tate of Alnwick, is a yard long, and 1 foot in diameter, its 
original length must have been 6 feet. Other species, 2 feet in 
length, are only 1 inch in diameter at the aperture. 

Suh-genus. 1. Cameroceras, Conrad (= meliaand thoracoceras, 
Pischer ?). 

Siphunde lateral, sometimes very large. {simple ?). 

Casts of these large siphuncles were called liyolites by Eichwald. 

27 species. Lower Silurian — Trias ? North America and 
Europe. 





Fig. 54. Actinoceras.* 



Fig. 55. Onnoceras. 



2. Acfinoceras (Bronn), Stokes. Siphuncle very large, in- 
flated between the chambers, and connected with a slender 
central tube by radiating plates.^ 6 species. Lower Silurian — 
Carb. ; North America, Baltic, and Brit. 

3. Ormoceras, Stokes. Siphuncular beads constricted in the 
middle (making the septa appear as if united to the centre of 
each). 3 species. Lower Silurian — Devon; North America. 
This sub-genus very much resembles, if it is not identical with, 
the last mentioned. 

4. Huronia, Stokes. Shell extremely thin, membranous or 
horny ? Siphuncle very large, central, the upper part of each 
joint inflated, connected with a small central tube by radiating 
plates. 3 species. Lower Silurian. Drummond Island, Lake 
Huron. 

Numerous examples of this curious fossil were collected by Dr. 
Bigsby (in 1822), and by the officers of the regiments formerly 

* Fig. 54. Actinoceras Richardsoni, Stokes. Lake Winipeg. (Diagram reduced ^.) 
Fig. 55. Ormoceras Bayfieldi, Stokes. Drummond Island. (From Mr. Stokes' paper^ 
Geol. Trans.) 



192 



MANUAL OF THE MOLLTJSCA. 



stationed on Drammond Island. Specimens have also been 
brought home by the ofEcers of many of the Arctic expeditions. 
But "with, the exception of one formerly in the possession of 





Fig, 56. Huronia vertebralis.* 

Lieutenant Gibson, and another in the cabinet of Mr. Stokes, 
the siphuncle only is preserved, and not a trace remains of septa 
or shell wall. Some of those seen by Dr. Bigsby in the lime- 
stone cliffs were 6 feet in length. 

5. Endoceras, Hall (Conotubularia, Troost). Shell extremely 
elongated, cylindrical. Siphuncle very large, cylindrical, lateral ; 
thickened internally by repeated layers of shell, or partitioned 
off by fiinnel-shaped diaphragms. 12 species. Lower Silurian, 
New York. 

Shell perforated by two distinct siphuncles ? 0. bisipho- 
natum Sby, Caradoc sandstone, Brit. 

" Orthocerata with two siphuncles have been observed, but 
there has always appeared something doubtful about them. 
In the present instance, however, this structure cannot be 
questioned." (J. Sowerby.) 

Small orthocerata of various species are frequently found in 
the body chamber and open siphuncle of large specimens, t The 
endoceras gemeUiparum and joroteiforme of Hall, appear to be 
examples of this kind. 

6. Tritoceras=Diploceras, Salter. The shell is supposed to 

* Fig. 56. Huronia vertebralis, Stokes, a from a specimen in the British Museum 
presented by Dr. Bigsby. The septa are added from Dr. Bigsby's drawing ; they were 
only indicated in the specimen by " colourless lines on the brown limestone." b repre- 
sents a weathered section, presented to the British Museum by Captain Kellett and 
Lieutenant Wood, of H.M.S. Pandora. The figures are reduced |. 

t Shells of Bellerophon and Murchisonia are found under the same circumstances. 



CrEPHALOPODA. 



193 



have resembled Oonioceras, and tlie external tube to be a simple 
cavity, formed by the approximation of the lateral angles. 

Disoosorus [conoideus) Hall, 1852. Pal. New York. This 
fossil appears to be a sipbuncle similar to those figured by Dr. 
Bigsby in 1824 (Geol. Trs. I., PL 30, f. 6), andwMch have been 
correctly referred to the orthocerata by Quenstedt. 
GoMPHOCEEAS, J. Sby. 1839. 

Etymology, gomphos, a club ; and ceras, a horn. 

Synonyms, Apioceras (Fischer). Poterioceras (McCoy). 

Tyoe, G. pyriforme, Sby., Pig. 5S, and G. Bohemicum, Bar. 
Fig. 47. 





Fig. 57. Endoceras.* Fig. 58. Gomphoceras.^ 

Shell, fusiform or globular, with a tapering apex; aperture 
contracted in the middle; siphuncle moniliform, sub -central. 

Distribution, 27 species. Lower Silurian — Garb. North 
America, Europe, Brit. Barrande figures 70 species in Yol. II. 
of his " Systeme Silurien," 1865, nearly aU of which are believed 
to be new. 

Oncoceeas, HaU. 

Etymology, oncos, a protuberance. 

Type, 0. constrictum, Hall. Trenton limestone. 

* Fig. 57. Diagram of an endoceras (after Hall), a, shell-wall; 6, wall of siphuncle * 
ecc, diaphragms ("embryo-tubes" of Hall). 

t Fig. 58. Gomphoceras pyriforme. L. Ludlow rock, Mocktree HUl, Herefordshire. 
JFrom Murchison's Silurian Syst. reduced ^.) s, beaded siphuncle. 



194 MAIfTJAL OF THE MOLLTJSCA. 

Shell, like a curyed gomphoceras ; sipliiincle external. 
Distribution, 3 species. Silurian, New York. 

Phragmocebas, Broderip. 

Etymology, phragmos, a partition, and ceras, a horn. 

Type, P. yentricosum (Steininger species), PL II., Pig. 15. 

Shell curyed, laterally compressed ; aperture contracted in the 
middle ; siphunde, yentral, radiated. Example, P. callistoma, 
Bar., Pig. 48. 

Distribution, 15 species. Lower Silurian — Carb. ; Brit., 
Germany. 

Cyhtoceeas, Goldf., 1832. 

Etymology, curtos, curyed, ceras, horn. 

Synonyms, Campulites, Desh., 1832 (including gyroceras). 
Aploceras, D'Orbigny. Campyloceras and trigonoceras, McCoy. 
Gyroceras, D'Orbigny. 

Example, 0. hybridum, Yolborthi, andBeaumonti (Barrande). 

Shell curyed ; siphunde small, internal, or sub-central. 

Fossil, 84 species. Lower Silurian — Carb. ; North and South 
America and Europe. 





Pig. 59.* 

Gtroceeas, Meyer, 1829. 
Etymology, gyros, a circle, and ceras. 
Synonym, Nautiloceras, D'Orbigny. 

Example, G. eifeliense, D'Arch. (PI. II., Pig. 13). Devonian; 
Eifel. 

* Fig. 59. Gyroceras Goldf ussii. {— omatifm Groldf.). b, siphimcle of G. depressum, 
Goldf. sp. Devonian. Eifel. From MM. D'Archiac and Vemeuil. 



CEPHALOPODA. 195 

Shell nautiloid ; whorls separate ; siphuncle excentric, radiated. 
Fossil, 17 species. Upper SiluriarL — Trias ? North America 
and Europe. 

Thoracoceras, Pischer, 1844. 

Synonym, Melia, Pischer (not L.). 

Type, T. yestitum. 

Shell straight, elongated, conical, witii a small lateral straight 
siphuncle. 

Fossil, 20 species. Lower Silurian — Garb. United States 
and Europe. 

NoTHOCERAS, Barrande, 1856. 
Shell nautiloid, slightly involute ; septa slightly arched, with- 
out lobes. 
Fossil, 1 species. Upper Silurian. 

Eajmeilt III. — Ammonitid^, 

Shell. Body -chamber elongated ; aperture guarded by processes, 
and closed by an operculum ; sutures angulated, or lobed and 
foliated; siphuncle external (dorsal, as regards the shell). 

The shell of the ammonitidce has essentially the same structure 
as that of the nautilus. It consists of an external porcellanous* 
layer, formed by the collar of the mantle only and of an internal 
nacreous lining, deposited by the whole extent of its visceral 
surface. There is an ammonite in the British Museum, evidently 
broken and repaired during the life of the animal, f which shows 
that the shell was deposited from within. In some species of 
ammonites the collar of the mantle forms prominent spines on 
the shell, which are too deep for the visceral mantle to enter ; 
they are thereiore partitioned off {as in A. armatus. Lias) from 
the body whorl and air cells, and not exhibited in casts. 

The baculites and ammonites of the section cristati acquire, 
when adult, a process projecting from the outer margin of their 
shell. Certain other ammonites (the ornati, coronati, &c.) form 
two lateral processes before they cease to grow (PI. III., Pig. 5). 
As these processes are often developed in very small specimens, 
it has been supposed that they are formed repeatedly in the life 
of the animal (at each periodic rest) and are again removed when 
growth recommences. These small specimens, however, may 
be only dwarfs. In one ammonite, from the inferior oolite of 
Normandy, the ends of these lateral processes meet, ' ' forming 

* Its microscopic structure has not been satisfactorily examined ; Professor Forbea 
detected a punctate structure in one species. 

t A. serpentinus, Schloth, U. Lias, Wellingboro. Eev. A. W. Griesbach. 

k2 



196 MANUAL OF THE MOLLTJSCA. 

an arcL. over the aperture and dividing it into two outlets, one 
corresponding with that above the hood of the nautilus, which 
gives passage to the dorsal fold of the mantle ; the other with, 
that below the hood, whence issue the tentacles, mouth, and 
funnel ; such a modification, we may presume, could not take 
place before the termination of the growth of the individual."* 
(Owen.) 

M. D'Orbigny has figured several examples of deformed 
ammonites, in which one side of the shell is scarcely developed, 
and the keel is consequently lateral. Such specimens probably 
indicate the partial atrophy of the branchiae on one side. In 
the British Museum there are deformed specimens of A. ohtusus, 
amaltheus, and tubercv2atu8. 





Fig. 60.t 

GomATiTES, De Haan. 

Etymology, gonia angles, (should be written gonialites ?). 
Synonym, aganides, D'Orbigny (not Montf=^^wna zic-zac). 
Examples, Or. Henslowi (PI. III., Fig. 1), Gr. sphericus (Figs. 
60 and 46). 

Shell discoidal ; sutures lobed ; siphuncle dorsal. 
Distribution, 197 species. Upper Silurian — Trias. Europe. 

Ehabdoceeas, Hauer, 1860. 

Shell straight, orthoceratoid, with bold sculpture. Sej^fa 
with rounded lobes. 

Distribution, 1 species. Trias. Germany. 

* This unique and abnormal specimen is in the cabinet of S. P. Pratt, Esq. 

t Kg. 60. Goniatites sphericus, Sby. Front and side views of a specimen from the 
carb. limestone of Derbyshire, in the cabinet of Mr. J. Tennant ; the body-chamber 
and shell-wall have been removed artificially. 



CEPHALOPODA. 



197 



Bactrites, Sandberger (=stenoceras, D'Orbigny ?). 

Shell straight ; sutures lobed. 

Type, B. subconicus, Sbger. 

Distribution, 3 species. Devonian, Germany. 

Fig. 61.* 

Ceratites, De Haan. 

Type, C. nodosus (PI. III., Fig. 2). 

Shell discoidal ; sutures lobed, the lobes crenulated (Fig. 61). 

Distrihution, 29 species. Devonian — Chalk. Europe, India. 

M. D'Orbigny describes five shells from the gault and Upper 
greensand as ceratites ; but many ammonites have equally simple 
sutures, when young. 




Fig. 03. t 

Ammonites, Bruguiere. 

Etymology, ammon, a name of Jupiter, worshipped in Libya 
under the form of a ram. The ammonite is the cornu ammonis of 
old authors. 

Synonyms, Orbulites, Lam. Planulites, Montf. 

Shell discoidal ; inner whorls more or less concealed ; septa 
undulated ; sutures lobed and foliated ; siphuncle dorsal. 

* Fig. 61. Suture of ceratites nodosus (Brug). Tlie arrow in the dorsal lobe points 
towards the aperture. 

T Fig. 62. Ammonites rostratus (Sby.) From the U. greensand of Devizes, in tho 
cabinet of W. Cunnington, Esq. b, front view of one of its partitions. 



19S 



MANUAL OF THE MOLLUSCA. 



Distribution, about 700 species. Trias — Chalk. Coast of 
Chili (D'Orbigny), Santa Ee de Bogota (Hopkins), New Jersey, 
Europe, South India, and New Zealand. 

In this, as in almost every case, the figures represent the 
number of species which have been described, and which gene- 
rally pass current as species. It is very probable that when all 
the forms have been thoroughly examined many may turn out 
to be nothing more than variations of the same species, due to 
difibrences of age, &c. Thus, according to Mr. Seeley, the Am- 
Tuonites splendens from the greensand of Cambridge, comprises 
not only the form so-named, but fourteen others occurring in 
the same bed, and which have received distinctive specific names ; 
A. planulatus is made up of five so-called species. Looked at 
from this point of view the 700 would be replaced by a much 
smaller number. 

Captain Alexander Gerard discovered ammonites similar to 
our L. oolitic species, in the high passes of the Himalaya, 16,200 
feet above the sea. 

Section A. Back luitli an entire heel. 

1. Arietes, L. oolites, A. bifrons (PL III., Tig. 6), bisul- 

catus (PI. III., Fig. 7). 

2,. Falciferi, L. oolites, A. serpentinus, radians, hecticus. 

3. Cristati, cretaceous, A. cristatus, rostratus (Fig. 62), 

varians. 



B. Bach crenated. 



4. Amalthei, ool. 

5. Bothomagenses, cret. 



A. amaltheus, cordatus, excavatus. 

A, rothomagensis, from Bothoma- 

gum, Eouen (PI. III., Fig. 4). 







C. 


Bach sliarp. 


6. 


Disci, 


oolitic, 


A. discus, clypeiformis. 






D. 


Bach cJiannelled. 


7. 


Dentati, 


j cret. 
]ool. 


A. dentatus, lautus. 

A. Parkinsoni, anguliferus. 






E. 


Bach squared. 


8. 

9. 

10. 


Armati, 

Capricorni, 

Ornati, 


L. ool. 
L. ool. 
ool. 


A. armatus, athletus, perarmatus. 
A. capricornus, planicostatus. 
A. Duncani, spinosus (PI. III., 
Eig. o). 



CEPHALOPODA. 



199 



11. HeteropJiylU, 

12. Ligati, 



P. JBacJc round, convex, 

L. ool. A. heterophyllus (Fig. 41). 
cret. A. planulatus (PL III., Fig. 3). 




Fig. 63. Ammonites coronatus* 

13. Annulati, ool. A. annulatus, biplex, giganteus. 

14. Coronati, ool. A. coronatus (Fig. 63), sublaevis. 

15. Fimhriati, ooL A. fimbriatus, lineatus, hircinus. 

16. Cassiani, 36 species of very variable form, and remarkable 
for tbe number and complexity of their lobes. Trias, Austrian 
Alps. 




Fig. 64. t 

Examples, A. Maximiliani (Fig. 64), A. Metternicbii. 

Ceioceeas, Leveille. 

Etymology, krios, a ram, and ceras, a horn. 
Synonym, Tropseum, Sby. 

Example, 0. cristatum, D'Orbigny (PI. III., Fig. 8). 
>S7ieZZ discoidal ; whorls separate. 

Distribution, 13 species. Neocomian — Upper greensand. 
Britain, France. 

* Fig. 63. Profile of Ammonites 'coronahis (Brug.). (Reduced | from D'Orbigny.) 
Kelloway Eock, France, d I, dorsal lobe ; s s, dorsal saddles ; I' I' lateral lobes ; s' s', 
laferal saddles ; accessory and ventral lobes. The number of accessory lobes increases 
with age. 

t Fig. 64. Am. Maximiliani, Klipstein. {= A. bicarinatus, Miinst.) Trias, Hallstadt 
(copied from Quenstedt). A, profile, showing the numerous lobes and saddles; B, 
suture of one side ; v, dorsal saddle. 



200 MANUAL OF THE MOLLUSCA. 

ToxocEEAS, D'Orbigny. 

Etymology, toxon, a bo"w, ceras, a h.orn. 
Example, T. annulare, D'Orbigny (PL III., Fig. 12). 
Shell bow-shaped ; like an ammonite uncoiled. 
Distribution, 20 s^QciQS. Neocomian, Between this and mo- 
ceras and ancyloceras there are numerous intermediate forms. 

An CYLO CERAS, D'Orbigny. 

Etymology, anculos, incurved. 

Synonym, Anisoceras, Pictet. 

Example, A. spinigerum (PI. III., Fig. 10). 

Shell at first discoidal, with separate whorls ; afterwards pro- 
duced at a tangent and bent back again, like a hook or crosier. 

distribution, 38 species. Inferior oolite — chalk. South America 
(Cliili and Bogota), Europe. 

ScAPniTES, Parkinson. 

E jmology, scaphe, a boat. 
Example, S. equalis (PI. III., Fig. 9). 

Shell at first discoidal, with close whorls; last chamber detached 
and lacurved. 
List, ihution, 19 species. Oolite — Chalk. Europe, India. 

Helicoceras, D'Orbigny. 

Etym,ology, helix [helicos), a spiral, and ceras, a horn. 

Example, H. rotundum, Sby. species (PI. III., Fig. 11 — 
diagram). 

Shell spiral, sinistral ; whorls separate. 

Distribution, 11 species. Inferior oolite? — Chalk. Europe, 
India. 

TURRIUTES, Lam. 

Etymology, turris, a tower, and lithos, a stone. 

Shell spiral, sinistral ; aperture often irregular. 

Distribution, 37 species. Gault — Chalk. Europe. 

The turrilite was perhaps dibranchiate by the atrophy of the 
respiratory organs of one side. M. D'Orbigny includes in this 
genus particular specimens of certain Lias ammonites which are 
very slightly unsymmetrical ; the same species occur with both 
sides alike. He also makes a genus {heteroceras) of two turrilites, 
in which the last chamber is somewhat produced and recurved. 
T. reflexus (Quenstedt, T. 20, Fig. 16) has its apex inflected and 
concealed. 



CEPHAloroBA. 201 

Hamites, Parkinson. 

Etymology, hamus^ a hook. 

Example, H. attenuatus (PI. III., Pig. 15). 

Shell hook-shaped, or bent upon itself more than once, the 
courses separate. 

Distrihiition, 58 species. Xeocomian — Chalk. South A.merica 
(Tierra del Puego), Europe, India. 

6 




a 
Fig. 65. Sutures of Hamites cylindraceus, Defr.* 

The inner courses of this shell probably break a^vay, or are 
*' decollated," in the progress of its gro^vth. (Forbes.) M. 
D'Orbigny has proposed a new genus, hamulina, for the twenty 
neocomian species. 

Ptychoceeas, D'Orbigny. 

Etymology, ptycJie, a fold. 

Example, P. emericianum, D'Orbigny (PI. III., Fig. 14). 

Shell bent once upon itseK; the two straight portions in 
contact. 

Distribution, 8 species. Neocomian — Chalk. Britain, France, 
India. 

Bactjutes, Lamarck. 

Etymology, haculus, a staff. 

Example, B. anceps (PI. III., Fig. 13). 

>S/jeZZ straight, elongated; aperture guarded by a dorsal process. 

Distribution, 17 species. Neocomian — Chalk. Europe, South 
America (Chili), India. 

Baculina^ D'Orbigny, 2 species. B. Eouyana. Neocomian. 
France. Sutures not foliated. 

The chalk of Normandy has received the name of haculite lime- 
stone, from the abundance of this fossil. 

* Fig. 65. Space between two consecutive sutures of the right side, from a specimen 
in the British Museiun. a, dorsal line ; b, ventral. Baculite limestone, Fresville. 

K'6 



^02 



MAirCTAL OF THE MOLLTJSCA. 



Chaptes II. 
CLASS II.— GASTEEOPODA. 

The gasteropoda, including land-snails, sea-snails, whelks, 
limpets, and the like, are the types of the moUusca ; that is to 
say, they present all the leading features of molluscous organisa- 
tion in the most prominent degree, and make less approach to 
the appearance and condition of fishes than the cephalopods, and 
less to the crustaceans and zoophytes than the bivalves. 

Their ordinary and characteristic mode of locomotion is 
exemplified by the common garden- snail, which creeps by the 
successive expansion and contraction of its broad muscular foot. 
These muscular movements may be seen following each other in 
rapid waves when a snail is climbing a pane of glass. 

The nuchohranchs are "aberrant" gasteropods, having the 
foot thin and vertical ; they swim near the surface of the sea in 
a reversed position, or adhere to floating sea-weed. 




Fig. G6. A nucleobranch.* 



The gasteropods are nearly aU ur symmetrical, the body being 
coiled up spirally, and the respiratory organs of the left side 
being usuaUy atrophied. In chiton and dentalium the hranchioe 
and reproductive organs are repeated on each side. 

A few species of cymba, Uttorina, jpaludina, and helix, are vivi- 
'parous ; the rest are oviparous. 

When first hatched the young are always provided with a 
shell, though in many families it becomes concealed by a fold of 
the mantle, or it is speedily and wholly lost.f 

The gasteropods form two natural groups ; one breathing air 

* Fig. 66. Carinaria cymbium, Desh. = C. cristata, L. sp; (after Blainville), Medi- 
terranean, p, proboscis ; t, tentacles ; b, branchiae ; s, shell ; /, foot ; d, disk. 

t M. Loven believes tliat the embryo shell of the nudibranchs falls off at the time 
they acquire a locomotive foot. 



gasteropoda: 



203 



(putmonifera), the otlier water (brancM/era). The water-breathers 
have at first a sraall nautiloid shell , capable of concealing them 
entirely, and closed by an operculum. Instead of creeping, they 
swim with a pair of ciliated fins springing from the sides of the 
J ead ; and by this means are often more widely 
disper ed than we should be led to expect from 
their adult habits ; thus some sedentary species 
of caly'ptrcea and chiton have a greater range 
than the "paper-sailor," or the ever-drifting 
oceanic-snail. 

At this stage, which may fairly be compared 
with the larval condition of insects, there is 
scarcely any difierence between the young of 
eoUs and aplysia, or huccinum, and verm,etus. (M, Edwards.) 

The development of the branchiferous gasteropods may be 
observed with much facility in the common river-snails (joalu- 
dina) ; which are viviparous, and whose oviducts in early summer 
contain young in all stages of growth, some being a quarter of 
an inch in diameter. 




fig. 67. 




Embryos scarcely visible to the naked eye have a well-formed 
shell, ornamented with epidermal fringes ; a foot and operculum; 
and the head has long delicate tentacula, and very distinct black 
eyes. 

The development of the pulmoniferous embryo is best seen in 
the transparent eggs of the fresh-water limneids ; these are not 
hatched until the young have passed the larval condition, and 
their ciliated head-lobes (or veil) are superseded by the creeping 
disk, or foot. 



* Fig. 67. Fry of Eolis (from Alder and Hancock), o, the operculum; the original 
is not larger than the letter o. 

t Fig. 68. Paludina vivipara, L. (original) ; the internal organs are represented as 
if seen through the shell. The ovary, distended with eggs and embryos, occupies the 
right side of the body whorl ; the gill is seen on the left ; and between them the 
termination of the aUmentary canal. Surrey Docks, June, 1850. 



204 MANUAL OF THE MOLLtTSCA, 

The development of the air-breathers goes on within the shell, 
and has been traced by Yan Beneden, Gegenbaur, and others 
in Limax, Yeronicella, Yitrina, Bulimns, and Helix. 

The shell of the gasteropods is usually spiral, and univalve ; 
more rarely tubular, or conical, and in one genus it is multivalve. 
The following are its principal modifications : — 

A. Eegularly spiral, 

a. elongated or turreted ; terebra, turrifella, 
h. cylindrical ; megaspira, pupa. 

c. short; huccmum. 

d. globular ; natica, helix. 

e. depressed; solarium. 

f. discoidal ; plano7'his. 

g. convolute ; aperture as long as the shell ; cyprcea, bulla, 
h. fasiform; tapering to each end, like/wsws. 

i. trochiform ; conical, with a flat base, like trochus. 
^.turbinated ; conical, with a round base, like hirho. 

I. few-whorled ; Helix hcemastoma. PI. XII., Fig. 1. 
m. many-whorled ; Helix poly gyrata. PL XII., Fig. 2. 
n. ear-shaped; haliotis. 

B. Irregularly spiral ; siliquaria, vermetus. 
0. Tubular; dentalium. 

D. Shield-shaped ; umbrella, parmophorus. 

E. Boat-shaped; navicella. 

F. Conical or limpet-shaped ; patella. 
Gr. Multivalve and imbricated ; chiton. 

The only symmetrical shells are those of carinaria, atlanta, 
dentalium, and the limpets.* 

Nearly all the spiral shells are dextral, or right-handed ; a 
few are constantly sinistral, like clausilia ; reversed varieties of 
many shells, both dextral and sinistral, have been met with. 

The cavity of the shell is a single conical or spiral chamber ; 
no gasteropod has a multilocular shell like the nautilus, but 
spurious chambers are formed by particular species, such as 
Triton corrugatus (Fig. 69), di-mdi Euomphalus pentangulatus ; or 
under special circumstances, as when the upper part of the spire 
is destroyed. 

Some spiral shells are complete tubes, with the whorls sepa- 
rate, or scarcely in contact, as scalaria, cyclostom,a, and valvata ; 

"* The curve of the spiral shells and their operoula and also of the Nautilus, is a 
logarithmic spiral; so that to each particular species may be annexed a number 
indicating the ratio of the geometrical progression of the dimensions of its whorls 
Eev. H. Moselej', " On geometrical Forms of Turbinated and Discoid Shells."— PAi7. 
Trans. Lond. 1838. Pt. 2, n. 351. 



GASTEEOPODA. 



206 



"but more commonly the inner side of the spiral tube is formed 
by the pre-existing whorls (Pig. 69). 

The axis of the shell, around which the whorls are coiled, is 
sometimes open or hollow ; in which case the shell is said to be 
perforated, or umbiUcated (e.g. solarium). The perforation may 
be a mere chink, or fissure [rima), as in lacuna; or it may bo 
filled up by a shelly deposit, as in many naticas. In other shells, 
like the triton, the whorls are closely coiled, leaving only a 
pillar of shell, or columella, in the centre : such shells are said 
to be imperforate. 



> apex. 



posterior canal. 




. J anterior canal. 

Fig, 69. Section of a spiral univalve.* 

The apex of the shell presents important characters, as it 
was the nucleus or part formed in the egg ; it is sinistral in 
the pj/ramidelUdce, oblique and spiral in the nucleohranchs and 
emarginulce, and mammillated in Turhinella pyrum and Fusua 
antiquus. 

The apex is directed backwards in all except some of the 
patellidce, in which it is turned forwards, oyer the animal's head. 

» Fig. 69, Longitudinal section of Triton corrugatus, Lam., from a specimen in the 
cabinet of Mr, Gray. The upper part of the spire has been partitioned off many times 
successively. 



206 MANUAL OF THE MOLLtTSCA. 

In the adult condition of some shells tlie apex is always truncated 
(or decollated) as in cylindrella and Bulimus decollatus ; in others 
it is only truncated when the animals have lived in acidulous 
Waters (e.g. cerithidea and pirena), and specimens may be 
obtained from more favourable situations with the points 
perfect. 

The line of channel formed by the junction of the whorls is 
termed the suture. 

The last turn of the shell, or hody-wTiorl^ is usually very 
capacious ; in the females of some species the whorls enlarge 
more rapidly than in the males (e.g. Buccinum undatum). The 
"base" of the shell is the opposite end to the apex, and is 
usually the front of the aperture. 

The aperture is entire in most of the vegetable feeders (Jiolos- 
tomata), but notched or produced into a canal, in the carnivorous 
families {siqhonostomata) ; this canal, or siphon, is respiratory in 
its ofhce, and does not necessarily indicate the nature of the 
food. Sometimes there is a posterior channel or canal, which 
is excurrent, or anal, in its function (e.g. strombidce. and ovulum 
volva) ; it is represented by the slit in scissurella, the tube of 
typhis, the perforation in fissurella, and the series of holes in 
haliotis. 

The margin of the aperture is termed the peristome ; sometimes 
it is continuous {cyclostoma), or becomes continuous in the adult 
(carocoUa) ; very frequently it is " interrupted," the left side of 
the aperture being formed only by the body- whorl. The right 
side of the aperture is formed by the outer lip (lalrum), the 
left side by the inner or columellar lip {labium), or partly 
by the body- whorl (termed the "wall of the aperture," by 
Pfeiffer). 

The outer lip is usually thin and sharp in immature shells, and 
in some adults (e.g. helicella and hulimulus) ; but more frequently 
it is thickened ; or reflected; or cuiled iRwards {inflected), as in 
cyprcea ; or expanded, as in pteroceras ; or fringed with spines, as 
in murex. When these fringes or expansions of the outer lip 
are formed periodically, they are termed varices. 

Lines of colour, or sculpture, running from the apex to the 
aperture are spiral or longitudinal, and others which coincide 
with the lines of growth are " transverse," as regards the whorls; 
but stripes of colour extending from the apex across the whorls 
are often described as "longitudinal" or "radiating," with 
respect to the entire shell. 

Shells which are always concealed by the mantle are colourless, 
like Umax and parmophorus ; and those which are covered by the 



GASTEEOrODA. 207 

mantle-lobes when the animal expands, acqtiire a glazed or 
enamelled surface, like tlie cowries ; when the shell is deeply 
immersed in the foot of the animal it becomes partly glazed, as 
in cymha. In all other shells there is an epidermis, although it 
is sometimes very thin and transparent. 

In the interior of the shell the muscular impression is horse- 
shoe shaped, or divided into two scars ; the horns of the crescent 
are turned towards the head of the animal. 

The operculum with which many of the gasteropods close the 
aperture of their shells, presents modifications of structure which 
are so characteristic of the sub-genera as to be worthy of particular 
notice. It consists of a horny layer, sometimes strengthened by 
the addition of calcareous matter on its exterior, and in its mode 
of growth it presents some resemblance to the shell itself. Its 
inner surface is marked by a muscular scar, whose lines bear no 
relation to the external lines of growth, and its form is unHke 
the muscular scar in the shell. It is developed in the embryo, 
within the Q^g, and the point from which it commences is termed 
the nucleus ; many of the spiral and concentric forms fit the 
aperture of the shell with accuracy, the others only close the 
entrance partially, and in many genera, especially those with 
large apertures (e.g. dolium, cassidaria, harjpa, navicella), it ia 
quite rudimentary or obsolete. 




JFig. 70. 'E.g. 71. Fig. 72, 



The operculum is described as — 

Concentric, when it increases equally all round, and the nucleus 
is central or sub-central, as in.jpaludina and amjpuUaria (PL IX., 
Fig. 26). 

Imbricated, or lamellar (Fig. 71), when it grows only on one 
side, and the nucleus is marginal, as in purpura, phorus, and 
paludoTnus. 

Claw-shaped, or unguiculate (Fig. 70), with the nucleus apical 
or in front, as in turbinella and fusus ; it is claw-shaped and 
serrated in stromhus (Fig. 76). 

Spiral, when it grows only on one edge, and revolves as it 
grows ; it is always sinistral in dextral shells. 

Faucispiral, or few-whorled (Fig. 73), as in littorina. 



208 MANUAL OF THE MOLttlSCA. 

Suh-spiral, or scarcely spiral, in melanict (PL YIII., Fig. 25*). 

MuJfispiral, or many-wliorled (Fig. 72), as in trochus, where 
they sometimes amount to twenty ; the number of turns which 
the operculum makes is not determined by the number of whorls 
in the shell, but by the curvature of the opening, and the neces- 
sity that the operculum should revolve fast enough to fit it 
constantly. (Moseley.) 

It is said to be articulated when it has a projection, as in nerita 
(Fig. 74). 

Too much importance, however, must not be attached to this 
very variable plate, as an aid to classification ; it is present in 
some species of voluta, oliva, conus, mitra, and cancellaria, but 
absent in others ; it is (indifferently) horny or shelly in the 
species of ampuUaria and natica ; in paludina it is concentric, in 
paludomus lamellar, in valvata spiral ; in solarium and cerithiumf 
it is multispiral or paucispiral. 

The researches of Dr. Loven* have led to many attempts being 
made to remodel the arrangement of the Gasteropoda by the aid 
of peculiarities in their dentition. Whatever improvements may 
be thus obtained, it does not appear desirable to introduce a new 
terminology for divisions long since well established, and already 
over-burdened with classical names. f 

The patterns, or types of lingual dentition, are on the whole 
remarkably constant ; but their systematic value is not uniform. 
It must be remembered that the teeth are essentially epithelian 
cells, and like other superficial organs liable to be modified in 
accordance with the wants and habits of the creatures. The 
instruments with which animals obtain their food are of all 
others m.ost subject to these adaptive modifications, and can 
never form the hasis of a philosophical system. J 

* Ofversigt af Kongl. Vetensk. Akad. Forhandl. 1847. 

t The following names were proposed by Troschel (in Wiegman's Handbuch der 
Zoologie, 1848) and Gray (An. Nat. Hist.) for the principal types of lingual dentition: — 

a. Tsenioglossa, teeth 3. 1. 3 ; Littoriiia, Natica, Triton. 

b. Toxoglossa, teeth 1. 0. 1; Conus, Terebra? 

c. Hamiglossa, teeth 1. 1. 1 ; Murex, Buccinum. 

d. Eachiglossa, teeth 0. 1. 0; Voluta, Mitra? 

e. Gymnoglossa, teeth ; PjTamidella, Cancellaria, Solarium? 
/. Ehipidoglossa. teeth 00, 1. 00; Nerita, Trochus. 

X The carnivorous opossums have teeth adapted for eating flesh, but are not on that 
account to be classified with the placental camivora. The lingual teeth, like the 
operculum, usually have a structure characteristic of the genera or sub-genera. Some- 
times they have a general uniform character throughout a whole family or group 
of families. In many cases they present minute differences which promise to be 
valuable aids for distinguishing closely allied species. For example. Patella athletica 
may be distinguished from the common limpet (P. vulgata) by its teeth. 



GASTEEOPODA. 



209 



Some of the gasteropoda can suspend themselves by glutinous 
threads, like Utiopa and Rissoa parva, which anchor themselves 
to sea-weeds (Gray), and cerithidae (Fig. 75), 
which frequently leaves its proper element, 
and is found hanging in the air. (Adams.) A 
West India land- snail {cydostoma suspensum) 
also suspends itself. (Guilding.) The origin 
'^ these threads has not been explained ; but 
some of the limaccs lower themselves to the 
ground by a thread which is not secreted by 
any particular gland, but derived from the 
exudation over the general surface of the body. 
(Lister, D'Orbigny.) 

The division of this extensive class into 
orders and families has engaged the attention 
of many naturalists, and a variety of methods 
have been proposed. Cuvier's classification was ^ig- 75. 

the first that possessed much merit, and several of his orders 
have since been united with advantage. 

System of Cuvier. System now adopted. 

Class. Gasteropoda, 
Order 1. Pectinibranchiata ^ 

2. Scutibranchiata {/-.i-n 7 7.^ -.r-n-, 

3. Cyclobranchiata f ^^^- ProsohrancMata, M. Edw. 




4. Tubulibranchiata / 

5. Pulmonata 

6. Tectibranchiata '^ 

7. Inferobranchiata V 

8. Nudibranchiata. J 
Class. Heteeopoda. 



Ord. Pidmonifera. 

Ord. OpistholrancMata, M. Edw. 

Ord. Nudeohranchiata, Bl. 



Obder I. Pbosobrajstchiata. 

Abdomen well developed and protected by a shell, into which 
the whole animal can usually retire. Mantle forming a vaulted 
chamber over the back of the head, in which are placed the 
excretory orifices, and in which the branchise are almost always 
lodged. JBranchicB pectinated, or plume-like, situated {proson) 
in advance of the heart. Sexes distinct. (M. Edwards.) 

Section A. Siphonostomata. Carnivorous Gasteropods. 

Shell spiral, usually imperforate; aperture notched or produced 
into a canal in front. Operculum horny, lamellar. 



210 



MANUAL OF THE MOLLrSCA. 



Animal provided with a retractile proboscis ; eye-pedicels con- 
nate with the tentacles ; margin of the mantle prolonged into a 
siphon, by which water is conveyed into the branchisti chamber ; 
gills one or two, comb-like, placed obliquely over the back. 
Species all marine. 

Family I. — STROMBroiE. Wing-shells. 

Shell with an expanded lip, deeply notched near the canal. 
Operculum claw-shaped, serrated on the outer edge. 

Animal iurnished with large eyes, placed on thick pedicels ; 
tentacles slender, rising from the middle of the eye-pedicels. 
Foot narrow, ill-adapted for creeping. Lingual teeth single ; 
uncini, three on each side. 

The strombs are carrion feeders, and, for molluscous animals, 
very active ; they progress by a sort of leaping movement, turn- 
ing their heavy shell from side to side. Their eyes are more 
perfect than those of the other gasteropods, or of many fishes. 




Fig. 76.* 

Stuombus, L. Stromb. 

Etymology, stromhos, a top. 

Type, S. pugiHs (PI. lY., Fig. 1). 

Shell rather ventricose, tubercular or spiny; spire short; 
aperture long, with a short canal above and truncated below ; 
outer lip expanded, lobed above, and sinuated near the notch of 

* Fig. 76. Strombus auris-Diance^ L. (after Quoy and G-aimard), Amboyna. p, pro- 
boscis, between the ej'e-pedicels ; /, foot, folded up ; o, operculum ; m, border of the 
mautle ; s, respiratory siphon. 



GASTEROPODA. 211 

the anterior canal. Lingual teeth. {S. floridus) *7 cusped ; tmcioi, 
1 tri-dentate, 2, 3 claw-sliaped, simple (Fig. 77).* 




Fig. 77. Stromhus. (Wilton). 

Btronibus (floridus) is described by Loven as having a non- 
retractile, produced muzzle, like Aporrhais. S. gihlerulus is 
represented by Dr. Bergh with all the uncini denticulated. 

Distribution, 65 species. West Indies, Mediterranean, Ecd 
Sea, India, Mauritius, China, New Zealand, Pacific, West 
America. On reefs, at low water, and ranging to 10 fathoms. 

Fossil, 5 cretaceous species; 3 species Miocene — . South 
Europe. There is a group of small shells in the eocene tertiary 
strata of England and France, nearly related to the living 
S. fissurellus, L., some of which have been placed with rosteU 
laria, because the notch in the outer lip is small or obsolete. 
They probably constitute a sub-genus, to which the name 
Rimella Ag., might be applied. Example, S. Bartonensis. PI. 
IV., Fig. 2. 

The fountain- shell of the West Indies, S. gigas, L., is one of 
the largest living shells, weighing sometimes four or five pounds ; 
its apex and spines are filled up with solid shell as it becomes 
old. Immense quantities are annually imported from the 
Bahamas for the manufacture of cameos, and for the porcelain 
works; 300,000 were brought to Liverpool alone in the year 
1850. (Mr. Archer.) 

Pteeoceras, Lam. Scorpion shell. 

Etymology, pteron, a wing, and ceras, a horn. 

Type, P. lambis. PL lY., Fig. 3. 

Shell like strombus when young ; outer lip of the adult pro- 
duced into several long claws, one of them close to the spire, 
and forming a posterior canal. 

Distribution, 12 species. India, China. 

* The lingual dentition of strombus resembles that of aporrhais, and is unlike that 
of the whelks ; but it is more probable that a-porrhdis is the representative of strombus 
than that it is very closely allied. 



212 MANUAL OF THE MOLLUSCA. 

Fossil, nearly 100 species are enumerated by D'Orbigny, 
ranging from the lias to the upper chalk ; many of them are 
more nearly related to aporrhais {cerithiadce). 

EOSTELLAEIA, Lam. 

Etymology, rostellum, a little beak. 

Synonym, Fusus, Humphreys. 

Example, E. curta. PI. IV., Fig. 4. 

Shell with an elongated spire ; whorls numerous, flat ; canals 
long, the posterior one running up the spire ; outer lip more or 
less expanded, with only one sinus, and that close to the beak. 

Distribution, 8 species. Eed Sea, India, Borneo, China. 
Mange, 30 fathoms. 

Fossil, 80 species. Neocomian — chalk (=aporrhais?). 6 species. 
Eocene — . Britain, France, &c. 

The old tertiary species have the outer lip enormously ex- 
panded, and smooth- edged ; they constitute the section hippo - 
chrenes of Montfort (e.g., Eost. ampla, Solander. London 
clay). 

Sub-genus? Spinigera, D'Orbigny. 1847. Shell like rostel- 
laria ; whorls keeled ; keel developed into a slender spine on the 
outer lip, and two on each whorl, forming lateral fi-inges, as in 
ranella. Fossil, 5 species. Inf. oolite — chalk. Britain, France. 

Seraphs, Montfort. (Terebellum, Lam.) 

Etymology, diminutive of terehra, an auger. 

Shell smooth, sub-cylindrical ; spire short or none ; aperture 
long and narrow, truncated below ; outer lip thin. 

Distribution, 1 species. China. Philippines, 8 fathoms. 
(Cuming.) 

Fossil, 5 species. Eocene — . London, Paris. 

The animal of terebellum has an operculum like strombus ; its 
eye-pedicels are simple, without tentacles. (Adams.) In one 
fossil species, T. fusiforme, there is a short posterior canal, as in 
rostellaria. 

Family II. — ^Mttbicid^. 

Shell with a straight anterior canal ; aperture entire behind. 

Animal with a broad foot; eyes sessile on the tentacles, cr at 
their base ; branchial plumes two. Lingual ribbon long, linear ; 
rachis armed with a single series of dentated teeth; uncini, 
single. Predatory on other mollusca. The two species belong- 
ing to the genus Cheletropis, Forbes -= Sinusigera, D'Orbigny, 



GASTEROPODA. 



213 



aro now kno"wn to have no affinity with the Atlantidse, but to 
be tbe larva form of species belonging to the Muricidse. 






Fig. T6. Murex tenuispina. (Wilton.) 

Mtjeex (Pliny), L. 

Types, M. palma-rosse, PI. lY., Fig. 10. M. tenuispina, PI. 
rV., Fig. 9. M. haustellum, PL lY., Fig. 8. M. radix, 
pinnatus. 

Shell ornamented with three or more continuous longitudinal 
varices ; aperture rounded ; beak often very long ; canal partly 
slosed; operculum concentric, nucleus sup-apical (PL lY., Fig. 
10) ; lingual dentition (M. erinaceus), teeth single, three 
3rested ; uncini single, curved. For dentition of M. tenuispina 
see Fig. Y8. 

Distribution, 220 species. World-wide ; most abundant on 
the West Coast of tropical America, in the Chinese Sea, West 
Coast of Africa, West Indies; ranging from low water to 25 
fathoms, rarely at 60 fathoms. 

Fossil, 164 species. Eocene — . Britain, France, Java, &c. 

A few of the species usually referred to this genus belong to 
pisania and trophon. 

The murices appear to form only one-third of a whorl 
annually, ending in a varix; some species form intermediate 
varices of less extent. M. erinaceus, a very abundant species on 
the coasts of the channel, is called " sting- winkle" by fisher- 
men, who say it makes round holes in the other shell-fish with 
its beak. (See p. 21.) The ancients obtained their purple dye 
from species of murex ; the small shells weise bruised in mortars, 
the animals of the larger ones taken out. (F. Col.) Heaps 
of broken shells of the M. trunculus and caldron- shaped holes 
in the rocks may still be seen on the Tyrian shore. (Wilde.) On 
the coast of the Morea there is similar evidence of the employ- 
ment of M. hrandaris for the same purpose. (M. Boblaye.) 

Typhis, Montfort. 
Etymology, typhos, smoke. 



214 MANUAL OF THE MOLLtTSCA. . 

Type, T. ptmgens. PL lY., Fig. 11. 

Shell like murex ; but having tubular spines between the 
varices, of which the last is open, and occupied by the excurrent, 
canal. 

Distribution, 9 species. Mediterranean, West Africa, Cape, 
India, Western America. — 50 fathoms. 

Fossil, 8 species. Eocene — . London, Paris. 

PiSANiA, Bivon, 1832. 

Etymology, a native of (the coast near) Fisa, in Tuscany. 

Synonyms, Pollia, En2dna, and Euthria (Gray). 

Types, P. maculosa. PI. lY., Eig. 14 (Enzina), zonati. PI. 
lY., Eig. 15. 

Shell with numerous indistinct varices, or smooth and spirally 
striated ; canal short ; inner lip wrinkled ; outer lip crenulated. 
Operculum ovate, acute ; nucleus apical. 

The pisanice have been usually confounded with huccinumy 
murex, and ricinula. 

Distribution, about 120 species. West Indies, Africa, India, 
Philippines, South Seas, Western America. 

Fossil, ? species. Eocene — Britain, Erance, &o. 

Eakella, Lam. Erog-shell. 

Synonym, ApoUon (Montfort and Gray). 

Types, E. granifera. PI. lY., Eig. 12. E. spinosa. 

Shell with two rows of continuous varices, one on each side. 
. Operculum ovate, nucleus lateral. 

Distribution, 58 species. Mediterranean, Cape, India, China, 
Australia, Pacific, Western America, Range, low- water to 20 
fathoms. 

Fossil, 23 species. Eocene — . 

TuiTON, Lam. 

Etymology, Triton, a sea-deity. 

Synonym, Persona (Montfort, Gray). 

Type, T. tritonis, L. species. PI. IV., Eig. 13. 

Shell with disconnected varices ; canal prominent ; lips denti- 
culated. 

Operculum ovate, sub-concentric. 

Distribution, 100 species. West Indies, Mediterranean, 
Africa, India, China, Pacific, Western America. Eanging from 



GASTEROPODA. 



215 



low water to 10 or 20 fathoms ; one minute species has been 
drv>dged at 50 fathoms. 




Fig. 79. One of the buccal pla es of Triton, ^ (Wilton.) 

Fossil, 45 species. Eocene — . Britain, France, &c. ChiH. 

The great tritcn {T. tritonis) is the conch b'own by the 
Australian and Polynesian Islandei s. A yery similar species 
{T. nodiferus) is found in the Medi.erranean, and a tard in the 




Fig. 80. Teeth of Tritov, 2.1. Q.. (WUton.) 

West Indios. The buccal plates and teeth of Triton are shown 
in Figs. 79, 80. 

Fasciolabia, Lam. 

Etymology y fasciola, a band. 

Type, F. tulipa. PI. V., Fig. 1. 

Shell fusiform, elongated ; whorls 
round or angular ; canal open ; 
columellar lip tortuous, with several 
oblique folds. Operculum claw- 
shaped. F. gigantea of the South 
Seas attains a length of nearly two 
feet. The teeth of Fasciolaria re- 
semble those of Fusus Islandicus. 




w 

Fig. 81. Fasciolaria Tarentina, 
(Wnton.) 

In Buccinum undatum, the 




median tooth has fiye, or rarely six denticles ; and Mr. Wilton 



216 MANUAL OP THE MOLLUSCA. 

has observed tliat B. limhosum, $ has the teeth seven cusped, 
while in the females they are six cusped. 

Distribution, 106 species. West Indies, Mediterranean, West 
Africa, India, Australia, South Pacific, Western America. 

Fossil, 30 species, U. chalk — . France. 

TURBINELLA, Lam. 

Etymology, diminutive of turbo, a top. 

Ty:pe, T. pyrum. PI. Y., Pig. 2. 

Shell thick ; spire short ; columella with several transverse 
folds. Operculum claw-shaped. Pig. 70. The chank-shell 
[T. pyrum) is carved by the Cingalese, and reversed varieties of 
it, from wliich the priests administer medicine, are held sacred. 

Distribution, 70 species. West Indies, South America, Africa, 
Ceylon, Philippines, Pacific, Western America. 

JFossil, 20 species. Miocene — . 

Sub-genera, Cynodonta (Schum.), T. cornigera. PI. Y., Pig. 3. 

LaUrus (Montfort), T. gilbula. PI. Y., Pig. 4. 

Lagena (Schum.), T. Smaragdula, L. species. Northern 
Australia. 

CAIiTCELLAEIA, Lam. 

Etymology, cancellatus, cross-barred. 

Type, C. reticulata. PL Y., Fig. 5. 

Shell cancellated ; aperture chanelled in front ; columella with 
several strong oblique folds ; no operculum. The animals are 
vegetable feeders. (Desh.)* 

Distribution, 71 species. West Indies, Mediterranean, West 
Africa, India, China, California. 

Fossil, 60 species. Up. Chalk — . Britain, France, &c. 

Admete (viridula) is a boreal form of Cancellaria, without 
plaits. 

DlBAPHTJS, Phi. 

Synonym, conohelix edentulus. (Sw.) Shell subcylindrical, 
spire acute ; aperture narrow, linear, edentulous, excised at the 
base; lip thickened, rectilinear, rounded and abbreviated below. 

Trichothopis, Broderip, 1829. 

Etymology, Thrix (trichos), hair, and tropis, keel. 
Type, T. borealis,'Pl. YL, Fig. 8. (= ? Admete, Phil., no 
operculum). 

* Cancellaria and trichotropis form a small natural family connected with cerithiacUe 
and strombida. 



GASTEEOPODA. 217 

Shell thin, umbilicated ; spirally furrowed ; the ridges with 
epidermal fringes ; columella obliquely truncated ; operculum 
lamellar, nucleus external. 

Animal with a short broad head ; tentacles distant, with eyes 
on the middle ; proboscis long, retractile. 

Lingual dentition similar to velutina ; teeth single, hamate, 
denticulated; uncini 3 : 1 denticulate, 2 and 3 simple (Fig. 82). 




'Fig. 82. Trichotropis iorealis. ("Warrington). 

Loven places Trichotropis in the same family with Velutina; 
Cancellaria is very closely allied, though it wants both teeth 
and operculum. Mr. Couthouy describes Trichotropis cancellafa 
as having a muzzle like Littorina. 

Distrihution, 14 species. Northern seas. United States, Green- 
land, Melville Island, Behring's Straits, North Britain. 15 — 80 
fathoms. 1 species from Japanese seas (A. Adams). 

Fossil, 1 species. Miocene — . Britain. 

Pyhttla, Lam. Fig- shell. 

Etymology, diminutive of pyrus, a pear. 

Synonyms, Ficula, Sw. Sycotypus, Br., Cassidula, Humph. 
Cochlidium, Gray. 

Type, P. ficus. PI. Y., Fig. 6. 

Shell pear-shaped; spire short; outer lip thin; columella 
smooth ; canal long, open. No operculum in the typical 
species. 

Distribution, 39 species. West Indies, Ceylon, Australia, 
China, Western America. 

Fossil, 32 species. Neocomian — . Europe, India, Chili, Java. 

Pyrula ficus has a broad foot, truncated and horned in front ; 
the mantle forms lobes on the sides, which nearly meet over the 
back of the shell. Chinese seas, in lY — 35 fathoms water. 
(Adams.) 

Sub-genera, Fulgur, Montfort P. perversa. (= Pyrella, Sw. 
P. spirillus.) 

Bapana, Schum. P. bezoar, shell perforated. Operculum 
lamellar, nucleus external. This appears to be a Purpura. 

Myristica. Sw. P. melongena. PI. Y., Fig. V. Operculum 
pointed, curved. 



218 MANUAL OP THE MOLLUSCA. 

FiTSTJS, Lam. Spindle-sliell. 

Synonyms, Colus, Humpli. Leiostoma (bulbiformis). Sw. 
Strepsidura, Sw. 

Type, F. colus. PL Y., Fig. 8. 

Shell fusiform ; spire many-whorled ; canal straight, long ; 
operculum ovate, cuired, nucleus apical. PI. Y., Fig. 9*. 

Distribution, 184 species. World-wide. The typical species 
are sub-tropical. Australia, New Zealand, China, Senegal, 
United States, "Western America, Pacific. 

Fossil, 320 species. Bath oolite? Gault — Eocene — . Britain, &c. 

Sub-genera, Trojphon, Montfort. F. magellanicus, PI. lY., 
Fig. 16. 38 species. Antarctic and Northern seas. British 
coast. 5 — 70 fathoms. Fossil, Chili, Britain. 

Clavella, Sw. (Cyrtulus, Hinds), body- whorl yentricose, sud- 
denly contracted in front ; canal long and straight. Eesembling 
a turbinella, without plaits. 2 species. Marquesas, Panama. 
Fossil, Eocene. F. longsevus (Solander), Barton, &c. 

Chrysodomus, Sw. F. antiquus (yar.). PL Y., Fig. -9. Canal 
short; apex papillary; lingual dentition like buccinum, 12 
species. Spitzbergen, Dayis's Straits, Britain, Mediterranean, 
Kamtschatka, Oregon. Low-water to 100 fathoms. Fossil, 
Pliocene. Britain, Sicily. 

Pusionella, Gray. F. pusio, L. species (== F. nifat, Lam.), 
columella keeled. Operculum, nucleus internal. 7 species ; 
Africa, India. Fossil, Tertiary. France. 

Fusus colosseus and proboscidalis. Lam., are two of the 
largest liying gasteropods. Fusus (^chrysodomus) antiquus, called 
the red- whelk on the coasts of the Channel, and " buckie" in 
Scotland, is extensiyely dredged for the markets, being more 
esteemed than the buccinum. It is the "roaring buckie," in 
which the sound of the sea may always be heard. In the 
Zetland cottages it is suspended horizontally, and used for a 
lamp ; the cayity containing the oil, and the canal the wick. 
(Fleming.) The reyersed yariety (F. contrarius, Sby.) is found 
in the Mediterranean, and on the coast of Spain ; it abounds in 
the pliocene tertiary (crag) of Essex. The fusus deformis, a 
similar species, found off Spitzbergen, is always reyersed. 

Family III. — ^Buccinid^. 

Shell notched in front ; or with the canal abruptly reflected, 
producing a kind of yarix on the front of the shell. 

Animal similar to murex; lingual ribbon long and linear 



GASTEROPODA. 



219 



(Fig. 16), rachidlan teeth single, transverse, dentated in front ; 
uncini single. Carnivorous. 

BucciNUM, L. "WTielk. 

Etymology^ luccina, a trumpet, or triton's-shell. 

Type, B. undatum. PI. Y., Fig. 10. 

Shell few whorled ; whorls ventricose ; aperture large ; canal 
very short, reflected ; operculum lamellar, nucleus external. 
(See Pisania.) 

Distribution, 48 species. Northern and Antarctic seas. Low 
Water to 100 fathoms. (Forbes.) (B. ? clathratum, 136 fathoms, 
off Cape). South Australia. 

Fossil, 130 species, including Ptsama, &c. Gault? — Miocene — 
Britain, France. 




{"ig. 83. Nidamental capsiiles of the Wlielk.* 

The whelk is dredged for the market, or used as hait by 
fishermen ; it may be taken in baskets, baited with dead fish. 
Its nidamental capsules are aggregated in roundish masses, 
which when thrown ashore, and drifted by the wind resemble 
corallines. Each capsule contains five or six young, which, 
when hatched, are like Fig. 83, 6 : a represents the inner side 
of a single capsule, showing the round hole from which the fry 
have escaped. 

Sub-genus, Cominella, Gray. Fx. B. limbosum, purpura 
maculosa, &c. Operculum as in fusus. About 12 species. 

PsEUDOLiVA, Swainson. 

Etymology, named from its resemblance to oliva, in form. 
Synonyms, Sulco-buccinum, D'Orbigny. Gastridium (Grayj 
G. Sowerby. 

* Fig. 83. From a small specimen, on an oyster-shell, in the cabinet of Albany Han • 
cock, Esq. The line at b represents the length of the young shell. 

L 2 



1220 MANUAL OP TKE MOLLTJSCA. 

Type, p. plumbea. PI. Y., Fig. 12. 

Shell globular, thick ; with a deep spiral fiuTow near the 
front of the body-whorl, forming, as in monoceros, a small tooth 
on the outer lip ; spire short, acute ; suture channelled ; inner 
lip callous ; aperture notched in front ; operculum ? Animal 
unknown. 

Distribution, 6 species. Africa and California. 

Fossil, 5 species. Eocene. Britain, Prance, Chili. ' 

? Anolax (Eoissy), Conrad, Lea. 

Etymology, an aulax, without furrow. 

Synonyms, Buccinanops, D'Oroigny. Leiodomus, Sw. Bullia, 
Gray. 

Types, A. gigantea. Lea. Buc. Isevigatum. B. semiplicata, 
PL Y., Pig. 14. 

Shell variable ; like buccinum, pseudoliya, or terebra ; sutures 
enamelled ; inner lip callous. 

Animal without eyes ; foot very broad ; tentacles long and 
slender ; operculum pointed, nucleus apical. 

Distribution 26 species. Brazil, West Africa, Ceylon, Pacific, 
Western America. 

Fossil, 3 species. Eocene — . North America, Prance. 

? Halia, Eisso. 

Etymology, halios, marine. 

Synonym, Priamus, Beck. 

Types, bulla heHcoides (Brocchi). Miocene, Italy. Helix 
priamus (Meuschen). Coast of Guinea ? 

Shell like achatina ; ventricose, smooth ; apex regular, obtuse, 
operculum ? The fossil species occurs with marine shells, and 
sometimes coated by a polyzoon [lepralia). 

Terebea, Lamarck. Auger- shell. 

Synonyms, Acus, Humph. Subula, Bl. Dorsanum, Gray. 

Type, T. maculata. PL Y., Pig. 13. 

Shell long, pointed, many-whorled ; aperture small ; canal 
short ; operculum pointed, nucleus apical. 

Animal blind, or with eyes near the summit of minute 
tentacles. 

Distribution, 109 species, mostly tropical. Mediterranean 
(1 species). India, China, Western America. 

Fossil, 24 species. Eocene — . Britain, Prance, Chili. 



GASTEROPODA. 221 

Eburna, Lamarck. Ivory- shell. 

Etymology^ ehur, ivory. 

Synonym, Latrunculus, Gray. 

Type, E. spirata. PI. Y., Eig. 11. 

Shell umbilicated when young ; inner lip callous, spreading 
and covering the umbilicus of the adult ; operculum pointed, 
nucleus apical. 

Distribution, 9 species. Eed Sea, India, Cape, Japan, China, 
Australia. Solid, smooth shells, which have usually lost their 
epidermis, and are pure white, spotted with dark red; the 
animal is spotted like the shell. 14 fathoms. (Adams.) 

Nassa, Lam. Dog-whelk. 

Etymology, nassa, a basket used for catching fish. 

Synonyms, Desmoulinsia and Northia, Gray. 

Type, N. arcularia. PI. Y., Fig. 15. 

Shell like bucckium ; columellar lip callous, expanded, form- 
ing a tooth-like projection near the anterior canal. Operculum 
ovate, nucleus apical. Lingual teeth arched, pectinated ; uncini, 
with a basal tooth. 

The animal has a broad foot, with diverging horns in front, 
and two little tails behind. N. ohsoleta (Say) lives within the 
influence of fresh water and becomes eroded. N. reticulata, L., 
is common on the English shores at low water, and is called the 
dog- whelk by fishermen. 

JDistrihution, 210 species. Low water — 50 fathoms. "World- 
wide. Arctic, Tropical, and Antarctic Seas. 

Fossil, 19 species. Eocene — . Britain, &c. North America. 

Sub-genus, Oyllene, Gray. C. Oweni, PI. Y., Fig. 17. Outer 
lip with a slight sinus near the canal ; sutures channelled. 
"West Africa, Sooloo Islands, Borneo. Fossil, Miocene, Touraine. 

Cydonassa, Swainson. C. neritea, PI. Y., Fig. IQ. 

Phos, Montfort. 

Etymology, phos, light. 

Synonym, Phinodomus, Sw. 

Type,V. senticosus, PI. Y., Fig. 18. 

Shell like nassa ; cancellated ; outer lip striated internally, 
with a slight sinus near the canal ; columella obliquely grooved. 

The animal has slender tentacles, with the eyes near their 
tips. 

Distribution, 30 species, (Cuming.) Eed Sea, Ceylon, Philip- 
pines, Australia, West America. 



2'22 MANUAL OF THE MOLLUSCA. 

? EINGICULA, Deshayes. 

Etymology, diminutive of ringens, from ringo, to grin. 

Type, E. ringens, PI. Y., Fig. 21. 

Shell minute, ventricose, with a small spire ; aperture notched, 
columella callous, deeply plaited ; outer lip thickened and 
reflected. 

Distribution, 7 species ? Mediterranean, India, Philippines, 
Gallapagos. 

Fossil, 9 species. Miocene — . Britain, France. Ringicula 
is placed with nassa by Dr. Gray and Mr. S. Wood ; it appears 
to us very nearly allied to cinulia =:= avellana, D'Orbigny) in 
tornatellidce. 

PuEPUBA (Adans.), Lam. Purple. 

Type, P. persica, PI. YI., Fig. 1. 

Shell striated, imbricated, or tuberculated ; spire short ; 
aperture large, slightly notched in front ; upper lip much worn 
and flattened. Operculum lamellar, nucleus external. PI. YI., 
Fig. 2. Lingual dentition like murex erinaceus; teeth trans- 
verse, three crested ; uncini small, simple. 

Many of the purpurce produce a fluid which gives a dull 
crimson dye ; it may be obtained by pressing on the operculum. 
F. lapillus abounds on the British coast at low water, amongst 
sea-weed; it is very destructive to mussel-beds. (Fleming.) 

Distribution, 140 species. West Indies, Britain, Africa, India, 
New Zealand, Pacific, Chili, California, Kamtschatka. From 
low water — 25 fathoms. 

Fossil, 40 species. Tertiary — . Britain, France, &c, 

Concholepas, Favan. 0. lepas (Gmelin spocies) PI. YI,, Fig. 3. 
Peru. The only species differs from purpura in the size of its 
aperture and smallness of the spire. 

Cuma (Humphrey) P. angulifera, inner lip with a single 
prominent fold. 

? PuBPUiirN-A (Lycett, 1847), D'Orbigny. 

Shell ventricose, coronated; spire short; aperture large, 
scarcely notched in front. 

Fossil, 9 species. Bath-oolite. Britain, France. The type 
jP. rugosa, somewhat resembles pwyura chocolatum (Duclos), but 
the genus probably belongs to an extinct group. 

Ehizochiltjs, Stp. 1850. 
Example, E. antipathum. Founded on a species of Purpura ? 



GASTEROPODA. 223 

wliicli lives on the antipathes ericoides. Wlien adult they attacli 
themselves, singly or in groups, to the branches of the coral, or 
to each other, by a solid extension of the lips of the shell. The 
aperture becomes closed, with the exception of the respiratory 
canal. 

MoNOCEROS, Lam. 

Etymology, monos, one ; ceras, a horn. 

Synonyms, Acanthina, Fischer. Chorus, Gray. 

Type, M. imbricatum. PI. YI., Fig. 4. (Buc. monoceros, 
Chemn.) 

Shell like purpura ; with a spiral groove on the whorls, end- 
ing in a prominent spine on the outer lip. This genus is retained 
on account of its geographical curiosity ; it consists of species 
of purpura, lagena, turhinella, pseudoliva, &c. 

Distribution, 18 species. West coast of America. 

■Fossil, Tertiary. Chili. 

M. giganteus (chorus) has the canal produced like fusus. M, 
cingulatum is a turhinella, and several species belong more pro- 
perly to lagena. 

Pediculaiiia, Swainson. 

Type, P. sicula. PI. YI., Pig. 5. {Thyreus, Phil.) 

Shell very small, limpet-like ; with a large aperture, channelled 

in front, and a minute, lateral spire. Lingual dentition peculiar ; 

teeth single, hooked, denticulated ; uncini, 3 ; 1 four-cusped, 2, 

3, elongated, three-spined. 

Distribution, 1 species. Sicily, adhering to corals. Closely 

allied to purpura madreporarum, Sby. Chinese Sea. 

EiciNTJLA, Lam. 

Etymology, diminutive of ricinus, the (fruit of the) castor-oil 
plant. 

Example, B. arachno'ides. PL YI. , Fig. 9 ( = murex ricinus, L.). 

Shell thick, tuberculated, or spiny ; aperture contracted by 
callous projections on the lips. Operculum as in purpura. 

Distribution, 34 species. India, China, Philippines, Australia, 
Pacific. 

Fossil, 3 species. Miocene — . France. 

Planaxis, Lam. 

Type, P. sulcata. PI. YI., Fig. 6. 
Synonyms, Quoyia and Leucostoma. 
Shell, turbinated ; aperture notched in front; inner lip callous, 



224 



MAirUAL OF THE MOLLTJSCA. 



channelled behind ; operculum suhsjpiral (quoyia) or semi-OYate. 
PL YI., Fig. 7. 

Distribution, 27 species. West Indies, Eed Sea, Bourbon, 
India, Pacific, and Peru. 

Fossil, Miocene ? 

Small coast shells, resembling periwinkles, with which 
Lamarck placed them. This genus is now generally placed 
among the Littorinidse. 

Magiltjs, Montfort, 1810. 

Synonyms, Campulote, Gruettard, 1759. Leptoconchus, Biippell. 

Type, M. antiquus. PL Y., Pigs. 19, 20. 

Shell, when young, spiral, thin ; aperture channelled in front ; 
adult, prolonged into an irregular tube, solid behind; operculum 
lamellar. 

Distribution, 4 species. Eed Sea, Mauritius. 

The magili live fixed amongst corals, and grow upwards with 
the growth of the zoophytes in which they become immersed ; 
they fill the cavity of the tube with solid shell as they advance. 

Cassis, Lam. Helmet-shell. 

Synonyms, Bezoardica, Schum. Levenia, Gray. Cyprsecassis, 
Stutch. 

Type, C. flammea. PL YL, Pig. 14. 
Shell ventricose, with irregular varices ; spire 
short ; aperture long, outer lip reflected, denticu- 
lated ; inner lip spread over the body-whorl ; 
canal sharply recurved. Operculum small, elon- 
gated; nucleus in the middle of the straight 
inner edge (Fig. 84). Lingual teeth 3, 1, 3, as 
in Fig. 85. 

The spiny buccal plates of Cassis have been 
mistaken by Gray and Adams for the teeth, which 
in this genus, and also in Triton, are very minute 
and transparent. 




Fig. 84 
of Cassis. 



Operc. 




Fig. 85. Cassis sdburon. (Original). 

Distribution, 37 species. Tropical seas; in shallow water. 
"West Indies, Mediterranean, Africa, China, Japan, Australia, 
New Zealand, Pacific, Mexico. 



GASTEROPODA. 225 

Fossili 36 species. Eocene — . Chili, France. 

The queen -conch (C. madagascariensis) and other large 
species are used in the manufacture of shell cameos, p. 38. The 
periodic mouths {varices) which are very prominent, are not 
absorbed internally as the animal grows. 

Okiscia, Sowerby. 

Etymology^ oniecus^ a wood-louse. 

Synonym^ Morum, Bolten. 

Type^ 0. oniscus ; 0. cancellata, PL YI., Fig. 15. 

Shell with a short spire and a long narrow aperture, slightly 
truncated in front ; outer lip thickened, denticulated ; inner lip 
granulated. 

Distribution^ 9 species. West Indies, China, G-allapagos, 
United States. (20 fathoms). 

Fossil^ 3 species. Miocene. United States, Domingo. 

Cassidabia, Lam, 

Etymology y cassida^ a helmet. 

Synonyms^ Morio, Montfort. Sconsia, Gray, 

Type, C. echinophora. PL Yl., Fig. 13. 

Shell ventricose ; canal produced, rather bent. No operculum. 

Distribution, 6 species. Mediterranean. 

Fossili 10 species. Eocene — . Britain, France, &o. 

Bachybathron-, Gaskoin, 

Shell small, oblong, striated with lines of growth; spire 
small, depressed, with channelled suture ; aperture with callous 
denticulated lips, like Cypraa^ 

Distrihution, 3 species. 




Fig. 86. DoUum perdix. (Original). 

DoLiuM, Lam. The Tun. 
Type, U. galea. PL YL, Fig. 12. 

Shell ventricose, spirally furrowed ; spire small ; aperture 
very large ; outer lip crenated. Ko operculum. Teeth 3, 1, 3. 
Fig. 86. The genus Macgillivrayia, formerly assigned to the 
Atlantidse, belongs here. It comprises the larva forms of several 
species of Dolium. 

L 3 



226 MANUAL OF THE MOLLrSCA. 

Distrihution, 14 species. Mediterranean, Ceylon, China, Aus- 
tralia, Pacific. 



Fossil, 7 species. (? Chalk. Britain). Tertiary. South Europo. 

Sub-genus, Malea, Yalenc. (D. personatum), outer lip 

thickened and denticulated ; inner lip with callous prominences. 

Haepa, Lam. Harp-shell. 

Type, H. ventricosa. PI. VI., Fig. 11. (= Buc. harpa, L.) 

Shell Yentricose, with numerous ribs, at regular intervals ; 
spire small ; aperture large, notched in front. No operculum. 

The animal has a very large foot, with the front crescent- 
shaped, and divided by deep lateral fissures from the posterior 
part, which is said to separate spontaneously when the animal 
is irritated. Mostly obtained from deep water and soft bottoms. 

Distribution, 12 species. Mauritius, Ceylon, Philippines. 
Pacific. 

Fossil, 4 species. Eocene—. Erance. 

COLTTMBELLA, Lam. 

Etymology, diminutive of columba, a dove. 

Type, C. mercatoria. PI. VL, Eig. 10. 

Shell small, with a long narrow aperture ; outer lip thickened 
(especially in the middle), dentated ; inner lip crenulated. 
Operculum very small, lamellar. 

Distribution, 205 species. Sub-tropical. West Indies, Medi- 
terranean, India, Gallapagoa, California. Small, prettily- 

• D. perdix, L. species. | natural size (after QuojO- Vanicoro, Pacific. The 
I roboBciff is exserted, and the siphon recurved over the front of the shell. 



GASTEHOPODA. 227 

marked shells ; living in shallow water, on sandy flats, or 

congregating about stones. (Adams.) 

Fossil) 8 species. Tertiary. (The British species are pisanice.) 
Sub-genuSi ColumbelUna^ B'Orbigny. 4 species. Cretaceous. 

France, India. 

Oliva, Lam. Olive, rice-shell. 

Type, 0. porphyria. PL YI., Fig. 16. 
Synonym^ Strephona, Brown. 

Shell cylindrical, polished; spire very short, suture channelled; 
aper'ure long, narrow, notched in front; columella callous, 
striated obliquely; body-whorl furrowed near the base. No 
operculum in the typical species. 

Animal with a very large foot, in which the shell is half 
immersed; mantle lobes large, meeting over the back of the 
shell, and giving off filaments which lie in the suture and furrow. 
The eyes are placed near the tips of the tentacles. 

The ohves are very active animals, and can turn over, when 
laid on their back ; near low water they may be seen gliding 
about or burying in the sands as the tide retires ; they may be 
taken with animal baits attached to lines. They range down- 
wards to 25 fathoms. 

Distribution, 120 species. Sub-tropical, "West and East 
America. West Africa, India, China, Pacific. 

Fossil, 20 species. Eocene — . Britain, Prance, &c. 
Sub-genera. Olivella, Sw. 0. jaspidea, PL YL, Pig. 19. 
Animal with small, acute frontal lobes. Operculum 
nucleus sub-apical. 
Scaphula, Sw. = OlivanciLlaria, D'Orbigny, PL YI., 
Pig. 18, 
Frontal lobes large, rounded, operculate. 

Agaronia, Gray. 0. hiatula, PL YL, Pig. 17. 
No eyes or tentacles. Frontal lobes moderate, acute. 

Ancillaria, Lam. 

Etymology, ancilla, a maiden. 

Types, A. subulata, PL YL, Fig. 20. A. glabrata, PL YL, 
Fig. 21. 

Shell like oliva; spire produced, and entirely covered with 
shining enamel. Operculum minute, thin, pointed. Lingual 
teeth pectinated. Uncini simple, hooked. 

Animal like oliva ; said to use its mantle-lobes for swimming. 
(lyOrbigny.) In A. glabrata, a space resembling an umbilicus, 
is left between the callous inner lip and the body-whorl. 




228 MANITAX OF THE MOLLTTSCA. 

Distribution, 23 species. Eed Sea, India, Madagascar, Aus- 
tralia, Pacific. 

Fossil, 21 species. Eocene — •. Britain, France, &c. 

Family IV. — Conidje, Cones. 

Shell inversely conical; aperture long and 
narrow ; outer lip notched at or near the suture j 
operculum minute, lamellar. 

Animal foot oblong, truncated in front ; with a 
conspicuous (aquiferous ?) pore in the middle. Head 
produced. Tentacles far apart. Eyes on the ten* 
tacles. Gills 2. Lingual teeth {uncini?) in pairs, 
Fie 88.* elongate, subulate, or hastate. 

CoiirD"s, L, Cone-sheU 

Types, C. marmoreus, PI. YII., Eig. 1. C. geographicus, 
antediluyianus, &c. 

Shell conical, tapering regularly ; spire short, many-whorled ; 
columella smooth, truncated in front ; outer lip notched at the 
suture ; operculum pointed, nucleus apical. 

Distribution, 371 species. All tropical seas. 

Fossil, 84 species. Chalk — . Britain, France, India, Java, &c. 

The cones range northward as far as the Mediterranean, and 
southward to the Cape ; but are most abundant and varied in 
equatorial seas. They inhabit fissures and holes of rocks, and 
the warm and shallow pools inside coral-reefs, ranging from 
low water to 30 and 40 fathoms ; they move slowly, and some- 
times ( 0. aulicus) bite when handled ; they are all predatory. 
(Adams.) 

Sub-genus Conorhis, Sw. C, dormitor, PL YII., Fig- 2« 
Eocene — . Britain, France. 

Pleueotoma, Lam. 

Etymology, pleura, the side, and toma, a notch. 

Synonym, Turris, Humphrey. 

Types, P. Babylonica, PI. YIL, Fig. 3. P. mitrseformis, &c. 

Shell fusiform, spire elevated ; canal long and straight ; outer 
lip with a deep slit near the suture. Operculum pointed, nucleus 
apical. 

Distribution, 430 species. World-wide. Grreenland, Britain, 
17 ; Mediterranean, 19 ; Africa^ 15 ; Eed Sea and India, 6 ; 
China, 90; Australia, 15 ; Pacific, ? West America, 62 ; West 

* Fig. 88. Lingual teeth of Bela turricula (after Lovea). 



GASTEHOPOBA. 229 

Indies and Brazil, 20. The typical species about 20 (China, 16 ; 
West America, 4). Low water to 100 fathoms. 

Fossil, 378 species. Chalk — . Britain, France, &c. Chili. 

Suh-genera, BriUia, Gray. D. umbilicata, canal short. 

Clavatula, Lam., canal short, operculum pointed, nucleus in 
the middle of the inner edge. C. mitra, PI. VII., Fig. 4. 

Tomellaf Sw., canal long; inner lip callous near suture. T. 
lineata. 

? CUonella, Gray. C. sinuataj Born species. (== P* buccinoides), 
freshwaters, Africa. 

Mangelia^ Leach (not Peeve). Apertural slit at the suture 5 
no operculum, M. tseniata, PI. YIL, Pig. 5. Greenland, Britain, 
Mediterranean . 

Bela, Leach. Operculum nucleus apical. B. turricula, PL 
TIL, Pig. 6. 

Defranda^ Millet,* no operculum. D, linearis, PI. YIL, 
Pig. 7. 

? Lachesis, Eisso, L. minima, PL YIL, Pig. 8, apex mam- 
millated ; operculum claw - shaped. Mediterranean, South 
Britain, Japan. In shallow water. 

DapJmella, Hinds. D. marmorata. New Guinea. (Buc. 
junceum. L. clay). 

Borsonia, Edwards. 2 species recent ; tropical seas. Fossil^ 
6 species. Tertiary. Europe. 

ClTHARA, Schumacher. 

Etymology, citliara, a guitar. 

Synonym, Mangelia, Peeve (not Leach). 

Type, cancellaria citharella. Lam. (cithara striata, Schum.). 

Shell fusiform, polished, ornamented with regular longitudinal 
ribs; aperture linear, truncated in front, slightly notched 
behind; outor lip margined, denticulated within; inner lip 
finely striated. Operculum. 

Bistrihution, above 50 species of this pretty little genus were 
discovered by Mr. Cuming in the Philippine Islands. 

Family Y. — YoLTTTroiE. 

Shell turreted, or convolute ; aperture notched in front J 
columella obliquely plaited. No operculum. 

Animal with, a recurved siphon ; foot very large, partly hiding 
the shell ; mantle often lobed and reflected over the shell ; eyes 

* According to Mr. S. Hanley, Defrancia is synonymoufl with Mangelia. 



230 



MANUAL OF THE MOLLUSCA. 



on the tentacles, or near their base. 
rachis, toothed; pleurm^ unarmed. 



Lingual ribbon linear; 




Fig. 89.» 

YoLrTA. L. Volute. 

Tijpe, Y. musica, PI. YII., Fig. 9. 

Synonyms, Cymbiola, Harpula, Sw. Yolutella, D'Orbigny. 
Scapha, &c., Gray. 

Shell ventricose, thick; spire short, apex mammillated ; 
aperture large, deeply notched in front ; colu- 
mella with several plaits. V. musica and a few 
others have a small operculum. 

Animal eyes on lobes at the base of the ten- 
tacles ; siphon with a lobe on each side, at its 
base ; lingual teeth 3-cusped (Fig. 90). 

V. vespertilio and hebrcea fill the nuclei of 
their spires with solid shell. F. hrasiliana 
forms nidamental capsules 3 inches long. 
(D'Orbigny.) In F. angulata the mantle is 
produced into a lobe on the left side, and over- 
laps the shell. 

Distribution, 70 species. West Indies, Cape 
Horn, West Africa, Australia, Java, Chili. 

Fossil, 80 species. Chalk — . India, Britain, France, &c. 
Suh-genera, Volutilithes, Sw. Spire pointed, many-whorled, 
columella plaits indistinct. F. sjpinosus, PL YII., Fig. 10. 

Living, 1 species (F. ahyssicola), dredged at 132 fathoms; off 
the Cape. (Adams.) 

Fossily Eocene. Britain, Paris. 

Scaphella, Sw. Fusiform, smooth. 
Example, Y. magellanica. 

* Fig. 89. V. undulata, Lam. f Australia. (From Quoy and daimard.) 




Fig. 90. Valuta 
(Wilton). 



GASTEROPODA. 231 

Fossil, y. Lamberti, Crag, Suffolk, 

Melo, Brod. Large, oyal ; spire short. 
Type, M. diadema, PI. YII., Fig. 11. New Guinea, 8 species. 



Cymba, Broderip. Boat- shell. 

Synonym, Tetus (Adans.), Gray. 

Type, 0. proboscidalis, PI. VII., Pig. 12, 
and Pig. 91 (=== V. cymbium, L.). 

Shell like yoluta ,' nucleus large and 
globular; whorls few, angular, forming a 
flat ledge round the nucleus, 

The foot of the animal is very large, and 
deposits a thin enamel over the under side 
of the shell. It is oyo-viviparous, and 
the young animal is very large when born j 
the nucleus becomes partly concealed by the 
growth of the shell. 

Distribution, 10 species. West Africa, 
Lisbon. 




^Fig. 91. Cymha, 



MiTEA, Lam. Mitre-sheU. 

Synonyms, Turris, Montfort, Zierliana, Gray. Tiara, Sw. 

Types, M. episcopalis, PL YII., Pig. 13. M. vulpecula 
Pig. 14. 

Shell fusiform, thick ; spire elevated, acute ; aperture small, 
notched in front ; columella obliquely plaited ', operculum very 
small. 

The animal has a very long proboscis ; it emits a purple 
liquid, having a nauseous odour, when irritated. The eyes are 
placed on the tentacles, or at their base. Eange, from low 
water to 15 fathoms, more rarelv in 15 — 80 fathoms. 

Bistrihution, 420 species. Philippines, India, Eed Sea, 
Mediterranean, West Africa, Greenland (1 species), Pacific, 
West America. The extra-tropical species are minute. M. 
Greenlandica and M. Cornea (Mediterranean species) are found 
together in the latest British Tertiaries. (Forbes.) 

Fossil, 90 species. Chalk—. India, Britain, Prance, &c. 

Sub-genera. Imbricaria, Schum, (conoelis, Sw.) 

Shell cone-shaped. I. conica, PI. TIL, Pig. 15. 

Cylindra, Schum. (Mitrella, Sw.) 

Shell olive-shaped. C. crenulata, PI. VIL, Pig. 16. 



232 MANtJAL OF THE MOLLtTSCA. 

YoLVAniAj Lam. 

Etymology^ voiva^ a wrapper. 
Type, V. buUoides, PI. YII., Fig. 17. 

Shell cylindrical, convolute : spire tointite ; aperture long and 
narrow ; columella with, three oblique plaits in front. 
Distribution, 29 species, tropical seas. 
Fossil, 5 ? species. Eocene. Britain, Prance. 

Mabginiella, Lam. 

Etymology^ diminutive of margo, a rim. 

Synonyms, Porcellana (Adans.)^ Grray. Persicula, Schum. 

Types, M. nubeculata, PI. YIL, Pig. 18. M. persicula, 
Vig. 19. 

Shell smooth, bright; spire short or concealed; aperture 
truncated in front ; columella plaited ; outer lip (of adult) with 
a thickened margin. 

Animal similar to cypreea. 

Distribution, 139 species. Tropical, West Indies, Brazil, 
Mediterranean (1 small species) j West Africa, China, Australia. 

Fossil, 30 species. Eocene — . Prance, &c. 

Sub-genus, Hyalina, Schum. Outer lip scarcely thickened. 

Type, voluta pallida, Montfort, West Indies. 

Family VI.— Cype^id^. Cowries. 

Shell convolute, enamelled ; spire concealed ; aperture narrow, 
channelled at each end ; outer lip (of adult) thickened, inflected. 
No operculum. 

Animal with a broad foot) truncated in front ; mantle expanded 
on each, side, forming lobes, which, meet over the back of the 
shell ; these lobes are usually ornamented with tentacular fila- 
ments ; eyes on the middle of the tentacles or near their base ; 
branchial plume single. Lingual ribbon long, partly contained 
in the visceral cavity ; racMs 1 toothed; uncini 3. In Ovulum 
the teeth are 2. 1. 2. the outermost broad, with pectinated 
margins. Loven describes the Cyprseidse as having a short, non- 
retractile muzzle, and places them between the Naticidw and 
Lamellaria. The cowries inhabit shallow water, near shore, 
feeding on zoophytes. 

Ctprjea, L. Cowry. 

Etymology, Cypris, a name of Yenus. 

Types, C. tigris, C. mauritiana PI. YII., Fig. 20. 



GASTEEOPODA. 



233 




Fig. 92. CyprcBa, 
young.* 




Fig. 93. 
Trivia.^ 



Shell ventricose, convolute, covered witli shining enamel ; 
spire concealed ; aperture long and 
narrow, with a short canal at each 
end ; inner lip crenulated ; outer lip 
inflected and crenulated (lingual 
uncini similar). 

The young shell has a thin and 
sharp outer lip, a prominent spire, 
and is covered with a thin epidermis 
(Fig. 92). When full-grown the 
mantle lobes expand on each side, 
and deposit a shining enamel over 
the whole shell, by which the spire 
is entirely concealed. There is usually 
a line of paler colour, which indicates 
where the mantle lobes met. Cyprcea 
annulus is used by the Asiatic Islanders to adorn their 
dress, to weight their fishing-nets, and for barter. 
Specimens of it were found by Dr. Layard in the ruins of 
Nimroud. The money- cowry [Q. moneta) is also a native of the 
Pacific and Eastern seas ; many tons weight of this little shell 
are annually imported into this country, and again exported 
for barter with the native tribes of Western Africa ; in the year 
1848 sixty tons of the money- cowry were imported into Liver- 
pool. Mr. Adams observed the pteropodous fry of C. annulus, 
at Singapore, adhering in masses to the mantle of the parent, 
or swimming in rapid gyrations, or with abrupt jerking move- 
ments by means of their cephalic fins. 

Distribution, 150 species. In all warm seas (except east 
coast South America ?), but most abundant in those of the old 
world. On reefs and under rocks at low water. 

Fossil, 84 species. Chalk — . India, Britain, France, &c. 
Sub-genera. Cyprovula, Grray. C. Capensis, PI. YII., Fig. 21. 
Apertural plaits continued regularly over the margin of the 
caiial. 

Luponia, Gray. C. algoensis, PL YII., Fig. 22. Inner lip 
irregularly plaited in front. 

Trivia, Gray. C. europsea, PL YII., Fig. 23; Fig. 93, and 
15, B. Small shells with strise extending over the back. 
{Uncini: 1st denticulate, 2, 3, simple.) 



* Fig 92. O/preea testudinaria, L., young, China. 

t Fig. 93. Trivia Europcecf., Mont. From the '• British ^ollusca," by Messrs. Forbea 
and Hanley. 



234 MANUAL OF THE MOLLIJSCA. 

Distribution, 30 species. Greenland, Britain, West Indies, 
Cape, Australia, Pacific, West America. 

Eeato, Eisso. 

Etymology, Erato, the muse of love -songs and mimicry. 
Type, E. Isevis, PL VII., Fig. 24. 

Shell minute ; like marginella ; lips minutely crenulated. 
Animal like trivia. 

Distribution, 1 1 species. Britain, Mediterranean, West Indies, 
China. 
Fossil, 2 species. Miocene — . Prance, Britain (Crag). 

Oyulitm:, Lam. 

Etymology, diminutive of ovum, an egg. 

Synonym, Amphiceras, Gronov. 

Types, 0. Ovum, PI. YIL, Pig. 25. 0. gibbosa and verrucosa. 

Shell like cyproea ; inner lip smooth. 

Distribution, 36 species. Warm seas. West Indies, Britain, 
Mediterranean, China, West America. 

Fossil, 11 species. Eocene — . Prance, &c. 

Sub-genus. Calpurna, Leach. 0. volva ("the weaver's 
shuttle "). Aperture produced into a long canal at each end. 
Poot narrow, adapted for walking on the round stems of the 
gorgonice, &c., on which it feeds. C. patula inhabits the south 
coast of Britain, it is very thin, and has a sharp outer lip. 

Calpurnus, Montfort (name) = Ovulum verrucosum. 

Volva (Fleming) = Ovulum patulum [Calpurna, Leach). 

Badius (Montfort) Schum. = Ovulum volva 

Section B. Holostomata. Sea-Snails. 

Shell spiral or limpet-shaped ; rarely tubular or multivalve : 
margin of the aperture entire; operculum, horny or shelly, 
usually spiral. 

Animal with a short non -retractile muzzle ; respiratory siphon 
wanting, or formed by a lobe developed from the neck (Fig. 68), 
gills pectinated or plume -like, placed obliquely across the back, 
or attached to the right side of the neck ; neck and sides fre- 
quently ornamented with lappets and tentacular filaments. 
Marine or fresh-water. Mostly phytophagous.* 

» These "sections" are not very satisfactory, but they are better than any others 
yet proposed, and they are convenient on account of the great extent of the order 
proso-branchiata. Natica and scalaria have a retractile proboscis. Pirena haa a 
notched aperture, and aporrhais, a canal. 



GASTEROPODA. 

Family I. — ^Naticid^. 



235 



Shell globular, few-wh.orled ; spire, small, obtuse ; aperture 
eemi -lunar ; lip acute ; pillar often callous. 




umbilicus large, with 
operculum sub-spiral. 




rig. 95. Natica* 



Fig. 94. Natica monilif era ("Wilton). 

Animal with a long retractile proboscis ; lingual ribbon linear ; 
rachis 1 toothed ; uncini 3 (as in Eig. 94) ; foot very large ; 
mantle-lobes largely deYeloped, hiding more or less of the shell. 
Species all marine. 

Natica (Adans.), Lamarck. 

Synonym, Mamilla, Schm. Cepatia, Gray. Nacca, Eisso. 

Type, N. canrena, PI. YIII., Fig. 1. 

Shell thick, smooth ; inner lip callous ; 
a spiral callus ; epidermis thin, polished ; 

Animal blind ; tentacles connate 
with a head veil ; front of the large 
foot provided with a fold [mentv^m), 
reflected upon and protecting the head ; 
operculigeroiis lobe large, covering 
part of the shell ; jaws horny; lingual 
ribbon short ; branchial plume single. 

The coloured markings of the naticse are very indestructible ; 
they are frequently preserved on fossils. The naticoe frequent 
sandy and gravelly bottoms, ranging from low water to 90 
fathoms (Forbes). They are carnivorous, feeding on the smaller 
bivalves (Gould), and are themselves devoured by the cod and 
haddock. Their eggs are agglutiaated into a broad and short 
spiral band, very slightly attached, and resting free on the 
sands. 

Distribution, 197 species. Arctic seas, Britain, Mediterranean, 
Caspian, India, Australia, China, Panama, "West Indies. 

Fossil, 260 species. Devonian — . South America, North 
America, Europe, India. 

Suh-genera. Naticopsis, M'Coy, N. Phillipsii. Shell imper- 
forate ; inner lip very thick, spreading ; operculum shelly 
(British Museum), Carb. limestone, 7 species. 

* Fig. 95. Natica Alderi, Forbes. From an, original drawing, cooamunioated by 
Joshua Alder, Esq 



236 MANUAL OF THE MOLLUSCA. 

Operculum, horny. 

Neverita, Bisso. N. Alderi. Eig. 95. 

Lunatia, Gray. N. Ampullaria. Perforation simple ; epider- 
mis dull, olivaceous. Northern seas. 

Globulus, J. Sby. (Ampulina, Deshayesnot Bl.) N. Sigaretina. 
PI. YIII., Pig. 2. Umbilicus narrow (rimate), lined by a thin 
callus. 

Fossil, Eocene. Britain, Paris. 

Folinices, Montfort (naticella, Guild.), N. mammilla. Shell 
oblong ; callus very large, filling the umbilicus. 

Cernina, Gray, N. fluctuata. PL YIII., Pig. 3. Globular, 
imperforate ; inner lip callous, covering part of the body-whorl. 

Naticella, Miiller. 19 species. 

Fossil, Trias, S. Cassian. 

Deshayesia, Eaulin 

Miocene, Prance. Some additional species have been found 
with a similar oblique aperture and corrugated inner lip. 
Baron Eyckholt has described a species {D. Raulini), from the 
Devonian, Belgium. The relation of the genus is uncertain. 

Naticella, Miinster. 

This genus, abounding in the Trias of St. Cassian, has been 
referred to Natica by D'Orbigny. A characteristic species 
occurs in the green-sand of Blackdown, and has been named 
Natica carinata, J. Sby. (Narica, D'Orbigny.) It is exactly 
intermediate between Narica (p. 23*7) and Fossarus (p. 253), and 
appears to form with them a little group nearly related to 
Lacuna (p. 255). 

SiGAEETirs (Adans.), Lamarck. 

Synonyms, Cryptostoma, Bl. Stomatia, Browne. 

Type, S. haliotoides. PL YIII., Pig. 4. 

Shell striated ; ear-shaped ; spire minute : aperture very wide, 
oblique (not pearly) ; operculum minute, horny, sub-spiral. 

The flat species are entirely concealed by the mantle when 
living ; the convex shells only partially, and they have a 
yellowish epidermis. The anterior foot lobe {mentum) is enor- 
mously developed. 

Distrihution, 31 species. West Indies, India, China, Peru. 

Fossil, 10 species. Eocene — . Britain, Prance, South America. 

Sub-genus. Naticina, Gray. N. papilla, PL YIII., Pig. 3. 
Shell ventricose, thin, perforated. West Indies, Eed Sea, China, 
North Australia, Tasmania. Eocene, Paris. 



GASTEROPODA. 237 

Lamellaeia, Montagu. 

Etymology f lamella^ a thin plate. 

Synonyms, Marsenia, Leach. Coriocella, Bl. 

Type, L. perspicua. PI. YIII., Fig. 6. 

Shell ear- shaped ; thin, pellucid, fragile ; spire very small ; 
aperture large, patulous ; inner lip receding. No operculum. 

Animal much larger than the shell, which is entirely con- 
cealed by the reflected margins of the mantle ; mantle non- 
retractile, notched in front; eyes at the outer bases of the 
tentacles. Lingual uncini 3, similar ; or one very large. 

Distribution, 10 species. Norway, Britain, Mediterranean, 
New Zealand, Philippines. 

Fossil, 2 species. Pliocene — . Britain (Crag). 

Namca, Eecluz. 

Synonyms, Yanicoro, Quoy. Merria, Gray. Leucotis, Sw. 

Type, N. cancellata. PI. YIIL, Fig. 8. 

Shell thin, white, with a velvety epidermis ; ribbed irregularly 
and spirally striated ; axis perforated ; operculum very small, 
thin. 

Animal eyes at the outer base of the tentacles; foot with 
wing-like lobes. 

Distribution, 26 species. West Indies, Nicobar, Yanikoro, 
Pacific. 

Fossil. 4 species, Gault — . (D'Orbigny.) Britain, France. 

YELTrriNA, Fleming. 

Etymology, velutinus, velvety (from veil us, a fleece). 
Type, Y. laevigata. PL YIIL, Fig. Y. 




Fig. 96. Velutina laevigata (Warington). 

Shell thin, with a velvety epidermis ; spire small ; suture 
deep; aperture very large, rounded; peristome continuous, 
thin. No operculum. 

Animal with a large oblong foot; margin of tne mantle 
developed all round, and more or less reflected over the sheU ; 
gills 2 ; head broad ; tentacles subulate, blunt, far apart ; eyes 
on prominences at their outer bases. Carnivorous. Lingual 
dentition (Fig. 96). It resembles that of trivia (Fig. 15, B). 



238 MANUAL OF THE MOLLUSCA. 

Distribution, 4 species. Britain, Norway, North. America, 
Icy Sea to Kamtscliatka. 

Fossil, 3 species. Pliocene—. Britain. 

8uh-genu8. Otina (Grray). V. otis. 

Shell minute, ear-shaped. 

Animal with a simple mantle, and very short tentacles. 
West and south-west British coast ; inhabiting chinks of rocks, 
between tide-marks. (Forbes.) 

Velutina inhabits the laminarian zone, and ranges to 40 
fathoms. V. Icevigata is sometimes brought in on the Jfishermen's 
lines (off Northumberland), generally adhering to Alcyonium 
digitatum (Alder). Dr. Gould obtained it from the stomach of 
fishes. 

CrYPtocella. H. and A. Adams, 1853. 

Shell thin, pellucid, calcareous ; spire small ; aperture large. 

Family II — Pyeajiidellid^. 

Shell spiral turreted ; nucleus minute, sinistral ; aperture 
small ; columella sometimes with one or more prominent plaits ; 
operculum horny, imbricated, nucleus internal. 

Animal with broad, ear-shaped tentacles, often connate; 
eyes behind the tentacles at their bases ; proboscis retractile j 
foot truncated in front ; tongue unarmed. Species all marine. 
They are very numerous in the Japanese seas. 

Several genera of fossil shells are provisionally placed in 
this order, from their resemblance to eulima and chemnifzia.* 
Tornatella, usually placed in or near this family, is opistho" 
branchiate. 

Pyeamidella, Lam. 

Etymology, diminutive of pyramis, a pyramid. 

Synonyms, Obeliscus. Humphrey. (P. dolabrata. PI. VIII., 
Fig. 11.) Syrnola, Adams, 1860. 

Type, P. auris-cati. PI. YIII., Fig. 10. 

Shell slender, pointed, with numerous plaited or level whorls ; 
apex sinistral ; columella with several plaits ; lip sometimes 
furrowed internally ; operculum indented on the inner side to 
adapt it to the columellar plaits. The shell of the typical 
pyramidellse bears some resemblance to cancellaria. 

* " The Pyramidellid<B present subjects of much interest to the student of extinct 
mollusca ; numerous forms, bearing all the aspect of being members of this family, 
occur among the fossils of even the oldest stratified rocks. Many of them are gigantic 
compared with existing species, and the group, as a whole, may be regarded rather as 
appertaining to past ages than the present epoch."— /^or6es. 



GASTEEOPODA. 239 

Bistrihution, 111 species. "West Indies, Mauritius, Australia. 
Fosaily 12 species. Chalk — . Prance, Britain. 

Odostomia, Fleming, 1824. 

Etymology, odous, a tooth, and* stoma, mouth. 

Type, 0. plicata. PL VIII. , Pig. 12. 

Shell subulate or oyate, smooth; apex sinistral; aperture 
ovate ; peristome not continuous ; columella with a single 
tooth-like fold; lip thin; operculum horny, indented on the 
inner side. 

Bistrihution, ? species. Britain, Mediterranean, Eed Sea, 
Australia. 

Fossil, 15 species ? Eocene — . Britain, Prance. 

Very minute and smooth shells, having the habit of rissoce, 
and like them sometimes found in brackish water. They range 
from low water to 40 fathoms. The animal is undistinguishable 
from chemnitzia. 

Chemnitzia, D'Orbigny. 

Etymology, named in honour of Chemnitz, a distinguished 
conchologist of Nuremburg, who published seven volumes in 
continuation of Martini's " Conchylien-cahinet,^^ 1780-95. 

Synonyms, Turbonilla, Eisso. Parthenia, Lowe. Pyramis and 
Jaminea, Br. Monoptigma, Lea, part. Amoura, MoUer. 

Type, C. elegantissima. PL VIIL, Pig. 13. 

Shell slender, elongated, many-whorled ; whorls plaited ; 
apex sinistral ; aperture simple ; ovate ; peristome incomplete ; 
operculum horny, sub-spiral. 

Animal head very short, furnished with a long, retractile 
proboscis; tentacles triangular; eyes immersed at the inner 
angles of the tentacles ; foot truncated in front, with a distinct 
mentum. 

Bistrihution, 32 species. Britain (4 species), Norway, Medi- 
terranean. Probably world-wide. Eange from low water to 
90 fathoms. 

Fossil, 240 species. Silurian — . Britain, Prance, &c. 

The *'melani8D" of the secondary rocks are provisionally 
referred to this genus. Those of the palaeozoic strata to 
loxonema. 

Sub-genera. Eulimella, Porbes. E. sciUse, Scacchi. 4 British 
species. Shell smooth and polished ; columella simple ; apex 
sinistral. 

Stylopsis (Adams, 1860) much resembles and is probably 
synonymous with this sub-genus. 



240 MANUAL OF THE MOLLTJSCA. 

EtJLiMA, Eisso, 1826. 

Etymology^ eulimia, ravenous hunger 

Synonym, Pasithea, Lea. 

Type, E. polita. PI. YIII., Fig. 14. 

Shell small, white, and polished; slender, elongated with 
numerous level whorls ; obscurely marked on one side by a 
series of periodic mouths, which form prominent ribs internally ; 
apex acute ; aperture oval, pointed above ; outer lip thickened 
internally ; inner lip reflected over the pillar ; operculum 
horny, sub-spiral. 

Animal tentacles subulate, close, with the eyes immersed at 
their posterior bases ; proboscis long, retractile ; foot truncated 
in front, mentum bilobed ; operculum lobe winged on each 
side ; branchial plume single ; mantle with a rudimentary 
siphonal fold. 

The eulimse creep with the foot much in advance of the head, 
which is usually concealed within the aperture, the tentacles 
only protruding. (Forbes.) 

Distribution, 49 species. Britain, Mediterranean, India, 
Australia, Pacific. In 5 — 90 fathoms water. 

Fossil, 40 species. Carb. ? — . Britain, France, &c. 

Sub-genus. Niso, Eisso (= Bonellia, Deshayes). N. tere- 
bellatus. Lam. species. Axis perforated. 

Fossil, 3 species. Eocene — . Paris. 

Distribution, 5 species. China, West America. (Cuming.) 

MoNOPTiGMA, Lea. 

Synonyms, Melanioides, Lea = M. striata. Gray (name only). 

Shell like Chemnitzia, rather fusiform, spirally grooved ; 
columella slightly folded, with a sinus at the base. 

Distribution, 12 species. Indo-Pacific. 

Menestho, Moller (Turbo albulus, Fabr. Greenland) v. 
Chemnitzia. 

AcLis, Loven. 

Etymology, A, without, hleis, a projection. 

Synonym, Alvania, Leach (not Eisso). 

Type, A. supranitida. Wood. A. ascaris, Turt. PL IX., 
Fig. 4. 

Shell minute, like turritdla ; spirally striated ; aperture oval ; 
outer lip prominent ; axis slightly rimate ; operculate ; apex 
sinistral. 



GASTEEOPODA. 241 

Animal with a long retractile proboscis ; tentacles close' 
together, slender, inflated at the tij)S ; eyes immersed at the 
bases of the tentacles ; operculum lobe ample, unsymmetrical ; 
foot truncated in front. Eanges to 80 fathoms water. 5 British 
species, Norway. 

Fossil. ? species. Pliocene — . Britain (Crag). 

Sttloptygma, Adams. 1860. 

Shell pupiform, semi-transparent; with slightly convex whorls. 
Aperture sub -quadrate. 

Mtonia, Adams. 

Shell ovate, turreted ; white, thin, with slightly convex 
whorls. Aperture oblong. 

Letjcotina, Adams. 

Shell like last, but with last whorl ventricose ; with minute 
dots. 

Stilifee,, Brod. 

Example^ S. astericola. PL YIIL, Pig. 15. 

Synonym, Stylina, Pleming. 

Shell hyaline, globular or subulate, apex tapering, styliform, 
nucleus sinistral. 

Animal with slender, cylindrical tentacles, and small sessile 
eyes at their outer bases ; mantle thick, reflected over the last 
whorls of the shell ; foot large, with a frontal lobe. Branchial 
plume single. Attached to the spines of sea-urchins, or immersed 
in living star-fishes and corals. 

Distribution^ 16 species. West Indies, Britain, Philippines, 
Gallapagos, Pacific. 

LoxoNEMA, Phillips. 

Etymology^ loxos^ oblique, and nema, thread ; in allusion to 
the striated surface of many species. 

Type, L. sinuata, U. Devonian, Petherwin. 

Shell elongated, many-whorled ; aperture simple, attenuated 
above, effused below, with a sigmoidal edge to the outer lip. 

Fossil, 75 species. L. silurian — Trias. North America, Europe. 

Maceocheilus, Phillips. 

Etymology, macros, long, and cheilos, lip. 
Synonym, Polyphemopsis, Portlock. 

Shell thick, ventricose, buccinoid; aperture simple, effuse 

M 



242 MANUAL OF THE MOILUSCA. 

'below; outer lip tMn, inner lip wanting, colnmella callous, 
slightly tortuous. 

Type, M. arculatus, ScUotlieini species. Devonian. Eifel. 

Distribution, 1 species (M. Japonicus), Korea Straits. 

Fossil, 12 species. Devonian — Carboniferous. Britain, 
Belgium. 

Family III. — Ceeithiad^. Cerites. 

Shell spiral, elongated, many-whorled, frequently varicose ; 
aperture cbanneled in front, with a less distinct posterior canal ; 
lip generally expanded in the adult; operculum horny and 
spiral. 

Animal with a short muzzle, not retractile ; tentacles distant, 
slender ; eyes on short pedicels, connate with the tentacles ; 
mantle-margin with a rudimentary siphonal fold ; tongue 
armed with a single series of median teeth, and three laterals 
or uncini. Mr. Wilton has examined the dentition of four 
Cerithiadce ; the teeth are broad, as in Melaniadce, with incurved 
and dentated summits. In Cerithidium the median teeth are 
slender with minute hooks. Habitat. Marine, estuary, or fresh 
water. 

Cerithium (Adans.), Bruguiere. 

Etymology, ceration, a small horn. 

Type, C. nodulosum. PL YIII., Fig. 16. 

Shell turreted, many-whorled, with indistinct varices ; aper- 
ture small, with a tortuous canal in front ; outer lip expanded ; 
inner lip thickened; operculum horny, paucispiral. PI. YIII., 
Fig. 16.* 

Distribution, 136 species. World-wide, the typical species 
tropical. Norway, Britain, Mediterranean, West Indies, India, 
Australia, China, PacijB.c, Gallapagos. 

Fossil, 460 species. Trias — . Britain, France, United 
States, &c. 

Sub-genera. Bhinoclavis, Sw. 0. vertagus. Canal long, 
bent abruptly ; operculum, sub-spiral. 

Bittium, Leach. C. reticulatum, PI. YIII., Fig. 17. Small 
northern species, ranging from low water to 80 fathoms. 

Tf if oris, Deshayes. C. perversum, PI. YIII., Fig. 18. 30 
species. Norway — ^Australia. 

Fossil, Eocene — . Britain, France. 

Shell sinistral ; anterior and posterior canals tubular. The 
third canal is only accidentally present, forming part of a 
varix. 

Cerithiopsis, Forbes. C. tuberculare, Britain. 



GASTEEOPODA. 243 

Shell like hittium ; proboscis retractile ; operculum pointed, 
nucleus apical. Eange 4 — 40 fathoms. 

PoTAMiDES, Brongniart. Fresh- water Cerites. 

Etymology, potamos, a river, and ides, i)atronyniic termination. 

Type, P. Lamarckii, Brong. ■ (= Cerit. tuberculatum, 
Brard.) 

Example, P. mixtus. PI. VIII., Fig. 19. 

Synonyms, Tjnnpanotomus, Klein, C. fuscatum, Africa. 
Pirenella, Eisso, 0. mammillatum, PL YIII., 
Fig. 22. 

Shell like cerithium, but without varices in 
the very numerous typical fossil species ; epi- 
dermis thick, olive brown; operculum orbicular, 
many-whorled. 

Distribution, 41 species. California, Africa, 
India. In the mud of the Indus they are 
mixed with species of ampuUaria, venus, 
purpura, ostrea, &c. (Major W. E. Baker.) 

Fossil (species included with cerithium), 
Eocene — . Europe. 

Suh-genera, Cerithidea, Sw., C. decollata, 

Pi. YIII., Fig. 24. Aperture rounded; lip 

expanded, flattened. Inhabit salt marshes, 

^ , , , A-L n • Fig- 97. Cerithidea,* 

mangrove swamps, and the mouths oi rivers ; 

they are so commonly out of the water as to have been taken for 

land-shells. Mr. Adams noticed them in the fresh waters of 

the interior of Borneo, creeping on pontederia and sedges ; they 

often suspend themselves by glutinous threads (Fig. 97). 

Distrihution, India, Ceylon, Singapore, Borneo, Philippines, 
Port Essington. 

Terehralia, Sw. Cerith. telescopium, PI. YIII., Fig. 21. 

Shell pyramidal; columella with a prominent fold, more or 
less continuous towards the apex; and a second, less distinct, on 
the basal front of the whorls (as in nerincea (Fig. 98), India, 
North Australia. 

T. telescopium is so abundant near Calcutta as to be used for 
b arning into lime ; great heaps of it are first exposed to the sun, 
to kill the animals. They have been brought alive to England. 
(Benson.) 

Fyrazus, Montfort. Cerit. palustre, PI. YIII., Fig. 20. 

Shell with numerous indistinct varices ; canal straight, often 
tubular ; outer lip expanded. India, North Australia. 

* C, obtusa, Lam. sp. copied from Adams. 
M 2 




244 



MAl^FAL OF THE MOLLUSCA. 



Ceritli. radulura and granulatum of the West African rivers 
approacL. very near tlie fossil potamides, but they have numerous 
varices. 

Lampania, Gray (batillaria, Cantor). Oerith. zonale. PL 
VIII., Fig. 23. 

Shell without varices, canal straight. Chusan. 

The fossil potamides decussatus, Brug., of the Paris baLin, 
resembles this section, and retains its spiral red bands. 



Nerinjea, Defrance. 

Etymology, nereis, a sea-njnnph. 

Example, N. trachea. Pig. 98. 

Shell elongated ; many-whorled, nearly cylindrical ; 
aperture channeled in front ; interior with continuous 
ridges on the columella and whorls. 

Fossil, 150 species. Inf. oolite — IJ. chalk. Britain, 
Prance, Germany, Spain, and Portugal. They are 
most abundant, and attain the largest size to the 
south ; and usually occur in calcareous strata, asso- 
ciated with shallow- water shells. (Sharpe.) 

Suh-ge.7i,era. 1. Nerinoea. Polds simple: 2 — 3 on 
the columella ; 1 — 2 on the outer wall ; columella solid, 
or perforated. Above 50 species. 

2. iVenwe^/a (Sharpe), columella solid; folds simple; 
columellar, — 1 ; outer wall, 1. 

3. Trochalia (Sharpe), columella perforated, with 
one fold ; outer wall simple, or thickened, or with one 
fold ; folds simple. 

4. Ptygmatis (Sharpe), columella solid or perforated, 
usually with 3 folds ; outer wall with 1 — 3 folds, some 
of them complicated in form. 




Kg. 98.* 



? P ASTIGIELLA, Eecve. 

Type, P. carinata, Eeeve. 

Shell like turritella; aperture with a short canal in front 
(Cuming Museum, and British Museum). 

Fossil, Eocene. Paris [Qerithium rugosum. Lam.). 

Aporehais, Aldrovandus. 

Etymology, aporrhais (Aristotle), " spout-shell," from aporrheo, 
to flow away. 

* Fig. 98. JVenruea trachea, Desl., partly ground down to show the form of the 
interior. Bath oolite, Eanville. Communicated by John Morris, Esq. 



GASTEROPODA. 



245 



S^ynonym, Chenopup, Philippi. 

Type, A. pes-pelecani. PL IV., Fig. 7, and Fig. 99. 

Shell v^iih. an elongated spire ; whorls numerous, tuberculated; 
aperture narrow, with, a short canal in front ; outer lip of the 
adult expanded and lobed oi digitated ; operculum pointed, 
lamellar. 

Animal with a short broad muzzle; tentacles cylindrical, 
bearing the eyes on prominences near their bases, outside; 
foot short, angular in front ; branchial plume single, long ; 




Fis;. 99.* 



lingual ribbon linear ; teeth single, hooked, denticulated ; 
uncini 3, the first transverse, 2 and 3 claw-shaped (Fig. 100). 
The dentition of Aporrhais is most like Stromhus and Carinaria ; 
and quite unlike the Oerithiadce with which it has been placed, 



yij^^^t^^T^ 




Fig. 100. Aporrhdis pes-pelecani. (Warington.) 



in accordance with the views of Professor Forbes. The animal 
is carnivorous. 

Distribution, 4 species. Labrador, Norway, Britain, Mediter- 
ranear, West Africa. Eange 100 fathoms. 

Fossil; see Fteroceras and Rostellaria ; above 200 species, 
ranging from the lias to the chalk, probably belong to this 
genus, or to genera not yet constituted. 

* Fig. 99. Aporrhais pes-pelcani, L., from a drawing by Joshua Alder, Esq., in the 
"British Mollusca." 




246 MANtJAL OF THE MOLLUSCA. 

Stetjthiolaria, Lam. 

Etymology, struthio, an ostricli (-foot), from tlie form of its 
aperture. 

Type, S. straminea, PL lY., Pig. 6. 

Shell turreted ; wliorls angular ; aperture truncated in front ; 
columella very oblique ; outer lip prominent in 
tlie middle, reflected and tldckened in tlie adult ; 
inner lip callous, expanded ; operculum claw- 
sliaped, curved inwards, with, a projection from 
the outer, concave edge (Fig. 101). 

Animal with an elongated muzzle ? tentacles 
cylindrical ; eye-pedicels short, adnate with the 

tentacles, externally: foot broad and short. 
Fig. 101. ,-rz- \ 

Operculum of (Kiencr.) 

istruthioiaricu. Distribution, 5 species. Australia and New 
Zealand, where alone it occurs sub-fossil. 

Family IY. — Melaniad^. 

Shell spiral, turreted ; with a thick, dark epidermis ; aperture 
often channeled, or notched in front ; outer lip acute ; operculum 
horny, spiral. The spire is often extensively eroded by the 
acidity of the water in which the animals live. 

A7iimal with, a broad non-retractile muzzle ; tentacles distant, 
subulate ; eyes on short stalks, united to the outer sides of the 
tentacles ; foot broad and short, angulated in front ; mantle- 
margin fringed ; tongue long and linear, with a median and 3 
lateral series of hooked multi-cuspid teeth. Often viviparous. 
Inhabiting fresh-water lakes and rivers throughout the warmer 
parts of the world. 

Melania, Lam. 

Etym,ology, melania, blackness (from melas). 

Type, M. amarula. PL YIIL, Fig. 25. 

iSynonyms, Thiara, Megerle. Pyrgula, Crist. 

Shdl turreted, apex acute (unless eroded) ; whorls orna- 
mented with striae or spines ; aperture oval, pointed above ; 
outer lip sharp, sinuous; operculum subspiral. PL YIIL, 
Fig. 25.* 

Distrilmtion, 361 species. South Europe, India, Philippines, 
Pacific Islands. Distinct groups in the southern States of 
North America. 



GASTEEOPODA. 247 

Fossil, 25 species. Wealden — . Europe (v. chemnitzia). 

Sub-genera. Melandtria, 'Bo^?}■^iich.. M. fluminea.* PI. YIII., 
Pig. 26. Aperture somewliat produced in front ; operculum 
with rather numerous whorls. This section includes some of 
the largest species of the genus, and is well typified by the 
fossil, M. Sowerhii (cerit. melanoides, Sby.), of the Woolwich 
sands. Old World, India, Philippines. 

Vibex, Oken, V. fuscatus, PL YIII., Pig. 29. Y. auritus. 
West Africa. Whorls spirally ridged, or muricated; aperture 
broadly channeled in front. 

Ceriphasia, Sw., C. sulcata. North America. Aperture like 
vibex ; slightly notched near the suture. 

Hemisinus, Sw., H. lineolatus. West Indies. Aperture 
channeled in front. 

Melafusus, Sw, (lo, Lea. Glottella, Gray.) M. fluviatilis. 
PL YIII,, Pig. 27. United States. Aperture produced into a 
spout in front. 

Meldtoma, Anthony (not Sw.) M. altilis. 

Shell like anculotus ; with a deep slit at the suture. United 
States. 

Anculotus, Say. A. prsemorsus. PL YIII., Pig. 28. 

Shell globular ; spire very short ; outer lip produced. United 
States. 

Amnicola, G. and H. A. isogona. PL IX., Pig. 23. United 
States ; inhabits the fresh waters of New England, gregarious 
on stones and submerged plants. 

Chilostoma, Desh. M. marginata, Eocene. Paris. Peristome 
thickened externally, all round. 

Glea, Bens. C. annesleyi. South India. 

Paltidomtjs, Swainson. 

Etymology, palus, a marsh, and domus, home. 

Synonyms, Tanalia, Gray. Hemimitra, Sw. 

Type, P. aculeatus, Gm. species. PL IX., Pig. 34. 

Shell turbinated, smooth, or coronated ; outer lip crenulated ; 
olivaceous with dark brown spiral lines. 

Distribution, 25 species. Ceylon (Himalaya ?) in the moun- 
tain-streams, sometimes at an elevation of 6,000 feet. The 
Himalayan species [melania conica, Gray, hemimitra retusa, Sw., 
and several others), referred to this genus, have a concentric 
operculum, like paludina. 

* This is a good section of melania, but Mr. Gray's type does not well represent it, 
being more like a pirena in the form of its aperture. 



248 MANUAL OP THE MOLLUSC A. 

Melajstopsis, Lam. 

Tijpes, M. buccinoides, M. costata. PI. YIII., Fig. 30. 

Shell body-wlioii elongated ; spire short and pointed ; aper- 
tirre distinctly notched in front ; inner lip callous ; operculum 
sub-spiral. 

Distribution, 21 species. Spain, Asia Minor, New Zealand. 

Fossil, 25 species. Eocene — . Europe. 

Sub-genus, Pirena, Lam, (faunus, Montfort) P. atra. PI, 
YIIL, Pig. 31. Spire elongated, many-whorled ; outer lip of 




Fig. 102. Pirena atra. (Wilton.) 

the adult produced. Teeth 3. 1. 3, as in Pig. 102. 

Distribution, 4 species ? South Africa, Madagascar, Ceylon, 
Philippines. 

Family Y. — Tureitellid^. 

Shell tubular, or spiral ; upper part partitioned off; aperture 
simple ; operculum horny, many-whorled. 

Animal with a short muzzle ; eyes immersed, at the outer 
bases of the tentacles ; mantle-margin fringed ; foot very short ; 
branchial plume single; tongue armed; dentition 3. 1. 3. 

TUHBITELLA, Lam. 

Etymology, diminutive of turris, a tower. 

Synonyms, Terebellum, Torcula, Zaria, and Eglisia (Gray.) 

Type, T. imbricata. PI. IX., Pig. 1. 

Shell elongated, many-whorled, spirally striated; aperture 
rounded, margin thin ; operculum horny, many-whorled, with 
a fimbriated margin. 

Animal with long, subulate tentacles ; eyes slightly promi- 
nent ; foot truncated in front, rounded behind, grooved beneath; 
branchial plume very long ; lingual ribbon minute ; median 
teeth hooked, denticulated ; uncini 3, serrulated. Carnivorous ? 

Distribution, 73 species. "World-wide. Eanging from the 
Laminarian Zone to 100 fathoms. West Indies, United States, 
Britain (1 species), Iceland, Mediterranean, West Africa, China, 
Australia, West America. 

Fossil, 172 species. Neocomian — . Britain, &c., South 
America, Australia, Java. 



GASTEEOrODA. 249 

Suh-gmera, Proto, Defr.^ P. cathedralis, PL IX., Fig. 3, 
aperture truncated below. 

Mesalia, Grray, M. sulcata (var.), PI. IX., Fig, 2. Greenland 
—South Africa. 

Fossily Eocene. Britain, France. 

CiECTJlMr, Fleming. 

Synonyms, Corniculina, Miinster. Broclius, Bronn. Odontl- 
dium, Phil. 

Type, 0. trachea, PL IX., Fig. 5. Young species, Fig» 6. 

Shell at first discoidal, becoming decollated when adult; 
tubular, cylindrical, arched; aperture round, entire; apex 
closed by a mammillated septum. Operculum horny, many- 
whorled. Lingual teeth, ; uncini, 2, the inner broad and 
serrulated. 

Distribution, Britain, 11 species, 10 fathoms. Mediterranean. 

Fossil, 4 species. Eocene- — . Britain, Castelarquato. 

Yeemettts, Adanson. Worm-shell. 

Synonyms, Siphonium, Gray. Serpuloides, Sassi. 

Types, Y. lumbricalis, PL IX., Fig. 7. 

Shell tubular, attached ; sometimes regularly spiral when 
young ; always irregular in its adult growth ; tube repeatedly 
partitioned off ; aperture round ; operculum circular, concave 
externally. 

Distribution, 31 species. Portugal, Mediterranean, Africa, 
India. 

Fossil, 12 species. Neocomian — , Britain, France, &c. 

? S'ah-genus> Spiroglyphus, Daud. S. spirorbis Dillwyn species, 
irregularly tubular ; attached to other shells, and half buried 
in a furrow which it makes as it grows. Perhaps an annelide ? 

Fetaloconchus, sculpturatus, Lea, 1843. 

'Miocene, United States, St. Domingo, South Europe. 

Shell with two internal ridges running spirally along the 
columella, becoming obsolete near the apex and aperture. 

SlLIQUAHIA, Brug. 

Etymology, siliqua, a pod. 

Typo, S, anguina, PL IX., Fig. 8. 

Shell tubular ; spiral at first, irregular afterwards ; tube with 
a continuous longitudinal slit. 

Distrihution, 8 species* Mediterranean, North Australia. 
Found in sponges. 

Fossil, 10 species. Eocene — . France, &c. 

M 3 



250 MAJftl-LL OF THE MOLLt/SCA, 

ScAiiABiA, Lam. Wentle-trap. 

Etymology, scalaris, like a ladder. 

Type, S» pretiosa, PL IX., Fig. 9. (=== T. scalaris, L.) 

Shell mostly pure wliite and lustrous ; turreted ; many- 
whorled; whorls round, sometimes separate, ornamented with 
numerous transverse ribs ; aperture round ; j)6i'istome con- 
tinuous; operculum horny, few-whorled. 

Animal with a retractile proboscis-like mouth ; tentacles 
close together, long and i^ointed, with the eyes near their outer 
bases ; mantle-margin simple, with a rudimentary siphonal 
fold ; foot obtusely triangular, with a fold (mentum) in front. 
Lingual dentition nearly as in huUa ; teeth ; uncini nume- 
rous, simple ; sexes distinct ; predacious ? Eange from low 
Water to 80 fathoms. The animal exudes a purple fluid when 
molested. 

Distrihution, 104 species. Mostly tropical. Greenland, 
Norway, Britain, Mediterranean, West Indies, China, Australia, 
Pacific, "West America. 

Fossil, nearly 100 species. Coral-rag — . Britain, North 
Am.erica, Chili, India. 

Family YI. — ^LiTTORmro^. 

Shell spiral, turbinated or depressed, never pearly ; aperture 
rounded ; peristome entire ; operculum horny, pauci- spiral. 

Animal with a muzzle-shaped head, and eyes sessile at the 
outer bases of the tentacles ; tongue long, armed with a median 
series of broad, hooked teeth, and 3 oblong, hooked uncini. 
Branchial plume single. Foot with a linear duplication in 
front, and a groove along the sole. Mantle with a rudimentary 
siphonal canal ; operculum lobe appendaged. 

The species inhabit the sea, or brackish water, and are mostly 
littoral, feeding on algae. 

LiTTomisrA, Ferussac. Periwinkle, 

Etymology, littoralis, .belonging to the sea-shore. 
Type, L. littorea, PI. IX., Pig. 10. 
Bhdl turbinated, thick, pointed, few-whorled; 
aperture rounded, outer li23 acute, columella rather 
flattened, imperforate, operculum pauci-spiral, Pig. 
103. Lingual teeth hooked and trilobed ; uncini 
Fig 103. hooked and dentated (Pig. 104). 
Distrihution, 131 species. The periwinkles are found on the 
Rca--hore in all parts of the world. In the Baltic they live 




GASTEROPODA. 



251 



witlim the influence of fresli water, and frequently become dis- 
torted ; similar monstrosities are found in the Norwich crao-. 




Fig. 104, Littorina littorea. (Warington.) 



The common species [L, littorea) is oviparous ; it inhabits the 
lowest zones of sea-^weed between tide-marks. An allied species 



r, rostrum or muzzle. 
k, buccal mass. 
g, nervous ganglia 

(reproductive orifice, on 

the right side). 
s, salivary gland. 
£E, oesophagus, 
I, lingual coH. 
■m, shell-muscle. 

b, branchia or gill, 

c, heart. 
n, aorta. 

e, stomach. 

/, liver. 

h, biliarj'- canal. 

t, intestine. 

a, anus. 

o, ovary. 

d, oviduct. 
u, uterus. 

o', ovarian orifice. 
X, renal organ. 
y, muctis gland. 



Fig. 105. Littorina IMof alls $ '. (after Sotileyet). Animal removed from its shell; 
branchial cavity and back laid open. 

(X. rudis) frequents a higher region, where it is scarcely reached 
])y the tide * it is viviparous, and the young have a hard shell 




252 MAiniAL OF THE MOLLrSCA. 

before their birth., in consequence of wbidi the species is not 
eaten. The tongue of the periwinkle is two inches long ; its 
foot is divided by a longitudinal line, and in walking the sides 
advance alternately. The periwinkle and trochus are the food 
of the thrush, in the Hebrides, during winter. The lingual canal 
of the periwinkle passes from the back of the mouth under the 
oesophagus for a short distance, then turns up on the right 
side, and terminates in a coil (like spare roipe) resting on the 
plaited portion of the gullet. It is 2| inches long, and contains 
about 600 rows of teeth ; the part in use, arming the tongue, 
comprises about 24 rows.* The dental ribbon ot Bi sella is above 
2 inches long, and coiled as in Littorina. (Wilton.) 

Fossil, 10 species ? Miocene — . Britain, &c. It is probable 
that a large proportion of the oolite and cretaceous shells 




Fig. 106. Operculum and teeth of JRisella. (Wilton.) The central tooth should be 
poiated, not blunt as in the figure. 

referred to turlo belong to this genus, and especially to the 
section tedaria. 

Sub-genera. Tedaria, Cuvier, 1817 (= Pagodella, Sw.), L. 
pagodus, PI. IX., Fig. 11. 

Shell muricated or granulated ; sometimes with an umbilical 
fissure ; operculum with a broad, membranous border. "West 
Indies, Zanzibar, Pacific. 

Modulus, Gray. M. Tectum, PI. IX., Pig. 13. 

Shell trochiform or naticoid ; porcellanous ;' columella per- 
forated ; inner lip worn or toothed ; operculum horny, few- 
whoi led. 

* r I Fig. 105 is shown the manner in which a gasteropod may be laid out for 
exan juation, under water : the body requires to be fixed, and the cut edges of the 
mantle to be kept open with needle points. A convenient trough may be made of a 
plain earthenware soap-dish, by cutting a piece of sheet-cork (such as bootmakers use) 
to fit the bottom, and fixing it to a piece of sheet-lead of the same size with a couple 
of ii'dia rubber bands. The instruments required for dissecting are simply a pair of 
fine-pointed scissors, a few broken needles, a penknife, or scalpel, and a pair of forceps 
with fine curved points. 



GASTEROPODA. 253 

Distribution^ Philippines, "West America. 

Fossarus (Adans.), Philippi. F. sulcatus, PI. IX., Eig. 12. 

Synonym, Phasianeina, Wood. 

Shell perforated ; inner lip thin ; operculum not spiral. 

Distribution, Mediterranean. 

Fossil, 3 species. Miocene' — . Britain, Mediterranean. 

Risella, Gray. Lit., melanostoma, PI. IX., Fig. 14. 

Sliell trochiform, with, a flat or concave base ; whorls keeled ; 
apertnre rhombic, dark or variegated, operculum pauci-spiral. 

Distribution, New Zealand. 

Conradia, Adams. Aperture circular. 3 species, Japanese seas. 

Couthouyia, Adams. Shell ovate, with an acute spine ; aper- 
ture semi-oval. 1 species, Japanese seas. 

SOLAEIUM, Lam. Stair-case shell. 

Etymology, solarium, a dial. 

Synonyms, architectoma, Bolten. Philippia, Grray. Helico- 
cryptus, D'Orbigny ? 

Type, S. perspectivum, PL IX., Fig. 15. 

Shell orbicular, depressed ; umbilicus wide and deep ; aper- 
ture rhombic ; peristome thin ; operculum horny, sub-spiral. 

The spiral edges of the whorls, seen in the umbilicus, have 
been fancifully compared to a winding stair-case. 

Distribution, 25 species. Tropical seas. Mediterranean, East 
Africa, India, China, Japan, Australia, Pacific, West America. 

Fossil, 56 species. Eocene — . Britain, &g. 26 other species 
(oolites — chalk) are provisionally referred to this genus ; the 
cretaceous species are nacreous (v. trochus). 

Sub-genera. Torinia, Gray. T. cylindracea, oper- 
culum conical, multi-spiral, with projecting edges, 
Fig. 107. Living, New Ireland. 

Fossil, Eocene. Britain, Paris. 

Bifrontia, Desh. [Omalaxis, Desh.) S. bifrons, 
discoidal, the last whorl disengaged. 1 recent 
species. Madeira. Fig. 107.* 

Fossil, 6 species. Eocene. Paris, Britain. 
? Orbis, Lea. Discoidal, whorls quadrate. 

Fossil, Eocene. America. 

Discohelix (calculiformis) Dunker, 1851. Lias, Gottingen. 
This name was proposed for the depressed Euomphali of the 
Lower Oolites, of which there are several species in Normandy 
and England. 

« Operculum of S. patulum, Lam. |, ffom Deshayes. 




254 MAKTTAL OF THE MOLLTJSCl. 

Shell usually sinistral, flat, or concave above ; aperture 
quadrangular. 

Flatystoma (Suessi) Homes, 1855. Trias, Hallstadt. 

Shell discoidal, sinistral ? sculptured ; peristome suddenly- 
expanded, plain; aperture with an inner rim, circular, a ad 
deflected (upwards) at right angles to the plane of the shell. 
Several examples have occurred. 

Philippia (lutea) Gray, has a multi-spiral operculum, and 
the animal is like Trochus. (Philippi.) 

Faludestrina (lapidum) D'Orbigny part. Eresh waters of 
South America. 

Shell conic, few-whorled, epidermis green ; aperture oblique, 
peristome abruptly reflected ; operculum claw-like. The typical 
species appear to be Melaniadce, but some small shells like 
Hydrobia have been included in the genus. 

PHORirs, Montfort. Carrier-shell. 

Etymology, phoreus, el carrier. 

Synonyms, Onustus, Humph., Xenophorus, I'ischer. 
Examples, P. conchyliophorus, Born. P. corrugatus, PL X., 
Fig. 1. 

Shell trochiform, concave beneath ; whorls flat, 

with foliaceous or stellated margins, to which shells, 

stones, &c., are usually affixed; aperture very 

f /"^^^W oblique, not pearly ; outer lip thin, much produoad 

\V v>^^ above, receding far beneath * operculum .horny, im.- 

^^^=^^ bricated, nucleus external, as in purpura and palii-' 

rig. 108. ^omus, with the transverse scar seen through it, Fig* 

108. (Museum Cuming.) 

Animal with an elongated (non-retractile?) proboscis; ten- 
tacles long and slender, with sessile eyes at their outer bases ; 
sides plain ; foot narrow, eloiigated behind. — Adams. Eelated 
to scalaria ? 

Most of the phori attach foreign substances to the margins of 
their shells as they grow, particular species affecting stones, 
whilst others prefer shells or corals. They are called "mineral- 
ogists" and " conchologists," by collectors; P. Solaris and 
P. indicus are nearly or quite free from these, disguises. They 
are said to frequent rough bottoms, q^nd to scramble over the 
ground, like the strombs, rather than |^ide evenly. 

Distribution, 9 species. West Indies, India, Malacca, Philip- 
pines, China, and West America, f -^ 

Fossil, 15 species. Chalk ? — Eocene — . Britain and France. 




GASTJEHOfODA. 256 

Shells extremely like the recent phorus, are met with, even in 
the carb. limestone and Has. 

Lacusta, Turton. 

Etymology, lacuna, a fissure. 

Ti/pe, L. pallidula (PL IX., Fig. 16). 

Synonym, Medoria, Gray. 

Shell turbinated, thin ; aperture semi-lunar ; columella flat- 
tened, with an umbilical fissure ; operculum pauci-spiral. 

Animal ; operculigerous lobe furnished with lateral wings and 
tentacular filaments. Teeth 5 cusped ; uncini 1, 2, dentated, 
3 simple. Spawn [ootheca) vermiform, thick, semi- circular. 
Eange, low water — 50 fathoms. 

Distribution, 16 species. Northern shores, Norway, Britain, 
Spain. 

Fossil, 1 species. Glacial beds, Scotland. 

LiTioPA, Eang. 

Etymology, litos, simple, ope, aperture. 

Type, L. bombyx (PI. IX., Pig. 24). 

Shell minute, pointed ; aperture slightly notched in front ; 
outer lip simple, thin ; inner lip reflected ; operculum spiral. 

Distribution, 6 species. Atlantic and Mediterranean, on float- 
ing sea-weed, to which they adhere by threads. 

Fossil, 1 species. Pliocene (Crag). 

EissoA, Premenville. 

Etymology, named after Eisso,* a Prench zoologist. 

Type, E. labiosa (PL IX., Pig. 17). 

Synonym, Cingula, Plem. 

Shell minute, white or horny; conical, pointed, many-whorled; 
smooth, ribbed, or cancellated; aperture rounded; peristome 
entire, continuous ; outer lip slightly expanded and thickened ; 
operculum sub-spiral. 

The animal has long, slender tentacles, with eyes on small 
prominences near their outer bases ; the foot is pointed behind ; 
the operculigerous lobe has a wing-like process and a filament 
[cirrus) on each eide. Lingual teeth single, sub-quadrate, 
hcoked, dentated; uncini 3; 1 dentated, 2, 3, claw-shaped. 
They range from high-water to 100 fathoms, but abound most 
in shallow water, near shore, on beds oifucus and zostera. 

Distribution, about 70 species. Universally distributed, but 

* It is much to be regretted that some moclem naturalists have tried to find out and 
bring nt : us- the obscure genera of Kisso, and the worthless fabrications of Montfort 
and Eafinesque, which had better have remained unknown. 



256 MAjSTCTAL of the MOLItlSCA. 

most abundant in tlie nortli temperate zone. North America, 
West Indies, Norway, Britain, Mediterranean, Caspian, India, 
&c. Rissoa parva adheres to sea-weeds by threads, like litiopa. 
(Gray.) 

Fossil, 100 species. Permian — -. Britain, France, &c. 

Sub-genera. Eissoina^ D'Orbigny. Aperture channrled in 
front. 66 living species. Fossil (10 species Bath oulite. — 
Britain.)— -■:!rw6a, Lea? America. 

Hydrobia, Eartm. (=:Paludinella, LoY^n.) Shell sm.ooth ; foot 
rounded behind ; operculigerous lobe without filament, Tyjye, 
littorina ulvse (PI. IX., Fig. 18). Distribution, 50 si^gcibe. Fossil, 
10 species. Wealden — '■. Britain, &c. 

Syncera, Gray (Assiminea, Leach). S. hepatica. Shell like 
Hydrobia ; tentacles connate with the eye pedicels, which equal 
them in length. Teeth 5 — 7 cusped; uncini 1, 2, dentated, 3 
rounded. Distribution, 2 species, brackish water. Britain and 
India. 

Nemattira, Benson. N. deltse (PL IX., Fig. 21.) • Aperture 
contracted ; peristome entire ; operculum pauci-spiral. Fossil, 
Eocene. Isle of Wight. 

Jeffreysia, Alder (==Eissoella, Gray, MS.), J. diaphana. Shell 
minute, translucent ; operculum semilunar, imbricated, with a 
projection from the straight, inner side (PL IX., Fig. 19). 
Head elongated, deeply cleft, and produced into two tentacular 
processes ; mouth armed with denticulated jaws, and a spinous 
tongue ; tentacles linear, eyes far behind, prominent, only visible 
through the shell ; foot bi-lobed in front. 6 species. Britain. 
On sea-weed, near low- water. (Alder.) There are eight other 
species in the Japanese seas. 

SkeIstea, Fleming. 

Etymology, named after Dr. Skene, of Aberdeen, a contem- 
porary of Linneeus. 

Synonym, Delphinoidea, Brown. 

Tijpe, S. planorbis (PL IX., Fig. 20). 

Shell minute orbicular, depressed, few-whorled ; peristome 
continuous, entire, round ; operculum pauci-spiral. Animal\\k.Q 
rissoa, foot rounded behind. Found under stones at low- water, 
and amongst the roots of corallina officinalis. 

Distribution, ? species. Northern seas, Norway, and Britain. 
S. cornuella. Straits of Korea (Adams). 

? TRtnsrOATELLA, Eisso. Looping-snail. 
Type, T. truncatula (PL IX., Fig. 25). (Mus., Hanley ) 



GASTEROPODA- 257 

She m'nute, cylindrical, truncated ; whorls striated trans- 
versely; aperture oval, entire; peristome continuous; operculum 
sub -spiral! 

Animal -with short, diverging triangular tentacles ; eyes 
centrally behind ; head bi-lobed ; foot short, rounded at each 
end. (Forbes.) 

The tritncatellce are found on stones and sea-weeds between 
tide-marks, and survive many weeks out of the water. (Lowe.) 
They walk by contracting the space between their lips and foot, 
like the geometric caterpillars. (Gray.) They are found semi- 
fossil along with the human skeletons in the modern limestone 
of Guadaloupe. 

Distribution, 15 species. West Indies, Britain, Mediterranean, 
Eio, Cape, Mauritius, Philippines, Australia, Pacific. (Cuming.) 

? LiTHOGLYPHTTS, Mogerle. 

Type, L. fuscus (PI. IX., Fig. 22). 

Shell naticoid, often eroded ; whorls few, smooth ; aperture 
large, entire ; peristome continuous, outer line sharp, inner lip 
callous ; umbilicus rimate ; epidermis olivaceous ; operculum 
pauci-spiral. 

Distribution, 5 species. Europe and Oregon. 

Family YII. — Paxudinid^. 

Shell conical or globular, with a thick, olive-green epidermis ; 
aperture rounded ; peristome continuous, entire ; operculum 
horny or shelly, normally concentric. 

Animal with a broad muzzle ; tentacles long and slender ; 
eyes on short pedicels, outside the tentacles. Inhabiting fresh 
waters in all parts of the world. 

PAiiUDrisrA, Lam. Eiver-snail. 

Etymology, palus [paludis), a marsh. 

Synonym, Yiviparus, Gray. 

Type, P. Listeri (PI. IX., Fig. 26). (P. vivipara, Fig. 68.) 

Shell turbinated, with round whorls ; aperture slightly angular 
behind ; peristome continuous, entire ; operculum horny, con- 
centric. Animal with a long muzzle, and very short eye- 
pedicels ; neck with a small lappet on the left side, and a larger 
on the right, folded to form a respiratory siphon ; gill comb-like, 
single; tongue short; teeth single, oval, slightly hooked and 
denticulated ; uncini 3, oblong, denticulated. The paludinse are 



258 



MANUAL OF THE MOLLUSCA. 



viviparous ; tlie shells of the young are omamented with. f5piral 
rows of epidermal cirri. 

Distribution, 60 species. Eivers and lakes throughout the 
northern hemisphere ; Black Sea, Caspian. 

Fossil, 53 species. Wealden — . Britain, &c. 

Svb-genus. Bithynia (Prideaux), Gray. B. tentaculata' 
(PL IX., Fig. 27). Shell small; operculum shelly. Animal 
oviparous ; with only one neck-lappet, on the right side. The 
bithynia oviposit on stones and aquatic plants ; the female lays 
from 30 to 70 eggs in a band of three rows, cleaning the surface 
as she proceeds ; the young are hatched in three or four weeks, 
and attain their full growth in the second year. (Bouchard.) 

Ampttllaeia, Lam. Apple-snail, or idol-sheU. 

Etymology, ampnlla, a globular flask. 

Example, A. globosa (PI. IX., Pig. 30). 

Synonym, Pachylabra, Sw. 

Shell globular, with a small spire, and a large ventricose body- 
whorl ; peristome thickened and slightly reflected ; operculum 
shelly. 

Animal with a long incurrent siphon, formed by the left neck- 




Fig. 109* 

lappet; left gill developed, but much smaller than the right ;t 
muzzle produced into two long tentacular processes ; tentacles 

* Fig. 109. AmpuUaria canaliculata, Lam. (from D'Orb). South America. The 
branchial siphon (s) is seen projecting from the left side ; o, operculum. 

t The ampuUaria is said to have a pulmonic sac in addition to its gills (Gray, Owen), 
but we have not met with specimens sufficiently well preserved to exUibit it. It would 
be very desirable to examine the amp. cornu-arietis, in which, probably, the giUs are 
BjTmnetrical, a-s in the cephalopods. 



GASTEEOPODA. 



259 



extremely elongated, slender. Inhabits lakes and rivers 
throughout the warmer parts of the world, retiring deep into the 
mud in the dry season, and capable of surviving a drought, or 
removal from the water for many years. In the lake Mareotis, 
and at the mouth of the Indus, ampuUariae are abundant, mixed 
w th marine shells. Their eggs are large, enclosed in capsules, 




rig. 110, AmpuUaria globosa. (Wilton.) 

and aggregated in globular masses. The dentition of A. glohosa 
is shown in Eig. 110. 

Distribution, 136 species. South America, West Indies, Africa, 
India. 

Sub-genera. Pomus, Humph. A. ampullacea. Operculum 
horny. 

Marisa, Gray (ceratodes, Guilding). A. cornu-arietes (PL IX., 
Pig. 31). Operculum horny. Shell discoidal. 

Asolene, D'Orbigny. A. platse. Animal without a respiratory 
siphon ; operculum shelly. Distribution, South America. 

Lanistes, Montf. A. bolteniana, L. (PI. IX., Fig. 32). Shell 
reversed, umbilicated, peristome thin ; operculum horny. Dis- 
tribution, West Africa, Zanzibar, Nile. 

Meladomus, Sw. Paludina olivacea, Sby. Shell reversed, 
imperforate ; peristone thin ; operculum horny. 

? Amphibola, Schumacher. 

Synonyms, Ampullacera, Quoy. Thallicera, Sw. 

Type, A. australis (PI. IX., Fig. 33). 

Shell globular, with an uneven, battered surface ; columella 
fissured ; outer lip channeled near the suture ; operculum horny, 
sub-spiral. Animal without tentacles; eyes placed on round 
lobes ; air-breathing ; respiratory cavity closed, except a small 
valvular opening on the right side ; a large gland occupies the 
position of the gill of paludina; sexes united, (Quoy,) Mr. 
Gray places this genus amongst the true pulmonifera. 

Distribution, 3 species. Shores of New Zealand and the Pacific 
Islands. The living shells sometimes have serpulm attached to 
them. (Cuming.) They are eaten by the New Zealanders. 



260 MAISTTJAL OF THE MOLLUSCA. 

Yalvata, Miiller. Yalve-sliell. 

Types, V. piscinalis (PL IX., Fig. 28). Y. cristata (PL IX., 
Pig. 29). 

Shell turbinated, or discoidal, lunbilicated ; whorls round or 
keeled; aperture not modified by the last whorl; peristome 
entire ; operculum horny, multi-spiral. 

Animal with a produced muzzle ; tentacles long and slender, 
eyes at their outer bases ; foot bi-lobed in front ; branchial 
plume long, pectinated, partially exserted on the right side, 
when the animal is walking. Lingual teeth broad ; uncini 3, 
lanceolate ; all hooked and denticulated. 

Distribution, 18 species. Bri'tain and North America. 

Fossil, 19 species. Wealden — . Britain, Belgium, &c. 

Pamily YIII. — Nerited^. 

Shell thick, semi-globose ; spire very small ; cavity simple, 
from the absorption of the internal portions of the whorls ; aper- 
ture semi-lunate ; columellar side expanded and flattened ; outer 




Fiff. 111. * 



Hp acute ; operculum shelly, sub-spiral, articulated. 

At each end of the columella there is an oblong muscular im- 
pression, connected on the outer side by a ridge, on which the 
operculum rests ; within this ridge the inner layers of the shell 
are absorbed. 

Animal with a broad, short muzzle, and long slender tentacles; 
eyes on prominent pedicels, at the outer bases of the tentacles ; 
foot oblong, triangular. Lingual dentition similar to the tur- 
hinidce. Teeth 7 ; uncini very numerous. 

Nebita, L. ISTerite. 

Etymology, Nerites, a sea-snail, from nereis. 
Tijpe, N. ustulata (PL IX., Pig. 35). 

* Fig. 111. Nerita polita, L. (from Quoyand Gaimard), New Ireland!. 




GASTEROPODA. 261 

Shell thick, smooth or spirally grooved; epidennis horny; 
outer iip thickened and sometimes denticulated 
within; columella broad and flat, with its inner (Hs^--^ 
edge straight and toothed; operculum shelly, 
Fig. 112. 

Distribution^ 113 species. Nearly all warm seas. 
West Indies, Eed Sea, Zanzibar, Philippines, Fig. 112.* 
Australia, Pacific, West America. (Cuming.) Many of the 
American species dwell in the streams; one species at the 
Philippines sometimes climbs up trees. 

Fossil, 60 species. Lias—. Britain, &c. The palaeozoic nerites 
are referred by D'Orbigny to turho, natica, &c. N. haliotis is a 
jpileopsis. 

Sub-genera. Neritoma, Morris, 1849. N. sinuosa, Sby. 
Portland stone, Swindon. (Mus., Lowe.) Shell ventricose, 
thick ; apex eroded ; aperture with a notch in the middle of the 
outer lip. Casts of this shell are common, and exhibit the 
condition of the interior characteristic of all the nerites ; it was 
probably fresh water. 

Neritopsis, Grrateloup. N. radula (PI. YIIL, Pig. 9). Shell 
like nerita ; inner lip with a single notch in the centre. 

Distribution, 1 species. Pacific. 

Fossil, 20 species. Trias ? Britain, Prance, &c. 

Velates, Montf. N. perversa, Gm. (PL IX., Pig. 36). Inner 
lip very thick and callous ; outer lip prolonged behind, and par- 
tially enveloping the spire. 

PiLEOLTJS (Cookson), J, Sowerby. 

Etymology, pileolus, a little cap. 

Type, P. plicatus (PI. IX., Pigs. 37, 38). 

Shell limpet-like above, with a sub-central apex; concave 
beneath, with a small semi-lunar aperture, and a columellar 
disc, surrounded by a broad, continuous peristome. 

Distribution, marine ; only known as fossils of the Bath oolite, 
Ancliffe, and Minchinhampton, 3 species, P. neritoides is a 
neritina. 

Neeitina, Lam. Presh- water nerite. 

Examples, N. zebra (PI. IX., Pig. 39), N. crepidularia 
(PL IX., Pig. 40). 

Shell rather thick at the aperture, but extensively absorbed 
inside ; outer lip acute ; inner straight, denticulated ; operculum 

* Fig. 112. Operculum of N. peloronta. West Indies. 



262 MANTTAL OF THE MOLLTJSCA. 

slaelly, with, a flexible border ; sligbtly toothed on its straight 
edge. 

Animal like nerita ; lingual teeth. ; median, minute ; laterals 
3, 1 large, sub-triangular 2, 3 minute ; uncini about 60, first 
very large, hooked, denticulated ; the rest equal, narrow, hooked, 
denticulated. 

The neritinge are small globular shells, ornamented with a 
great variety of black or purple bands and spots, covered with a 
polished horny epidermis. They are mostly confined to the fresh, 
waters of warm regions. One species [N. fluviatilis) is found in 
British rivers, and in the brackish water of the Baltic. Another 
extends its range into the brackish waters of the North American 
rivers ; and the West Indian N. viridis and meleagris are found 
in the sea. 

^'N. crepididaria has a continuous peristome, and approach.es 
navicella in form ; it is found in the brackish waters of India. 
N. corona (Madagascar) is ornamented with a series of long 
tubular spines. 

Distribution, 111 species. West Indies, Norway, Britain, 
Black Sea, Caspian, India, Philippines, Pacific, West America. 

Fossil, 20 species. Eocene — . Britain, Prance, &c. 

Nayicella, Lam. 

Etymology, navicella, a small boat. 
Type, N. porcellana. PI. IX., Pig. 41. 

Skill, oblong, smooth, limpet-lLke ; with a posterior, sub- 
marginal apex; aperture as large as the shell, with a small 




Fig. 113. Navicella. (Wilton.) 

columellar shelf, and elongated lateral muscular scars; oper- 
culum very small, shelly. 

Distribution, 33 species. India, Mauritius, Moluccas, Aus- 
tralia, Pacific. 

Navicella inhabits fresh waters, adhering to stones and plants. 

Median tooth small ; laterals 3, first large, trapeziform, 2, 3, 
minute ; uncini numerous, first large, strong, and opaque, the 
rest slender, translucent, with denticulate hooks (Fig. 113). 



GASTEROPODA. 263 

Family IX. — Ttjbbinidjj:. 

Shell spiral, turbinated or pyramidal, nacreous inside ; oper- 
culum calcareous and pauci-spiral, or liorny and multi-spiral. 

Animal with, a short muzzle ; eyes pedunculated at the outer 
bases of the long and slender tentacles ; head and sides orna- 
mented with fringed lobes and tentacular filaments {cirri) ; 
branchial plume single ; lingual ribbon long and linear, chiefly 
contained in the visceral cavity ; median teeth broad ; laterals 
5, denticulated; uncini very numerous (sometimes nearly 100), 
slender, with hooked points (Fig. 15, A). 

Marine, feeding on sea- weeds (algce). 

The shells of nearly all the turbinidse are brilliantly pearly 
when the epidermis and outer layer of shell are removed ; many 
of them are used in this state for ornamental purposes. 

Ttjebo, L. Top-shell. 

Etymology, turho, a whipping-top. 

Synonyms, Batillus, Marmorostoma, Callopoma, &c. — Gray. 

Type, T. marmoratus. PI. X., Fig. 2. 

Shell turbinated, solid ; whorls convex, often grooved or 
tuberculated ; aperture large, rounded, slightly produced in 
front ; operculum shelly and solid, callous outside, and smooth, 
or variously grooved and mammillated, internally horny and 
pauci-spiral. In T. sarmaticus the exterior of the operculum is 
botryoidal, like some of the tufaceous deposits of petrifying 
wells. 

Animal with pectinated head-lobes. 

Distribution, 60 species. Tropical seas. West Indies, Medi- 
terranean, C?cpe, India, China, Australia, New Zealand, Pacific, 
Peru. 

Fossil, 360 species (including littorina.) L. Silurian — . 
Universal. 

Phasiajstella, Lam. Pheasant- shell. 

Synonyms, Eutropia (Humphrey), Gray. Tricolea, Eisso. 

Type, P. australis. PL X., Fig. 3. 

Shell elongated, polished, richly coloured; whorls convex; 
aperture oval, not pearly ; inner lip callous, outer thin ; oper- 
culum shelly, callous outside, sub -spiral inside. 

Animal with long ciliated tentacles ; head-lobes pectinated, 
wanting in the minute species ; neck-lobes fringed ; sides 
ornamented with three cirri; branchial plume long, partly 
free ; foot rounded in front, pointed behind ; its sides moved 
alternately in walking ; lingual teeth even-edged ; laterals 5, 



264 MAlJfUAL OF THE MOLLTJSCA. 

hooked, denticulated; uncini about 70, gradually diminislLmg 
outwards, hooked and denticulated. 

Distribution, 25 species. Australia, large species; India, 
Philippines, small species ; Mediterranean, Britain, West 
Indies, very small species. 

Fossil, 70 species. Devonian (?). Europe. 

The similarity of the existing Australian fauna to that of the 
European oolites strengthens the probability that some, at 
least, of these fossil shells are rightly referred to Phasianella. 



Fig. 114.* 

Impeeator, Montfoi*t. 
Type, I. imperialis. PL X., Eig. 4. 
Synonym, Calcar. 

Shell trochiform, thick, with a flat or concave base ; whorls 
keeled or stellated ; aperture angulated outside, brilliantly 
pearly ; operculum shelly. 

Distrihution, 20 species ? South Africa, India, Australia, 
New Zealand. 

Trochus, L. 
Etymology, trochus, a hoop. 

Synonyms, Cardinalia, Tegula, and Livona, Gray. Iiifundi- 
bulum, Montfort. Chlorostoma, Sw. Trochiscus, Sby. Monilea, 
Sw. 

Types, T. niloticus. PI. X., Eig. 5. T. zizyphinus. Eig. 114. 
Shell pyramidal, with nearly a flat base ; whorls numerous, 
flat, variously striated ; aperture oblique, rhombic, 
pearly inside; columella twisted, slightly trun- 
cated ; outer lip thin ; operculum horny, multi- 
spiral, Eig. 115 (T. pica). 

Animal with 2 small or obsolete head-lobes be- 
tween the tentacles ; neck-lappets large ; sides 
^" ^^'^' ornamented with lobes, and 3 — 5 cirri ; gill very 
tong, linear; lingual teeth 11, denticulated; uncini — 90, 
diminishing outwards^ 

* Fig. 114. Trochus zizyphinus, L., Pegwell Bay, Kent. 




GA.STEEOPODA. 265 

Disfrihution, 200 species. World-wide. Low water to 15 
fathoms ; tlie smaller species range nearly to 100 fathoms. 

Fossil, 361 species. Devonian — . Europe, North America, 
Chili. 

Sith-genera. Pyramis, Chemn., Tr. obeliscus. PI. X., Eig. 6. 
Columella contorted, forming a slight canal. 

Gihhula, Leach. Tr. magus, Britain. 

Shell depressed, widely umbihcated ; whorls tumid. Head- 
lobes largely developed ; lateral cirri, 3. 

Enida, Adams. 3 species, Japan. 

Margarita, Leach. Tr. helicinus. PL X., Pig. 7. 

Shell thin ; cirri, 5 on each side. 

Distribution, 17 species. Greenland, Britain, Falkland 
Islands. Near low water, under stones and sea-weed. 

Elenchus, Humphrey (= Canthiridus, Montfort) E. iris. PL 
X., Pig.. 8. Smooth, thin, imperforate, with a prominent base. 
Australia, New Zealand. F. Iris scarcely differs in form from 
Tr. zizyphinus; F. hadius is Uk.e a pearly phasianella; and 
F. varians (bankivia, Menke) would be called a chemnitzia, if 
fossilised. PL X., Pig. 9. 

Alcynus, Adams. 2 species, Japan. 

Minolia, Adams. 1 species, Japan. 

Turcica, Adams. 1854. 

Vitrinella, C. B. Adams, 1850. Shell minute, hyaline, 
turbiniform, umbilicated ; aperture large, orbicular. 

Distrihution, 18 species. West Indies (5), Panama. 

Photinida, H. and A. Adams, 1855. Shell heUciform ; spire 
somewhat acute. 

EoTELLA, Lamarck. 

Etymology, diminutive of rota, a wheel. 

Synonym, Helicina, Gray. 

Ty^e, E. vestiaria. PL X., Pig. 10. 

Shell lenticular, polished; spire depressed; base callous; 
lingual teeth 13; uncini numerous, sub-equal. 

Distribution, 15 species. India, Philippines, China, New 
Zealand. 

MoNODONTA, Lam, 

Etymology, monos, one, and odous (odontos), a tooth. 
Synonyms, Labio, Oken. Clanculus. Montfort, Olivia, Eisso. 
Types, M. labeo. PL X., Pig. 21. M. pharaonis. PL X., 
Fig. 12. 

Shell turbinated, few-whorled ; whorls spirally grooved and 

N 



266 MANUAL OF THE MOLLUSCA. 

granulated ; lip th.ickened internally, and grooved ; columella 
toothed, more or less prominently and irregularly ; operculum 
horny, many-wliorled. 

Distribution, 13 species ? West Africa, Eed Sea, India, 
Australia. 

Fossil (included with trochus), Devonian — . Eifel. 

Delphinula (Eoissy), Lam. 

Etymology, diminutive oi delphinus, sl dolphin. (= Cyclostoma, 
Gray !) 

Type, D. laciniata. PI. X., Pig. 13. (= T. delphinus, L.) 

Shell orbicular, depressed ; whorls few, angulated, rugose, or 
spiny ; aperture round, pearly ; peristome continuous ; um- 
bilicus open ; operculum horny, many-whorled. On reefs at 
low water. 

Animal without head-lobes ; sides lobed and cirrated. 

Distribution, 70 species. Eed Sea, India, Philippines, China, 
Australia. 

Fossil, 30 species ? Trias ? — ^Miocene — . Europe. 

Sub-genera. Liotia, Gray. L. gervillii. PI. X., Fig. 14. 
Aperture pearly, with a regular, expanded border ; operculum 
multi-spiral, calcareous. 

Distribution, 6 species. Cape, India, Philippines, Australia. 

Fossil, Eocene — . Britain, Prance. 

Collonia, Gray, 1850. C. marginata. PI. X., Pig. 15. 
Peristome simple ; operculum calcareous, with a spiral rib on 
the outer side. 

Distribution, Africa. 

Fossil, Eocene — . Paris. 

Cyclostrema, Marryat. C. cancellata, PI. X., Pig. 16. 

Shell nearly discoidal, cancellated, not pearly ; aperture round, 
simple ; umbiHcus wide ; operculum, spiral, calcareous. 

Distribution, 12 species. Cape, India, Philippines, Australia, 
Peru. In 5 — 17 fathoms. 

Serpularia, Ecemer, has the whorls smooth and disunited. 

Type, Euomphalus Serpula, Kon. Carb. Belgium. 
Crossostoma, Morris and Lycett. Columella toothed when 
young, concealed by callus in the adult. 2 species, Great 
oolite. 

Adeoebis, Searles Wood. 

Type, A. sub-carinatus. PI. X., Pig. 17. 
Shell minute, not nacreous, depressed, few-whorled, deeply 
Timbilicated ; peristome entire, nearly continuous, situated in 



GASTEEOPODA. 267 

its inner side, and slightly so externally ; operculum shelly, 
multi-spiral. 

Distribution, 6 species. "West Indies — China. Low water to 
00 fathoms. 

Fossil, 5 species. Tertiary — . Britain. 

EuoMPHALUS, Sowerby. 

etymology, eu, wide, and omphalos, umbilicus. 

Synonyms, Schizostoma, Bronn. StraparoUus, D'Orbigny. 
Ophileta, Yanuxem. Platyschisma, M'Coy. 

Type, E. pentagonalis. PI. X., Fig. 18. 

Shell depressed or discoidal ; whorls angular or coronated ; 
aperture polygonal ; umbilicus very large ; operculum shelly, 
round, multi-spiral. (Salter.) 

Fossil, 80 species, L. silurian— Trias. North America, Europe, 
Australia. 

Sub-genus. Phanerotinus, J. Sby. 1840, E. cristatus, Phil. 
Carb. limestone. Britain. 

Shell discoidal ; whorls separate ; outer margin sometimes 
foliaceous* 

Stomatella, Lam. 

Etymology, diminutiYC of stoma, the aperture. 

Type, S. imbricata. PI. X., Eig. 19. 

Shell ear-shaped, regular ; spire small ; aperture oblong, very 
large and oblique, nacreous; lip thin, even-edged; operculum 
circular, horny, multi-spiral. On reefs and under stones at 
ow water. 

Distribution, 33 species. Cape, India, North Australia, 
China, Japan, Philippines. 

Sub-genus ? Gena, Gray. Spire minute, marginal ; no 
operculum. 16 species. Eed Sea, India, Seychelles, Swan 
Biver, Philippines. (Adams.) 

Niphonia, Adams. 1 species, Japan. 

BuoDERiPiA, Gray. 

Etymology, named in honour of W. J. Broderip, Esq., the 
distinguished conchologist. 

Type, B. rosea. PI. X., Fig. 20. 

Shell minute, limpet- shaped, with a posterior sub-marginal 
apex ; aperture oval, as large as the shell, brilliantly nacreous. 

Distribution, 3 species. Philippines; Grimwood's Island, 
South Seas. (Cuming.) 

n2 



268 MANUAL OF THE MOLLL'SCA. 

Family X. — Haliotid^. 

Shell spiral, ear-shaped or trocliiforin ; aperture large, 
nacreous ; outer lip notched or perforated. No operculum. 

Animal with a short muzzle and subulate tentacles ; eyes on 
pedicels at the outer bases of the tentacles ; branchial plumes 
2 ; mantle -margin with a posterior (anal) fold or siphon, 
occupying the slit or perforation in the shell ; operculum lobe 
rudimentary ; lingual dentition similar to trochus. 

In addition to the true haliotids, we have retained in this 
group such of the trochiform shells as have a notched or per- 
forated aperture. 

Haliotis, L. Ear-shell. 

Etymology , hallos, marine, and ous [otos]^ an ear. 

Type, H. tuberculata, PL X., Fig. 21. 

Shell ear-shaped, with a small iiat spire ; aperture very wide, 
iridescent ; exterior striated, dull ; outer angle perforated by a 
series of holes, those of the spire progressively closed. Mus- 
cular impression horse-shoe shaped, the left branch greatly 
dilated in front. In H. tricostahs (padoUus, Montfort) the shell 
is furrowed parallel with the line of perforations. 

Animal with fimbriated head-lobes ; side-lobes fimbriated and 
cirrated; foot very large, rounded. Lingual teeth, median 
small ; laterals single, beam-like ; uncini about 70, with 
denticulated hooks, the first 4 very large. 

The haliotis abounds on the shores of the Channel Islands, 
where it is called the ormer, and is cooked after being well 
beaten to make it tender. (Hanley.) It is also eaten in Japan. 
It is said to adhere very firmly to the rocks with its large foot, 
like the limpet. The shell is much used for inlaying and other 
ornamental purposes. 

Distribution, 75 species. Britain, Canaries, Cape, India» 
China, Australia, New Zealand, Pacific, California. 

Fossil, 4 species. Miocene — . Malta, &c. 

Sub-genus ? Deridobranchus, Ehrenberg, D. argus, Eed Sea. 

Shell large and thick, like haliotis, but entirely covered by the 
thick, hard, plaited mantle of the animal. 

Stomatia (Helblin), Lamarck. 

Etymology, stoma, the aperture. 
Type, S. phymotis, PL X., Fig. 22. 

Shell like haliotis, but without perforations, their place being 
occupied by a simple furrow ; surface rugose, spirally ridged; 



GASTEROPODA. ■ 269 

spire small, prominent ; aperture large, oblong, outer margin 
irregular. 

Distribution^ 12 species. Java, Philippines, Torres Straits, 
Pacific. Under stones at low water. (Cuming.) 

Fossil, M. D'Orbigny refers to this genus 18 species, ranging 
from the L. Silurian to the chalk. North America, Europe. 

Teiwotis, H. and A. Adams, 1854. 

Shell depressed, elongated, ear-shaped ; spire small, and 
placed posteriorly; hinder part of the foot in the animal 
stretches far over the shell. 

Distrihution, 2 species. East India. 



SCISSTJIIELLA, D'Orbigny. 

Etymology, diminutive of scissus, slit. 

Type, S. crispata, PL X., Pig. 23. 

Synonyms, Anatomus, Montfort ; Woodwardia, Pischer. 

Shell minute, thin, not pearly ; body-whorl large ; spire 
small ; surface striated ; aperture rounded, with a slit in the 
margin of the outer lip ; operculate. The young have no slit. 

Animal like Margarita ; tentacles long, pectinated, with the 
eyes at their base ; foot with two 
pointed lappets and two long slender 
pectinated cirri on each side ; oper- 
culum ovate, very thin, with an 
obscure sub-spiral nucleus. 

No part of the animal was external 
to the sh^ll. The only living example 
occurred at Hammerfest, in 40 — 80 
fathoms water; when placed in a 
glass of sea-water it crawled up the 

side and scraped the glass with its "^'^- "6- ^'^i^'^^'^^^^- t- 
tongue. It was pale and translucent when living, but turned 
inky black after immersion in alcohol. (Barrett, An. Nat. Hist., 
2nd ser. vol. 17, p. 206.) 

Mr. Jeffreys found >S^. elegans (D'Orbigny) plentifully alive in 
sea-weed on the coast of Piedmont. It has a multi-spiral 
operculum, like Margarita. In this species, as noticed by Mr. 
Gr. Sowerby, the slit in the peristome of the young shell is 
converted into a foramen in the adult, as in the Jurassic 
Trochotoma. 

Distribution, o species. Norway, Britain, Mediterranean. In 




270 MANUAL OF THE MOLLTJSCA. 

7 fathoms water off tlie Orkneys, and in deep water east of tii3 

Zetland Isles. 

Fossil, 4 species. Tertiary — . Britain Sicily. 

Pleurotomaria, Defrance 

Etymology, pleura, side, and tome, notch. 
Type, P. anglica, PL X., Pig. 24. 

Shell trochiform, solid, few-whorled, with, the surface varioTisly 
ornamented ; aperture sub-quadrate, with a deep slit in its 
outer margin. The part of the slit which has been progressively 
filled up forms a band round the whorls. 

Distribution, 2 species. One occurs in deep water in West 
Indian seas. 

Fossil, 400 species. Lower Silurian — Chalk. North America, 
Europe, Australia. Specimens from clay strata retain their 
nacreous inner layers ; those from the chalk and limestones 
have lost them, or they are replaced by crystalline spar. 
Pleurotom.ari^ with wavy bands of colour have been obtained 
in the carb. limestone of Lancashire. In this extensive group 
there are some species which rival the living turbines in magni^ 
tude and solidity, whilst others are as frail as ianthina. 
Sub-genera. Scalites, Conrad, L. "Silurian, New York. 
Shell thin ; whorls angular, flat above (tabulated), 8 species, 
L. Silurian — Carb. 

Polytremaria, D'Orbigny, is founded on P. catenata 
(Koninck), in which the margins of the slit are wavy, converting 
it into a series of perforations. 

Catantostoma (clathratum) Sandberger, 1842. Shell like 
Fleurotomaria ; last whorl deflected, peristome incomplete, 
slightly varicose, irregular. Fossil, Devonian, Eifel. 

Baphistoma (angulata), Hall. L. Silurian, United States, 
Canada. Shell depressed, outer lip sinuated. In R. compacta 
(Salter) the spire is sunk and basin-shaped, the umbilical side 
fiat, and the last whorl a little disunited. 

MuECHisoNiA, D'Archiac, 

Etymology, named in honour of Sir Eoderick I. Murchison. 

Type, M. bilineata, PI. X., Fig. 25. 

Shell elongated, many-whorled ; whorls variously sculptured, 
and zoned like pleurotomaria ; aperture slightly channeled in 
front ; outer lip deeply notched. 

The murchisonice are characteristic fossils of the palaeozoic 



GASTEROPODA. 271 

rocks ; they have been compared to elongated pleurotomarice, 
or to cerithia with notched a]3ertures ; the first suggestion is 
most probably correct. 

Fossil, 50 species. L. Silurian — Permian. North America, 
Europe. 

Trochotoma, Lycett. 

Etymology, Trochus, and tome, a notch. 

Synonym, Ditremaria, D'Orbigny. 

Type, T. conuloides, PI. X., Pig. 26. 

Shell trochiform, slightly concave beneath; whorls flat, 
spirally striated, rounded at the outer angles ; lip with a single 
perforation near the margin. 

Fossil, 10 species. Lias — Coral Eag. Britain, Prance, &c. 

? Cirrus, Sowerby. 

Etymology, cirrus, a curl. 

Type, C. nodosus, Sby. Min. Con. t. 141 and 219. 

Shell sinistral, trochiform, base level ; last whorl enlarging 
rather more rapidly, somewhat irregular. 

Fossil, 2 species. Inf. oolite, Bath oolite. Britain, Prance. 

This genus was founded on a jpleurotomaria, a euomphalus, 
and C. nodosus. (v. Min. Con.) It is still doubtful what 
species may be referred to it. 




Fig. 117.* 

Iaj«"THINA, Lam. Yiolet-snail. 

Etymology, ianthina, violet-coloured. 

Type, helix ianthina, L. (I. fragilis, Lam.) PL X., Pig. 27. 

Shell thm, translucent, trochiform; nucleus minute, styhform; 
sinistral ; whorls few, rather ventricose ; aperture four-sided ; 
columella tortuous ; lip thin, notched at the outer angle. Base 
of the shell deep violet, spire nearly white. 

Animal head large, muzzle-shaped, with a tentacle and eye- 

* Pig. 117. Ianthina fragilis, Lam. (from Quoy and Gaimard). Atlantic, a, raft 
6, egg capsules ; c, gills ; d, tentacles and eye-stalks. 



272 MANUAL OF THE MOLLUSCA. 

pedicel on each side, but no eyes ; foot small, secreting a float 
composed of numerous cartilaginous air-vesicles, to the under 
surface of which the ovarian capsules are attached. Lingual 
ribhon, rachis unarmed ; uncini numerous, simple (Hke scalaria). 
Branchial plumes 2. Sexes separate. 

Distribution, 10 species. Atlantic, Coral sea. 

The ianthinae, or oceanic-snails, are gregarious in the open 
sea, where they are found in myriads, and are said to feed on 
the small blue acelephse [velella). They are frequently drifted 
to the southern and western British shores, especially when the 
wind continues long from the south-west ; in Swansea Bay the 
animals have been found quite fresh. When handled they 
exude a violet fluid from beneath the margin of the mantle. In 
rough weather they are driven about and their floats broken, or 
detached, in which state they are often met with. The capsules 
beneath the farther end of the raft have been observed to be 
empty, at a time when those in the middle contained young with 
fally formed shells, and those near the animal were filled with 
eggs. They have no power of sinking and rising in the water. 
The raft, which is much too large to be withdrawn into the shell, 
is generally thought to be an extreme modification of the oper- 
culum ; but M.. Lucaze-Duthiers, who has seen the raft formed, 
denies this. It is built up from glutinous matter secreted by 
the foot.* 

? Holopea (symmetrica), Hall. 184Y. Outer lip sinuated 
near the base. L. Silurian, New York. 

PAMILT XI. — FlSSTJRELLID^. 

Shell conical, limpet-shaped ; apex recurved ; nucleus spiral, 
often disappearing in the course of growth ; anterior margin 
notched or apex perforated ; muscular imj)ression horse-shoe 
shaped, open in front. 

Animal with a well- developed head, a short muzzle, subulate 
tentacles, and eyes on rudimentary pedicels at their outer bases; 
sides ornamented with short cirri; branchial plumes 2, sym- 
metrical ; anal siphon occupying the anterior notch or perforated 
summit of the shell. Lingual dentition similar to trochus.'f 

FissTJEELLA, Lam. Key-hole limpet. 

Etvmology, diminutive of fissura, a slit. 
Type, P. Listeri, PI. XL, Fig. 1. 

* Annales des Sciences Naturelles, 1865. 

t Fissurella is the best gasteropod for comparison with the bivalves ; its large gills, 
placed one on each side, and its sj'mmetrical shell, pierced with a median orifice for the 
escape of the out-going branchial current, are unmistakable indications of homologies 
with the lamelli-branchiata. See p. 39. 



GASTEEOrODA. 273 

Shell oval, conical, depressed, with the apex in front of the 
centre, and perforated ; surface radiated or cancellated; muscular 
impression with the points incurved. 

In very young shells the apex is entire and sub-spiral ; but as 
the perforation increases in size, it encroaches on the summit 
and gradually removes it. The key-hole limpets are locomotive ; 



^if^^^i 




Fig. 118. Fissurella. (Wilton.) 



they chiefly inhabit the laminarian zone, but range downwards 
to 50 fathoms. Eor dentition see Fig. 118. 

Distribution, 132 species. America, Britain, South Africa, 
India, China, Australia, Upper California, Cape Horn. 

Fossil, 30 species. Carb. ; oolites — . Britain and France, 

Sub-genera. Pupillia, Gray. F. apertura. Born. (=hiantula, 
Lam.) Shell smooth, surrounded by a sharp white edge ; per- 
foration very large. Distribution, South Africa. FissurelUdoea, 
D'Orbigny. F. hiantula. Lam. (=megatrema, D'Orbigny.). 
Shell cancellated ; covered by the mantle of the animal. 3 
species. Cape and Tasmania. 

{Macroschisma, Sw.) F. macroschisma, PI. XL, Fig. 2. 
Anal aperture close to the posterior margin of the shell. The 
animal is so much larger than its shell as to be compared to ther 
testacelle by Mr. Cuming. 

Distribution, Philippines and Swan Biver. 

Lucapina, Gray. F. elegans, Gray (==aperta, Sby.). Shell 
white, cancellated, margin crenulated ; eoveyed by the reflected 
mantle. 3 species. California. 



PiiNCTTniEiXA, Lowe, 

Synonyms, Cemoria, Leach. Diadora, Gray, 

Type, P. noachina, PL XL, Fig. 3. 

Shell conical, elevated, with the apex recurved ; perforation in 
front of the apex, with a raised border internally; sui'faee 
cancellated. 

Distribution, 6 (?) species. Greenland, Boreal Amerieay 

W 3 



274 MAKtTAL OF THE MOLLtTSCA. 

Norway, North Britain, Tierra-del-Fuego. In 20 — ^^lOt fathcmis 
Water. 

Fossil, in tlie glacial formations of North. Britain, 

ElMtTLA, Defrance. 

Etymology, diminTitiye of rima, a fissure. 

Synonym, Eimularia. 

Recent type, E. Blainvillii, PI. XI., Fig. 4. 

Shell thin and cajicellated, with a perforation near tlie anterior 
margin. 

Distribution, several species found on sandy mud at low water, 
or dredged in from 10 — 25 fathoms. Philippines (Cuming). 

Fossil, 3 species. Bath oolite— coral rag. Britain and Prance, 

EMAEGINtTLA, Lam. 

Etymology, diminutive of emarginata, notched. 

Type, E. reticula, PI. XI., Pigs. 5 and 6. 

Shell OYal, conical, elevated, with the apex recurved ;; surface 
cancellated ; anterior margin notched. Muscular impression 
with recurved points. The nucleus (or shell of the fry) is spiral, 
and resembles scissurella. The anterior slit is very variable in 
extent. The animal of emarginula (and also of puncturella) has 
an isolated cirrus on the back of the foot, perhaps representing 
the operculigerous lobe. (Forbes.) Lingual dentition, median 
teeth sub-quadrate ; laterals 4, oblong, imbricated ; uncmi about 
60, the first large and thick, with a lobed hook, the rest linear, 
with serrulated hooks. (Loven.) 

Distribution, 40 species. West Indies, Britain, Norway^ 
Philippines, Australia. Ean,ge from low water to 90 fathoms. 

Fossil, 40 species. Trias — . Britain and Prance. 

Sub-genus. Hemitoma, Sw. 

Type, E. octoradiata (E. rugosa, PI. XL, Figs. 7 and 8). 

Shell depressed, anterior margin slightly channeled. 

Parmophortts, Blainville, Duck's-bill limpet. 

Etymology, parme, a shield, and phoreus, a bearer. 

Type, P. australis, PL XL, Fig. 9. 

Synonym, Scutus, Montf. 

Shell lengthened- oblong, depressed ; apex posterior ; fronit 
margin arched. Muscular impression horse-shoe shaped, elon- 
gated. The shell is smooth and white, and permanently covered 
by the reflected borders of the mantle. The animal is black , 
and very large compared with the shell ; its sides are fringed 
with short cirri, and its eyes sessile on the outer bases of thick 



GASTEEOPODA. 275 

tentacles; it is found in shallow water, and walks freely. 
(Cuming.) 

Distribution, 15 species. New Zealand, Australia, Philippines, 
Singapore, Eed Sea, Cape. 

Fossil, 3 species. Eocene ? — . Paris Basin. 

Fahily XII. — Oaxyptejeid^. Bonnet-limpet. 

Shell limpet-like, with the apex more or less spiral ; interior 
simple, or divided by a shelly process, variously shaped, to 
which the adductor muscles are attached. 

A nimal with a distinct head ; muzzle lengthened ; eyes on the 
external bases of the tentacles ; branchial plume single. Lin- 
gual teeth single, uncini 3, as in Eig. 119, which shows dentition 




Fig. 119. Crepidula. (Wilton.) 

of crepidula. The rostrum is prominent and split, but non- 
retractile ; the median tooth hooked and dentate ; the first, or 
first and second laterals serrated, the third claw-shaped and 
simple. Loven places this family next to the Velutinidcs. 

The bonnet-limpets are found adhering to stones and shells ; 
most of them appear never to quit the spot on which they first 
settle, as the margins of their shells become adapted to the 
surface beneath, whilst some wear away the space beneath their 
foot, and others secrete a shelly base. Both their form and 
colour depend on the situation in which they grow ; those found 
in the cavities of dead shells are nearly fiat, or even concave 
above, and colourless. They are presumed to feed on the sea- 
weed growing round^ them, or on animalcules; a calyptrcea, 
which Professor Porbes kept in a glass, ate a small sea slug 
[goniodoris) which was confined with it. Both calyptrcea and 
pileopsis sometimes cover and hatch their spawn in front of their 
foot. (Alder and Clarke.) 

Dr. Gray arranges the bonnet-limpets next after the verme- 
tidse ; their lingual dentition is like velutina. 



276 MANUAL OF THE MOLLUSCA. 

Calypte^a, Lam. Cup-and-saucer limpet. 

Etymology, calyptra, a (lady's) cap. 

Synonym, Lithedaplms, Owen. 

Types, C. equestris, PL XI., Fig. 10. C. Dillwynnii, Pig. 11. 

Shell conical ; lim.pet-sliaped ; apex posterior, with a minute, 
spiral nucleus ; margin irregular ; interior with a half- cup 
shaped process on the posterior side, attached to the apex, and 
open in front. Surface rugose or cancellated. 

Animal with a broad muzzle ; tentacles rather short ; lanceo- 
late ; eyes on bulgings at the outer bases of the tentacles ; 
mantle-margin simple, sides plain. Pound under stones, be- 
tween tide-marks, and in shallow water. (Cuming.) 

Distribution, 50 species. West Indies, Honduras, Britain, 
Mediterranean, Africa, India, Philippines, China, Japan, New 
Zealand, Gallapagos, Chili. 

Fossil, 31 species. Carb. ? chalk — . Britain, Prance, &c. 

Sub-genera. Crucibulum, Schum. (Dispotsea. Say.,Calypeopsis, 
Less.) 

Example, C. rudis, PI. XL, Pig. 12. 

Shell spinulose ; internal cup entire ; attached by one of its 
sides. 

Distribution, West America, Japan, West Indies. Pound on 
shells, with its base worn, or smoothed by a shelly deposit. 
(Grray.) Between this section and the next there are several 
intermediate forms. 

Trochita, Schum. (Infundibulum, J. Sby., Galerus, Humph. 
Trochatella and Siphopatella, Lesson.) T. radians, PL XL, 
Pigs. 13, 14. (=Patella trochoides, Dillw.). T. sinensis, 
PL XL, Pig. 15. 

Shell circular, more or less distinctly spiral ; apex central ; 
interior with a more or less complete sub-spiral partition. 

Distribution, chiefly tropical, but ranges from Britain to New • 
Zealand. 

T. prisca (McCoy) is found in the carb. limestone in Ireland ; 
and several large species occur in the London clay and Paris 
basin. The recent C. sinensis — the "Chinaman's hat" of 
collectors — is found on the southern shores of England, and in 
the Mediterranean, in 5 — 10 fathoms water. (Forbes.) Its 
lingual dentition is given by Loven ; median teeth broad, 
hooked, denticulated ; uncini 3, the first hooked and serrated, 
2, 3, claw-shaped, simple. 

CREPrDTJLA, Lam* 
Etymology, crepidula, a small sandaL 



GASTEHOPODA. 277 

Type, 0. fornicata, PI. XI., Fig. 16. 

Synonym, Crypta, Humph. 

Shell oval, lunpet-like ; with, a posterior, oblique, marginal 
apex ; interior polished, with a shelly partition covering its 
posterior half. 

The crepidulce resemble the fresh- water naviceUce in form; 
but the internal ledge which mimics the columella of the nerite, 
is here the basis of the adductor muscles. 

They are sedentary on stones and shells, in shallow water, and 
are sometimes found adhering to one another in groups of many 
successive generations. The specimens or species which live 
inside empty spiral shells are very thin, nearly flat, and 
colourless. 

Distribution, 54 species. West Indies, Honduras, Mediter- 
ranean, West Africa, Cape, India, Australia, West America. 

Fossil, 14 species. Eocene- — . France, North America, and 
Patagonia. 

PiLEOPSis, Lam. Bonnet-limpet. 

Etymology, jpileos, a cap, and opsis, like. 

Synonyms, Capulus, Montf. Brocchia, Bronn. 

Type, P. hungaricus, PL XI., Pig. 17, P. militaris, PI. XI., 
Pig. 18. 

Shell conical ; apex posterior, spirally recurved ; aperture 
rounded ; muscular impression horse-shoe shaped. 

Animal with a fringed mantle-margin ; lingual teeth like 
calyptr<Ba. 

F. hungaricus (the Hungarian-bonnet) is found on oysters in 
5 to 15 fathoms water ; more rarely as deep as 80 fathoms, and 
then very small. P. milifiaris is extremely like a velutina. 

Fistrihution, 8 species. West Indies, Norway, Britain, 
Mediterranean, India, Australia, California. 

Fossil, 20 species. Lias — . Europe. 

Siib-genus. Amathina, Gray. A. tricarinata, PI. XL, Pig. 19. 

Shell depressed, oblong; apex posterior, not spiral, with 
three strong ribs diverging from it to the anterior margin. 

Flatyceras, Conrad (acroculia, Phil.). P. vetustus. Carb., 
linie>stone. Britain. 

Fossil, 20 species. Devonian — Trias. America, Europe. 

Metoptoma, Phillips. M. Pileus, Ph. 

Shell limpet-like, side beneath the apex truncated, resembling 
the posterior valve of a chiton. 7 species. Carb. limestone. 
Britain. 



278 MANUAL OF THE MOLLTTSCA. 

HiPPOiTS'X, Defrance. 

Etymology, hippos, a horse, and onyx, a hoof. 

Type, H. cornucopia, PL XI., Pigs. 20, 21. 

Shell thick, obliquely conical, apex posterior; base shelly, 
■with a horse-shoe shaped impression, corresponding to that of 
the adductor muscle. 

Distribution, 13 species. West Indies, Persian Gulf, Philij - 
pines, Australia, Pacific, "West America. 

Fossil, 10 sp. XT. chalk — . Britain, France, Korth America. 

Sub-genus. Amalthea, Schum. A. conica. Like hipponyx, 
but forming no shelly base ; surface of attachment worn and 
marked with a cresent-shaped impression. Often occurs on 
living shells, such as the large turbines and turbinell^o of the 
Eastern seas. 

Pamily XIII. — Patellid^. Limpets. 

Shell conical, with the apex turned forwards ; muscular im- 
pression horse-shoe shaped, open in front. 

Animal with a distinct head, furnished with tentacles, bear- 
ing eyes at their outer bases ; foot as large as the margin of the 
shell ; mantle plain or fringed. Eespiratory organ in the form 
of one or two branchial plumes, lodged in a cervical cavity ; or 
of a series of lamellae surrounding the animal between its foot 
and mantle. Mouth armed with horny upper jaw, and a long 
ribbon-like tongue, furnished with numerous teeth, each con- 
sisting of a pellucid base and an opaque hooked apex. 

The order cydo-hranchiata of Cuvier included the chitons and 
the limpets, and was characterised by the circular arrangement 
of the branchise. At a comparatively recent period it was ascer- 
tained that some of the patellse {acmcea) had a free, cervical 
gill ; whilst the chitons exhibited too many peculiarities to 
admit of being associated so closely with them. Professor 
Porbes has very happily suggested that the cyclo-branchiate 
gill of patella is, in reality, a single, long branchial plume, 
originating on the left side of the neck, coiled backwards round 
the foot, and attached throughout its length. This view is con- 
firmed by the circumstance that the gill of the sea-weed limpets 
{nacelloe) does not form a complete circle, but ends without 
passing in front of the animal's head. 

Patella, L. Pock limpet. 

Etymology, patella, a dish. 

Synonyms, Helcion Montfort ; Cymba, Adams. 



GASTEHOrODA. 



2.79 




Pig. 120, Patella 

vulgata. 
(Original, WiltOH.) 



Example^ P. longlcostata. PI. XL, Pig. 22. 

Shell oval, with, a sub-central apex; surface smootli:, or 
ornamented -with, radiating strise or ribs; 
ma.rgin even or spiny ; interior smooth. 

Animal with a continuous series of bran- 
chial lamellae ; mantle-margin fringed ; eyes 
sessile, externally, on the swollen bases of 
the tentacles ; mouth notched below. Lingual 
teeth 6, of which 4 are central, and 2 lateral; 
uncini 3. Pig, 120 shows the teeth, but not 
the uncini of P. vulgata. The Cape limpets 
(e.g. P. denticulaia) have a minute central 
tooth, which is wanting in any other species 
liitherto examined. (Wilton.) 

The dental canal of the common British 
limpet- (P. vulgata) is rather longer than its shell; it has- 160 
rows of teeth, with 12 teeth, in each row, or 1,920 in all. 
(Porbes.) The limpets live on rocky coasts, between tide-* 
marks, and are consequently left dry twice every day ; they 
adhere very firmly by atmospheric pressure (15 lbs. per square 
inch), and the difficulty of detaching them is increased by the 
form of the shell. On soft calcareous rocks, like the chalk of 
the coast of Th.anet, they live in pits balf an inch deep, pro- 
bably formed by the carbonic acid disengaged in respiration ; on 
hard limestones only the aged specimens are found to have worn 
the rock beneath, and the margin of their shell is often accom- 
modated to the inequalities of the surrounding surface. These 
circumstances would seem to imply that the limpets are 
sedentary, and liye on the sea-weed within reach of their 
tongues, or else that they return to the same spot to roost. On 
the coast of Northumberland we have seen them sheltering 
themselves in the crevices of rocks, whose broad surfaces, over- 
grown with nuUipores, were covered with irregular tracks, 
apparently rasped by the limpets in their between tides 
excursions.* 

The limpet is mucn used by fishermen for bait ; on the coast 
of Berwickshire nearly 12,000,000 have been collected yearly, 
until their numbers are so decreased that collecting them has 
become tedious. (Br. Johnston.) In the north of Ireland 
they are used for human food, especially in seasons of scarcity ; 



* If limpets are placed in stale water, or little pools exposed to the hot sun, they 
creep out more quickly than one would expect; the tracks Ihej' leave are very 
peculiar, and not likely to be mistaken when once seen. 



280 MANUAL OF THE MOLLUSCA. 

many tons weigh.t are collected annually near the town of 
Larne alone. (E. Patterson.) 

On the western coast of Soizth. America there is a limpet 
which attains the diameter of a foot, and is used by the natives 
as a basin. (Cuming.) 

The common limpet makes oval pits in timber as well as in 
chalk. Small individuals sometimes roost habitually on larger 
specimens, and make an oval furrow on the shell. The surface 
on which limpets roost, and some space around it, is often 
covered with radiating striae not parallel like those produced hy 
their teeth on nullipore. Mr. Gaskoin has a limpet-shell 
encrusted with nullipore, which other limpets have rasped all 
over. In M. D'Orbigny's collection of Cuban shells there is a 
^roup of oysters (0. cornucopice), with a colony of the Hipponyx 
mitrida sheltered in their interstices ; these limpets have not 
only fed on the nullipore with which the oysters are encrusted, 
but have extensively eroded the epidermal layer of shell 
beneath.* 

As to the CalyptrceidcE generally, although furnished witn 
lingual teeth (Fig. 96) like those of the animal-feeding Velutina, 
and themselves manifesting carnivorous propensities (p. 2Yo), it 
is difficult to understand how they can travel in quest of food. 

The shape of some species of limpet is believed to vary with 
the nature of the surface on which they habitually live. Thus 
the British Nacella pellucida is found on the fronds of the 
tangle, and assumes the form called N. Icevis, when in lives on 
their stalks. (Forbes.) The Acmcea testudinalis becomes 
laterally compressed and is called .4. alvea when it grows on the 
hlades of the Zostera (Gould) ; and Patella miniata of the Cape 
hecomes a new " genus " {Cyniha, Adams, not Broderip) when it 
roosts on the round stems of sea-weed, and takes the form 
cqIIqA P. compressa. (Gray.) 

Distribution, 144 species. Britain, Norway, &c. Wellington 
Channel. World-wide. 

Fossil, above 100 species of patellidee, including acmcea, L. 
Silurian — . North America, Europe. 

Sub-genera. Nacella, Schum. (= patina, Leach). 

Example, P. pellucida. PL XI., Fig. 23. 

Shell thin ; apex nearly marginal. 

Animal with the mouth entire below. Branchiae not con- 

* A similar circmnstance lias been noticed in the fresh- water Paludince and Am- 
pullaria, by Dr. Bland and Mr. E. Swift ; in the absence of other food thej^ devour the 
green vegetable matter incrnstirg one another's shells, and in doing tliis remove the 
epidermis, or even make holes in the shell. 



GASTEROrODA. 281 

tinued in front of the head. Found on the fronds and stalks of 
sea-weeds. Britain, Cape, CajDe Horn. 

Scutellina, Gray. S. crenulata. Shell with a broad margin 
internally. 7 species. Eed Sea, Philippines, Pacific, Panama. 
(Cnming.) 

AcM^A, Eschscholtz. 

etymology, acme, a 

Synonyms, Tectura, M. Edw. Lottia and Scurria, Gray, 
Patelloida, Quoy, 

Type, A. testudinalis. PI. XI., Fig. 24. 

Shell like patella. Animal with a single pectinated gill ; 
lodged in a cervical cayity, and exserted from the right side 
of the neck when the creature walks. Lingual teeth 3 on 
each side of the median line. Low water to 30 fathoms. 
(Forbes.) 

Distribution, 61 species. Norway, Britain, Australia, Pacific, 
West America. 

Sub-genera. Le^eta, Gray (= pro-pilidium, Forbes). Patella 
caeca, Miiller. 

/S/ieZ? minute, apex pos^enor. ^mma? blind. Britain. 30 — 90 
fathoms. 

Filidium, Forbes. P. fulva, Miiller. Britain. 20 — 80 fathoms 
water. 

Sliell small, apex anterior. Animal blind; gills 2, not 
projecting; mantle even-edged. Both lepeta and pilidium 
have large single median teeth, with trilobed hooks ; and 2 
hooked uncini on each side. 

Gadinia (Adanson), Gray. 

Type, G. peruviana. PI. XL, Fig. 26. 

Synonym, Mouretia, Sby. 

Shell conical; muscular impression horse-shoe-shaped, the 
right side shortest, terminating at the siphonal groove. 

Animal with a single cervical gill; tentacles expanded, 
funnel-shaped. 

Distribution, 8 species. Mediterranean, Bed Sea, Africa, Peru. 

Fossil, 1 species. Sicily. 

SiPHO]S"AiiiA, Sowerby. 

Ttjpe, S. sipho. PL XL, Fig. 25. 

Shell like patella; apex sub-central, posterior; muscular 
impression horse-shoe shaped, divided on the right side by a 



282 MANUAL or THE MOLLUSCA. 

deep siphonal groove, wliicli produces a sligM projection on the 
margin. 

Animal with, a broad head, destitute of tentacles ; eyes sessile 
on prominent rounded lobes ; gill ? single. The siphonarise 
are found between tide-marks, like limpets ; Dr. Gray places 
them with the pulmonifera, between the auriculidse and cycles- 
tomidse. 

Distribution, 41 species. Cape, India, Philippines, Australia, 
New Zealand, Pacific, Gallapagos, Peru, Cape Horn. (Cuming.) 

Fossil, 3 species. Miocene — . Prance. 



Family XIY. — Deisttaliad^e. Tooth-shells. 
Dentaolium, L. 

Ttjpe, D. elephantinum. PI. XL, Fig. 27. 

Shell tubular, symmetrical, curved, open at each end, 
attenuated posteriorly; surface smooth or longitudinally 
striated; aperture circular, not constricted.* 

Animal attached to its shell near the posterior anal orifice ; 
head rudimentary, eyes 0, tentacles ; oral orifice fringed ; 
foot pointed, conical, with symmetrical side-lobes, and an 
attenuated base, in which is a hollow communicating with the 
stomach. Branchiae 2, symmetrical, posterior to the heart ; 
blood red (Clarke) ; sexes united ? Lingual ribbon wide, 
ovate; rachis 1 -toothed; uncini single, flanked by single 
unarmed plates. 

The tooth-shells are animal-feeders, devouring foraminifera 
and minute bivalves ; they are found on sand, or mud, in which 
they often bury themselves. The British species range from 10 
— 100 fathoms. (Forbes.) 

Distribution, 50 species. West Indies, Norway, Britain, 
Mediterranean, India. 

Fossil, 125 species. Devonian — . Europe, Chili. 



Family XY.— Chitonidje, 

Chiton, L. 

Etymology, chiton, a coat of mail. 

Examples, C. squamosus, spinosus, fascicularis, fasciatus, PI. 
XL, Figs. 28—31. 

* D. gadus of Montagu is an annelid, belonging to the genus ditrupa. 



GASTEEOPODA. 283 

Shell composed of eight transverse imbricating plates, lodged 
in a coriaceous mantle, wMch forms an expanded margin round 
the body. The first seven plates have posterior apices ; the 
eighth has its apex nearly in front. The six middle plates are 
each divided by lines of sculpturing into a dorsal and two 
lateral areas. All are inserted into the mantle of the animal 
by processes (apophyses) from their front margins. The 
posterior plate is considered homologous with the limpet-shell 
by Dr. Gray ; the other plates appear like portions of its 
anterior slope, successively detached. The border of the mantle 
is either bare or covered with minute plates, hairs, or spines. 

Animal with a broad creeping disk like the limpet ; proboscis 
armed with cartilaginous jaws, and a long linear tongue ; 
lingual teeth 3 ; median small, laterals large, with dentated 
hooks ; uncini 5, trapezoidal, one of them erect and hooked. 
No ey-es or tentacles. Branchise forming a series of lamellae 
between the foot and the mantle, round the posterior part of 
the body. The heart is central , and elongated like the dorsal 
vessel of the annelides ; the sexes are united ; the re-productive 
organs are symnj.etrically repeated on each side, and have two 
orifices ; the intestine is straight, and the anal orifice posterior 
and median. 

Distribution. More than 250 species are known ; they occur 
in all climates throughout the world ; most abundant on rocks. 
at low water, but frequently obtained by dredging in 10 — 25 
fathoms. Some of the small British species range as deep as 
100 fathoms. (Forbes.) West Indies, Europe, South Africa, 
Australia, and New Zealand, California to Ohiloe. 

Fossil, 37 species. Silurian — . Britain, Belgium, &c. 

Sub-genera* Chiton. Synonyms, Lophurus, Poli. Eadsia, 
Callo-chiton, Ischno-chiton, and Lepto-chiton. (Gray.) 

Example, C. squamosus. PI. XI., Pig. 28. Border tessel- 
lated . 

Distribution, Brazil, West Indies, Newfoundland, Greenland, 
Britain, Mediterranean, Cape, Philippines, Australia, New 
Zealand, West America. 

Tonicia, Gray. C. elegans. Margin bare. 

Distribution, Greenland, Cape Horn, New Zealand, Valj)araiso. 

Acanthopleura, Guilding. C. spinosus. PI. XL, Fig. 29. 
Margin covered with spines, or elongated scales. 

* The sub-genera of Dr. Gray are founded on the form of the plates of insertion ; 
they are described in detail in the proceedings of the Zoological Society. Dr. 
Middendorf employs the number of the brancliial laminae for distinguishing the 
Bections. 



284 MANUAL OP THE MOLLUSCA. 

Synonyms., Scliizo-chiton, Coreplimin, Plaxiphora, Onyclio- 
cliiton, Enoplo-cliiton, Grray. 

Bistrihufiott, West Indies, Cape Horn, Falklands, Africa, 
Philippines, Australia, New Zealand, Yalparaiso. 

Mopalia^ Gray. C. Hindsii. Border haiiy. 

Distrihutio'n^ West America, Falkland Islands. 

KatharincL, Grray. C. tunicatus. Mantle covering all but 
tlie centre of the plates. 

Distribution^ New Zealand, West America. 

Cryptochiton, Gray, " Saw- dust chiton." C. amiculatus. 
Valves covered with scaly epidermis. 

Synonyms., Cryptoconchus, Sw. Amicula, Gray. 

Distribution, California. New Zealand. 

AcantJwcMtes^ Leach. C. fascicularis. PI. XI.. Pig. 30. 
Border ornamented with tufts of slender spines, opposite the 
plates. 

Distributimi, Britain, Mediterranean, New Zealand. 

Chitonellus, Lam. C. fasciatus, Quoy. PL XL, Pig. 31. 
Border velvety ; exposed portion of the plates small, distant ; 
apophyses close together. The dentition of chitonellus is repre- 
sented in Pig. 121. 

Distribution^ 10 species. West Indies, West Africa, Philip- 
pines, Australia, Pacific, Panama. The chitonellce are found in 
fissures of coral rock. (Cuming.) 

Fossil, Carh. Scotland. 

Oryphochiton, Gray. C. nervicanus. 

Sdminthockiton, Salter, 1847. H. Griflathii, Salter, Geological 

Fig. 121. Ckitonellus. Tasmania. ("Wilton.) 

Journal. Plates suh-quadrate, not covered bv the mantle : 
apophyses widely separated. 

Fossil, Silurian. Ireland. 

Brownia, Candei, D'Orbigny, 1853. A minute discoidal 
shell, associated with Helicophlegma in the first instance, but 
distinguished by the serrated keels on its whorls, and lateral 
notches to the aperture. Cuba. 

Calcarella, -spinosa, Souleyet, 1850. 

Shell sub-globose, dextrally spiral, horny, pellucid, with three 
acutely serrated keels ; aperture thickened, entire. Lateral 3 




GASTEEOPODA. 285 

lines. South Seas (= Echinos^Dira, Krohn and Jasonilla- 
Maed). 

Beduzia, Petit, 1853. R. JelLennei, Eed Sea. E, Eollandiana, 
Atlantic, and Mazatlan. 

Animal pelagic, resembling ianthina ; one inch long. 

Shell paludiniform, thin, with a brown epidermis ; whorls 
ventricose ; aperture oyate-oblique, slightly effused at the base, 
margins disunited ; inner lip oblique, rather sinuated in the 
middle ; outer lip acute, entire. 

These so-called genera, formerly thought to belong to the 
Atlantidse, are, for the most part, composed of prosobranchiate 
larvEe ; but the genera to which they belong has not yet been 
ascertained. 

OEDEE IL— PULMONIFEEA. 

This order embraces all the land-snails and other mollusca 
which breathe air. They are normal gasteropods, having a 
broad foot, and usually a large spiral shell ; their breathing- 
organ is the simplest form of lung, and is like the branchial 
chamber of the sea- snails, but lined with a network of 
respiratory vessels. One large division of the land-snails is 
furnished with an operculated shell ; the rest are in-operculatOy 
and sometimes shell-less. 

The pulmonifera are closely related to the plant-eating sea- 
snails (Jiolostomata), through Cyclostoma, and to the nudibrancJis 
by Oncidium. As a group, they are generally inferior to the 
sea-snails, on account of the comparative imperfection of their 
senses, and the union of the functions of both sexes in each 
individual. 

Sectioit a. — In-opeectilata. 

The typical pulmonifera vary much in appearance and habits, 
but agree essentially in structure. Most of them have suflB.- 
ciently large shells; in the slugs, however, the shell is small 
and concealed, or rarely quite wanting. Snail-shells contain a 
larger proportion of animal matter than sea-shells, and their 
structure is less distinctly stratified (p. 32). In form these 
shells represent many marine genera. The greater part are 
terrestrial, only some of the smaller families inhabit fresh 
waters or damp places near the sea. The respiratory orifice is 
small and valve-like,* to prevent too rapid desiccation in the 
land- snails, and to guard against the entry of water in the 
* Hence they are called Adelo-pneumona (concealed-lunged) by Gray. 



286 



MANTJAL OP THE MOLLUSCA. 



aquatic tribes. Land-snails are universally distributed; but 
the necessity for moist air, and the vegetable nature of their 
food, favour their multiplication in warm and humid regions : 
they are especially abundant in islands, whilst in hot and 
desert countries they appear only in the season of rain or dews. 
Their geological history is less complete than that of the purely 
marine orders ; but their antiquity might be inferred from the 
distribution of peculiar genera in remote islands, associated with 
the living representatives of the ancient fauna of Europe. 
Presh-water snails [Limnceidce] occur in the English Weald, 
but fossil land- snails have not been found in strata older than 
the tertiary in Europe, and then under forms generically, and 
even in one instance specifically, identical with living types of 
the New World [Megaspira, Proserpina, Glandina, and Helix 
labyrinthica). In the coal- strata of Nova Scotia Sir Charles 
Lyell has discovered a single specimen of a reversed and striated 
shell, apparently a Clausilia. 

The lingual dentition of the pulmonifera confirms, in a re- 
markable manner, those views respecting the affinities of the 
order, and its zoological value, which have been deduced from 
the more obvious characters afi'orded by the animal and shell. 
The operculated land-snails have seven-ranked teeth, like 
Paludina and Littorina. The in-operculated air-breathers 
have, without known exception, rows of very numerous, similar 
teeth, with broad bases, resembling tessellated pavement. Their 
crowns are recurved, and either aculeate or dentated. The 
lingual ribbon is very broad, often nearly as wide as it is long ; 
and the number of teeth in a row (though usually a third less) 
is sometimes as great, or even greater, than the number of 
rows. The rows of teeth are straight or curved or angulated ; 
when the rows are straight the teeth are simila.r in shape ; curves 
indicate gradual changes, and angles accompany sudden altera- 
tions of form. 







/^ilv!^! 



v/iOlvluNI^Mv/lvjIwh 



I ^ i e I 

Fig. 122. Lingual teeth of Achatina.* 



m 

ii 

■ vliUi 



The absolute number of teeth is only a specific character, and 
is usually greatest in the larger species ; but the Helicelke have 
fewer teeth in proportion than the Helices, and Yelletia has 

* Fragmeut of tlie lingual membrane of Achatina fulica, with central and lateral 
teeth more enlarged, from a specimen communicated by J. W. Laidlay, Esq. 



GASTEROPODA. 287 

fewer than Ancylus. The anomalous genus Amphihola (p. 139) 
is said to have a tongue, armed with teeth similar to those 
of the slug. 

About one-third the lingual membrane is spread over the 
tongue ; the rest has its margins rolled together, and is lodged 
in a sac or dental canal, which diverges downwards from the 
posterior part of the mouth, and terminates outside the buccal 
mass of muscles.* 

The mode in which the tongue is used, may be seen by placing 
a Limncea or Flanorhis in a glass of water, inside which the green 
conferva has begun to grow ; they will be observed incessantly 
cleaning off this film. The upper lip with its mandible is raised, 
the lower lip — which is horse-shoe shaped — expands, the tongue 
is protruded and applied to the surface for an instant, and then 
withdrawn ; its teeth glitter like glass-paper, and in Limncea it 
is so flexible, that frequently it will catch against projecting 
points, and be drawn out of shape slightly as it vibrates over 
the surface. 

"The development of the (in-operculate) Pulmonifera has 
been worked out by Yan Beneden and 'Windischmann,f by Oscar 
Schmidt, J and by Gegenbaur;§ the memoir by the last-named 
author, contains full information respecting Limax and Clausilia, 
and some important notices with regard to Helix. 

' ' The yelk undergoes complete division. The first stage of 
development consists in the separation of the embryo into 
mantle and foot. The anterior part of the body, in front of the 
mantle, dilates and forms a contractile sac — the homologue of 
the velum of marine gasteropods — which in Doris, Polycera, and 
^olis, has been seen to exhibit similar contractions. (Gegen- 
baur.) To this contractile vesicle the name of Yelk-sac was 
given by Yan Beneden and Windischmann, but it is a very 
different organ from the true Yelk-sac, which exists in the 
Cephalopoda alone among molluscs. 

"A similar contractile dilatation exists at the end of the foot 
— and the contractions of this ' caudal ' vesicle and of the 
' vitellary ' vesicle alternate, so as to produce a kind of circula- 
tion before the development of the heart. 

" The oral tentacles and parts about the mouth are the last to 
be completed. 

' ' A peculiar gland exists during the embryonic period, at- 

* Thomson, An. Nat. Hist. Feb. 1851. 

t Eecherches sur I'embryogenie des Limaces. Miiller's Archiv. 1841. 
t Ueber die Entwickelung von Limax agrestis. Miiller's Archiv. 1851. 
§ Beitrage zur Entwickelungsgeschichte der Land-gasteropoden. Siebold and 
KoJiker's Zeitschrift, 1852. 



288 majs^ual of the MOLirSCA. 

taclied. to tlie parietes of the ' yitellary ' vesicle, wMcli Gegenbaur 
and Sclimidt compare to a Wolffian body. 

*' Gegenbanr draws attention to the fact, that the first rudi- 
ment of the shell in Limax, Clausilia, and probably Helix, is not 
secreted on the exterior of the mantle, as in other gasteropoda ; 
but is deposited, in the form of calcareous granules, within its 
substance. 

*' Besides, therefore, the possession of Wolffian bodies, and of 
especial contractile organs, which subserve respiration and cir- 
culation during embryonic life — the terrestrial gasteropoda are 
further distinguished by the peculiar mode' of development of 
their shells — if the observations upon Clausilia and Helix may 
be extended to the rest. The first development of the shell 
within the substance of the mantle (a relation found hitherto 
only in the Cephalopoda) is up to the present time a solitary 
fact, without parallel among the other gasteropodous families." 
(Huxley.) 

Pamily I. — Helicid^.* Land-snails. 

Shdl external, usually well developed, and capable of con- 
taining the entire animal ; aperture closed by an epiphragm 
during hybernation. t 

Animal with a short retractile head, with four cylindrical, 
retractile tentacles, the upper pair longest and bearing eye- 
specks at their summits. Body spiral, distinct from the foot ; 
respiratory orifice on the right side, beneath the margin of the 
shell ; reproductive orifice near the base of the right ocular 
tentacle ; mouth armed with a horny, dentated, crescent-shaped 
upper mandible ; lingual membrane oblong, central teeth in- 
conspicuous, laterals numerous, similar. 

Helix, L.J 

Type, H. pomatia, L., Roman snail. 

Etymology , Helix, a coil. 

Shell umbilicated, perforated or imperforate ; discoidal, 
globosely-depressed or conoidal ; aperture transverse, oblique, 
lunar, or roundish ; margins distinct, remote, or united by 
callus. 

Animal with a long foot, pointed behind ; lingual teeth usually 
in straight rows, edge-teeth dentated. 

* The account of this family is chiefly taken from Dr. L. Pfeiffer's Monograpkia 
Heliceorum. 

t The epiphragm is a layer of hardened mucus, sometimes strengthened with car- 
bonate of lime ; it is always minutely pe.rfora' ed opposite the respiratory orifice. 

X The synonomy of the genus would fill several pages. See p. 48. 



GASTEROPODA. 289 

Distribution, including the gub-genera, above 1,600 species 
(several hundred species are ue described). World-wide ; rang- 
ing northward as far as the limit of trees, and southward to 
Tierra-del-Fuego, but most abundant by far in warm and humid 
climates. M. D'Orbigny obseived 6 species at elevations ex- 
ceeding 11,000 feet in South America, and Layard found H. 
gardeneri at the height of 8,000 feet in Ceylon. The species of 
tropical and southern islands are mostly peculiar. Several of 
the smaller British species, and even the large garden-snail {H. 
aspersa), have been naturalised in the most remote colonies. 
The Neapolitans and Brazilians eat snails. 

Fossil species about 200. Eocene — . Europe. 
Sections : Acavus, Montf. Shell imperforate. H. haemastoma, 
PL XII., Eig. 1. 

Geotrochus (lonchostoma) Hasselt, Trochiform, flat beneath. 
Polygyra, Say. Depressed, many-whorled. H. polygyrata, 
PI. XIL, Eig. 2. 

Tredopsis, Eaf. Aperture contracted by tooth-like projections. 
H. Hirsuta, PL XIL, Eig. 5. 

CarocoUa, Lam. Peristome continuous. H. lapicida, PL XIL, 
Tig. 3. 

Suh-genera. Anastoma, Eischer. (Tomigerus, Spix.) H. 
^lobulosa, PL XIL, Eig. 4. Aperture of adult turned up- 
wards, ringent ; 4 species. BrazL. 

Hypostoma (Boysii), Albers, is a minute Indian snail, in which 
the aperture is similarly distorted. 

Lychnus (Matheroni, Peq.) has a similar shell, but no apertural 
teeth ; 3 species occur in the Eocene Tertiary of South Erance. 
Streptaxis, Gray. H. contusa, PL XIL, Eig. 6. Sub-globose, 
lower whorls receding from the axis of the upper ; 34 species. 
Brazil, West Africa, Mascarene Islands, South Asia. 

Sagda, Beck. H. epistylium, PL XIL, Eig. Y. Imperforate, 
globosely conoid, close-whorled, aperture lamellate within, lip 
sharp ; 3 species. Jamaica. 

Proserpina (nitida), Guilding. Shell depressed, shining, 
callous beneath ; aperture toothed inside ; peristome sharp. 
Distribution, 6 species. Jamaica, Cuba, Mexico. 
Fossil, 'Eocene — . Isle of Wight. (E.Edwards.) 
Helicella, Lam.* Type, H. cellaria, PL XIL, Eig. 8. Shell 
thin, depressed; peristome sharp, not reflected. Lingual edge- 
teeth aculeate. 110 species. 
Stenopus (cruentatus), Guild. 

* For this group Dr. Gray formerly employed the name Zonites, given origintJI^ by 
Montfort to Helix Algira; in his later works he adopts ITeliceUa. 

O 



290 MANUAL OF THE MOLLTJSCA. 

Synonyms, Nanina (citrina), Gray; Arioplianta (laevipes, 
PI. XII., Pig. 9), Desm. 

Shell fhin, polished ; peristome thin , not reflected. 

Animal with the tail truncated and glandular, like Avion ; 
mantle-margin produced, partly covering the shell. 

Distribution, 295 species. South Asia and Islands, New Zea- 
land, Pacific Islands, "West Indies. 

Tanystoma (tuhiferum), Benson, 1856. Shell like Anastoma, 
minute, umbilicated; aperture disengaged, trumpet-like, 
toothed. Banks of the Irawadi, above Prome. 

Pfeifferia (micans), Gray, is a, Nanina without the mucus-pore 
at the tail. Philippines. 

YlTEnfA, Draparnaud. Glass-snail 

Type, V. Draparnaldi, PL XIL, Pig. 28. 

Synonym, Helicolimax, Per. 

Shell imperforate, very thin, depressed ; spire short, last whor 
large ; aperture large, lunate or rounded, columellar margin 
slightly inflected, peristome often membranous. 

Animal elongated, too large for complete retraction into the 
shell ; tail very short ; mantle reflected over the shell-margin, 
and furnished with a posterior lobe on the right side. Lingual 
teeth (of type) 100 rows of 75 each ; marginal teeth with a single 
long, recurved apex. (Thomson.) Occasionally animal-feeders, 
like the slugs. 

V. Cuvieri and Freycineti (Helicarion, Per.), tail longer, more 
abruptly truncated, with a caudal gland like arion, mantle moro 
developed. 

Distribution, 87 species. Most abundant in north part of the 
Old World. 

Sub-genera. Daudebardia, Hartm. (HeHcophanta, Per.) Y. 
brevipes, PI. XIL, Pig. 29. 

Shell perforated, horizontally involute; aperture oblique, 
ample. 8 species. Central Europe. 

Simpulopsis (sulculosa). Beck. 

Shell succinea-shaped. 5 species. Brazil. 

Stjccinea, Draparnaud, Amber-snail. 

Type, S. putris, PI. XIL, Pig. 23. 

Synonyms, Cochlohydra, Per. ; HeHsiga (S. Helenae), Less. ; 
Amphibulima (patula). Beck ; Pelta (Oumingii), Beck. 

Shell imperforate, thin, ovate or oblong ; spire smaU ; aperture 
large, obliquely oval ; columella and peristome simple, acute. 

Animal large, tentacles short and thick, foot broad ; lingual 



GASTEROrODA. 



291 



teetli like helix; S, putris has 50 rows of 65 teeth each. 
(Thomson.) Inhabits damp places, but rarely enters the water. 

Distribution, 155 species. World-wide. 

.Fossil, 1 species. Eocene. Britain. 

8uh-genus. Omalonyx, D'Orbigny. 0. "unguis, PI. XII., 
Fig. 24. 

Shell oval, convex, translucent, spire nearly obsolete, margins 
sharp. 

Animal large, slug-like ; shell placed on the middle of the 
back, with the mantle slightly reflected upon it all round. 

Distribution, 2 species. Bolivia, Juan Fernandez. 



BuLiMUS, Scopoli. 

Etymology ? Boulimos, extreme hunger (in allusion to its 
voracity !). 

Synonym, Bulinus, Brod. (not Adans). 

Tyve, B. oblongus, PI. XII., Fig. 10» 

Shell oblong or turreted ; aperture with the longitudinal 
margins unequal, toothless or dentate ; columella entire, revolute 
externally or nearly simple ; peristome simple or expanded 

Animal like Helix. B. ovatus attains a length of six inches, 
and is sold in the market of Eio ; it 
oviposits amongst dead leaves, the eggs 
have a brittle shell, and the young when 
hatched are an inch long. (See p. 44, 
Fig. 31.) 

Sections. Odontostomus (gargantuus), 
Beck, aperture toothed. 13 species. 
Brazil. 

Fachyotis, Beck (Caprella, Guild.), 
Fig. 123.* 

Fartula, Per. P. faba, PL XII., 
Fig. 13, Tahiti. 26 species. Asiatic, 
Australian, and Pacific Islands, South 
America. The animal is ovoviviparous. 

Gibbus [Lyonnetianus) Montf. 

Shell hump-backed. Mauritius, 2 
species. 

Bulimulus, Leach. B. decoUatus, PI. 




Fig. 12:\ 

XII., Figs. 11 and 12. 



Shell small, Hp acute. Above 300 species. England, 3 species. 

* Fig. 123. Bulimus auris-vu'pina, Chemn. The great extinct land-snail of St. 
Heliiia; fnm a specimen pr>.sented by Chas. Darwin, Esq. See "Journal of a Voyage 
rouuil the World." 

02 



202 * MAli^UAL OF THE MOLT-TJSCA. 

Zua, Leacli. Z. lubrica, PL XII., Fig. 14 

^liell polislied, columella sligMly truncated. 6 species. 

Azeca, Leach. A. tridens, PI. XII., Pig. 15. 

Stidl polislied, peristome thickened and toothed. 4 liying 
species. 

Distribution, 1,120 species. Universally distributed. 

Fossil, 30 Species. Eocene — . Europe, St. Helena, Australia, 
"West Indies. 

B. Guadalupensis occurs in modern limestone, with human 
remains. 

AcHATlisrA, Lamarck. Agate-shell. 

Type, A. variegata, PI. XII., Eig. 22. 

Synonyms, Cochlitoma, Per. Columna, Perry. Subulina 
(octona), Beck. Liguus (yirgineus), Montf. Cionella (acicula), 
Jeffreys. 

Shell imperforate, bulimiform ; columella twisted, and trun- 
cated in front ; aperture oval, angular above ; peristome simple, 
acute. , 

Animal snail-like. The great African Achatinse are the 
largest of all land-snails, attaining a length of eight inches; 
their eggs exceed an inch in length, and have a calcareous 
shell. 

Distrihution, 370 species. Europe, Africa, Asia, and tropical 
America. 

Fossil, 19 species. Eocene — . Europe and St. Helena. 

Sub-genera. Olandina (voluta), Schum. (Oleacina, Bolten; 
Polyphemus, Montf.) 

Shell oblong, fasiform ; aperture narrow, elliptical. 

Animal twice as long as the shell ; eye tentacles deflected at 
the tips, beyond the eyes ; vibracula much shorter, also deflected; 
lips elongated, tentacular. Prequents low and moist situations ; 
in confinement one refused vegetable food, but ate another 
snail. (Say.) 186 species. West Indies, Central America, 
Mexico, Plorida. 

Fossil. Eocene — . Olandina costellata. Isle of Wight. (P. 
Edwards.) 

Achatinella (vulpina), Sw. (Helicteres, Per.) Columella 
twisted into a strong, tooth-like fold. Sandwich Islands 25, 
Mariannes 2, Ceylon 1. 

Pupa, Lamarck. Chrysalis-shell. 

Type, P. Tiva. PL XII., Pig. 16. v 

Synonym, Torqailla duniperi), Studer. 



CrASTEEOPODA. 293 

Shell rimate or perforate, cylindrical or oblong; aperture 
rounded, often toothed ; * margins distant, mostly united by a 
callous lamina. 

Animal with, a short foot, pointed behind; lower tentacles 
short. 

Distvibution, 236 species. Greenland, Europe, Africa, India, 
Pacific Islands, North and South America. 

Fossil, 40 species. Garb. America. (Dawson.) Eocene — . 
Europe. 

Suh-genus. Vertigo, Miill. Y. Yenetzii, PI. XII., Pig. 17. 

Shell minute, sometimes sinistral. 

Animal with the oral tentacles rudimentary or obsolete, li 
species. Old World. 

Spiraxis, C. B. Adams, 1850. 

Type, Achatina anomala, Pfeiffer. 

Shell ovate-oblong, fusiform, or cylindrical; last whorl 
attenuated; aperture narrow, right margin usually inflected, 
columella more or less contorted, base scarcely truncated, fur- 
nished with a deeply-entering callous lamina. 

Distribution, 30 species. West Indies, Mexico, Juan Fer- 
nandez. 

Stenogyra, Shuttleworth, 1854. Shell elongated, turreted, 
many-whorled, semi-transparent, and blunt at the apex ; peri- 
stome simple ; shell frequently decollated. 

Animal somewhat like Bulimus; middle rachidian teeth small. 

Distribution, 50 species. Tropical America. 

Oylutohella, L. Pfeifi'er. Cylinder-snail. 

Tijpe, C. cylindrus, PI. XII., Fig. 20. f 
Synonyms, Brachypus, Guild. Siphonostoma, Sw 
Shell cylindrical or pupiform, sometimes sinistral, many- 
whorled, apex of the adult truncated, aperture round, peristome 
continuous, expanded. 

Animal similar to clausilia ; foot short, oral tentacles minute. 
Distribution, 143 species. West Indies, Mexico, Texas, South 
America. 

BALfeA, Prideaux 
Type, B. perversa. PI. XIL, Pig. 21. 
Synonym, Pusulus, Pitz. 

* Dr. Pfeiffer terms those teeth parietal -which are situated on the body-whorl, these 
on the outer lip -palatal, and on the inner lip columellar. 

t The figure is taken from a specimen in Mr. Cuming's cabinet, in whicli the 
empty apex, usually decollated, remains attached to the adult shell. 



294 MANUAL OF THE MOLLUSCA. 

Shell slender, usually sinistral, fusiform, multispiral, aperture 
ovate ; peristome acute, margins unequal, wall of the aperture 
■with, one single plait ; columella simple. 

Animal snail-like ; teeth 20.20 ; rows 130. (Thomson.) 

Distribution, 8 species. Norway, Hungary, New Granada, 
Tristan d'Acunha. The British species is found, very rarely, in 
Porto Santo, only on the highest peak, at an elevation of 1,665 
feet. (WoUaston.) 

Fossil, 1 species. Eocene. 

Sub-genus. Megaspira (elatior). Lea, PI. XII., Fig. 18. 

Shell dextral, with the columella transversely plaited. 

Distribution, 1 species. Brazil. 

Fossil, 1 species. Eocene — . Eheims. 

ToENATELLiNA, Beck. > 

Etymology, diminutive (or patronymic termination) of torna- 
tella. 

Type, T. bilamellata. Ant. 

Synonyms, Strobilus, Anton. Elasmatina, Petit, 

Shell imperforate, ovate or elongated ; aperture semi-lunar, 
margins unequal, disunited ; columella twisted, truncated ; 
inner lip 1 -plaited. 

Distribution, 27 species. Cuba, South America, Juan Fer" 
nandez, Pacific Islands, New Zealand. 

Paxilltjs, a. Adams. 

Type, P. adversus, Ad. Borneo. 

Shell small, pupiform, sinistral, rimate ; spire pointed ; aper- 
ture semi-ovate, ascending on the body- whorl ; inner lip 
spreading, 1 -plaited, outer lip expanded, notched in front. 

Clatjsilia, Draparnaud. 

Etymology, Diminutive of clausum, a closed place, 

Synonym, Cochlodina, Fer. 

Example, C. plicatula, Draparnaud (=C. Eolphii, Leach), 
PI. XII., Fig. 19. 

Shell fasiform, sinistral ; aperture elliptical or pyriform, con- 
tracted by lamellae, and closed when adult by a movable shelly 
plate {clausiwn) in the neck. 

Animal with a short, obtuse foot ; upper tentacles short, lower 
very small. G. bidens has 120 rows of 50 teeth ; 0. nigricans 
90 rows of 40 teeth each. 

Distribution, 386 species. Europe, Asia, Africa, and South 
America. 



GASTEROPODA. 



295 



Fossil, 20 species. Eocene — . Britain and France. Coal- 
strata, Nova Scotia. (Lyell.) 

C. maxima, Grat., Miocene, Dax, is two inches in length. 

Family II. — Limacid^. Slugs. 

Shell small or rudimentary, usually internal, or partly con- 
cealed by the mantle, and placed over the respiratory cavity. 

Animal elongated ; body not distinct from the foot ; head and 
tentacles retractile ; tentacles 4, cylindrical, the upper pair sup- 
porting eyes ; mantle small, shield-shaped ; respiratory and 
excretory orifices on the right side. 




Fig. 124. Limax Sowerbii, Fir. Brit. 

LiMAX, L. Slug. 

Type L. maximus. PL XII., Fig. 25. (L. cinereus, Miiller.) 

Shell internal, oblong, flat, or slightly concave beneath, 
nucleus posterior ; margin membranous ; epidermis distinct. 

Animal, foot pointed and keeled behind; mantle shield- 
shaped on the front of the back, granulated or marked with 
concentric striae ; respiratory orifice on the right side, near the 
posterior margin of the mantle ; reproductive orifice near the 
base of the right ocular tentacle ; lingual teeth tricuspid, those 
near the margin simple, aculeate. 

The slugs are connected with the snails by Vitrina; their teeth 
are similar, but have more elongated cusps. The creeping-disk or 
sole of the foot, extends the whole length of the animal ; but they 
frequently lift up their heads like the snails, and move their ten- 
tacles in search of objects above them. They often climb trees, and 
some can lower themselves to the ground by a mucous thread. 
When alarmed they withdraw their heads beneath the mantle, 
as in Fig. 124. Slugs feed chiefly on decaying vegetable 
and animal substances ; they oviposit at any time of the spring 
and summer when the weather is moist, and bury themselves in 
drought and frost. Limax nodilucus, Fer. (Phosphorax, Webb), 
found in Teneriff'e, has a luminous pore in the posterior border 
of the mantle. 



296 MANUAL OF THE MOLLUSCA. 

Bistrihution, 51 species. Europe, Canaries, Sandwicli Islands, 
Australia. 

Fossil, Eocene—. Britain. The Ancylus ? latiis, Edw., of 
tlie Isle of WigM, appears to be a Limax. 

Sub-genus. Geomalacus {maculosus) Allman. Ireland. 

Shell unguiform. Animal witli a mucus-gland at the 
extremity of the tail ; respiratory orifice near the right anterior 
border of the mantle. 

Afadeihts, Heynemann, 1863. 

Shell round, calcareous, nucleus posterior ; mantle large and 
rough ; respiratory orifice on the right side and near the 
middle of the mantle ; generatiye orifice distant from it behind 
the right tentacle. Dorsal surface not ridge 1; tail without a 
mucus-gland, and pointed. 

Distrihufion, 2 species. Himalayas. 

Incilaela, Benson. 

Type I. bilineata, Cantor, Chusan. 

Synonym ? Meghimatium, Hasselt. 

Animal elongated, tapering behind, entirely covered by a 
mantle ; tentacles 4, the upper bearing eyes ; the lower entire ; 
respiratory orifice on the right side, near the front of the mantle. 
Longitude 1^ inches. 6 species. North America, China. 

Philomycus (Eaf.) Eer. = Tebennophorus, Binney, 1842, 
Boston Society's Journal (Helix Carolinensis, Bosc) is also a 
slug with a long mantle. 

AmoN, Eerussac. Land-sole. 

Type, A. empiricorum, Eer. 

Synonym, Limacella, Brard. 

Shell oval, concave ; or represented by numerous irregular 
calcareous granules. 

Animal, slug-like ; respiratory orifice on the right side, 
towards the front of the mantle ; reproductive orifice imme- 
diately below it ; tail rounded, slightly truncated, terminated 
by a mucus-gland. Lingual teeth, as in Umax; A. empiricorum 
has 160 rows of 101 teeth each. The land-soles occasionally 
devour animal substances, such as dead worms or injured 
individuals of their own species. They lay 70-100 eggs between 
May and September, are 26-40 days hatching, and attain their 
full growth in a year ; they begin to oviposit a month or two 
before that period. The eggs of A, hortensis are very phos- 
phorescent for the first fifteen days. (Bouchard.) 



GASTEEOPODA. 297 

Distrihution^ 20 species. Europe. Norway, Britain, Spain, 

Poutli Africa. 
Fossil. Newer Pliocene, Maidstone. (Morris.) 
Pledropliorus [corninus^ Bosc) Fer. 5 species. Teneriffe ; 

represented as having a small conical shell on the tail ; probably 

an erroneous observation. 

Pahmacella, Cuvier. 

Type^ P. Oliyieri, Cuvier. 

Etymology i parma, a small shield. 

Synonym ? Peltella (Americana), Van Beneden, 

Shell concealedj oblong, nearly flat, apex sub-spiral. 

Animal vitrina-like, with an ample foot, pointed behind, and 
furnished with a mucus-pore ; mantle small, shield-like in the 
middle of the back, partly or entirely concealing the shell. 

P. caiyciilata, Sby. (Cryptella, Webb), PL Xll., Fig. 27, is 
patelliform, with an exposed papillary spire. 

Distribution, 7 species. South Europe, Canary Islands, North 
India. 

Janella, G-ray, 1850 (not Grat. 1826). 

Synonym^ Athoracophorus (!), Gould. 

Tyjje, Limax bitentaculatus, Quoy. Elongate, limaciform, 
covered by a mantle with free margins ; back grooved ; tentacles 
2, retractile, rising within the edge of the mantle ; respiratory 
orifice to the right of the dorsal groove, reproductive orifice 
below it and beneath the mantle. 

Distribution, New Zealand, on leaves. 

Akeitea, Gray, 1860. 

Mantle small and triangular, tooth strap with a single median 
tooth. 

Distribution, 1 species. A. Macdonaldii- New Hebrides, New 
Caledonia. 

PAEMARIOK, Fischer. 1855. 

SJiell shallow, partly external ; mantle large, with a free 
margin anteriorly, but covered by the shell posteriorly ; genera- 
tive orifice behind the right tentacle. 

Distribution, 4 species, India, 

Thibon-iophortts, Humbert, 1863. 

Mantle small, triangular, back with an almost imperceptible 
furrow ; teeth with wavy edges. 

Distribution, 3 species. New South Wales. 

3 



238 



MANtTAL OF THE MOLLtTSCA. 



ViQUESl^ELiA, Deshayes, 1857. 
Shell internal, rudimentary, oval, suborbicular, siiglitly con- 
cave below, and thickened at the edges ; summit sub-central. 




Fig. 125. Testacella haliotoides, Fer.* 

Testagella, Cuvier. 

Shell smallj ear-shaped ; situated on the posterior extremity 
of the body. 

Animal, slug-like, elongated and tapering towards the head ; 
back with two principal lateral farrows, from which numerous 
vein-like grooves ramify; mantle not larger than the shell; 
respiratory orifice on the right side, beneath sub-spiral apex of 
the shell; reproductive orifice behind the right tentacle. The 
Testacella is subterranean in its habits, feeding on earth-worms, 
and visiting the surface only at night. Its lingual membrane 
is very large and wide, with about 50 rows of 20.20 teeth, 
which diminish rapidly in size towards the centre ; each tooth 
is slender, barbed at the point, and slightly thickened at the 
base, and furnished with a projection on the middle of the 
posterior side. 








Fig. 126.t 

During winter and dry weather the Testacella forms a sort 

tn -..:^,^^^ of cocoon in the ground by the exudation 

s ^tt^ m/.^->v of its mucus. If this cell is broken, tho 

animal may be seen completely shrouded 

in its thin opaque white mantle, which 

rapidly contracts until it extends but a 

little way beyond the margin of the shell. 

Eig. 127. Testacella. ^[g^ 127 represents T. Maugei (lately 

* Back view of a half-grown individual ; side view of shell on the tail, and front 
view of the head. From specimens communicated by Arthur Mackie, Esq,., of Norwich. 

t Part of the lingual membrane of T. haliotoides, from a preparation by Fisher 
Cocken, Esq., of Botesdale. The dentition resembles that of Icmtluna. 




GASTESOFODA. 299 

fotind by Mr. Cunnington, in fields near Devizes), just dis- 
turbed from its sleep; s, the shell; m, the contracted 
mantle. 

Distribution^ 3 species. South Europe, Canary Islands, 
Britain (introduced). 

Fossil, 2 species. Tertiary. 

Family III.— Oncidiad^. 

Animal^ slug-like, destitute of any shell, completely coyered 
by a coriaceous mantle ; tentacles cylindrical, retractile, with 
eyes at their extremeties ; foot much narrower than the mantle 

Onciditim, Buchanan. 

Type, 0. TyphsB, Buch. 

Etymology, diminutive of onkos, a tubercle. 

Animal oblong, convex, usually tuberculated ; head with 2 
retractile tentacles, bearing the eyes ; mouth covered by a 
notched veil; no horny jaws; tongue broad, with above 70 
rows of lingual teeth (in 0. celticum), teeth 54.1.54;* the 
central teeth minute, triangular, with a single obtuse spine ; 
laterals slightly curved ; heart opistho -branchiate ; respiratory 
orifice posterior, distinct from the vent; sexes combined, ^ organ 
under the right tentacle, $ at the posterior extremity of the 
body. 

Bistrihution, 16 species. Britain, Mediterranean, Bed Sea, 
Mauritius, Australia, Pacific. 

The typical Oncidia live on aquatic plants in the marshes of 
the warmer parts of the Old World. Those which frequent 
sea-shores have been separated under the name Feronia, Bl. 
(Onchis, Fer). One species (0. celticum) is found on the coast 
of Cornwall, congregated in little groups, about a foot or two 
from the margin of the sea, where the waves break over them. 
They ascend and descend, so as to maintain their distance as the 
tides rise and fall ; but they will not bear long immersion in 
sea-water. (Couch.) 

? Buclianania {pncidioides). Lesson. Kamed after Dr. !F. 
Hamilton (Buchanan), the zoologist of India. 

Animal oval, entirely covered by a simple mantle ; respiratory 
orifice in the centre of the back ; head with 4 tentacles, retractile 

♦ Tliis is a convenient mode of stating the numbef of lin Hal teeth in each row ; it 
means that there is a single (symmetrical) tooth in the centre, and 54 lateral (im- 
sjTTmietrical) teeth on each side. If the numb r of rows of teeth on the dental mem- 
brane is known, it may be added below, thi s — Feronia Mavritiana, -^-^'gf^^ 



300 MAI'TUAL OF THE MOtLTTSCA. 

baneath. the mantle ; foot oval, miicli smaller than the mantle ; 
length 3^ inches. Coast of Chili. (Requires confirmation.) 

VAaiNULTJS, Eerussac. 

Type, Y. Taunaisii, Ferussac. 

Synonym, Yeronicella, Bl. 

Animal elongated, slug-like, entirely covered by a thick 
coriaceous mantle, smooth or granulated ; head retractile under 
mantle ; tentacles 4, upper pair slender, cylindrical, inflated at 
the tips and bearing eyes, lower pair short, bifid ; foot linear, 
pointed behind ; sexes united ; $ orifice behind the right ten- 
tacle, 2 midway on the right side, beneath the mantle ; 
respiratory and excretory orifices at posterior extremity between 
mantle and foot. Inhabits forests, in decayed wood and under 
leaves. 

Distribution, 20 species. West Indies, South America, India, 
Philippines. 

Family IY. — Limn^id^. 

Sliell thin, horn-coloured; capable of containing the whole 
animal when retracted ; aperture simple, lip sharp ; apex some- 
times eroded. 

Animal with a short dilated muzzle ; tentacles 2, eyes sessile 
at their inner bases ; mouth armed with an upper mandible, 
tongue with teeth similar to Helix. The Limnseids inhabit 
fresh waters in all parts of the world; they feed chiefly on 
decaying leaves, and deposit their spawn in the form of oblong 
transparent masses on aquatic plants and stones. They fre- 
quently glide beneath the surface of the water, shell downwards, 
and hybernate or sestivate in the mud. 

The fresh-water snails (and also Neritina) can lower them- 
selves from aquatic plants by a mucous thread, and re-ascend 
hy the same ; a Physa can be lifted out of the water by its thread. 

LiMW^A,* Lamarck. Pond-snail. 

Etymology, Limnaios, marshy. 

Type, L. stagnalis. Fig. 128. PI. XIL, Fig. 30. 

Shell spiral, more or less elongated, thin, translucent ; body-- 
whorl large, aperture rounded in front; columella obliquely 
twisted. 

Animal with a short, broad head ; tentacles triangular, com- 
pressed; lingual teeth {L. stagnalis) 55.1.55, about 110 rows', 
central teeth minute, laterals bicuspid, the inner cusp largest. 
* Adjectives employed as names for shells should have the feminine termitlation. 



GASTEEOrODA 



301 



L. peregra feeds on the green fresh-water algae ; L. sfagnalis 
prefers animal substances. 




Fig. 128. L. stagnalis. 

Distribution, 90 species. Europe, Madeira, India, Chinaj 
North. America. 

Fossil^ 70 species. Wealden — . Britain, Prance. 

Suh-genus. Amphijpeplea, Nilsson. A glutinosa, PL XII., 
Pig. 31. 

Shell globular, hyaline. 

Animal with a lobed mantle, capable of expansion over the 
shell. 5 species. Europe ; Philippines 




Fig. 129. C. pulchra. 

Chilikia, Gray. Chilian-snail. 

Mxample, 0. pulchra, D'Orbigny, Pig. 129 

Synonym, Dombeya, D'Orbigny. 

Shell oval, thin, ornamented with dark spots or wavy bands ; 
columella thickened, with one or two strong prominent folds. 

Distrihution, 18 species. South America ; in clear running 
streams. 

Fossil, 1 species. Miocene, Eio Negro, Patagonia. (B'Orb.) 

Physa, Draparnaud. 

Tijpe, P. fontinalis, PI. XII., Fig. 32. 

Etymology, Physa, a pouch. 

Synonyms, Bulin, Adans. Eivicola, Pitz. Isidora, Ehr. 



302 MAiOTAL OF i:aE mollttsca. 

Shell ovate, siniBtrally spiral, thin, polished ; aperture rounded 
in front. 

Animal with long slender tentacles ; the eyes at their bases ; 
mantle margin expanded and fringed with long filaments. 

P. hypnorum (Aplexa, Fleming) has an elongated spire, and 
the mantle margin is plain. 

Phy sepsis f Krauss, South Africa, has the base of the columella 
truncated. 

Camptoceras (terebras), Benson, India, has the whorls dis- 
united, and the peristome continuous. 

Distrihution, 20 species. North America, Europe, South 
Africa, India, Philippines. 

Fossil, 43 species. Wealden — . Britain, France. The largest 
living species (P. Maugerce, Ecuador ?) is 15 lines in length. A 
fossil species found at Grignon measures 26 lines, and another 
equally large occurs in India. 

AisrcYLTJS, Geofiroy. Eiver^limpet. 

Etymology, Ancylus (agkulos) a small round shield. 

Type, A. fluviatilis, Miiller. PL XII., Eig. 33 (Patella 
lacustris, L.). 

Shell conical, limpet-shaped, thin ; apex posterior, sinistral ; 
interior with a sub-spiral muscular scar. 

Animal like Limnsea ; tentacles triangular, with eyes at their 
bases; lingual teeth 37.1.37, in 120 rows, centrals small, laterals 
with long recurved hooks. 

Distrihution, 49 species. North and South America, Europe 
Madeira. On stones and aquatic plants in running streams. 

Fossil, 8 species. Eocene, Belgium, 

Sub-genera, Velletia (oblonga, Lightfoot), Gray. (Acroloxus, 
Beck.) 

Shell and Animal dextral • lingual teeth 40, in 75 rows. 3 
species. West Indies, Europe. 

Fossil, 2 species. Eocene. Britain, France. 

Latia, neritoides. Gray ; shell limpet-like, interior with a 
transverse plate, turned up and notched on one side. 2 species. 
Hew Zealand. 

Plaitoebis, Miiller. 

Synonym, " Coret," Adans. 
Type, P. corneus, PI. XII., Eig. 34. 

Shell discoidal, dextral, many-whorled ; aperture (irescentic, 
peristome thin, incomplete, upper margin projecting. 

Animal with a short, round foot; head short, tentacles 




GASTEROPODA. 303 

slender, tlie eyes at their inner bases ; lingual teeth snb-' 
quadrate, central and marginal bicuspid, laterals tricuspid ^ 
excretory orifices on left side of the neck. 

Some species of P/awor6ishaYe the sutures and spire deeply sunk, 
and the umbilicus flattened ; specimens occur -with 
the spire elevated (Fig. 130*). P contortus, a minute 
species, has above 6,000 teeth. (Cocken.) P. corneus 
secretes a purple fluid. (Lister.) P. lacustris (Seg- 
mentina, Fleming) has the whorls contracted inter- 
nally by periodic septa, 3 in a whorl, with triradiate 
openings. P. armigenus (Planorbula, Haldeman) Fig. 130. 
has 5 teeth in the aperture which nearly close the passage. 

Distribution, 145 species. North America, Europe, Itidiaj 
China. 

Fossil, 69 species. Wealden— . Britain, France. 

Gundlachia, ancyliformis, Pfeiffer, 1850. Fresh waters. Cuba, 

BTiell thin, obliquely conic; apex inclined posteriorly; base 
closed for two-thirds by a flat, horizontal plate ; aperture semi- 
circular. 

Family V.— -ArRicrLit)^. 

STidl spiral, covered with horny epidermis, spire short,, body* 
whorl large ; aperture elongated, denticulated ; internal septum 
progressively absorbed. 

Animal with a broad and short muzzle, tentacles, 2, cylin- 
drical, the eyes sessile behind them ; mantle-margin thickened ; 
orifices as in the snails ; foot oblong ; sexes united ; mouth 
with a horny upper jaw ; lingual teeth numerous, central series 
distinct, hooked, tricuspid. A. livida has about 31 laterals 
(Lovin) ; another species examined by Mr. Wilton has 11 
large laterals and about 100 smaller {uncini} on each side, 
gradually diminishing towards the edge (Fig. 131) : c, central 
teeth; I, laterals. 







Fig. 131. 

The Atiriculce frequent salt-marshes, damp hollows, and 
places overflowed by the sea; they were long regarded as 
marine animals, and their shells confused with those of 
Tornatella and Ringicula. 

* P> marginatus, var. Rochdale; colnmuflicated by J^ S. Gaskoili, Esq. 



S04 MAinJAl OF THE MOLLtTSCA. 

AuBICULA, Lamarck. 

Type, A. Jiidte. PL XII., Tig. 35. 

Etymology , Auricula, a Httle ear. 

Synonyms, Casaidula, Eer. (not Lam.). Mariniila (pepita) 
King. GeovTila, Sw. 

Shell oblong, with thick, dark epidermis ; spire obtuse ; aper- 
ture long, narrow, rounded in front, with 2 or 3 strong folds on 
the inner lip ; outer lip expanded and thickened. 

Distribution, 94 species. Philippines, Celebes, Feejees, Aus- 
tralia, Peru. 

Fossil, 28 species. ? Neocomian — . Prance. 




Fig. 132. A. auris--felis. (From Eyd. and Sotil.) 

A . Judce has truncated tentacles ; the typical species are met 
"with in the brackish-water swamps of tropical islands, on the 
roots of mangroves, and by small streams within the influ- 
ence of the tide. One species has been observed by Mr. Adams 
in nearly 2 fathoms water. 

Suh-^geyiera^ Polydonta, Fischer, P. scarahceus, PI. XIL, Pig» 
36. (Scarabus imbrium, Montfort). 

Shell oval, compressed; spire pointed, many-whorled, with 
lateral varices ; aperture toothed on both sides. 

Distribution, 34 species. India, Borneo, Celebes, Pacific- 
Islands. Inha,bits moist spots in woods near the sea, and is 
wholly terrestrial, feeding on decayed vegetables. (Adams.) 
1 Tertiary species. 

Dedipes (afra), Adans. 

Shell ovate, spirally striated, aperture denticulated on both 
sides ; the animal loops in walking, like truncatella. 

Distribution, West Indies, Africa, PhilippineSj Pacific Islands. 
Under stones on the sea-shore. 

Fossil, species. Eocene — . Brita,in, Erance. 

Co]!«"OYULTJS, Lamarck. 

Type, C. coniformis, Brug. PI. XII., Eig. 37. (-= Yoluta 
coiiea, L. ?) 
SynonyrM) Melampus, Montfort. Ehodostoma, Sw. 



GASTEROPODA. 305' 

Shell obtusely cone- shaped, smooth ; spire short, flat-whorled ; 
aperture long, narrow ; lip sharp, denticulated within ; colu- 
mella twisted in front ; wall of the aperture with 1 or 2 spiral 
plaits. 

Animal vdih. short, tapering, and rather compressed tentacles ; 
foot divided transversely into two portions, advanced successively 
in walking. 

Distribution, 56 species. "West Indies, Europe. In salt' 
marshes and on the sea-shore. The British species have thic 
ovate shells, with the spire moderately produced, and the aper- 
ture oval. They form the sub-genus Alexia (denticulata), 
Leach. 

Fossil, Eocene. Britain, France. 

Caeychitjm, Miiller. 

Type, 0. minimum, PI. XII., Eig. 39. 

Synonym, Auricella, Hartm. 

Shell minute, oblong, finely striated transversely; aperture 
oval, toothed, margin thickened, united by callus. 

Animal, with 2 blunt, cylindrical tentacles ; eyes black, 
sessile, near together, behind the tentacles. 

Distribution, 9 species. Europe ; North America. At the 
roots of grass in damp places, especially near the sea. 

Fossil, 3 species. Miocene — . Europe. 



The genus Siphonaria, described at p. 281, is supposed to be 
pulmoniferous, and to bear somewhat the same relation to 
Auricula that Ancylus does to Limnaea. The lingual dentition 
is similar to Auricula ; the centre teeth are distinct, the laterals 
numerous and hooked. 




Fig. 133.* 

Section B. — OPEECTJLATA.f 
The Operculated land-snails are exceedingly like periwinkles 

* Siphonaria species from the Cape ; three rows of teeth, c central, I laterals, from a 
preparation by J. W. Wilton. Esq., of Gloucester, 

t Phanera-pneumona (open-limged). Gray. The account of this group is chiefly 
taken from the catalogue prepared by my friend Dr. Baird. 



306 



MANUAL OF THE MOLLTJSCA. 



{littorince), and cliiefly differ from them in tlie situations they 
inhabit, and the medium respired. They have a long truncated 
muzzle, 2 slender contractile tentacles, and the eyes are sessile 
on the sides of the head.* The mantle-margin is simple, and 
the pulmonary cayity is situated on the hack of the neck, and 
quite open in front. Lingual ribbon narrow ; teeth 7 -ranked. 



^' 



/f^ 





Fig. 134. Lingual teeth of CydophorusA 

The sexes are distinct ; the shell is spiral, and closed by an 
operculum, presenting many beautiful modifications of structure 
characteristic of the smaller groups, which are often peculiar 
to limited regions, as in the Helicidce. The oldest fossil species 
are found in the Eocene Tertiary. 

Pamilt YI. — Cyclostomld^. 

Shell spiral, rarely much elongated, often depressed, spirally 
striated ; aperture nearly circular ; peristome simple. Oper- 
culum distinctly spiral. 

Animal with the eyes on slight prominences at the outer 
bases of the tentacles ; tentacles contractile only ; foot rather 
elongated. 

Cyclostoma, Lamarck. 

Etymology, Cyclos, circle, stoma, mouth. 

Type, C. elegans, PL XIL, Fig. 40. 

Synonym, Leonia (mammillaris) and Lithidion, Gray. 

Shell turbinated, thin, axis perforated: aperture oval; 
peristome continuous, simple, straight or expanded ; epidermis 
very thin. Operculum shelly, pauci-spiral. 

* The tentacles of the helicidce are retractile by inversion (p. 18), those of the 
cyclostomida are contractile only. 

t C. aquilum, Sby. (original). From a specimen gathered by J. W. Laidlay, Esq., 
on the steps of the great idol-temple of Mouhnein, Birmah. 



GASTEEOPODA. 3C7 

Animal witli clavate tentacles ; sole of the foot divided by a 
longitudinal groove, the side moved, alternatelv in walking; 
the end of the long muzzle is also frequently applied, as by the 
looping-snails (Truncatellse), and used to assist in climbing. 




Fig. 1S5. Cydostoma elegans, from Charlton, Kent. 

Distribution, above 160 species. South Europe; Africa, 
Madagascar. The only British species, C. elegans, is found on 
calcareous soils ; it ranges to the Canaries and Algeria, and 
occurs fossil in the newer Tertiaries. Nearly half the species 
have the whorls spirally keeled, and have been distinguished 
under the name TropidopJwra by Troschel. They are found 
in Madagascar and the adjacent islands and coast of Africa. 

Fossil, 40 species. Eocene, Europe. 

Suh-genera. Otopoma, foliaceum, Gray. Shell sub-globose, 
umbilicated ; peristome with an ear-like process covering part 
of the perforation. Distribution, 15 species. Arabia, Mada- 
gascar, China, New Ireland. 

Ohoanopoma, lincina, Pfeiffer. Shell often a little decollated ; 
peristome usually double, the outer edge angularly expanded. 
Lincina (labeo), Br., has the last whorl produced. Jamaicia 
(anomala), C. B. Adams, has the operculum convex. Distribution, 
VO species. "West Indies, and a few in Tropical America. 

Oistula (fascia), Gray. = Tudora, megacheila. Gray. Shell 
ovate or elongated, apex usually decollated, peristome free; 
operculum with a thin shelly outer coat. Chondropoma, semi- 
labre, Pfr,, diflPers in the operculum being " sub-cartilaginous.'* 
Distribution, about 70 species. West Indies; Tropical America, 
8 species. 

Bealia, hieroglyphica, Gray. ^ Hydrocsena (part) Parreyss, 
Omphalotropis, Pfr. Liarea (Egea), Gray. Bourciera, helicinae- 
formis, Pfr. Shell turreted or turbinate, perforated ; peristome 
simple, straight or expanded; operculum pauci-spiral, horny. 
Distribution, 17 species. Canaries, ? Mauritius, Pacific Islands. 
(Ecuador, Bourciera.) 

Pomatias, maculatum, Studer. Shell slender, transversely 
striated; peristome reflected; operculum cartilaginous, con- 



308 MANUAL OF THE MOLLFSCA. 

camerated ■within. Distribution, 18 species. South Europe ; 
Corfu, India. 

Adamsiella (mirabilis) Pfeiffer, 1851 = Choanopoma, Pfr. 
(part) 1847. " Operculum thin, rather cartilaginous." Bistrihu- 
tion, 12 species. Jamaica, Demerara. Named after the late 
Professor C. B. Adams, of Amherst, Massachusetts. 

Cyclotoj)sis, Blanford. Asia. 

PFerussina, Grateloup. 

Etymology, named in honour of Baron Perussac. 

Type, P. anastomseformis, Gr. 

Synonym, Strophostoma, Desh. 

Shell rounded, depressed, umbilicated ; whorls transversely- 
striated above, spirally keeled below ; aperture turned obliquely 
upwards, peristome simple. Operculum. ? 

Fossil, species. Miocene — . Dax ; Turin. 

Cyclophoeus, Montfort. 

Etymology, Cyclos, circle, phoreus, bearer. 

Type, 0. involutus, PI. XIL, Pig. 41. 

Shell depressed, openly umbilicated ; aperture circular ; 
peristome continuous, straight or expanded ; epidermis thick ; 
operculum horny, many-whorled. 

Animal with long, slender pointed tentacles; foot broadly 
expanded, not grooved. 

Distribution, about 150 species. India, Philippines, New 
Zealand, Pacific Islands, Tropical America. 0. gibbus, Per. 
(Alycaeus, Gray), has the last whorl distorted. C. cornu-vena^ 
torium, Sby. (Aulopoma, Troschel), Ceylon, has the peristome 
free when adult ; the operculum is larger than the aperture, 
and reflected over it. 

Sub- genera. Fterocyclos (rupestris), Benson. Myxostoma and 
Steganostoma, Troschel. Shell depressed, nearly discoidal, 
widely umbilicated ; peristome expanded, produced into a little 
wing at the suture; operculum sub -cartilaginous, spirally 
lamellated. Distribution, 16 species. India, Ceylon, Birmah,, 
Borneo ? 

Cyclotus (fuscescens), Guildin^ (Aperostoma, Troschel). Shell 
depressed, widely umbilicated; operculum shelly, whorlsi 
numerous, with raised margins. Distribution, 44 species. West 
Indies, Tropical America, India, Asiatic Islands. Fossil, Eocene, 
Isle of Wight. (P. Edwards). 

Lcptopoma (perlucidum), Pfeifler. Shell turbinated, peristome 
si uple, reflected ; operculum membranous. Distribution, 20 



GASTEROPODA. 309 

species. PLilippines, India, New Guinea, New Zealand, Pacific 
Islands. 

Lomastoma* (cylindracenm), Guild. (Farcimen, Troseliel.) 
Shell oblong or pupa-shaped, scarcely perforated, aperture 
circular ; operculum thin, horny, many-whorled, flat. Distri- 
hutio7i, 19 species. West Indies, Tropical America, Canaries, 
India, Mauritius. Fossil, Eocene — . Paris and Isle of "Wight. 
(E. Forbes.) 

Craspedopoma (lucidum), Pfr. Shell turbinate, rimate, a little 
contracted near the aperture ; operculum round, horny, many- 
whorled. Distribution, 3 species. Madeira, Palma. Fossil, 
Eocene — . Isle of Wight, Madeira. 

Cataulus (tortuosus), Pfr. Shell pupa-shaped, with the base 
keeled, producing a channel in the front of the aperture ; oper- 
culum circular, horny, the whorls easily separable. Distribu- 
tion, 6 species. Ceylon. 

Diplommatina (folliculus), Benson. Shell minute (1 species 
sinistral), conical, with costulated whorls ; peristome double ; 
operculum horny, multi-spiral. Distribution, 3 species. India. 

Opisthophorus, Benson, 1855. 0. biciliatus, Mouss. Shell 
like Fterocydos ; operculum double, margin grooved, interior 
concamerated. Distribution, 4 species. Singapore, Borneo^ 
Java. 

Hybocystis, Benson, 1859. Shell distortedly o\ate; aperture 
circular, interior peristome deeply notched. Operculum shelly, 
thick, multi-spiral. 

PupiiSTA, Yignard. 

Type, P. bicanaliculata, Sby. PI. XII., Fig. 42. Australian 
Islands. 

Shell sub -cylindrical, usually polished; aperture circular,, 
peristome thickened, notched in front and at the suture ; oper- 
culum membranous, narrow- whorled. P. grandis, Forbes, has 
a dull epidermis. 

Distribution, 17 species. Philippines, New Guinea, New Ire- 
land, Louisiades. 

Sub-genus, Rhegostoma (nunezii), Hasselt. Aperture with a 
narrow channel in the middle of the columellar side. 6 species, 
Philippines, Nicobar. In R. Lubricum (Callia, Gray) the sinus 
is obsolete. R. pupiniforme (Pupinella, Gray) is perforated, 
and has a dull epidermis. 

* Abridged from Megaloma- stoma ; Swainson, who judiciously curtailed several 
preposterously long names, allowed this to remain. 



310 MAinJAL OF THE M0LLT7SCA 

Helicina, Lamarck. 

Type, H. Neritella, liam. 

Synonyms, Oligyra, Say. Pachytoma, Sw. Ampultina, Bl. 
Pitonillus, Montfort. 

ISliell globose, depressed or keeled, callous beneatli ; aperture 
squarish, or semi-lunar ; columella flattened ; peristome simple, 
expanded ; operculum shelly or membranous, squarish, or semi* 
ovate, lamellar. 

Animal like Cyclophorus ; lingual teeth. 3.1.3. (Gray.) 

Distribution, 162 species. West Indies, Tropical America, 
Pacific Islands, Australian Islands, Philippines. 

Sub-gen-era. Lucidella (aureola), Grray. Peristome more or 
less toothed internally. 8 species. West Indies, Tropical 
America. 

Trochatella (pulchella), Sw. Shell not callous beneath. ; peri- 
stome simple, expanded. West Indies 20 species, Venezuela 1. 

Alcadia, Gray. A. Brownei, PI. XII., Fig. 43. Jamaica. 
Shell helix-shaped, often velvety, callous beneath ; columella 
flattened, straight; peristome slit in front; operculum shelly, 
semi-ovate, with, a tooth-like process adapted to the slit in the 
peristome. Distribution, 17 species. Cuba, Jamaica, and Hayti. 

Stoastoma, C. B. Adams. 

Etymology, stoa, pillared, stoma, mouth. 

Type, S. pisum, Ad. 

Shell minute, globose-conic or depressed, spirally striated; 
aperture semi-oval ; peristome continuous ; inner margin 
straight, forming a small spiral keel round the umbilicus; 
operculum shelly, lamellar. 

Distribution, 19 species. Jamaica. S. succineum (Electrina, 
Gray) has smooth whorls. I. Opara, Polynesia. 60 new species 
bave been added by the Hon. E. Chitty, who divides them 
among several new genera. 

Family YII. — Aciculid^. 

Shell elongated, cylindrical ; operculum thin, sub-spiral. 

Animal with the muzzle rather produced, slender and trun- 
cated ; eyes sessile on the upper part of the head, behind the 
base of the slender tentacles ; foot oblong, short, pointed 
behind. 

AcicuLA, Hartmann. 
O'ype, A. ftisca, PI. XII., Fig. 44. 



GASTEROPODA. 311 

Synonym, Acme and Acmaea, Hartmanii.* 

Shell minute, slender, nearly imperforate ; peristome slightly 
thickened, margins sub-parallel, joined by a thin callus ; oper- 
culum hyaline. 

Distribution, 1 species. Britain, Germany, France ; Yanicoro 
(on leaves). A, fusca is found in low, marshy situations, at the 
roots of grass ; it occurs fossil in the Newer Pliocene of Essex. 
(J. Brown.) 

Geomelania, Pfeiffer. 

Type, G. Jamaicensis, Pfeiffer. 

Etymology, Ge, the ground {i.e. terrestrial). 

Shell imperforate, turreted ; aperture entire, effused ; peri- 
stome simple, expanded; margins joined, basal produced into a 
tongue-shaped process ; operculum oval, pellucid, whorls few, 
rapidly enlarging. 

Distrihution, 21 species. Jamaica. 

Order III. — Opistho-brajstchiata. 

Shell rudimentary or wanting. Branchice arborescent or 
fasciculated, not contained in a special cavity, but more or less 
completely exposed on the back and sides, towards the rear 
[opisthen) of the body. Sexes united. (M. Edwards.) 

The moUuscs of this order may be termed sea-slugs, smce 
the shell, when it exists, is usually small and thin, and wholly 
or partially concealed by the animal. When alarmed or 
removed from their native element, they retract their gills and 
tentacles, and present such a questionable shape that the inex- 
perienced naturalist will be likely enough to return them, with 
the refuse of the dredge, into the sea. Their internal structure 
presents many points of interest ; in some the gizzard is armed 
with horny spines, or large shelly plates ; in others the stomach 
is extremely complicated, its ramifications and those of the 
liver being prolonged into the papillae, which are said to be 
branches of the respiratory organ. The tongue is always armed, 
but the number and arrangement of the lingual teeth is ex- 
ceedingly variable, even in the same family ; usually the dental 
membrame is broad and short, with many similar teeth in each 
row. 

The lingual dentition is extremely varied in the BuUidoe. In 

* All given in the same year, 1821, the name Acmaea having been employed by 
Eschscholtz for a genus of limpets ; Acicula has been retained bv Pfeiffer and Gray 
for this land-shell. 



312 



MANUAL OP THE MOLLTJSCA. 



Philine aperta tliere is no central tooth ; and the laterals, which 
increase rapidly in sis^e backwards, have a finely denticulated 
membranous inner edge. 

In Tornatella and Bulla (physis) the rachis is unarmed, and 

the lateral teeth are nume- 



/2=^ 




Fig. 136. Philine aperta. (Wilton.) 



reus and similar ; in Acera, 
Cyliclini, and AmjpMsphyra 
there is a minute central 
tooth. 

The alimentary canal ter- 
minates more in the rear of 
the body than in the other 
univalve shell-fish.* The 
gills are behind the heart, 
and the auricle behind the 
ventricle ; conditions which 
characterise the embryonic 



state of the moUusca generally. 

Comparatively little is known of the geographical distribution 
of these animals ; they have been found wherever the requisite 
search has been made, and are probably much more numerous 
than at present estimated. Considerable additions, however, 
have been made to our knowledge on this subject by the 
researches of Kelaart in Ceylon and A. Adams in the Chinese 
seas. The shell-bearing genera flourished in the period when 
the secondary strata were deposited. The living species are 
chiefly animal-feeders, preying on other shell-fish and on 
zoophytes. 

Sectio]!^ a. — Tecti-brajstchiata.-j* 

Animal usually provided with a shell, both in the larval and 
adult state ; branchiae covered by the shell or mantle ; sexes 
united. 

FAMIIiY I. — TORlJiTATELLID^. 

Shell external, solid, spiral or convoluted ; sub-cylindrical ; 



» In the cuttle-fishes and pteropods it is bent upon itself ventrally, in the sea-snails 
dorsally, terminating in front, near its origin ; the vascular system partakes of this 
flexure, and the gills are in advance of the heart. (Huxley.) 

t Mono-pleuro-branchiata. Bl. Pomato-branchia, (from poma, a lid). Wiegm. 
The order Tecti-branchiata of Cuvier included only the family JBullidce ; it is here 
made to comprise the Infero-branchs also ; no object being gained by the multiplica- 
tion of descriptive epithets. 



GASTEROPODA. 313 

aperture long and narrow; columella plaited; sometimes 
operculated. 

Animal with a flattened, disk-like head, and broad obtuse 
tentacles ; foot ample, furnished with lateral and operculigerous 
lobes. 

The shells of this family are chiefly extinct, ranging from the 
period of the coal strata, and attaining their greatest develop- 
ment in the cretaceous age. Tornatella is essentially related to 
Bulla, but presents some resemblance to the FyramidelUdce in 
its plaited and operculated aperture ; in Tornatina the nucleus, 
or apex, is sinistral. The spiral striae which ornament many 
of the species are punctate, as in the Bullidae ; and the outer 
lip often remarkably thickened, as in Auricula. 

Tornatella, Lamarck. 

Type, T. tornatilis, PI. XIY., Fig. 1. 

Synonyms, Actseon, Montf. (not Oken), Dactylus (solidulus), 
Schum. ? Monoptygma (elegans), Lea. 

Shell solid, ovate, with a conical, many-whorled spire ; 




Fig. 137. 

spirally grooved or punctate-striate ; aperture long, narrow, 
rounded in front ; outer lip sharp ; columella with a strong, 
tortuous fold ; operculum horny, elliptical, lamellar. 

Animal white ; head truncated and slightly notched in front, 
furnished posteriorly with recumbent tentacular lobes, and 
small eyes near their inner bases; foot oblong, lateral lobes 
slightly reflected on the shell. Lingual teeth 12.12, similar, 
with long simple hooks. 

Distribution, 16 species. United States, Britain, Senegal, 
Eed Sea, Philippines, Japan, Peru. T. tornatilis inhabits deep 
water — 60 fathoms. (Porbes.) 

jFoss'i7, 70 species. Trias — Lias— ^. North America, Europe, 
South India. 

Sub-genera. Cylindrites (Llhwyd), Lycett. 0. acutus, Sby. 
PI. XIY., Pig. 2. (A.) Shell smooth, slender, sub -cylindrical, 
spire small, aperture long and narrow, columella rounded, 

P 



314 MANUAl OF THE MOLLUSC A. 

twisted, and directed slightly outwards. (B.) Shell oval, spire 
sunk, whorls with acute margins. Bath Oolite, Britain. 

Acteonina, D'Orbigny. Tornatellse "without columella 
plaits," 30 species. Garb. — Portlandian (including Cylindrites). 

Adeonella, D'Orbigny. A. Eenauxiana, PI. XIV., Fig. 3. 
Shell thick, cone-like or conyoluted, spire short or concealed, 
aperture long and narrow, columella with 3 strong and regular 
spiral plaits in front. Distribution, 18 species. Chalk ; Britain, 
Trance. 

Adeon Oahanetiana, D'Orbigny. {Itieria, Matheron, 1842), 
Coral-rag, Erance, belongs to the genus Nerincea (D'Orbigny), 
p. 244. 

CiTiTcrLLA., Gray. 

Type, C. ayellana, PL XIY., Pig. 4. 

Synonyms, Avellana and Einginella, D'Orbigny. 

Shell globular, thick, spirally grooved and punctate, spire 
small ; aperture narrow, rounded and sinuated in front ; outer 
lip thickened and reflected ; crenulated inside, columella with 
several tooth-like folds. 

Fossil, 21 species. Neocomian — Chalk. Britain, Prance. 

EiNGiCTJLA, V. p. 222, PL y.. Pig. 21. 
Globiconcha, D'Orbigny. 
Type, G-. rotundata, D'Orbigny. 
Fossil, 6 species. Chalk. Prance. 

Shell ventricose, smooth, aperture crescent-shaped, simple, 
not toothed or thickened on the columellar side. 

Yahigera, D'Orbigny. 1850.* 

Type, V. Guerangi, D'Orbigny. 

Fossil, 8 species. Neoc : — . Chalk. Prance. 

Shell like Glohiconcha, but with lateral varices. 

Tylostoma, Sharp. 1849. 

Type, T. Torrubise, Sharp. 

Etymology, Tulos, a callosity, stoma, mouth. 

Shell ventricose, smooth or punctate-striate, spire moderate, 
aperture ovate-lunate, pointed above, rounded in front ; outer 
lip periodically (once or twice in a whorl) thickened inside and 
expanded, rising slightly ; inner lip callous, spread over body- 
whorl. 

Distribution, 4 species. L. Cretaceous rocks, Portugal. 

* The dates of M. D'Orbigny's genera, given in the Prodrome de Paleontologies are 
dates of invention; the names were not published, in many instances, until ytdrs 
alterwards. 



GASTEROPODA. 315 

? Pteeodonta, D'Orbigny. 

Type, P. inflata, D'Orbigny. 

Fossil, 8 species. Clialk. France. 

Shell oblong, ventricose, spire elongated ; aperture oval, lip 
slightly expanded, notched in front, and with a tooth-like ridge 
internally, remote from the margin. 

? ToRNATiNA, A. Adams. 

Type, T. voluta. PL XIY., Fig. 5. 

Shell cylindrical or fusiform, spire conspicuous, apex sinistral, 
suture channeled, columella callous, 1 -plaited. 

Animal with a broad, trigonal head, rounded in front ; ten- 
tacular lobes triangular, with eyes at their outer bases ; foot 
short, truncated in front. 

Distribution, 24 species. West Indies, United States, Medi- 
terranean, Philippines, China, Australia. On sandy bottoms, 
ranging to 35 fathoms. (Adams.) 

Fossil, 13 species. Tertiary. 

Volvula, Adams (Bulla acuminata, Brug.), is a small con- 
voluted shell, with the spire concealed, and the columella 
obsoletely folded ; it is referred to Cylichna by Loven, to 
Ovulum by Forbes. Distribution, 12 species. Britain, Medi- 
terranean, Asia. Fossil, Pliocene — . Suffolk. 

Family II. — Bullid^. 

Shell globular or cylindrical, convoluted, thin, often punctate- 
striated ; spire small or concealed ; aperture long, rounded and 
sinuated in front ; lip sharp. No operculum. 

Animal more or less investing the shell; head a flattened 
disk,* with tentacular lobes, often united ; eyes immersed in the 
centre of the disk, or wanting ; foot oblong, furnished with a 
posterior lobe {meta-podium), and side-lobes [epipodia] ; gill 
single on the right side of the back, covered by the shell; 
mantle-margin simple or expanded, and enveloping the shell. 
Lingual dentition very various ; central teeth often wanting, 
laterals single or numerous. Gizzard armed with calcareous 
plates. Sexes united. 

* The cephalic expansion of the Bullidse is fonned by the fusion of the dorsal and 
oral tentacles. {Cuvier.) The tentacular lobes, or posterior part of the disk, is sup- 
plied with nerves from the olfadtory ganglia ; the anterior portion of the disk receives 
braiMihes from the labial nerve, which comes from the front margin of the cerebroid. 
{Hancock.) 

p2 



316 MAijnjAL or the mollusca. 

The BuUidce are animal feeders ; they are said to use their 
lateral lobes for swimmiiig. About 150 recent species have 
been described by Mr. A. Adams in Sowerby's Thesaurus Con- 
chyliorum. Fossil species date from the lower Oolites ; one is 
found in the Aralo-Caspian formation. 

BuiiLA, Lamarck. Bubble-shell, 

Type, B. ampulla, PL XIY., Fig. 6. 

Synonym, Haminea (hydatis), Leach. 

Shell oval, ventricose, convoluted, external or only partially 
invested by the animal ; apex perforated ; aperture longer than 
the shell, rounded at each end; lip sharp. 

Animal with a large cephalic disk, truncated in front, bilobed 
behind, the lobes laminated beneath; eyes sub-central, immersed 
or wanting ; lateral lobes very large, reflected on the sides of 
the shell, posterior lobe covering the spire ; foot quadrate ; 
gizzard famished with 3 chiton-like plates ; teeth. ? 

Bulla naucum {Atys, Montf. Alicula, Ehr. Roxania, Leach). 
PL XIY., Fig. 7 ; has the columella twisted, and the spire 
entirely concealed. 

Distrihution, 50 species. In all temperate and tropical seas, 
especially on sandy bottoms, ranging from low water to 25 or 30 
fathoms. 

Fossil, 70 species. Oolite — . South America, United States, 
Europe. 

Suh-genera? Crypt-opthalmus {sniaxsigdiimis), 'Eh.r. Eed Sea. 
Shell scarcely convolute, fragile, oval, convex, without spire or 
columella. Animal semi-cylindrical, head with short tentacular 
lobes, eyes small, concealed under the lateral margins of the 
head, mantle and lateral lobes enveloping the shell. 

Phaneropthalmus, A. Adams. (Xanthonella, Gray) B. lutea, 
Quoy, New Guinea. Shell oval, convex, pointed behind, 
columella margin with a curved process. Animal long, cylin- 
drical, head with short tentacular lobes, eyes in middle of disk, 
lateral lobes enveloping. 

Linteria, A. Adams (Glauconella, Gray ; Smaragdinella, A. 
Adams), Bulla viridis, Eang. PL XIY., Fig. 8. Shell oval, 
widely open, showing the rudimentary internal spire. Animal 
with a squarish, disk-like head, eyes sessile in the centre ; 
mantle not investing ; a posterior lobe ; lateral lobes envelop- 
ing. 

AcERA, Miiller. 

Type, A. buUata, PL XIY., Fig. 9. 
Etymology, Akeros, hornless. 



GASTEROPODA. 317 

Shell thin, flexible, globosely-cylindrical, spire truncated, 
whorls channeled ; aperture long, expanded and deeply sinuated 
in front, outer margin disunited at the suture ; colHimella open, 
exposing the whorls. 

Animal with a short and simple head-lobe, truncated in front 
and eyeless ; lateral lobes nearly concealing the shell ; lingual 
teeth hooked and serrulate, laterals about 40, narrow, claw- 
shaped ; gizzard armed with horny teeth. 

Distribution, 7 species. Grreenland, Britain, Mediterranean, 
Zanzibar, India, New Zealand. 

A. hullata is found amongst weed, in 1 — 15 fathoms water. 
(Eorbes.) 

CYLiCHisrA, Loven. 

Tyx)e, C. cylindracea, PI. XIY., Pig. 10. 

Synonym, BuUina, Eisso. 

Shell strong, cylindrical, smooth or punctate-striate ; spire 
m.inute or truncated ; aperture narrow, rounded in front ; 
columella callous, with one plait. 

Animal short and broad, not investing the shell; head 
flattened, truncated in front, with sub-centrally immersed eyes, 
tentacular lobes more or less united ; foot oblong, posterior and 
lateral lobes not much developed ; gizzard armed ; lingual teeth 
squarish, recurved and serrated, with 1 large and 5 or 6 small 
hooked laterals. 

Distribution, 40 species. United States, Greenland, Britain, 
Bed Sea, Australia. 

Fossil, Tertiary — . Britain. 

? Kleinella, a. Adams. 

Shell thin, dotted, striated, columella smooth, spire obtuse. 
Distribution, 1 species. Japan. 

Amphisphyra, Loyen. 

Type, A. pellucida, Johnst. {Amphi-sphyra, double hammer) 

Synonyms, Utriculus (part), Brown. Ehizorus, Montfort. 
Diaphana, Brown. 

Shell small, thin, ovate, truncated, spire minute papillary, 
aperture long. 

Animal entirely retractile into its shell ; head wide, short, 
with lateral triangular tentacles ; the eyes behind them minute, 
immersed ; muzzle bilobed in front ; foot oblong, truncated in 
front, notched behind ; teeth 1.1.1, central quadrate, serrulate ; 
laterals broad, hooked. 



818 MANUAL OF THE MOLLUSC! . 

Distribution, 7 species. United States, Norway, Britain, 
Borneo, Mexico. 

BuccEsruLUS, Blanchard. 

Shell tMck ; columella witli two plaits ; aperture small, entire 
in front. 

Distribution, 10 species. South Seas. 

Aplusteijm, Schumaclier. 

Type, Bulla aplustre, PI. XIY., Fig. 11. 

Etymology , aplustre, a ship's flag. 

Synonyms, Bullina, Fer. Hydatina (physis), Schum. Bullinula 
(scabra), Beck. 

Shell oval, ventricose, highly coloured ; spire wide, depressed ; 
aperture truncated in front ; outer lip sharp. 

Animal with a very large foot, extending beyond the shell all 
round, and capable of enveloping it ; a posterior lobe reflected 
on the spire ; mantle not investing ; tentacular lobes large, oval, 
ear-shaped ; labial tentacles four ; eyes small, black, sessile at 
the inner bases of the tentacles ; lingual teeth {B. physis) 
13.0.13, serrated. 

Distribution, 10 species. United States, West Indies, Mauri- 
tius, Ceylon, China, Australia. 

ScAPHAinDEE, Montfort. 

Type, S. lignarius, PI. XIY., Fig. 12. 

Etymology, scaphe, boat, aner, man. 

Shell oblong, convolute ; spirally striated ; aperture much 
expanded in front ; spire concealed ; epidermis thick ; lingual 
teeth 1.0.1, crested. 

Animal with a large oblong head, destitute of eyes; foot 
short and broad ; lateral lobes reflected, but not enveloping the 
shell ; gizzard with two large trigonal plates and a small narrow 
transverse plate (Fig. 17). It feeds on Dentalium entale. 

Distribution, 13 species. United States, Norway, Britain, 
Mediterranean on sandy ground ; 50 fathoms. 

Fossil, 8 species. Eocene — . Britain, France. 

PHiLniTE (Ascanius, 1762). 

Type, B. aperta, PI.' XIV., Fig. 13. 
Synonym. Bullsea. Lamarck. 

Shell internal, white, translucent, oval, slightly convoluted, 
spire rudimentary. 
Animal pale, slug-like ; mantle investing the shell ; kead 



GASTEEOPODA. 319 

olblong ; eyeless ; foot broad ; lateral lobes large, but not 
enveloping ; tongue with, two or four series of sickle-shaped 
nncini; gizzard with three longitudinal shelly plates. Egg 



Fig. 138. Philme aperta.* 

capsules ovate, in single series on a long spiral thread; fry 
with a ciliated head-veil and an operculated, spiral shell. 
(Loven.) 

JDistribution, 16 species. West Indies, Greenland, Norway, 
Britain, Mediterranean, Corea, Borneo. 

Fossil, 7 species. Eocene — . France. 

Siib-genus. Chelidonura, A. Adams, (Hirundella, Gray) B. 
birundinaria, Q,uoy, Mauritius. Shell concealed; outer lip 
produced posteriorly into a spur ; columellar border inflected. 
Animal with enveloping side-lobes ; mantle with two appendages 
behind, like the lateral processes of Hyalaea. 

DoRiDiUM, Meckel. 

Etymology, diminutive of Doris. 

Synonym, Acera, Cuvier. Eidothea, E-isso. 

Type, D. membranaceum, Meek. Mediterranean. 

Distribution, 3 species. South Europe. 

Animal oblong, truncated behind, the angles produced and 
dilated or filiform ; head ovate-oblong, retuse in front ; side- 
lobes expanded, wing-like; mantle investing a rudimentary, 
membranous shell. 

GASTEOPTEEOisr, Meckel. 

Type, G. Meckelii, Bl. (Clio amate, Chiaje) Mediterranean. 

Animal shell-less, oval, with side-lobes developed into wing- 
like expansions, meeting and uniting behind; cephalic disk 
triangular, obtuse in front, pointed behind, eyes centrally 
immersed; lingual teeth 5.1.5; mantle? branchial plume 
exposed on the right side ; reproductive orifice in front of the 

* From a specimen dredged at Folkestone ; o, mouth ; c, head, or cephalic disc, 
I, side-lobes of the foot; m, mantle. The sheU s, and gizzard^, are indistinctly seen 
through tlie translucent integuments. 



320 MANUAL OF THE MOLLIJSCA. 

gill, excretory opening behind it. Longitude 1, latitude 2 iiiclies. 
2 species. 

Physema, a. Adams. 

Shell glassy, globular, contracted in the middle and drawn 
out to a point in front. 

Distribution^ 1 species. "West coast of North America. 



Sormetus Adansonii, BL, is described as semi-cylindrical, with sides grooved, head 
indistinct ; shell unguiform, tliin, and transparent. 

Atlas {Peronii, El.), Lesueur. Head with two small tentacular lobes; body con- 
tracted in the middle ; foot dilated circularly, and fringed at the margin 

Pamilt in. — Apltsiad^. 

Bhell wanting, or rudimentary and coyered by the mantle, 
oblong, trigonal, or slightly convoluted. 

Animal slug-like, with distinct head, tentacles, and eyes; 
foot long, drawn out into a tail behind ; sides with extensive 
lobes, reflected over the back and shell ; branchial plume con- 
cealed. Sexes united. 

Aplysia, Gmelin. Sea Hare. 

Tijpe, A. depilans, PI. XIV., Fig. 14. 

Synonym, Siphonotus (geographicus) Ad. 

Bhell oblong, convex, flexible, and translucent, with a pos- 
terior slightly incurved apex. 

Animal oval, with a long neck and prominent back ; head 
with four tentacles, dorsal pair ear-like with eyes at anterior 
lateral bases ; mouth proboscidiform, with horny jaws, lingual 
teeth 13.1.13, hooked and serrated, about 30 rows; gizzard 
armed with horny spines ; sides with ample lobes folding over 
the back, and caj)able of being used for swimming ; gill in the 
middle of the back, covered by the shell and by a lobe of the 
mantle, which is folded posteriorly to form an excretory siphon. 

Distribution, 42 species. West Indies, Norway, Britain, 
Mediterranean, Mauritius, China. 

The Sea-hares are mixed feeders, living chiefly on sea-weed, 
but also devouring animal substances; they inhabit the 
laminarian zone, and oviposit amongst the weed in spring, at 
which time they are frequently gregarious. (Forbes.) They 
are perfectly harmless animals, and may be handled with 
impunity. When molested they discharge a violet fluid from 
the edge of the internal surface of the mantle, which does i.ot 
injure the skin, has but a faint smell, and changes to wine-red. 



GASTEROPODA. 321 

(Groodsiri) In old times tliey were objects of superstitious 
dread, on account of their grotesque forms, and the imaginary 
properties of their fluid, which was held to be poisonous and to 
produce indelible stains.* 

Fossil, one or two shells of the newest tertiary in Sicily have 
been doubtfully referred to this genus. 

Suh-^genus, Aclesia (dolabrifera). Bang, Shell trapeziform. 
Side -lobes closely enveloping the body, leaving only a small 
dorsal respiratory opening, surface ornament with filaments. 
9 species* East Indies. 

DoLAEEiiLA) Lamarck. 

Type, D. Eumphii, PL XIY., Pig. 15. 

Etymology, dolabella, a small hatchet. 

Shell hard, calcareous, trigonal, with a curved and callous 
apex. 

Animal like Aplysia, with gill near posterior extremity of the 
body and lateral crests closely appressed, leaving only a narrow 
opening ; ornamented with branching filaments. 

2)istrihution, 12 species. Mediterranean, Mauritius, Ceylon, 
Society Islands, Sandwich Islands. 

STYLOCHEILtJS, Gould, 1841. 

Synonym, Aplysia longicauda Q,. and G. 

Animal limaciform, cirrigerous, dilated at the sides, attenuated 
behind; neck distinct; tentacles 4, long, linear, papillose, far 
apart ; lips dilated laterally into tentacular processes. 

Distribution, 3 species. New Guinea, on Fuci. 

DoLABEiFEEA, Grube. 

Shell trapezoidal ; side-lobes not used for swimming. 
Distribution, 4 species, Indian Ocean, West America. 

SiPHON'OPYGE, Brown. 

Shell truncated in front ; foot-lobes spread out for swimming; 
posterior part extended beyond the siphon. 

Distribution, 6 species. West America, Chineise Sea. 

NoTABCHTJS, Cuvier. 

Type, ISr, Cuvieri, Bl. 

Etymology, nofos, the back, archos, vent. 

Synonym, Busiris (griseus), Eisso, ? Bursatella (Leachii), Bl. 

* Aplysia (from a and pluo) un-washable : the Aplasia of the G-reek fisherttien 
were sponges unfit for washing. 

p5 



322 MAJftriL OF THE MOLLrSCA. 

Animal shell-less, ornamented ■with filaments, sometimes 
dendritic, foot narrow, lateral crests united, leaving only a 
narrow branchial slit ; gills not covered by an opercular mantle 
lobe. 

Distribution, 7 species. Mediterranean, Eed Sea. 

ICABTJS, Forbes, 1843. 

Type^ I. Gravesii, F. 

Synonym, Lophocercus (Sieboldtii) Krohn, 1847. 

Shell like BuUeea ; convoluted, thin, ovate, covered with 
epidermis, outer lip separated at the suture, posterior angle 
inflected and rounded. 

Animal slender, papillose; tentacles 2, ear-shaped; eyes 
sessile on sides of head ; side-lobes reflected and partly covering 
the shell, united behind ; tail long and pointed. 

LoBiGER, Krohn. 

Type, L. Philippii, PL XIV., Fig. 16. Sicily. 

Shell oval, transparent, flexible, slightly convoluted ; covered 
with epidermis. 

Animal slender, papillose, with two flattened, oval tentacles, 
and minute sessile eyes on the sides of the head ; shell exposed 
on the middle of the back, covering the plume -like gill ; sides 
with two pairs of rounded, dilated lobes, or natatory appendages, 
foot linear, tail long and slender. 

Distribution, 4: si^eciea. Atlantic; South Europe. 

Family IV. — pLEtJROBKAircHrDJE. 

Shell limpet-like or concealed, rarely wanting ; mantle or 
shell covering the back of the animal ; gill lateral, between the 
mantle-margin and foot ; food vegetable, stomach extremely 
complicated. 

Pleurobranchits, Cuvier. 

Example, P. membranaceus, PL XIV. , Fig. 17. 

Etymology, pleura, side, branchia, gill. 

Synonyms, Berthella (plumula), BL Oscanius (membr.), G-rf y. 

Shell internal, large, oblong, flexible, slightly convex, 
lamellar, with a posterior, sub-spiral nucleus. 

Animal oblong, convex ; mantle covering the back and sides, 
papillated, containing spicula; foot large, separated from the 
mantle by a groove ; gill single, free at the end, placed on the 
right side between the mantle and foot ; orifices near the 



aASTEROPODA. 323 

base of tlie gill ,* head with two grooved tentacles, eyes at their 
outer bases ; mouth armed with horny jaws and covered by a 
broad veil with tentacular lobes. 

Distribution, 22 species. South America, Norway, Britain, 
Mediterranean, Eed Sea, Ceylon. 

Suh-genus ? Fleurohranchoea, Meckel ; P. Meckellii, Leve, 
Mediterranean. Synonym, Pleurobranchidium (maculatum), 
Quoy, South Australia. Mantle-margin very narrow, not 
concealing the gill ; dorsal tentacles ear-like, oral veil tentacu- 
liform. 

PosTEROBRANCHJBA, D'Orbigny. 

Type, P. maculata, D'Orbigny. Coast of Chili. 

Animal shell-less ; oval, depressed, covered by a mantle 
broader than the foot ; foot oblong, bilobed behind ; branchial 
plume on the left side, projecting posteriorly; reproductive 
orifice in front of gill, excretory behind ; proboscis covered by 
a broad bilobed veil ; no dorsal tentacles. 

EuNCESTA, (Forbes) Hancock. 

Type, E. Hancocki, Porbes. 

Synonym, PPelta, Quatr. (not Beck). 

Animal minute, slug-like, with a distinct mantle ; eyes 
sessile on the front part of the mantle; no tentacles; gills 3, 
slightly plumose, placed with the vent on the right side, at the 
hinder part of the back, beneath the mantle ; gizzard armed ; 
reproductive organs on the right side. 

Distribution on Qonferv(R near high-water mark, Torbay. 

Neda, H. and A. Adams. 

Animal shell-less ; mouth terminating a proboscis, which is 
long and thin; oral veil half-moon shaped, with two lateral 
recurved tentacles. 

Distribution^ 1 species. South Europe. 

StJSAEiA, Griibe. 

Sliell small ; mantle tuberculated, extending well over both 
head and foot ; notched in front. 

Distribution, 1 species. South Europe, 

Umbeella, Chemnitz. Chinese -umbrella shell. 

Type, U. umbellata, PL XIY., Pig. 18. 

Synonym, Acardo, Lam. Gastroplax, Bl. 

Shell, limpet-like, orbicular, depressed, marked by concontric 



324 MANTTAL OF TltE MOLLTTSCA. 

Iries of growth; apex sub-central, oblique, scarcely raised; 
margins acute ; inner surface with a central coloured and 
striated disk, surrounded by a continuous irregular muscular 
impression. It has a minute sinistral nucleus. 

Animal with a very large tuberculated foot, deeply notched 
in front ; mouth small, proboscidiform, retractile into the pedal 
notch, covered by a small-lobed yeil ; dorsal tentacles ear- 
shaped, with large plicated cavities at their bases ; eyes small, 
sessile between the tentacles ; mantle not extending beyond the 
shell ; gill forming a series of plumes beneath the shell in front 
and on the right side ; reproductive organ in front of the dorsal 
tentacles ; excretory orifice posterior, tubular. 

Distribution, 6 species. Canaries, Mediterranean, India, China, 
Sandwich Islands. 

Fossil, 4 species. Oolite — . United States, Sicily, Asia. 

Tylodina, Eafinesque. 

Type, T. punctulata, Eaf. (= citrina, Joannis). 3 species. 
Mediterranean, Norway. 

Fossil, 1 species. Tertiary. 

Shell limpet-like, depressed, apex sub-central, with a minute 
spiral nucleus. 

Animal oblong, foot truncated in front, rather pointed 
behind; dorsal tentacles ear-like, with eyes sessile at their 
inner bases ; oral tentacles broad ; branchial plume projecting 
posteriorly on the right side. 

Family Y. — Phtllidiad^. 

Animal shell-less, covered by a mantle, branchial laminae 
arranged in series on both sides of the body, between the foot 
and mantle. Sexes united. 

Phyllidia, Cuyier, 

Type, P. pustulosa, Cuvier. 

Etymology, diminutive of phyllon, a leaf. 

Animal oblong, covered with a coriaceous tuberculated 
mantle ; dorsal tentacles clavate, retractile into cavities near 
the front of the mantle ; mouth with two tentacles ; foot 
broadly oval ; gills forming a. series of laminae extending the 
entire length of both sides ; excretory orifice in the middle 
line, near the posterior end of the back, or between the mantle 
and foot; reproductive organs on the right side; stomach 
simple, membranous. 

Distribution, 5 species. Mediterranean, Eed Sea, India. 



GASTEROPODA. 826 

Feteria, Grube. 

Excretory orifice on tlie side of tlie foot ■ander tlie mantle, 
which is leathery and warty ; 6 gills entire length of both 
sides. 

Distribution^ 1 species. South Sea, East Africa. 

HYPOBEAisrcHi^A, A. Adams. 

Mantle cuticular ; gills limited to the hinder part of the 
body ; excretory orifices at the side, under the mantle. 
JDistributioTiy 1 species. Japan. 

DiPHYLLiDiA, Cuvier. 

Type^ D. Brugmansii, Cuvier. 

Bynonym, Pleurophyllidia, Chiaje. Linguella, Bl. 

Animal oblong, fleshy ; mantle ample ; gills limited to the 
hinder two-thirds of the body ; head with minute tentacles and 
a lobe-like veil ; vent at the right side, behind the reproductive 
orifices; lingual teeth 30.1.30. 

Bistrihution, 9 species. Norway, Britain {D. lineata, Otto), 
Mediterranean, India. 

SeCTIOIS' B.— NUDIBRAJSrCHIATA. 

Animal destitute of a shell except in the embryo state ; 
branchiae always external, on the back or sides of the body. 
Sexes united. 

The Nudibranchiate sea- slugs are found on all coasts where 
the bottom is firm or rocky, from between tide-marks to a 
depth of 50 fathoms ; a few species are pelagic, crawling on the 
stems and fronds of floating sea-weed. They have been found 
by Middendorff, in the Icy Sea, at Sitka, and in the sea of 
Ochotsk ; in the tropical and southern seas they are abundant. 
No satisfactory account, however, has been published of any 
except the European, and especially the British species, which 
form the subject of an admirable monograph by Messrs. Alder 
and Hancock, in the publications of the Eay Society. They 
require to be watched and drawn whilst living and active, since 
after immersion in spirits they lose both their form and colour. 
In some the back is covered with a doaJc or mantle (?), which con- 
tains calcareous spicula of various forms, sometimes so abun- 
dant as to form a hard shield-like crust. * The dorsal tentacles 
and gills pass through holes in the cloak somewhat like the 
*' key-hole" in Fissurella. In others there is no trace of a 

* According to Mr. Huxley, the *• cloak " of the Dorids is not the equivalent of the 
mantle, but " has more relation to the epipodium " 



8*26 MAKTTAL 01^ TfiE MOLItJSCA. 

mantle •whatevei'. The eyes appear as mimite black dot?, 
immersed in the skin, behind the tentacles; they are well 
organised a,nd conspicuous in the young, but often inyisible in 
the adult. The dorsal tentacles are laminated, like the antennae 
of many insects (Fig. 11, p. 17); they are never used as 
organs of touch, and are supplied with nerves from the olfactory 
ganglia. The nervous centres are often conspicuous by their 
bright orange colour; they are concentrated ahove the 
oesophagus ; three pairs are larger than the rest, the cerehroid 
in front, the branchial behind, and the j)edal ganglia at the 
sides. The cerebroid supplies nerves to the tentacles, mouth, 
and lips. 

The olfactory ganglia are sessile on the front of the cerebroid 
(in Boris), or situated at the base of the tentacles (in ^olis). 
The optic ganglia are placed on the posterior border of the 
cerebroid; the auditory capsules are sessile on the cerebroid, 
immediately behind the eyes, they contain an agglomeration of 
minute otolites^ which are continually oscillating.* The buccal 
ganglia are below the oesophagus, united to the cerebroid by 
commissures, forming a ring ; anterior to this a small ring is 
sometimes formed by the union of the fifth pair of nerves. The 
pedal ganglia (properly infra-oesophageal) are united laterally 
to the cerebroid and rarely meet below, but are united by com- 
missures which form (together with those of the branchial 
centres) the third ring, or great nervous collar. The branchial 
ganglia are united behind to- the cerebroid, and sometimes 
blend with them ; they supply the skin of the back, the rudi- 
mentary mantle, and the gills; beneath and sessile on their 
front border is the single visceral ganglion. Besides this excito- 
motory system (which includes the great centres, or brain, and 
the nerves of sensation and voluntary motion), the nudibranchs 
possess a sympathetic system, consisting of innumerable minute 
ganglia, dotted over all the viscera, united by nerves forming 
. plexuses, and connected in front with the buccal and branchial 
centres, t 

The digestive organs of the Nudibranchs present two remark- 
able modifications : in Doris and Tritonia the liver is compact 

* The atiditory capsules of other MoUusca (excepting the Nucleobranchs) axe 
attached to the posterior side of the pedal (sub-oesophageal) ganglia. 

t The sympathetic system supplies nerves to the heart and other organs which are 
independent of the will, and not ordinarily susceptible of pain ; they are called 
«' organic" nerves, as all the vegetative functions depend on them. Its existence in the 
Mollusoa was first clearly demonstrated by MM. Hancock and Embleton. The excito- 
motory system of the Mollusca corresponds with tlie cerebrospinal system of the 
vertebrata. 



GASTEROPODA. 



327 



and the stomach a simple membranous sac; whilst in j^olis 
the liver is disintegrated, and its canals so large that the 
process of digestion must be chiefly carried on in them, and 
they are regarded as coecal prolongations of the stomach ; the 
cceca extend into a series of gill-like processes, arranged upon 




Fig. 139. Dendronotus arborescens, 

the back of the animalj which also contain part or the whole of 
the true liver; the gastric ramifications vary exceedingly in 
amount of complexity. The Borididce are distinguished by 
having a short and wide lingual membrane with numerous 
similar teeth ; the Solids have a narrow ribbon with a single 
series of larger teeth. In Dendronotus a large central tooth is 
flanked by a few small denticulated teeth. (Alder and Hancock, 
H. II., Fig. 8.) 

The only Nudibranch with a solid upper jaw, is ^girua 
punctilucens (A. and H., PL XVII., Eig. 15). In other instances 
the two halves are articulated and act as lateral jaws. In 
^girue the mouth is also furnished with membranous fringes 
(A. and H., PI. XYIL, Pig. 14). Ancida cristata has a for- 
midable spinous collar (PL XYII.j Pig, 7). 




fig. 140. a, Mouth of ^girus punctilucenSo 

b. Horny upper mandible detached, 

c. Prehensile collar of Ancula. 

a, mantle ; x, dental sac ; h, insertion-plate of mandible ; c, passage of mouth. 

The vascular system and circulation of the nudibranchiate 
molluscs is incomplete. In Doris veins can be traced only in 
the liver and skin ; the greater part of the blood from the 
arteries escapes into the visceral sinus and into a network of 



328 MAKIJAL OP THE MOLttJSCA. 

sinuses in tlie skin^ from wMch. it returns to tlie auricle "by two 
lateral veins, without haying circulated through the gills. The 
heart is contained in a pericardium to "which is attached a small 
Ventriclej or portal heart, for impelling blood to the liver ; the 
hepatic veins run side by side with the arteries and open into a 
circular vein, surrounding the vent, and supplying the gills. 
Only hepatic blood, therefore, circulates through the gills. In 
^olis there are no special gills, but the gastro-hepa.tic papillae 
are accompanied by veins which transmit blood to the auricle. 
The skin acts as an accessory breathing-organ ; it performs the 
function entirely in the ElysiadcB, and in the other families, when 
by accident the branchise are destroyed. The water on the gills 
is renewed by ciliary action. The fry is provided with a trans- 
parent, nautiloid shell, closed by an operculum, and swims with 
a lobed head- veil fringed with cilia, like the young of most 
other gasteropods. (Hancock and Embleton, Phil. Trans. 1852. 
An. Nat. Hist. 1843.) 

Family YI.— Dorid^.* Sea-lemons. 

Animal oblong; gills plume-like, placed in a circle on the 
middle of the back ; tentacles two ; eye -specks immersed, 
behind the tentacles, not always visible in the adult ; lingual 
membrane usually with numerous lateral teeth, rachis often 
edentulous ; stomach simple ; liver compact ; skin strengthened 
with spicula, more or less definitely arranged. 

DoBis, L. 

Etymology-, doris, a sea-nymph. 

Example, D. Johnstoni, PL XIII. , Fig. 1. 

Synonyms, Dendrodoris, Eb. Hemidoris, Strp. 

Animal oval, depressed; mantle large, simple, covering the head 
and foot; dorsal tentacles 2, clavate or conical, lamellated, retrac- 
tile within cavities ; gills surrounding the Vent on the posterior 
part of the back, retractile into a cavity ; head with an oral 
veil, sometimes produced into labial tentacles ; mouth with a 
lower mandible, consisting of two horny plates, united near 
the front, and having 2 projecting points ; lingual teeth nume- 
rous, central small, laterals similar, hooked and sometimes 
serrated, 24-68 rows; 37-141 in a row; nidamental ribbon 
rather wide, forming a spiral coil of few volutions (p. 41, 
Pig. 29). 

* Contracted from Dorididce ; as the Greeks used Deucalides for Deucaliontiades. 
Ehrenberg divided the genus Doris into sections by the number and form of the giUs, 
characters of only specific importance. 



GASTEROPODA. 329 

Suh-gmus. Oncidoris (Bl ?). D. bilamellata, Jolinst. Back 
elevated, tuberculose ; gills non-retractile ; oral tentacles fused 
into a veil ; buccal mass with, a gizzard-like appendage ; lingual 
teeth 2 in each row. (A. and H.) 

D. scutigera {VilUersia), D'Orbigny, Eochelle ; has the mantle 
more than usually strengthened with calcareous spicula. 

Distribution, 100 species. 

The Dorids vary in length from 3 lines to more than 3 inches ; 
they feed on zoophytes and sponges, and are most plentiful on 
rocky coasts, near low water, but range as low as 25 fathoms. 
They occur in all seas, from Norway to the Pacific. 

HEPTABEAisrcHUS, A. Adams. 

Mantle without a longitudinal ridge on the back; 7 gills 
arranged in a semicircle ; oral tentacles star- shaped. 

Hexabranchtjs, Ehrenberg. 

Same as last, but with 6 gills arranged in a cross on the hinder 
part of the body ; oral tentacles notched. 

Atagema, Grube. 

Mantle with longitudinal ridge on the back ; tentacles clavate, 
retractile ; gills very small. 

Distribution, 1 species. New Zealand. 

ACTINOCYCLIJS, Ehrenberg. 

Animal ovate ; back naked ; gills very plumose. 
Distribution, 7 species. East Africa and South Europe. 

Cheomodoeis. 

Animal almost quadrangular; back naked; feathery gills 
arranged lineally. 

Distribution, 1 species. East India. 

AsTEEOisroTUS, Ehrenberg. 

Animal ovate : the apertures for the gills and tentacles almost 
closed. 

Distribution, 2 species. East Africa and South Europe. 

Glossodoeis, Ehrenberg. 

Synonym, Pterodoris, Eb. 

Tentacles retractile; back covered with unequal cylindrical 
processes ; a thread-like process on each side of the fore part of 
the foot. 

Distribution, 1 sppciQs. igast India and West America. 



530 MANUAL OP THE MOLLUSCA. 

GoNiODORis, Forbes. 

Etymology^ gonia, an angle. 

Type,. G. nodosa, PI. XIII., Pig. 2. 

Animal oblong ; tentacles clavate, laminated, non-retractile ; 
mantle small, simple, exposing the bead and foot. Spawn 
coiled irregularly. 

Distribution, 26 species. Norway, Britain (2 species), Medi- 
terranean, China. Between tide-marks. 

Teiopa, Johnston. 

Type, T. claviger, PI. XIII., Pig. 3. 

Synonym, Psiloceros, Menke. 

Animal oblong ; tentacles clavate, retractile within sheaths ; 
mantle margined with filaments ; gills few, pinnate, around or 
in front of the dorsal vent. (A. and H.) Lingual teeth 8.1.8, 
or 8.0.8. 

Distribution, 3 species. Norway and Britain. Low water — 
20 fathoms. 

-^GiiiTJS, Loven. 

T?/pe, JE. punctilucens, PI. XIII. , Pig. 4 

Etymology , ? aix {aigos), a goat. 

Animal oblong or elongated, covered with very large tubercles ; 
no distinct mantle ; tentacles linear, retractile within prominent 
lobed sheaths; gills dendritic, placed around the dorsal vent. 
(A. and H.) Lingual teeth 17.0.17. 

Distribution, 3 species. Norway, Britain (2 species), Prance. 
Littoral zone. 

Thecaceea, Pleming. 

Etymology, theke, a sheath, ceras, a horn. 

Type, T. pennigerum, Mont. 

Animal oblong, smooth ; tentacles clavate, laminated, re- 
tractile within sheaths ; head with a simple frontal .veil ; gills 
pinnate, placed round 'the dorsal vent, and surrounded by a row 
of tubercles. (A. andH.) 

Distribution, Britain, 2 species. Length, \ — J inch. Pound 
at low water. 

PoLYCERA, Cuvier. 

Etymology, polycera, many horns. 
Type, P. quadrilineata, PI. XIII. , Pig. 5. 
Animal oblong or elongated ; tentacles laminated, non- 
retractile, sheathless ; head-veil bordered with tubercles or 



GASTEKOPODA. 331 

tentacular processes ; gills with 2 or more lateral appendages. 
(A. and H.) 

Distribution, Norway (8 species), Britain, Eed Sea. Within 
tide-marks and in deep water on corallines. The spawn is strap- 
shaped, and coiled on stones, in July and August. P. ocellata 
{FlocamopJiorus, Eiippell) has the cephalic tentacles branched. 

Idalia, Leuckart. 

Etymology, Idalia, Venus, from Mount Idalium, in Cyprus. 

Synonyms, Euplocamus, Phil. Peplidium (Maderae), Lowe. 

Example, I. aspersa, PL XIII., Fig. 6. Coralline zone. 

Animal broadly oblong, nearly smooth, tentacles clavate or 
linear, with filaments at their base ; head slightly lobed at the 
sides ; mantle very small, margined with filaments ; lingual 
teeth 2.0.2. 

Bistrihution, 14 species. Norway, Britain (4 species), Medi- 
terranean, Madeira, Japan. 

Ajstcula, Loven. 

Synonym, Miranda, A. and H. 

Type, A. cristata. Alder. 

Animal slender, elongated; mantle entirely adnate, orna- 
mented with simple filaments ; tentacles clavate, .laminated ; 
with filiform appendages at their base ; labial veil produced on 
each side. 

Distribution, 2 species. Norway and Britain. Length, ^ inch. 

Ceeatosoma (Gray), A. Adams. 

Etymology, ceratois, horned, soma, body. 

Type, 0. cornigerum. Ad. 

Animal oblong, narrow, with two large and prominent horn- 
like processes on the posterior part of the back, behind the gills ; 
gills 5, bipinnate ; dorsal tentacles clavate, laminated, rising 
from rounded tubercles, non-retractile ; head with short lateral 
processes ; foot narrow. 

Distribution, 2 species. Sooloo Sea. (A. Adams.) 

Trevelyana, Kelaart. 1858. 

Body without a cloak. Two dorsal tentacles, without sheaths ; 
non-retractile. Mouth in front of head, without tentacles. 
Branchiee in a circular disk on the back, non-retractile. 

Distribution, 1 species (T, Oeylonica). Ceylon. 



332 MANUAL OF THE MOLLUSCA. 

Crimora, a. and H. 

Body limaciform. Cloak nearly obsolete, forming a veil with 
branched appendages over the head, and a papillated ridge on 
the sides of the back. Dorsal tentacles laminated, retractile 
within sheaths ; oral tentacles tubercular. Branchiae plumose, 
non-retractile. Lingual teeth 26.0.26. 

Pelagella, Grube. 

Animal oblong ; tentacles sheathless ; head -veil without pro- 
cesses ; ridge along the middle of the back, and two lateral ones; 
8 feathery gills arranged in a circle. 

Distribution^ 1 species. South Europe. 

Gymnodoeis, Steenstrup. 

Animal oblong ; tentacles sheathless ; gills, with lateral pro- 
cesses, dendritic, 2 or more in number. 
Distribution, 1 species. Japan. 

AcAi^THODoms, Grube. 

Animal oblong ; tentacles sheathless ; retractile within a 
cavity in the mantle ; several fleshy processes on the back ; 8 
feathery non-retractile gills. 

Distribution, 2 species. North Sea. 

Casella, H. and A. Adams. 

Tentacles retractile within sheaths ; gills laminated, with 6 
lobes. 

Distribution, 1 species. East India. 

Braghychlamis, Ehrenberg. 

Mantle long, angular ; tentacles in front of the edge of mantle. 
Distribution, 1 species. East Africa. 

Eamilt YII. — Tritoniad^. 

Animal with laminated, plumose, or papillose gills, arranged 
along the sides of the back ; tentacles retractile into sheaths ; 
lingual membrane with 1 central and numerous lateral teeth ; 
orifices on the right side. 

TRiTOiiiriA, Cuvier. 

Example, T. plebeia, PI. XIII., Pig. 7. 

Animal elongated ; tentacles with branched filaments ; veil 
tuberculated or digitated ; gills in single series on a ridge down 



GASTEROPODA. 333 

eacli side of tlie back ; mouth armed "witli liomy jaws ; stomach 
simple, liver compact. 

Distribution, 13 species. Norway and Britain. Under stones 
at low water, — 25 fathoms. T. Homhergii, Cuvier, found on 
the scallop-banks, attains a length exceeding 6 inches. 

SCTLL^A, L. 

Type, S. pelagica, PI. XIII., Pig, 8. 

Etymology, scyllaea, a sea-nymph. 

Animal elongated, compressed ; foot long, narrow, and chan- 
neled, adapted for clasping sea-weed; back with 2 pairs of 
wing-like lateral lobes, bearing small tufted branchiae on their 
inner surfaces ; tentacles dorsal, slender, with lamellated tips, 
retractile into long sheaths ; lingual teeth 24.1.24, denticulated ; 
gizzard armed with horny, knife-like plates ; orifices on the 
right side. 

Distribution, 7 species. Atlantic, South Britain, Mediter- 
ranean. On floating sea-weed. 

Nerea (punctata). Lesson, New Guinea ; 10 lines long, with 
ear-shaped tentacles, and 3 pairs of dorsal lobes. 

Tethys, L. 

Etymology, tethys, the sea (personified). 

Synonym, Fimbria, Bohadsch. 

Type, T. fimbriata, L., PI. XIIL, Pig. 9. 

Animal elliptical, depressed ; head corered by a broadly ex- 
panded, fringed disk, with 2 conical tentacles, retractile into 
foliaceous sheaths ; gills slightly branched, a single row down 
each side of the back ; reproductive orifices behind first gills, 
vent on right side, behind second gill ; stomach simple. 

Distribution, 1 species. Mediterranean. Attains a foot in 
length, and feeds on other molluscs and crustaceans. (Cuvier.) 

? BoRNELLA (Gray), A. Adams. 

Type, A. Adamsii, Gray. Length, 4 inches. 

Animal elongated ; dorsal tentacles retractile into branched 
sheaths ; head with stellate processes ; back with two rows of 
cylindrical, branched, gastric processes, to which small dendritic 
gills are attached;* foot very narrow. 

Distribution, 3 species. Straits of Sunda, on floating weed ; 
Borneo. 

• This observation deserves further inquiry. 



334 MANUAL OF THE MOLLTTSCA. 

? Dendronottts, a. and H.* 

Etymology y dendron, a tree, notos, the back. 

Type, D. arborescens, PI. XIII., Pig. 10. 

Animal elongated ; tentacles laminated ; front of the head 
with, branched appendages; gills arborescent, in single series 
down each side of the back ; foot narrow ; lingual teeth 10.1.10; 
stomach and liver ramified. 

Distribution, 3 species. Norway and Britain. On sea-weed 
and corallines ; low water — coralline zone. 

?DoTO, Oken. 

Etymology, doto, a sea-nymph. 

Example, D. coronata, PL XIII., Pig. 11. 

Animal slender, elongated ; tentacles linear, retractile into 
trumpet-shaped sheaths ; veil small, simple ; gills ovate, muri- 
cated, in single series down each side of the back ; lingual 
membrane slender, with above 100 recurved, denticulated teeth, 
in single series ; foot very narrow. 

The stomach is ramified, and the liver is entirely contained in 
the dorsal processes, which fall off readily when the animal is 
handled, and are soon renewed. 

Distribution, 4 species. Norway and Britain. On corallines 
in deep water — 50 fathoms. 

Gellina, Gray. 

Head simple ; papillae or gills smooth. 
Distribution, 1 species. North Sea. 

PMelibcea, Eang. 

Type, M. rosea. Rang ; on fioating weed, off the Cape. 

Animal elongated, with a narrow, channeled foot and long, 
slender tail ; sides of the back with 6 pairs of tuberculated lobes, 
easily deciduous ; tentacles cylindrical, retractile into long 
trumpet-shaped sheaths ; head covered by a lobe-like veil ; 
sexual orifices behind right tentacle, excretory behind first giJ. 
on the right side. 

Distribution, 3 species. South Sea and South Africa. 

? LoMAi;roTUS, Yerany. 

Example, L. marmoratus, PL XIII. , Pig. 12. 
Synonym, Eumenis, A. and H. 

* This and the following genera are placed by Alder and Hancock in the family 
^otidce; they have a ramified stomach, but their external {zoological) characte.'s 
agree better with Tritonia than ^olis. 



GASTEROPODA. 335 

Animal elongated, smooth ; liead covered witli a veil ; tentacles 
clavate, laminated, retractile into sheaths ; gills filamentose, 
arranged along the sides of the back, on the wavy margins of 
the mantle ; foot narrow, with tentacular processes in front ; 
stomach ramified. 

Distribution, 3 species. Britain and Mediterranean. On 
corallines. 

Family YIII. — ^olidjs. 

Animal with papillose gills (?), arranged along the sides of the 
back; tentacles sheathless, non-retractile ; lingual teeth 0.1.0; 
ramifications of the stomach and liver extending into the dorsal 
papillae ; excretory orifices on the right side ; skin smooth, with- 
out spicula ; no distinct mantle. 

^OLis, Cuvier. 

Synonyms, Psiloceros, Menke. Eubranchus, Forbes. Ampho- 
rina, Quatref. 
. Type, ^. papillosa, L. 
Etymology, yEolis, daughter of ^olus. 

Animal ovate ; dorsal tentacles smooth, oval, slender ; papillae 
simple, cylindrical, numerous, depressed, and imbricated ; mouth 
with a horny upper jaw, consisting of two lateral plates, united 
above by a ligament ; foot narrow ; tongue with a single series 
of curved, pectinated teeth ; spawn of numerous waved coils. 

Suh-genera. Flahellina, Cuvier. (Phyllodesmium, Ehr.) Body 
slender ; dorsal tentacles laminated, buccal long ; papillae 
clustered ; spawn multi-spiral. Example, E. Coronata, PL 
XIII., Fig. 13 (also Fig. 11, p. 17). 

Cavolina, Brug. (Montagua, Flem.), 0. peregrina. Body lan- 
ceolate ; tentacles smooth or wrinkled ; papillae in transverse, 
rather distant rows ; spawn of 1 or 2 coils. 

Facelina, Griibe. Like Flabellina, but with the foot small, 
and the two front angular portions drawn out to a point. 
Distribution, 5 species. Sitka, North Sea. 
Coryphella, Landsborough. Like Cavolina, but with papillsD 
arranged in groups. 4 species. 

Tergipes, Cuvier, T. lacinulata. Body linear ; tentacles 
smooth ; papillae in a single row on each side ; spawn kidney- 
shaped. 

Distrihution, Norway, Britain (33 species). United States, 
Mediterranean, South Atlantic, Pacific. Found amongst rocks at 
low water ; they are active animals, moving their tentacles con- 
tinually, and extending and contracting their papillsD ; they swim 



336 MANTAL OF THE MOLLTTSCA. 

readily at tlie surface, inverted. They feed chiefly on sertnlarian 
zoophytes, and if kept fasting will devour each other; when 
irritated they discharge a milky fluid from their papillae, which 
are very liable to fall off. 

Glatjctjs, Forster. 

Etymology, glaucus, a sea-deity. 

Synonyms, Laniogerus, Bl. Pleuropus, Eaf. 

Example, Or. Atlanticus, PI. XIIL, Fig. 14. 

Animal elongated, slender ; foot linear, channeled ; tentacles 
4, conical ; jaws horny ; teeth in single series, arched and 
pectinated; gills slender, cylindrical, supported on 3 pairs of 
lateral lobes; stomach giving off large coeca to the tail and 
side lobes ; liver contained in the papillae ; sexual orifice 
beneath first dextral papilla, vent behind second papilla; 
spawn in a close spiral coil. 

Distribution, 7 species. Atlantic, Pacific. Pound on floating 
sea- weed; devours small sea-jellies, Forjpitce and Velellce, 
(Bennet.) 

PiONA, Alder and Hancock. 

Type, P. nobilis, A. and H. 

Synonym, Oithona, A. and H. (not Baird). 

Animal elongated; oral and dorsal tentacles linear; mouth, 
armed with horny jaws ; gills (?) papillary, clothing irregularly 
a sub-pallial expansion on the sides of the back, each with a 
membranous fringe running down its inner side. 

Distribution, 3 species. Palmouth. Under stones at low 
water. (Dr. Cocks.) 

Embletonia, a. and H. 

Etymology, dedicated to Dr. Embleton, of Newcastle. 

Synonyms, Pterochilus, A. and H. ? Cloelia (formosa), Loven. 

Type, E. pulchra, PI. XIIL, Pig. 15. 

Animal slender; tentacles 2, simple; head produced into a 
flat lobe on each side; papillae simple, sub-cylindrical, in a 
single row down each side of the back. 

Distribution, 4 species. Scotland (2 species). In the littoral 
and laminarian zones. 

Calliopcea, (bellula), D'Orbigny. Brest ; has 2 rows of papiEsB 
down each side of the back; cephalic lobes subulate; vent 
dextral. Lon. 3 lines. 



GASTEEOPODA. 337 

Calma, Alder and Hancock. 

Animal sharply angular in front ; foot broad ; papillae simple 
and supported on cylindrical bases ; tentacles small. 
Distribution, 1 species. North. Sea. 

Eavoeinus, Griibe. 

Animal with slender cephalic tentacles knobbed at the 
extremity ; oral tentacles 2 pair ; papillae arranged in seYer< J 
oblique rows. 

Distribution, 1 species. North Sea. 

Galvesta, Alder and Hancock. 

Animal with papillae in transverse rows ; oral tentacles short 
and tapering ; rounded in front. 
Distribution, 2 species. North Sea. 

CuTHOisriA, Alder and Hancock. 

Animal with head naked and expanded ; papillae clavate and 
arranged in thick- set rows. 

Distribution, 1 species. North Sea. 

FiLTJETis, Dekker. 

Foot stunted ; body slender ; tentacles 2 ; mouth on a loose 
fringe of skin with 2 small oral feelers ; papillae in 2 long rows 
down the back. 1 species. 

Peoctonotus, a. and H. 

Type, P. mucroniferus, PI. XIII., Fig. 16. Dublin, shallow 
water. 

Synonyms, Yenilia. A. and H. Zephrina, Quatref. 

Animal oblong, depressed, pointed behind ; dorsal tentacles 
2, linear, simple, with eyes at their base, behind ; oral tentacles 
short ; head covered by a^ small semi-lunar veil ; mouth with 
horny jaws; papillae on ridges down the sides of the back and 
round the head in front ; vent dorsal. 

Distribution, 3 species. North Atlantic. 

AnsTTioPA, A. and H. 

Type, A. splendida, A. and H. 
Synonym, Janus, Yerany. 

Animal ovate-oblong, pointed behind ; dorsal tentacles lamel- 
lated, united at the base by an arched crest ; head with a small 

Q 



338 MANUAL OF THE MOLLITSCA. 

veil and two labial tentacles ; papillae ovate, placed along the 
lateral ridges of the back and continuous above the head ; vent 
central, posterior, sexual orifice at the right side ; lingual teeth 
numerous. ? 

Distribution, 3 species. Britain, Mediterranean. 

Herm^a, Loven. 

Type, H. bifida, PL XIII., Fig. 17. Norway, Britain. 

Animal elongated, tentacles folded longitudinally; papillae 
nnimerous, arranged down the sides of the back ; sexual orifice 
below right tentacles ; vent dorsal, or sub-lateral, anterior. 

Aldebia, AUman. 

Etymology, named after Joshua Alder, one of the authors of 
the " Monograph on the British Nudibranchiate Mollusca." 

Type, A. modesta, PL XIII., Pig. 18. 3 species. Norway, 
South Ireland, and South Wales. 

Animal oblong, without tentacles ; head lobed at the sides ; 
papillae arranged down the sides of the back ; vent dorsal, 
posterior. 

? Stiliger (ornatus), Ehrenberg ; Eed Sea. Yent dorsal, 
anterior. 

Chioejeea, Gould, 1855. 

Animal oblong ; head large, pedunculated and provided with 
oral cirri ; papillae foliaceous and arranged in two lateral rows ; 
generative organs on the right side. C. leonina, Puget Sound. 

PaMILY IX. — PHYLLIRHOrD^. 

Animal pelagic, foot-less (apodal), compressed, swimming 
freely with a fin-like tail ; tentacles 2, dorsal ; lingual teeth in 
a single series ; stomach furnished with elongated cceca ; orifices 
on the right side ; sexes united. 

Phylliehob, Peron and Lesueur. 

Etymology, phyllon, a leaf, rhoe, the wave. 

Synonym, Eurydice, Esch. 

Type, P. bucephala, Peron. 

Distribution, 6 species, Mediterranean, Moluccas, Pacific. 

Animal translucent, fusiform, with a lobed tail; muzzle 
round, truncated; jaws horny; lingual teeth 3.0.3; tentacles 
long and slender, with short sheaths ; intromittent organ long, 
bifid. 



GASTEROPOPA. o39 

Pamily X. — Elysiad^4 

Animal shell-less, litnaciform, with no distinct mantle or 
breathing- organ ; respiration performed by the ciliated surface 
of the body ; mouth armed with a single series of lingual teeth ; 
stomach central, vent median, sub -central; hepatic organs 
branched, extending the length of the body and opening into 
the sides of the stomach ; sexes united ; male and ovarian 
orifices below the right eye ; female orifice in the middle of the 
right side ; heart with an auricle behind, and traces of an arterial 
and venous system, eyes sessile on the sides of the head, 
tentacles simple or obsolete.* 

Elysia, Eisso. 

Typ^, E. viridis, PL XIIL, Eig. 19. 

Synonym, Actseon, Oken. 

Animal elliptical, depressed, with wing-like lateral expan- 
sions ; tentacles simple, with sessile eyes behind them ; foot 
narrow. 

iJistrihution, 8 species. Britain, Mediterranean^ On Zostera 
and sea-weed, in the laminarian zone. Flaco-hranckus (ocellatus, 
Eang.) Hasselt, Java; described aS' 2 inches long, with four 
small tentacles ; the lateral expansions much developed and 
meeting behind, the upper surface longitudinally plaited, and 
forming, when the side-lobes are rolled together, a sort of 
branchial chamber. 

AcTEONiA, Quatrefages* 

Example, A. corrugata, PI. XIII., Eig. 20. British Channel. 

Animal minute, leech-like ; head obtuse, with lateral crests 
proceeding from two short conical tetitacles, behind which are 
the eyes. 2 species. 

Cenia, Alder and Hancock. 

Type, C. Cocksii, PI. XIIL, Eig. 21. 
Etymology, cenia, Ealmouth. 
Synonym ? Eucola (rubra) (Quoy). 

* Order JDermi-branckiata, Quatref. {Pelli-bTanchiata, A. and ll.) M. Quatre- 
fages erroneously described the Elysiadce as wanting both heart and blood-vessels, like 
the Ascidian zoophytes ; witli them he associated the family jEolid(E, which he described 
as having a heart and arteries, but no veins, their ofBce being perfoniied by lacunee of 
the areolar tissue. In both families the product of digestion (chyle) was supposed to 
be aerated in the gastric ramifications, by the direct influence of the surrounding 
water. To this group, which has been since abandoned, he applied the name Phleben- 
terata {phlebs, a vein, entera, the intestines). 

Q 2 



340 MANUAL OF THE MOLLUSCA. 

Animal limaciform, back elevated, head slightly angnlated, 
bearing two linear dorsal tentacles, with, eyes at their outer 
bases behind. 

LiMAPONTiA, Johnston. 

Type, L. nigra, PL XIII., Pig. 22. 

Synonyms^ Chalidis, Q,u. Pontolimax, Cr. 

Animal minnte, leech-like ; head truncated in front, with 
arched lateral ridges on which are the eyes ; foot linear. 

Distribution, Norway, England, and France, between half- 
tide and high- water, feeding on Conferv(e, in the spring and 
summer ; spawn in small pear-shaped masses, each with 50- 
150 eggs ; fry with a transparent nautiloid shell, closed by an 
operculum. 

Ehodope, KoUiker, 1847. 

Example, E. Veranii. 

Animal minute, similar to Limapontia ? worm-shaped, rather 
convex above, flat beneath ; without mantle, gills, or tentacles. 
Upon algse, Messina. 

OEDEE ly.— NUCLEOBEANCHIATA. Bl.* 

The present order consists entirely of pelagic animals, which 
swim at the surface, instead of creeping on the bed of the sea. 
Their rank and affinities entitle them to the first place in the 
class ; but their extremely aberrant form, and unusual mode of 
progression, have caused us to postpone their description till 
after that of the ordinary and typical gasteropoda. 

There are two families of nucleobranchiate molluscs ; the 
firolas and carinarias, with large bodies and small or no shells, 
and the Atlantas, which can retire into their shells and close 
them with an operculum. Both animal and shell are sym- 
metrical, or nearly so " the nucleus of the shell is minute and 
dextrally spiral. 

The nudeohrancJis swim rapidly by the vigorous movements 
of their fin-like tails, or by a fan-shajDed ventral fin ; and 
adhere to sea-weed by a small sucker placed on the margin of 
the latter. Mr. Huxley has shown that these organs repre- 
sent the three essential parts of the foot in the most highly- 
developed sea-snails. The sucker represents the central part of 
the foot, or creeping disk {meso-podium) of the snail and whelk; 
the ventral fin is homologous with the anterior division of the 

* So called because the respiratory and digestive organs form a sort of nucleus on 
ILe posterior part of the back. See Fig. 141, s, b, and PL XIV., Fig. 24. 



&ASTEEOPODA. g-jtl 

foot (pro-podium), "which is very distinct in Natica (p. 235), and 
in Harpa and Oliva ; but is only marked by a groove in. 
Paludina and DoUum (Fig. 87). The terminal fin (or tail of 
Carinaria), which carries the operculum of Atlanta, is the 
equivalent of the operculigerous lobe [meta-podium) of the ordi- 
nary gasteropods, such as Sfromhus (Fig. 76). 

The abdomen, or visceral mass, is small, whilst the anterior 
part of the body (or cephalo-thorax, M. Edwards) is enormously 
developed. The proboscis is large and cylindrical, and the 
tongue armed with recurved spines. The alimentary canal of 
Firola is bent up at a right angle posteriorly on the dorsal side ; 
in Atlanta it is recurved, and ends in the branchial chamber. 
The heart is proso-hranchiate, although in Firola the auricle is 
rather above than in front of the ventricle, owing to the small 
amount of the dorsal flexure. 

The nucleobranchs, and especially those without shells, 
* ' afford the most complete ocular demonstration of the truth 
of Milne Edwards's views with regard to the nature of the cir- 
culation in the mollusca. Their transparency allows the blood- 
corpuscles to be seen floating in the general cavity of the body 
— between the viscera and the outer integument — and drifting 
backwards to the heart ; having reached the wall of the auricle 
they make their way through its meshes as they best can, 
sometimes getting entangled therein, if the force of the heart 
has become feeble. Erom the auricle they may be followed 
to the ventricle, and thence to the aorta and pedal artery, 
through whose open ends they pour into the tissues of the head 
and fin." (Iluxley.) 

Such delicate and transparent creatures would hardly seem to 
need any special breathing-organ, and, in fact, it is present or 
absent in species of the same genus, and even in specimens of 
the same species. Carinaria has fully-formed branchise ; in 
Atlanta they are sometimes distinct, and wanting in others ; in 
Firoloides they are only indicated by a ciliated sub-spiral band. 
The larvse are furnished with a shell, and with ciliated vela. 
(Gegenbaur.) 

The nucleobranchs are dicecious ; some individuals (of Firola) 
have a leaf-like appendage, others a long slender egg-tube 
depending from the oviduct, and regularly annulated.* The 
larvae are furnished with a shell and with ciliated vela. (Gegen- 
baur.) 

The nervous system is remarkable for the wide separation of 

* We can only call to mind one otlier example of a segmented organ in the mcUusca, 
viz., the penniform styles of Teredo bi]:almulata. 



342 MANUAL OF THE MOLLUSCA. 

the centres. The buccal ganglia are situated considerably in 
front of the cephalic, and the pedal ganglia are far behind, so 
that the commissures which unite them are nearly parallel with 
the oesophagus. The branchial ganglia are at the posterior 
extremity of the body, as in the bivalves. The eyes are hour- 
glass shaped, and very perfectly organised ; the auditory 
vesicles are placed behind, and connected with the cephalic 
ganglia, they each contain a round otolite, which sometimes 
seems to oscillate. (Huxley.) 

Family I. — ^FmoLiDiE. 

Animal elongated, cylindrical, translucent, furnished with a 
ventral fin, and a tail-fin used in swimming ; gill exposed on 
the posterior part of the back, or covered by a small hyaline 
shell. Mouth with a circular lip ; lingual membrane with few 
rows of teeth ; central teeth transversely elongated, with 3 
recurved cusps ; laterals 3 on each side, the first a transverse 
plate with a hooked apex, 2 and 3 sickle-shaped. * 

FiEOLA, Peron and Lesueur. 

Type, F. Coronata, Forsk. Mediterranean. 

Synonym, Pterotrachsea, Forsk. 

Anin}al fusilbrm, elongated, with a long, slender, proboscidi- 
form head; fin narrowed at the base, furnished with a small 
sucker ; tail elongated, keeled, sometimes pinnate ; nucleus 
prominent; branchial processes numerous, conical, slender; 
tentacles 4, short and conical ; eyes black and distinct, protected 
by a rudimentary eyelid ; lingual ribbon oblong. The female 
firolce have a long moniliform oviduct. Anpps Feronii, 
D'Orbigny, described and figured as having no head (!), was 
probably a mutilated Firola. " Such specimens are very 
common, and seem just as lively as the rest." (Huxley.) 

Distribution, 14 species. Atlantic, Mediterranean, Pacific. 

Sub-genus. Firoloides, JjQSuenr. (CerqpAora, D'Orbigny). F. 
Desmarestii, Les. Body cylindrical ; head tapering, furnished 
with two slender tentacles ; nucleus at the posterior extremity 
of the body, with or without small branchial filaments ; egg- 
tube regularly annulated ; tail-fin small and slender, ventral 
fin without a sucker. Distribution, 6 species. Atlantic ; Medi- 
terranean. 

* The genus Sagitfa, Q. and ,G., scmetimes referred to this family, is aa jvrticrlate 
auiiaaL (Huxley.) 



GASTEEOPOBA- 

Caeinaeia, Lamarck. 



143 




Fir 141.* 

Etymology^ carina, a keel (or keeled vessel). 

Type, C. cymbiuni, Desh. == 0. cristatus, L., Eig. 141, PI. 
XIV., Eig. 19. 

Shell hyaline, symmetrical, limpet- shaped, with a posterior 
sub-spiral apex and a fimbriated dorsal keel • nucleus minute, 
dextrally spiral. 

Animal large, translucent, granulated; head thick, cylin- 
drical; lingual ribbon triangular, teeth increasing rapidly in 
size, from the front backwards ; tentacles long and slender, eyes 
near their base ; ventral fin rounded, broadly attached, with a 
small marginal sucker ; tail large, laterally compreseed ; nucleus 
pedunculated, covered by the shell, gills numerous, pinnate, 
projecting from beneath the shell. 

Distribution, 8 species. Mediterranean and warmer parts of 
the Atlantic and Indian Oceans. They feed on small Acakphce, 
and probably on the jpteropoda ; Mr. Wilton found in the 
stomach of a Carinaria two fragments of quartz rock, weighing 
together nearly 3 grains. 

Fossil, 1 species. Miocene. Turin. 

Oaediapoda, D'Orbigny. 

Example, C. placenta, PI. XIY., Pig. 20. 
Etymology, cardia, heart, potis, foot. 
Synonym, Carinaroides, Eyd. and Souleyet. 
Animal like Carinaria. 
Distrihution, 5 species. Atlantic. 

Shell minute, cartilaginous ; peristome expanded and bi-lobed 
in front, enveloping the spire behind. 

Eamilt II. — ^Atlantidje. 
Animal famished with a well-developed shell, into which it 
* Fig. 141. p, proboscis ; t, tentacles ; b, branchia ; s, shell ; /, foot ; d, disc. 



344 MANUAL OF THE MOLLUSC A. 

can retire ; gills contained in a dorsal mantle cavity ; Hngual 
tocth similar to Carinaria. 

Shell symmetrical, discoidal, sometimes closed by an oper- 
culum. 

Atlanta, Lesueur. 

Tijjje, A. Peronii, PI. XIV., Figs. 21-23. 

Si/nonym, steira, Esch.. 

Shell minute, glassy, compressed and prominently keeled; 
nucleus dextrally spiral ; aperture narrow, deeply notclied at 
the keel; operculum, ovate, pointed, lamellar, with a minute, 
apical, dextrally spiral nucleus. 

Animal 3-lobed ; head large, sub -cylindrical ; tentacles 
conical, with conspicuous eyes behind them ; ventral fin 
flattened, fan- shaped, furnished with a small fringed sucker; 
tail pointed, operculigcrous. 

Distribution, 18 species. Warmer parts of the Atlantic, 
Canary Islands. 

Sub-genus. Oxygyrus, Benson. Synonyms, Ladas, Cantraine ; 
Helico-phlegma, D'Orbigny. O. Keraudrenii, PI. XIII., Figs. 
24, 25. Shell milky, narrowly umbihcated on both sides ; 
nucleus not visible ; back rounded, keeled only near the aper- 
ture ; body whorl, near the aperture, and keel cartilaginous ; 
no apertural slit ; operculum trigonal, lamellar. 4 species. 
Atlantic, Mediterranean. 

The Atlanta was discovered by Lamanoii, who supposed it to 
be the living analogue of the Ammonite. The operculum of 
Oxygyrus (PL XIII., Fig. 25) is singularly like the TrigonelUtes 
(p. 182) ; that of Atlanta (Fig. 22) is the only example of a 
dextral operculum to a dextral shell (p. 207). 

POECELLIA, Leveille. 

Example, P. Puzosi, PI. XIY., Fig. 29. 

Shell discoidal, many-whorled ; whorls keeled or coronated ; 
nucleus spiral ; aperture with a narrow dorsal slit. 

Fossil, 10 species. Upper Silurian — Trias. Britain, Bel- 
gium. 

BELLEEOPHOisr, Montfort. 

Example, B. bi-carinatus. Lev. PI. XIY., Fig. 27. 

Synonym, Euphemus, M'Coy. 

67/e/^^ symmetrically convoluted, globular, or discoidal, strong, 
few-whorled ; whorls often sculptured ; dorsally keeled ; aper- 
tu.re sinuated and deeply notched on the dorsal side. 



GASTEROPODA. 345 

Fossil, 128 species. Lower Silurian — Carb. North America, 
Europe, Australia, India. The name Bucania was given by 
Hall to the species with exposed whorls ; in B. expansus, PI. 
Xiy., Fig. 28, the aperture of the adult shell is much expanded, 
and the dorsal slit filled up. (Salter.) 

Bellerophina, D'Orbigny (not Forbes), is founded on the 
Nautilus minutus. Sby. PI. XIV., Pig. 26, a small globular 
shell, spirally striated, and deyoid of se^pta. It is found in the 
gault of England and Prance. 

Cyetolites, Conrad. 

Type, C. ornatus, PI. XIY., Pig. 30. 

Etymology , kurtos, curved, lithos, stone. 

Shell thin, symmetrical, horn-shaped or discoidal, with whorls 
more or less separate, keeled, and sculptured. 

Fossil, 13 species. Lower Silurian — Carb. North America, 
Europe. 

? Ecculiomphalus (Bucklandi), Portlock, PI. XIY., Pig. 31. 
Lower Silurian, Britain, United States. Shell thin, curved, or 
discoidal with few widely separate whorls, slightly unsym- 
metrical, keeled. 





Fig. 142. Maclurea Logani (Salter), L. Silurian, Canada. 

PMacltjeea, Lesueur. 

Named after William Maclure, the first American geologist. 

Shell discoidal, few-whorled, longitudinally grooved at the 
back, and slightly rugose with lines of growth; dextral side 
convex, deeply and narrowly perforated ; left side flat, exposing 
the inner whorls ; operculum sinistrally sub-spiral, solid with 
two internal projections {t t), one of them beneath the nucleus, 
very thick and rugose. 

Fossil, species. Lower Silurian. North America ; Scotlani 
(Ayrshire, M'Coy). 

This singular shell abounds in the " Cha2y " limestone of 
the United States and Canada; sections of it may be seea 
even in the pavement of New York ; but specimens are vei y 
difiicult to obtain. We are indebted to Sir W. E. Logan, 
of the Geological Survey, Canada, for the opportunity of 

q3 



846 MAisruAj:, op the mollttsca. 

examining a large series of silicified specimens, and of figuring 
a perfect sltell, vrith. its operculum in situ. It has more tlie 
aspect of a bivalve, such as Requienia Lonsdalii (PL XVIII., 
Pig. 12) than of a spiral univalve, but has no hinge. Many of 
the specimens are overgrown with a zoophyte, generally on the 
convex side only, rarely on both sides. 

The Maclurea has been described as sinistral ; but its oper- 
culum is that of a dextral shell ; so that the spire must be 
regarded as deeply sunk and the umbilicus expanded, as in 
certain species of planorhis ; unless it is a case conversely 
parallel to Atlanta, in which both shell and operculum have 
dextral nuclei. The affinities of Maclurea can only be deter- 
mined by careful examination and comparison with allied, but 
less abnormal fprras, associated with it in the oldest fossiliferous 
rocks ; its relation to Euomphalus (p. 267) is not supported by 
the evidence of Sir W. Logan's specimens. 



GLASS III.— PTEEOPODA. 

This little group consists of animals whose entire life is 
passed in the open sea, far away from any shelter, save what is 
afforded by the floating gulf- weed, and whose organisation is 
specially adapted to that sphere of existence. In appearance 
and habits they strikingly resemble the fry of the ordinary sea- 
snails, swimming like them by the vigorous flapping of a pair 
of fins. To the naturalist ashore they are almost unknown ; 
but the voyager on the great ocean meets with them where 
there is little else to arrest his attention, and marvels at their 
delicate forms and almost incredible numbers. They swarm 
in the tropics, and no less in Arctic seas, where by their 
myriads the water is discoloured for leagues. (Scoresby.) They 
are seen swimming at the surface in the heat of the day, as well 
as in the cool of the evening. Some of the larger kinds have 
prehensile tentacles, and their mouths armed with lingual teeth, 
so that, fragile as they are, they probably feed upon f^till 
smaller and feebler creatures (e.g. entomostraca). In liigh 
latitudes they are the principal food of the whale, and of many 
sea-birds. Their shells are rarely drifted on shore, but abound 
in the fine sediment brought up by the dredge from great 
depths. A few species occur in the tertiary strata of England 
and the Continent ; in the older rocks they are unknown, unless 
some comparatively gigantic forms [conularia and theca) have 
been rightly referred to this order. 



PTEROPODA. ^47 

In structtir©j tlie Pteropoda are most nearly related to tlie 
marine univalves, but much inferior to them. Their nervous 
ganglia are concentrated into a mass helow the oesophagus ; they 
have auditory vesicles, containing otolites ; and are sensible of 
light and heat, and probably of odours, although at most they 
possess very imperfect eyes and tentacles. The true foot is 
small or obsolete ; in deodora it is combined with the fins, but 
in Clio it is sufficiently distinct, and consists of two elements ; 
in Spirialis the posterior portion of the foot supports an oper- 
culum. The fins are developed from the sides of the mouth or 
neck, and are the equivalents of the side-lappets {epipodia) of 
the sea-snails. The mouth of Pneumodermon is furnished with 
two tentacles supporting miniature suckers ; these organs have 
been compared with the dorsal arms of the cuttle-fishes, but it 
is doubtful whether their nature is the same.* A more certain 
point of resemblance is the ventral flexure of the alimentary 
canal, which terminates on the under surface, near the right 
side of the neck. The pteropods have a muscular gizzard, armed 
with gastric teeth ; a liver ; a pyloric coeoum ; and a contractile 
renal organ opening into the cavity of the mantle. The heart 
consists of an auricle and a ventricle, and is essentially opistJio- 
hranchiate, although sometimes afieoted by the general flexure 
of the body. The venous system is extremely incomplete. The 
respiratory organ, which is little more than a ciliated surface, is 
either situated at the extremity of the body and unprotected by 
a mantle, or included in a branchial chamber with an opening 
in front. The shell, when present, is symmetrical, glassy, and 
translucent, consisting of a dorsal and a ventral plate united, 
with an anterior opening for the head, lateral slits for long fili- 
form processes of the mantle, and terminated behind in one or 
three points ; in other cases it is conical, or spirally coiled or 
closed by a spiral operculum. The sexes are united, and the 
orifices situated on the right side of the neck. According to 
Yogt, the embryo Pteropod has deciduous vela, like the sea- 
snails, before the proper locomotive organs are developed. 
(Huxley.) 

Erom this it would appear that while the Pteropoda present 
some analogical resemblances to the Cephalopoda, and perma- 
nently represent the larval stage of the sea-snails, they are 
developed on a type sufficiently peculiar to entitle them to rank 

* The figures of Ej'donx and Souleyet represent them as being supplied with nerves 
from the cephalic ganglia ; whereas the arms of the cuttle-fish, and all other parts or 
modifications of the foot in the mollusca, derive their nerves from the pedal ganglia. 
(Huxley.) 



348 MANFAl OF THE MOLITJSCA. 

as a distinct group ; not indeed of equal value with tlie OasterO" 
foda, but with, one of its orders. 

This group, the lowest of the univalve or encephalous orders, 
makes no approach, towards the bivalves or acephala. Forskahl 
and Lamarck indeed compared Hyalcea with Terehratula ; but 
they made the ventral plate of one answer to the dorsal valve of 
the other, and the anterior cephalic orifice of the pteropodous 
shell correspond with the 'posterior^ byssal foramen of the 
bivalve ! 

Sectioit a. — Thecosomata, B1.* 

Animal furnished with an external shell ; head indistinct ; 
foot and tentacles rudimentary, combined with the fins ; mouth 
situated in a cavity formed by the union of the locomotive 
organs ; respiratory organ contained within a mantle cavity. 

Family I. — Hyaleid^. 

Shell straight or curved, globular or needle-shaped, sym- 
metrical. 

Animal with two large fins, attached by a columellar muscle 
passing from the apex of the shell to the base of the fins ; body 
enclosed in a mantle ; gill represented by a transversely plaited 
and ciliated surface, within the mantle cavity, on the ventral 
side; lingual teeth (of ZT^/a/m) 1.1.1, each with a strong recurved 
hook. 

Hyalea, Lamarck 

Etymology, hyaleos, glassy. 
Synonym, Cavolina, Gioeni, not Brug. 
TijjJe, H. tridentata. Fig. 143. PI. XIY., Fig. 32. 
Shell globular, translucent ; dorsal plate lather flat, produced 
into a hood ; aperture contracted, with a slit on each side ; 

posterior extremity tridentate. In 

/S ^^ -^^^^Z"^^""^ ^^ H. trispinosa [Diacria, Grray) the 

^<iA ^. -Jy lateral slits open into the cervical 

[ aperture. 

I L Animal with long appendages to the 

///*"^^^\\ mantle, passing through the lateral 

// W \\ slits of the shell ; tentacles indistinct ; 

/ v fins united by a semicircular ventral 

' F lobe, the equivalent of the posterior 

Fig. 143. H. tridentata. element of the foot. 

Distribution, 19 species. Atlantic, Mediterranean, Indian 
<^cean. 
Fossil, 6 species. Miocene — . Sicily, Turin, Dax. 

* Theke, a case, soma, a body ; several of the geuera have no eliells. 



PTEEOPODA. 349 

Cleodora, Peron and Lesuetir. 

Synonyms, Clio, L. (part) not Miiller. Balantium, Leach MS. 

Type, 0. pyramidata, PI. XIY., Fig. 33. 

Shell pyramidal, tkree-sided, striated transversely ; ventral 
side flat, dorsal keeled ; aperture simple, triangular, with, the 
angles produced ; apex acute. 

Animal with rudimentary eyes ; tentacles obsolete ; mantle- 
margin with a siphonal (?) process ; fins ample, united ventrally 
by a rounded lobe ; lingual teeth 1.1.1. The transverse bars of 
the gills, the heart, and other organs are visible through the 
pellucid shell. In G. curvata and pellucida {Pleuropiis, Esch.) 
the mantle is furnished with two long filaments on each side. 

Distribution, 12 species. Atlantic, Mediterranean, Indian 
Ocean, Pacific, Cape Horn. 

Fossil, 4 species, Miocene — . Britain. [C. infundibulum, 
Crag.) 

Suh' genus. Oese^s, Eang. (Styliola, Lesueur.) C. aciculata, 
PI. XIY., Fig. 34. Slender, conical, pointed, straight, or curved. 
Fins rather narrow, truncate, with small tentacles projecting 
from their dorsal edges, and rudiments of the mesopodium on , 
their surface ; mantle-margin with a spiral process on the left 
side. M. Eang states that he has seen these pteropods clustering 
round floating seaweed. 

Distribution, 6 species (like Gleodora). 

CuviEMA, Eang.* 

Dedicated to Baron Cuvier. 

Type, C. columnella, Eang, PI. XIY., Fig. 35. 

Shell cylindrical, transparent ; aperture simple, transversely 
ovate ; apex acute in the young, afterwards partitioned ofi", and 
usually deciduous. 

Animal with simple narrow fins, united ventrally by two small 
lobes; lingual teeth 1.1.1. 

Distribution, 4 species. Atlantic, India, Australia. 

Fossil, 1 species. (C. astesana, Eang.) Pliocene, Turin. 

Sub-genus. Vaginella, Daud. Y. depressa, PI. XIY., Fig. 36, 
She'll oblong, with a pointed apex ; aperture contracted, trans- 
verso. Fossil, 4 species. Miocene. Bordeaux, Turin. 

Theca, Morris. 1845. 
Type, T. lanceolata. 

* Under the name of "triptere," MM. Quoy and Gaimard described the fragment 
of a ptcrop d, since ascertained to have been a Cuvier m. 



350 MANTTAL OF THE MOLLTTSCA. 

Synonyms, Creseis, Porbes.* Pugiunculus, Barr. 

Shell straight, conical, tapering to a point, back flattened, 
aperture trigonal. Length, 1-8 inches. 

Fossil, 40 species. Palaeozoic, North America, Britain, New 
South Wales, ? Permian, 

Pteeotheca, Salter, 

TypCy P, transversa, Portlock. 3 species, Lower Silurian ; 
Ireland, Wales, Canada, 

Shell bi-lobed, transversely oval, with a dorsal keel projecting 
slightly at each end ; ventral plate small triangular, 

? CoNTJLAHiA, Miller. 

Etymology, conulus, a little cone. 

Type, C. quadrisulcata, Pig. 144. 

Shell four-sided, straight, and tapering, the angles 
grooved, sides striated transv-ersely, apex partitioned 
ofle. 

Fossil, 40 species. Silurian — Garb. North America, 
Europe, Australia. 

Sub-genus. Coleoprion (gracilis), Sandberger ; 
Devonian. Germany. Shell round, tapering, sides 
obliquely striated, striae alternating along the dorsal 
line. 
^ig' i*4-t EunYBiA, Eang, 1827.| 

Etymology, Euryhia, a sea-nymph. 

Synonym, Theceurybia, Bronn. 

Example, E. Gaudichaudi, PL XPV., Pig. 37 (after Huxley). 

Animal globular ; fins narrow, truncated, and notched at the 
ends, tinited ventrally by a small lobe (metapodium) ; mouth 
with two elongated tentacles, behind which are minute eye- 
peduncles and a two-lobed rudimentary foot [mesopodium) ; body 
enclosed in a cartilaginous integument, with a cleft in front, 
into which the locomotive organs can be retracted. Lingual 
teeth, 1.0.1. 

The animal has no proper gill, but Mr. Huxley has observed 
two ciliated circles surrounding the body, as in the larva of 
Pneumodermon. 

Distribution, 4 species. Atlantic and Pacific. 

Sub-genus. Psyche, Rang. (Halopsyche, Bronn.) P. globulosa, 

* Creseis Sedgwicki, Forbes, is an orthoceras with very thin septa, belonging to the 
eame group with (Conularia) teres, Sby. Tentaculites, Schl. is anneUidous. (Salter.) 

t Carboniferous limestone, Brit. Belgium. 

t This name had been previously employed for four different genera of plants and 
animals. 




PTEEOPODA. 851 

PL XTV. , Fig. , 38. Animal globular, with two simple OYal fins. 
Distribution, 1 species. Off Newfoundlaud 

Cymbxtlia, Peron and Lesueur. 

Etymology, diminutive of cymha, a boat. 

Type, 0. pi-oboscidea, PL XIV., Pig, 39 (after Adams). 

Shell cartilaginous, slipper-shaped, pointed in front, trun- 
cated posteriorly ; aperture elongated, yentral. 

Animal with large rounded fins connected ventrally by an 
elongated lobe ; mouth furnished with minute tentacles; lingual 
teeth 1.1.1 ; stomach muscular, armed with two sharp plates. 

Distribution, 3 species, Atlantic, Mediterranean, Indian 
Ocean. 

TiEDEMAJfisriA, Chiaje. 

Type, T. Neapolitana, PL XIY., Fig. 40. 

Named after Fr. Tiedemann. 

Animal naked, transparent, fins united, forming a large 
bounded disk ; mouth central ; tentacles elongated, connate ; 
eye-tubercles minute. Larva shell-bearing, 

Distributipri, 3 species. Mediterranean, Australia,, 

Family II.— Limacintdje. 

Shell minute, spiral, sometimes operculate. 

Animal with fins attached to the sides of the mouth, and 
united ventrally by an operculigerous lobe ; mantle-cavity 
opening dorsally ; excretory orifices on the right side, 

The shells of the true limacinidae are sinistral, by which they 
may be known from the fry of Atlanta, Carinaria, and most 
other Gasteropods. 

LiMACiNA, Cuvier 

Etymology, lim.acina, snail-like. 

Synonym, Spiratella, Bl. 

Example, L. antarctica (drawn by Dr. Joseph Hooker), 
rLXIY.,Fig. 41. 

Shell sub-globose, sinistrally spiral, umbilicated ; whorls 
transversely striated ; umbilicus margined ; no operculum. 

Animal with expanded fins, notched on their ventral margins ; 
operculum lobe divided ; lingual teeth 1.1.1. 

Distribution, 2 species. Arctic and Antarctic Seas; gre- 
garious. 

Spirialis, Eydoux and Souleyet. 
Example, S. bulimoides, PL XIV., Fig. 42. 



352 MAKTTAL OF THE MOLLtTSCA. 

Synonyms, Heterofusus, Fleming. Heliconoides, D'Orbigny. 
Peracle, Forbes. Seaea, Ph.. 

Shell minnte, byaline, sinistrally spiral, globose or turreted, 
smooth, or reticulated ; operculum thin, glassy, semilunar, 
slightly spiral, with, a central muscular scar. 

Animal with narrow, simple fins, united by a simple, trans- 
verse operculigerous lobe ; mouth central, with prominent lips. 

Distribution, 12 species. Greenland and Norway to Capo 
Horn, Indian Ocean, Pacific. 



? Cheletropis, Forbes. 

Etymology, chele, a claw, and tropis, a keel. 

Synonym, Sinusigera, D'Orbigny. 

Ttjpe, 0. Huxleyi, PL XIV., Fig. 43. 

Shell dextrally spiral, imperforate, double- keeled ; nucleus 
sinistral ; aperture channelled in front ; peristome thickened, 
reflected, with two claw-like lobes. 

Animal gregarious in the open sea. 

The species comprised in this and the following genus are 
young gasteropods. (See pp. 212, 225.) 

Distribution, 2 species. South America and South-east 
Australia. 



Another minute spiral shell may be noticed here : — 

Macgillive,atia, Forbes. 

Named after its discoyerer, the naturalist to H.M.S. Battle" 
snake. 

Type, M. pelagica, PL XIV., Fig. 44. 

Shell minute, dextrally spiral, globular, imperforate, thin, 
horny, translucent ; spire obtuse ; aperture oblong, entire ; 
peristome thin, incomplete ; operculum thin, horny, concentric, 
nucleus sub-external. 

Animal with 4 long tentacles, mantle with a siphonal process ; 
foot expanded, truncated in front, furnished with a float after the 
manner of lanthina ; lingual dentition closely resembling 
Jeffreysia. 

Distribution, 3 species. Taken in the towing-net off Capo 
Eyron, East coast of Australia, 15 miles from shore, floating, 
and apparently gregarious. (J. Macgillivray.) Mindoro, North 
A.tlantic. (Adams.) 



pteropoda. ^..53 

Section B. — Gymnosomata, B1. 

Animal naked, without mantle or shell ; head distinct ; £ns 
attached to the sides of the neck ; gill indistinct. 

Family III. — Cliidje. 

Body fusiform ; head with tentacles often supporting suckers ; 
foot small, but distinct, consisting of a central and posterior 
lobe ; heart opistho-hranchiate ; excretory orifices distant, on the 
right side; lingual teeth (in Clio) 12.1.12, central wide, denti- 
culated, uncini strongly hooked and recurved. 

Clio (L.),* MiiUer. 

Etymology, Clio, a sea-nymph. 

Synonym, Clione, Pallas. 

Type, 0. borealis, PI. XIY., Pig. 45. (C. caudata, L., part.) 

Head with 2 eye tubercles and 2 simple tentacula; mouth 
with lateral lobes, each supporting 3 conical retractile processes, 
furnished with numerous microscopic suckers ; fins ovate ; foot 
lobed. In swimming, the Clio brings the ends of its fins almost 
in contact, first above and then below. (Scoresby.) 

Bistrihution , 4 species. Arctic and Antarctic Seas, Norway, 
India. 

Suh-genus ? Cliodita (fusiformis), Quoy and Gaimard. Head 
supported on a narrow neck ; tentacles indistinct. 4 species. 
Cape, Amboyna. 

PNEUMODERMOisr, Cuvier. 

Etymology, Pneumon, lung (or gill), derma, skin. 

Type, P. violaceum, PI. XIY., Pig. 47. 

Body fusiform ; head furnished with ocular tentacles ; lingual 
teeth 4.0.4 ; mouth covered by a large hood supporting two 
small, simple, and two large acetabuliferous tentacles, suckers 
numerous, pedicillate, neck rather contracted ; fins rounded ; 
foot oval, with a pointed posterior lobe; excretory orifice 
situated near the posterior extremity of the body, which has 
small branchial processes, and a minute rudimentary shell 

* This name was employed by Linneeus for all the Pteropoda then known; his 
definition is most suited to the " northern clio,'' probably tlie only species with which 
he was personally acquainted. The first species enumerated in the Syst. Nat. is 
C. caudata, and reference is made to an indeterminable figure iu Brown's Jamaica, 
and to Marten's account of the Spitzbergen mollusc (C. borealis). In cases like this 
the rule is to adopt the practice of tlie next succeeding natui'alist who defines tho 
Umits of the group more exactly. 



354 MAirUAL OP THE MOLLUSC A. 

In the fry of Pneumodermon th© end of the body is encircled 

"with ciliated bands. (Miiller.) 

Distribution, 4 species. Atlantic, India, Pacific Ocean. 

Suh-genus ? Spongiohranchoea, D'Orbigny. S. Australis, PI. 
XIY., Fig. 46. Grill (?) forming a spongy ring at the end 
of the body ; tentacles each with 6 rather large suckers. Distri- 
hution, 2 species. South Atlantic (Fry of Pneumodermon ?). 
Trichocyclus, Eschscholtz, T. Dumerilii, PI. XIV., Fig. 43. 
Animal without acetabuliferous tentacles ? mouth probosidi- 
form ; front of the head surrounded with a circle of cilia, and 
two others round the body. 

? Pelagia, Quoy and Graimard. 

Etymology, Pelagus, the deep sea (not = Pelagia, Peron aijd 
Les.). 

Type, P. alba, PI. XIY., Fig. 49. Amboyna. 

Animal fusiform, truncated in front, rough; neck slightly 
contracted ; fins small, fan-shaped. 

Cymodocea, D'Orbigny. 

Etymology, Kumodoke, a Nereid. 

Type, 0. diaphana, PI. XIV., Fig. 50. 

Animal fusiform, truncated in front, pointed behind ; neck 
slightly contracted ; fins 2 on each side, first pair large and 
rounded, lower pair ligulate ; foot elongated ; mouth probosoi- 
diform. 

Distrihution, 1 species. Atlantic. 



CHAPTER III. 

CLASS IV.— BEACHIOPODA, Cuvier, 1805. 
(= Order PalUo-hrunchiata, Blainville, Prodr. 1814.) 

The Brachiopoda are bivalve shell-fish which difier from the 
ordinary mussels, cockles, &c., in being always equal-sided, and 
never quite equivalve. Their forms are symmetrical, and so 
commonly resemble antique lamps, that they were called 
lampades, or "lamp-shells," by the old naturalists (Meuscheu, 
1787, Humphreys, 1797) ; the hole which in a lamp admits the 
wick serves in the lamp-shell for the passage of the pedicle by 
which it is attached to submarine objects.* 

* The principal modifications of external form presented by these shells are given in 
Plate 15 ; the internal structure of each genxis is illustrated in the woodcuts, which are 



BEACHIOPODA. 



355 



Tiie yalves of tlie Brachiopoda are respectively dorsal and 
ventral ; the ventral valve is usually largest, and has a pro- 
minent beak, by which it is attached, or through ■which the 
organ of adhesion passes. It is sometimes perforated, as in the 
Terebratulidae. The dorsal, or smaller valve, is always free 
and imperforate. The valves are articulated by two curved 
teeth, developed from the margin of the ventral valve, and 
received by sockets in the other ; this hinge is so complete that 
the valves cannot be separated without injury.* A few genera 
have no hinge ; in Crania and Discina the lower valve is flat, 
the upper like a limpet ; the valves of Lingula are nearly 
equal, and have been compared to a duck's bill. (Petiver.) 

Ventral valve. 




Dorsal valve. 
Fig. 145. Muscular system of TerebratulaA 
a a, adductor-muscles ; r, cardinal-muscles ; x, accessory cardinals ; p, ventral 
pedicle-muscles ; jDf, dorsal pedicle-muscles; z, capsular-muscles ; q, rriputh; v, vent: 
I, loop ; t, dental socket. 

This and several other points of dijEference seem to show the 

propriety of adopting the proposal made by Deshayes in 1836 

of dividing the Brachiopods into two great groups, the one 

having articulated, the other non-articulated valves. In the 

first, moreover, the valves are opened by muscles acting on the 

cardinal process of the dorsal valve, while in the latter the valves 

are opened by the pressure of the fluid in tlje perivisceral cavity. 

This difierence is accompanied by a striking variation in the 

the same with those in Mr. Davidson's Introduction, and in the British Museum 
Catalogue. They are from original studies by the author, unless otherwise stated. 

* The largest recent Terebratula cannot be opened more than -1- of an inch, except 
by applying force. 

t Waldheimia Australis, Quoy. -f-. From a drawing by Albany Hancock, Esq. 



356 MA]!^TJAL OF THE MOLLUSCA. 

arrangement of the muscles. The articulated group possess an 
anal aperture ; the unarticulated none. (Hancock.)* 

The valves are both opened and closed by muscles ; those 
which open the shell [cardinales] originate on each side the 
centre of the ventral valve, and converge towards the hinge- 
margin of the free valve, behind the dental sockets, where 
there is usually a prominent cardinal process. The teeth form 
the fulcrum on which the dorsal valve turns. The adductor 
muscles are four in number, and quite distinct in Crania and 
Discina ; in Lingula the posterior pair are combined, and in 
Terebratula the four muscles are separate at their dorsal 
terminations, but united at their insertion in the centre of the 
larger valve. The pedicle is fixed by a pair of muscles (each 
doubly- attached) to the dorsal hinge-plate, and by another 
pair to the ventral valve, outside the cardinal muscles. f 

In the Terebratulidse and the other Brachiopods having 
articulated valves the muscular system consists of 3 pairs of 
muscles which act directly on the valves, and of 3 pairs which 
connect the shell, and adjust it with respect to the peduncle. 
In the unarticulated Brachiopods, such as Lingula, the 
muscles are more complicated than in the former group ; three 
pairs of protractor muscles keep the valves together, and thus 
compensate for the absence of the hinge and condyles, which 
help to form this function in the articulated group ; they are so 
arranged as to co-operate in preventing any displacement of 
the valves in any direction. Hence the term sliding-muscles 
which they have received is inappropriate, since they prevent 
any sliding action. In the Lamellibranchs the sliding of the 
valves is admirably guarded against by means of hinges with 
teeth and sockets ; in Brachiopods the same end is apparently 
obtained by means of muscles. It has, therefore, been pro- 
posed to substitute the ievxn^adjustor iov protractor, and retractor 
for sliding as applied to these muscles. The following table 
shows the names in general use, and those proposed by Mr. 
Hancock : — 

Names in use. Names proposed. Homologous muscles in 

Unarticulated brachiopods. articulated bracliiopoda. 

Ant. retractors. Ant. occlusors. Ant. occlnsors. 

Ant. adductors. Post. „ Post, occlusors. 

■ Post. „ Divaricators. Accessory divaricators. 

* Philosophical Transactions. 1858. 

t The muscular sj'-stem of Terebratula presents a considerable amoimt of rescai- 
.blnnce to that of Modiola (Fig. 214) ; the anterior and posterior pedal muscles may be 
compared to the dorsal and vcnti-al pedicle muscles. 



BrvACHIOPODA. 357 

Names in use. Names proposed. Homologous muscles in 

Unarticulated bracliiopods. articulated bracliiopods. 

Cent, protractors. Cent, adjustors. ) ,^ , . 

Extr. „ Extr. „ i Vent, adjustors. 

Post, retractors. Post. „ Dorsal „ 

Capsular. Peduncular. Peduncular. 

Ant. parietals. 

Post parietals. 

Tlie mnscles are remarkably glistening and tendinous, except 
at their exj)anded ends, wMch. are soft and fleshy. They are, 
with few exceptions, non-striated. In the posterior adductors 
of Waldheimia transverse striations are well displayed. Their 
impressions are often deep, and always characteristic ; but diflB.- 
cult of interpretation from their complexity, their change of 
position, and the occasional suppression of some and combina- 
tion of others. * There may be considerable changes in arrange- 
ment of muscles without any important change in the internal 
structure. Thus in Waldheimia cranium there are six muscular 
impressions in the dorsal yalve ; in W. australis there are only 
four, the other two muscles being attached to the hinge-plate, 
not to the yalve. The valve and hinge -plate are never found 
together, and it is, therefore, probable that in the fossil species, 
the shells of which are found without hinge-plates, the muscles 
may have been arranged as in W. cranium. 

On separating the valves of a recent Terebratida, the diges- 
tive organs and muscles are seen to occupy only a very small 
space near the beak of the shell, partitioned off from the general 
cavity by a strong membrane, in the centre of which is placed 
the animal's mouth. The large cavity is occupied by the 
fringed arms, which have been already alluded to (p. 5) as 
the characteristic organs of the class. Their nature will be 
better understood by comparing them with the lips and labial 
, tentacles of the ordinary bivalves (pp. 18, 21, and Fig. 208, p,^?) ; 
they are, in fact, lateral prolongations of the lips supported 
on muscular stalks, and are so long as to require being folded 
or coiled up. In Rliynchonella and Lingula the arms are spiral 
and separate ; in Terebratula and JDiscina they are only spiral 
at the tips, and are united together by a membrane, so as to 
form a lobed disk. It has been conjectured that the living- 
animals have the power of protruding their arms in search of 
food ; but this supposition is unlikely, since in many genera 
they are supported by a brittle skeleton of shell, while the 

* Professor King has shown that the compound nature of a muscular impression is 
often indicated by the mode in which the vascular' markings proceed from it (as in 
Figs. 176, 181). 



u08 MANUAL OF THE MOLLTJSCA. 

food is Obtained by means of cujTents created by cilia* 
Lingula may have the power of slightly extending the arms. 
The internal skeleton consists of two spiral processes in the 
S'piriferidce (Fig. 168), whilst in Terehratula and Thecidium it 
takes the form of a loop, which supports the brachial mem- 
brane, but does not strictly follow the course of the arms. The 
mode in which the arms are folded is highly characteristic of 
the genera of Brachiopoda; the extent to which they are sup- 
ported by a calcareous skeleton is of less importance, and 
liable to be modified by age. That margin of the oral arms 
which answers to the lower lip of an ordinary biyalve, is 
fringed with long filaments {cirri), as may be seen even in dry 
specimens of recent Terehratidoe. In some fossil examples the 
cirri themselves were supported by slender processes of shell ; * 
they cannot, therefore, be yibratile organs, but are probably 
themselves covered with microscopic cilia, like the oral ten- 
tacles of the ascidian polypes {cilio-h-achiata of Farre). The 
anterior lip and inner margin of the oral arms is plain, and 
forms a narrow gutter along which the particles collected by 
the ciliary currents may be conveyed to the mouth. The object 
of the folding of the arms is obviously to give inci'eased surface 
for the disposition of the cirri. 

The mouth conducts by a narrow oesophagus to a simple 
stomach, which is surrounded by the large and granulated 
liver; the intestine of Lingula is reflected dorsally, slightly 
convoluted, and terminates between the mantle lobes on the 
fight side (Fig. 202). In Orhicida it is reflected ventrally, and 
passes straight to the right, ending as in Lingula. In Terehra^ 
tula, Bhynchonella, and probably all the articulated Brachiopodaj 
the intestine is simple and reflected ventrally, passing through 
a notch or foramen in the hinge-plate, and ending behind the 
ventral insertion of the adductor muscle (Fig. 145, v.)t 

The circulatory system is far less complex than was formerly 
supposed, and does not difler greatly from the same system in 
the Tunicata. The heart is placed on the dorsal surface of the 
stomach, and consists of a simple, unilocular, pyriform vesicle 
without any auricle. From it the blood is propelled through 

* Spirifera rostrdta and Terehratula pectunculoides, in the Sritish Museum. 

t The position at which the intestine terminates in the Terebratulee and JRhyn- 
chonellcB, seems to necessitate the escape of the feeces by the umbonal opening ; in 
these extinct genera wliich have the foramen closed at an early age, there is still an 
opening between the valves (e. g. in Uncites) which has been mistaken for a bj'ssal 
notch. Mr. Hancock has carefully dissected several species of these genera without 
detecting any anal aperture. Filling the intestines with injections was tried, but no 
outlet could be discovered. 



BRACHIOPODA. 859 

foTir cliannels to tlie organs of reproduction and to tlie mantle ; 
and its jB.ow is probably assisted by a number of subsidiary 
pulsatile vesicles situated on tbe main arterial trunks. It then 
courses throu.£j:h the plexus of lacunes in the pallial sinuses and 
lobes ; turns back tbrougb the lacunes of the parietes into the 
system of visceral lacunes. It probably enters the liver, and 
ultimately finds its way back into the heart through the 
branchio- systemic vein. There is; however, another and more 
important blood current, which traverses the whole length of 
the brachial canal, and penetrates to the extremities of the 
cirri, before it joins the current returning from the visceral 
lacunes and fiows with it into the branchio-systemio vein. 
The blood which has passed through the brachial canal is 
far more highly oxygenated than the blood which has flowed 
through the pallial membranes. There seems to be strong 
evidence that the so-called arms are really the gills or respira- 
tory organs of the mollusc. They also serve to bring food 
to the creature's mouth by the means before noticed. The 
mantle is an accessory breathing-organ. It attains its highest 
development as such in Lingula, but even in this genus the 
brachial apparatus performs the chief part in oxygenating the 
blood. 

There is another system of canals which take their rise from 
the visceral cavity. What its function is has not been deter- 
mined ; it is not the blood system as was formerly imagined, 
and has no connection with it. The perivisceral cavity and the 
visceral lacunes which diverge from it may, it is thought, be 
homologous to the water-vascular system in Polyzoa, the 
function of which is probably to evacuate the effete nitro- 
genised products which have been eliminated from the blood. 
Consequently it would perform the ofiices both of the kidney 
and the renal organs. 

The generative organs occupy the great pallial sinuses, and 
probably both sexes are combined in one individual. In the 
articulated Brachiopods the ovaries and testes are placed in the 
mantle; but in Lingula and Discina they occur in the peri- 
visceral chamber. The ova escape into the oviducts (regarded 
by Ouvier and others as hearts), which open externally, and 
have nothing to do with the vascular system. In Rhynchonella 
there are four oviducts, but in most, if not all the other 
Brachiopods, there are only two. In Terebratulidse they are 
divided into two portions, called the auricle and ventricle by 
Professor Owen. Mature eggs have been found in large numbers 
in the perivisceral chamber and in the oviducts. Eecent 



360 MANUAL OF THE MOLLUSCA. 

Discmce often have minute fry attaclied to their yalves, and Mr. 
Suess, of Vienna, has noticed a specimen of the fossil Stringo- 
cepJialus, which contained numerous embryo shells. 

As yet we know little respecting the development of the 
SracMopoda, but there can be no doubt that in their first stage 
they are free and able to swim about until they meet with a 
suitable position. It is probable that in the second stage they 
all adhere by a byssus, which in most instances becomes con- 
solidated, and forms a permanent organ of attachment. Some 
of the extinct genera (e.g. Bpirifera and StropJwmena) appear 
to have become free when adult, or to have fixed themselves by 
some other means. Four genera, belonging to very distinct 
families, cement themselves to foreign objects by the substance 
of the ventral valve. 

The nervous system exhibits a state of development but little 
superior to what is found in Ascidians. No special organs 
of sense have been detected. The red spots in the mantle, sup- 
posed by some to be rudimentary eyes and ears, are probably 
the glands situated at the base of the setae. 

The Lamp-shells are all natives of the sea. They are found 
hanging from the branches of corals, the under sides of shelving 
rocks, and the cavities of other shells. Specimens obtained 
from rocky situations are frequently distorted, and those from 
stony and gravelly beds, where there is motion in the waters, 
have the beak worn, the foramen large, and the ornamental 
sculpturing of the valves less sharply finished. On clay beds, as 
in the deep clay strata, they are seldom found ; but where the 
bottom consists of calcareous mud they appear to be very 
abundant, mooring themselves to every hard substance on the 
sea-bed, and clustering one upon the other. 

Some of the Brachiopoda appear to attain their full growth in 
a single season, and all probably live many years after becoming 
adult. The growth of the valves takes place chiefly at the 
margin ; adult shells are more globular than the young, and 
aged specimens still more so. The shell is also thickened by the 
deposit of internal layers, which sometimes entirely fill the 
beak, and every portion of the cavity of the interior which is 
not occupied by the animal, suggesting the notion that the 
creature must have died from the plethoric exercise of the cal- 
cifying function, converting its shell into a mausoleum, like 
many of the ascidian zoophytes. 

The intimate structure of the shell of the BracMopoda has 
been investigated by Mr. Morris, Professor King, and more 
recently by Dr. Carpenter; according to this last observer, 




BEACHIOPODA. 361 

it consists of flattened prisms of considerable length., arranged 
parallel to each other with great regularity:, and obliquely 
to the surfaces of the shell, the interior of which is imbricated 
by their out-crop (Fig. 146). This struc- 
ture is found only in the Bhynchonellidce ; 
but in most — perhaps all the other 
BracMopoda* — the shell is traversed by 
canals from one surface to the other, 
nearly vertically, and regularly, the dis- 
tance and size of the perforations varying 
with the species. Their external orifices 
are trumpet-shaped, the inner often very 

It ,• 1.-I -u-n J. J. ^ Fig. 146. Terebratula. 

small ; sometimes they biiurcate towards 

the exterior, and in Crania they become aborescent. The canals 
are occupied by coecal processes of the outer mantle-layer, f 
and are covered externally by a thickening of the epidermis. 
Mr. Huxley has suggested that these coeca are analogous to 
the vascular processes by which in many ascidians the tunic 
adheres to the test; the extent of which adhesion varies in 
closely allied genera. The large tubular spines of the Produc- 
tidce must have been also lined by prolongations of the mantle ; 
but their development was more probably related to the main- 
tenance of the shell in a fixed position, than to the internal 
economy of the animal. (King.) Dr. Carpenter states that 
the shell of the BracMopoda generally contains less animal 
matter than other bivalyes ; but that Discina and Lingula con- 
sist almost entirely of a horny animal substance, which is 
laminar, and penetrated by oblique tubuli of extreme minute- 
ness. He has also shown that there is not in these shells that 
distinction between the outer and inner layers, either in struc- 
ture or mode of growth, which prevails among the ordinary 
bivalves ; the inner layers only difier in the minute size of the 
perforations, and the whole thickness corresponds with the 
outer layer only in the LameUihranchiata. The loop, or 
brachial processes, are always impunctate. Mr. Hancock's 
researches would tend to show that these conclusions are gene- 
rally correct, but not entirely so. " When the shell is dissolved 

* The fossil shells of the older rocks are so generally pseudomorpbous, or partake of 
the metamorphic character of the rock itself, that it is difficult to obtain specimens in 
a state fit for microscopic examination. 

t Called the "lining membrane of the slieU," by Dr. Carpenter. (Davidson Intr. 
Mon. Brach. ) M. Queckett states that the perforations are closed externally by disks, 
surrounded by radiating lines, supposed to indicate the existence of vibratue cilia in 
tli6 living specimens. 

H 



362 ' MAlfUAL OF THE MOLLTJSCA. 

in acid tlie free border [of the mantle] wliicli projects beyond tbe 
marginal fold, and which, is applied to the extreme edge of the 
shell, can be examined with advantage. The pallial cceca are 
then completely exposed appended to the membrane in various 
stages of development, and the spaces between them are found 
studded all over with ratiier large, clear, oval, cell-like spots, which 
are arranged with considerable regularity in rows, so that those 
in the approximate rows alternate. These spots apparently 
correspond to the bases of the prismatic columns of the shell ; 
and if it be allowed that they represent spaces in which cal- 
careous granules had been accumulated, it is easy to understand 
how the fibrous or columnar structure is formed. A succession 
of layers of such accumulated granules deposited one after the 
other would result in the peculiar shell formation of the 
Brachiopoda." The extremities of the prisms are not visible 
on the external surface, but in the young individual of some 
species, as Terebratula caput-serpentis, there is a thin layer of 
calcareous matter, which seems to show that in some Brachio- 
pods the shell is composed of two layers of shell, having a 
diflPerent structure, as in the case of the Conchifera. 

Of all moUusca the Brachiopoda enjoy the greatest range both 
of climate, and depth, and time ; they are found in tropical 
and polar seas, in pools left by the ebbing tide, and at the 
greatest depths hitherto explored by the dredge. At present 
only 84 recent species are known ; but many more will probably 
be found in the deep sea, which these shells mostly inhabit. 
The number of living species is already greater than has been 
discovered in any secondary stratum, but the vast abundance of 
fossil specimens has made them seem more important than the living 
types, which are still rare in the cabinets of collectors, though 
far from being so in the sea. Above 1,800 extinct species of 
Brachiopoda have been described, of which more than half are 
found in England. They are distributed throughout all the 
sedimentary rocks of marine origin from the Cambrian strata 
upwards, and appear to have attained their maximum of specific 
development in the Silurian age.* Some species {\!ik.Q Atrypa 
reticularis) extend through a whole "system" of rocks, and 
abound equally in both hemispheres; others (like Spirifera 
striata) range from the Cordillera to the Ural mountains. One 
recent Terebratula [caput-serpentis) made its appearance in the 
Miocene Tertiary ; whilst others, scarcely distinguishable from 

* The number of Silurian species amounts to 690 ; but these were not all living at 
one time, they were obtained from a whole series of deposits, representing a succession 
gf jieriodfl. 



BEACHIOPODA. 

ii, are found in tlie Upper Oolite and throngliout the Chalk 
series and London Clay.* 

Eamilt I. — ^Teeebeatulidjs. 

Shell minutely punctate ; usually round or oval, smooth or 
striated ; ventral valve with a prominent beak and two curved 
hinge-teeth ; dorsal valve with a depressed umbo, a promi- 
nent cardinal process between the dental sockets, and a slender 
shelly loop. 

Animal attached by a pedicle, or by the ventral valves ; oral 
arms united to each other by a membrane, variously folded ; 
sometimes spiral at their extremities. 





A '^^ -^ B 

Fig. 147. Terebratula vitrea, Born. 

Terebhattjla, (Llhwyd.) Brug. Lamp-shell. 

Etymology, diminutive of ferehratus, perforated. 

Synonyms, Lampas, Humph. Gryphus, Muhlfeldt. Epithyris, 
Phil. 

Types, T. maxillata, PL XY., Fig. 1. (= Ter. minor-sub- 
rubra, Llhwyd. Anomia terebratula, L.) T. vitrea. Fig. *±7. 

Shell smooth, convex ; beak truncated and perforated ; 
foramen circular ; deltidium of two pieces frequently blended ; 
loop very short, simple, attached by its crura to the hinge-plate 
(Fig. 147, A). 

Animal attached by a pedicle ; brachial disk tri-lobed, centre 
lobe elongated and spirally convoluted (Fig. 147, B). The 
young of T. diphya (Pygope of Link) has bi-lobed valves 
(PI. XV., Fig. 2) ; when adult the lobes unite, leaving a round 
hole through the centre of the shell. 

* The author has to acknowledge his obligation to Mi*. Davidson for the use of 
the notes, drawings, and specimens, assembled during the preparation of his great 
work on the " British Fossil Brachiopoda,'' printed for the Palaeontographical 
Society; to which work the student is referred for more copious descriptions and 
illustrations. 

r2 



364 



MANUAL OF THE MOLLUSCA. 



Distribution, 3 species. Mediterranean 90 — 250 fatKoms on 
nullipore mud. (Forbes.) Vigo Bay ; Falkland Islands. 
Fossil, 126 species. Devonian — . World-wide. 
Sub-genera. Terebratulina (caput-serpentis), D'Orbigny. (PI. 



XY., 




Shell finely striated, auriculate, 




Fig. 148. Dorsal valve. Animal, ^. 

deltidium usually rudimental ; foramen incomplete ; loop 
short, rendered annular in the adult by the union of the oral 
processes. Distribution, 6 species. United States, Norway, 
Cape, Japan. 10 — 120 fathoms. Fossil, 22 species. Oxfordian — . 
United States. Europe. 

Waldheimia (australis). King. PI. XY., Pig. 4 (p. 5, Pigs. 
5, 6), Pigs. 145, 149, 150. 

i 
— Z 





rig. 149. Dorsal valve. 



Fig. 150. Ventral valve. 



Fig. 149. J, cardinal process ; t\ dental sockets ; p, hinge-plate ; 5, septum ; c, crura 
of the loop ; I, reflected portion of the loop ; m, quadruple abductor-impression. 

Fig. 150. /, foramen ; d, deltidium ; t, teeth ; a, single abductor impression ; r, car- 
dinal muscles ; x, accessory muscles ; p, pedicle muscles ; v, position of the vent ; z, 
attachment of pedicle- sheath. 

Shell smooth or plaited, dorsal valve frequently impressed; 
foramen complete ; loop elongated and reflected ; septum (s) of 
smaller valve elongated. Distribution, 9 species. Norway, 
Java, Australia, California, Cape Horn. Low water — 100 



BRACHIOPODA. 



365 




rig. 151. Terehratella. 



fathoms. Fossil, 90 species. Carb — . SoutL. America, Europe. 
Eudesia (cardium), King, includes 1 recent a^d 6 fossil species 
which are sharply plaited. T. impressa (PI. XY., Fig. 5) is 
the type of a group which has the external shape of Terehratella. 
Meganteris, Suess, 1856. Terebratula Archiaci, Yern. Devo- 
nian, Asturias. Shell with a long, reflected, internal loop. 

Terebeatella, D'Orbigny. 

Type, T. dorsata, Gmel. (= Magel- 
lanica, Chemn.) PL XY., Fig. 7. Fig. lol. 

Shell smooth or radiately plaited ; dorsal 
valve longitudinally impressed ; hinge- 
line straight, or not much curved; beak 
with a flattened area on each side of the 
deltidium ; foramen large ; deltidium in- 
complete ; loop attached to the septum (s). 

Animal like Terebratula ; the spiral lobe 
of the brachial disk becomes very 
diminutive in some species, and is 
obselete in Morrisia and T. Cumingii. 
Distribution, excluding sub-geiiera, 
25 species. Cape Horn, Yalparaiso 
(90 fathoms), New Zealand, Japan, 
Ochotsk, Spitzbergen, Labrado*r. 
Fossil, 16 species. Lias—. United ^ig- 152. Ter. Evansii, Dav. 
States, Europe. In T. crenulata and Evansii (Fig. 152) the 
dorsal septum sometimes projects so far as to touch the oppo- 
site valve, but in other examples it remains undeveloped. 
(Davidson.) 

Sub-genera. Trigonosemus (elegans), Konig. Synonyms, Del- 
thyridsea (pectiniformis), M'Coy. Fissirostra, D'Orbigny. 
Example, T. Palissii, PL XY., Fig. 8. Shell finely plaited, 
beak prominent, curved, with a narrow apical foramen ; cardinal 
area large, triangular ; deltidium solid, flat ; cardinal process 
very prominent. Distribution, 5 species. Chalk, Europe. 

Lyra (Meadi), Cumberland, Min. Con. 1816. PL XY.,Fig. 6. 
Synonyms, Terebrirostra, D'Orbigny. Ehynchora, Dalman.* 

* The name Rhynchora was given by Dalman to the Ter. costata. Wahl, = T. 
pectinata, L.) on the supposition that it was identical with Sowerby's T.Lyra; and 
aa no specimen could be found with a long beak, an artificial one was manufactured 
for it, of which there is a cast in the British Museum. The second species of " Ehyn- 
chora," Ter. spatulaia, Wahl., has no beak whatever: in shape it is like an Argiope, 
but measures an inch each way. The ventral valve is a simple bent plate with the 
teeth at the angles ; the dorsal valve is flat, with a very wide hinge-plate, and sockets 
at the angles, whilst a single septum projects from the centre, with portions of a lotij* 
attached. 




mQ 



MANUAL OF THE MOLLTJSCA. 



Shell omamented with rounded ribs ; beak very long, divided 
lengthwise internally by the dental plates ; loop doubly 
attached ? Distribution, 4 species cretaceous. Europe. Three 
species of similar form are found in the Trias of St. Cassian. 

Magas (pumila), Sby. Eig. 153. 
Shell smooth, conspicuously punc- 
T- tate, dorsal valve impressed, fora- 
men angular, deltidium rudimen- 
tary; internal septum (s) prominent, 
touching the ventral valve ; reflected 
portions of the loop disunited (Z). 
3 species. U. Green-sand — Chalk. 
Europe. Distribution, 2 species. 
The recent Ter. Cumingii, of New 
but has the 




rig. 153. M. Pumila.^ 



New Zealand ; Canaries. 

Zealand, resembles Bouchardia externally, 

diverging processes of the loop as in Magas. 




Fig. 154. B. TuUpa, Bl.* 

Bouchardia (tulipa), Davidson, Eig. 164. Beak prominent, 
\rith a minute apical foramen (/) ; deltidium blended with the 





Fig. 155. Dorsal valve. t 

shell {d) ; apophysis anchor-shaped, the septum (s) being fur- 

* The muscular impressions in Bouchardia have been compared with those of Ter. 
Cumingii, of which the animal is known. The large impressions (r) in the disk of the 
ventral valve appear to be formed by the cardinal muscles ; a, by the adductor ; p, by 
tlie pedicle muscles. 

t Fig. 155. c, loop ; /, pedicle notch ; o, the ovaries. From the originals in Mr. 
Davidson's collection ; magnified ten diameters. 



BEACHIOPODA. 



367 



nislied with, two short lamellr©. Distribution, 3 species. Brazil, 
13 fathoms. New Zealand, South Australia. 

Morrisia (anoinioides, Scacchi), Davidson. Eig. 155. Shell 
minute, conspicuously punctate ; foramen large, encroaching 
equally on both valves ; hinge area small, straight ; loop not 
reflected, attached to a small forked process in the centre of the 
valve. Animal with sigmoid arms, destitute of sjoiral termina- 
tions ; cirri in pairs. Distribution, 3 species. Mediterranean. 
95 fathoms. (Forbes.) Fossil, 4 species. Chalk — . Europe. 





Fig. 156. Dorsal valve with animal.-|- Fig. 157. Dorsal valve. 

Kraussia (rubra), Dav. Cape. Fig. 157. K. Lamarckiana, 
Dav. Australia. Fig. 156. Shell transversely oblong ; hinge- 
line nearly straight ; beak truncated, laterally keeled ; area 
flat; foramen large, deltidium rudimentary; dorsal valve 
longitudinally impressed, furnished inside with a forked pro- 
cess rising nearly centrally from the septum ; interior often 
strongly tuberculated. The apophysis is sometimes a little 
branched, indicating a tendency towards the form it attains in 
Eig. 158. Animal with rather small oral arms, the spiral lobe 
very diminutive. Distribution, 6 species. South Africa, Sydney, 
New Zealand ; low water to 120 fathoms. 





Fig. 158. 



Dorsal valve. 



fMegerlia (truncata), King, 1850. PI. XY., Fig. 9. Eig. 
158. Loop trebly attached ; to the hinge-plate by its crura, and 
to the septum by processes from the diverging and reflected 
portions of the loop. Distribution, 3 species. Mediterranean, 
Philippines. These species belong to the same natural group 
with Kraussia. Fossil, 7 species. Chalk — . 



368 



MANUAL OF THE MOLLUSCA.l 



? Kingena (lima), Dav. Cretaceous, Europe, Guadaloupe. 
Valyes spinulose ; loop trebly attached. 





Fig. 159. Ter. {Kingena) lima, (after Davidson.) 

t, dental sockets ; j, cardinal process ; c, crura ; d, diverging processes of loop , r, re- 
flected portion ; e, tbdrd attacliment of loop ; s, dorsal septum. 

? Ismenia (pectunculus), King. Coral rag, Europe. Yalyes 
ornamented with corresponding ribs ; loop trebly attached. 

? Waltonia (Yalenciennei), Dav., New Zealand. Perhaps 
the fry of Ter. rubicunda, with the reflected part of the loop 
wanting. 

Zellania (Davidsoni), Moore, 1855. [Etymology, Zella, a lady's 
name ?) Shell minute, orthi-form ; texture fibrous ; hinge- 
area short, foramen angular, encroaching on both valves; interior 
of dorsal valve as in Theddium, with a single central septum 
and broad margin. Fossil. Lias — Grreat Oolite. 3 species. 
Britain. 





Tig. 160. Argiope decollata. ^ Fig. 161. A. Neapolitana, Sc* -f- 

Aegiope, Eudes Deslongchamps. 
Etymology, Argiope, a nymph. 
Synonym, Megathyiis, D'Orbigny. 
Type, A. decollata, PI. XY., Fig. 10. Fig. 160, 162. 
Shell minute, transversely oblong or semi-ovate, smooth or 

» Interior of dorsal valves magnified, from tlie originals in Coll. Davidson. 



BEACmoPODA. 



369 



■witli Corresponding ribs ; hinge -line wide and straiglitj witli a 
narrow area to each valve ; foramen large, deltidium rudi- 
mentary ; interior of dorsal valve with one or more prominent, 
sub-marginal septa ; loop two or four-lobed, adhering to the 
septa) and more or less confluent with the valve 




Vig, 162. A. decollata, ^ ; dorsal valve with the animal, from a specimen dredged 
h)' Professor Forbes in the ^gean. The oral aperture is seen in the centre of tlie 
disk. 

Animal with oral arms, folded into two or four lobes, united 
by membrane, forming a brachial disk fringed with long cirri; 
mantle extending to the margins of the valves, closely adherent. 

Distribution, 5 species. North Britain, Madeira, Canaries, 
Mediterranean. 30— lOo fathoms. 

Fossil, 19 species. Oolite — . Europe. 





Tig. 163. Jl radians. Fig. 164. T. Mediterfaneum,* *■ 

ThecIDITJM, Defrance. 
Etymology, Tliekidion, a small pouch. 
Type, T. radians, PL XV., Fig. 11. 
Shell small, thickj punctate, attached by the beak ; hin^e- 

* Dorsal valve vpith the anitoal, magnified. Coll. Davidson. 
R o 



370 



MAKtrAL 01? THE MOLLtTSCA. 



area {h) flat ; deltidium {d) triangular, indistinct ; dorsal valve 
(Fig. 163) rounded, depressed; interior with a broad granulated 
margin; cardinal process prominent, between the dental sockets ; 

oral processes united, forming a 
bridge over the small and deep 
yisceral cavity ; disk grooved for 
the reception of the loop, the 
grooves separated by branches from 
a central septum ; loop often un- 
symmetrical, lobed, and united more 
or less intimately with the sides of 
the grooves ; ventral valve (Fig. 165) 
deeply excavated, hinge-teeth pro- 
minent ; cavities for the adductor 
(a) and pedicle muscles (p) small ; 
disk occupied by two large smooth 
impressions of the cardinal muscles, 
bordered by a vascular line. 

Animal (Fig. 164) with elongated 
oral arms, folded on themselves and fringed with long cirri ; 
mantle extending to the margin of the valves and closely ad- 
herent ; epidermis distinct. 

T. radians is the only unattached species, it is supposed to be 
fixed by a pedicle when young. (D'Orbigny.) 




Fig. 165. 



T. radians. -^ . 




Dorsal valve. Fig. 166. Profile.* 

a, adductor ; c, crura ; I, loop ; J^ cardinal process ; p^ hinge-plate ; s, dorsal septum ; 

V s, ventral septum ; t, dental sockets. 

T. hieroglypMcum^ PI. XV., Fig. 12, has a very complicated 
* The loop (wliich WBB discovered by Professor King) has a distinct suture in Iho 




BEICHIOPOBA. 371 

interior ; whilst in several others there are but two hrachial 
lobes. The Liassic species form the subject of a monograph by 
M. Elides Deslongchamps ; they are often minute, and attached 
in numbers to sea-urchins, corals, and terebratulse. 

Distrihutiorty 1 species. Mediterranean. 

Fossil, 34 species. Trias—. Europe. 

? Steingocephaltjs,, Defrance. 

Etymology, Strinx {stringos), an owl, cephale, the head.* 
Type, S. Burtini, PI. XV., Fig. 13. Figs. 166, 167. Devonian, 
Europe. 

Shell punctate ; sub-orbicular, with a prominent beak ; ventral 
valve with a longitudinal septum (v s) in the middle ; hinge- 
area distinct ; foramen large and angular in 
the young shell, gradually surrounded by 
the deltidium, and rendered small and oval 
in the adult ; deltidium composed of three 
elements ;; teeth prominent ; dorsal valve 
depressed, cardinal process (/) very promi- rig. I67.t 

nent, sometimes touching the opposite valve, its extremity 
forked to receive the ventral septum (v s) ; hinge-plate {p) sup- 
porting a shelly loop, after the manner of Argiope. 

Family II. — Spieipehid^. 

Shell furnished internally with two calcareous spiral processes 
{apophyses) directed outwards towards the sides of the shell, and 
destined for the support of the oral arms, which must have 
been fixed immovably; the spiral lamellae are sometimes 
spinulose, indicating the existence of rigid cirri, especially on 
the front of the whorls; valves articulated by teeth and 
sockets. 

SpmiFEBA, Sowerby. 

Type, S. striata, Sby., Fig. 168. 

Synonyms, Trigonotreta. Konig. Choristites, Fischer. Del- 
thyris, Dalman. Martinia, &c., M'Coy. 

middle ; the dotted lines proceeding from its inner edge are added from a drawing by 
M. Suess, and represent what he regards as shelly processes for supporting a meiu- 
branons disk. They may be portions of spirals, whose outer whorls are confluent. 

* Internal casts of Productus giganteus are called " owl-heads " by quarrymen in 
the North of Eng and. (Sowerby.) 

t Fig. 167. Young shell, magnified four diameters; A, hinge area; b, deltiditim; 
p, pseudo-deltidium. 



;72 



MANUAL OF THE MOLLUSCA. 



Shell impunctate,* transversely oval or elongated, tri-lobed, 
beaked, bi-convex, with a dorsal ridge and ventral furrow ; 
binge-line wide and straight ; area moderate, striated across ; 
foramen angular, open in tbe young, afterwards progressively 





Dorsal valve. 



Fig. 168. 



Ventral valve. 



closed ; ventral valve with prominent binge-teetb, and a central 
muscular scar, consisting of tbe single adductor flanked by two 
cardinal impressions ; dorsal valve with a small cardinal process, 
a divided binge-plate, and two conical spires directed outwards 
and nearly filling tbe cavity of tbe sbell ; crura united by an 
oral loop. Tbe sbell and spires are sometimes silicified in lime- 
stone, and may be developed by means of acid. In S. mosquensis 
tbe dental plates are prolonged nearly to tbe front of tbe ventral 
valve. 

Bistrilution, 220 species. Lower Silurian — Trias. Arctic 
America — Cbili, Falkland Islands, Europe, Cbina, Tbibet, 
Australia, Tasmania. In Cbina tbese and otber fossils are used 
as medicine. 

Sub-genera. Spiriferina, D'Orbigny. S. Walcotti, PI. XV., 
Fig. 14. Shell punctate, external surface spinulose ; foramen 
covered by a pseudo-deltidium ; interior of ventral valve witb a 
prominent septum, rising from tbe adductor scar. Distribution, 
29 species. Carb. — Lower Oolites. Britain, France, Germany, 
Soutb America. 

Cyrtia, Dalman. 0. exporrecta, PL XV., Fig. 15. Shell 
impunctate, pyramidal, beak prominent, area equiangular, 
deltidium witb a small tubular foramen. Fossil, 10 species. 
Silurian — Trias. Europe. In G. buchii, heteroclyta, calceola, 
&c., tbe sbell is punctate. 

Suessia (imbricata), Eudes Deslongcbamps, 1855. (Dedicated 
to M. Suess). Shell ]ike Spirifera; texture fibrous; binge area 
wide as tbe sbell ; foramen deltoid ; large valve witb two 
cardinal septa, and a prominent central septum, supporting a 
little plate ; small valve witb a tri-lobed cardinal process, and 

* Professor King attributes this to metamorpliism ; 5. Deniarlii, Bonch., from the 
Devonian limestone, is ijunctate. (Carpenter.) 



BfiACHIOPOTIA. 



373 



a broad 4-partite Mnge-plate, with, processes from the outer 
angles of the dental sockets ; crura of the spires united by a 



transverse band supporting a small process. 
Upper Lias, Normandy. 



Fossil, 2 species. 



Atkfris, M'Coy. 

Etymology i a, without, thuris, a door* (i.e. deltidium). 

Synonyms, Spirigera, D'Orbigny. Cleiothyris, King (not 
Phil.). 

Types, A. concentrica, Buch. A. Eoissyi, Pigs. 169, 170. 
A. lamellosa, PL XY., Fig. 16. 

Shell impunctate, transversely oval, or sub-orbicular, bi« 
convex, smooth, or ornamented with squamose lines of growth, 
sometimes developed into wing-like expansions (Pig. 170t) ', 




Fig. 169. Interior of dorsal valve. 



Fig. 170. Specimen with fringe. 



hinge-line curved, area obsolete, foramen round, truncating the 
beak, deltidium obsolete ; hinge -plate of dorsal valve with four 
muscular cavities, perforated by a small round foramen, and 
supporting a small complicated loop (?) between the spires ; 
spires directed outwards, crura united by a prominent oral 
loop. 

The foramen in the hinge-plate occupies the situation of the 
notch through which the intestine passes in the recent Bhyn- 
cJionellce; in A. coricentrica a, slender curved tube is sometimes 
attached to the foramen, beneath the hinge-plate. A. tumida 
has the hinge-plate merely grooved, and the byssal foramen is 
angular. 

Fossil, about 70 species. Silurian — Lias. North and South, 
America and Europe. 



* Sometimes employed, incorrectly, in the sense of a 6.ooT-v)ay or for men. 
t The spurious genus Actinoconchus (M'Coy) was founded on this character ; similai' 
expansions are formed by species of Atrypa, Camarophoria, and Producta. 



374 



MAinJAL OF THE MOtLtTSCA, 




S'uh-genus? Merista^ Suess. Ter. scalpnim, Ecemer. (A. 
cassidea, Quenst. Sp. plebeia, Ph.) Silurian 
— 'Devonian. Europe. Shell impunctate, 
dental plates {v) and dorsal septum [d) sup- 
ported by arched plates ("shoe-lifter" 
processes, of King) which readily detach, 
leaving cavities (as in Fig. 171) ; spiral arms 

Fig, 171. Merista. have been observed in all the species. 

Eetzia, King. 

Dedicated to the distinguished Swedish naturalist, Eetzius. 

Type, Ter. Adrieni, Yern. 

Example, E. serpentina, Carb. L., Belgium^ Fig. 172., 

Shell punctate, terebratula-shaped ; beak truncated by a 
round foramen, rendered complete by a distinct deltidium ; 
hinge-area small, triangular, sharply defined; interior with 
diverging shelly spires. 

Fossil, about 50 species. Silurian — Trias. South America, 
United States, Europe. 

Professor King first pointed out the existence of calcareous 
spires in several Terehratuloe of the older rocks, and others have 
been discovered by MM. Quenstedt, De Koninck, and Barrande, 
In form they resemble TerehratuUna, Eudesia, and Lyra. 





Fig. 172. Betzia serpentina, D, K, 



Fig. 173. Uncites gry;f.hus. 



Uncites, Defrance. 
Type, V. gryphus, PI. XY.,. Pig. 17. Fi^ 



173. 



Fossil, Devonian. Europe. 

Shell impunctate ; oval, bi- convex, with a long incurved 
beak ; foramen apical, closed at an early age ; deltidium large, 
concave ; spiral processes directed outwards ; no hinge-area. 

The large, concave deltidium of Uncites so much resembles 
the channel formed by the dental plates of Pentamcrus, that 



BRACSIOPODA* 



375 



Dalman mistook the shell for a member of that genus. The 
discovery of internal spires, by Professor Beyrich, shows that it 
only differs from Retzia in being impunctate and destitute of 
hinge-area. Some of the specimens have corresponding depres- 
sions in the sides of the valves (Pig. 173, ^), formiD.g pouches 
which do not communicate with the interior. 



PaMILY III. — EHYN"CHOKELLrDJE. 

8heU impunctate, oblong, or trigonal, beaked ; ' hinge-line 
curved ; no area ; valves articulated, convex, often sharply 
plaited; foramen beneath the beak, usually completed by a 





Pig. 174. R. nigricans. 



Ventral. 



Fig. 175. 



Dorsal. 



Fig. 174. Dorsal valve with the animal ; a, adductor muscles ; i, intestine. 

Fig. 175. R. psittacea, interiors. 5, septum ; /, foramen ; d, deltidium ; t, teeth; V, 
sockets ; c, oral lamellae ; a, adductor impressions i r, cardinal ; p, pedicle muscles ; 0, 
ovarian spaces. 

deltidium, sometimes concealed; hinge-teeth supported by 
dental plates ; hinge-plate deeply divided, supporting oral 
lamellae, rarely provided with spiral processes ; muscular im- 
pressions grouped as in Terebratula ; vascular impressions 
consisting of two principal trunks in each valve, narrow, 
dichotomising, angular, the principal posterior branches inclos- 
ing ovarian s aces. 

Animal [of Rhynchonella) with elongated spiral arms, directed 
inwards, towards the concavity of the dorsal valve ; alimentary 
canal terminating behind the insertion of the adductor in the 
ventral valve ; mantle not adhering, its margin fringed wit i a 
few short setae. 

EHYiq-cHOKELLA, Pischer. 

Synonyms, Hypothyris, Phil. Hemithyris (psittac3aj, 
D'Orbigny. Acanthothyris (spinosa), D'Orbigny. Cyclothyrii 
(latissima), M'Coy. Trigonella (part), Pischer (not L. nor Dx 
Costa). 



876 



MAKtlAL OF THE MOLLtJSCJ 



Types, B* acuta, PI. XY., Fig. 18; furcillata, Pig. 19? 
spinosa, Pig. 20 ; acuminata, Eig. 176 ; nigricans, Eig. 174 J 
psittacea, Fig. 175 Qj. 5, Fig. 4). 




Ventral aspect* Umbonal aspeot. 

Fig. 1 76. Rh. acuminata, internal casts. 
Fig. 176. Umbonal aspect, with the dorsal valve above (GoU. Professor King). 
Ventral aspect (Coll Professor Morris). A, adductor; E, cardinal; P, pedicle; V, 
Vasculai' ; 0, ovarian impressions. 

Shell trigonal, acutely beaked, usually plaited ; dorsal valye 
elevated in front, depressed at the sides; ventral valve ilattened, 
or hollowed along the centre, hinge-plates supporting two slender 
curved lamellae ; dental plates diverging. 

The foramen is at first only an angular notch in the hinge- 
line of the ventral valve, but the growth of the deltidium usually 
renders it complete in the adult shell ; in the cretaceous species 
it is tubular. In R. acuminata and many other palseozoic 
examples, the beak is so closely incurved as to allow no space 
for a pedicle. Both the recent Rliynchonellce are black ; R, odo- 
plicata of the Chalk sometimes retains six dark spots. 

Distribution, 4 species. R. psittacea, Labrador (low water :), 
Hudson's Bay (100 fathoms), Melville Island, Sitka, Icy Sea. 
R. nigricans, New Zealand, 19 fathoms. 

Fossil, 3.32 species. Lower Silurian — . North and South 
America, Europe, Thibet, China. 

Suh-genera. ? JPoramhonites, Pander. P. sequirostrisj SchL 
Shell impunctate ; surface minutely pitted ; each valve with a 
minute hinge-area and indications of two septa; foramen 
angular, usually concealed. Distribution, 8 species. Lower 
Silurian. Eussia and Portugal. 

Camarophoria, King. T. crumena, Martin (sp.). Figs. 177, 
178. Yentral valve with converging dental plates {d) supported 



BEACHIOrODA. 



377 



on a low septal ridge (s) ; dorsal valve with a prominent septum 
(s) supporting a spoon-shaped central process {v) ; oral lamellae 
long and slender (o). Poramen angular, cardinal process dis- 
tinct (y). Fossil, 9 species. Carb. — Permian (Magnesian lime- 
stone.) Germany and England. 




Fig. 177. laternal cast,* 



Fig. 178. Section. 



Pentamerijs, Sowerby. 

Etymology, pentameres, o-partite. 

Synonym, Gypidia (conchydium), Dalman. 

Type, P. Knigktii, PI. XY., Pig. 22. Pig. 179. 

Shell impunctate, ovate, ventricose, with, a large incurved 
beak ; valves usually plaited ; foramen angular ; no area or 
deltidium ; dental plates (d) converging, trough-like, supported 
on a prominent septum (s) ; dorsal valve with two contiguous 




Longitudinal. 



Fig. 179. 



Transverse section. 



longitudinal septa (s s) opposed to the plates of the other 
valve. 

Oral lamellae have been detected by Mr. Salter in P. liratus ; 

* Ventral side of cast, showing the V-shaped cavity of the dental plates, and the 
impressions of branchial veins, accompanied by arteries (after King), 



378 



MA-NXTAI OF THE MOLLTTSCA. 



ir P. ? hrevirostris (Devonian, Newton) the dorsal valve tas a 
long trough-like process supported by a single low septum. 

Fossil, 52 species. Upper Silurian — Devonian. Arctic 
America, United States, Europe. 

The relations of the animal to the shell in. such a species as 
P. Knightii can only be inferred by comparison with other 
species in which the internal plates are less developed, and with 
other genera, such as Cyrtia and Camarophoria. In Fig. 179, 
the small central chamber {v) must have been occupied by the 
digestive organs, the large lateral spaces {d s) by the spiral 
arms ; it is doubtful whether any muscles were attached to these 
plates ; in Porambonites the adductor impression is situated 
beyond the point to which the dental plates converge, and in 
Camarophoria the muscular impressions occupy the same position 
as in Rhynchonella. 

Atrypa, Dalman. 

Synonyms, Cleiothyris, Phillips. Spirigerina, D'Orbigny.* 
Hipparionyx, Yanuxem. 

Type, A. reticularis, PL XY., Fig. 21. Figs. 180, 181. 




Fiff. 180. Dorsal valve. 



Fig. 181, Ventral valve ; interiors. 



p, hinge-plate; a, impressions of adductor muscle ; c, cardinal muscle ; p, pedicle 
muscle ; o, ovarian sinus ; d, deltidium. 

Shell impunctate ; oval, usually plaited and ornamented with 
squamose lines of growth ; dorsal valve gibbose ; ventral 
depressed in front ; beak small, often closely incurved ; foramen 
round, sometimes completed by a deltidium, often concealed ; 
dorsal valve with a divided hinge-plate, supporting two broad 
spirally coiled lamellae ; spires vertical, closely appressed, and 

* The term Atrypa, {a, without, trupa, foramen) is objectionable, like all Dalman's 
names ; but M. D'Orbigny has made no improvement by proposing Spirigerina, in 
addition to Spirifera, Spii-igera, and Spirifezina 



BKACHIOPODA. 



379 



directed towards the centre of tlie valve ; teeth, and impressions 
like Rhynclionella. 

The shells of this genns differ from Rhynchonella chiefly in 
the calcification of the oral supports, a character of uncertain 
value. 

Fossil, 21 species. Lower Silurian — Trias. America (Wel- 
lington Channel ! Falkland Islands), Europe, Thibet. 

Anoplotheca lamellosa, F. Sandberger, 1856, Devonian, Ehine, 
is a species of Atryjoa. 

Family IY. — Orthid^.* 

SheU transversely oblong, depressed, rarely foraminated ; 
hinge -line wide and straight ; beaks inconspicuous ; valves 
plano-convex, or concavo-convex, each with a hinge-area (h) 
notched in the centre ; ventral valve with prominent teeth {t) ; 
muscular impressions occupying a saucer-shaped cavity with a 
raised margin ; adductor (a) central ; cardinal and pedicle 
impressions (r) conjoined, lateral, fan-like ; dorsal valve with a 
tooth-like cardinal process between two curved brachial pro- 
cesses (c) ; adductor impression (a) quadruple ; vascular impres- 
sions consisting of six principal trunks in the dorsal valve, two 
in the ventral, the external branches turned outwards and back- 
wards inclosing wide ovarian spaces (o). Indications have been 





Dorsal valve. t Ventral valve. 

Fig. 182. Orthis striatula, Devonian, Eifel. 

observed, in several genera, of horizontally- coiled spiral arms ; 
the space between the valves is often very small. The shell- 
structure is punctate, except in a few instances, where the 
original texture is probably obliterated. 

* The names of the families are formed from those of the typical genera, by sub 
stituting ides for the last syllable of the genitive case, 

t From a specimen presented by M. De Koninck to the British Museum ; internal 
casts of this fossil were called hysferolites by old authors. 



380 MANUAL OF THE MOLLUSCA. 

Orthis, Dalman. 

Etymology , ortJios, straight. 
Tijpe, 0. rustica, PI. XY., Fig. 23. 

Synonyms, Dicoelosia (biloba), King. PlatystropLia (biforata), 
King. Gonambonites (inflexa), Pander. Ortbambonites (calli- 
granima), Pander. 

Shell transversely oblong, radiately striated or plaited, bi- 
convex, binge-line narrower tban the sbell, cardinal process 
simple, brachial processes tooth-like, prominent and carved. 

i^'ossi/, 154 species. Lower Silurian — Carb. Arctic America, 
Uni%d States, South America, Falkland Islands, Europe, 
Thibet. 

? Sub-genera. Orthisina, D'Orbigny. 0. anomala, Schl. 
Fig. 183. Synonyms, Pronites (ascendens) and Hemipronites, 

Pander. Shell impunctate ? widest at 
the hinge-line ; cardinal notch closed, 
byssal notch [fissure] covered by a 
convex pseudo-deltidium, sometimes 
perforated by a small round foramen. 
Fossil, Lower Silurian, Europe. 

0. pelargonatus (Streptorhynchus, 

King), from the Magnesian limestone. 

Fig. 183. Orthisina. q^ senilis, Carb. limestone, and some 

Devonian species, have the beak twisted, as if it had been 

attached ; there is no foramen. 

STROPHOMEisrA, Blainville.* 

Etymology, strophos, bent, mene, crescent 

Examples, S. rhomboidalis, PL XY., Fig. 24. (==Productus 
■depressus, Sby.) 

Synonyms, Lepteena (rugosa), Dalman. Leptagonia, M'Coy. 
Enteletes, Fischer. 

Shell semicircular, widest at the hinge-line, concavo-convex, 
depressed, radiately striated ; area double ; ventral valve with 
an angular notch, progressively covered by a convex pseudo- . 
deltidium ; umbo depressed, rarely (?) perforated, in young 
shells, by a minute foramen (Fig. 184, e) ; muscular depressions 
4, central pair narrow, formed by the adductor ; external pair 
(?n) fan-like, left by the cardinal and pedicle muscles ; dorsal 

* The name Strophome7ia (nigosa) was originally given by Rafinesque to some un- 
known or imaginary fossil; it has, however, been adopted both in America and 
Europe for the group typified by S. alternata and planuinbona. 




BEACHIOFODA. 



381 



valve "witli a bi-lobed cardinal process, between tbe dental 
sockets, and four depressions for the adductor muscles. 




Ventral valve. 



Dorsal valve. 




Fig. 184. 

Interior of S. rhomboidahs, var, analoga, Carb. limestone (after King). 
e, foramen ; t, teeth ; o, ovarian spaces ; b, brachial pits ? 

There are no apparent brachial processes in the dorsal valve 
of Strophomena, and it is possible that the spiral arms may have 
been supported at some point near the centre of the shell (&) as 
in Frodudus ; S. rhomboidalis occasionally exhibits traces of 
spiral arms, in the ventral valve. 
8. latissima, Bouch., has plain 
areas, like Oalceola. 

The valves of the Strophomenas 
are nearly flat until they approach 
their full growth, they then bend 
abruptly to one side ; the dorsal 
valve becomes concave in >S^. altei-- 
nata and rhomhoidalis, whilst in 
S. planumhona and euglypha it 
becomes convex; these distinc- 
tions are not even sub-generic. 

Fossil, 129 species. 
Europe, Thibet. 

S. demissa, Conr. (Stropheodonta, Hall), 8. Dutertrii, and 
several other species have a denticulated hinge-line. 

Sub-genera ? Leptoena (part), Dalman. L. transversalis, 
Pig. 185. (Plectambonites, Pander.) Yalves regularly curved; 
dorsal concave, thickened, muscular impressions elongated. 
Fossil, 41 species. Lower Silurian — Lias. North America and 
Europe. The lias Leptcenas resemble Thecidia internally ; they 
are free shells, with sometimes a minute foramen at the apex of 
the triangular deltidium ; L. liassina, PL XY., Fig. 25. 

Koninckia, Suess. Producta Leonhardi, Wissm. (P. alpina, 
Schl.), Pig. 186. Trias, St. Cassian. >S/ie/^ orbicular, concavo- 
convex, smooth ; valves articulated ? closely appressed ; ventral 
valve convex, dorsal concave ; beak incurved, no hinge-area 



Fig. 185. Leptana, |-. 
A, hinge-areas ; v, ventral ; b, interior 
of dorsal valve. 

Lower Silurian— Carb. ISTorth America, 



382 



MANUAL OF THE MOLLUSC A. 



nor foramen ? interior of each valve furrowed by two spiral lines 
of four volutions, directed inwards, and crossing the vascular 
impressions; umbo with three diverging ridges. The small 




Fig. 186. Produetics? Leonhardi, \.* 

spiral cavities, once occupied by the arms, and now filled with 
spar, may be seen in specimens with both valves, by holding 
them to the light. M. Suess, of Vienna, states that he has found 
traces of very slender spiral lamellae occupying the furrows. This 
curious little shell most resembles the Triassic LeptcEna dubia 
(Productus;, Miinster {=Cra7iia MurcMsoni, Klipst!). 

Davidsonia, Bouchard. 

Dedicated to the author of the Monograph of British Fossil 
Brachiopoda. 

Tyj)e, D. YerneuiH, Bouchard. Fig. 187. Devonian, Eifel. 




Dorsal valve. 



Fig. 187. 



Ventral valve.-|- 



Shell solid, attached by outer surface of the ventral valve to 
rocks, shells, and corals ; valves plain, articulated ; ventral 
valve with a wide area (h) ; foramen angular, covered by a 
convex deltidium (d) ; disk occupied by two conical elevations, 
obscurely grooved by a spiral furrow of 5-6 volutions ; dorsal 
valve with two shallow lateral cavities ; vascular impressions 
consisting of two principal sub-marginal trunks, in each valve, 
* A, translucent specimen ; B, interior of dorsal valve. 



BRACHIOPODA. 



383 



with diverging "brandies; cardinal and adductor impressions 
distinct. The furrowed cones undoubtedly indicate the existence 
of spiral arms, similar to those of Atrypa (Fig. 180), but desti- 
tute of calcified supports. The upper valve sometimes exhibits 
markings derived from the surface on which the shell has grown. 
The mantle-lobes seem to have continued depositing shell 
until the internal cavity was reduced to the smallest possible 
limit. 

Fossil, 3 species. Devonian — Trias. 




Dorsal valve 



Fig. 188. 



Ventral valve. 



Oalceola, Lamarck. 

Etymology, calceola, a slipper. 

Type, C. sandalina, PI. XV., Fig. 26. Fig. 188. 

Shell thick, triangular ; valves plain, not articulated ; ventral 
valve pyramidal ; area large, flat, triangular, with an obscure 
central line ; hinge-line straight, crenulated, dorsal valve flat, 
semicircular, with a narrow area {h), a small cardinal process 
(J), and two lateral groups of small apophysary (?) ridges {b) ; 
internal surface punctate-striate. 

Fossil, Devonian, Eifel, Britain. 

The supposed Carboniferous species {Rypodema, D.K.) is, per- 
haps, related to Fileopsis. Calceola is shaped like Cyrtia, and 
its hinge-area resembles that of some Strophomenas. 



Family V. — PEODtrcTiDJE. 

Shell concavo-convex, with a straight hinge-line ; valves 
rarely articulated by teeth ; closely appressed, furnished with 
tubular spines ; ventral valve convex ; dorsal concave ; internal 
surface dotted with conspicuous, funnel-shaped punctures; 
dorsal valve with a prominent cardinal process ; brachial pro- 
cesses (?) sub -central ; vascular markings lateral, broad, and 
simple ; adductor impressions dendritic, separated by a narrow 
central ridge ; ventral valve with a slightly notched hinge -Una ; 



nR4 



MANUAL OF THE MOLLUSCA. 



adductor scar central, near tlie umbo ; cardinal impressions 
lateral, striated. 




Pig. 189. Productus giganteus, J Carb. limestone. 
A, interior of dorsal valve ; B, interior of ventral valve, with tlie 'umbo removed; 
C, ideal section of both valves ; D, hinge-line of A ; j, cardir.al process ; a, adductor* 
r, cardinal muscles; b, oral processes?; s, hollows occupied by the spiral arms; v, 
vascular impressions ; A, hinge-area. 

Peoductus, Sowerby. 

Types, P. giganteus, Martin. z=Anomia produda, Martin. 

Examples, P. horridus, PI. XV., Pig. 27. P. proboscideus, 
PI. XV., Pig. 28. 

Shell free, auriculate, beak large and rounded ; spines scat- 
tered ; hinge-area in each yalve linear, indistinct ; no hinge- 
teeth ; cardinal process lobed, striated ; yascular impressions 
simple, curved ; ventral valve deep, with two rounded or sub- 
spiral cavities in front. These shells may have been attached 
by a pedicle when young, the impressions of the pedicle-muscle 
blending with those of the hinge-muscles (c) in the ventral 
valve. A few species appear to have been permanently fixed. 
P. striatus is irregular in its growth, elongated and tapering 
towards the beak, and occurs in numbers packed closely together. 
P. prohosddeus seems to have lived habitually in cavities, or 
half-buried in mud, as suggested by M. D'Orbigny; its ventral 
valve is prolonged several inches beyond the other, and has its 



BEACHIOPODA. 



885 



edges rolled together and uiiited, forming a large permanently- 
open tube for the brachial ciirrents. The large spines are most 
usually situated on the ears of the ventral valve, and may have 
served to moor the shell ; being tubular they were permanently- 
susceptible of growth and repair. Although edentulous, the 
dorsal valve must have turned on its long hinge-line with as 
much precision as in those genera which are regularly articulated 
by teeth. 

Fossil, 81 species. Devonian — Permian. North and South 
America, Europe, Spitzbergen, Thibet, Australia. 




Exterior. 



Fig. 190. 



Interior. 



Suh-genus. Aulosteges,'^Q\m.QTSQn. A. Wangenheimii, Vern., 
Pig. 190. Permian, Eusssia; Oarb. Shell like Producta; 
ventral valve with a large flat triangular hinge-area {h), with a 
narrow convex pseudo-deltidium {d) in the centre ; beak a little 
distorted, as if attached when young ; dorsal valve slightly- 
convex near the umbo ; interior as in Productus (longi-spinus). 



Strophalosia, King. 

Examjole, S. Cancrini, De Yern., Pig. 
191. 

Synonym, Orthothrix, Geinitz. 

Skell attached by the umbo of the 
ventral valve ; sub -quadrate ; covered 
with long slender spines ; valves arti- 
culated, dorsal moderately concave, 
ventral convex, each with a small area ; 
fissure covered; vascular impressions 
conjoined, reniform. 

Fossil, 8 species. Devonian — Carb. 
Europe, Himalaya (Gerard). 




Fig. 191. )S. Cancrini. 



386 



MANUAL OF THE MOLLUSCA. 



Chonetes, Eisclier. 

Example, 0. striateUa, PI. XV., Fig. 29. 

Etymology, chone, a cup. 

Shell transversely oblong, with a wide and straight hinge- line ; 
area double; valves radiately striated, articulated; hinge-margin 
of ventral valve with a series of tubular spines; fissure covered; 
interior punctate -striate ; vascular impressions {v) very small. 
(Davidson.) 

Fossil, 47 species. Silurian — Carboniferous. Europe, North 
America, Falkland Islands. 




Dorsal valve. 



Fig. 192. 



Ventral valve.* 



Family YI. — Chaniad^. 

Shell orbicular, calcareous, hinge-less ; attached by the umbo, 
or whole breadth of the ventral valve, rarely free ; dorsal valve 
limpet-like ; interior of each valve with a broad granulated 
border ; disk with four large muscular impressions, and digitated 
vascular impressions ; structure punctate. 

Animal with free spiral arms, directed towards the concavity 
of the dorsal valve, and supported by a nose-like prominence in 
the middle of the lower valve ; mantle extending to the edges 



of the valves, 
(Fig. 195.) 



and closely adhering; its margins plain. 



Cbania, Eetzius. 



Etymology, Jcraneia, capitate. 

Type, Anomia craniolaris, L. 

Examples, 0. Ignabergensis, PI. XY., Fig. 30. C. anomala, 
Figs. 193—195. 

Synonyms, Criopus, Poli. Orbicula (anomala), Cuvier, 
_=0. Norvegica, Lam. 

* Interiors of two sp. of Ckonetes, from Nehou and the Eifel, after Davidson : 0, 
adductor ; c, cardinals. 



BRACHIOPODA. 



387 



Shell STdodth. or radiately striated ; umbo of dorsal valve sub- 
central ; of ventral valve sub-central, marginal, or prominent 
and cap-like, with, an obscure triangular area traversed by a 
central line. 

The large muscular impressions of the attached valve are 




Fig. 193. Ventral valve. Fig. 194. Dorsal valve. 

Crania anomala, Muller. ^ Zetland. 
f7, anterior adductors; a', posterior adductors; c, posterior adjustors ; c\ cardinal 
ruuscle ; r, o, central and external adjustors. 



sometimes convex, in other species deeply excavated ; those of 
the upper valve are usually convex, but in C. Parisiensis the 
anterior (central) pair are developed as prominent diverging 
apophyses. In G. tripartita, Miinster, the nasal process divides 
the fixed valve into three cells.* 

G. Ignahergensis is equivalve, and either quite free or very 
slightly attached. 0. anomala is gregarious on rocks and stones 
in deep water, both in the North Sea and Mediterranean (40 — 90 
fathoms, living; 150 fathoms, dead; Forbes); the animal is 
orange-coloured, and its labial arms are thick, fringed with 
cirri, and disposed in a few horizontal gyrations (Fig. 195). 

Distribution, 5 species. Spitzbergen, Britain, Mediterranean, 
India, New South "Wales. — 150 fathoms. 

Fossil, 37 species. Lower Silurian — . Europe 

C. antiquissima, Eichw. (Pseudo-crania, M'Coy), is free, and 
has the internal border of the valves smooth ; the branchial 
impressions blend in front. Spondylohohis craniolaris, M'Coy, 
is a small and obscure fossil, from the Lower Silurian shale of 
Builth. The upper valve appears to have been like Crania, the 
lower to have had a small grooved beak, with blunt, tooth-like 
processes at the hinge-line. 

* M. Quenstedt has placed the Oolitic Cranias in Siphonaria ! 

s2 



388 



manual of the mollusca. 
Family YII. — Discinid^. 



Shell attaclied by a pedicle, passing tlirougli a foramen in tho 
ventral valve ; valves not articulated ; minutely punctate. 





Fig. 195. Crania.* 



Fig. 196. Discina.\ 



Animal with a Mglily vascular mantle, fringed with long 
horny setae ; oral arms curved backwards, returning upon them- 
selves, and ending in small spires directed downwards, towards 
the ventral valve. 



DisclNA, Lamarck. 

Syno'nyms, Orbicula, Sby. (not CuvierJ). Orbiculoidea 
(elliptica), D'Orbigny. Schizotreta, Kutorga. 

Types, D. lamellosa, PL XV., Fig. 31. (=:D. ostreoides, 
Lamarck.) 

Shell orbicular, horny ; upper valve limpet-like, smooth or 
concentrically lamellose, apex behind the centre ; lower valve 
flat or conical, with a sunk and j)erforated disk on the posterior 
side ; interior polished ; lower valve with a central prominence 
in front of the foramen. 

Animal transparent ; mantle lobes distinct all round ; labial 
folds united, not extensile, ; alimentary canal simple, bent upon 
itself ventrally, and terminating between the mantle-lobes on 
the right side. There are four distinct adductor muscles as in 

* Dorsal valve, with the animal, seen by removing the mantle. 

+ The animal as seen on the removal of part of tlie lower mantle-lobe ; the extremities 
of the labial arms are displaced forwards, in order to show their spiral terminations : 
V is the expanded surface of the pedicle ; the mouth is concealed by the overhanging 
cirri. The mantle-fringe is not represented. 

X The Orbicula of Cuvier was the Patella anomala, Miill (= Crania), as pointed out 
by Dr. Fleming, in the " History of British Animals," 1828.. 



BHACHIOPODA. 



389 



Crania; and three pair of adjuster muscles for keeping the 
valves opposed to each other. Some of these are probably 
inserted in the pedicle. The oral cirri are extremely tender and 
flexible, contrasting with th^ stiflf and brittle setse of the mantle, 




Dorsal. Fig. 198. Ventral lobe. 

Discina lamellosa, Brod, ^ 
w, umbo ; /, foramen ; d, disk ; a, anterior adductors ; a', posterior adductors ; 
e, c', central and posterior adjustors ; r, external adjusters. The martle-fringe is not 
represented in Fig. 198. 

which are themselves setose like the bristles of certain annelides 
{e.g the sea-mouse, Aphrodite). The relation of the animal to 
the perforate and imperforate valves is shown to be the same as 
in Terehratida, by the labial fringe ; but the only process which 
can possihly have afforded support to the oral arms is developed 
from the centre of the ventral valve, as in Crania. Baron 
Eyckholt has represented a Devonian fossil from Belgium, with 
a fringed border; but if this shell is the Crania obsoleta of 
Groldfuss, the fringe must belong to the shell, and not to the 
mantle. 

Distribution, 10 species. West Africa, Malacca, Peru, and 
Panama. 

Fossil, 64 species. Silurian-r— . Europe, United States, 
Falkland Islands. 

In some species the valves are equally convex, and the 
foramen occupies the end of a narrow groove. 

Sub-genus. Trematis, Sharpe. (=Orbicella, D'Orbigny.) 
T. terminalis, Emmons. Yalves convex, superficially punctate; 
dorsal valve with a thickened hinge-margin (and three diverg- 
ing plates, indicated on casts. — Sharpe). Fossil, 14 species, 
Lower and Upper Silurian. North America and Europe. 



390 



MAISTJAL OF THE MOL-LUSCA, 



SlPHONOTRETA, Yerneuil. 

JEtymoJogy , sipJion, a tube, tretos, perforated. 

Types, S. unguiculata, Eicli-w., Figs. 199, 201. S. verrucosa, 
Pig. 200. 

SheU oval, bi-convex, slightly beaked, conspicuously punctate, 
or spiny ; beak perforated by a tubular foramen ; hinge-margins 




fig. 199. 



Fig. 200. Exterior. 



Fig. 201. Interior. 



thickened ; ventral valve with four close adductor scars sur- 
rounding the foramen. The spines are tubular, and open into 
the interior of the shell by prominent orifices. (Carpenter.) 
S. anglica, Morris, has moniliform spines. 

Fossil, 9 species. Lower and Upper Silurian. Britain, 
Bohemia, Russia. 

? Acrotreta (sub-conica), Kutorga. 3 species. Lower Silurian, 
Russia. Shaped like Cyrtia, with an apical foramen ; no 



hinge. 



Family VIII. — Lustgulid^^. 



Shell oblong or orbicular, sub -equi valve, attached by a pedicle 
passing out between the valves ; texture horny, minutely 
tubular. 

Animal fwith a highly vascular mantle, fringed with horny 
setse ; oral arms thick, fleshy, spiral, the spires directed inwards, 
towards each other. 

LnsTGULA, Bruguiere. 

Etymology, lingula, a little tongue. 

Type, L. anatina, PI. XY., Fig. 32. 

Shell oblong, compressed, slightly gaping at each end, trun- 
cated in front, rather pointed at the umbones ; dorsal valve 
rather shorter, witlji a thickened hinge-margin, and a raised 
ceiitral ridge inside. 



BEACHIOrODA. 



391 



Animal witli the mantle-lobes firmly adhering to the shell, 
and united to the epidermis, their margins distinct, and fringed 
all round ; branchial veins giving off numerous free, elongated, 
narrow loops from their inner surfaces ; visceral cavity occupy- 




Fig. 202. Dorsal.* Fig. 203. Ventral. Fig. 204. Ventral. 

Lingula anatina. Lam. (original). Syn. Patella unguis, L. (part.) 
a a, anterior adductors ; a', posterior adductor; p ^, external adjusters ; p'p', central 
adjusters ; r r, anterior retractors (the anterior occlusors of Hancock) ; r'r'r', posterior 
adjusters ; c, capsule of pedicle ; n n, visceral sheath ; o, oesophagus ; s, stomacJ* . 
/, liver ; i, intestine ; v, vent ; b, branchial vessels ; vi', mantle margin ; to, inner lamina 
of mantle margin retracted, showing bases oi setae ; *, S-'tae. 

ing the posterior half of the shell, and surrounded by a strong 
muscular sheath ; pedicle elongated, thick ; stomach long and 
straight, sustained by inflections of the visceral sheath ; intes- 
tine convoluted dorsally, terminating between the mantle-lobes 
on the right side, oral arms disposed in about six close whorls, 
their cavities opening into the prolongation of the visceral 
shea.th in front of the adductors. 

Observations on the living lingula are much wanted; the 
oral arms probably extended as far as the margins of the shell ; 
and the pedicle, which is often nine inches long in preserved 
specimens, is doubtless much longer, and contractile when 

* In Fig. 202 a small portion of the liver and visceral sheath have been removed, to 
show the course of the stomach and intestine. In some specimens the whole of the 
vis. era, except a portion of the liver, are concealed by the ovaries. In Fig. 204 the 
front half of the ventral mantle-lobe is raised, to show the spiral arms ; the black spot 
in the centre is the mouth, with its upper and lower lips, one fringed, Uie other plain. 
The manile-fringe has ueen omitted in Figs. 202, 204. 



392 



MANUAL OF THE MOLLUSC A. 



alive. The shell is horny and flexible, and always of a greenish 
colour. 

Distribution, 16 species. India, Philippines, Moluccas, Aus- 
tralia, Feejees, Sandwich Islands, West America. 

Fossil, 91 species. Lower Silurian — . North America, Europe, 
Thibet. 

Linguloe existed in the British seas as late as the period of the 
Coralline Crag. The recent species have been found at small 
depths, and even at low water half buried in sand. L Davisii, 
Lower Silurian, Tremadoc, has a pedicle -groove like Oholus, 
Pig. 205. (Salter.) 




Fig. 205. Ventral valve. Fig. 206. Dorsal valve. 

Obolus Davidsoni. (Salter.) "Wenlock limestone, Dudley. 
A, posterior adductors ; B, adjustors ; C, anterior adductors. 

The pedicle-scar in the centre of Fig. 168 has no letter. 



Obolus, Eichwald. 

Synonyms, TJngula, Pander ; Aulonotreta, Kutorga. 

Etymology , oholus, a small Greek coin. 

Type, 0. Apollinis, Eichw. 

Shell orbicular, calcareo-corneous, depressed, sub-equivalve, 
smooth ; hinge-margin thickened inside, and slightly grooved 
in the ventral valve ; posterior adductor impressions separate ; 
anterior pair siib-central; impressions of adjustors lateral. 
Fig. 205, 206. (After Davidson.) 

Fossil, 8 species. Lower and Upper Silurian. Sweden, 
Eussia, England, United States. 



• CONCHIFEUA. 393 

CHAPTEE IV. 

CLASS Y. COKCHIFEEA, Lamauck. 

{LamelU- hrancMafa^ Blainville . ) 

The bivalve shell-fish, or Concliifera, are familiar to every 
one, under the form of oysters, scallops, mussels, and cockles.* 
They come next to the univalves [gasteropoda) in variety and 
importance, and though less numerous specifically, are far more 
abundant individually. f The bivalves are all aquatic, and 
excepting a few widely-dispersed and prolific genera, are all 
inhabitants of the sea ; they are found on every coast, and in 
every climate, ranging from low- water mark to a depth of more 
than 200 fathoms. 

In their native element the Oyster and Scallop lie on one side, 
and the lower valve is deeper and more capacious than the 
upper ; in these the foot is wanting, of else small, and not used 
for locomotion. Most other bivalves live in an erect position, 
resting on the edges of their shells, which are of equal size. 
Those which move about much, like the river -mussel, maintain 
themselves nearly horizontally, X and their keel- shaped foot is 
adapted for ploughing through sand or mud. The position of 
those bivalves which live half -buried in river-beds or at the 
bottom of the sea, is often indicated by the darker colour of the 
part exposed ; or by deposits of tufa, or the growth of seaweed 
on the projecting ends of the valves. 

In Nucula and some others the foot is deeply cleft, and 
capable of expanding into a disk, like that on which the snails 
glide ; whilst in the mussel, pearl-oyster, and others which 
habitually spin a hyssus, the foot is finger-like and grooved. 

The burrowing species have a strong and stout foot with 
which they bore vertically into the sea-bed, often to a depth 
far exceeding the length of their valves ; these never volun- 
tarily quit their abodes, and often become buried and fossilised 
in them. They most usually burrow in soft ground, but also 
in'coarse gravel, and firm sands and clays ; one small modiola 
makes its hole in the cellulose tunic of Ascidians, and another 
in floating blubber. 

* They are the Dithyra of Aristotle and Swainson, and constitute the second or 
sub-typiual group in the quinary system. 

t It has been stated that the predatory mollusca are more numerous than the 
vegetable-feeders ; but it is not so with the individuals constituting the species. 

X This is the position in which they are always figured in English books, being bes6 
suited for the comparison of one shell with another. 

s3 



394 MANUAL OF TaE MOlLtlSCA. 

The boring s"hell>'fisli have been distinguislied from the mere 
burrowers, perhaps without sufficient reason, for they are found 
in substances of every degree of hardness, froUi soft mud to 
compact limestone, and the method employed is probably the 
same.* 

The means by which bivalves perforate stone and timber has 
been the subject of much inquiry, both on account of its phy- 
siological interest, and the desire to obtain some remedy for 
the injuries done to ships, and piers, and breakwaters. The 
ship-v/orm {teredo) and some allied genera, perforate timber 
only ; whilst the pjiolas bores into a variety of materials, such 
as chalk, shale, clay, soft sandstone and sandy marl, and 
decomposing gneiss ;t it has also been found boring in the peat 
of submarine forests, in wax, and in amber 4 It is obvious 
that these substances can only be perforated alike by mechanical 
means ; either by the foot or by the valves, or both together, 
as in "the burrowing shellfish. The pJiolas shell is rough, like a 
file, and sufficiently hard to abrade limestone ; and the animal 
is able to turn from side to side, or even quite round in its cell, 
the interior of which is often annulated with furrows made by 
the spines on the front of the valves. The foot of the j3/;o/as is 
very large, filHng the great anterior opening of the valves ; 
that of the ship-worm is smaller, but surrounded with a thick 
collar, formed by the edges of the mantle, and both are armed 
with a strong epithelium. The foot appears to be a more 
efficient instrument than the shell in one respect, inasmuch as 
its surface may be renewed as fast as it is worn awav.§ (Han- 
cock.) 

The mechanical explanation becomes more difficult in the 
case of another set of shells, Hthodomus, gastrochcena^ saxicava, 
and ungulina, which bore only into calcareous rocks, and attack 
the hardest marble, and still harder shells. (Fig. 25, p. 34). 
In these the valves can render no assistance, as they are smooth, 
and covered with epidermis ; neither does the foot help, being 
small and finger-like, and not applied to the end of the burrow. 
Their power of movement also is extremely limited, their cells 
not being cylindrical, whilst one of them, saxicava, is fixed in 

* See the admirable memoir by Mr. Albany Hancock, in the An. Nat. Hist, for " 
October, 1848. 

t There is a specimen from the coast of France, in the Brit. Musemn. 

X Highgate resin, in the cabinet of Mr. Bowerbank. 

^ The final polish to some steel goods is said to be given by the hands of work- 
women. In Carlisle Castle they point to the niiie impress'on of a hand on the 
dnngcon wall, as the work of Fergus M'lvor, in the two years of his solitary ira- 
jHrisonment. 



COKCHIFEEA. 395 

its crypt by a hyssus. These shell fish have been supposed to 
dissolve tiie rock by chemical means (Deshayes), or else to 
"wear it away with the thickened anterior margins of the 
mantle. (Hancock.)* 

The holes of the lithodomi often serve to shelter other animals 
after the death of the rightful owners ; species of Modiola, Area, 
Venericpis, and CoralUophaga, both recent and fossil, have been 
found in such situations, and mistaken for the real miners. t 

The boring shell-fish have been called " stone -eaters " 
[Uthophagi] and "wood-eaters" [xylophagi], and some of them 
at least are obliged to swallow the material produced by 
their operations, although they may derive no sustenance from 
it. The ship-worm is often filled with pulpy, impalpable 
sawdust, of the colour of the timber in which it worked. 
(Hancock.) Ko shell-fish deepens or enlarges its burrow after 
attaining the full growth usual to its species (p. 35). 

The bivalves live by filtering water through their gills. "| 
"Whatever particles the current brings, whether organic or 
inorganic, animal or vegetable, are collected on the surface 
of the breathing- organ and conveyed to the mouth. In this 
manner they help to remove the impurities of turbid water. § 
The mechanism by which this is efiected may be most conve- 

* All attempts to detect the preserce of an acid secretion have hitherto failed, as 
might be expected ; for the hypothesis of an acid solvent supposes only a very feeble 
but continuous action, such as in nature always works out the greatest results in the 
end. See Liebig's Organic Chemistry, and Dumas and Boussingault on the "Balance 
of Organic Nature." Intimately connected with this question are several other 
phenomena; the removal of portions of the interior of univalves, by the arimiil 
itself, as in the genera Conus, Auricula, and Nerita (Fig. 24, p. 32) ; the perforation of 
shells by the tongues of the carnivorous gasteropods, and the formation of holes in 
wood and limestone by limpets. Some facts in surgery also illustrate tliis subject, 
.(1) dead bone is removed when granulations grow into contact with it : (2) if a hole is 
bored in a bone, and an ivory peg driven into it, and covered up, so much of the peg as 
is embedded in the bone "S^ill be removed. (Paget.) The "absorption " of the fangs 
of milk-teeth, previous to shedding, is well known. In these cases the removal of the 
bone earth is eifected without the development of an acid, or other disturbance of the 
neutral condition of the circulating fluid. 

t Fossil univalves (trocki) occupying the burrows of a pholas, were discovered b5' 
Mr. Bensted in the Kentish-rag of Maidstone. See Mantell's Medals of Creation. 
M. Buvignier has found several Bpecies of Area fossilised in the burrows of 
Ht/iodovii. 

t It seems scarcely necessary to remark that the bivalves do not feed upon prey 
caught between their valves. Microscopists are well aware that sediment taken from 
the alimentary canal of bivalve shellfish contains the skeletons of animalcules and 
minute vegetable organisms, whose geometrical forms are remarkably varied and 
beautiful ; they have also been obtained (in greater abundance than ordinary) from 
mud filling the interior of fossil oyster-shells. 

§ When placed in water coloured with indigo, they will in a short time render it 
clear, by collecting the minute particles and condensing Jiem into a solid form. 



896 



MANITAL OF THE MOLLUSCA. 



niently examined in a bivalve with a closed mantle, like tlie 

great My a (Fig. 207), which 
lives in the mnd of tidal rivers, 
with only the ends of its long 
combined siphons exposed at the 
surface.* The siphons can be ex- 
tended twice the length of the 
shell, or drawn completely with- 
in it ; they are separated, in- 
ternally, by a thick muscular 
wall. The branchial siphon (s) 
has its orifice surrounded by 
a double fringe ; the exhalent 
siphon (s') has but a single row 
of tentacles ; these organs are 
very sensitive, and if rudely 
touched the orifices close and 
the siphon itseK is rapidly with- 
drawn. Whenunmolested, a cur- 
rent flows steadily into the orifice 
of the branchial siphon, whilst 
another current rises up from 
the exhalent tube. There is no 
other opening in the mantle ex- 
cept a small slit in front {jp) 
through which the foot is pro- 
truded. The body of the animal 
occupies the centre of the shell 
(5), and in front of it is the 
mouth (o) furnished with an 
upper and a lower lip, which are 
-f prolonged on each side into a 
pair of large membranous palpi 
[t). ThegiLls [g] are placed two 

on each side of the body, and 

ripr. 207. Mya arenaria. t j_i t t ^ ±t • 

are attached along their upper, 

or dorsal margins ; behind the body they are united to each other 

* Alder and Hancock on the branchial currents of Pholas and Mya. An. Nat. 
Hist., Nov. 1851. 

t Mya arenaria, L. (original, from specimens obtained at Southend, and commu- 
nicated by Miss Hume). The left valve and mantle lobe and half the siphons are re- 
moved, a, a', adductor muscles ; 6, body ; c, cloaca ;/, foot ; gr, branchiae ; A, heart; 
m, cut edge of the mantle ; o, mouth ; 5, s', siphons ; t, labial tentacles ; v, vent. The 
arrows indicate Ihe direction of the currents ; the four rows of dots at the base of the 
gills are the orifices of the branchial tubes, opening into the dorsal channels. 




COXCHIFEEA. 397 

and to tlie siplional partition. Eacli gill is composed of two 
laminee, divided internally into a series of parallel tnbes, indicated 
outside by transverse lines ; tliese tnbes open into longitudinal 
channels at tbe base of tbe gills, wbicb unite behind the posterior 
adductor muscle at the commencement of the exhalent siphon (c). 
Examined by the microscope, the gill laminee appear to be a 
network of blood-vessels whose pores opening into the gill -tubes, 
are fringed with vibratile cilia. These microscopic organs perform 
most important ofiELces ; they create the currents of water, arrest 
the floating particles, and mould them, mixed with the viscid 
secretion of the surface, into threads, in the furrows of the gill, 
and propel them along the grooved edge of its free margin, in 
the direction of the mouth ; they are then received between the 
palpi in the form of ravelled threads. (Alder and Hancock.) 

In My a, therefore (and in other burrowers), the cavity of the 
shell forms a closed branchial chamber, and the water which 
enters it by the respiratory siphon can only escape by passing 
through the gills into the dorsal channels, and so into the 
exhalent siphon. In the river-mussel the gills are not united 
to the body, but a slit is left by which water might pass into 
the dorsal channel, were it not for the close apposition of the 
parts under ordinary circumstances (Fig. 208 V), The gills of 
the oyster are united throughout, by their bases, to each other 
and to the mantle, completely separating the branchial cavity 
from the cloaca. In Pecten the gills and mantle are free, but 
the '-dorsal channels" still exist, and carry out the filtered water. 

In some genera the gills subserve a third purpose ; the 
oviducts open into the dorsal channels and the eggs are received 
into the gill-tubes and retained there until they are hatched. 
In the river-mussel the outer gills only receive the eggs, 
with which they are completely distended in the winter months 
(Eig. 208, 0, o). In Cyclas the inner gills form the marsupium, 
and only from 10 to 20 of the fry are found in them at one 
time ; these remain until they are nearly a quarter the length of 
the parent.* 

The valves of the Co7zcAt/era are bound together by an elastic 
ligament, and articulated by a hinge furnished with interlock- 
ing teeth. The shell is closed by powerful adductor muscles, 
but opens spontaneously by the action of the ligament, when the 
animal relaxes, and after it is dead. 

Each valve is a hollow cone, with the apex tui'ned more or 

* Some other particulars respecting the orgatiisation and development of bivalve 
shell-fish are given in Chapter I. For an account of their vascular system see Milne- 
Edwards, An. Sc. Nat. 1847, tom. viii. p. 77. 



308 



MAinJAL OP THE MOLLUSCA. 



less to one side ; the apex is the point from -whicli the growth 
of the valve commences, and is termed the beak, or umho (p. 29). 
I'he beaks {umhones) are near the hinge, because that side 
grows least rapidly, sometimes they are finite marginal ; bnt 
they always tend to become wider apart with age. The beaks 
are either straight, as in Peden; curved, as in Venus ; or spiral, 
as in Isocardia and Diceras. In the latter case each valve is 
like a spiral univalve, especially those with a large aperture 
and small spire, such as Concholepas ; it is the left valve which 
resembles the ordinary univalve, the right valve being a left- 
handed spiral like the reversed gasteroiDods. When one valve 
is spiral and the other flat, as in Cliama ammonia (Fig. 224), 




Fig. 20S. River-mussel. {Anodon cygneiis 9) * 

the resemblance to an operculated spiral univalve becomes very 
striking. 

The relation of the shell to the animal may be readily deter- 
mined, in most instances, by the direction of the umhones, and 
the position of the ligament. The umbones are turned towards 
the front, and the ligament is posterior ; both are situated on 
the back, or dorsal side of the shell. The length of a bivalve 
is measured from the anterior to the posterior side, its. breadth 
from the dorsal margin to the base, and its thickness from the 
centres of the closed valves. f 

The Conchifera are mostly equivalve, the right and left valves 

* The valves are forciblj' opened and the foot (/) contracted; a, anterior adductor- 
muscle, much stretched ; p, p, palpi ; g, inner gills ; o, o, outer gills distended with 
spawn ; b, b, & bristle passed through one of the dorsal channels. 

t Linnaeus and the naturalists of his school described the front of the shell as the 
back, the left valve as the right, and vice versa. lu those works which have been 
compiled from "original descriptions" (instead of specimens) sometimes one end, 
sometimes the other, is called anterior ; and the length of the shell is sometimes 
estimated in the direction of the length of the animal, but just as frequently in a line 
at right angles to it. 



1 



COlTCinFEBA. 



899 



being of tlie same size and shape, except in the Ostreidce and 
a few others. In Ostrea, Pandora, and Lyonsia, the right valve 
is smallest ; in Chamostrea and Corhida, the left ; whilst the 
Chamacece follow no rule in this respect. 
The bivalves are all more or less inequilctferal, the anterior 

Dorsal Margin. 



Pnaterior 
side. 




\ Anterior 
J;~ i^ side. 



Ventral margin or base. 

Tig. 209. Vnio pictontm, L. (original), with the right valve and mantle-lobe removed ; 
a, a, adductor muscles ; p, p, pedal muscles ; x, accessory pedal muscle ; u, lunbo ; 
I, ligament ; b, branchial orifice ; v, anal opening ; /, foot ; o, moutli ; t, palpi, 

being usually much shorter than the posterior side, Pedunculua 
is nearly equilateral, and in Glydmeris and Solemya the anterior 
is much longer than the posterior side. The front of the 
smaller Pectens is shown by the byssal notch ; but in the large 
scallops, oysters and Spondyli, the only indication of the posi- 
tion of the animal is afforded by the large internal muscular 
impression, which is on the posterior side. The ligament is 
sometimes between the umbones, but is never anterior to them. 
The siplional irnpression, inside the shell, is always posterior. 

Bivalves are said to be dose, when the valves fit accurately, 
and gaping, when they cannot be completely shut. In Gastro- 
chcBna (PI. XXIII., Fig. 15), the opening is anterior, and serves 
for the passage of the foot ; in Aiya it is posterior and siphon al ; 
in Solen and Olycimeris both ends are open. In Bysso-arca 
(PI. XYII., Pig. 13), there is a ventral opening formed by 
corresponding notches in the margin of the valves, which serves 
for the passage of the byssus ; in Pecten, Avicida, and Anomia 
(Fig. 211, s), the byssal notch (or sinus) is confined to the right 
valve. 

The surface of bivalve shells is often ornamented with ribs 
which radiate from the umbones to the margin, or with con- 
centric ridges, which coincide with the lines of growth. Some- 
times the sculpturing is oblique, or wavy ; in Tellina fahula 
it is confined to the right valve. In many species of Pholas, 



400 'MANUAL OP THE MOLLtTSCA. 

Teredo^ and Cardium, the surface is divided into two areas by 
a transverse furrow, or by a change in the direction of the ribs. 
The lunule (see Fig. 14, p. 20) is an oval space in. front of the 
beaks ; it is deeply impressed in Cardium retusum, L. Astarte 
excavata, and the^ genus Ojns. When a similar impression exists 
behind the beaks, it is termed the escutcheon.* 

The ligament of the Conchifera forms a substitute for the 
muscles by which the valves of the BracMopoda are opened. 
It consists of two parts, the ligament properly so called, and 
the cartilage ; they exist either combined or distinct, and some* 
times one is developed and not the other. The external ligament 
is a horny substance, similar to the epidermis which clothes the 
valves ; it is usually attached to ridges on the posterior hinge - 
margins, behind the umbones, and is consequently stretched 
by the closing of the valves. The ligament is large in the river- 
mussels, and small in the Mactras and Myas, which have £i 
large internal cartilage ; in Area and Fectunculus the ligament 
is spread over a flat, lozenge-shaped area, situated between the 
ambones, and furrowed with cartilage grooves. In Chama and 
Isocardia the ligament splits in front, and forms a spiral round 
each umbo. The Pholades have no ligament, but the anterior 
adductor is shifted to such a position on the hinge-margin that 
it acts as a hinge-muscle. (PI. XXIII., Fig. 13.) 

The internal ligament, or cartilage^ is lodged in furrows 
formed by the ligamental plates, or in pits along the hinge- 
line; in Mya and Nucida it is contained in a spoon-shaped 
process of one or both valves. It is composed of elastic fibres 
placed perpendicularly to the surfaces between which it is 
contained, and is slightly iridescent when broken ; it is com- 
pressed by the closing of the valves, and tends forcibly to open 
them as soon as the pressure of the muscles is removed. The 
name Amphidesma (double ligament) was given to certain 
bivalves, on the supposition that the separation of the cartilage 
from the ligament was peculiar to them. The cartilage-pit of 
many of the Anatinidce is furnished internally with a movable 
ossicle. 

The ligament is frequently preserved in fossil shells, such 
as the great Cyprinas and Carditas of the London Clay, the 
Unios of the Wealden and even in some lower Silurian bivalves. 

All bivalves are clothed with an epidermis {v. p. 33) which 
is organically connected with the margin of the mantle. It is 
developed to a remarkable extent in Solemya and Olycimeris 

* Onh' those technical terms which are used in a peculiar sense are here refen-ed to; 
foi the rest, any Dictionarj' may be consulted, especially Roberts's " Etj-mological 
Dictionarj' of Geology " published by Longman and Co. 



CONCHIFEEA. 



401 



(PI. XXII., Figs. 13, 17), and in My a it is continued oyer the 
siphons and closed mantle-lobes, making the shell appear 
internal. 

The interior of bivalves is inscribed with characters borrowed 
directly from the shell-fish, and affording a surer clue to its. 
affinities thai), those which the exterior presents. The structure 
of the hinge characterises both families and genera, whilst the 
condition of the respiratory and locomotive organs may be to 
some extent inferred from the muscular markings. 

The margin of the shell on which the ligament and teeth, 
are situated, is termed the hinge-line. It is very long and 
straight in Avicula and Area, very short in Vulsella, and curved 
in most genera. The locomotive bivalves have generally the 
strongest hinges, but the most perfect examples are presented 
by Area "and Spondylus. The central teeth, those immediately 
beneath the umbo, are called hinge (or cardinal) teeth ; those 
on each side are lateral teeth. Sometimes lateral teeth are 
developed, and not cardinal teeth [Alasmodon ; Kellia) : more 
frequently the hinge-teeth alone are present. In young shells 
the teeth are sharp and well-definied ; in aged specimens they 
are often thickened, or even obliterated by irregular growth 
[Hippojpodium) or the encroachment of the hinge-line [Fectun- 
culus). Many of the fixed and boring shells are edentulous* 

The muscidar impressions are those of the adductors, the foot 
and byssus, the siphons, and the mantle (see pp. 19, 20). 





Fig, 210. Left valve. {Pecfenv r.ius.) Eight valve. 

a, a, adductor; p, pedal impression; m, palial line; Z, ligamental margin; c, c, ctr- 

tilage ; e, e, anterior ears ; b, byssal sinus. 

The adductor impressions are usually simple, although the 

* The dentition of bivalve shells may be stated thus -.—cardinal teeth, 2.3 or | — 
meaning 2 in the right valve, 3 in the left; lateral teeth 1 — ], 2.-»2, or 1 anterior and 1 
posterior in the right valve, 2 anterior ar.d 2 posterior lat(ril teeth in the left valve. 



402 



MANTJAX or THE MOLLFSCA. 



muscles themselves may be composed of two elements,* as 
in Cytherea cMone (Fig. 14, p. 20) and the common oyster. 
The impression of the posterior adductor in Spondylus is double 
(PL XVI., Eig. 15). In Peden varius (Fig. 210, a a), large 
independent impressions are formed by the two portions of 
the adductor, and in the left valve there is a third impression 
(p) produced by the foot, which in the byssiferous pectens is a 
simple conical muscle with a broad base. 

In the left valve of Anomia there are four distinct muscular 
impressions (Fig. 213). Of these, the small posterior spot alone 
is produced by the adductor^ and corresponds with the solitary 




Fio;. 211. Eio-ht valve. 



Fig. 212. 



Fig. 213. Left valve,t 



impression in the right valve. The adductor itself (Fig. 212, a) 
is double. The large central impression [p) is produced by the 
muscle of the plug (the equivalent of the hyssal muscle in Pinna 
and Modiola). The small impression within the umbo [u) and 
the third impression in the disc {p') (wanting in Placunomia) are 
caused by the retractors of the foot. 

The term monomyary, employed by Lamarck to distiriguish 
the bivalves with one adductor, applies only to the Ostreidce, 
part of the Avicididcs, and to the genera Tridacna and Miilleria. 

The dimyary bivalves have a second adductor, near the anterior 
margin, which is small in Mytilus (Fig. 30), but large in Pinna, 
The retractor muscles of the foot (already alluded to at p. 20) 
have their fixed points near those of the adductors ; the anterior 
pair are attached within the umbones (Fig. 214, u u), or nearer 
the adductor, as in Astarte and Unio (Fig. 209). The posterior 
pair (p'p) are often close to the adductor, and leave no separate 



* Compare the sheU of modiola, PI. XVII., Fig. 5, with the woodcnt, Fig. 214. 

T Fig. 211. Eight valve of Anomia ephippium, L. Z, ligamental process ; s, sinus. 
Fig i2i3. Left valve; I, ligament pit. Fig. 212. Muscula;- system, from a dravring 
corPTnujiicated by A. Hancock, Esq. /, the foot ; pi, the plug. The muscle p is 
genera J J' described as a portion of the adductor ; but it is certain, from a comparison 
of 11 lis si 1 ell with Coro/jV? and P/flrana, that <i' represents the entire adductor, andp 
the byssal muscle. 



COIS'CHIFERA . 



403 



impression. Tlie Uniomdce have two additional retractors of the 
foot, attaclied laterally behind the anterior adductors ; in Lcda, 
Solenella, and a few others, this lateral attachment forms a 
line extending from the anterior adductor backwards into the 
umbonal region of the shell. (See PI. XYII., Eigs. 21, 22.) 

In those shellfish like Pinna and the mussel, which are ]3er- 
manently moored by a strong hyssus, the foot (/) serves only to 
mould and fix the threads of which it is formed. The fibres 
of the foot-muscles pass chiefly to the byssus (5), and besides 
these two additional muscles [jp Jp) are developed. In Pinna y 




Fig. 214. Muscles of Madiola. * 

Ilodiola, and Breissena the byssal muscles are equal to the great 
adductors in size. 

In a few rare instances the muscles are fixed to promi- 
nent apo2:)hyses. The falciform processes of Pholas and Teredo 
(PI. XXIII. , Figs. 19, 26) are developed for the attachment of 
the foot-muscle ; the posterior muscular ridge of Diceras and 
Cardilia resembles a lateral tooth, and in the extinct genus 
Radiolites both adductors were attached to large tooth-like pro- 
cesses of the opercular valve ; but, as a rule, the muscles deposit 

* Fig. 214. Muscular system of Modiola modiohis, L.. from a drawing communi- 
cated bj' A. Hanc' ck, Esq. aa, anterior, a'a\ posterior adductors ; uu and p'p', pedai 
muscles : vp, byssal muscles ; /, foot ; b, byssus ; m, pallial line. 



404 MANUAL OV THE MOLLUSC A. 

less sliell than the mantle, and their impressions deepen with 



The pallial line (Fig. 214, m) is produced by the muscular 
fibres of the mantle-margin; it is broken up into irregular 
spots in the monomyary bivalves, and in Saxicava and Fanopcea 
Norvegica. 

The siphoned impr£ssion, or pallial sinus (Fig. 14, p. 20), only 
exists in those shells which have retractile siphons ; its depth 
is an index to their length. The large combined siphons of 
My a (Fig. 207) are much longer than the shell ; and those of 
some Tellinidct three or four times its length, yet they are com- 
pletely retractile. The small siphons of Cydas and Dreissena 
cause no inflection of the pallial line. The form of the sinus 
is characteristic of genera and species. 

In the umbonal area (within the pallial line) there are some- 
times furrows produced by the viscera, which may be distin- 
guished from the muscular markings by absence of polish and 
outline, (See Lucina, PI. XIX., Fig. 6.) 

Fossil bivalves are of constant occurrence in all sedimentary 
rocks; they are somewhat rare in the older formations, but 
increase steadily in number and variety through the secondary 
and tertiary strata, and attain a maximum of development in 
existing seas. 

Some families, like the Cyprinidce and Lucinidce are more 
abundant fossil than recent ; whilst many genera, and one whole 
family (the Ilippuritidct), have become extinct. The determi-^ 
nation of the aflB.nities of fossil bivalves is often exceedingly 
difficult, owing to the conditions under which they occur. 
Sometimes they are found in pairs, filled up with hard stone ; 
and frequently as casts, or moulds of the interior, giving no 
trace of the hinge, and very obscure indications of the muscular 
markings. Casts of single valves are more instructive, as they 
afford impressions of the hinge.* 

Another difficulty arises from the frequent destruction of the 
nacreous or lamellar portion of the fossil bivalves, whilst the 
cellular layers remain. The Avicididce of the chalk have entirely 
lost their pearly interiors ; the Spondyli, CJiamas, and Badiolite^ 
are in the same condition, their inner layers are gone and no 
vacancy left, the whole interior being filled with chalk. As it 
is the inner layer alone which forms the hinge, and alone 
receives the impressions of the soft parts, the true characters of 

* These impressions may be conveniently nioulded ^\ith gufta-percha. M. Agassiz 
published a set of plaster-casts of the interiors of the genera of recent shells, which 
may be seen in the Brit. Museum. [Memoiresnr les ?nou!es des MoUusques, vivans ct 
fussiles, par L. Agassiz, Mem. Soc. i:c. Nut. Neuchatel, t.2.] 



COirCHIFEEA. 405 

'cke shells conld not be determined from sncli specimens. Our 
knowledge of the ex:tinct Radiolite is derived from natural 
moulds of the interior, formed before the dissolution of the 
inner layer of shell, or from specimens in which this layer is 
replaced by spar. 

The necessities of geologists have compelled them to pay very 
minute attention to the markings in the interior of shells, to 
their microscopic texture, and every other available source of 
comparison and distinction. It must not, however, be expected 
that the entire structure and affinities of molluscous animals 
can be predicated from the examination of an internal mould oT 
a morsel of shell, any more than that the form and habits of an 
extinct quadruped can be inferred from a solitary tooth or the 
fragment of a bone.* 

The systematic arrangement of the bivalves now employed is 
essentially that of Lamarck, modified, however, by many recent 
observations. The families follow each other according to rela- 
tionship, and not according to absolute rank; the Veyuridce are 
the highest organised, and from this culminating point the 
stream of affinities takes two courses, one towards the My as, 
the other in the direction of the oysters ; groups analogically 
related to the Tunicaries and Brachiopoda. 

SECTION A. AsiPHOKiDA. 
a. Pallial line simple : Integro-pallialia, 

Fam, 1. Ostreidse. t 4. Arcadse. 

2. Aviculidse. 5. Trigoniadse* 

3. Mytilidse. { 6, TJnionidse. 

SECTION B. SiPHONiD'A. 



7. Chamidse. 

8. Hippuritidse. 

9. Tridacnidse. 
10. Cardiadse. 



11, Lucinidse. 

12, Cycladidse* 

13, Cyprinidse. 



h. Pallial line simuded : Sinu-pallialia, 

14. Yeneridse. 

15. Mactridse. 

16. Tellinidse. 

17. Solenidse. 

The characters which have been most relied on for distin- 



18. Myacidse, 

19. Anatinidse. 

20. Gastrochsenidse. 

21. Pholadidae. 



* Eludes Critiques sur les Mollusqiies Fossiles.par L. Ar/assiz, Neuchatel, 1840. 



406 MANUAL OF THE MOLLUSCA. 

guisliiiig these groups and the genera of bivalves are the fol- 
lowing, stated nearly in the order of their value :— 

1. Extent to which the mantle-lobes are united. 

2. Number and position of muscular impressions. 

3. Presence or absence of sl pallial sinus. 

4. Form of the foot. 

5. Structure of the branchiae. 

6. Microscopic structure of the shell, {v. p. 31.) 

7. Position of the ligament, internal or external* 

8. Dentition of the hinge. 

9. Equality or inequality of the valves. 

10. Eegularity or irregularity of form. 

11. Habit; — free, burrowing or fixed. 

12. Medium of respiration, fresh or salt water* 

A few exceptions may be found, in which one or other of 
these characters does not possess its usual value.* Such in- 
stances serve to warn us against too implicit reliance on single 
characters. Groups, to be natural, must be based on the con- 
sideration of all these particulars — on ' ' the totality of the 
animal organisation." (Owen.) 

SECTIOlSr A. — ASIPHONIDA. 

Animal unprovided with respiratory siphons; mantle-lobes 
free, or united at only one point which divides the branchial 
from the exhalent chamber {cloaca) ; pallial impression simple. 

Shell usually pearly or sub -nacreous inside; cellular ex- 
ternally ; pallial line simple or obsolete. 

* 1. Cardita and Crassatella (Fato^ 13) have the mantle more open, whilst in Iridina 
{%), and especially in Dreissena (3) it is mol-e closed than in the most nearly allied 
genera. 

2. Midler m (6) and Tridacna (9) are monomj^ary. 

3. Leda (4) and Adacna (lO)Jiave a pallial sinus ; Annpa (16) has none. 

4. The form of tlie foot is usually characteristic of the families ; but sometimes it is 
OidajMvely modified. 

o. Diplodonta (11) has four gills. 

6. Pearly structure is variable even in species of the same genus. 

7. Crassatella (13) and Semele (16; have an internal ligament; in Solenella and 
Jsoarca (4) it is external. 

8. Anodon (16), Adacna, Serripes (10), and Cryptodon (11) are edentulous. 

9. Cor^M^a (18) and Pandora (19) are more inequivalve than Uieu- allies ; Chama, 
arcme//(2 (7) is equiValve. ' 

10. Hinnites (1), .Mtheria (6), Myochama and Chamostrea Q9) are irregular. I 

11. Pecfew is free, byssiferous, or fixed: Area free or byssiferous. This cliaractar 
varies with age and locality in the same species. It does not always depend on the 
form of the foot, as Lithodomus and Unyulina — boring shells- have the loot like 
Mytilus and Lucina. 

12. Novaculina is a river Solen, and Scaphida a fresh- water Area. 



COirCHIFEEA. 407 

Family I.— Ostreid^. 

Shell inequiYalve, slightly inequilateral, free or adherent, 
resting on one valve ; beaks central, straight ; ligament in- 
ternal ; epidermis thin ; adductor impression single, behind the 
centre ; pallial line obscure ; hinge usually edentulous. 

Animal marine ; mantle quite open ; very slightly adherent 
to the edge of the shell ; foot small and byssiferous, or obsolete ; 
gills crescent-shaped, 2 on each side ; adductor muscle composed 
of two elements, but representing only the posterior shell-muscle 
of other bivalves. 

The union of the Ostreidce and Fedinidoe, as proposed by the 
authors of the " History of British Mollusca," has not proved 
satisfactory. The genus Ostrea stands quite alone, and distinct 
from all the Feditiidoe in the structure of its gills, which are 
like those of Avicula, and by resting on its left valve. The shell 
also is more nacreous than that of the scallops 

OSTEEA, L. — OySTEE. 

Synonyms, Amphidonta and Pycnodonta, Pischer. Peloris, 
PoH. 

Tyjpe, 0. edulis, L. 

Examjple, 0. diluviana,. PI. XYI., Fig. 1. 

Shell irregular, attached by the left valve ; upper valve flat 
or concave, often plain ; lower convex, often plaited or 
foliaceous, and with a prominent beak; ligamental cavity 
triangular or elongated ; hinge toothless ; structure sub- 
nacreous, laminated, with prismatic cellular substance between 
the margins of the laminae. 

Animal with the mantle-margin double, finely fringed ; gills 
nearly equal, united posteriorly to each other and the mantle- 
lobes, forming a complete branchial chamber ; lips plain ; palpi 
triangular, attached ; sexes distinct.* 

Distribution, 70 species. Tropical and temperate seas. Norway, 
Black Sea, &c. 

Fossil, 200 species. Carb. — . United States, Europe, India. 

The interior of recent oyster- shells has a slightly nacreous 
lustre ; in fossil specimens an irregular cellular structure is 
often very apparent on decomposed or fractured surfaces. Fossil 
oysters which have grown upon Ammonites, Trigonice, &c., 
frequently take the form of those shells. 

In the " cock's-comb " oysters both valves are plaited; 0. 
i.diluviana sends out long root-like processes from its lower 

* The course of the alimentary canal in the common oyster is incorrectly repre- 
sented hy Poli, and copied ia the Crochard ed. of Cuvder. 



408 



MANUAL OF THE MOLLUSCA. 



valve. The "tree-oyster" {Dendrcstrea, Sw.) grows on the 
root of the mangrove. Oyster shells become very thick with 
age, especially in rough Water ; the fossil oyster of the Tagus 
( 0. longirostris) attains a length of two feet. The greatest enemy 
of oyster-banks is a sponge {Cliona), which eats into the valves, 
both of dead and living shells ; at first only small round holes, 
at irregular intervals, and often disposed in regular patterns, 
are visible ; but ultimately the shell is completely mined and 
falls to pieces. Natural oyster-banks usually occur in water 
several fathoms deep ; the oysters spawn in May and June, and 
the fry ("spats") are extensively collected and removed to 
artificial grounds, or tanks, where the water is very shallow ; 
they are then called " natives," and do not attain their full 
growth in less than five or seven years, whilst the " sea-oysters " 
are full-grown in four years. Native oysters do not breed freely, 
and sometimes many die in the spawning season ; they are also 
liable to be killed by frost. The season is from August 4 to May 12. 
I'rom 20,000 to 30,000 bushels of " natives " and 100,000 bushels 
of sea-oysters are annually sent to the London market. Many 
other species of oysters are eaten in India, China, Australia, &c. 

Green oysters " are those which 
have fed on confervce in the tanks. 
Sub-genera. Gryphcea, Lamarck. 
G. incurva, Sby. (section), Fig. 
215. Free, or very slightly at- 
tached ; left valve with a promi- 
nent, incurved umbo ; right valve 
small, concave. Fossil, 30 species. 
Lias — Chalk. Europe, India. 
PI. XVI., Fig. 2. Shell chama- 
shaped, attached by the left valve ; umbones sub-spiral, turned 
to the posterior side {i.e. reversed) ; right valve opercular. 
Fossil, 46 species. L. Oolite — Chalk. United States ; Europe. 
Dimya (Deshayesana), Eouault, 1859. Mem. Soc. Geol. 
b. III. 471, t. 15. Fig. 3. L. Eocene, Paris. The figure is most 
like an oyster, and the " second adductor impression," on 
account of which it is named Dimya^ is rather like the small 
anterior scar in Peden (Fig. 210). 

Anomia, L. 

Etymology, anomios, unequal. 
Example, A. Achaeus, PL XVI., Fig. 3. 
Synonyms, Fenestrella, Bolten; Cepa, Humph. Aenigmai 
Koch. 

Shell sub-orbicular, very variable, translucent, and slightl 




rig. 215. Gryphcea. 

Exogyra, Sby. E. conica. 



CONCHIFEEA. 409 

pearly within, attached by a plug passing through a hole or 
liotch in the right valve : upper valve convex, smooth, lamellar 
or striated ; interior with a sub-marginal cartilage-pit, and 
foujf muscular impressions, 3 sub-central, and one in front of 
the cartilage (see Eig. 213, p. 402) : lower valve concave, with a 
deep, rounded notch in front of the cartilage process ; disk with 
a single (adductor) impression. 

Animal with the mantle open, its margins with a short double 
fringe ; lips membranous, elongated ; palpi fixed, striated on 
both sides ; gills 2 on each side, united posteriorly, the outer 
laminae incomplete and free ; foot small, cylindrical, subsidiary 
to a lamellar and more or less calcified byssal plug, attached to 
the upper valve by three muscles ; adductor muscle behind the 
byssal muscles, small, composed of two elements; sexes dis- 
tinct ; ovary extending into the substance of the lower mantle- 
lobe. 

In A. pernoides, from California, there is an anterior [pedal) 
muscular impression in both valves. 

" There is no relationship of affinity between Anomia and 
Terehxitula, but only a resemblance through formal analogy; 
the parts which seem identical are not homologous." (Forbes.) 

The Anomiae are found attached to oysters and other shells, 
and frequently acquire the form of the surfaces with which 
their growing margins are in contact. They are not edible. 

Distrihution, 20 sj)ecies. North America, Britain, Black Sea, 
India, Australia, West America, Icy sea. Low water — 100 
fathoms. 

Fossil, 36 species. Oolite — . Chili, United States, Europe, 
India. 

Sub-genera. Placunomia (Cumingii), Broderip. Synonym, 
Pododesmus, Phil. P. macroschisma, PI. XYI., Pig. 4. Upper 
valve with only two muscular impressions ; the pedal scar 
radiately striated ; the byssal plug is often fixed in the lower 
valve, and its muscle becomes (functionally) an adductor. Dis- 
trihution, 13 species. "West Indies, Britain (P. patelliformis), 
New Zealand, California, Behring's Sea, Ochotsk. — 50 
fathoms. 

Limanomia (Grayana), Bouchard. Shell eared like Lima. 
Fossil, 4 species. Devonian ; Boulonnais, China ? 

Placiwa, Solander. — Window-Shell. 

Etymology, plahous, a thin cake. 

Example, P. sella, PL XYL, Fig. 5. 

Shell suborbicular, compressed, translucent, free, resting on 



410 MA^fUAL OF THE MOLLTTSCA. 

tlie rigM valve ; hinge area narrow and obscure ; cartilage 
supported by two diverging ridges in the right valve and cor- 
responding grooves in the left ; muscular impressions double, 
the larger element round and central, the smaller distinct and 
crescent shaped, in front of it. 

The Placunse are very closely allied to Anomia ; and many 
intermediate forms may be traced. The shell of each consists 
entirely of sub-nacreous, plicated laminae, peculiarly separable, 
and occasionally penetrated by minute tubuli. (Carpenter.) P. 
sella, called, from its shape, the "saddle-oyster," is remarkably 
striated. In P. placenta ^ PI. XVI., Pig. 6, the anterior carti- 
lage ridge is only half as long as the other, which appears to be 
connected with the economy of the shell when young ; in speci- 
mens 1 inch across, there is a pedal imnression below the 
cartilage grooves of the upper valve, and a shallow sinus in the 
margin of the lower valve, indicating a sHght byssal attach- 
ment at that age. 

Placuna* is essentially like Anomia, having the generative 
system attached to the right mantle-lobe, and the ventricle 
exposed. The mantle-margin is cirrated, and furnished with a 
curtain, as in Pecten ; the foot is tubular and extensile, but has 
no distinct muscles except the small one, whose existence in 
P. placenta (PL XYI., Fig. 6) we had predicated from examina- 
tion of the shell, f The small muscular impressions before 
and in the rear of the adductor are produced by suspensors 
of the gills. 

Distribution, 4 species. Scinde, North Australia, China. 

Sub-genera. Carolia, Cantraine, 1835 (after Prince Charles 
Bonaparte). Synonym, Hemiplacuna, Gr. Sby. Type, C. placu- 
noides, PL XVL, Pig. 7. Shell like Placuna; hinge, when 
young, like Anomia, with a byssal plug passing through a 
small deep sinus in front of the cartilage process, which is closed 
in the adult. Distribution, 3 species. (British Museum), Tertiary, 
Egypt; America? 

Placunopsis, Morris and Lycett. P. Jurensis, Eoemer. Sub-j 
orbicular, upper valve convex, radiately striated, or taking the/ 
form of the surface to which it adheres ; lower valve flat ; ligan 
mental groove sub-marginal, transverse ; muscular impression 
large, sub-central. Fossil 4 species. Lower Oolites, Europe. [ 

Placenta, Eetzius. Cartilage grooves slightly divergent, thb 
posterior one the longer of the two ; muscular impression sul}- 
central. 



* Original figures and descriptions will be found in the An. Nat. Hist. 1855, p. 2^ 
t This organ appears to represent the byssal-sheaih of Anomia, rather than the fbot, 
as there is no other opening for the passage of a bys&us. 



CONCHII'EEA. 411 

PEcten, 0. F. Miiller. Scallop. 

Mtymology, peden, a comb. 

Type, P. maxinnis (Janira, Sdnim.) 

Synonyms, Argus, Poll. Discites, ScM. Amusiliin, Miililfeldt. 

Shell sub -orbicular, regular, resting on the rigbt valve, 
usually ornamented with, radiating ribs ; beaks approximate, 
eared ; anterior ears most prominent ; j)osterior side a little 
oblique ; right valve most convex, with a notch below the front 
ear; hinge-margins straight, united by a narrow ligament; 
cartilage internal, in a central pit ; adductor impression double, 
obscure ; pedal impression only in the left valve, or obsolete 
(Pig. 210). 

Animal with the mantle quite open, its margins double, the 
inner pendent like a curtain .^rt^*^^-^'" 

(m) finely fringed ; at its 
base a row of conspicuous 
round black eyes [ocelli) sur- 




rounded by tentacular fila- 
ments ; gills (&r) exceed- 
ingly delicate, crescent- 
shaped, quite disconnected 
posteriorly, having separate 
excurrent canals ; lips folia- ^^g- ^le. Fedenvanus* 

ceous ; palpi truncated, plain outside, striated within ; foot 
finger-like, grooved, byssiferous in the young. 

The Scallop (P. maximus) and " quin " (P. opercularis) are 
esteemed delicacies ; the latter covers extensive banks, especially 
on the north and west of Ireland, in 15 to 25 fathoms water. 
The scallop ranges from 3 — iOfathoms ; its body is bright orange, 
or scarlet, the mantle fawn-colout, marbled with brown; the 
shell is used for " scalloj)ing " oysters, formerly it was em- 
ployed as a drinking-cup, and celebrated as such in Ossian's 
" hall of shells." An allied species has received the name of 
"St. James's shell" (P. Jacohceus); it was worn by pilgrims 
to the Holy Land, and became the badge of several orders of 
knighthood, t 

Most of the Pectens spin a byssus when young, and some, 
like P. varius, do so habitually ; P. niveits moors itself to the 
fronds of the tangle {Laminaria). 

* The Pectens do not open so wide as here represented ; their " curtains " remain 
ii. contact at one point on the posterior side, separating the branchial from the exhalen* 
currents . 

t "VVlien the monks of the ninth century converted the fisherman of Gennesaret into 
a Spanish warrior, they assigned him the scallop-shell for his "cognizance." (Moule's 
" Eeralui-y of Fish.") 

T 2 



412 MANUAL OP THE MOLIUSCA. 

The Rev. T>. Landsborougli observed the fry of P. opercAdar s, 
wlien less than tlie size of a sixpence, swimming in a pool of 
sea-water left by the ebbing of the tide. " Their motion was 
rapid and zig-zag ; they seemed, by the sudden opening and 
closing of their valves, to have the power of darting like an 
arrow throngh the water. One jerk carried them some yards, 
and then by another sudden jerk they were oflF in a moment on 
a different tack." 

The shell of Ptden and the succeeding genera consists almost 
exclusively of membranous laminae', coarsely or finely corru- 
gated. It is composed of two very distinct layers, differing in 
colour (and also in texture and destructibility), but having 
essentially the same structure, Traces of cellularity are some- 
times discoverable on the external surface ; P. nobilis has a 
distinct prismatic-cellular layer externally. (Carpenter.) 

Sub-genera, Neithea, Drouet, Yola, Klein. P. quinque- 
costatus and other fossil species with concavo-convex valves 
and distinct hinge-teeth ; the inner layers of these shells are 
wanting in all specimens from the English chalk. 

Pallium, Schum. P. plica, PL XVI., Pig. 8. Hinge obscurely 
toothed. 

Hinnites (Cortesii) Defr. P. pusio, PI. XVI., Fig. 10. Shell 
regular and byssiferous when young ; afterwards cementing its 
lower valve and becoming more or less irregular. 

Distrihution, 2 species. 

Fossil, Trias ? Upper Greensand — , Europe. 

Hemi/peden, A. Adams. H. Eorbesianus, PL XVI., Pig. 9. 
Shell hyaline, posterior ears obsolete, anterior prominent; 
right valve flat, byssal sinus deep ; structure permeated by 
microscopic tubuli, as in Lima. 

Amusium, Elein. Shell nearly equivalved, gaping in front 
and behind ; smooth outside, generally marked with radiating 
grooves inside. 

Pisfribution, 176 sjiecies. World-wide; Nova-Zembla — Cape 
Horn ; — 200 fathoms. 

Fossil, 450 species (including Aviculo-pecten). Carb.- 
World-wide. 

Lima, Bruguiere. 

Etymology, lima, a file. 

Example, L. squamosa, PL XVI., Pig. 11. (Ostrea lima, Li 
Synonyms, Plagiostoma (Llhwyd), Sby. P. cardiiform^, 
PLXVL, Pig. 12. 

Shell equivalve, compressed, obliquely oval ; anterior si^e 



CONCHIFEEA. 413 

straigM, gaping, posterior rounded, Tisually close ; nmbones 
apart, eared ; valves smooth, punctate -striate, or radiately 
ribbed and imbricated; hinge area triangular, cartilage pit 
central ; adductor impression lateral, large, double ; pedal 
scars 2, small. 

Animal, mantle-margins separate, inner pendent, fringed 
with long tentacular filaments, ocelli inconspicuous ; foot 
finger-like, grooved ; lips with tentacular filaments, palpi 
small, striated inside ; gills equal on each side, distinct. 

The shell is always white ; its outer layer consists of coarsely- 
plicated membranous lamellae ; the inner layer is perforated by 
minute tubuli, forming a complete network. (Carpenter.) 

The Limas are either free or spin a byssus ; some make an 
artificial burrow when adult, by spinning together sand or coral- 
fragments and shells, but the habit is not constant. (Eorbes.) 
The burrows of Z. hians are several times longer than the shell, 
a,nd closed at each end. (Charlesworth.) "This species is 
pale or deep crimson, with an orange mantle ; when taken out 
of its nest it is one of the most beautiful marine animals to look 
upon, it swims with great vigour, like the scallop, by opening 
and closing its valves, so that it is impelled onwards or upwards 
in a succession of jumps. The filaments of the fringe are 
easily broken ofi", and seem to live many hours after they are 
detached, twisting themselves like worms." (Landsborough.) 
L. spinosa has conspicuous ocelli, and short filaments. 

Sub-genera, Limatula, S. Wood. L. sub-auriculata, PL XYI., 
Fig. 13. Valves equilateral; 8 species. Greenland — Britain. 
Fossil, Miocene — . Europe. 

Limcea, Bronn. L. strigilata, PI. XYI. Pig. 14.* Hinge 
minutely toothed. 

Fossil, 4 species. Lias — Pliocene. The recent Limcea? 
Sarsii (Loven), Norway (=L. crassa of the ^gean ?) has the 
mantle-border plain. Some of the larger recent species have 
obscure lateral teeth. 

Distribution, 20 species. Norway, Britain, West Indies, 
Canaries, India, Australia ; 1 — ] 50 fathoms. The largest living 
species {L. excavata, Chemn.) is found on the coast of Norway. 

i'^osstZ, 200 species. Carb.? Trias — . United States, Europe, 
India. The so-called Plagiostoma spinosum is a Spondylus. 

Spondylus (Pliny) L. Thorny- oyster. 

Type, S. g8edaroj)us, L. 

Example, S. princeps, PL XVI., Eig. 15 

* Aitev Bronn ; the figure in Brocclii does not show the teeth. 



414 MAJTUAL OF THE MOLLUSCA. 

Synonyms, Diancliora, Sby. Podopsis, Lam. Pachytes, Defr. 

Shell irregular, attached by tlie right valve, radiately ribbed, 
spiny or foliaceous ; -umbones remote, eared ; lower valve with 
a triangular binge-area, cartilage in a central groove, nearly or 
quite covered ; binge of two curved interlocking teetb in each 
valve ; adductor impression double. 

Animal, with the mantle open and gills separate, as in Peden; 
lips foliaceous, palpi short ; foot small, cylindrical, truncated. 

In aged specimens the circular portion of the muscular scar 
exhibits dendritic vascular markings. The lower valve is 
always most spiny and least coloured ; in some species (like 8. 
imperialis) the shell is scarcely, if at all, attached by its beak 
or spines. The inner shell-layer is very distinct from the outer, 
and always wanting in fossil specimens from calcareous rocks, 
then called Dianchoroe. Specimens from the Miocene of St. 
Domingo, which have lost this layer, contain a loose mould of 
the original interior. Water- cavities are common in the inner 
layer, the border of the mantle having deposited shell more 
rapidly than the umbonal portion. (Owen, Mag. Nat. Hist. 
1838, p. 409.) 

Distribution, 68 species. "West Indies, Canaries, Mediter- 
ranean, India, Torres Straits, Pacific, West America : — 105 
fathoms. 

Fossil, 80 species. Carb — . Europe, United States, India. 

Sub-genus, Pedum, Brug. P. spondyloides, PI. XYI., 
Pig. 16. Shell thin, smooth, compressed, attached by a byssus 
passing through a deep notch in the right valve. Inhabits 
coral-reefs, where it is found half-embedded ; Eed Sea, Indian 
Ocean, Mauritius, Chinese Seas. 

Plicattjla, Lamarck. 

Etymology, plicatus, plaited. 

Type, P. cristata, PL XYL, Pig. 11 

Shell irregular, attached by the umbo of the right valve, 
valve smooth qr plaited ; hinge-area obscure ; cartilage quit 
internal ; hinge-teeth, two in each valve ; adductor scar simpl^ 

Animal resembles spondylus. 

Distribution, 9 species. West Indies, India, Philippine 
Australia, West America. 

Fossil, 40 species. Trias — . United States, Europe, Algeija, 
India. 

P. Mantelli (Lea) Alabama, has the valves eared. 




CON-CHIFEEA. 415 

Family II. — ^Ayictjlid^. "Wing-shells. 

Shell inequivalve, very oblique, resting on the smaller (right) 
valve, and attached by a byssus ; epidermis indistinct : outer 
layer prismatic-cellular (Fig. 217), in- 
terior nacreous ; posterior muscular im- 
pression large, sub-central, anterior small, 
within the umbo ; pallial line, irregularly 
dotted ; hinge-line straight, elongated ; 
umbones anterior, eared, the posterior 
ear wing-like ; cartilage contained in one 
or several grooves ; hinge edentulous, or 
obscurely toothed. 

Animal with the mantle-lobes free, rig. 217. Pm^ia.* 

their margins fringed ; foot small, spinning a byssus ; gills two 
on each side, crescent-shaped, entirely free [Desh.) or united to 
each other posteriorly, and to the mantle (as in the Oyster, and 
not as in Pecten). 

The wing-shells, or pearl-oysters, are natives of tropical and 
temperate seas ; there are no living species in northern latitudes, 
where fossil forms are very numerous. 



AviCTJLA (Klein), Bruguiere. 

Etymology, avicula, a little bird. 

Tijpe, A. hirundo, PI. XVI., Fig. 18. 

Shell obliquely oval, very inequivalve; right valve with a 
byssal sinus beneath the anterior ear; cartilage pit single, 
oblique ; hinge with one or two small cardinal teeth, and an 
elongated posterior tooth, often obsolete ; posterior muscular 
impression (adductor and pedal) large, sub-central; anterior 
(pedal scar) small, umbonal. 

Animal (of meleagrina) with mantle globes united at one point 
by the gills, their margins fringed and furnished with a pendent 
curtain ; curtains fringed in the branchial region, plain behind ; 
foot finger-like, grooved; byssus often solid, cylindrical, with 
an expanded termination ; pedal muscles four, posterior large 
in front of tie adductor; adductor composed of two elements; 
retractors of the mantle forming a series of dots, and a large 
spot near the adductor ; lips simple ; palpi truncated ; gills 
equal, crescentic, united behind the foot. (British Museum.) 

* The cellular structure may be seen wifh a hand-lens, in the thin margin of the 
shell, by holding it up to the light ; or on the edges of broken fragments. 



416 MANUAL OF THE MOLLUSCA. 

Distribution, 25 species. Mexico, South Britain, Mediter- 
ranean, India, Pacific : — 20 fathoms. 

Fossil, 300 species. Lower Silurian — . "World-wide. 

Sub-genera Maleagrina, Lam. Margaritophora, Muhlfeldt. 
M. margaritifera, PI. XYL, Pig. 19. The "pearl-oysters" are 
less oblique than the other aviculoe, and their valves are flatter 
and nearly equal ; the posterior pedal imj)ression is blended 
with that of the great adductor. They are found at Madagascar, 
Ceylon, Swan Eiver, Panama, &c. Manilla is the chief port to 
which they are taken. There are three principal kinds, which are 
worth from £2 to £4 per cwt. : — 1. The silver-lipped, from the 
Society Islands, of which about twenty tons are annually im- 
ported to Liverpool. 2. The black-lipped, from Manilla, of 
which thirty tons were imported in 1851. 3. A smaller sort 
from Panama, 200 tons of which are annually imported ; in 
1851 a single vessel brought 340 tons. (T. 0. Archer.) These 
shells afi'ord the " mother-o' -pearl" used for ornamental pur- 
poses ; and the " oriental" pearls of commerce (p. 30, 31). Mr. 
Hope's pearl, said to be the largest known, measures 2 inches 
long, 4 round, and weighs 1,800 grains. Pearl-oysters are found 
in about 12 fathom water ; the fisheries of the Persian Gulf and 
Ceylon have been celebrated from the time of Pliny. 

Malleus, Jjam. M. vulgaris, PI. XYL, Pig. 20. The "hammer- 
oyster " is remarkable for its form, which becomes extremely 
elongated with age; both ears are long, and the umbones 
central. When young it is like an ordinary Avicula, with a 
deep byssal notch in the right valve. 6 species. China, 
Australia. 

Vulsella, Lam. Y. lingulata, PL XYL, Pig. 21. Synonym, 
Beniella, Sw. Shell, oblong, striated, sub-equivalve ; umbones 
straight, earless. Often found imbedded in living sponges. 
Distribution, Y species. Eed Sea, India, Australia, Tasmania. 
Fossil, 1 species. U. Chalk — . Britain, France. 

Fteroperna, Lycett, 1852. P. costatula, Desl. SJiell with a 
long posterior wing ; hinge-line bordered by a groove ; anterior 
teeth numerous, minute ; posterior one or two, long, nearly 
parallel with the hinge-margin. Fossil, 3 species. Bath oolite 
Britain, Prance. 

? ^wce?/a (Pallasii), 1846. Yery inequivalve ; left umbo pro-/ 
minent, earless ; right valve small and flat, with a deep sinus 
beneath the small anterior ear. Fossil, 4 species, Permian 
Gault. Europe. " In ^. cygnipeswe find no trace of prismati^ 
cellular structure or nacre, but the coarsely corrugated ani 
somewhat tubular structure of the Pectens." (Carpenter.) 



Ambonychia (bellistriata), Hall, 1847. Nearly eq^uiyalve, 
gibbose, oblique, obtusely -winged. A. vetusta (Inoceramus, 
Sby.) is concentrically furrowed ; the right valve has a small 
anterior ear (usually concealed) separated by a deep and narrow 
sinus. Fossil) 12 species. Lower Silurian — Garb. United 
States, Europe. 

? Cardiola (interrupta), Broderip, 1844. Equivalve, gibbose, 
obliquely oval, radiately ribbed ; beaks prominent ; hinge-area 
short and flat. Fossil, 17 species. Upper Silurian — Dev. 
United States, Europe. 

? Eurydesma (cordata), Morris ; Devonian? New South Wales. 
Shell equivalve, sub -orbicular, ventricose, very thick near the 
beaks ; ligimental area long, wide, sub-internal ; byssal groove 
close to the umbo ; right valve with a large, blunt hinge-tooth ; 
adductor impression single, placed anteriorly; pallial line dotted. 

Pterinea (Isevis), Goldf. 1832. Shell thick, rather inequivalve, 
very oblique and broadly winged ; beaks anterior; sinus shallow ; 
hinge-area long, straight, narrow, striated lengthwise ; ante- 
rior teeth few, radiating ; posterior teeth laminar, elongated ; 
anterior (j)edal) scar deep, posterior (adductor) impression large, 
very eccentric. Fossil, 32 species. Lower Silurian — Garb. 
United States, Europe, Australia. Pteronites (angustatus) 
M'Goy, 1844, is thinner and has the teeth, &c., less developed. 

Monotis, Bronn, 1830. M. Salinaria, Schl. Trias, Hallein. 
Obliquely oval, compressed, radiated; anterior side short, 
rounded ; posterior slightly eared. 

Synonym, P Halohia (salinarum) Br. 1830. Trias, Hallstadt. 
Semi-oval, radiated, compressed, with a shallow sinus in front ; 
hinge-line long and straight. 

PosiDOisroMTA, Bronn. 

Synonym, Posidonia, Br. 1838 (not Konig). Poseidon, Neptu-pe. 

Type, P. Becheri, PL XYL, Fig. 22. 

Shell thin, equivalve, compressed, earless, concentrically 
furrowed ; hinge-line short and straight, edentulous. 

Fossil, 50 species. Lower Silurian — Trias. United States, 
Europe. 

P Ayictjxo-I'Ectek, M'Coy, 1852. 

Type, Pecten granosus, Sby. Min. Con. t. 574. 

Shell inequivalve, sub -orbicular, eared ; hinge-areas flat, with 
several long, narrow cartilage furrows, slightly oblique on each 
side of the umbones ; right valve with a deep and narrow byssal 
s .nus beneath the anterior ear ; adductor impression large, 

T 3 



418 MAKTJAL OF THE MOtLTTSCA. 

simple, sub-central ; pedal scar small and deep, beneatli tlie 
umbo. 

Fossil (see Peoten). Lower Silurian — Carb. Spitzbergen — 
Australia. 

GrERViLLiA, Defrance. 

Etymology, dedicated to M. Gerville, a Frencb naturalist. 

Example, G. anceps, PI. XTII., Fig. 1. 

Shell like Avicula ; elongated ; anterior ear small, posterior 
wing-like ; area long and flat, cartilage pits several, wide apart ; 
hinge-teetb. obscure, diverging posteriorly. 

Fossil, 37 species. Carb. — Cbalk. Europe. 

Bub-genus ? BakewelUa, King. B. ceratopbaga, Scbl. Fossil^ 
5 species. Permian, Britain, Germany, Russia. Shell small, 
inequivalve, cartilage pits 2 — 5 ; binge witb anterior and pos- 
terior teeth; anterior muscular impression and pallial line 
distinct. 

pERlsrA, Bruguiere. 

Etymology, perna, a sbell-fisb (resembling a gammon), Pliny. 

Synonyms, Melina, Eetz. Isognomon, Klein. Pedalion, 
Solander. 

Type, P. epbippium, L. PL XYIL, Pig. 2. 

Shell nearly equivalve, compressed, sub-quadrate ; area wide, 
cartilage pits numerous, elongated, close-set ; rigbt valve with 
a byssal sinus ; muscular impression double. 

Tbe Pernas vary in form like tbe Aviculce ; some are very 
oblique, some very inequivalve, and many fossil species have 
tbe posterior side produced and wing-like. In some Tertiary 
Pernas tbe pearly layer is an incb tbick. 

JJistrihution, 18 species. Tropical seas; West Indies ■ — India 
— West America. 

Fossil, 30 species. Trias — . United States, Cbili, Europe. 

Suh-genera, Crenatulo,, Lamk. C. viridis, PL XYL, Fig. 24. 
Shell tbin, oblong, compressed ; byssal sinus obsolete ; cartilage 
pits shallow, crescent-sbaped. Distribution, 8 species, Nortb 
Africa, Eed Sea — Obina ; in sponges. Fossil, 4 species, 

Hypotrema, D'Orb, 1853. H. rupellensis ( = ? Pulvinites 
Adansonii, Defrance, 1826) ; Coral-rag, Rocbelle. Shell oblong, 
inequivalve; rigbt valve flat or concave, with a round byssal , 
foramen near the hinge; left valve convex, with a muscular| 
impression near the umbo ; hinge-margin broad, curved, witl 
about twelve close-set transverse cartilage grooves. 



COHCaiFEBA. 419 

Inoceramtjs, Sowerby (1814). 

Etymology, is (inos), fibre, heramos^ shell. 

Example, I. siilcatus, PL XYII., Fig. 3. 

Synonym, Catillus, Brongn. 

Shell inequivalye, ventricose, radiately or concentrically 
furrowed, nmbones prominent ; binge-line straight, elongated ; 
cartilage pits transverse, numerous, close-set. 

This genus difiPers from Perna cbiefiy in form. /. involutus 
has the left valve spiral, the right opercular. I. Cuvieri attains 
the length of a yard. Large flat fragments are common both 
in the chalk and flints, and are often perforated by the Gliona. 
Hemispherical pearls have been found developed from their 
inner -surface, and spherical pearls of the same prismatic- cellular 
structure occur detached, in the chalk. (Wetherell.) The Ino- 
cerami of the gault are nacreous. 

Fossil, 1o species. ? Silurian — Chalk. South America, 
United States, Europe, Algeria, Thibet. 

Pinna, L. 

Etymology, pinna, a fin or wing. 

Tijpe, P. squamosa, PL XYL, Fig. 23. 

Shell equivalve, wedge-shaped ; umbones quite anterior ; 
posterior side truncated and gaping ; ligamental groove linear, 
elongated ; hinge edentulous ; anterior adductor scar apical, 
posterior sub-central, large, ill-defined ; pedal scar in front of 
posterior adductor. 

Animal with the mantle doubly fringed ; foot elongated, 
grooved, spinning a powerful byssus, attached by large triple 
muscles to the centre of each valve ; adductors both large ; palpi 
elongated ; gills long. 

Distribution, 30 species. United States, Britain, Mediter- 
ranean, Australia, Pacific, Panama. 

Fossil, 60 species. Devonian — . United States, Europe, 
South India. 

The shell of the Pinna attains a length of two feet ; when 
young it is thin, brittle, and translucent, consisting almost 
entirely of prismatic cell-layers ; the pearly lining is thin, 
divided, and extends less than half-way from the beak. Some 
fossil Pinnas crumble under the touch into their component 
fibres. The living species range from extreme low water to 
60 fathoms ; they are moored vertically, and often nearly buried 
in sand, with knife-like edges erect. The byssus has sometimes 
been mixed with silk, spun, and knitted into gloves, &c. (Brit. 



420 MANUAL OF THE MOLLXTSCA. 

Mus.) A little crab whicli nestles in tlie mantle and gills of the 
Pinna, was anciently believed to bave formed an alliance witb. 
tbe blind sbell-fisb, and received tbe name of Pinna-guardian 
{Pinnoteres) from Aristotle ; similar species infest tbe Mussels 
and Anomice of tbe Britisb coast. 

8ub~genus, Trichites (Plott), Lycett. T. Plottii, Llbwyd. 
(" Pinnigene," Saussure.) Shell tbick, inequivalve, somewbat 
irregular, margins undulated. Fossil, 5 species. Oolitic strata 
of England and Prance. Fragments an incb or more in tbick- 
ness are common in tbe Cotteswold-bills ; full-grown individuals 
are supposed to bave measured a yard across. 

Family III. — Mttilidjs. Mussels. 

Sliell equivalve, oval or elongated, closed, umbones anterior, 
epidermis tbick and dark, often filamentose ; ligament internal, 
sub -marginal, very long ; binge edentulous ; outer sbell layer 
obscurely prismatic- cellular ; * inner more or less nacreous ; 
pallial line simple ; anterior muscular impression small and 
narrow, posterior large, obscure. 

Animal marine or fluviatile, attacbed by a byssus ; mantle- 
lobes united between tbe sipbonal openings ; gills two on eacb 
side elongated, and united bebind to eacb otber and to tbe 
mantle, dorsal margins of tbe outer and innermost laminae free ; 
foot cylindrical, grooved. 

Tbe members of tbis family exbibit a propensity for conceal- 
ment, frequently spinning a nest of sand and sbell-fragments, 
burrowing in soft substances, or secreting tbemselves in tbe 
burrows of otber sbells. 

Mytiltjs, L. Sea-mussel. 

Example, M. smaragdinus, PI. XYIL, Pig. 4. 

Shell wedge-sbaped, rounded bebind; umbones terminal, 
pointed ; binge-teetb minute or obsolete ; pedal muscular im- 
pressions two in eacb valve, small, simple, close to tbe adductors. 

Animal witb tbe mantle- margins plain in tbe anal region, 
and projecting sligbtly; brancbial margins fringed; byssus 
strong and coarse ; gills nearly equal ; palpi long and pointed, 
free. 

Tbe common edible mussel frequents mud-banks wbicb are/ 
uncovered at low-water ; tbe fry abound in water a few fatbom^ 
deep ; tbey are full-grown in a single year. Prom some unj 

* A thin layer of minute cells may frequently be detected immediately under 
epidermis. (Carpenter.) 



CONCHIFEHA. 421 

known cause tliey are at times extremely deleterious. The 
consumption of mussels in Edinburgh and Leith is estimated 
at 400 bushels (= 400,000 mussels) annually ; enormous quan- 
tities are also used for bait, especially in the deep sea fishery, 
for which purpose thirty or forty millions are collected yearly 
in the Firth of Forth alone. (Dr. Enapp.) Mussels produce 
small and inferior pearls. At Port Stanley, Falkland Islands, 
Mr. Macgillivray noticed beds of mussels which were chiefly 
dead, being frozen at low-water. M. hilocularis (Septifer, 
Eecluz) has an umbonal shelf for the support of the anterior 
adductor, like Breissena ; it is found at Mauritius and Australia. 
M. exustus (Brachydontesj Sw.) has the hinge-margin denti- 
culated continuously. 

I)ist?^ihution, 65 species. World-wide. Ochotsk, Behring's 
Sea, Russian Ice-meer; Black Sea, Cape Horn, Cape, New 
Zealand. 

Fossil, 100 species. Silurian — . United States, Europe, 
South India. 

? Myalus-a, Koninck, 1842. 

TypeS) M. Goldfussiana, Eon, Carb. M. acuminata, Sby. 
Permian. 

Shell equivalve, mytili-form ; beaks nearly terminal, septi- 
ferous internally; hinge-margin thickened, flat, with several 
longitudinal cartilage-grooves ; muscular impressions two ; 
pallial line simple. 

Fossil, 6 species. Carb. — Permian. Euroj^e. The liga- 
mental area resembles that of the recent Area ohliquata, 
Chemn. India. 

MoDiOLA, Lam. Horse-mussel. 

Etymology, modiolus, a small measure, or drinking-vessel. 

Example, M. tulipa, PI. XYIL, Fig. 5. M. modiolus, p. 403, 
Eig. 214. 

Shell oblong, inflated in front ; umbones anterior, obtuse ; 
hinge toothless ; pedal impressions three in each valve, the 
central elongated ; epidermis often produced into long beard- 
like fringes. 

Animal with the mantle-margin simple, protruding in the 
branchial region ; byssus ample, fine ; palpi triangular, pointed. 

The Modiolcs are distinguished from the Mussels by their 
habit of burrowing, or spinning a nest. Low water — 100 
fathoms. 



422 MANTJAL OF THE MOLLtTSCA. 

Distribution^ 70 species, cHefly tropical; M. modiolus. Arctic 
seas — Britain. 

Fossil, 150 species. Silurian ? Lias — . United States, 
Europe, Thibet, South. India. 

Sub-genera, Lithodomus, Cuv. M. lithophaga, PI, XTII., 
Pig. 7. Shell cylindrical, inflated in front, wedge -shaped behind; 
epidermis thick and dark; interior nacreous.* Distribution, 
40 species. West Indies — New Zealand. Fossil, 35 species. 
Carb. — , Eui'ope, United States. The "date-shell" bores 
into corals, shells (Pig. 25, p. 34), and the hardest limestone 
l^ocks ; its burrows are shaped like the shell, and do not admit 
of free rotatory motion. The animal, which is eaten in the 
Mediterranean, is like a common mussel ; in L. patagonicus the 
siphons are produced. Like other burrowing shell-fish, they 
are luminous. Perforations of Litliodomi in limestone cliffs, 
and in the columns of the Temple of Serapis at Puteoli, have 
afforded conclusiTe evidence of changes in the level of sea- 
coasts in modern times. (Lyell's " Principles of Greology.") 

Crenella, Brown. 0. discors, PI. XVII. , Fig. 8. (Lanistes, 
Sw. Modiolaria, Beck.) Shell short and tumid, partly smooth, 
and partly ornamented with radiating striae; hinge-margin 
crenulated behind the ligament ; interior brilliantly nacreous. 
Animal with the anal tube and branchial margins prominent. 
Distribution, 24 species. Temperate and arctic seas ; Nova 
Zembla, Ochotsk, Britain, New Zealand. Low water — 40 
fathoms. Spinning a nest, or hiding amongst the roots of sea- 
weed and corallines. 31. marmorata, Porbes, burrows in the 
test of Ascidia. Fossil, 12 species. Upper Greensand — . 
Europe. 

Modiolarca (trapezina), Gray ; Falkland Islands — Kerguelen, 
attached to floating sea-weed ; mantle-lobes united, pedal open- 
ing small, foot with an expanded sole, front adductor round. 
M. ? pelagica, PL XVIL, Pig. 6, is found burrowing in floating 
blubber, off the Cape. (Porbes.) 2 living species. 

? Mytilimeria (Nuttallii), Conrad. Shell irregularly oval, thin, 
edentulous, gaping posteriorly ; umbones sub-spiral ; ligament 
short, semi-internal. Distribution, California ; animal gre- 
garious, forming a nest. 

Modiolopsis (mytiloides). Hall, 1847 ( = Cypricardites, part, 
Conrad. Lyonsia, part, D'Orb.). Shell like modiola, thin and| 
smooth, front end somewhat lobed; anterior adductor scar/ 



* The outer shell-layer has a tubiilar structure ; the ttibes are excessively minut^ 
seldom brandling, oblique and parallel. ''Cai'penter. ) 



coKcsirEEA. 423 

large and oval. Fossil, 15 species. Silurian, United States, 
Europe. 

? Orthonotus (pholadis), Conrad. Lower Silurian, New York. 
Shell elongated, margins parallel, umbones anterior, back 
plaited.* 

Myrina, Adams. Modiola pelagica, bas tbe mantle open; 
tbe shell is peculiar from the large size of tbe anterior muscular 
impression; and tbe subcentral umbones distinguish it from 
Modiolarca. 

Hoplompfilus {crSLSsus), Sdbgr. Devonian, Nassau. Shell with 
a muscular plate in the umbo, like Septifer. The Mytilus 
sqaamosus, Sby. Magnesian limestone, Brit., has a similar plate. 

HiPPOMYA. Salter. 

Shell gibbous, with anterior inflated close beaks, a long 
cardinal edge ; anterior edge short, rounded, and separated by a 
strong sinus from the inflated posterior ridge and slope. 

Fossil, 1 species. Devonian. 

Dreisseista, Van Beneden. 

Etymology, dedicated to Dreyssen, a Belgian physician. 

Synonyms, Mytilomya, Cantr. Congeria, Partsch. Ticho- 
gonia, Eossm. 

Type, D. polymorpha, PL XYII., Fig. 9. (Mytilus Yolgse, 
Chemn.) 

Shell like Mytilus, without its pearly lining ; inner layer com- 
posed of large prismatic shells ; um- 
bones terminal ; valves obtusely keeled ; 
right valve with a slight byssal sinus ; 
anterior adductor supported on a shelf 
within the beak ; pedal impression single, "^ 
posterior. 

Animal with the mantle closed ; byssal 
orifice small; and siphon very small, coni- 
cal, plain, branchial prominent, fringed ^ig* 218. Dreissena. 
inside ; palpi small, triangular ; foot-muscles short and thick, 
close in front of the posterior adductor. 

D. polymorpha is a native of the Aralo-Caspian rivers ; in 
1824 it was observed by Mr. J. Sowerby in the Surrey docks, 

* Hall and Salter employ the name Ortlionotus for sneli shells as Solen constrictus 
Sandb. Devonian, G-ermanr : Smiguinolites angidiferus, M'Coy, tJ. Silurian, Kendal ; 
and Solenopsis minor. M'Coy, Garb, limestone, Ireland. M. D'Orbigny has mistaken 
the plaits for teeth, and placed the genus with Nucula. The recent M. plicata^ Lam., 
from Nicohar Islands, has the same long, straight back and plaited dorsal region. 




424 MANUAL OF THE MOLLtJSCA, 

to whicli it appears to have been brought with foreign timber, 
in the holds of vessels* It has since spread into the canals, 
docks, and rivers of many parts of England, France, and 
Belgium, and has been noticed in the iron water-pipes of 
London, incrusted with a ferruginous deposit. (Cunnington.) 

Distribution^ 15 species. Europe, America, Africa. 

Fossil^ 13 species. Eocene^ — . Britain, Grermany. 

Family IT. — Aecad^. 

Sliell regular, equivalve, with strong epidermis ; hinge with 
a long row of similar, comb-like teeth ; pallial line distinct ; 
muscular impressions subequal. Structure corrugated, with 
vertical tubuli in rays between the ribs or striae. (Carpenter.) 

^mwaZ with the mantle open; foot large, bent, and deeply 
grooved ; gills very oblique, united posteriorly to a membranous 
septum. 

Aeca, L. 

Etymology, area, a chest. 

Tijpe, A. Nose, PL XVII., Pig. 12. 

8yno7iyms,^arha.tisii Grray; Anomalocardia, Klein; Scapharca, 
Gray ; Scaphula, Benson. 

Examples, A. granosa, PL XVIL, Fig. 10. A. pexata, Fig. 11. 
A. zebra, Fig. 13. 

Shell equivalve or nearly so, thick, sub-quadrate, ventricose, 
strongly ribbed or cancellated ; margins smooth or dentated, 
close or sinuated ventrally ; hinge straight, teeth very numerous, 
transverse ; umbones anterior, separated by a flat, lozenge- 
shaped ligamental area, with numerous cartilage-grooves; 
pallial line simple ; posterior adductor impression double ; 
pedal scars 2, the posterior elongated. 

Animal with a long pointed foot, heeled, and deeply groved ; 
mantle furnished with ocelli ; palpi ; gills long, narrow, less 
striated externally, continuous with the lips ; hearts two, each 
with an auricle. 

The name JBysso-arca was chosen unfortunately by Swainson, 
for the typical species of the genus, in which the byssal orifice 
is sometimes very large (PL XYIL, Fig. 13). The byssus is a 
horny cone, composed of numerous thin plates, occasionally 
becoming solid and calcareous ; it can be cast off and re-formed 
with great rapidity. (Forbes.) The Areas with close valves| 
have the left valve a little larger than the right, and mor( 
ornate. 

The Bysso-arks secrete themselves nder stones at low water/ 



CONCniFERA. 425 

in crevices of rocks, and the empty burrows of boring mollusks ; 
they are often much worn and distorted. The genus Palaarca 
probably belongs here ; we have not been able to ascertain the 
generic characters ; but they may be found in the Memoirs of 
the Geol. Surv., Canada, Yol. III., under the head Cyrtodonta. 

Distribution, 140 species. World wide, most abundant in warm 
seas; low water — 230 fathoms {A. imbricata, Poll). Prince- 
Eegent Inlet {A. glacialis). A scapJmla, Benson, is found in 
the Ganges and its branches, from Calcutta to Humeerpoor on 
the Jumna, 1,000 miles from the sea. A second species has 
been found in the river Tenasserim., Birmah. The hinge is 
edentulous in the centre, and the posterior teeth are laminar 
and branched ; the elements of the posterior muscular impres- 
sion are distinct. 

Fossil, 400 species. Lower Silurian — . United States, 
Europe, South India. 

CucTTLL^A, Lamarck. 

Etymology, cuculJus, a cowl. 

TyjJe, C. concamerata, PL XYII., Pig. 14. 

Shell sub-quadrate, ventricose ; valves close, striated ; hinge- 
teeth few and oblique, parallel with the hinge-line at each end ; 
posterior muscular impression bounded by an elevated ridge. 

Distribution, 2 species. Mauritius, Nicobar, China. 

Fossil, 240 species. Lower Silurian. North America, Pata- 
gonia, Europe. 

Sub-genus, Macrodon, Lycett. M. Hirsonensis, PL XYII., 
Pig. 15. Shell with, a few oblique anterior teeth and one or 
more long laminar posterior teeth. The Ark-shells of the 
Palaeozoic and secondary strata have their anterior teeth more 
or less oblique, like Area, the posterior teeth parallel with the 
hinge-line like Cucullcea ; their valves are close or gaping below ; 
their umbones frequently sub-spiral ; and the hinge-area is 
often very narrow, and in some species only the posterior moiety 
is visible. 

Parallelopipedum, Klein. The outermost hinge-teeth short, 
and perpendicular to the hinge-line; teeth developed along 
the whole length of the hinge. 

PECTUTsrciJLTJS, Lam. 

Type, P. pectiniformis, PL XYII., Pig. 16. (Area pectun- 
culus, L.) 

jS/ieZZ orbicular, nearly equilateral, smooth or radiatcly striated; 
umbones central, divided by a striated ligamental area ; hingo 



426 MANUAL OF THE MOLLUSCA. 

witli a semicircular row of transverse teeth; adductors sub- 
equal ; pallial line simple ; margins crenated inside. 

Animal with a large crescent-shaped foot, margins of the 
sole undulated ; mantle open, margins simple, with minute 
ocelli ; gills equal, lips continuous with the gills. 

Distribution, 58 species. West Indies, Britain, India, ISTew 
Zealand, West America; ranging from 8 to 60, rarely 120 
fathoms. 

Fossil, 80 species. IsTeocomian — . United States, Europe 
South India. 

The teeth of Pedunculus and Area increase in number with 
age, by additions to each end of the hinge -line, but sometimes 
the central teeth are obliterated by encroachments of the liga- 
ment. 

LiMOPSis, Sassi, 1827. 

Type, L. aurita, PI. XYII., Fig. 17. 

Synonym, Trigonocoelia, Nyst. Pectunculina, D'Orb. 

Shell orbicular, convex, slightly oblique ; ligamental area 
with a triangular cartilage-pit in the centre ; hinge with 2 
equal, curved series of transverse teeth. 

Distribution, 4 species. Eed Sea (Nyst.), Japan, Britain. 
Mr. M'Andrew has dredged L. pygmcea, living, on the coast 
of Finmark; it is a fossil of the Pliocene of England, Belgium, 
and Sicily. 

Fossil, 36 species. Bath-oolite — . United States Europe- 

NiJCTJLA, Lam. 

Etymology, diminutive of nux, a nut. 

Example, N. Cobboldise, PI. XVII,, Fig. 18 

Shell trigonal, with the umbones turned towards the short 
posterior side ; smooth or sculptured, epidermis olive, interior 
pearly, margins crenulated ; hinge with prominent internal 
cartilage-pit, and a series of sharp teeth on each side ; pallial 
line simple. 

Animal with the mantle open, its margins plain ; foot large, 
deeply fissured in front, forming when expanded a disk with 
serrated margins ; mouth and lips minute, palpi very large, 
rounded, strongly plaited inside and furnished with a long con- 
voluted appendage ; gills small, plume-like, united behind the 
foot to the branchial septum. 

The Nucula uses its foot for burrowing, and Professor Forbes, 
has seen it creep up the side of a glass of sea-water. The labial/ 
appendages protrude from the shell at the same time with the 



COKCHIFEEl. 427 

foot. N. miralilis, Adams, from Japan, is sculptured like the 
extinct N. Cohholdice. 

Distribution, 70 species. United States, Norway, Cape, 
Japan, Sitka, Ckili. On coarse bottoms, from 5 — 100 fathoms. 

Fossil, 177 species. Lower Silurian ? — . Trias — . America, 
Europe, India. 

Sub-genera. Nuculina, D'Orb.* 1847. N. miliaris, PL XYII., 
Pig. 19. Shell minute ; teeth few, in one series, with a posterior 
lateral tooth. Eocene, Erance. Nucinella (ovalis), Searles- 
Wood, 1850 (=Pleurodon, Wood, 1840), a minute shell from 
the Coralline crag of Suffolk, is described as having an external 
ligament. 

? Stalagmium (margaritaceum), Conrad, 1833=Myoparo cos- 
tatus," Lea. Eocene, Alabama. ? S.Nystii, Galeotti (Nucunella, 
D'Orb.). Eocene, Belgium. Shell like Limojpsis ; ligamental 
area narrow, wholly posterior. 

IsoARCA, Miinster, 1842. 

Type, I. subspirata, M. Oxford Clay, France, Germany. 

Syiionym, Noetia, Gray. 

Shell ventricose ; beaks large, anterior, often sub -spiral; 
ligament entirely external ; hinge -line curved, with two series 
of transverse teeth, smallest in the centre ; pallial line simple. 

/. Logani (Ctecodonta), Salter, Lower Silurian, Canada, is 
3 inches long, and has the ligament preserved. 

Fossil, 14 species. Lower Silurian — Chalk. North America. 
Europe. 

Sub-genera. Cucullella, M'Coy. C. antiqua, Sby. Upper 
Silurian, Herefordshire. Shell elliptical, with a strong rib 
behind the anterior adductor impression. 

Limularca, Gray. Part anterior to the umbo toothless, with 
a lunule. 

L'EDA, Schumacher. 

Etymology, Leda, in Greek mythology, mother of Castor and 
Pollux. 

Synonym, Lembulus (Leach) PJsso. 

Example, L. caudata, PI. XVII., Eig. 20. 

Shell resembling Nucula ; oblong, rounded in front, pi'oiuced 
and pointed behind ; margins even ; pallial line with a snail 
sinus ; umbonal area with a linear impression joining the aite- 
rior adductor. 

Animal furnished with two partially-united, slender, unequ il, 

* N. donaciformis, Parreyss, from the White Nile, is a crustacean ! ;Estheria.) 



428 



MANUAL OF THE MOLLUSC A. 



siphonal tubes (Forbes) ; gills narrow, plume-like, deeply 
laminated, attached tbrougbout ; mantle-margin with small 
ventral lobes forming by their apposition a third siphon. 

Distribution, 80 species. Northern and Arctic Seas, 10— 
180 fathoms. Siberia, Melville Island, Massachusetts, Britain, 
Mediterranean, Cape, Japan, Australia. 

Fossil, 190 species. United States, Europe, South India. 
- Sub-genus, Yoldia, Moller (dedicated to the Countess Yoldi). 




Fig. 219. I'oMk n. sp. -I". Antarctic Expedition. 

(From a drawing by Albany Hancock, Esq.) The internal organs are represented, 
as seen through the mantle, on the removal of the right valve. 

a, a, adductors ; p, p, pedal muscles ; I, ligament ; g, gills ; s, siphons (much con- 
tracted) ; t, c, labial palpi and appendages ; i, intestine ; /, foot ; x, x, lateral muscles of 
the foot ; to, pallial luie. 

Y. myalis, PL XYII., Fig. 21. Shell oblong, slightly attenuated 
behind, compressed, smooth or obliquely sculptured, with dark 
olive shining epidermis ; external ligament slight ; cartilage as 
in Leda ; pallial sinus deep. Animal with the branchial and 
anal siphons united, retractile ; palpi very large, appendiculate ; 
gills narrow, posterior ; foot slightly heeled, deeply grooved, 
its margins crenulated ; intestine lying partly close to the right 
side of the body, and producing an impression in the shell ; 
mantle-margin plain in front, fringed behind ; destitute of 
ventral lobes. Distribution, Arctic and Antarctic Seas, Green- 
land, Massachusetts, Brazil, Norway, Kamtschatka. Yoldia 
limatula (Fig. 220) has been dredged, alive, by Mr. M'Andrew, 
on the coast of Finmark. It is also found in Portland Harbour, 
Massachusetts. The animal is very active, and leaps to an 
astonishing height, exceeding in this faculty the scollop-shells. 



CONCHIFEEA. 429 

(Dr. Migliels.) Fossil, Pliocene — . (Crag and Glacial deposits.) 
England, Belgium. 



Fig. 220. Yoldia limatula (after Barrett). 

SoLEiSTELLA, Sowerby. 

Type^ S. Norrisii, PL XYIL, Pig. 22. S. ornata, Pig. 23. 

Synonyms, Malletia, Desm. Ctenoconcha, Gray. Neilo, 
Adams. 

Shell oval, or ark-shaped, compressed, smooth or concentri- 
cally furrowed, epidermis olive ; ligament external, elongated, 
prominent : hinge with an anterior and posterior series of fino 
sharp teeth ; interior sub-nacreous ; pallial sinus large and 
deep ; anterior adductor giving off a long oblique pedal line. 

Animal like Yoldia; mantle-margins slightly fringed and 
furnished with ventral lobes ; siphonai tubes united, long, and 
slender, completely retractile ; palpi appendiculated, convoluted, 
as long as the shell ; gills narrow, posterior ; foot deeply cleft ; 
forming an oval disk, even-margined and striated across. 

Distribution, 2 species. Yalparaiso, New Zealand (shell like 
S. ornata). 

Fossil, 1 species. Miocene. Point Desire, Patagonia. 

? SoLEMYA, Lamarck. 

Tijpe, S. togata, PL XXII. , Pig. 17. 

Synonym, Solenomya, Menke. 

Shell elongated, cylindrical, gaping at each end; epidermis 
dark, horny, extending beyond the margins ; umbones poste- 
rior ; hinge edentulous ; ligament concealed ; pallial line 
obscure. Outer layer of long prismatic cells, nearly parallel 
with the surface, and mingled with dark cells, as in Pinna ; 
inner layer also cellular. 

Animal with the mantle lobes united behind, with a single 
siphonai orifice, hour-glass shape, and cirrated ; foot probos- 
cidiform, truncated and fringed at the end ; gills forming a 
single plume on each side, with the laminse free to the base ; 
palpi long and narrow, nearly free. 



430 



MANUAl OF THE MOLLTTSCA. 



Tlie shell resembles Glycimeris in the shortness of its posterior 
side, and the extraordinary development of its epidermis ; the 
animal most resembles Leda in the structure of its foot and 
gill's. 

Distribution, 4 species. United States, Canaries, West Africa 
(Gaboon Eiver), Mediterranean, Australia, New Zealand. 
Burrowing in mud ; 2 fathoms. 

Fossil, 4 species. Carb. — . Britain, Belgium. 



Pamily V. — Trigoniad^. 

Shdl equivalve, close, trigonal, with the umbones directed 
posteriorly ; ligament external ; interior nacreous ; hinge-teeth 
few, diverging ; pallial line simple. 

Animal with the mantle open ; foot long and bent ; gills two 
on each side, recumbent ; palpi simple. 

Trigonia, Bruguiere (not Aublet)* 

Etymology, Trigonos, three-angled. 
Synonym, Lyriodon, G. Sowerby. 

Example, T. Costata, PL XYII., Pig. 24. T. pectinata, Pig. 
221. 

Shell thick, tuberculated, or ornamented with radiating or 

concentric ribs ; posterior side 
angular; ligament small and 
prominent ; hinge-teeth 2.3, 
diverging, transversely stri- 
ated ; centre tooth of left valve 
divided ; pedal impressions in 
front of the posterior adductor, 
and one in the umbo of the 
left valve ; anterior adductor 
impression close to the umbo. 
Animal with a long and 
pointed foot, bent sharply, heel 
promitient, sole bordered by two crenulated ridges ; palpi small 
and pointed ; gills ample, the outer smallest, united behind the 
body to each other and to the mantle. 

The shell of Trigonia is almost entirely nacreous, and usually 
wanting or metamorphic in limestone strata ; casts of the in- 




Fig. 221. Trigonia pectinata.* 



* Fig. 221. From a specimen in alcohol ; the gills slightly curled and contracted, 
tliey should terminate near the margin, between the arrows which indicate the inhalent 
and exhalent currents : a, a', adductors ; h I, ligament ; t, t', dental sockets ; o, mouth ; 
1 1, labial tentacles or palpi ; p, pallial line ; m, margin ; /, foot ; v, cloaca. 



COJ«CHlFERA. 431 

terior are called " liorse -heads " by the Portland qtlarry-men;* 
they spoil the stone. Silicified casts have been found at Tiabury, 
in which the animal itself, with its gills, was preserved, f The 
species with the posterior angle of the shell elongated, have a 
siphonal ridge inside. The epidermal layer of the recent shell 
consists of nucleated cells, forming a beautiful microscopic 
object. A Trigonia placed by Mr. S. Stutchbury on the gunwale 
of his boat leapt overboard, clearing a ledge of four inches ; they 
are supposed to be migratory, as dredging for them is very 
uncertain, though they abound in some parts of Sydney Harbour. 

Distribution, 3 species (or varieties ?), Australia. 

Fossil, 100 species. Trias — Chalk (not known in Ter- 
tiaries). Europe, United States, Chili, Algeria, Cape, South 
India. 

MyoPhoeia, Bronn, 1830. 

Type, M. vulgaris, Schl. 

Synonym, Cryptina (Kefersteinii), Boue, 

Shell trigonal, umbones turned forwards ; obliquely keeled ; 
smooth or sculptured; teeth 2.3, striated obscurely, centre 
tooth of left valve simple, anterior of right valve prominent ; 
mould like Trigonia. M. decussata, PI. XYII., Pig. 25, has 
a lateral tooth at the dorsal angle of the left valve* 

Fossil, 16 species. Trias : Germany, Tyrol. 

Axmus, Sowerby, 1821. 

Type, A. obscurus, Sowerby. 

Synonym, Schizodus, King (not Waterhouse). 

Shell trigonal, rounded in front, attenuated behind ; rather 
thin, smooth, with an obscure oblique ridge ; ligament external ; 
hinge-teeth 2.3, smooth, rather small ; anterior adductor 
slightly impressed, removed from the hinge, with a pedal scar 
close to it ; pallial line simple. 

Fossil, 20 species. Upper Silurian — Muschelkalk. United 
States, Europe. Mactra trigonia, Goldf. Isocardia axiniformis. 
Ph. Anatina attenuata and Dolahra securiformis, M'Coy, pro- 
bably belong to this genus. Dolahra equilateralis, Amphidesma 
subtruncatum, with many others from the Palaeozoic rocks, may 
constitute a distinct genus, but their generic character has yet 
to be discovered. 

CtJETONOTtrs. Salter. 
Thickened hinge-plate, with a single strong triangular central 

* See Plott's Oxfordshire, T. vii. Kg. 1. 

X In the collection of the late Miss Benett of Warminstel', now in PlnladelpMa. 



432 MANUAL OP THE MOLLUSCA. 

tooth on each, valve. Eight valve plate with an ohscure tooth 
behind the central one. Anterior muscular scar deep ; pallial 
impression entire. 

Fossil, 6 species. Devonian, Britain. 

Pseud AXiNTJS, Salter. 

Tyjpe, P. (Anodontopsis) securiformis, M'Coy, and P. trigonus. 
Shell thin, edentulous, convex with prominent umbones, and 
a strong posterior carinated edge ; beaks anterior ; no lunette. 

Lyeodesma, Conrad, 1841. 

Type, L. plana, New York. 

Synonym, Actinodonta, Phil. 

Shell trigonia-shaped, rather elongated, with a striated pos- 
terior area ; hinge with several (5 — 9) radiating teeth, striated 
across ; ligament external. 

Fossil, 4 species. Lower Silurian : Canada, United States, 
Britain. 

Family YI. — IlNioisriD.^. Naides. 

Shell usually regular, equivalve, closed ; structure nacreous, 
with a very thin prismatic- cellular layer beneath the epidermis ; 
epidermis thick and dark; ligament external, large and pro- 
minent ; margins even ; anterior hinge-teeth thick and striated, 
posterior laminar, sometimes wanting ; adductor scars deeply 
impressed; pedal scars three, distinct, two behind the anterior 
adductor, one in front of the posterior. 

Animal with the manile-margins united between the siphonal 
orifices, and, rarely, in front of the branchial opening ; anal 
orifice plain, branchial fringed ; foot very large, tongue-shaped, 
compressed, byssiferous in the fry ; gills elongated, sub-equal, 
united posteriorly to each other and to the mantle, but not to 
the body; palpi moderate, laterally attached, striated inside; 
lips plain. Sexes distinct. 

The river mussels are found in the ponds and streams of all parts 
of the world. In Europe the species are few, though specimens 
are abundant ; in North America both species and individuals 
abound. All the remarkable generic forms are peculiar to 
South America and Africa. Two of these are fixed, and irre- 
gular when adult, and have been placed with the chamas and 
oysters by the admii'ers of artificial systems ; fortunately, how- 
ever, M. D'Orbigny has ascertained that the Mulleria, which 



COITCHIFEEA. 433 

is fixed and mono-myafy wlieii adult, is locomotive and di-myaiy 
when young ! * 

Like other fresh-water shells, the naids are often extensively 
eroded by the carbonic acid dissolved in the water they inhabit 
(p. 31). f This condition of the umbones is conspicuous in the 
great fossil Uniones of the Wealden, but cannot be detected in the 
Cardinice, and some other fossils formerly referred to this family. 

The outer gills of the female ujiionidse are filled with spawn 
in the winter and early spring ; the fry spins a delicate, ravelled 
byssus, and fiaps its triangular valves with the posterior shell- 
muscle, which is largely developed, whilst the other is yet 
inconspicuous. The shells of the female river-mussels are rather 
shorter and more ventricose than the others. 

TJjsrio, Eetz. Eiver-mussel. 

Etymology, unio, a pearl (Pliny). 

Example, U. Htoralis, PI. XYIII., Fig. 1. 

Shell oval or elongated, smooth, corrugated, or spiny, becom- 
ing very solid with age; anterior teeth 1.2, or 2.2, short, irre- 
gular; posterior teeth 1.2, elongated, laminar. 

Animal with the mantle-margins only united between the 
siphonal openings ; palpi long, pointed, laterally attached. 
(Fig. 209, p. 399.) 

U. plicafus (Symphynota, Sw. Dipsas, Leach) has the valves 
produced into a thin, elastic dorsal wing, as in Hyria.X In 
the Pearl-mussel, U. Margaritiferus (Margaritana, Schum. 
Alasmodon, Say, Baphia, Meusch.), the posterior teeth become 
obsolete with age. This species, which afforded the once famous 
British pearls, is found in the mountain streams of Britain, 
Lapland, and Canada : it is used for bait in the Aberdeen Cod- 
fishery. The Scotch pearl-fishery continued till the end of the 
last century, especially in the river Tay, where the mussels 
were collected by the peasantry before harvest time. The pearls 

* In the synopsis at p. 406, it will be seen that each of the principal groups of bi- 
valves contains members which are fixed and irregular, and others which are byssi- 
ferous, or burrowing, or locomotive. 

t Probably many of the organic acids, produced by the decay of vegetable matter, 
assist in the process. It has been suggested that sulphui'ic acid may sometimes be set 
free in river-water, by the decomposition of iron pyrites in the banks ; but Pjof. Boye 
of Philadelphia, states that it has not been detected in any river of the United states 
where the phenomenon of erosion is most notorious. 

t This is the species in which the Chinese produce artificial pearls by the introduc- 
tion of shot, &c., between the mantle of the animal and its sheU (p. 38) ; Llr. Gask in 
has an example containing two strings of pearls, and another in the Brit. Miis. has a 
nmnber of little josses made of beU-metal, now completely coated wth pearl, in its 
interior. 

U 



434 MANUAL OF THE MOLLUSCA. 

were nsnally found in old and deformed specimens ; round 
pearls about the size of a pea, peifect in every respect, were 
worth £3 or £4. (Dr. Knapp.) An account of the Irish pearl- 
fishery was given by Sir E. Bedding, in the Phil. Trans., 1693. 
The mussels were found set up in the sand of the river-beds with 
their open side turned from the torrent ; about one in a hundred 
might contain a pearl, and one pearl in a hundred might be 
tolerably clear. (See p. 30). 

Distribution, 420 species. North America, South America, 
Europe, Africa, Asia, Australia. 

Fossil, 50 species. Wealden — . Europe, India. 

Suh-genera, Monocondyloea, D'Orbigny. M. Paraguayana, 
PL XVIII. , Eig. 2. 

Shell with a single large, round, obtuse cardinal tooth in each 
valve ; no lateral teeth. 

Distribution, 6 species. South America. 

Hyria, Lam. H. syrmatophora, PL XVIII. , Eig. 3. Synonyms^ 
Pachyodon and Prisodon, Schum. Shell Area-shaped, hinge-line 
straight, with a dorsal wing on the posterior side ; teeth elon- 
gated, transversely striated. Distribution, 4 species. S. America. 

Cast ALIA, Lamarck. 

Type, C. ambigua, PL XVIII. , Eig. 4. 

Synonym, Tetraplodon, Spix. 

Shell ventricose ; trigonal ; umbones prominent, furrowed ; 
hinge- teeth striated; anterior 2.1, short; posterior 1.2, elon- 
gated. 

Animal with mantle-lobes united behind, forming two distinct 
siphonal orifices, the branchial cirrated. 

Distribution, 3 species. Eivers of South America, Q-uiana, 
Brazil. 

Anodon, Cuvier. Swan-mussel. 

Type, A. cygneus, Eig. 208, p. 398. 

Etymology f anodontos, edentulous. 

Shell like unio, but edentulous ; oval, smooth, rather thin, 
compressed when young, becoming ventricose with age. 

Animal like unio : the outer gills of a female have been com- 
puted to contain 300,000 young shells. (Lea.) See p. 14. _ 

Distribution, 100 species. North America, Europe, Siberia. 

Fossil, 8 species. Eocene — . Europe. 

M. D'Orbigny relates that he found great quantities of small 
Anodons [Bysso-anodonta Faraniensis, D'Orbigny) 4 lines in 
length, attached by a byssus, in the Eiver Parana, above 
Corrientes. 



CON"CHIFEEA. 435 

Ieedina, Lamarck. 

Synonyms, Mutela, Scop. Spatha, Ltea (including My cef opus). 
Leila, Gray. 

Type, I. exotica, PI. XVIIL, Pig. 5. 

Etymology, iris, tlie rainbow. 

Shell oblong ; umbones depressed ; binge-line long, straight, 
attenuated towards the umbones, crenated by numerous unequal 
teeth ; ligament long and narrow. 

Animal with mantle-lobes united posteriorly, forming two 
short siphons ; mouth and lips small ; palpi immense, oval ; gills 
united to the body. 

Jridina ovata (Pleiodon, Conrad) has a broader hinge-line. 

Distribution, 9 species. Pivers of Africa, Nile, Senegal. 

Mycetoptjs, D'Orbigny. 

Etymology, muTces, a mushroom, pous, the foot. 

Type, M. soleniformis, PI. XYIIL, Pig. 6. 

Shell elongated, sub -cylindrical, gaping in front ; margins 
sub -parallel, hinge edentulous. 

Animal with, an elongated, cylindrical foot, expanded into a 
disk at the end ; mantle open ; gills equal ; palpi short. 

Distribution, 3 species. Eiver Parana, Corrientes ; E.iver 
Amazon, Bolivia. 

^THEBIA, Lamarck. 

Type, ^. semilunata, PI. XYIIL, Pig. 7. {Aitherios, aerial.) 

Shell irregular, inequi valve ; attached by the umbo, and 
tubular processes of one of the valves, usually the left ; epidermis 
thick, olive; interior pearly, blistered (as if with air-bubbles) ; 
Mnge edentulous ; ligament external, with a conspicuous area 
and groove in the fixed valve ; two adductor impressions, the 
anterior very long and irregular ; pallial line simple. 

Animal with the mantle-lobes open ; body large, oblong, pro- 
jecting backwards ; no trace of a foot ; palpi large, semi-oval ; 
gills sub-equal, plaited, united posteriorly, and to the body and 
mantle. 

Distribution, 4 species. Piver Nile, from first cataracts to 
Fazool ; * Eiver Senegal. 

MuLLERiA, Perussac. 

Dedicated to Otto Prid. Miiller, author of the " Zoologia 
Danica." 

Type, M. lobata. Per., Pig. 222. 

Synonym, Acostsea (Guaduasana), D'Orbigny. 

* Tlie " fresh-water oysters " discovered by Bruce. 
U 2 



436 



MANUAL OF THE MOLLrSCA. 



Shell when young free, equivalve, Anodon-sliaped, -witli a long 
and prominent ligament, and two adductor impressions ; adult 
irregular, inequivalve, attached by the right valve ; umbones 
elongated, progressively filled up with shell, and forming an 
iiTegular " talon " in front of the fixed valve ; epidermis thick; 
ligament in a marginal groove ; interior pearly, muscular 




Fig. 222. Mulleria lobata, Fer. (Originals) 

impressions single, posterior. Pig. 222 represents the left, or 
attached A^alve, showing the single muscular impression, and 
projecting spur with the nucleus, consisting of Jo^/i valves of the 
fry, united, and filled up with shell.* 

Distribution, Eiver Magdalena, near Bogota, Net?" Granada. 

Mr. Isaac Lea has determined the identity of Miilleria and 
Acostoea by examination of Ferussac's type, and the suite of 
specimens, of different ages, in the collection of M. D'Orbigny.f 

Section B. — Siphonida. 

Animal with respiratory siphons ; mantle-lobes more or less 
united. 

a. Siphons short, pallial line simple; Integro-pallialia. 

* M. D'brbigny very liberally placed his suite of specimens of this remarkable 
genus in the British Museum. Oct., 1854. 

t The only specimen of Miilleria in England, prior to the acquisition of the D'Orbigny 
collection, was purchased many years ago by Mr. Thomas Norris of Bury, for £20. 



COITCHrFERA. 



437 



Family YII. — Chamid^. 

Shell inequivalve, thick, attaclied ; beaks sub.-spiral ; ligament 
external ; hinge-teeth 2 in one valve, 1 in the other ; adductor 
impressions large, reticulated ; pallial line simple. 

Animal with the mantle closed ; pedal and siphonal orifices 
small, sub-equal ; foot very small ; gills two on each side, very- 
unequal, united posteriorly. 

Chama (Pliny), L. 

Example, C. macrophylla, PI. XyilL, Pigs. 8, 9. 

Synonym, Aroinella, Schum. 

Shell attached usually by the left umbo ; 'valves foliaceous, the 
upper smallest ; hinge-tooth of free valve thick, curved, received 
between two teeth, in the other; adductor impressions large, 
oblong, the anterior encroaching on the hinge-tooth. 

Animal with the mantle-margins united by a curtain, witl^ 
two rows of tentacular filaments ; siphonal orifices wide apart, 
branchial slightly prominent, fringed, anal with a simple valve ; 
foot bent, or heeled ; liver occuj)ying the umbo of the attached 
valve only ; ovary extending into both mantle-lobes, as far as 




Fig. 223. Right side. Fig. 224. Left side. 

Fig. 223. Eight side, ss^th the umbonal portion of the mantle removed. 
Fig. 224. Left side, showing the relative extent of the liver and ovarium. 
a, a, adductors ; m, pallial line ; e, excurrent orifice ; b, branchial ; /, foot and 
pedal orifice ; p, posterior p^dal muscle ; t, palpi ; g, gills (contracted) ; I, liver ; o, 
ovarium ; d, dental lobes. 

the pallial line ; lips simple, palpi small and curled ; gills deeply 
plaited, the outer pair much shorter and very narrow, furnished 
with a free dorsal border, and united behind to each other, and 
to the mantle ; adductors each composed of two elements. 



438 



MAISTFAL OF THE MOLLUSCA. 



The shell of Chama consists of three layers ; the external, 
coloured layer is laminated by oblique lines of growth, with cop- 
■rngations at right angles to the laminae ; the foliaceous spines 
contain reticulated tubuli ; the middle layer is opaque white, 
and consists of ill-defined vertical prisms or corrugated struc- 
ture ; the inner layer, which is translucent and membranous, 
is penetrated by scattered vertical tubuli; the minute processes 
that occupy the tubuli give to the mantle (and to the casts of the 
shell) a granular appearance (Fig. 224, I, m). 

Some Chamas are attached indifferently by either valve ; when 
fixed by the right valve the dentition is reversed, the left valve 
having the single tooth. Ghama arcinella, which is always 
attached by the right umbo, has the normal dentition 1:2; it 
is nearly regular and equivalve, and has a distinct lunule. 

Distribution, 50 species. Tropical seas, especially amongst 
coral reefs; — 50 fathoms. West Indies, Canaries, Mediterranean, 
India, China. 

Fossil, 40 species. Green-sand — . United States, Europe. 

Sub-genus? Monopleura ; Matheron (= Dipilidia, Math.). 
M. imbricafa, Math. Eig. 226. Neocomian, Southern France. 




Fig. 225. Bi-radiolites, -|- Fig 226. Monopleura, -|-. 

p, point of attachment ; I, ligamental groove ; a, a, corresponding areas. 

Shell attached by the dextral umbo ; valves alike in structure 
and sculpturing ; fived valve straight, inversely conical, with a 
long, straight ligamental groove, and obscure hinge-area ; oper- 
cular valve flat or convex, with an oblique, sub-marginal umbo. 
Fossil, 10 species. Neocomian — Chalk. France, Texas. They 
are commonly found in grpups, adhering laterally, or rising one 
above the other ; the casts of such as are known are quite simple 
3,nd chama-like.. 



CONCHIPEEA. 

DiCEEAS, Lamarck. 



439 



Ttjpe, D. arietinum, PI. XVIII., Figs. 10 and 11, and Figs. 
227 and 228. 

Shell sub-equivalve, attached by either umbo ; beaks very- 
prominent, spiral, furrowed externally by ligamental grooves; 
hinge very thick, teeth 2.1, prominent; muscular impressions 
bounded by long spiral ridges, sometimes obsolete. 

Distribution, 5 species. Middle oolite. Grermany, Switzer- 
land, France, Algeria. 

Diceras differs from Chama in the great prominence of both 
its umbones, in having constantly two hinge-teeth in the right 




Fig. 227. Diceras arietinum, f, Fig. 228. Requienia ammonia, J. 

a, point of attachment ; /, I, ligamental grooves ; t, posterior adductor inflection. 

valve and one in the left, and in the prominent ridges bordering 
the muscular impressions. Similar ridges exist in CucuUcsa, 
Megalodon, Cardilia, and the Hippurite ; they produce deep 
spiral furrows on the casts, which are of common occurrence in 
the Coral-oolite of the Alps. One or both the anterior furrows 
(Fig. 229, t, t) are frequently obsolete. The dental pits are 
much deeper than the teeth which they receive, and are sub- 
spiral, giving rise to bifid projections (c, c) on the casts ; the 
single tooth in the left valve consists of two elements, and the 
cavity [fosset) which receives it is divided at the bottom. 

EEQUiEisriA, Matheron, 

Dedicated to M. Eequien, author of a Catalogue of Corsican 
MoUusca. 

Example, E. Lonsdalii, PI. XYIII., Fig. 12 and Fig. 230. 
E. ammonia, Fig. 189. 

Shell thick, very inequivalve, attached by the left umbo ; liga- 
ment external ; teeth 2:1; left valve spiral, its cavity deep, 



440 



MAinJAL OF THE MOLLTTSCA. 



not camerated ; free valve smaller, sub- spiral ; posterior ad- 
ductor bordered by a prominent sub-spiral ridge in each, valve. 

The shell structure of Eequienia is like that of Cliama. The 
relative size of the valves is subject to much variation ; in R. 




Fig. 229. Diceras, |. Fig. 230. Eequienia, f 

Internal casts ; a, point of attachment ; c, c\ casts of dental pits ; t, t', furrows 

produced by spiral ridges. (Mus. Brit. ) 

Ji^avn'(Sharpe) they are nearly equal. The hinge-teeth are like 
those of Diceras ; the cavity for the posterior tooth of the right 
valve is very deep and sub-spiral (Fig. 230, c'). The internal 
muscular ridges are produced by duplicatures of the shell-wall, 
and are indicated outside by grooves (Fig. 229, t'). In R. sub- 
(squalis and Toucasiana there is a second parallel ridge, as in 
Hippurites and Caprotina. 

Fossil, 7 species. Neocomian — L. Chalk. Britain, France, 
Spain, Algeria, Texas. 

Family YIII. — ^Hippubitid^. 
(Order Rudistes, Lamarck.) 

Shell inequivalve, unsymmetrical, thick, attached by the 
right umbo ; umbones frequently camerated ; structure and 
sculpturing of valves dissimilar ; ligament internal ; hinge-teeth 
1:2; adductor impressions 2, large, those of the left valve on 
prominent apophyses ; pallial line simple, sub-marginal. 

The shells of this extinct family are characteristic of the 
cretaceous strata, and abound in many parts of the Peninsula, 
the Alps, and Eastern Europe, where the equivalent of the 
Lower Chalk has received the name of "Hippurite limestone." 
They occur also in Turkey and in Egypt, and Dr. F. Eoemerhas 
found them in Texas and Guadaloupe. The structure of these 
shells has been fully described in the Quarterly Journal of the 



coifcati'iiRA; 441 

d^eoioglcal Sociefy of London. In all the genera the shell con- 
sists of three layers^ but the outermost, which is thin and com- 
pact, is often destroyed by the weathering of the specimens. 
The principal layer in the lower valve of the Hippurite is not 
really very different from the upper valve in structure; the 
laminse are corrugated, leaving irregular pores, or tubes, parallel 
■with the long a^is of the shell, and often visible on the rim. 
The umbo of the upper valve of the Radiolite is marginal in the 
young shell. (Q. J. Geol. Soc, vol. xi. p. 40.) 

They are the most problematic of all fossils ; there are no 
recent shells which can be supposed to belong to the same 
family ; and the condition in which they usually occur has in- 
volved them in greater obscurity.* The characters which 
determine their position amongst the ordinary bivalves are the 
following :— 

1. The shell is composed of three distinct layers. 

2. They are essentially unsymmetrical, and right-and-left 
Valved. 

3. The sculpturing of the valves is dissimilar. 

4. There is evidence of a large internal ligament. 

o. The hinge-teeth are developed from the free valve. 

6. The muscular impressions are 2 only. 

7. There is a distinct pallial line. 

The outer layer of shell in the Eadiolite consists of prismatic 
cellular structure (Fig. 232) ; the prisms are perpendicular to 
the shell-laminge, and often minutely subdivided* The cells 
appear to have been empty, like those of Ostrea (p. 40*7 ).t The 
inner layer, which forms the hinge and lines the umbones is 
sub-nacreous, and very rarely preserved. It is usually replaced 
by calcareous spar (Fig. 239), sometimes by mud or chalk, and 
Very often it is only indicated by a vacuity between the outer 
shell and the internal mould (Fig. 244). The inner shell-layer 

* 1. Bucli regarded them as Corals. 1840, Leonii. and Bronn Jahrb* p. .573. 

2. Desmoulins, as a combination of the Tiinicary and Sessile Cirripede. 

3. Dr. Carpenter, as a " group intermediate between the Conchifera and CirripedaJ''' 
An. Nat. Hist. XII. 390. 

4. Profv Steenstrup, of Coj^enhagen, as Annelids. 

6. Mr. D. Sharpe refers Hippurites to the Balani ; Caprindla to the Chamacese. 
• 6. La Peyrouse considered the Hippurites Orthocerata; the Radiolites, Ostfacea, 
1. G-oldfUss and D'Orbigny place them both with the Brackiopoda. 

8. Lamarck and Rang, between the Bfdthiopoda and Ostracece. 

9. Cuvier and Owen, with the Lamellibra.nchiate bivalves. 

10. Deshayes, in the same group with ^iheria. 

11. Quenstedt, between the Chamacea and Cardiacete.' 

t This is verj*- conspicuous in Radiolites from the chalk ; a formation in which otbef 
prisinatic-cellular fossils are sohd. 

V 3 



442 



MANtTAl, OF THE MOLttlSCA. 



is seldom compact, its lamellae are extremely thin, and separated 
by intervals like the water- chambers of Spondylus ; similar 
spaces occur in the deposit, filling the nmbonal cayity of the 
long-beaked oysters.* 

The inner layer ceases at the pallial line, beyond which, on 
the rim of the shell, the cellular structure is often apparent ; 




Fig, 231. Section of a fragment of Ostrea Carniccopice, 

obscure bifurcating impressions radiate from the pallial line to 
the outer margin (Fig. 232, v, v). 

These have been compared to the vascular impressions of 




Fig. 232. Part of the rim of Radiolites Mortoni, Mantell.f 

Crania (Figs. 193, 194), and constitute the only argument for 
supposing the Budistea to have been palliobranchiate ; but they 

* The water-chambers in some of the cylindrical Hippurites are large and regular, 
like those of the fossil corals Amplexus and Cyathophyllum. A section of Hippurites 
bi'oculatus passing tlirough only one of the dental sockets, resembles an Orthoceras 
vrith a lateral siphuncle ; whilst a Caprinella (Fig. 246), which has lost its outer layer, 
mi;.htbe mistaken for an Ammonite. 

t Traced from the original specimen in the Museiun of the School of Mines, b, is 
the inner edge ; a, the outer edge ; v, v, the dichotomous impressions ; the horizontal 
laminae are seen on the shaded side. Lower chalk ; Sussex. 



COKCHIFEKA. 443 

occur on the rim of the shell, and not on the disk, as in Crania.* 
The chief peculiarity of the HippuritidcB is the dissimilarity in 
the structure of the valves, but even this is deprived of much 
significance by its inconstancy, f The free valve of Rippurites 
is perforated by radiating canals which open round its inner 
margin, and communicate with the upper surface by numerous 
pores, as if to supply the interior with filtered water ; possibly 
they were closed by the epidermis4 

In the closely allied genus Eadiolites there is no trace of such 
canals, nor in Caprotina. Those which exist in the upper valve 
of Caprina, and in both valves of Caprinella, have no commu- 
nication with the outer surface of the shell ; they appear to be 
only of the same character with the tubular ribs of Cardium 
costatum (PL XIX,, Fig. 1), and it is highly improbable that 
they were permanently occupied by processes from the margin 
of the mantle. 

The teeth of the left, or upper valve, are so prominent and 
straight, that its movement must have been nearly vertical, 
for which purpose the internal ligament appears to hane been 
exactly suited by its position and magnitude , but it is probable 
that, , like other bivalves, they opened to a very small extent. 

HiPPimiTES, Lamarck- 

Name, adopted from old writers, '* fossil Hippuris,^' or 
Horse-tail. 

Types, H. hi-oculatus, Lamarck, and H. comu-vaccinum, 
Fig. 237. 

Shell very inequivalve, inversely conical, or elongated and 
cylindrical; Jixed valve atTiaiedi or smooth, with three parallel 
furrows {I, m, n) on th© cardinal side, indicating duplicatures 
of the outer shell layer; internal margin slightly plaited; pallial 
line continuous ; umbonal cavity moderately deep, ligamental 
inflection (Z) with a small cartilage-pit on each side (c, c) ; dental 
sockets sub-central, divided by an obsolete tooth; anterior 
muscular impression (a) elongated, double; posterior (a) 

* M. D'Orbigny considers they were produced by peculiar appendages to the 
mantle-margin, which, in Hippurites, were prolonged into the canals of the upper 
valve. 

t The lower valves of some Spondyli are squamous or spiny, the upper plain ; those 
of many oj'sters, Pectens, and some Tellens are diversely sculptured ; but in no instance 
is the internal structure of the two valves different. The inconstancy of the shell 
structure in the Mudistes has a parallel in Rhynchonella and Terebratula (p. 360), and 
in the condition of the hepatic organ in Tritonia and Dendronotus. 

% The valves of Crania are perforated by branching tubuii, but in that case they pass 
vertically Vaxouo^i every part of the shell, &vA all its layers (p. 361). 



444 



MAKTTAL OF THE MOLLtJSCA. 



small, very deep, boimded by tlie second duplicature (m) ; tMi-d 
duplicature {n) projecting into tlie iinibonal cavity : free valve 




Fig. 233. Interior of lower valve, |. 



Fig, 234. Upper valve (restored). 



Hippurites radiosus, Desm. Lower chalk, St. Mamest, Dordogne.* 
a, a, adductor impressions and processes ; c, c, cartUage pits ; t, t', teeth and dental 
sockets; m, umbonal cavity; p, orifices of canals; I, Ugamental inflection; m mus- 
cular, n siphon al inflection. 

depressed, witli a central umbo, and two grooves or pits cor^ 





Fig. 235. B. Toucasianus, upper valve, |,t Fig. 236. Lower valve, vpitii mould, | 
I Ugamental, m muscular, n siphonal inflections; x, fracture, showing canals) 

c, cartilage ; u, left umbo ; the arrows indicate the probable direction of the branchial 

cturents. 

responding to the posterior ridges in tlie lower valve ; surface 

* From the original in the Brit. Mus. The inner layer of shell in this species has an 
irregularly cellular structure, to which its preservation is due. 

t This internal mould, representing the form of the animal, was obtained by remov- 
ing the upper valve piecemeal with the chisel ; a plaster-cast taken from it represents 
the interior of the upper valve, with the bases of the teeth and apophyses. See origi- 
nals in Brit. Mus. 



COlfCatFEllA. 



445 



porous, tliG pores leading to canals in tlie outer shell-layer, 
■which open round the pallial line upon the inner margin ; 
anterior cartilage -pit deep and conical, posterior shallow ; 
umbonal cayity turned to the front {u) ; teeth 2, straight, sub- 
central, the anterior largest, each supporting a crooked muscular 
apophysis, the first broad, the hinder prominent, tooth-like ; 
inflections (m, n) surrounded by deep channels* 

H, cornu-vaccinum attains a length of more than a foot, and 
is curved like a cow's horn ; the outer layer separates readily 
from the core, which is furrowed longitudinally. The ligamental 
inflection (Z) is very deep and narrow, and the anterior tooth 
farther removed from the side than in H. hi-oculatus and radiosus 
(Figs. 233, 234) ; the posterior apophysis (a') does not nearly fill 
the corresponding cavity in the lower valve. In H. hi-oculatus 
and some other species there is no ligamental ridge inside j 
these, when they have lost their inner layer, present a cylin- 
drical cavity with two parallel ridges, extending down one side. 
The third inflection [n) is possibly a siphonal fold, such as exists 
in the tube of Teredo, and sometimes in the valves of Fliolas^ 
Clavagella, and the caudate species of Trigonia. 

The development of processes from the upper valve, for the 




-a 




Pig. 237. Longitudinal section ; upper half, f. Fig. 288. Transverse section, ^. 

Hippurites cornu-vaccinum, JBronn. Salzburg, 
I, m, n, duplicatures ; u, umbonal cavity of left Valve ; r, of right valve ; c, c', car- 
tilage-pits ; t, t', teeth ; a, a', muscular apophyses ; d, outer shell-layer. Fig. 237 is 
taken in the line d b of Fig. 238, cutting only the ba,se of the posterior tooth {t'). 
Fig. 238 is from a larger specimen, at about the level db of Fig. 237, cutting the point 
of the posterior apophysis (a'), and showing the peculiar sheU-texture deposited by 
the anterior adductor {a). 

attachment of the adductor muscles harmonises with Ihe other 
peculiarities of the Hippurite. The equal growth of the margins 



446 



MAKFAL OB THE MOILTJSCA. 



of the valves produces central umbones, and necessitates an 
internal cartilage ; this again causes the removal of the teeth 
and adductors farther from the hinge-margin, to a position in 
"which the muscles must have been unusually long, unless sup- 
ported in the manner described. Supposing the animal to have 
had a small foot, like ChawM, the mantle- opening for that organ 
would have been completely obstructed by the adductor, but 
that the muscular support was hook-shaped (Fig. 239, a). The 
posterior adductor-process is similarly under-cut for the passage 
of the rectum, which in all bivalves emerges between the hinge 




Fig. 239. Hippurites comu^vaccinum. Fig. 240. Hadiolites cylindraceus, f. 
Longitudinal sections taken through the teeth (f, V) and apophyses (a, a'). 

d outer, r inner shell-layer ; I, dental plate of lower valve ; u, umbonal cavity of upper 
valves ; i, intestinal channel. Originals in Brit, Mus. 

and posterior adductor, winds round outside that muscle, and 
terminates in the line'of the exhalent current. There is a groove 
(sometimes an inch deep) round the second and third duplica- 
tures in the upper valve, which seems intended to facilitate the 
passage of the alimentary canal, and the flow of water from the 
gills into the exhalent channel. The smallness of the space for 
the branchiae may have been compensated by deep plication of 
those organs, as in Chama and Tridacna. 

Fossil, 30 species. Chalk. Bohemia, Tyrol, Prance, Spain, 
Turkey, Syria, Algeria, Egypt. 

Eadiolites, Lamarck, 1801. 

Etymology, radius, a ray. 

Synonym, Sphserulites, De la Metherie, 1805. 

Shell inversely conical, bi-conic, or cylindrical ; valves dis- 
similar in structure ; internal margins smooth or finely striated, 
.simple, continuous ; ligamental inflection very narrow, dividins' 



CONCHIli'ERA. 



447 



tlie deep and rugose cartilage pits : loiuer valve with a thick outer 
layer, often foliaceous ; its cayity deep and straight, with two 





Fig, 241. Interior of lower valve. Fig. 242. Interior of tipper valve. 

JRadiolites mammillariSf Math. |. L, Chalk. S. Mamest, Dordogne. 

f', ligamental inilection; m, pallial Hne ; c, c, cartilage pits ; a, a, adductor impressionfi 

and processes ; t, teeth and'dental sockets. 

dental sockets and lateral muscular impressions; upper valve 
flat or conical, with a central umbo ; outer layer thin, radiated ; 





Fig. 243. Side views of the upper valve of E. mammillaris ; I, hgamental inflection 3 
t, teeth ; a, a', muscular processes. 

umhonal cayity inclined towards the, ligament ; teeth angular, 
striated, supporting, curved and sub-equal muscular processes. 

The upper yalye of E. fleuriausus has an oblique umbo, with 
a distinct ligamental groove. The* foliations of the lower valve 
are frequently undulated ; they are sometimes as thin as paper, 
and several inches wide. 

The umbonal cayity of the lower valve is partitioned off by 
very delicate fannel-shaped laminae. Specimens frequently 
occur in which the outer shell layer is preserved, whilst the 
inner is wanting, and the mould ("birostrites") remains loose 
\i the centre. The interior of the outer shell layer is deeply 



448 



MAl^tTAL OP THE MOLttTSCA. 



grooyed with lines of growth, and exhibits a distinct ligameatal 
ridge in each valve-. 

In aged examples of R. caUeoloides the ligamental inflection 
is concealed, the cartilage pits partially filled up and smoothed, 




JFig. 244. Upper view. Tig. 245. Side view. 

Internal mould of B. HcBninghausii', Desm.^ |. Chalk. 
% umbo of left valve ; r, right umbo ; Z, ligamental groove ; c, c, cartilage ; a, anterio|f 
adductor muscle ; a\ posterior. 

and the teeth and apophyses so firmly wedged into their re-* 
spective cavities, as to suggest the notion that the valves had 
become fixed about a quarter of an inch apart, and ceased to 
open and close at the will of the animal. 

Fossil, 42 species. Neocomian— -Chalk. Texas ^ Britain, 
France, Bohemia, Saxony, Portugalj Algeria, Egypt. 

Sub-genus ? Bi-radioUtes, D'Orbigny. E. canaliculatus 
(Fig. 225, upper valve). Ligamental groove visible in one or 
both valves, sometimes occupying the crest of a ridge, and 
bordered by two similar areas (a, a). Fossil, 5 species. Chalk, 
Prance. 



CAfRiN-ELLA, D'Otbigny. 

Type, C. triangularis, Desm. (Fig. 246). 

Synonym, Caprinula (Boissii), D'Orbigny* 

Shell fixed by the apex of the right valve, or free ,' composed 
of a thick layer of open tubes, with a thin compact superficial 
lamina ; cartilage internal, contained in several deep pits ; 
umbones more or less camerated ; right valve conical or elon- 
gated, with a ligamental furrow on its convex side, and furnished 
with one strong hinge-tooth supported by an oblique plate : left 



COlSrCHIFEEA. 449 

valve oblique or spiral, with, two hinge teeth, the anterior 




Fig. 246. Caprinella triangularis, Desm. U. Greensand, Eoclielle, ?-. 
A, portion of the left valve, after D'Orbigny,* tlie shell-wall is removed bj" -weather- 
ing, exposing the camerated interior. B, mould of five of the water-chambers. C, 
mould of the body- chamber ; u, umbo of right valve ; s, of left valve ; t, dental groove ; 
a, surface from which the posterior lobe has been detached. From, the originals in the 
Brit. Mus., presented by S. P. Pratt, Esq. 

supported by a plate which divides the lunbonal cavity length- 
wise. 
In Q. triangularis th.e unibonal cavity of the spiral valve is 




Fig. 247. Straight valve. Fig. 248. Spiral valve. 

Transverse sections of C Boissii, L. Chalk, Lisbon (Mr. Sharpe). 

I, position of ligamental inflection ; t, teeth ; c, cartilage pits ; w, umbonal cavity. 

Fig. 248 is from a weathered specimen, which has lost the outer laj^er. The tubes of 

the shell-wall are filled with limestone containing small shells. 

partitioned off at regular intervals (Fig. 246, A) ; the length of 

3^ inches, and of the body- 



the water chambers is sometimes 



* In M, D'Orbigny's figure the smaller valve has been added from another speci- 
men, and is turned towards the spire of the large valve, (Pal. Franc, pi. 542, fig. 
1). In Mr. ir-ratt's specimens, and those collected by Mr. Sharpe in Portugal, the 
umbo of tl;e smaller valve is turned away with a sigmoid flexure. (Q. J. G-eol. Soc 
VI. pi. 18.) 



450 



MAinJAL OF THE MOLLTJSCA. 



chamber from 2 to 7 diameters ; specunens measuring a yard 
across may be seen on the cavernous shores of the islets near 
Eochelle.* (Pratt.) 

Fossil, 6 species. Neocomian — Lower Chalk. France, Portugal, 
Texas, 





Fig. 249, C. Aguilloni, left valve. 



'Eig.2m,C.adversa (after D'Orb.). 



a, a, position of adductors ; I, ligament ; m, umbonal cavity ; t, tooth of fixed valve, 
broken off and remaining in its socket ; c, original point of attachment, 



Caprin-a, C. D'Orbigny. 

Etymology, caprina, pertaining to a goat. 

Synonym, Plagioptychus, Matheron. 

Type, 0. Aguilloni, C. D'Orbigny, Lower Chalk, Tyrol 
(= C. Partschii, Hauer). 

Shell with dissimilar valves, cartilage internal ; fixed valve 
conical, marked only by lines of growth and a ligamental 
groove ; hinge-margin with several deep cartilage-pits ; and one 
large and prominent tooth on the posterior side ; free valve 
oblique or spiral, thick, perforated by one or more rows of 
flattened canals, radiating from the umbo and opening around 
the inner margin ; anterior tooth supported by a plate which 
divides the umbonal cavity lengthwise, posterior tooth obscure ; 
hinge-margin much thickened, grooved for the cartilage. 

In C. adversa (Fig. 250) the free valve is (&) sinistraUy spiral ; 
its cavity is partitioned off by numerous septa, and divided 
longitudinally by the dental plate. When young it is attached 
by the apex of the straight valve (c), but afterwards becomes 
detached, as the large specimens are found imbedded with the 
spire downwards. (Saemann.) Thelower yqIyq oi C. Coquandiana 
is sub-spiral. 

* These singular fossils were called ichthyosarcolit^Si by Desmarest, from their 
resemblance to the flaky muscles of fishes, 



COlSrCHIFEEA. 



451 



Fossil, 10 species. XFpper Greensand and Lower Chalk. 
Bohemia, France, Texas. 




Fig, 251. Internal mould of Caprotina quadripartita, D'Orb., |. 
M,left umbo ; r, right umbo; I, ligamental inflection ; c, cartilage ; t, V, dental sockets 
a, a', position of adductors ; at e, a portion of the third lobe is broken away.* From a 
specimen collected by Mr, Pratt. 

Capeotina, D'Orbigny. 

Type, 0. semistriata, PI. XIX., Figs. 13 and 14. Le 'Mans, 
Sarthe. 

Shell composed of two distinct layers ; yalves alike in struc- 
ture, dissimilar in sculpturing ; ligamental groove slight ; 
cartilage internal ; right valve fixed, striated, or ribbed, with one 
narrow tooth between two deep pits, cartilage pits several on 
each side of the ligamental inflection, posterior adductor sup- 
ported by a plate : free valve flat or convex, with a marginal 
umbo ; teeth .2, very prominent, supported by ridges {apophyses) 
of the adductor muscles [a a'), the anterior tooth connected with 
a third plate {n), which divides the umbonal cavity. 

The smaller Caprotince occur in groups, attached to oyster- 
shells ; their muscular ridges are much less developed than m 
the large species (Fig. 251). C. costata is like a little Eadiolite. 

Fossil, 10 species. Upper Greensand, France. (The rest are 
Chamas, &c.) 

Family IX. — Tridacjiod^. 

Shell regular, equivalve, truncated in front ; ligament 
external ; valves strongly ribbed, margins toothed ; muscular 
impressions blended, sub-central, obscure. 

* The first and fourth lobes, those on each side of the ligamental infection, appear 
to be the two divisions of a great internal cartilage, like that of the Eadiolite. (Figs 
244, 245, c, c.) 



452 



MAiniAL OF THE MOLLUSC A. 



Animal attaciied by a byssus, or free ; mantle-lobe extensively 
united ; pedal opening large, anterior ; sipbonal orifices sur- 
rounded by a thickened pallial border ; branchial plain ; anal 
remote, with a tubular valve ; shell-muscle single, large and 
round, with a smaller pedal muscle close to it behind ; foot 
finger-like, with a byssal groove ; gills 2 on each side, narrow, 
strongly plaited, the outer pair composed of a single lamina, the 
inner thick, with margins conspicuously grooved ; palpi very 
slender, pointed. 

The shell of Tridacna is extremely hard, being calcified until 
almost every trace of organic structure is obliterated. (Car- 
penter.) 

TuiDACisrA, Bruguiere. Clam-shell. 

Etymology, tri, three, dakno, to bite; a kind of oyster. 
(Pliny.) 

Example, T. squamosa, PI. XYIII., Pig. 15. 

Shell massive, trigonal, ornamented with radiating ribs and 
imbricating foliations • margins deeply indented ; byssal sinus 




rig. -202. Tridacna Crocea-, Lam. ([Original.) 

a, the single adductor muscle ; p, pedal muscle, and pedal opening in mantle . 
y, tlie sndall grooved foot; 6, byssus: i, labial tentacles; g, gills; I, the broad pailial 
muscle ; between g and I is tlie renal organ ; m, tlie double mantle-margin ; s, the 
siphonal border; i, inhalent orifice; e, valvular excurrent orifice. An. Nat. Ilist. 
1855, p. 190. 

in each valve large, close to the umbo in front ; hinge teeth 
1.1, posterior laterals 2.1. 

A pair of valves of T. gigas, weighing upwards of 500 lbs. and 
raeasuring about 2 feet across, are used as benitiers in the Chuy-ch 



CONCHIFEEA. 453 

of St. Sulpice, Paris. (Dillwyn.; Captain Cook states that 
the animal of this species sometimes weighs 20 lbs. and is good 
eating. * 

Fig. 252 shows the animal of Tridacna, as seen on removing 
the left yalve and part of the mantle within the pallial line. 

Distribution, 7 species. Indian Ocean, China Seas, Pacific. 

Fossil, T. media. Miocene, Poland (Pusch). Tridacna and 
Hippojous are found in the raised coral-reefs of Torres Straits. 
(Macgillivray.) 

Sub-genus. jStpjpqpt^s, Lamarck. H. maciilatils, PI. XYIII., 
Fig. 16. The "bear's-paw clam "has close valves with two 
hinge-teeth in each. It is found on the reefs in the Coral Sea. 
The animal spins a small hyssus. 

Family X. — Cabdiad^. 

Shell regular, equiyalve, free, cordate, ornamented with 
radiating ribs ; posterior slope sculptured differently from the 
front and sides ; cardinal teeth two, laterals 1 . 1 in each valve ; 
ligament external^ short and prominent ; pallial line simple or 
slightly situated behind; muscular impressions sub-quadrate. 

Animal with mantle open in front; siphons usually very 
short, cirrated externally ; gills two on each side, thick, united 
posteriorly ; palpi narrow and pointed ; foot largCj sickle-shaped. 

Cahditjm, L. Cockle. 

Mymology, kardia, the heart. 

Synonym, Papyridea, Sw. 

Types, C. costatum, PL XIX., Fig. 1. C. lyratum. Fig, 2. 

Shell ventricose, close or gaping posteriorly ; umbones promi- 
nentj sub-central; margins crenulated; pallial line more or 
less sinuated. 

Animal with the mantle-margins plaited ; siphons clothed 
with tentacular filaments anal orifice with a tubular valve ; 
branchial fringed ; foot long, cylindrical, sickle-shaped, heeled. 

The cockle ( Q. edide) frequents sandy bays, near low water ; a 
small variety lives in the brackish waters of the river Thames, 
as high as Gravesend ; it ranges to the Baltic, and is found in 
the Black Sea and Caspian. C. rusticum extends from the Icy 
Sea to the Mediterranean, Black Sea, Caspian, and Aral. On 
the coast of Devon the large prickly cockle (C. aculeatum) is 
eaten. 

» "We stayed a long time in the lagoon (of Keeling Id.), examining the fields of 
coral and the gigantic clam-sheUs, into which if a man were to put his liand, he would 
not, as long as the animal lived, be able to withdraw it." (Darwin's Journal, p. 460.) 



461 



MANUAL OF THE MOLLITSCA. 



8uh-genera. Hemicardium (Cardissa) Cuyier. C. L.emicai'dium, 
PL XIX.. Fig. 3. Shell depressed, posterior slope flat, valves 
prominently keeled. 

Lithocardium aviculare, PL XVIII., Fig. 17. Shell triangular, 
keeled; anterior side very sliort; hinge-teeth 1.2, directed 
backwards ; posterior laterals 2.1; anterior muscular pit minute, 
posterior impression large, remote from the hinge. L. cymhulare, 
Lam,, exhibits slight indications of a byssal sinus in the front 
margins of the valves. Fossil, Eocene, France. These shells 
present considerable resemblance to Tridacna. 

Serrijpes (groenlandicus) Beck. Hinge edentulous. Arctic 
Seas, from 0. Parry to Sea of Kara ; fossil in the Norwich Crag. 




Fig. 253. C. IcEvmsculum, Eichw. (after Middendorff). 

Adacna, Eichwald. C. edentulum, PL XIX., Fig. 4. (Acardo, 
Sw. not Brug. Pholadomya, Ag. and Mid. not Sby.) Shell com- 
pressed, gaping behind, thin, nearly edentulous; pallial line 
sinuated. Animal with the foot (/) compressed; siphons (s) 
elongated, united nearly to the end, plain. Distrihution, 8 species. 
Aral, Caspian, Azof, Black Sea, and the embouchures of the 
Wolga, Dniester, Dnieper, and Don; burrowing in mud. (7. 
Caspicum (Monodacna, Eichw.) has a single hinge-tooth, and 
G. trigonoides (Didacna, E.) rudiments of two teeth. The 
siphonal inflection varies in amotint. 

Distribution, 200 species. World-wide ; from the sea-shore to 
140 fathoms. Gregarious on sands and sandy mud. 
' Fossil, 330 species. Upper Silurian — . Patagonia — 
Southern India. 

C. Hillanum, Sby. (Protocardium, Beyr.), is the type of a 
small group in which the sides are concentrically furrowed, the 
posterior slope radiately striated; the pallial line is slightly 
sinuated. Jura — Chalk ; Europe, India. 



Synonyms, Lychas, Stein, 
cardium, Miinster. 



CoNOCARDlXJM, Bronn. 

PleurorhynchuSj Ph. Lunulo- 



COJTCSirEEA. 455 

Type, C. HibemicTim, PL XIX., Pig. 5. C. aliforme, 
Pig. 254. 

Bhell, equivalve trigonal, conical and gaping infront, truncated 
behind, with a long siphonal tube near the umbones ; anterior 




Fig. 251. Conocardium aliforme, Shy^ Carb., Ireland. (Mus. Tennant.) 

slope radiately, posterior obliquely striated ; margins strongly 
crenulated within ; hinge with anterior and posterior laminar 
teeth ; ligament external. 

The truncated end has usually been considered anterior, a con- 
clusion which seems incompatible with the vertical position and 
burrowing habits of most free and equivalve shells ; if compared 
with Adacna (Pig. 253) the large gape (a) will be for the foot, 
and the long tube (s) siphonal. (7. Hihernicum has an expanded 
keel, like Hemicardium inversiim>. The shell-structure is pris- 
matic-cellular, as first pointed out by Sowerby ; but the cells 
are cubical, and much larger than in any of the Aviculadce. In 
Cardium the outer layer is only corrugated or obscurely pris- 
matic-cellular. 

Fossil f 30 species* U. Silurian — Carb. North America, 
Europe. 

Pamily XI. — LtrcEsriD^. 

Shell orbicular, free, closed; hinge-teeth 1 or 2, laterals 1 — ^1 
or obsolete ; interior dull, obliquely furrowed ; pallial line 
simple ; muscular impressions 2, elongated, rugose ; ligament 
inconspicuous or sub-internal. 

Animal with mantle-lobes open below, and having one or 
two siphonal orifices behind; foot elongated, cylindrical, or 
strap-shaped {ligulate), protruded at the base of the shell ; gills 
one (or two) on each side, large and thick, oval; mouth and 
palpi usually minute. 

The Lucinidis are distributed chiefly in the tropical and 
temperate seas, upon sandy and muddy bottoms, from the sea- 
shore to the greatest habitable depths. The shell consists of two 
distinct layers. 

Pig. 255 represents the animal of a species of Diplodonta, 



456 



MANUAL OF THE MOLLUSCA. 



from tlie Philippines, as seen on removing tlie left Taive, and 
part of the mantle within the pallial line ; h-c, the large pedal 

opening; the arrows indicate 
the small plain incurrent orifice, 
and the valvular excurrent ori- 
fice ; /, the foot, contracted in 
spirit ; p p, the large striated 
palpi ; I, the liver ; the outer 
gill has a simple margin, the 
inner is grooved and conducts 
to the mouth. This genus has 
higher claims than Kellia to be 
regarded as the type of a 
family. 




Fig. 255. Diplodonta. 



LucrN'A, Bruguiere. 

Etymology, Lucina, a name of Juno. 

Type, L. Pennsylvanica, PL XIX., Fig. 6. 

Shell orbicular, white ; umbones depressed ; lunule distinct ; 
margins smooth or minutely crenulated ; ligament oblique, 
semi-internal; hinge-teeth 2.2, laterals 1 — 1 and 2—2, or obso- 
lete ; muscular impressions rugose, anterior elongated within 
the pallial line, posterior oblong ; umbonal area with an oblique 
furrow. 

Animal with the mantle freely open below; siphonal orifices 
simple ; mouth minute, lips thin ; gills single on each side, very 
large and thick ; foot cylindrical, pointed, slightly heeled at the 
base. 

The foot of Lucina is often twice as long as the animal, but is 
usually folded back on itself and concealed between the gills ; 
it is hollow throughout. L. Zac^ea (Loripes, Poli.) has a long 
contractile anal tube. L. tigrina (Codakia, Scop.) has the liga- 
ment concealed between the valves, its lateral teeth are obsolete. 

Distribution, 10 species. West Indies, Norway, Black Sea, 
New Zealand; 120 fathoms. 

Fossil, 250 species. U. Silurian — . United States — T. del 
Fuego ; Europe — Southern India. 

Sub-genera, Gryptodon, Turton. L. flexuosa, PL XIX., 
Fig. 7. Synonyms, Ptychina, Phil. Thyatira, Leach. Clausina 
(ferruginosa) Jefir. Shell thin, edentulous ; ligament quite in- 
ternal, oblique. Animal with a long anal tube. Distribution, 
5 species. Norway — New Zealand. Fossil, 2 species, Eocene — . 
United States, Europe. 

Psathura, Deshayes. Anterior adductor scar long, narrow; 
hinge-teeth 2.2; umbones imperceptible. 



CONCHIFEEA. 467 



ObKBis, Cuvier, 

Etymology, corlis, a basket. 

Type, 0. elegans. PL XIX., Fig. 8. 

Synonyms, Fimbria, Mubl. not Bobadscli. " Idotsea," Schutn. 

Shell oval, ventricose, sub-equilateral, concentrically sculp- 
tured ; margins denticulated witbin ; binge-teetb 2, laterals 2, 
in eacb valve ; pallial line simple ; umbonal area witb an oblique 
farrow, muscular impressions round and polished ; pedal scars 
close to adductors. 

Animal with the mantle open below, doubly fringed; foot 
long pointed ; siphonal opening single, with a long retractile 
tubular, valve ; lips narrow ; palpi rudimentary ; gills single on 
each side, thick, quadrangular, plaited, united behind. 

Distribution, 6 species. India, China, North Australia, Pacific. 

Fossil, 80 species (including sub-genera). Lias — . United 
States, Europe. 

In 0. dubia (Semi-corbis) Desh., from the Eocene, Paris, the 
lateral teeth are obsolete. 

Sub-genera. BjplicEra (corrugata), Sby. Shell globular, con- 
centrically furrowed and obscurely radiated ; ligament promi- 
nent; margins crenulated; hinge-teeth 2.2, obscure; laterals 
obsolete. Fossil, Trias — Chalk. Europe. 

Sportella, Deshayes. Like Sphsera, but with 2.1 hinge-teeth. 

? Unicardium, D'Orb. (Mactromya, Ag. part.) = Corbula 
cardioides, Sby. Shell thin, oval, ventricose, concentrically 
striated ; ligamental plates elongated ; pallial line simple ; hinge 
with an obscure tooth, or edentulous. Fossil, 40 species ? Lias 
— Portlandian. Europe. 



? TAifCEEDiA, Lycett, 1850- 

Dedicated to Sir Thomas Tancred, Bart., founder of the 
Cotteswold Naturalists' Club. 

Example, T. extensa, L. PI. XXL, Pig. 22. 

Synonym, Hettangia, Turquem. 

Shell trigonal, smooth ; anterior side usually longest ; cardi- 
nal teeth 2.2, one of them small ; a posterior lateral tooth in 
each valve ; ligament external ; muscular impressions oval ; 
pallial line simple. 

Fossil, 12 species. Lias — Bath Oolite. Britain, France. 



458 MAlSrUAL OF THE MOLLTJSCA. 

DiPLODONTA, Brorm. 

Etymology, diplos, twin, odonia, teetn. 

Synonym, Sphserella, Conrad. 

Type, D. lupinus (Yernis) Brocclii. PL XIX., Pig. 9. 

Shell sub -orbicular, smooth. ; ligament double, ratber long, 
sub -marginal ; binge -teeth 2.2, of which the anterior in the 
left valve, and posterior in the right, are bifid ; muscular im- 
pressions polished, anterior elongated. 

Animal with the mantle-margins nearly plain, united ; pedal 
opening large, ventral ; foot pointed, hollow ; palpi large, free ; 
gills two on each side, distinct, the outer oval, inner broadest 
in front, united behind; branchial orifice small, simple; anal 
larger, with a plain valve. 

Distribution, 40 species. West Indies, Eio, Britain, Medi- 
terranean, Eed Sea, West Africa, India, Corea, Australia, Cali- 
fornia. D. diaphana (Felania, Eecluz) burrows in sand. 

Fossil, 30 species. Eocene — . United States, Europe. 

? Scacchia, Philippi, 1844 ; Tellina elliptica, Sc. Shell minute, 
ovate, posterior side shortest ; hinge-teeth 1 or 2, laterals obso- 
lete ; ligament minute ; cartilage internal, in an oblong pit. 
Animal with mantle widely open ; siphonal orifice single ; foot 
compressed, linguiform ; palpi moderate, oblong. Distribution, 
2 species. Mediterranean. Fossil, 1 species. Pliocene, Sicily. 

? Cyamium, Philippi, 1845. C. Antarcticum, PI. XIX., 
Eig. 16. Shell oblong; hinge-teeth, 2.2, ligament double; 
cartilage in a triangular groove behind the teeth in each valve. 
Distribution, 3 species. Patagonia, Northern Europe. Fossil^ 
1 species. Tertiary, Europe. 

Ungtjlin'A, Daudin. 

Etymology, ungulina, like a hoof. 

Type, TJ. Oblonga. PI. XIX., Fig. 10. 

Shell sub-orbicular ; ligament very short ; epidermis thick, 
wrinkled, sometimes black; hinge-teeth 2.2; muscular im- 
pressions long, rugose. 

Animal with the mantle open below, fringed ; siphonal orifice 
single ; foot vermi-form, thickened at the end and perforated, 
projecting from the base of the shell or folded up between the 
gills , palpi pointed ; gills two on each side, unequal, the 
external narrower, with a free dorsal border, inner widest in 
front. 

Distribution, 4 species. Senegal, Philippines, excavating 
winding galleries in coral. 



CONCSirERA. 459 



Kellia, Tutton, 1822. 

Mtymohgy, named after Mr. O'Kelly, of DuTblin. 

Synonyms, Lasea (Leach.), Br. 1827. Cycladina (Adansonii) 
Cantr. Bornia (sub-orbicularis) Phil. Poronia (rubra), Ptecluz 
(not Willd). Erycina (cycladiformis), Desh. (not Lam.) 

Types, K. sub-orbicularis, Mont. K. rubra. PL XIX., 
Mg. 12. 

Bhell small, thin, sub-orbicular, closed ', beaks small ; margins 
smooth ; ligament internal, interrupting the margin (in K. 
suhorbicularis), or on the thickened margins (in K. rubra) ; 
cardinal teeth 1 or 2, laterals 1 — 1 in each valve. 

Anintal with the mantle prolonged in front into a respiratory 
canal, either complete (in K. suborhicularis) or opening into the 
pedal slit (in ^. rubra) ; foot strap-shaped, grooved ; gills large, 
two on each side, united posteriorly, the external pair narrower 
and prolonged dorsally ; palpi triangular ; posterior siphonal 
orifice single, exhalent. 

The hinges of these little shells are subject to variations, 
which are not constantly associated with the modifications of 
the mantle-openings. They creep about freely, and fix them- 
selves by a hyssus at pleasure. K. r'abra is found in crevices of 
rocks at high-water mark, and often in situations only reached 
by the spray, except at spring-tides; other species range as 
deep as 200 fathoms. K. Lajperousii (Chironia), Desh. PL XTX., 
Fig. 11, was obtained, burrowing in sandstone, from deep 
water, at Monterey, California. 

Distribution, 20 species. Norway — New Zealand — California. 

Fossil, 20 species. Eocene — . United States, Europe. 

Sub-genera. Turtonia (minuta), Hanley. Shell oblong, in- 
equilateral, anterior side very short ; ligament concealed 
between the valves ; hinge-teeth 2.2. Animal with the 
mantle open in front ; foot large, heeled ; siphon single, 
slender, elongated, protruded from the long end of the shell. 
Distribution, Greenland, Norway, Britain. In pools and cre- 
vices of rocks between tide-marks, and in the roots of sea- 
weeds and corallines. Mr. Thompson obtained them from the 
stomachs of mullets taken on the north-east coast of Ireland. 

Pythina (Deshayesiana), Hinds. (MylUta, D'Orb, and Eecl.) 
Shell trigonal, divaricately sculptured ; ligament internal ; right 
valve with 2 lateral teeth, left with 1 cardinal and 2 laterals. 
Distribution, 8 species, New Ireland, Australia, Philippines. 
Fossil, 2 species. Eocene — , Erance, Java. 

x2 



460 



MANUAL OP THE MOLLUSCA. 



MoNTAcxJTA, Tm^ton. 

Dedicated to Colonel George Montagu, the most distlnguislied 
of the earlier English malacologists. 

Type, M. substriata. PI. XIX., Fig. 13. 

Shell minute, thin, oblong, anterior side longest ; hinge-line 
notched ; ligament internal, between 2 laminar, diverging 
teeth (with a minute ossicle. Loven.) 

Animal with the mantle open in front ; margins simple ; 
siphonal orifice single ; foot large and broad, grooved. 

The Montacutce moor themselves by a byssus, or walk freely ; 
M. siihstriata has only been found attached to the spines of the 
purple heart-urchin [Spatangus purpureus) in 5 — 90 fathoms. 
M. hidentata burrows in the valves of dead oyster- shells. 

Distribution, 3 species. United States, Norway, Britain, 
.^gean. 

Fossil, 2 species* Pliocene — . Britain. 



<r £y 



Lepton, Turton. 

Etymology, lepton, a minute piece of money (from leptos^ thin).- 
Synonym ? Solecardia (eburnea) , Conrad, Lower California. 
Type, L. squamosum. PI. XIX., Fig. 14. Fig. 256. 
Shell sub-orbicular, compressed, smooth, or shagreened, a 
little opened at the ends and longest behind; hinge -teeth 0.1 

or 1.1 in front of an angular 
cartilage notch; lateral teeth 
2.2 and 1.1. 

Animal with the mantle [m] 
©ijen in front, extending beyond 
the shell, and bearing a fringe 
of filaments, of which one in 
front [t) is very large ; siphon 
(s) single, gills two on each side, 
separate ; foot (/) thick, tapering, heeled and grooved, form- 
ing a sole or creeping disk. (Alder.) 

Sub-genus. Scintilla (Cum.ingi), Desh. 1856. Small shells 
resembling Lepton ; minutely punctate ; ligament internal, 
oblique; hinge-teeth 1. 2; posterior laterals 1. 2. Distribu- 
tion, 37 species (?), Philippines, North Australia, Panama. 

Distribution, 50 species. United States, Britain, Spain. 
Laminarian and Coralline Zones. 

Fossil, 5 species. Pliocene — . United States, Britain. 




Fig. 256. Lepton. 



CONCHIFEEA. 461 

Galeomma, Turton. 

Synonyms, Hiatella, Costa (not Daud.) ; Partlienopea, ScaccH 
(not Pabr). 

Type, Gr. Turtoni, PL XIX., Fig. 15. [Galee, weasel, omma, 
eye.) 

Shell tMn, oval, equilateral, gaping widely below ; invested 
with a thick, jfibrons epidermis ; beaks minute ; ligament 
internal; teeth 0.1. 

Animal with the mantle-lobes united behind and pierced 
with one siphonal orifice, margins double, the inner with a row 
of eye-like tubercles ; gills large, sub-equal, united behind ; 
lips large, palpi lanceolate, plaited; foot long, compressed, 
with a narrow flat sole. 

The Oaleomma spins a byssus, but breaks from its mooring 
at will and creeps about like a snail, spreading out its valves 
nearly flat. (Clarke.) 

Distribution, 14 species. Britain, Mediterranean, Mauritius, 
Pacific. 

Fossil, 1 species. PKocene — . , Sicily. 

PAMILT XII. — CTCLADIDiE. 

Shell sub -orbicular, closed ; ligament external ; epidermis 
thick, horny ; umbones of aged shells eroded ; hinge with car- 
dinal and lateral teeth ; pallial line simple, or with a very 
small inflection. 

Animal with mantle open in front, margins plain ; siphons 
(1 or 2) more or less united, orifices usually plain ; gills 2 on 
each side, large unequal, united posteriorly ; palpi lanceolate ; 
foot large, tongue- shaped. 

All the shells of this family were formerly included in the 
genus Gyclas, a name now retained for the small species inha- 
biting the rivers of the north temperate zone ; the Cyrence are 
found in warmer regions, on the shores of creeks and in brackish 
water, where they are gregarious, burying vertically in the 
mud, and often associated with members of marine genera. 

Cyclas, Bruguiere. 

Etymology, JcuJclas, orbicular. 
Type, C. Cornea. PL XIX., Pig. 11. 

Synonyms, Sphserium, Scop. Pisum, Muhlf. (not L.) Mus-" 
oulium, Link. 



462 MANTJAL OF THE MOLLUSCA. 

Shell thin, ventricose, nearly equilateral; cardinal teeth 2.1, 
minute, laterals 1 — 1 : 2 — 2, elongated, compressed. 

Animal ovo -viviparous ; siphons partly united, anal shortest, 
orifices plain, gills very large, the outer smallest, with a dorsal 
flap ; palpi small and pointed. 

The fry of Cyclas are hatched in the infernal branchiae, they 
are few in number and very unequal in size ; a full-grown 
O. cornea has about 6 in each gill ; the largest being -g^ to ^ the 
length of the parent. The young Cydades and Fisidia are very 
active, climbing about submerged plants and often suspending 
themselves by byssal threads ; the stiiated gills and pulsating 
heart are easily seen through the shell. 




I 

Fig. 257. Pisidium amnicum, ■§, with its foot protruded. 

Sub-genera, Pisidium, Pfr. P. amnicum, PI. XIX., Fig. 18. 
Shell inequilateral, anterior side longest ; teeth stronger than in 
Cyclas. Animal with a single, small, excurrent siphon ; bran- 
chial and pedal orifices conHuent. 

Distrihution, 60 species. United States, South America, 
Greenland, Norway, Sicily, Algeria, Cape, India, Caspian, 
Britain. 

Fossil, 38 species. "Wealden — . Europe. 

Ctrena, Lamarck. 

Etymology, Gyrene, a nymph. 

Ty^e, C. cyprinoides, PI. XIX., Pig. 20. 

Shell oval, strong, covered with thick, rough epidermis ; 
ligament thick and prominent; hinge-teeth 3.3, laterals 1 — 1 
in each valve ; pallial line slightly sinuated. 

Animal (of type) with the mantle open in front and below, 
margins plain ; siphons short, orifices fringed ; gills unequal, 
square in front, plaited, inner lamina free at base ; palpi lanceo- 
late ; foot strong, tongue-shaped. 

Sub-genera, Corbicula, Muhlf. C. consobrina, PI. XIX., 
Pig. 21. Shell orbicular, concentrically furrowed, epiderrais 
polished ; lateral teeth elongated, striated p-cross. 



COKCHIFERA. 463 

Batissa, Gray. Anterior lateral teeth short "; imder ones long. 

Velorita, Gray. Anterior laterals thick and triangular. 

Distribution, 130 species. Tropical America (eastern), Egypt, 
India, China, Australia, Pacific Islands. In the mud of rivers, 
and in mangrove swamps, usually near the coast. C. consohrina 
ranges from Egypt to Cashmere and China, and is found fossil 
in the Pliocene formations of England, * Belgium, and Sicily. 

Fossil, 105 species. Wealden — . Eurone, United States. 

? Cyren-oldes, Joannis. 

Synonym, Cyrenella, Desh, 

Type, C. Dupontii, PL XIX., Eig. 19. 

Shell orbicular, ventricose, thin, eroded at the beaks ; epi- 
dermis "dark olive; ligament external, prominent, elongated; 
cardinal teeth 3.2, the central tooth of the right valve bifid; 
muscular impressions long, narrow ; pallial line simple. 

Animal with the mantle open in front and below, margin 
simple, siphons short, united ; palpi moderate, narrow ; gills 
very unequal, narrow, united behind ; foot cylindrical elongated. 

Distribution, 4 species. Biver Senegal. The marine species 
are Dvplodontoe. 

Fossil, 1 species. Europe. 

Eamily XIII.— Cypiuntdje. 

Shell regular, equivalve, oval or elongated; valves close, 
solid ; epidermis thick and dark ; ligament external, conspicu- 
ous ; cardinal teeth 1 — 3 in each valve, and usually a posterior 
lateral tooth ; pedal scars close to, or confluent with, the 
adductors ; pallial line simple. 

Animal with the mantle-lobes united posteriorly by a curtain, 
pierced with two siphonal orifices ; foot thick, tongue-shaped ; 
gills 2 on each side, large, unequal, united behind, forming a 
complete partition ; palpi moderate, lanceolate. 

One half the genera of this family are extinct, and the rest 
(excepting Circe) were more abundant in former periods than at 
the present time, Cyprina and Astarte are boreal forms ; Circe 
and Cardita abound in the Southern seas. 

Cypeii^a, Lamarck. 

Etymology, Kuprinos (from Kupris), related to Venus. 
Type, C. Islandica, PI. XIX., Eig. 22. 

♦ Associated with the bones of Elephns meridionalis, Bhinoceros leptorhinus^ 
Mastodon Arvemensis, Hippopotamus major, S(o. 



464 MAliTUAL OF THE M0ILT7SCA. 

Synonym, Arctica, Schum. 

Bhell oyal, large and strong, with usually an oblique line or 
angle on the posterior side of each valve ; epidermis thick and 
dark ; ligament prominent , umbones oblique ; no lunule ; 
cardinal teeth 2.2, laterals — 1, 1 — 0; muscular impressions 
oval, polished ; pallial sinus obsolete. 

Animal with the mantle open in front and below, margins 
plain; siphonal orifices close together, fringed, slightly pro- 
jecting ; outer gills semilunar, inner truncated in front. 

The principal hinge -tooth in the right valve of Cyprina 
represents the second and third in Venus and Cytherea ; the 
second tooth of the left valve is consequently obsolete. 

Distribution, C. Islandica ranges from Greenland and the 
United States to the Icy Sea, Norway, and England ; in 5 — 80 
fathoms water. It occurs fossil in Sicily and Piedmont, but not 
alive in the Mediterranean. 

^oss?7, 90 species. (D'Orbigny.) Muschelkalk — . Europe. 

CiECE, Schumacher. 

Etymology, in Greek mythology a celebrated enchantress. 

Example, 0. corrugata, PL XX., Pig. 2. 

Synonym, Paphia (undulata), Lamarck.* 

Shell sub-orbicular, compressed, thick, often sculptured with 
diverging strise; umbones flat; lunule distinct; ligament 
nearly concealed ; margins smooth ; hinge-teeth 3:3 ; laterals 
obscure ; pallial line entire. 

Animal (of C. minima) with the mantle open, margins denti- 
culate, siphonal orifices close together, scarcely projecting, 
fringed ; foot large, heeled ; palpi long and narrow, Eanges 
from 8 — 50 fathoms. (Forbes.) 

Distribution, 40 species, Australia, India, Eed Sea, Canaries, 
Britain. 

AsTAUTE, Sowerby, 1816. 

Synonym, Crassina, Lamarck. Tridonta, Schum. Goodallia, 
Turton. 

Example, A. sulcata, PI. XX,, Pig. 1. A. borealis. Pig. 258. 
{Astarte, the Syrian Yenus.) 

Shell sub-orbicular, compressed, thick, smooth or concen- 

* This name was employed by Bolten, in 1798, for sp. of Veneridce, and by Lamarck, 
in 1801, for Venus divaricata, Cbemn. (= Circe divaricata and Crassatella contraria), 
and Mesodesma glabratum. In 1808, Fabricius adopted the name for a group of butter- 
flies, in which sense it is now widely employed, liaving been abandoned by Lamarck ii) 
hia later works, and by all succeeding malacologists. 



CONCHIPERA, 



465 



trically furrowed ; lunule impressed ; ligament external ; epir 
dermis dark; hinge-teeth 2.2, the anterior tooth of the right 
valve large and thick ; anterior pedal scar distinct ; pallial line 
simple. 

Animal -mth. mantle open; margins plain or slightly fringed ; 
siphonal orifices simple ; foot moderate, tongue- shaped ; lips 
large, palpi lanceolate ; gills nearly equal, united behind, and 
attached to the siphonal band. 

The animal oiAstarte horealis is shown in Fig. 258; mantle- 
margins free, plain, slightly cirrated in the branchial region ; 
united posteriorly by the branchial septum, forming a single 
excurrent orifice ; pedal muscles {p p), distinct from adductors ; 
gills flat, finely striated, destitute of internal partitions ; outer 




Fig. 258. Astarte horealis, var. semi-sulcata, Leach, |-= Wellington ChanneL 

gill narrow, elliptical, with a simple margin ; inner gill grooved, 
conducting to the mouth. 

Distribution, 20 species. Behring's Straits, "Wellington Chan- 
nel, Kara Sea, Ochotsk, United States, Norway, Britain, 
Canaries, -^gean (30 — 112 fathoms). 

Fossil, 285 species. Carb. — . North and South America, 
Europe, Thibet. 

? Digitaria, Wood ; Tellina digitaria, Lower Mediterranean* 

Fossil, Pliocene, Britain. 



GouLDiA, C. B. Adams. 

STiell minute, triangular, furrowed • hinge like Astarte , witli 
lateral teeth ; pallial line simple. 
JMstrihution, 7 species. Panama, West Indies. 

X 3 



466 



MAirtTAI. OF THE MOLLITSCA* 



Ceassatella, Lamarck. 

Synonyms^ Ptycliomya, Ag. Paphia (Lamarck, part) Koissy. 

Type, C. ponderosa, PL XXL, Pig. 4. C. pulchra. Fig. 259. 

Etymology, crassus, thick. 

Shell solid, yentricose, attenuated behind, smooth or con- 
centrically furrowed ; lunule distinct ; ligament internal ; 
margin smooth or denticulated ; pallial line simple ; hinge- 
teeth 1.2, striated, in front of cartilage pit ; lateral teeth — 1, 
1— ; adductor impressions deexD, rounded ; pedal small, 
distinct. 

Animal with mantle -lobes united only by the branchial 
septum ; inhalent margins cirrated ; foot moderate, compressed, 
triangular grooved; gills smooth, unequal, outer semi-lunar, 
inner widest in front ; palpi triangular. 




Fig. 259. Crassatella pulchra. Sandj^ Cape, J. E. Jukes. 
Animal as seen on the removal of right valve, and portion of the ipaantle. 

In Crassatella pulchra the animal is like Astarte ;■ foot lingui- 
form, slightly grooved; palpi short and broad, few-plaited; 
outer gill narrower in front. 

Distribution, 34 species. Australia, New Zealand, Philippines, 
India, West Africa, Canaries, Brazil. 

Fossil, 64 species. Neocomian — . Patagonia, tTnited States, 
Europe. 

IsocAEDlA, Lamarck. Heart-cockle. 

Etymology, isos, like, cardia, the heart. 
Type, I. cor. PI. XX., Fig. 3. 



CON-CHIFEEA. 467 

Synonyms^ Glossus, Poll ; Bucardium, MuMfeldt ; Peccliiolia, 
Meneghini. 

Shell cordate, ventricose ; •umbones distant, sub-spiral ; 
ligament external; hinge-teeth 2.2 ; laterals 1 — 1 in each valve, 
the anterior sometimes obsolete. 

Animal with the mantle open in front ; foot triangular, 
pointed, compressed; siphonal orifices close together, fringed; 
palpi long and narrow ; gills very large, nearly equal. 




Fig. 260 Isocardia cor. 

The heart-cockle burrows in sand, by means of its foot (/), 
leaving only the siphonal openings exposed. (Bulwer.) 

Distribution, 5 species. Britain, Mediterranean, China, Japan. 

Fossil, 90 species. Trias — . United States, Europe, South 
India. 

The Isocardia- shaped fossils of the old rocks belong to the 
genera Cardiomorpha and Iso-arca ; many of those in the 
Oolites to Ceromya. Casts of true Isocardice have only two 
transverse dental folds between the beaks, and no longitudinal 
furrows. 

Cyphicaedia, Lamarck. 

Example, C. obesa, PL XX., Fig. 4. C. rostrata. Fig. 261. 

Syno7iyms, Trapezium, Humph. Libitina, Sch. 

Shell oblong, with an oblique posterior ridge ; umbones 
anterior depressed; ligament external, in deep and narrow 
grooves ; cardinal teeth 2.2, laterals 1 — -1 in each valve, some- 
times obscure ; muscular impressions oval (of two elements) ; 
pallial line simple. 



468 



MAircTAL OF THE MOItTTSCA. 



Animal (of C. solenoides) with mantle-lobes united, cirratel 
behind ; pedal opening moderate ; foot small, compressed, with 
a large byssal pore near the heel ; siphons short, conical, unequal, 
cirrated externally ; orifices fringed ; palpi small ; gills unequal, 
the outer narrower and shorter, deeply lamellated, united 
posteriorly, the inner prolonged between the palpi. 

Animal of Ct/joricardia rosfrafa, Lamarck, Philippines (Fig. 

300), with mantle-lobes united, 
and covered with wrinkled epi- 
dermis ; siphonal orifices fringed; 
gills deeply plicated, anterior 
part of the outer gill united to 
the inner ; dorsal border narrow, 
plaited ; adductor muscles of two 
elements, 
Eed Sea, India, and Australia. In 




North America and 



Fig, 261. Cypricardia, 

Distribution, 13 species, 
crevices of rock and coral. 

Fossil, 60 species. Lower Silurian 
Europe. 

? Sub-genera. Coralliophaga, Bl. C. coralliophaga, Lamarck. 
Shell long, cylindrical, thin, slightly gaping behind ; hinge- 
teeth 2.2, and a laminar posterior tooth ; pallial line with a wide 
and shallow sinus. Distribution, 5 species, Mediterranean, iji 
the burrows of the Lithodomus ; sometimes two or three dead 
shells are found one within the other, besides the original owner 
of the cell ; South Sea. 

? Cypricardites, Conrad (part). An. Geol. Eep., 1841. (Sap.- 
guinolites, M'Coy.) Employed for Cypr