‘ oy nie 4 / after Owen’) * 7 g 72 __ Hood 00 Latertor atagttations a_—_ The mantle 6___Tts dorsal told e—__ NMidamental Gland bee | p— Tentacles | ———. tive : g——_Sheil UML Ae UU Siphorw va Septa x Last (hamber A Fianet ” TWLowny fc. MANUAL OF THE MOLLUSCA: A TREATISE ON RECENT AND FOSSIL SHELLS.) S. P. WOODWARD, A.LS., MIN. AND GEOL. ASSISTANT, BRITISH MUSEUM. WITH NUMEROUS ILLUSTRATIONS BY A. N. WATERHOUSE anv J. W. LOWRY. Second (| % cs dition. LONDON: VIRTUE BROTHERS & CO., 26, IVY LANE, PATERNOSTER ROW. “cael ; PREFACE. Tis Manual, which 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 Rang, incomparably the best work of its kind—for an acquaintance with which the author was indebted to his friend and master, Wiir1am LonspALE— 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. Enwarp Forszxs; without whose approval he seldom added to, or deviated from, the ee and plan of the ‘History of British Molluscea.”’ That he was sight in taking this course, has been sanctioned by the highest authority in this country ;—since the same scheme has been employed by Prof. Owrn in the Hunterian Lectures and Catalogue. It has also been adopted by Dr. E. Barrovurin the Madras Museum; by the Rev. Prof. Henstow, in his Report to the British Association on the Formation of’ _ Typical Collections; and by Prof. Morris in his Catalogue of British Fossils. It was the writer’s desire, by abstaining from the intro- 1V 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 Natural History Classes in the Universities. To facilitate reference, and meet thé mést general require- ments, the number of large groups*and géhera of shells ‘has been restricted as much as possible,, amd 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 zn ztalics ; the writer’s own wishes coincide with those of the distinguished botanist Sir J. E. Surrn, that ‘‘the system should not be encumbered with such names ;” but they have been admitted in deference to custom and general opinion.* t f . The rules of the British Association, intended to secure uniformity, have called into existence afew active opponents, seeking to distinguish themselves by the employment of pre- Linnean and MS. names, on the pretence of carrying out the “Jaw of priority ” (p. 48). But this folly has reached its height, and will fall into cae: when it has lost its ‘novelty. i The investigation of dates is the tnost disheartening work upon which the time of an author can be employed; it. is never safe to take them seéond+hand, and even reference to the original works is not always satisfactory.} 3 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 French genus-makers will be found carefully recorded in the “ Index Generum Malacozoorum,” by the accurate and \amented Dr, Herrmannsen, a work indispensable to every writer on Conchology. + One’ example will suffice. In an “Atheneum” report, by Prof. E. Forbes, the _name “ Lottia fulva” was misprinted “ Jothia fulva;” but although immediately corrected, the erratum was formally installed as a “new genus,” in the vat of Gray, Philippi, Catlow, Adams, and other conchologists ! t The dates on the title pages of Journals and Transactions of Scientific Societies, are not usually dates of publication, but refer to the years for which they are issued to the subscribers. It is almost impossible afterwards to. correct these false dates, ¢ . PREFACE. Vv asthe value of species and genera, and the laws of geogra- phical and geological distribution. Itis 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. For to the thoughtful and earnest investigator, 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 accidéntal, 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. Waterhouse, of Marlborough House, from original drawings by the Author; and although printed from stereo- types, they have the advantage of mae ely representing what was wished to be shown.” The engravings of Mr. Wilson Lowry speak for itidingelses many of the figures are fromthe 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 = Vi PREFACE. 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 I. is devoted to the Sy- nopsis of the Genera. ~The chapter on Tunicata has been omitted, since they are more nearly, allied to the Polyzoa than to the Mollusca proper, and since the treatment of the Molluscoidan 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 Polyzoa) than to describe them in the present work. The book has been subjected to a complete revisal, and numerous alterations and additions have been made; but the reviser has interfered as littlé as possible ' with the Author’s original » classification and systematic ~ arrangement. , Ac Ti. _Sept., 1866. me chee” > a” » 3 "ds * ~ > "S.R- ‘CONTENTS. PART I. CHAPTER I. PAGE On THE Position or THE Moxivusca IN THE ANIMAL Kincpom. —Characters of the five primary groups, or sub-kingdoms :— Vertebrata — Mollusca—Annulosa— Coelenterata— Protozoa. Their antiquity ....... SOR CRIMLT fo awed tweed. commen Cuasses oF Mottvsca. 1h. Cephalopoda.—2. Gasteropoda.— 3. Pteropoda.—4. Brachiopoda.—s. Lamellibranchiata ... Hanis anp co OF THE Moiivsca.—Sedentary tribes, their mode of att ent; locomotive tribes, their means of pro- gression; § ons frequented "a shell-fish.— Food : vege- 3—7 table, infusorial, and animal feeders.—Use of shell-fish to. other animals for food; wse.of shells fer ornamental and other purposes; prices of shells.*-Longevity of molluscous animals; tenacity of lift 5 fecundity; we, &oe sgueeres Sz 715 Srrvucrunz axp Puystoxocy. oF THE Moxiusca.— Nervous system; organs of sense.— Muscular system.—Digestive system ; Boca teeth; secretions. Ey wanetese system ; aquiferous canaidl Heaittabery: system.*—-The shell, its composition and ‘structure; nacreous, fibrous, and porcele lanous shells; epidermis; erosion of fresh-water shells.— Formation and growth of the shell; adult characters; de- collated shells; monstrosities;- colours; the operculum; homologies.—Temperature and hybernation.—Reproduction : of lost parts; by gemmation; viviparous; alternate; ovipa- ae VON i LS aie 5 cts ste eves de seve ueavon _Crassirication.—Afiinities; analogies; spetics ; eenera; families ; the quinary system; yon ans: ‘authorities ; types ; abbre- 15—4d Viations Core ee essere sessee ee ee ee ee ee ee i) 45—49 29125 Vil CONTENTS. CHAPTER II. PAGE GEOGRAPHICAL DuistrisutTion.—Land provinces; marine pro- vinces.—Specific areas; specific centres.—Generic areas; sub-generic areas.— Boundaries; influence of climate.—Origin BERT AVIDODS? Sos tv onus bide ace cies bs. .d0 vote Marine Provinces.—Arctic genera; tropical genera; Cosmopo- MenPeNOCIGHs., ... so6ss vnsety een oye 0 gre als 00 05 6 ann I. ~Arctic Province ! ixis's 4s fhe Bev 5s os “ II. Boreal Province: Norway, New England ..... aks III. Celtic Province: Britain, Denmark .. ../it ese TV. Lusitanian Province: Portugal, Canaries, er Azores, Mediterranean, Black Sea ............ Y. se CONTENTS. 1X PAGE fen tapna and New Ireland ws. .ccsds ues cvsvcuns sass . LOS SR MeRr RAE HOGIOD'S 5. cove os codons 6c cde os ths 103 13. South Australia and Tasmania .............000. ~ 104 NOMAD wes eiaw ben» a pane Guages ov ciune 104 15. Polynesian Region: Salomons, New Hebrides, New Caledonia, Feejees; Friendly, Navigator’s, Society Islands ; Low Coral Islands; Sandwich Islands 104 16. Canadian Regions; New England ................ 106 Pepe EPANEIO DUAR Gs cna eee cave adescccdensine dears 107 eeeremerienn Reon... 226. oo Ue oe PORE 108 Meee Creeror ANd: CaliOrnie o. + score ca eee ea ead 6 od melee 109 PE MCIORTA RESTON” 5 7's.rtee tdie 2 tSbk wiiwia nda coho pees 109 RE EREMEIES Ceo od 5 iv a 3d Cle Me athe, | iWloR ks carves Sosa ees 110 22. Columbian Region: Galapagos PB ig AS abe 81S cw wade hea 111 : Benger SPAR AT EPION 55. sie ak on oe tee oss ee ee: 112 Se ere taal POOP IOR. 6622 aon she ove atew ces Mtly saa ee 113 Seem etecembetticy LOMTOTE: ih, oo sss eens «ons asthe we ewes 114 26. Chilian Region: Juan Fernandez ~.......eeeeeeee 114 27. Pata@zonian Region: Fuegia, Falklands ............ 115 ._ * CHAPTER II. DIstTRIBUTION OF THE Mogivsca Iv Time.—Geological Table; distribution of Species in the Strata; of Genera; table of Characteristit genera ; table showing range of genera; range of families; numerical development in time. ae of appear- _ ance of groups of cle order of succession.—Migration of species and diffusio era in former times.—Method of Geological inaaieaiten —Tertiary Age. Secondary Age.—_ Paleozoic Age.- Numerical = ivine and fofsil species.. ++ olla Str renee eee renee GORI tases s + ahead . . ‘e~ “CHAPTER Ly. On Corrective Suetis.—Land-shells; elevation on mountains. —Fresh-water shells.—Sca-shells, littoral species ; floating mollusca: the towing-net; trawling; kettle-nets ; deep-sea 117 fishery ; trapping whelks; dredging............seeeseeeee 136 Dredging papers, by M‘Andrew and Barrett, Norway....-...... 144 Dredging papers, by: Forbes FECA ese rece vcveceennens 148 Zones of depth: littoral ; aati coralline ; deep-sea coral POE eee Cre es SL, EO a 161 Preservation of Molluscous animals f for ei ese Meas LOO er) CONTENTS. | PART I. SYNOPSIS OF THE GENERA. CHAPTER I. PAGE Ciass I. Cerwanoropa. Orper I. DrpraN@HIATA ........06+4 155 Peron. A. ‘Ocrorona ' v9) fatale eenten «cae nveinienla ee 158 Fam. I. Argonautide.—Argonauta ........++.. sed pneae 161 Fam. II. Octopodide.—Octopus, Pinnoctopus, Eledone, Cir- roteuthis, Philonexis, Sczeurgus, Boliteena ...........+-- 163 — MZCTION .D. + IDEGAPODA .ois.cccsccscsiee peene + se see 166 Fam. III. TZeuthide.—Loligo, Gonatus, Sepioteuthis, Beloteuthis, Geoteuthis, Leptoteuthis, Cranchia, Sepiola, Loligopsis, Cheiroteuthis, Histioteuthis, Omyéhoteuthis, Enoploteuthis, Ommastrephes, Thysanoteuthis, g cnet Plesioteuthis, Dosidicus .. 0.5... sei v- +a see 167 Fam. IV. Belemnitide.—Belemnites, "Belemnitella, Xipho- teuthis, Acanthoteuthis, Belemnoteuthis, Conoteuthis Be Fam. V. Sepiade.—Sepia, Spirulirogtra, Beloptera, Belem- moo, Helosruas. 7.5. S05). cas SAT cases ae 176 _— Fam. VI. Spirulide.Spirula .......0.0 000s &...| 0. P78. Orper II. TrTRABRANCHIATA .....4. Bes Ae ns ss se One ee Fam. I. Nautilide.—Nautilus, Lituites, “Trochoceras, Cly- MIP ONI DG Sai aby el eer EO oa, Me... 185 _— ” Fam. II. Or their atide.—Orthoceras, Gomphoceras, Onco- ceras, Phragmoceras, Cyrtoceras, —s Thoracoceras, . Nothoceras : Fam. III. -Ammonitide. —Goniatites, Rhabdoceras, Bactrites, Ceratites, Ammonites, Crioceras, Toxoceras, Ancyloceras, Scaphites, Helicoceras, Turrilites, Hamites, Ptychoceras, aretha 5, 6s vould ob atde ax atc doen 04 greene ec 195 _ CHAPTER LL. : Cu des at APARPEROPODA 5 ficckic cid lvls tbe ee W colds oe sale See ce ZO. = ORDER I. PROSOBRANCHIATA.... cealse. sae oes eo ee en fea 209 Srcrion A. Bhaesea hoc ga. | ee Fam. I. Strombide. -—itrombus, 2 Rostellaria, Seraphs ore \« a) @ noe vee aden ees codes ee eee faeces ecece 210 , ; % * he. - Cap - ‘ ‘ = ee Se 190 — CONTENTS. xi PAGE Fam. I. Muricide.—Murex, Typhis, Pisania, Ranella, Triton, ~ Fasciolaria, Turbinella, Cancellaria, Dibaphus, Tricho- tropis, Pyrula, Fusus ......... Sein WO ah 5/0 = ah ob de Sharmrad 212 Fam. III. JBuwuccinide.— Buccinum, Pseudoliva, Anolax, Halia, Terebra, Eburna, Nassa, Phos, Ringicula ?, Purpura, Purpurina, Rhizochilus, Monoceros, Pedicularia, Ricinula, Planaxis, Magilus, Cassis, Oniscia, Cassidaria, Pachyba- thron, Dolium, Harpa, Columbella, Oliva, Ancillaria .... 218 Fam. 1V. Conide.—@onus, Pleurotoma, Cithara .......... 228 Fam. V. Volutide.—Voluta, Cymba, Mitra, Volvaria, Mar- SEED cialhas sce ce «vests Siakgin’'s/sl sre chal ite svg wcnrerste: eae areca emo Fam. VI. Cypreide.—Cyprea, Erato, Ovulum .......... 232 Section B. HoLosToMaTA .......... weed. Mes aaee sees 234 Fam. I. WNaticide.—Natica, Deshayesia, Naticella, Sigaretus, Lamellaria, Narica, Velutina, Cryptocella ...........00- 238 Fam. Il. Pyramidellide.—Pyramidella, Odostomia, Chem- nitzia, Kuliima, Monoptigma, Aclis, Styloptygma, Myonia, Leucotina, Stilifer, Loxonema, Macrocheilus ............ 238 Fam. III. Cerithiade.—Cerithium, Potamides, Nerinza, Fastigiella, Aporrhais, Struthiolaria .......ceeceeeeeenes 242 Fam. IV. Melaniade.—Melania, Paludomus, Melanopsis .. 246 Fam. VY. Turritellide.—Turritella, Czecum, Vermetus, Sili- ears, DCAIATIA., <.0005 005 re ee eee eh rote 248 Fam. VI. Littorinide.—Littorina, Solarium, Phorus, Lacuna, Litiopa, Rissoa, Skenea, Truncatella ?, Lithoglyphus .... 250 Fam. VII. Paludinide.—Paludina, Ampullaria, Amphibola, Valvata .....4 . te” SE aie SS ee ‘ae 257 Fam. VIII. WNeritide.—Nerita, Pileolus, Neritina, Navicella 260 Fam. IX. Turbinidé Turbo, Phasianella, Imperator, Tro- chus, Rotella, Monodontaj»Delphinula, Adeorbis, Euom- phalus, Stomatella,,Brodemipia. f...05,. 00sec cc cee eee 263 Fam. X. Haliotis.—Haliotis, Stomatia, Teinotis, Scissurella, Pleurotomaria, Murchisonia; Trochotoma, Cirrus, Ianthina 268 Fam. XI. Fisswrellide.—Fissurella, Puncturella, cine Emarginula, Parmophorus .......... ALE rr 272 Fam. XII. Cualyptreide.—Calyptreea, Crepidula, Pileopsis, Read nin alo id's. dx.e ges « bletkane aman oa dale aged 275 Fam. XIII. Patellide.—Patella, Acmza, Gadinia, Siphonaria 278 Fam. XIV. Dentaliade.—Defitalium ............. 5 seve es 282 Fam. XV. Chitonide. —Chiton OEE «3 sun, 0S jo0 oo sta .. 282 . 7 # %. . . . >? Re eal ‘ - - Xil CONTENTS. PAGE O.uass II. GASTEROPODA. ORDER II. PULMONIFERA..:..sseccess 280 Sarton A, “INOPHROULATA |. ss. 00scsses eee ane en pier ted .. 285 Fam. I. Helicide.—Helix, Vitrina, Succinea, Bulimus, Achatina, Pupa, Cylindrella, Balea, Tornatellina, Paxillus, PEMNSTILA oy sonin'o ee ocahniis ge emote Mig fe teen ees ‘fare 288 Fam. IJ. Zimacide.—Limax, Anadenus, Incilaria, Arion, ‘Parmacella, Janella, Aneitea, Parmarion, Triboniophorus, Viquesnelia, Testacella.......... 0 Preeeeeen tS weren e Fam. III. Oncidiade.—Oncidium, Vaginulus ............ 299° Fam. IV. Limneide.—Limnea, Chilinia, Physa, anegiee PP LATICEPAS.) %.,'cct ain wie gle guretere > oe ens oe ols «sg ie 300 Fam. V. » «0. 5she en 508 a < es! oo ao ar MANUAL OF THE MOLLUSCA. | fv ie ae > CHAPTER I. ON THE POSITION OF THE MOLLUSCA IN THE ANIMAL KINGDOM. Au 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 vertebre ; while in a few it is cartilaginous, and not divided into distinct parts. Vertebrz 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 deyoted 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 Mollusca, 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 Zingula, and of a few of the Pteropoda, B 2 MANUAL OF THE MOLLUSCA. such as Conularia, are rich 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 yarious tribes of insects, spiders, crabs, starfishes, echinoderms, entozoa, and worms, have no internal skeleton ; but to compensate for it, their outer integument is sufficiently 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 grouv Homogungliata.. The neryous 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 cayity 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 shght 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 absence of any special organ. There seems to be a much closer relationship between the molluscan and the protozoic sub-kingdoms than between the molluscan 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 OF THE MOLLUSCA, 3 Protozoa. In the same way we can pass from the highest of the Annulosa to the Protozoa. But we cannot find any continuous succession of adult forms which will connect the Annulosa with the Mollusca, or the Mollusca with the Vertebrata. 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 en 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 great groups, viz., the mollusca proper and the molluscoida. 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 univalye mollusca are encephalous, or furnished with a distinct head; they have eyes and tentacula, and the mouth is armed either with jaws or with tooth straps.* Cuvier has _ * One of the drawbacks to the study of mollusca is the prevalence of such terms as jaws, arms, feet, &c. The reader must not suppose that the parts so designated are B2 4 MANUAL OF THE MOLLUSCA. divided them into three classes, founded on the modifications of their feet, or principal locomotive organs. : 1. The cuttle-fishes constitute the first class, and are termed ! Pe Sei Fig. 1.* Oral aspect of a Cephalopod. Cephalopoda,t because their feet, or more properly arms, are so attached to the head as to form a circle round the mouth. 2. In the Gasteropoda,t{ or snails, the under side of the body Fig. 2. A Gasteropod.§ Fig. 3. A Pteropod. | forms a single muscular foot, on which the animals creep or glide. homologous in the vertebrata and in the mollusca. When applied to the latter, the terms are vague and indefinite in meaning. mI * Fig. 1. Loligo vulgaris, Lam.}. From a specimen taken off Tenby, by Ge Bowerbank, Esq. The mandibles are seen in the centre, surrounded by the circular y lip, the buccal membrane (with two rows of small cups on its lobes), the eight sessile arms, and the long pedunculated tentacles (¢), with their enlarged extremities or clubs — (e). The dorsal arms are lettered d, the funnel f. + From cephale, the head, and poda, feet. See the frontispiece and pl. I. t Gaster, the under side of the body. 4 § Fig. 2. Helix desertorum, Forskal. From a living specimen in the British Museum, ~ March, 1850. ? ] Fig. 3. Hyalea tridentata, Lam., from Quoy and Gaimard, a CLASSES OF THE MOLLUSCA. 5 3. The 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 + 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 them 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 Brachionobranchia (arm-breathers) has been proposed for the erroneous one of Brachiopoda (arm-footed). 5. The Lamellibranchiata,§ 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. + Brachion, an arm. t Fig. 4. (3.) Rhynchonella psittacea, Chem. sp., dorsal valve, with the animal (after Owen). 5,6, Zerebratula australis, Quoy. From specimens collected by Mr. _ Jukes. (2.) Ideal side view of both valves (f, the cardinal muscles, by which the valves are opened). (1.) Dorsal valve. These woodcuts have been kindly lent by Mr. J. EB. Gray. § DP eentchranchinta, plate-gilled. 6 MANUAL OF THE MOLLUSCA. the Brachiopoda, form the sub-class of Molluscoida. In the first edition the T'unicata were described in detail, but they are omitted in this for reasons stated in the preface. Five of these modifications of the molluscan type of organi- sation were known to Linnzeus, 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, tobe guided by convenience, nor ‘“‘ framed merely for tLe purposes of easy remembrance and communication.” The Xi ore Fig. 7. A Bivalve,+ 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 Linnean types were—Sepia, Limax, Clio, Anomia, Ascidia, Terebratula was included with Anomia, its organisation being unknown. + Mya truncata, L.}. From Forbes and Hanley. + Ascidia mentula, Miill. Ideal representation; from a specimen dredged by Mr. . Bowerbank, off Tenby. : HABITS AND ECONOMY OF 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 OF THE MOLLUSOA. 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 open 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 lithodomus 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 brachiopoda 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 (pecten opercu- laris) swims rapidly by opening and shutting its tinted valves. Nearly all the gasteropods creep hke 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 purpure are found at low water, amongst the sea-weed; the mussel affects muddy shores, the cockle rejoices in extensive sandy flats. Most of the finely- 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 terebratule 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 ltiopa and scyllea 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 OF THE MOLLUSCS. 9 in abhorrence, and fast or shift their quarters while that crop is onthe 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 alge, 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 calyptrea, 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 earinaria and firola 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 than even salt. B 3 10 MANUAL OF THE MOLLUSCA. and cuttles, who vindicate their high position in the naturalists’ ‘‘system,”’ by preying even on fishes. As the shell-fish are great eaters, so in their turn they afford food to many other creatures; fulfilling the universal law of eating and being eaten. Civilised man still 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 haliotis, 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, off 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 (anarhicas). 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 (philine), itself predacious, is eaten both by star-fish and sea- anemone (actinia). The land-snails afford 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., carabus violaceus and goertus olens), occasionally kill siugs. The greatest enemies of the mollusca, however, are those of * See Hugh Miller’s “Scenes and Legends of the North of Scotland.” The Ajok- kenmodings, 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 MOLLUSCA, 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-fish 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 balant and sea-weed, and the ascidian with zoophytes, which form an effectual disguise; the Jima 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 obseryed in a Roman 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, too, we learn from the observations of Mr. George Roberts, of Lyme Regis, 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 fom 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 that have been given for rare shells are less to be regretted, 12 MANUAL OF 1HE MOLLUSCA. and they are the ornaments of barbarous tribes. The 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 in 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 eolis 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-fancying, or the study of old china. For educational pur- poses the best shells are the types of genera, or species which illustrate particular points of structure ; and, fortunately for students, the prices have been much diminished of late years. A Carinaria, once “ worth 100 guineas? (Sowerby), is now worth ls. 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 Cyprea umbilicata has been sold for £30. * Shell-sand is only beneficial on peaty soils, or heavy 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. HABITS AND ECONOMY OF THE MOLLUSCA. 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 dio 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 (Pl. III., fig. 3), to have lived and continued growing for many years. Many of the bivalves, like the mussel aia 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 (éridacna), 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 island’, 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 molluses 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 MANUAL OF THE MOLLUSCA. had been more than a year out of water.* The pond-snails (ampullarie) 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 haying placed a number in a drawer for this purpose, found them alive after five years, although in the warm climate of Calcutta. The cyclostomas, 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 bulimi, 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 specimens of two Madeira snails (helix paptlio 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 turricula, 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.¢ 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 suryive to re-people | the land and sea abundantly. The spawn of a single doris may contain 600,000 eggs (Darwin); a river-musscl 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. * “Tt was alive 498 days after it was taken from the pond; and in the interim had been only twice for a few hours in water, to see if it was alive."—Rev. W. O. Newnham. + Ann, Nat. Hist. 1850. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 15 Lastly, the mol/usca exhibit the same instinctive 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 bulimzt 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. Ianthina 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 cyclas 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. STRUCTURE 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 moyements. They have organs, by which food is procured and digested; a heart, with arteries and yeins, through which their colourless fluids circulate; a 16 MANUAL OF THE MOLLUSCA. 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 neryes conyey 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 lke 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 breathing in man), without the intervention of the will.* In the mollusca, the principal part of the nervous system is a ring surrounding the throat (esophagus), 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 cesophageal 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 sessile, 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 strombide, the eye is not less highly organised, but in most of the gasteropoda it has a more * See “ Miiller’s Elements of Physiology,” edited by Dr. Baly. STRUCTURE AND PAYSIOLOGY 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 (ocel/i) along the margin of the mantle.* These supposed eyes have been detected in a great Fig. 10. Pecten varius.t many bivalves, but they are most conspicuous in the scallop, which has received the name of argus from Pol 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.{ in each, as in the vestibular cavities of fishes. Similar auditory capsules occur near the base of the tentacles in 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 arrived at by Duvernoy ina " paper in the Annales des Sciences Naturelles for 1852. { fecten varius, L., from a specimen dredged by Mr. Bowerbank, off Tenby ; mz, the pallial curtains; br, the branchie. + Fig. 11. Tentacle of Lolis coronata, Forbes, from Alder and Hancock. 18 MANUAL OF THE MOLLUSCA. © 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. Valenciennes 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, J, 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 mollusca ; it is exercised by the skin, which is everywhere soft and lubricous, and in a higher degree by the fringes of the bi- ments and tentacles (vibracula) Fig. 12. Lepton squamosum.t pedicels of the snail are evidently endowed with great sensitiveness in this respect. That shell-fish / touch is possessed by all the valves (Fig. 12), and by the fila- © of the gasteropods; the eye- — 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 regards the membranous Jamelle between the oral tentacles and in | front of the mouth, as the seat of the olfactory sense. See Fig. 51. Tt Fig. 12. Lepton squamosum, Mont., from a drawing by Mr. Alder, in the British | Mollusca ; copied by permission of Mr. Van Voorst, . as. STRUCTURE AND THYSIOLOGY OF THE MOLLUSCA. 19 inversion 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, 7), 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 (spicula), which renders it a very efficient instru- ment for the enlargement of their cells. (Hancock). In the attached bivalves it is not developed, or exists only inarudi- = Fig. 13. Dreissena.t mentary state, and is subsidiary to a gland which secretes the material of those threads with which the mussel and pinna attach themselves (Fig. 13). These threads are termed the byssus ; the plug of the anomia and the pedicel of terebratula are modifications of the byssus. 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 other 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 Salpa (Hurley); and in Waldheimia australis by Hancock ; a strict search was made by that able anatomist for the purpose of discovering such fibre amongst the hingeless brachiopods, but without success. Striped fibres have been seen in the gasteropods. + Fig. 13. Dreissena polymorpha (Pallas sp.), from the Surrey timber-docks. f, foot ; b, byssus, 20 MANUAL OF THE MOLLUSCA. 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 colwmell/a, 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 * Figo 14. Cytherea chione, L., coast of Devon (original); A, the hinge ligament; u, the umbo; J, the lunule ; c. cardinal tooth; ¢ ¢’, lateral teeth; a, anterior adductor ; a', posterior adductor; p, pallial impression; s, sinus, occupied by retractor of the siphons. — STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 21 palpi, which look like accessory gills (Fig. 18, J, ¢#). The ciliated arms of the brachiopods occupy a similar position (Figs. 4, 5, 6). The encephalous mollusca are frequently armed with horny jaws, working vertically 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 lingual 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 rachis, and the lateral tracts plewre, the rachidian teeth sometimes form a single series, overlapping Fig. 15. Lingual Teeth of Mollusca. each other, or there are lateral teeth on each side of a median series. The teeth on the pleurz 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, { Fig. 15. A, lingual teeth of trochus cinerarius (after Lovén). Only the median tooth, and the (5) lateral teeth, and (90) wnczni of one side of a single row are repre- sented. B, one row of the lingual teeth of cypre@a europea; consisting of a median tooth and three uwncini on each side of it. \ 22 MANUAL OF THE MOLLUSCA, 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 curved, 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 CEE £: KEEEES: Pe aRtoretewrac tt een ae SR a Ts eee CER le i: siffri3 @ Caw 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 bullide 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 plates, so large and strong as to 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 P bivalves contains an instrument called Fig. 17. Gizzard of Bulla.t tho «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 mollusca (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 buccinum undatum (original), from a preparation communicated by W. Thomson, Esq., of King’s College. a, anterior; p, posterior; Z, lateral; r, rachidian. é + Fig. 17. Gizzard of bulla lignarta (original). Front and side view of a half- grown 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 the posterior dorsal side, near the small transverse plate, STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 23 branchs, whose stomachs are often remarkably branched, the liver accompanies all the gastric ramifications, and even enters the respiratory papille 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 -molluses are always furnished with well-developed salivary glands, and some have a rudimentary pancreas ; many have also special glands for the secretion of coloured fluids, such as the purple of the muwrezx, the violet liquid of ianthina and aplysia, the yellow of the bullide, 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 different properties in different 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 Romans obtained their purple dye from three or four species of mollusc, such as murex trunculus, and brandarts, and purpura hemastoma. A few molluscs exhale peculiar odours, like the garlic-snail (helix alliaria) and eledone moschata. Many are phosphorescent, espe- cially the floating tunicaries (salpa and pyrosoma), and bivalves which inhabit holes (pholadide). Some of the cuttle-fishes are slightly luminous; and one land-slug, the phosphoraz, 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 iself, and terminates on the right side, near the head. Occasionally it ends in a perforation more or less removed from the margin of the aperture, as in trochotoma, fissurella, macrochisma, and dentalium, In chiton the intestine is straight, and terminates posteriorly. 24 MANUAL OF THE MOLLUSCA. which are perforated with numerous round apertures. The 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. From 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 cesophagus is partly or entirely surrounded by a venous stnus ; and in the acephala the visceral cavity itself forms part of the circulating system. Aquiferous system. Recent anatomical researches by Messrs. Hancock, Rolleston, Robertson, Williams, and others have thrown considerable doubt upon the existence of any aquiferous system in the mollusca. 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 cypreea, 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. Rolleston and Robertson* there is no con- nection between the blood vascular and the aquiferous systems; _ andthe foot inthe 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 different 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, é 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. ’ a 4 STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 25 ‘a large number of blood corpuscles. This he 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 yery deep water are the lowest in their instincts, and are specially organised for their situation. Some water- breathers require only moist sea air, and a bi-diurnal visit from the tide—like the peri- winkle, limpet, and kellia ; whilst many air - breathers live entirely in the water or in damp places by the water- side. In fact, the nature of the repiratory process is the same, whether it be aquatic or aérial, and it is esserftial 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 (pulmontfera) 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 Fig. 18. Trigonia pectinata.* * Trigonia pectinata, Lam. (original). Brought from Australia by the late Captain Owen Stanley. The gills are seen in the centre through the transparent mantle. 0, mouth ; Zt, labial tentacles ; f, foot; v, vent. Cc 26 MANUAL OF THE MOLLUSCA. round orifice, on the right side of the animal, which 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 brachiopoda, 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 (Figs. 19 and 7). Fig. 19. Bivalve with long siphons.* Those bivalves which have no siphons, and eyen 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. t In some of the gasteropoda the respiratory organs form tufts, exposed on the back and sides (as in the nudibranchs), or pro-_ , tected by a fold of the mantle (as in the inferobranchs and tectibranchs of Cuvier).{ But in most the mantle is ca * Fig. 19. Psammolia vespertina, Chemn. after Poli, reduced one-half. The arrows indicate the direction of the current; 7 s, respiratory siphon ; e s, excurrent siphon , Loot. r + If ariver-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. } t Mr. Collingwood (Annals of Nat. Hist. for 1861), in discussing what function these tufts or papille perform, concludes that morphologically and physiologically they are not branchiz. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA, 27 and forms a vaulted chamber 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 (holostomata) 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 jfissurella, haliotis, and dentaliwm, 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 funnel, 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 vertebrate animals. The respiratory system is of the highest importance in the economy of the mollusca, 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 pointed calamaries, which dart backwards with the recoil, like rockets. C2 28 MANUAL OF THE MOLLUSCA, | ORDERS. CLASSES. Dibranchiata. Owen. Tetrabranchiata. Owen. CEPHALOPODA. Nucleobranchiata. Bl. ENCEPHALA .. .. .4+ Prosobranchiata. M. Edw. Pulmonifera. Cuv. GASTEROPODA. Opisthobranchiata. M, Edw. Aporobranchiata. - Bl. PTEROPODA. Palliobranchiata. Bl. BRACHIOPODA, ACEPHALA.... . .< Lamellibranchiata. Bl. CONCHIFERA, Heterobranchiata. Bl. TUNICATA, The Shell. The relation of the shell to the breathing-organ is very intimate: indeed, it may be regarded as a pnewmo-skeleton, 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 mollusca 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 ewternal when the animal is contained in them, and infernal when they are concealed in the mantle; the latter, as well as the shell-less species, being called naked molluscs. Three-fourths of the mollusca 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 muitivalves 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 cymba (Fig. 20) the nucleus is large and irregular; in y * In its most reduced form the shell is only a hollow cone, or plate, protecting the — breathing organ and heart, as.in dimaz, testacella, carinaria. Its peculiar 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 wholly 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 spiru/a the shell is reduced to this par*. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 29 fusus antiquus it is cylindrical; in the pyramidellide it is oblique ; and it is spiral in carinaria, atlanta, and many lmpets, which are symmetrical when adult. The rudimentary shell of the nudibranchs 1 is shed at an early age, and neyer replaced. In this respect the molluscan 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 wmbo of each valve; it is often very un- like the after-growth, as in wnio pictorum, cyclas henslowiana, and pecten 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 mollusca 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 Minor, there are no mollusca.—(/orbes.) The texture of shells is various and characteristic. Some, when broken, present a dull lustre like marble or china, and are termed porcellanous ; others are pearly or nacreous ; some have a fibrous structure ; some are horny, and others glassy and translucent. The nacreous shells are poe by alternate layers of very thin membrane and carbonate of lime, but this alone does not Fig. 20. Cymba.* ye Fig. 20. Cymba proboscidalis, Lam., from avery young specimen in the cabinet of Hugh Cuming, Ezq., from Western Africa. 30 MANUAL OF THE MOLLUSCA. give the pearly iustre, which 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 margaritifera), and one of the British river mussels (unio margaritiferus). They are also found occasionally in the common oyster, in anodonta cygnea, pinna nobilis, mytilus edulis, or common mussel, and in spondylus geederopus. In these they are generally of a green or rose colour. The pearls found in arca noe 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 furrows formed by the corrugated surface there are a number of fine dark lines (+55 inch apart), which may add to the lustrous effect. In some pearls these lines run from pole to pole ike 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 (Swill origine delle Perle. Translated in Miiller’s Archiv. 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 anodonte) existed most nume-+ © STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA, 31 rously. The most generally prevalent nucleus appears to be the bodies or eggs of minute internal parasites, such as /filaria, distoma, buchephalus, &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. CEH SARS | NW ® ae eo Fig. 21. Pinna. Fig. BS Terebratula, Fig. 23. Pearl. 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.{ The fibrous 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 (pholadide) 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. + Figs. 21, 22, 23.,.Magnified 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. $ They are pink in turbinellus and strombus; white in estrea ; white or glassy, purple or black, in mytilus ; rose-coloured and translucent in pinna.—( Gray.) § The specific gravity of floating shells (such as argonauta and tanthina) is lower than that of any others.—(De la Beche.) $2 MANUAL OF THE MOLLUSCA. 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 brachiopoda 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, 6 the middle, and ¢ the inner stratum ; they may be seen also.in Fig. 25. Hach 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 cyprea, cassis, ampullaria, and bulimus), or longitudinal in the middle layer and transverse in the others (e. g. conus, 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, —(Bowerbank. \t The argonaut-shell and the bone of the cuttle-fish have a peculiar structure; and the Hippurite is distinguished by a ~ LULU WU = = = a Fig. 24. Sections of a Cone.* .* Sections of Conus ponderosus, Brug., 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, f, lines of growth. + 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 Paleozoic fossils are often metamorphic, or have undergone a re-arrangement of their particler, like the rocks in which they occur, STRUCTURE. AND PHYSIOLOGY OF THE MOLLUSCA. Bh) cancellated texture, unlike any other shell, except perhars some of the cardiacee and chamacee. _ Epidermis. All shells have an outer coat of animal matter called the ‘‘epidermis”’ (or 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 ; sometimes it is silky as in helix sericea, or fringed with hairs as in ¢richotropts ; in the whelk and some species of triton and conus it is thick 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 weather 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 leaves, and in fresh-water shells. All fresh waters are more or less saturated with carbonic-acid gas, and in limestone countries 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 wmbones of the bivalves, those being also the parts longest exposed. Specimens of melanopsis and bithynia 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 planorbis sometimes becomes perforated by -the remoyal 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. 34 MANUAL OF THE MOLLUSCA. 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.—( Carpenter.) 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 aviculide and turbinide. 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 © SSS VATU TAOVTYAUUUUY UU Utter a CUMIN 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 STRUCTURE 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 (varix), or of a row of spines, as in tridacna and murex.—( Owen, Grant.) Adult characters. The attainment of the full ee lee to each species is usually marked by changes in the shell. Some bivalves, like the oyster and gryphea (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 : spondylus some parts ofthe mantle F's 76. Section of gryphaa.* secrete more than others, so that cavities, filled with fluid, are left in the substance of the shell. The adult teredo and jistulana close the end of their burrows ; the pholadidea fills up the great pedal opening of its valves; and the aspergilium 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 E 3 Fig. 27. Young is a marvel how they pass in and out, and how Cowry.t they can exclude their eggs (e.g. Pl. 12, fig. 4, anastoma; and Fig. 5, helix hirsuta). * Fig. 26. Sectian of gryphea incurva, Sby. Lias, Dorset (original; diminished one-half) ; the upper valve is not much thickened; the interior is filled with lias, + Cyprea testudinaria, L., young. 36 MANUAL OF THE MOLLUSCA. Yet at this time they would seem to require more space and accommodation in their houses than before, and there are — several curious ways in which this is obtained. The neritidce and auriculide 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 purpure 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 doliwm galea (closely allied to the purpure), 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 secretion 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 dis- solving away the shell. The saliva, however, has no effect on the inside of the shell of the doliwm; indeed, it is said to be unalterable by strong acids. (Monatsberichte der Academie in 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, asin magilus; or it is partitioned off, as in vermetus, © ewomphalus, 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 truncatelle, cylindrelle, and bulimus decollatus ; amongst the fresh-water shells it depends upon local circumstances, but is very common with pirena and cerithidea. a ' Forms of shells. These will be described particularly under — * This is sometimes done by the hermit-crab to the shell it occupies, STRUCTURE AND PHYSIOLOGY OF THU MOLLUSCA. 37 each class ; enough has been said to show that in the molluscan shell (as in the vertebrate skeleton) indications are afforded 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 common -amongst sea-shells. Discoidal shells occasionally become spiral (as in specimens of planorbis found at Rochdale), 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 cayities, or from coming in contact with rocks. The dreissena polymorpha distorts the other fresh-water mussels by fastening their valves with its byssus ; and balani sometimes 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 melanopsis, with whorls ribbed or keeled, as if through the unhealthy in- fluence of brackish water. The fossil périwinkles 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 shells. 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 dextral; 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 helix 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. 88 MANUAL OF THE MOLLUSCA. kind; but the attached valve of chama has its wmbo turned to the right or left indifferently ; and of two specimens of lucina_ childrent 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. voluta 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 spendylus and pecten plewronectes) 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. Terebratula hastata, and some pectens of the car- boniferous period, retain their markings; the orthoceras angu- liferus of the Devonian beds has zig-zag bands of colour; anda terebratula of the same age, from Arctic North America, is — ornamented with several rows of dark red spots. The operculum. Most spiral — shells have an operculum, or lid, with which to close the aper- — ture when they withdraw for shelter (See GASTEROPODA). It is — developed on a particular lobe at the posterior part of the foot, — Fig. 28. Trochus zaziphinus.t * Cameos, in the British Museum, garved on the shell of cassis cornuta, are white — on ah orange ground ; onc. tuberosa, and madagascariensis, white upon dark claret= _ colour ; on ¢. rufa, pale salmon-colour on orange ; and on strombus gigas, yellow on — pink. By filing some of the olives (e.g. oliva utriculus) they may be made into very different-coloured shells, 4 + Trochus ziziphinus, from the original, taken in Pegwell Bay abundantly. This — species exhibits small tentacular processes, neck-lappets, side-luppets, tentacular filaments, and an operculigerous lobe. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 89 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 byssus of the bivalves (Lovén); and in function it is like the plug with which unattached specimens of bysso-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 brachiopoda the separation is horizontal, and the valves are dorsal and ventral. The monomyarian bivalves he habitually on one side (like the plevronectide among fishes) ; and their shells, though really right and left, are termed “upper” and ‘‘lower” valves. The univalve shell is the equivalent of both valves of the bivalve. In the pteropoda it consists of dorsal and ventral plates, comparable with the valves of terebratula. In the gasteropoda it is equivalent to both valves of the conchifera united above.t 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 { 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 back-bone. 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 mollusca 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)— are termed homologous ; those which agree merely in appearance, or office, are said to be analogous. + Compare /issurella or trochus (Fig. 28) with lepton squamosum (Fig. 12). The _ disk of Aipponyz is analogous to the ventral plate of hyalea and terebratula. t The argonaut shell is compared by Mr. Adams to the nidamental capsules of the whelk ; a better analogue would have been found in the raft of the ianthina, which is secreted by the foot of the animal, and serves to float the egg-capsules. 40 MANUAL OF THE MOTLUSCA. with snails (in cool weather) it is generally a degree or two higher. = The mollusca of temperate and cold climates are subject to hybernation ; during which state the heart ceases to beat, respiration is nearly suspended, and injuries are not healed. They also cestivate, or fall into a summer sleep when the heat is great; but in this the animal functions are much less inter- rvpted.—(Miiller.) 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 papilie, 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 diecious) mollusca ; they are united in the (monecious) land-snails, pteropods, opisthobranchs, and in some | of the conchifers. The prosobranchs pair; but in the dicecious | acephalans, the spermatozoa are merely discharged into ‘the: water, and are inhaled with the respiratory currents by the) other sex. The moncecious land-snails require reciprocal union; the lmneids 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 STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 41 in tough albuminous capsules, each containing numerous germs; | these are deposited singly, or in rows, or agglutinated in groups, ) ualling the parent ani- mal in bulk (Fig. 83). The /nidamental capsules of the euttle-fish are clustered jlike grapes, each con- |taining but one embryo; \those of the calamary are jgrouped in radiating masses, each elongated capsule containing 30 or 140 ova. The material jwith which the eggs are | thus cemented together, or jenyeloped, 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 (vitellus), 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 lke itself; it is the essential part of the egg, from which the embryo is formed ; but it undergoes no change without the influence of the sperma- tozoa.t 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 epitheliwm 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{ | . i mm ‘ Fig. 29. Syawn of Doris.* * Nidamentai ribbon of Doris Johnstoni. (Alder and Hancock.) 7 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 two 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! ved According to the observations of Professor Lovén (on pelos bivalve mollusca), € ova are excluded immediately after the inhalation of the spermatozoa, and ently from their influence ; but impregnation does not take place within the itself. The spermatozoa of cardium pygmeum were distinctly seen to pentrate ‘Im succession the outer envelopes of the ova, and arrive at the vitellus, when they dis- ‘Gppeared. With respect to the “germinal vesicle ;*” according to Barry, it first. 42 MANUAL OF THE MOLLUSCA. Up to this 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 sery- 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 » egg. Very little is known respecting the development of Brachio- | pods. F. Muller 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 setze 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 setze, 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 /n several families, so that even in nthe 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- — i 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, Lovén’s account it is said to ‘* burst” and Y 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 resembling it, is seen occupying a small prominence on the surface of the vitelline membrane, until the metamorphosis of the yolk is completed, when it disappears, in some unobserved manner, without fulfilling any recognised purpose. v * Archiv fiir Anatomie und Physiologie, 1860, p. 72; see also Annals of Nat. Hist. for 1860. * mantle. The development of the young has STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 43 similarity, as in the case of the marine and fresh-water forms of the mytilide. The following account refers to the type to which the young of Crenelia belong. At first they have a swimming disk, fringed with long cilia, and armed with a slen- der tentacular filament (flagellum). Ata later period this disk disappears progressively as the labial palpi are 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 been noticed in many of the genera of Pteropods. They are divisible into two groups: those in Fig. 30.* which the body is surrounded with one or more rings of cilia, and those in which these rings are absent. Fig. 30*. Fry of the Mussel. 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; SJ, flagellum ; vv, valves; m, ciliated mantle. 7 F.g. 30*. Fry of mytilus edulis, after Lovén. e, eye; e’, auditory capsule; Z t, 44 MANUAL OF THE MOLLUSCA. hatched, and they enter life under the same form,—that which has been already referred to as permanently characteristic of the pteropoda. (Fig. 69.) . The Pulmonifera and Cepha'opoda produce large eggs, cone 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 bulimus 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 ege. The researches of John Hunter + 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 deyeiopment, 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. From 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 mollusca ; after their first stage they — Fig. 31.* labial tentacles; s s’, the stomach; 5, branchie ; A, heart ; v, vent; J, liver; r, renal organ ; a, anterior adductor; a’, posterior adductor ; 7, foot. The arrows indicate the incurrent and excurrent openings; between which the margins of the mantle are united in the fry. ; * Eog and young of bulimus ovatus, Miill. sp., Brazil, from specimens in the collec- tion of Hugh Cuming, Esq. ; + “In his printed works the finest elements of system seem evermore to flit before him, twice 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 unspokcn — alphabet of nature.”—Coleridge. CLASSIFICATION. — 45 “resemble the simpler orders of their own sub-kingdom, but not ‘those of any other group. These are the views of Professor Owen—the successor of /Hunter—by whom it has been most clearly shown and stead- jfastly maintained, that the ‘‘ unity of organisation” manifested ‘by the animal world results from the design of a Supreme In- j\telligence, and cannot be ascribed to the operation of a mechani- eal ‘* law.” | CLASSIFICATION. The objects of classification are, jirst, the convenient and in- \telligible arrangement of the species;* and, secondly, to afford 2A 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 ofinity ; the second, of analogy. . A finities may be near, or remote. There is some amount of affinity common to all animals; but, like relationships amongst men, they are recognised only when tolerably close. Resem- 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.{ 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. { For example, the paper nautilus, from its resemblance to carinarza, was long sup- posed to be the shell of a nucleobranch, parasitically occupied by the “ ocythoé.” te. g. Aporrhats with strombus, and ancylus with patella. §$ Monoceros imbricatum and buccinum antarcticum take the place, in South America, of our common 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 OF 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 ayail, 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 haye 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 are white and coloured races. The species of some genera are less” subject to variation than others; the nucule, for example, although very numerous, are always distinguishable by good | characters. Other genera, like ammonites, terebratula, 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 form 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 scone more desirable, in the present state of our knowledge, than subdivision into yery numerous families, without gual characters. CLASSIFICATION. 47 The orders and classes of mollusca haye already been Teferred 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 but 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 deriy- able from every part of the animal organisation ; and, as far as their information enabled them, they haye 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 some regular plan, and haye 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 haye ac- cordingly conyerted all the groups into jfives.t 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 effected 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 affinities 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. * The numerical development of groups is wnversely proportional to the bulk of the tudividuals composing them.—( Waterhouse.) _ + The quinarians make out five molluscous classes by excluding the tunzcata ; the ‘same end would be attained in a more satisfactory manner by reducing the pteropods to the rank of an order, which might be placed next to the opistho-branchs. ¢ The quinary arrangement of the molluscous classes reminds us of the eastern 48 MANUAL OF THE MOLLUSCA. " NOMENCLATURE. The practice of using two names—generic and specific—for each animal, or plant, originated with Linnzeus; 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 he os and an opprobrium in all branches ° of natural history.* One very common estuary shell rejoices in the following - variety of titles :— Scrobicularia piperata (Gmelin sp.). Trigonella plana (Da Costa). Mactra Listeri (Awct.). Mya Hispanica (Chemnitz). Venus borealis (Pennant). Lutraria compressa (Lamarck). Arenaria plana (Megerle). As regards s le names, the earliest ought certainly to be adopted, wit wever, the following excaptinaes — 1. MS. names; which are admitted by courtesy. 2. Names given by writers antecedent to Linnzeus. 3. Names unaccompanied by a description or figure. 4. Barbarisms ; or names involving error or absurdity.t It is also very desirable that names having a general (Euro-- pean) acceptation should not be changed on the hecoy ent of earlier names in obscure publications. emblem of eternity—the serpent holding its tail in its mouth. The following diagram @ is offered as an improved circular system :— (FISHES. ] Di-branchiata, Nucleo- Tetra- j Opistho- Proso- ¢/ Aporo- Pulmo- L J Pallio- Lamelli- ei Hetero-branchiata. . [ZOOPHYTES. } * In Pfeiffe~’s Monograph of the Helicide, a family containing seventeen genera - no less than 830 generic synonyms are enumerated ; to this list Dr. Albers, of Bently has added another hundred of his own invention! + This subject was investigated and reported upon bya a committee of the British Association in 1842, | ABBREVIATIONS. 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 haying 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 Linneus or Bruguiere. The “majority of naturalists have disowned this practice, and agreed to distinguish by the addition of ‘‘sp.” the authorities fcr 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. ABBREVIATIONS. % _ Etym., etymology; Syn., synomym ; Did , 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 fins. implies that the genus is found at all depths between low-water mark and 50 fathoms. conica. G. “i —— . insignis. B. ‘ *Nuassa incrassata. F. Hn bicarinata. B. *Buccinum undatum, var. Kara. O. *Natica helicoides. R. G. B. is hyJrophanum, D. Prince |** ,, cjausa, F. N. Zemla. G, Mele Regent Inlet. ville Id. P. Regent Inlet. B. “A tenebrosum. R. G. B. » pallida. R. O. * + Humphreysianum. R. G. » flava. N. Zemla. B. Newf. laa a cyaneum. F. D. G. Icy * 4, pusilla (greenlandica). G. Norway. C,. St. Lawrence. Spitz. ‘ glaciale. Kara, O. C, Parry. nana. G. G. Spitzbergen. *Velutina levigata. R. B. Buecinum angulosum. N. Zemla. Icy | * ,, flexilis. F. C. Spitz. e 4, gzonata. R. G. i tenue. N. Zemla. G. » lanigera. G. ” Groenlandicum. D. Lamellaria prodita. F. a5 undulatum. G. 1) Grenlandica. G. B. ny scalariforme. G. **Scalaria Groeenlandica. F. G. B. a ciliatum. G. ** ,, borealis (Eschrichti), G. ” boreale (Leach). Baffin’s B. Amaura candida. G. 7 sericatum. D. P. Refuge. Chemnitzia albula. G@. ae Hollbéllii (Mangelia, MOl.) |**Mesalia lactea. G. G. F. **Turritella polaris. G, * Dalei. R. Ba Aporrhais occidentalis. Labrador. Pleurotoma, 13 sp. G. *Littorina obtusata. R. *Fusus antiquus. N. Zemla B. * ,, tenebrosa. N. Zemla. D, ee ,, carinatus. G. + Greenlandica. G. F. * ,, contrarius. R. O. * 4, palliata (arctica). G. », Geformis. R. Spitz. a limata. F. ** ,, despectus. G. Spitz, *Lacuna vincta. R. Newf, G. » heros. C. Perry. » labiosa. F. P. Refuge. » latericeus. G. =. 4, . ArIgIde Be * ,, Berniciensis. R. B. » solidula. F, » Spitzbergensis. Spitz. Hydrobia castanea. R. G. * ,, Islandicus. F. Rissoa scrobiculata. G. Foe... SCTACIISC, ©. eG. Bs » globulus. G. **Trophon clathratus. R. G. B. » Saxatilis. G. ** ., scalariformis. Spitz. Newf. B. | *Skenea planorbis. G. F. #% 3) eGunner, 5.) G. ** Margarita cinerea. F, U.S. ** ,, craticulatusy. R. I. G. ae undulata. R. G. i » » Barvicensis. F. ies alabastrum. F. » harpularius. F, U.S. * ,, _ helicina. G. White Sea. Spitz. — * truncatus. » sordida. R, Spitz. G. B. . eSumn lapillus. R. G. B. * umbilicalis. D. B. Mangelia, 9sp. G. ” Hazrrisoni. D. ‘ decussata. D. Ye glauca, G. | *Bela turricula. F. G. 5 Vahlii. G. ; a 5, rufa, (iG. * costulata. G. ; **Mitra Groenlandica. G. *Puncturella Noachina, F. G. **Admete viridula. R. Spitz. G.B. *Acmeea testudinalis. R. Iceland. G. ARCTIC SHELL-FISH. **Lepeta ceca. G, F. Spitz. C. Eden. Pilidium rubellum, F. G. D. Patella, 4sp. G. *Chiton ruber. F. G. Spitz. mys, albus. F. G. Dentalium entale. Spitz. Bulla Reinhardi. G. » subangulata. G. *Cylichua alba. G. F. Spitz. s turrita. G. *Philine scabra. Norway. G. » punctata (Moll.) G. Doris liturata, G, acutiuscula. G. » oObvelata. G, *Dendronotus arborescens. F. G. Z£olis bodocensis. G. Tergipes rupium. G. Euplocaraus Holbdllii. G. *Terebratulina caput-serpentis. Spitz. F. Mass. Medit. *Waldheimia cranium. F. "a septigera. F, Terebratella Spitzbergensis, Sp. = Labradorensis. Labr. **Rhynchonella psittacea. R. Baffin’s Bay, 76° N, Melville, I. B. *Crania ancmala. Spitz. *Anomia squamula. R. * , aculeata. R. **Pecten Islandicus. F. N. Zemla. Spitz. G. B. St. Lawrence. vitreus. F. Arctic America. » Grenlancicus. R. Spitz. D. Limatula sulcata. G. F. *Mytilus edulis. R. G. B. *Modiola modiolus. R. B. *Crenella discors (levigata), G. D. N. Zemla. * » decussata, R. G. * ,» nigra. N. Zemla. R. G. D, ae faba. G. a aviired. .G. Arca glacialis. P. Regent Inlet. Nucula corticata. G. » inflata. G. D. Leda buccata. G. macilenta. G. ” 4. America. > 59 **Zeda minuta(Fabr.) F. Spitz. G. D. ** ,, lucida. F. (= navicularis? Spitz.) * ,, pygmea. G. F. Siberia. **Yoldia arctica Gr. (myalis). G. U.S. Spitzbergen. ** ., lanceolata (arctica B. & S.) Icy Cape. af limatula, F. U.S. Kamt. 44 hyperborea. Spitz. ** ,, thracieformis (angularis). G. Mass. =* truncata, Br. (Portlandica, Hit.) P. Refuge. Arctic America. ** Astarte borealis (arctica). F. Iceland. G. ” ** ,, semisulcata (corrugata). Kara Sea. N. Zemla. Spitz. P. Regent Inlet. C. Parry. Icy Cape. * ,, elliptica. F. G. Spitz. * , sulcata. R. N. Zemla, O. ** ,, crebricosta. F. Spitz. Newf. » crenata. P. Regent Inlet. s» Warhami. Davis Str. » globosa. G, * ,, compressa. N. Zemla. G. »» Banksii, Spitz. Baffin’s Bay. *Cardium edule var. rusticum. R, Islandicum. N, Zemla. &. Greenlandicum, Kara. Spitz, C, Parry. St. Lawrence. ~ aa elegantulum. G. *Cryptodon flexuosus. G. F, *Turtonia minuta. G. F. *Cyprina Islandica. R. Labrador. **Cardita borealis. Mass. O. **Tellina calcarea, F. G. B. ” ¥* o ** ,, Greenlandica, (= Balthica, L.) N. Zemla. Spitz. F. G. B. ** ., edentula. B, *Mya truncata. R. Spitz. G. C. Parry. B. ** ,, Uddevallensis. St. Lawrence. D. P. Regent Inlet. Melville I. * ., arenaria. N. Zemla. G. O. **Saxicava rugosa (arctica). N. Zemla. Spitz. G. C. Parry. B. (Panopea) Norvegica. White Sea. O. Machera costata. Labrador. O. Glycimeris siliqua. C. Parry. Newf. *Lyonsia Norvegica. F. O arenosa. G. D. P. Refuge. * ” ” rostrata (pernula). F. Spitz, Arctic |**Thracia myopsis. G. Pandora glacialis. Spitz. Baff. (Leach). 60 MANUAL OF THE MOLLUSCA. II. Borrat PROVINCE. The Boreal Province extends across the Atlantic from Nova Scotia and Massachusetts to Iceland, the Faeroe and Shetland Islands, and along the coast of Norway from North Cape to the Naze. Of the 289 Scandinavian shells catalogued by Dr. Lovén,* 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 Europe. 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. * British Species. *Teredo navalis. *Lucina borealis. *Pholas crispata. ? =, divaricata. *Solen ensis. *Cryptodon flexuosus. * (Panopea) Norvegica. *Astarte borealis, *Mya arenaria. * ,, triangularis? (quadrans, G.) * ,, truncata. *Cyprina Islandica. *Thracia phaseolina (Conradi, Couth). ? (Cardium Islandicum, U.S.—N. Zemla), Mactra ponderosa (ovalis, G.) Yoldia limatula. ? Montacuta bidentata. » arctica, Gr, (= myalis). *Turtonia minuta. *Leda pygmea. ? Kellia rubra. * ,, caudata, ? Lepton nitidum (fabagella, Conr. ?) ? ,, navicularis (lucida, Lovén ?) *Saxicava rugosa (arctica). *Nucula tenuis. Tellina solidula, var. (fusca, Say). *Mytilus edulis, * , calcarea (sordida, Couth). *Modiola modiolus. * Index Molluscorum Scandinavie; extracted from the “ Ofversigt af K. Vets Akad. Forh.” 1846. The climate of Finmark is much less severe than Russian Lap- | land ; Hammerfest has an open harbour all the year. + Report on the Invertebrata of Massachusetts. 1841. + 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 abound. 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 Scomberoidee (Mackerel-tribe) which feed on the surface, have been previously voted as traversing many Cegrees of longitude in the Atlantic: but the existence of pF the ground-feeding Gadoidee 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, BOREAL PROVINCE. *Crenella nigra. * ,, discors, L. * ,, decussata (glandula, Tot.) Pecten Islandicus. ? Ostrea edulis (borealis, Lam. ?) *Anomia ephippium. ® , aculeata. » squamula? *Terebratulina caput-serpentis. *Rhynchonella psittacea. *Dendronotus arborescens. Polycera Lessonii ? ? Amphisphyra hyalina (debilis ?) Cylichna alba (triticea, C.) -* ,, obtusa (pertenuis). *Philine quadrata (formosa, St.) *Chiton cinereus. * =, | =marmoreus. my ruber. * ~,, levis. * ,, asellus. * , albus. *Dentalium (entale, L. ?) PLepeta ceca (candida, C.) *Acmea testudinalis (amoena, S.) *Puncturella Noachina. * Adeorbis divisus (= Skenea serpuloides). ' Margarita cinerea. 61 *Margarita undulata, * » alabastrum (= occidentalis ?) Littorina groeenlandica. * », tenebrosa (vestita). » palliata? *Lacuna vincta (divaricata). * ,, puteolus (Montagui). *Skenea planorbis. *Velutina levigata, > zonata. *Lamellaria perspicua, *Natica helicoides. » clausa. * 4, pusilla. *Scalaria groenlandica. (Ianthina communis). Odostomia producta, Cancellaria (admete) viridula. *Trichotropis borealis, *Fusus antiquus (tornatus). * ,, island.cus. * ,, propinquus. » ?rosaceus. *Trophon muricatus. * ,, clathratus. » scalariformis. »» harpularius. *Purpura Japillus. *Buccinum undatum. pil te (Cominella) Dalei. *Bela turricula. od » costulata ? (Skenea). <3 Treveryana. * , helicina. * ,, rufa (Vahlii) ? *Ommastrephes sagittatus is also common to both sides of the North Atlantic. The genera, Machera, 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 Forbesi, Strickland, of the Isle of Man; others are marked in the Arctic list. III. CxEttric PROVINCE. The Celtic province, as described by Prof. E. Forbes, 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 Zestacea, A new work on British Mollusca is now being prepared by Mr. J. 62 MANUAL OF THE MOLLUSCA. herring- fisheries) is essentially Atlantic; many of the speci p are of ancient origin, and occur fossil in the Pliocene. The British mollusca described by Forbes 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. 5 (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- luses, 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. Phasianella pullus. Murex corallinus. Cytherea chione. Haliotis tuberculata. Avicula Tarentina, Petricola lithophaga. Truncatella Montagui. Galeomma Turtoni. Venerupis irus. Oncidium celticum. Pandora rostrata. Cardium rusticum, L, (tuber Bulla hydatis. Ervilia 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 being common to N. America. (orbes.) 5 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 4 shell-bearing mollusca were then known, of which 217 or 53 per cent. were common to Scandinavia. 246 or 61 Pe = North of Spain. 227 or 56 a ne S. Spain and Medit. 97 or 24 3 os Canary Islands. gett Shh tee Ee ee ie is 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 O. F. Miiller is still the most important work. bl LUSITANIAN PROVINCE. 63 The following are at present peculiar to Britain :— Assiminea, sp. Odostomia, 19 sp. ? Montacuta ferruginosa. Jeffreysia, sp. Buccinum fusiforme, Argiope cistellula. Otina otis. Fusus Berniciensis. Pecten niveus. Rissoa, sp. » Turtoni. Syndosmya tenuis. Stylifer turtoni. Natica Kingii. Thracia villosiuscula. The most common edible species are :— Ostrea edulis, Mytilus edulis. Fusus antiquus, Pecten maximus. Cardium edule. Littorina littorea. » oOpercularis, Buccinum undatum, Amongst the species characteristic of the Celtic province—or most abundant in it—are the following :— Trophon muricatus, Littorina littoralis. Venus striatula. Nassa reticulata. Trochus Montagui. » casing. Natica Montagui. » millegranus, Donax anatinus, » monilifera. » tumidus, Solen ensis. » Nitida, Patella vulgata. Pholas candida. Velutina levigata. » pellucida. Mactra elliptica. Turritella communis. Acmea virginea, » solida Aporrhais pes-pelecani. Chiton cinereus. Periploma preetenuis. Rissoa cingillus. Scaphander lignariys. § Thracia distorta. Scalaria Trevelyana. Tellina crassa. 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 Littorinz and Limnzans 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. Boll. Buccinum undatum. ~ Neritina fluviatilis, Tellina Balthica. Purpura lapillus. Limnea auricularia. » tenuis. Nassa reticulata. » ovata. Scrobicularia piperata. Littorina littorea. Mytilus edulis. Mya arenaria. Patella (tarentina). Donax (trunculus). », truncata. Hydrobia muricata. Cardium edule var. Meyer and Mobius collected the following species at Kiel :— Chiton cinereus. Rissoa parva. Cerithium reticulatum, Acmea testudinalis. Littorina littorea. Nassa reticulata. Bissoa labiosa. » littoralis. Buccinum undatum. »» inconspicua, Pe tenebrosa. Fusus antiquus. » ulve, Lacuna vincta. » ventrosa, » pallidula. IV. LUsITANIAN PROVINCE. y 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 OF THE MOLLUSCA. weed bank, so as to include Madeira, the 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 Mesalta, occur on the coast of Green- land :— Argonauta. Cancellaria. Auricula. — Philonexis. Sigaretus. Pedipes. Spondylus. Chiroteuthis. Crepidula. Ringicula. Avicula. _—_ Mesalia. Umbrella. Solemya. Conus. Vermetus. Glaucus. Chama. Pleurotoma. Fossarus. a Crassatella. Marginella, Planaxis. Carinaria. Lithodomus. Cymba. Litiopa. Firola. Ungulina. Mitra. Truncatella. Atlanta. Galeomma, Terebra. Solarium. Oxygyrus. Cardita. Columbella. Bifrontia. — Cytherea. Pisania. Turbo, Cleodora,. Petricola. Dolium. Monodonta, Cuvieria. Venerupis. Cassis. Haliotis. Creseis. Mesodesma. Triton. Gadinia, Se Ervilia. Ranella. Siphonaria. Megerlia. Panopea. 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 northern part of the Lusitanian province are the Pilchard fisheries ; in the Mediterranean, the Tunny, Coral, and Sponge fisheries, The Guif-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. (AHum- 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 (iS. 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. vulgare, similar to the varieties of Facus nudosus (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 Alge, Intr. 16, 17.) LUSITANIAN PROVINCE. 65 somewhat northern character, 50 per cent. of them being com- mon to Norway, and 86 per cent. common to the south 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 Columbella cribaria. Of the African shells found here, and not met with in more northern localities, the most remarkable are :— Crassatella divaricata. Ranella levigata. Cymba proboscidalis. Cardium costatum. Cassis flammea, Conus betulinus. Lucina Adansoni. » testiculus. 3» Prometheus. Cerithium nodulosum. Cymba Neptuni. » Guinaicus. Murox 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. »% Natica porcellana. Monodonta Bertheloti. | 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, Verany, 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 Iles Canaries; the list of shells is reprinted, with the additions made by Mr, M‘Andrew, as one of the Catalogues of the British Museum. 66 MANUAL OF THE MOLLUSCA. number of new forms as yet only known in the Mediterranean ; and a few accessions (about 30) of a different character from the Red Sea. The total number of shell-bearing species is esti- mated at 600, viz. :— Cephalopoda .......sseceres 1 Nucleobranchiata... 6 | Lamellibranchiata ......200 PPURTOUOGH Uecnvacassésscosces 13 Gasteropoda ......... 370 Brachiopoda .......sseeeeee 10 On the coast of Sicily, M. Philippi has found altogether 619 marine mollusca, viz. :— DSIVALVOS ca dececwesesspas'’ ste. 188 Pteropoda jecccesskes » 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. *#Rissoa Caspia, Eich. C. » Oblonga, Desm. B. » cylindracea, Kryn. B.* The following species are described by Eichwald, from the steppe limestone. (Murchison, Russia, p. 297.) Donax priscus. *‘ Paludina” Triton. PP exigua. Mactra Caspia. Monodacna propinqua. R': soa conus. » Karagana. “ intermedia. », dimidiatus. Cyclas Ustuertensis. 3 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.t VI. WeEstT AFRICAN PROVINCE. The tropical coast of Western Africa is rich in conchological treasures, and far from being wholly explored. The researches of Adanson,}{ 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. Guinee, coll. Tams. Cassel, 1853. At St. Helena, Mr. Cuming collected 16 species of sea-shells, 7 of them new. Littorina Helene is found on the shore of St. Helena, and LZ. miliaris and Nerita Ascensionis, at Ascension. * The Velutina (Limneria) Caspiensis. A. Ad. was founded on a specimen of Limnea Gebleri, Midd. (1851), from Bernaoul, Siberia. t Aspecies 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. ¢ 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 LINN £US, and employing instead the most barbarous chance-combinations of letters he could invent. § Appendix to Captain Tuckey’s Narrative (1818), by Dr. Leach. 70 Onychoteuthis, 3 sp. Cranchia, 2 sp. Strombus rusaceus. Triton ficoides. Ranella quercina. Dolium tessellatum, Harpa rosea. Oliva hiatula. Pusionella. Nassa Pfeifferi. Desmoulinsia. Purpura nodosa. Rapana bezoar, Murex vifulinus. » angularis. 3» megaceros. 5, rosarius. » duplex. >» cornutus, Clavella? filosa. >» aire. Lagena nassa. Terebra striatula. he ferruginea. ? Halia priamus. Mitra nigra. Cymba. MANUAL OF THE MOLLUSCA, West' African Shells. Marginella. Persicula, Pleurotoma mitriformis. Tomella lineata. Clavatula mitra. ” coronata, 5 bimarginata. Be virginea. Conus papilionaceus. » genuinus. 5, testudinarius. 5, achatinus. s5 monachus. Natica fulminea, Cyprea stercoraria. - picta. Vermetus lumbricalis, Cerithium Adansonii. Turritella torulosa. Mesalia. Littorina punctata. Collonia, Clanculus villanus. Haliotis virginea. » coccinea. Nerita Senegalensis. », Ascensionis. Pecten * bbus. Arca vl T COS. », senilis. Cardium ringens. “e costatun. Lucina columbella. Ungulina rubra. Diplodonta rosea. Cardita ajar. Artemis africana. » torrida, Cyclina Adansonii. Trigona bicolor. » tripla. Cytherea tumens. “f africana, Venus plicata. Tellina. Strigilla Senegalensis, Gastrana polygona. Mactra depressa. » rugosa. » | muda, Pholas clausa. Tugonia anatina. Discina radiosa. VII. Sourn AFRICAN PROVINCE. 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 difficult, 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. va published a very complete monograph.* Of 400 sea-shells recorded in this work, above 200 are peculiar, and most of these belong to a few littoral genera. Only 11 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. South African Shells. Panopea natalensis. Solen marginatus. Mactra spengleri. Gastrana ventricosa. Nucula pulchra, Hinds. (L’Agulhas bank, 70 fm.) - Pectunculus Belcheri, 120 fm. Modiola Capensis. aa pelagica, Forbes. Septifer Kraussi. Terebratulina abyssicola, 132 fm. Terebratella (Kraussia). “: rubra. > cognata. ce pisum. as Deshayesii, 120 fm. Chiton, 16 sp. Patella, 20 sp. » cochlea. » compressa. The following are stated to be common to the Cape and Euro- pean seas.t Saxicava (arctica?) Greenland, Medit. Tellina fabula, Brit. Medit. Patella apicina. » longicosta. » pectinata, &c, Siphonaria, 5 sp. Pupillia (aperta). Fissurella, 10 sp. Crepidula, 4 sp. Haliotis sanguinea. Delphinula granulosa. Fe cancellata. Trochus, 22 sp. Turbo sarmaticus. Littorina Africana 7 sp. Phasianella, 6 sp. Bankivia varians. Turritella, 4 sp. Pleurotoma, 6 sp. Clionello (sinuata). Typhis arcuatus. Triton dolarius. » fictilis, 50-60 fm. Harpa crassa. Cominella ligata. a lagenaria. 9 limbosa. Cominella tigrina. Bullia levissima. », achatina. » natalensis. Nassa plicosa. + capensis. Cyclonassa Kraussi. Eburna papillaris. Columbella, 5 sp. Ancillaria obtusa. Mitra, 5 sp. Imbricaria carbonacea. Voluta armata. » Scapha. » abyssicola, 1382 fm. Marginella rosea. Trivia ovulata. Cypreea, 22 sp. Luponia algoénsis. Cyprovulum (capense). Conus, 8 sp. Octopus argus. Sepia, 4 sp. Chama gryphoides, Medit. Red Sea. Pecten pusio, Brit. Lucina lactea, Medit. Red Sea. » fragilis, Medit. Canaries, Red Sea, Australia ? Tapes pullastra, North Sea. Diphyllidia (lineata?) N. Brit. Medit. Venus verrucosa, W. Indies? Brit. Senegal, Eulima nitida, Medit. Purpura lapillus ?? (not in Medit.) Nassa marginulata. Octopus vulgaris? Brit. Argonauta argo, Medit. »» geographica, Medit. Arca lactea, Medit. VIII. Inpo-Pactric PROVINCE. 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 Red Sea and east coast * Die Siidafrikanischen Mollusken, 4to. Stutt. 1848. { Marks of doubt are added to some of the species, and others are omitted, 72 MANUAL OF THE MOLLUSCA. of Africa to Easter Island in the Pacific, embracing three-fifths of the circumference of the globe and 45° of latitude. 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 Red 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.t 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. t 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 This Europe. Those in italics are also found on the west coast of America. *Nautilus. *Magilus. Stomatella. Hemicardium. *Pteroceras. *Melo. Gena. *Cypricardia. *Rimella. Mitra. *Broderipia. *Cardilia. *Rostellaria, *Cylindra. *Rimula. * Verticordia, *Seraphs. *Imbricaria. *Neritopsis. *Pythina. Conus. Ovulum. *Scutellina. Circe. Fleurotoma, * Pyrula (type). *Linteria. *Clementia. *Cithara. *Monoptygma. *Dolabella. *Glaucomya. ® Clavella. Phorus. *Hemipecten. *Merée. *Turbinella (typ.) Siliquaria, *Placuna, Anatinella. Cyllene. 4*Quoyia. *Malleus. Cultellus. Eburna. *Tectaria. *Vulsella. *Anatina. Phos. Jmperator. *Pedum. *Cheena. Dolium. Monodonta. * Septifer. *Aspergillum. Harpa. Delphinula. *Cucullea. *Jouannetia. *Ancillaria. Liotia. *Hippopus. *Lingula. *Ricinula. *Stomatia. *Tridacna. Discina. The strictly littoral species vary on each great line of coast: for example, Littorina intermedia and Tectaria pagodus occur on * See Mrs. Somerville’s Physical Geography, ii. p. 233. + 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.; Pteurotoma, 100; Mitra, 250; Golumbella, 40; Cyprea, 50; Natica, 50; Chiton, 30; Tellina, 50. ee a INDO-PACIFIC PROVINCE. 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 scabra and H. squamata, in N. Australia; H. asinina, New Guinea; and L. picta, at the Sandwich Islands. Red Sea (Erythreean). Of the 408 mollusca of the Red 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 Red Sea by way of the Medit., probably during the newer pliocene period; the others are Indo-Pacific shells which ex- tended their range to the Mediterranean at an earlier age. The genera wanting in the Medit. but existing in the Red Sea, show most strikingly their diversity of character, and the affinity of the latter to the Indian fauna. Pteroceras. Ancillaria., Siphonaria, Limopsis. Strombus, 8 sp. Harpa. Placuna. Tridacna. Rostellaria. Ricinula. Plicatula. Crassatella. Turbinella. Magilus. Pedum. Trigona. Terebra. Pyramidella. Malleus. Sanguinolaria. Eburna. Parmophorus. Vulsella. Anatina. Dliva. Nerita. Perna. Aspergillum. Other genera become abundant, suchas Conus, of which there are 19 species in the Red Sea, Cyprea 16, Mitra 10, Cerithiwm 17, Pinna 10, Chama d, 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.) Rostellaria curta. Purpura persica. Sigaretus sp. Murex tenuispina var. » carinifera. Odostomia sp. Pisania spiralis. Columbella blanda. Phorus corrugatus. Ranella tuberculata. Oliva subulata. Planaxis sulcata. » Spinosa. » Indusica. © Imperator Saulize. » crumena. » ancillaroides. Monodonta sp. Triton lampas. Cypreea Lamarckii. Halictis sp. Bullia sp. ” ocellata. Stomatella imbricata. Eburna spirata. Natica pellis-tigrina. a3 sulcifera. * The “Brindled Cowry” (Cyprea princeps), from the Persian Gulf, was valued at £50, E 74 MANUAL OF Fissurolla Ruppellii. 5 Indusica, ay salebrosa. “ dactylosa. a funiculata. Pileopsis tricarinatus. Nerita ustulata. Dentalium octangulatum. Ringicula sp. Bulla ampulla. Anomia acheeus. » enigmatica. Pecten sp. Spondylus sp. Plicatula depressa. Mytilus eanaliculatus. Arca obliquata. » sculptilis, &e. Cardium impolituin. “5 pallidum, “5 assimile, Venns pinguis. ssieacOls ;, purpurata. Meroé Solandri. » effossa. Trigona trigonella ? Artemis angulosa, A exasperata. » subrosea? Venerupis sp. Petricola sp. Tapes sulcosa. » Malabarica. Cypricardia vellicata. Cardita crassicostata ? THE MOLLUSCA. Tellina capsoides. Mesodesma Horsfieldii, Psammobia sp. Syndosmya sp. Semele sp. ‘ Solen sp. Solecurtus politus. Donax scortum. » scalpellum. Sanguinolaria diphos, os violacea. 35 sinuata. Corbula sp. Diplodonta sp. Anatina rostrata. Pandora sp. Martesia sp. Pholas australis. Chama sp. » calyculata. >, Bakeri, Desh. Lucina sp. » Tankervillii. » orientalis. Cardium fimbriatum. Mactra Hgyptica, &c. . (Meleagrina Vv. p.416). » latum. Tellina angulata. At the Cargados or St. Brandon shoals, north of Mauritius, Voluta costata, Conus verrucosus, Pleurotoma, virgo, and Turbinella 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., Doliwm galea and Oypreea heivoia, and two of the bivalves, are found in the Mediterranean. TX. AUSTRALO-ZELANDIC PROVINCE. 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, and Forbes.{ Of the following genera some are peculiar (*), others attain here their greatest development :— * Travels in New Zealand, by Dr. E. Dieffenbach. 8vo,, London, 184%, + Moll. Nov. Hollandiz, 1843. + Narrative of the Voyage of H.M.S. Rattlesnake, 1846-50, by J. Macgillivray. applement by Professor E. Forbes. ’ JAPONIC PROVINCE. 75 *Pinnoctopus. * Maccillivraia. Cypricardia. Imperator. *Struthiolaria. *Amphibola. Mesodesma. Monoptygma. Phasianella. *Trigonia. Terebratella, Siphonaria. Elenchus. *Chamostrea. Spirula. Pandora. Bankivia. *Myadora. Oliva. Anatinella. Rotella. *Myochama. Conus. Clavagella. *Macroschisma, Crassatella. Voluta. Placunomia. Parmophorus. Cardita. Terebra. Waldheimia. Risella. Circe. Fasciolaria. Crania. Some of the genera of this province are only met with else- where at a considerable distance :— Solenelia—Chili. Bankivia—Cape. Rhynchonella—Arctic seas. Panopeea—Japan. Kraussia—Cape. Trophon—Fuegia; ,, Monoceros—Patagonia. Solemya—Medit. Assiminea—India; Brit. Amongst the littoral shells of South Australia are Haliotis elegans, H. rubicunda, and Littorina rugosa. Haliotis iris and Littorina squalida are found on the shores of N. Zealand; and Cyprovula umbilicata 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; Strombus troglodytes, Ranella argus, the great Triton variegatus ; 6 Cones (all doubtful), Oliva erythros- toma, Cyprea caput-serpentis, Ancillaria australis, Imperater heliotropium, Chiton monticularis, &e. Venus Stutchburyi and Modiolarca trapezina have been found at Kerguelen’s Id. and Patella illwminata at the Auckland Ids. X. JAPONIC PROVINCE. The Japanese Islands and Corea represent the Japonic pro- vince. Our knowledge of its molluscan fauna is still scanty, notwithstanding the successful researches of Mr. Adams. Up- wards of 130 species were collected in the harbour of Decima, _ Murex eurypterus, a rorifiuus. es plorator. ‘3 Burneti. Trochus, 15 sp. Radius birostris. Cerithium longicaudatum. Imperator Guilfordie. E 2 by Dr. Nuhn, of which 113 were Prosobranchiates. : Octopus areolatus. Purpura, 5 sp. Haliqtis Japonica, Sepia chrysopthalma. Fusus. » discus. Sepiola Japonica. Cancellaria nodulifera. » gigantea, = Mitra. Bulla Coreanica. Conus Sieboldi. Strombus corrugatus. Siphonaria Coreanica. Pleurotoma Coreanica. Cyprea fimbriata, Pecten asperulatus. ' Terebra serotina. is tmhiliaris, » daponicus. ns stylata. Mangelia, 4 sp. Spondylus Cumingii. Eburna Japonica, Triforis, 5 sp. Nucula mirabilis. Cassis Japonica. Natica, 5 sp. 3 Japonica. Cardium Bechei. Crassatella compressa. Diplodonta alata. sa Coreanica. 746 MANUAL OF THE MOLLUSCA. Isocardia Moltkiana. Artemis Sieboldi. - Panopeea Japonica. Venus Japonica, + Japonica, ‘Terebratulina Japonica, Cyclina orientalis. Circe Stutzeri. as angusta. Cytherea petechialis. Tapes Japonica. Waldheimia Grayi. Artemis sericea. Petricola radiata, Terebratella Coreanica. * bilunata. Solen albidus. a rubella. XI. ALEUTIAN 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 (IK), Aleutians and Sitka (S). Patella (scurra). S. Fusus Behringii. Acmea, 3sp. S. 9) seer, As Pilidium commodum. Q, > LUridusy ves Paludinella. 3sp. O. Buccinum undatum var. Schantaricum. Littorina, 6 sp. O. K.S. os simplex. O. Turritella Eschrichtii. O. y Ochotense. Margarita suleata. A. Fi cancellatum. A. Trochus, 6 sp. S. ‘ ovoides. O. © Scalaria Ochotensis. Pisania scabra. A. Crepidula Sitchana. Bullia ampullacea. O. Ae minuta. S. Onychoteuthis Kamtschatica. 4 grandis. A. Fissurella violacea. S. Terebratella frontalis. O. 5 aspera. S. Placunomia macroschisma. O. Haliotis Kamtschatica. Pecten rubidus. S. » aquatilis. K. Crenella vernicosa. O. Velutina coriacea. K,. 7 cultellus. Kamf. » cryptospira. O. Nucula castrensis. S. Trichotropis inermis. S. Pectunculus septentrionalis. A. Purpura decemcostata. (Mid.) S. Cardita borealis. O. > Hreycineti. O.S. Cardium Nuttalli. 8S. * septentrionalis. S. ss Californicum, S, Pleurotoma Schantarica. Saxidomus Petiti. S. of simplex. O. ” giganteus. S. Murex monodon. S. Petricola cylindracea. S. » Jlactica. S. An gibba. S. Fusus (Chrysodomus) Sitchensis. Tellina lutea, A. nasuta. S. » decemcostatus. A. » edentula. A. », schantaricus. - Lutraria maxima. S. The influence of the Asiatic coast-current is shown in the presence of two species of Haliotis, whilst affinity with the fauna of W. America is strongly indicated by the occurrence of Patella (scurra), three species of Crepidula, two of Fissurella, and species of Bullia, Placunomia, Cardita, Saxidomus, and Petricola, which are more abundant, and range farther north than their allies in the Atlantic. ALEUTIAN PROVINCE. 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 the Western Coast of America. _ The mollusca 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 inhabitsthe West Indies, the coast of Panama, and the Gal- 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. Mérch, 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 Veneride in the British Museum ” Artemis angulosa, Philippines—Chili. Cytherea umbonella, Red Sea—Brazil. a 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. } 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 sp.— Siphonaria Lessonii, nearly smooth, Atlantic coast; S. antarctica, ribbed, Pacific coast; and 8. 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 itis 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 Hocene 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 Rocky 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 molluscan fauna of KE. 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 im the British seas. XII. CALIFORNIAN PROVINCE. The shells of Oregon and California have been collected and described by Mr. Hinds,+ Mr. Nuttall,t Mr. Couthouy, natu- ralist of the American Exploring Expedition ;§ Mr. Cooper, Dr. Gould, Mr. Binney,|| Dr. Kennerley, Colonel Jewitt, and others. 4] Shells common to U. California and Sitka. (Middendorff.) Littorina modesta. Trochus ater. Trochus euryomphalus. sf aspera. Rs meestus. Petricola cylindracea. Fissurella violacea. » okkesii. Lutraria maxima, a aspera. * Voyage dans 1’ Amérique Méridionale, 1847, t. v. p. v. + Voyage of H.M.S. Sulphur ; Zoology by R. B. Hinds, 4to. 1844. t Described by T. A. Conrad, Journ. Acad. N. 8. Philadelphia, 1834. id § Gould in Bost. Nat. Hist. Soc. Proceedings, 1846; and U.S. Exploring Exped. MW (Commander Wilkes), vol. xii. Mollusca, with Atlas. 4to, Philad. 1852. , || Explorations for a railroad route from the Mississippi to the Pacific Ocean. 1356. { P. P. Carpenter on Mollusca of West Coast of North America. British Association Report for 1863. PANAMIC PROVINCE. 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; Acmszea, 11 species; Fissurella, 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. Chiton scrobiculatus, &c. Saxidomus giganteus. Murex Nuttalli. Cleodora exacuta. Venerupis cordieri. Monoceros unicarinatus. —— Petricola mirabilis. 33 punctatus. Waldheimia Californica. Mactra, 2. Donax, 1. Cancellaria urceolata. Discina Evausii. Tellina Bodegensis. Trivia Californica. — . sa) HOGla, ieee Natica herculea. Anomia pernoides. Semele decisa. » Lewisii. Placunomia cepa. Cumingia Californica. Calyptreea fastigiata. Hinnites giganteus. Sanguinolaria Nuttalli. Crepidula exuviata. Perna, 1. Pinna, 2. Lutraria Nuttalli. a navicelloides,y Mytilus, 1. Pecten, 2. Platyodon cancellatus. ‘ solida, &c. Mytilimeria Nuitalli. Amphichena Kindermanni. Imperator Buschii. Modiola capax. Lyonsia, 1. Thracia, 1. Haliotis Cracherodii. Chama lobata. Pandora, 1. Saxicava, 2. » fulgens. Cardita ventricosa. Cyathodonta undulata. a corrugata. Cardium, 4. Sphenia Californica. Fissurella crenulata. Lucina, 3. Periploma argentaria. A cucullata. Chironia Laperousii. Solecurtus subteres. Puncturella, 2 sp. Solecardia eburnea. Machaera lucida. Dentalium politum. Venus Californiensis. Ba maxima. Patella, 15 sp. >» callosa. Mya truncata. Acmea scabra. Artemis ponderosa. Panopea generosa. » pintadina. Saxidomus Petiti. Pholas Californica. Chiton Mertensii. b Nuttalli. 3 concamerata. XIII. PANAMIC PROVINCE. The Western coast of America, from the Gulf of California to Payta in Peru, forms one of the largest and most distinct pro- vinees. The shells of Mazatlan and the Gulf have been imper- fectly catalogued by Menke. The Mazatlan mollusks 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 Chitonidz, 13 Acmeeide, 18 Fissurellide, 64 Trochoide, 28 Calyptreeidee, 69 Pyramidellide, 59 Buccinidz, and 90 Muri- cide. The gulf of California, together with the adjacent coast as far as Mazatlan and St. Blas, has yielded 768 shells (502 uni- valves and 266 bivalves), of which 439 also occur in the Gulf of Panama, while 117 extend into 8. America; 635 species are known from the Gulf of Panama; of these, 266 are peculiar to 80 MANUAL OF THE MOLLUSCA. the district, and 163 also occur in 8. America. The fauna of the Panama province is remarkably distinct from the other W. American provinces, and especially the Caribbean. 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 36 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, Hipponyx anti- quatus, Bankivia varians, Natica maroccana, Marginella ceerules- cens, Nitidella guttata, Purpura pansa. Five species are common to Mazatlan and the British coasts, viz., Kellia suborbicularis, Lasea rubra, Saxicava arctica, Cytherea Dione, Hydrobia ulve. 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 Duclosii, Natica maroccana, Nitidella cribaria, Hipponyx barbatus, H. Grayanus, are scattered over the Pacific ocean. The river-openings of this coast are bordered by mangroves, amongst which are found Potamides, Arcas, Cyrenas, Potamo- myas, Auriculas, and Purpuras, whilst Littorinc 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. Gallapagos Islands.—Out of 111 sea-shells collected here by Mr. Cuming, 48 are unknown elsewhere ; 25 occurin Mazatlan, 22 in Central America, 38 in Panama, but only 11 in South America. Littoral shells common to Panama and the Gallapagos (C. B. Adams.} Cyprzea rubescens. Columbella nigricans, Turbinella cerata. Mitra tristis. Ricinula reeviana. Pleurotoma eccentrica. Planaxis planicostatus. Cassis coarctata. Hipponyx radiata. Purpura carolinensis. Oniscia tuberculosa. Fissurella macrotrema, Columbella atramentaria. Conus brunneus. os nigro-punctata. -s bicanalifera. aot UES Siphonaria gigas. 9 hemastoma. Strombus granulatus. Strombus gracilior. Murex erythrostomus. » regius. » imperialis. a5 Wadix. »» brassica. » Mmonoceros, &c, Rapana muricata. » Kiosquiformis, Myristica patula. Ricinula clathrata, Purpura, many sp. Monoceros, many sp. ” brevidentatus. ‘1 cingulatus, Clavella? distorta. Oliva porphyria. » splendidula, &c, Northia pristis. Harpa crenata, Malea ringeng. Mitra Inca, &c. Terebra luctuosa, &c, Conus regularis, &c. Pleurotoma, many sp. Cancellaria goniostoma, ” cassidiformis. s chrysostoma, Columbella, many sp. PERUVIAN PROVINCE. Panama shells. Columbella strombiformis. Marginella curta. Cyprzea nigro-punctata, Trivia. Pyrula ventricosa. Natica glauca. Pileopsis hungaricoides. 81 Pecten macnificus, Arca lithodomus, &c. Pectunculus tessellattis, &c. Nucula exigua. Leda, 5 sp. Cardium senticosum, 35 Mmaculostm, Crucibulum auriculatum, &c. Cardita laticosta. Trochita mamillaris. Crepidula arcuata, &c. Littorina pulchra. Turritella Californica, Truncatella, 2 sp. Coecum, § sp, Imperator unguis, &c. Trochus pellis serpentis, Vitrinella, 12 sp. Nerita ornata. Patella maxima, Discina strigata. - Cumingii, Lingula semen. As albida. » audebardi, Placunomia foliacea, Ostrea equatorialis, Spondylus princeps, Gouldia Pacifica. Cytherea, mary sp. Venus gnidia, » histrionica. Artemis Dunkeri. Trigona crassatelloides, Cyclina subquadrata. Venerupis foliacea, Petricola Californica, &c. Tellina Burneti. Cumingia coarctata. Semele, 7 sp. Saxicava purpurascens, Gastrocheena. Solecurtus lucidus. Lyonsia brevifrons. Pandora arcuata, &c. Pholas melanura, &c. Parapholas. Jouannetia pectinata, XIV. PERUVIAN PROVINCE. The coast of Peruand 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 species (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. Hupé 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. Diphyllidia Cuvieri. Posterobranchea, Aplysia Inca, Tornatella venusta, E3 Onychoteuthis peraptoptera. ZEolis Inca. Doris Peruviana. Chiton, many sp. Patella scurra. Acmea scufum, Crucibulum lignarium. 82 MANUAL OF THE MOLLUSCA. Trochita radians, Oliva Peruviana. Solen gladiolus, Crepidula dilatata. Rapana labiosa. Solecurtus Dombeyi. Fissurella, many sp. Mouoceros giganteus. Mactra Byronensis. Liotia Cobijensis. “4 crassilabris. Mesodesma Chilensis, Gadinia Peruviana. ‘ acuminatus, Cumingia lamellosa. Littorina Peruviana. Purpura chocolata. Semele rosea, &c. a araucana. Concholepas. Petricola, many sp. Rissoina Inca. Mitra maura. Saxidomus opacus, &c. Cancellaria buccinoides. — Cyclina Kroyeri. Sigaretus cymba. Terebratella Fontainei. Venus thaca. Fusus Fontainei. ss Chilensis. Crassatella gibbosa. Murex horridus. Discina lamellosa, Nucula, many sp. Ranella ventricosa. » ° levis. Leda, many sp. Triton scaber. Solenella Norrisii, Nassa dentifera. Pholas subtruncata, &c. Lithodomus Peruvianus, Columbella sordida. Lyonsia cuneata. Saxicava solida, XV. MAGELLANIC PROVINCE. 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 16 species are known from the Malvinas, and 11 of these have 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 pyrifera) 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). Buccinum antarcticum. Monoceros imbricatus. Trophon Magellanicus. es Donovani? ” glabratus, Voluta Magellanica. Bullia cochlidium. “ calcar. » _/enellae * 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 hol? a large Volute, and in T. del Fuego one was seen eating a cuttle-fish.— Darwin. PATAGONIAN PROVINCE. 83 Natica limbata. *Patella barbara. Pecten corneus, Lamellaria antarctica. = Tos) (ZEDERA, Mytilus Magellanicus. Littorina caliginosa. Siphonaria lateralis. * *Modiolarca trapezina. Chemnitzia Americana. Chiton setiger. Leda sulculata. *Scalaria brevis. Doris luteola. *Cardita Thouarsii. *Trochita pileolus. A®olis Patagonica. *Astarte longirostris. Crepidula Patagonica. *Spongiobranchea. *Venus exalbida. Trochus Patagonicus. Spiralis? cucullata, 66° S. *Cyamium antarcticum. *Margarita Malvine. Mactra edulis. *Scissurella conica. Terebratella crenulata. *Lyonsia Malvinensis. *Fissurella radiosa. * ,, Magellanica, many Pandora cistula. Puncturella conica. varieties. Saxicava antarctica. Nacella cymbularia. Waldheimia dilatata. Octopus megalocyathus. *Patella deaurata. Pecten Patagonicus. XVI. PATAGONIAN PROVINCE. From 8. Catharina, 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 labiata, in the valley of La Plata and the Pampas around Bahia Blanca. Mr. Cuming also met with Voluta Brasiliana, 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 Maldonada 37 species were found, 8 being special 10 common to N. Patagonia, 2 to Rio, and 17 to Brazil. Of the latter 8 range as far as the Antilles ; viz. : Crepidula aculeata. Mactra fragilis. Modiola viator. +» protea. Venus flexuosa.* Plicatula Barbadensis. Pholas costata, Lucina semi-reticulata, 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 Brasiliana, ’ Terebra Patagonica. M. D’Orbigny’s list also includes the following genera and species :— | Octopus tehuelchus. ZKolis. Leda. Columbella sertularium, Paludestrina. Cytherea. Bullia globulosa. Scalaria. Petricola. Pleurotoma Patagonica. Natica. Corbula. Fissurellidea megatrema. Chiton, Pinna. Panopeea abbreviata. Solen. Mytilus. Periploma compressa. Lutraria. Lithodomus. Lyonsia Patagonica. Donacilla. Pecten. Solecurtus Platensis. Nucula. Ostrea. * The variety of Venus fleruosa found at Rio can be distinguished from the West Indian shell, which is the Venus punctifera of Gray. 84 MANUAL OF THE MOLLUSCA. XVII. CARIBBEAN PROVINCE. The Gulf of Mexico, the West Indian Islands, and the eastern coast of South America, as far as Rio, form the fourth great tropical region of marine life. mated by Prof. C. B. Adams at not less than 1500 species. The number of shells is esti-. Of these 500 are described by M. D’Orbigny in Ramon 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 R. 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. Argonauta. Ommastrephes. Cleodora. Octopus. Sepioteuthis. Creseis. Philonexis, Sepia. Cuvieria. Loligo. Spirula. Atlanta. Cranchia. Hyalea. Oxygryus. Onychoteuthis. Strombus gigas. 3 pugilis. Murex calcitrapa. Pisania articulata. >» turbinella. Triton pilearis. >, cutaceus. Fusus morio. Fasciolaria tulipa. Lagena ocellata. Cancellaria reticulata. Fulgur aruanum. Terebra avicularis. Mpyristica melongena. Purpura patula. 3 deltoidea, Oniseia oniscus. Cassis tuberosa. » flammea. » Madagascariensis. Columbeila mercatoria. oe nitida, &c. Voluta vespertilio. » musica. Oliva brasiliensis. » angulata. » jaspidea. ay OLY Zi OCG, Ancillaria glabrata. Conus varius, &c. West India Shells. Clavatula zebra. Marginella. Erato Maugerize. Cyprea mus. > exanthema. » Sspurca, &c. Trivia pediculus, Ovulum gibbosum., Natica caurena. Pyramidella dolabrata, Planaxis nucleus, Littorina zic-zac. oy Lea. * lineolata, Tectaria muricata. Modulus lenticularis. Fossarus. Truncatella caribbea. Torinia cylindracea. Turritella exoleta. = imbricata. Trochius pica. Imperator tuber. aE calcar. Fissurella Listeri. + nodosa. ‘9 Barbadensis. Nerita. Neritina. Hemitoma 8 radiata. Cheletropis. Tanthina. Glaucus. Notarchus Plei. Aplysia. Hipponyx mitrula. Pileopsis militaris. Calyptrea equestris. Crepidula aculeata. Patella leucopleura. Chiton squamosus. Hydatina physis. Bouchardia tulipa. Discina antillarum. Placunomia foliata, Plicatula cristata. Lima scabra. Mytilus exustus. Lithodomus dactylus. Arca Americana. Yoldia tellinoides. Chama arcinella. »» macrophylla. Cardium leevigatum. Lucina tigrina. » Pennsylvanica, » damaicensis, Corbis fimbriata. Coralliophaga. Crassatella. Gouldia parva. Venus paphia. » dysera. TRANS-ATLANTIC PROVINCE. 85 Venus crenulata. Artemis concentrica. Strigilla carnaria, 3» Ccancellata, + lucinalis, Sernele reticulata. » vViolacea, Cyclina saccata. » variegata, - Cytherea dione. Trigona mactroides. Cumingia. » circinata, Petricola lapicida. Iphigenia Brasiliensis. 9 maculata, Capsula coccinea. Lutraria lineata, » gigantea. Tellina Braziliana. Periploma inzequivalvis. » flexuosa. » bimaculata. ‘Pholadomya candida, XVIII. Trans-ATLANTIC PROVINCE. The Atlantic coast of the United States was supposed by Prof. E. Forbes to consist of two provinces: (1) the Virginian, from C. Cod to C. 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, 15 being moreover common to Europe. These two regions are sometimes treated of together as the Pennsylvanian province. Dr. Gould 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 levigata, Capsula deflorata.* M. Massachusetts. Y. New York. SC. South Carolina. F. Florida. Conus mus. F, Cerithium ferrugineum, F. Fusus cinereus. M. SC. = 4sp, M. Nassa cbsoleta. M. F. (Mex.) Triforis nigro-cinctus. M. 9 ‘trivittata. M. SC. Odostomia, 6 sp. M. Y. » Vibex. M. F. (Mexico). Turritella interrupta. M. Y. Purpura Floridana. (Mex.) a concava. SC, Terebra dislocata. Y. SC. (Vermetus lumbricalis. M. ?) Pyrula? papyracea. F. Calyptrea striata. Y. Fulgur carica. M. SC. Crepidula convexa. M. Y. » canaliculatum. M, SC, » fornicata, M. F. (Mex), Oliva literata. SC. Littorina irrorata. Y. Marginella carnea. F. Fissurella alternata. (Say) ? Fasciolaria distans. SC. (Mex.) Chiton apiculatus: M. SC, Columbella avara. M. Y. Tornatella puncto-striata, M. Y. Ranella caudata. M. Y. Bulla insculpta. M., Y. Natica duplicata. Y. SC. ; ————— Sigaretus perspectivus. Q. SC. Ostrea equestris. SC. F. Scalaria lineata. M. SC. Pecten irradians (scallop). multistriata. M. Y. Avicula Atlantica. F. - turbinata. NC, Mytilus leucophantus. SC. * The sea-shells, of the United States have also been collected and deszribed by Say, Le Sueur, Conrad, and Couthouy. 86 MANUAL OF THE MOLLUSCA. Modiola Carolinensis. Mactra similis. SC. M. 5 | -plicatulk. Mi. 'Y. ' 4, solidissima, M. Y. Pinna muricata, SC. » lateralis. M. Y. Arca ponderosa. SC. Lutraria lineata, F. » pexata. M.F. » canaliculata. Y. F. » inconyrua. . SC, Mesodesma arctata. M. Y. » transversa. M. Y. Tellina tenta. M. SC. Solemya velum, M. Y. 3 OS8p: SC, ok » borealis. M. Semele equalis. SC. Cardium ventricosum. SC. Cumingia tellinoides. M, ua Mortoni. M. Y. Donax fossar. Y. Lucina contracta. Y. 9s Varlabilis, ‘Gan: Astarte Mortoni. Y. Solecurtus fragilis. M. SC. >» bilunulata. F. - caribbeeus. M. F. Cardita incrassata. F. Corbula contracta, M. F, Venus mercenaria. M. SC. Periploma Leana. M. Y. »» Mortoni. SC. F. ; ” papyracea. M. Y. » gemma, M.Y. Lyonsia hyalina. Y. Artemis discus. SC. Pandora trilineata. M. F. Petricola dactylus. M. SC. Pholas costata. SC. F. pholadiformis. Y. » semicostata. SC. LAND REGIONS. Distribution of Land and Fresh-water Shells. The boundaries of the Natural-history land-regions are more distinctly marked, and have been more fully investigated, than 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 exists 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 moridian ; aud that in passing south- ward, along the three principal lines of land, specific identities = i LAND REGIONS. 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 has its peculiar inhabitants—the survivors, seemingly, 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 attributed to Senegal and China, or Helix similaris Fér. to Brazil and India; and often correctly, but only because they have been carried to distant localities by human agency. Land-snails are in fayour 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. ..0tkWxecse 6 IPIANOIDIS' coeteescccecess 16 Conovulus (Alexia)... 3 Pisi@itm sineeess seeds Ly PAG UU ceecdseces ocsseses i! DYIGSSODR". : .. 0c eserves | According to Reeve, there are 199 British molluscs, of which 176 dwell on the land and 23 in the water. Of the species for- merly thought peculiar, Pupa anglica and Helix fusca have been found 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 polymorpha has been permanently naturalised in canals (p. 424), and Testacella Maugei and haliotidea in gardens; Bu- limus decollatus and Goodalli have been often established in greenhouses. Some species are now very scarce in England that were formerly abundant, as :— Clausilia plicatula, Vertigo Venetzii. Succinea oblonga. 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 § Western Europe autumn rains prevail, and summer rains in Eastern Europe and Siberia. 7 It was the opinion of Professor E. Forbes that ail the species of the Post-pliocene land of Northern Europe and Asia had originated beyond the bounds of that region. 90 MANUAL OF THE MOLLUSCA. Helix fruticum, living in France and Sweden, ng (- DUGEGTAGA Lents -ooee cea Germany. ; », labyrinthica (Eocene) New England. Paludina marginata ......... France. Corbicula consobrina ......... Egypt and India. Unio littoralis cs. seevassecene oe France and Spain. On the other hand, some of the commonest living species have not been found fossil; e.g. Helix aspersa, pomatia, and eantiana. 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), Mogquin Tandon. Dalmatia, 202(197 ,, 5 “n ), Bellotti. Denmark, 95 (72 ,, 238 ‘3 ), Morch. Norway, 52(36 ,, 16 Ace ), Martens and Friele. Finland, 41(23 ,, 26 59 y, Nylander and Nordenskjéld. 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 Germany 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 Limnea palustris, Physa 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. Limnea stagnalis, Bernaul, Irkutsk, » Schrenkii, M. Tunguska, 58°. a palustris, “3 ne » hispida, Beresov. Bernaul. 5 truncatula, ,, Tomsk, » ruderata, Stanowoj Mtn. % leucostoma, Irkutsk. by PULA, s Physa hypnorum, Bernaul; Taimyrlance s, sub-personata, ,,; Ochotsk. Planorbis corneus, Bernaul; Beresov; Pupa muscorum, Bernaul. Kirgisensteppe, Altai. Zua lubrica, 3 Planorbis complanatus, Altai, Succinea putris, 33 Irkutsk. “8 albus, Bernaul, ,, Limnea Gebleri, M. Bernaul. ES contortus, ,, 45 auricularia, Nertschinsk. ro vortex, 3 + ovata, Bernaul. a leucostoma, ,, - Kamtschatica, Mid. : nitidus, Irkutsk. Bs peregra, Bernaul, Beresov. Bithynia tentaculata, Bernaul, ' LUSITANIAN REGION. 91 Bithynia Kickxii, R. Ami, Altai. Anodon anatinus, Tunguska. Valvata cristata, var. Sibirica, Bernaul, Fe cellensis var. Beringiana, Kamt- Beresov ; Kamtschutka. schatka, A piscinalis, R. Ami. Cyclas calyculata, Bernaul, R. Lena, R. Unio complanatus Kamtschatka, Ami, 8. Kamts, »» Dahusicus, Mid. Schilka. Pisidium fontinale, Beresov. » Mongolicus, M. Gorbitza, Dauria. “ obliquum, Bernaul,.Tomsk. Anodon herculeus, M, Scharanai. 2. LUSITANIAN REGION. The countries bordering the Mediterranean, with Switzerland, Austria, and Hungary, the Crimea (Zaurida), and Caucasus, form a great province (or rather cluster of provinces) to which Professor E. Forbes apphed 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 Helicide.t Of the 12 species of Zonites (proper) 10 are peculiar to Lusitania. The species of Bulimus, Achatina, and Pupa are small and minute, belonging to the sub-genera Bulimulus, 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 Cyclostomide and 44 Limacide :— RS eee Wsdsd'S.ct sales i 392 ViGnines Sos05 sexes sos tee 11 Cryptellayiceresesseneees 1 PRUNES occ aececesess0 80 Daudebardia............ 3 Cyclostoma ............ 5) RHICCINGH,. oes .<.csceseee 8 Helicolimax ..::........ 3 Craspedopoma ......... 3 PRGMALIND occ ccecescssese 25 LR So ecsve a aeences 28 (POM AtIASHR scat ecst he: 10 Tornatellina ............ 3 ATION: Seve eiaenvatenesgee 7 (A CiCUIND 22st edosdea tee 4 Balea........-- dan esenasevias 4 IPHOSpHOEAS: 2bs ncas ods os 1 -—— MPR es oxesst cde dscane cde 120 Dy Pestaeellawes. oy szye. <4 2 Caryehiuna, --...20.-<. 3 UC, 247 Parwiacetlas:... asc. 5 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, Lithoglyphus, and Cyrena. Melanopsis buccinoides 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°. { The writer is greatly indebted to W. H. Benson, Esq., for information respecting the land-shells of the Lusitanian province, Africa, and the remote islands. ¢ Many of these cannot be considered species, in the sense here understood, bu‘ only as races, or geographical varieties, 92 MANUAL OF THE MOLLUSCA. Syria, having become extinct in the intervening countries. Two species of Lithoglyphus inhabit the Danube; Cyrena (Corbicula) Panormitana is found in Sicily, two others in the Euphrates, and C. consobrina in the Alexandrian Canal. The Lusitanian province includes numerous minor regions, the islands and mountain tracts especially being centres or /foct where a number of peculiar species are associated with those living around. Thus, of species not as yet recorded from other > antiquorum, » pisana. Bulimus decollatus. » agrestis. »» Dulchella. » ventrosus, Fer. » gagates. » lenticula. Balea perversa (p. 293). Testacella Maugei. (,, lapicida, fossi). Limnea truncatula. ay haliotidea. Cionella acicula. Ancylus fluviatilis. Great quantities of dead shells of the land-snails are found in ancient sand-dunes near Canigal, 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 two almost inaccessible spots on the north coast of Madeira; it is not a native of the Canaries, 94 MANUAL OF THE MOLLUSCA. Extinct Land-snatls of Madeira, Helix delphinula, Lowe. M. » arcinella, Lowe. P. » coronula, Lowe. S. Deserta. vermetiformis, Lowe. P. Lowei, Fer. (porto-sanctana, var.?). P. fluctuosa, Lowe (= chrysomela, Lowe). P. » psammophora, Lowe (phlebophora var. ?). P. » Bowdichiana, Fer. (punctulata, major ?), M. P. Glandina 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 eyi- ‘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 rure.t 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 Isiands 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, i Pupa 5, Limax1, Phosphorax 1, Testacella 2, Oryptella1, and — * See the observations of Mr. James Smith, and of Sir C. Lyell and Mr. Hartung (Geol. Jour. 1854), + 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 neighbouring islands it exceeds 100 inches, i LUSITANIAN REGION: 95 4 Cyclostomide. 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. Heliz 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 haye 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 Verde; the mean temperature is 65°—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 Distribution. Helix amanda, Sicily—Palma, » Planata, Morocco—Canaries. » lenticula, S. Europe—Mudeira—Canaries. », rozeti, Sicily, Morea—Algeria—C. de Verde—Canaries. », lanuginosa, Majorca—Algeria—Palma. », simulata, Syria—Egypt—Lancerotte. » Michaudi, summit of Porto Santo—Teneriffe ? 3» eyclodon, Azores—Canaries—C. de Verdes. » advena, (= erubescens Lowe), Madeira—Azores—St. Vincent. »» pliearia and planorbella, Canartes— Porto Rico? 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 Helicide 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 MANUAL OF THE MOLLUSCA, i to) «cae volcanic. The indigenous plants are all peculiar, and not more ~ related to those of Western Africa than to Brazil.* The land 3 shells are also peculiar; 13 species have been described, viz. -— ¥ “_ Helix,” sp, Bulimus 5, Achatina 2, Pupa 1, Succinea (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.t+ Bulimus auris vulpinus. Bulimus relegatus. 55 Darwini. Helix bilamellata. a Blofieldi, »» polyodon. 4 Sealei. » Sspurca. = subplicatus. » biplicata. . terebellum. » 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 Plecochilus, Pachyotis and Caprella have been given), including B. signatus, B. bilabiatus, B. goni- ostomus, and especially B. sulcatus (Chilonopsis, Fischer) of St. Jago.{ 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 * “Tt 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, vr on anyother — part of this coast of Africa.””—R. Brown, Appendix to Captain Tuckey’s Narrative of the Congo Expedition (p. 476). 1818. + G. Sowerby in Darwin's “ Volcanic Islands,” p. 73. Forbes, Journ. Geol. Soc, — 1852, p. 197.—Benson, An. Nat. Hist. 1851, vii. 263. ¢ As Dr. Pfeiffer includes this (with a sign of doubt) amongst the synonyms of B. auris-vulpinus, he must have suspected that the specimens came from St. Helena and not from St. Iago. The only other group of Bulimi resembling the St. Helena | shells occurs in the Pacific Islands:—Bulimus Caledonicus at Mulgrave I., B. auris zovine at the Solomons, and B. shongi in New Zealand, CAPE REGION. 97 continents than now maintains is dimly indicated. The infor- mation we have obtained respecting the extinct and existing terrcstrial mollusks would seem to point in the 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 @ 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 REGION. Tropical western Africa, with its hot swampy coasts and river valleys is the region of the great Achatine and Achatina-like Bulimi, 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 Recluziana inhabits the Guinea Islands. Helix Polini, Bulimus numidicus and 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 (Zanistes) is generally diffused in the fresh waters of Africa; several species of Potamides and Vibex 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 parasiticum, Egypt. Iridina exotica, Senegal. Cyrenoides Duponti, Senegal. “A rubens 39 Corbicula, 4 sp. Egypt. Pleiodon ovatus By Iridina nilotica AXtheria semilunata ,, Nile. oa aegyptiaca “ bs Galatea radiata = 4, CAPE REGION. 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 and pulchella) probably imported to the environs of the Cape. In 1863 they had raised the number to about 90. There are also 3 slugs, 9 freshwater Pulmonifera, 7 marine Pulmonifera, 5 freshwater bivyalyes, and 5 univalyes. F 98 MANUAL OF THE MOLLUSCA. The species found at the Cape, Algoa Bay, Natal, &c., are for the most part different—Potamides decollatus, Clionella sinuata, and an Assiminea inhabit brackish waters. SEAS Ben vsyteaiesssccen) | — — PANU OM tacts ces cesecbacacess 1 MAUISIN YOR ae. sakesscecttes UPL. PAINGING ie eere cage eeses 3 — PHYSA....00.0.cc0000 00. 4 NORMA. .carpaeeenee 1 PITA ays cade eessveececs 4 Physopsis ......... Ka teats 1 oe SET ESIERS ES ereatcesinwave aontie 35 Arey] UB ve 2: 3.0 Esede vost ek 1 Corbiowla ...scsssssssue ui SHUCOINGD viccecevencrnve,) 4 PlQNOLDIS ise.eecvconees, © .-CYCIRS a raeeaeeeenenenen 1 MVTIEIIVIS cs caace ceckeas«s 13 — Pisidium' 25. y: mucronata. » fusus. » aurantiaca. » ditella, » sulcata, » Toultilivata. sil BOE » Clavulata. » @xXpansilabris. 3 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, Bourbon (No. 33). Helix czlatura. Helix tortula. » detecta. » Brandiana. »» delibata? Pupa Largillierti—Mauritius. Rodriguez. Cyclostoma articulatum, Madagascar ? Streptaxis—pyriformis., No. 34. Kerguelen’s Land. WHelix Hookeri was collected at this island when visited by the Antarctic Expedition. 6. INDIAN REGION. Proceeding eastward, in Asia, the species of Achatina, Pupa, Clausilia, Physa, 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 Helicide and 50 Cyclostomide., A very F2 100 MANUAL OF THE MOLLUSCA, few of the Indian species are common to China and the 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 AsiaticIslands. In the Himalaya land shells are numerous, and ascend as high as the region of Junipers and Rhododen- - drons, 4,000—10,000 feet above the sea. EIGN RAeractccsencseth ease 83 UDB jectnassesscpisetecada 7 Cyclophorus .......0000- 26 INATIITIR ys escencass’:s 000 40 Clausilia: (ec vccccsaescse, 10 Leptopoma eccsccnes I Ariophanta ........ ... 8 VatEING ccs csccaleasaancs 9 Pterocyclusjessnasssee eh RMLCWIARIS ..sascesasese00 3 SUCCINES, J. sascaccsseseccy aul Cyclotus.. vesccatacastets 3 PS TITATS casas conesses ve 49 Parmacell a 1 Helicinga; . csivatensec 6 The Island of Guam, Ladrones, has 3 sp, of Partula, 2 of Achatinella, and 1 Omphalotropis. At the Marquesas haye been found 3 sp. of Nanina, 1 Partula, and 1 Helicina. NEW WORLD. 16, CANADIAN REGION. 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 afew 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 ( Calluna 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 cellaria (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. » tavus, New York, introduced. Vitrina pellucida (= Americana ?) Limnea palustris (= elodes, Say ?). Arion hortensis, New York (Dekay.) » truncatula (= 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 :— GI Ais s fee gaests eae. URT YEG. ‘Cylindrella i..0.c0css 20 Megaloma...........000- 2 Achatina (Spiraxis) ,. 35 §- Cyclotus ...ssccceeeee 1 Belicing “Aci.ncan 22 Amongst the fresh-water shells are Neritina picta, Cyclas maculata, Corbicula convexa, and 7 species of Cyrena. From Mazatlan, Mr. Carpenter describes Cyrena olivacea and Memicana, Gnathodon trigonus, Anodon ciconia (allied to the Brazilian A. anserina), Physa aurantia and elata, Planorbis sp. Melampus olivaceus. Two brackish-water species, Cerithidium varicosum and Montagnet, are common to South America. 21. ANTILLES. The West Indian Islands have supplied nearly 500 species of Helicide, a larger number than any province except the Lusi- tanian ; and above 260 Cyclostomide, 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 mean temperature of the Antilles is 59°—789, and the annual fall of rain exceeds 100 inches in most of the islands. 18 IG) Eb. Sr ae een BOO! Ho DENI B bs « cay op oss apres Bd 26 Cyclophorus .......0006 1 SECMOPUS | ;...accscessecse 25 POylindrella’.....ccc01.06 73 Cyclotus eittwedee qeoos LE BARB ri iii sinicst cae. detsow 200 Clansilla f. cveasdgises 1 Megaloma.......... ve 8 Proserpina.......s0.s000 PaO as isd sa Raws ence 1. Helicing,....dsss.a-sepuae PSTEITNUGSs syucsee sea thsss ee 63 = Succinea. ......:. Fences 16 = - Aloadig...... csi 17 A CHAUING * i cecsthe snobs 27. ~~ Chondropoma ......... 16-~ Lrochatell#’ ...cacnsst 16 Glanding: ....kicdccaie. 46 Choanopoma............ 638 =—s- Lucidella .....s..00% PE PIPERS es srevsdveodesivsie 9. Adamisiella csv 10 =—-—- Stoastoma ..s.......sse00 20 Tornatellina ........5... 1 CBE istic uéssissschsas 36 Geomelania ...... Prenye tt 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, Adamsiella, Jamaica, Chondropoma, COLUMBIAN REGION. 111 part, and Cistula, part.)* The solitary Clausilia is found in Porto Rico, the Balea in Haiti, and the Tornatellina in Cuba; Stenopus 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 Achatine belong to the sub-genera Glandina, Liguus and Spiraxis ; the Bulimi are sharp-lipped and mostly small and slender (Subulina, Orthalicus). Helix (Sagda) epis- tylium, H. Carocolla, and Succinea (Amphibulima) patula are characteristic forms. Although connected with Florida 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 Limacide are represented by Vaginulus (Sloanei) ; and in the fresh waters there are species of Physa (3), Planorbis (8), Ancylus, and the peculiar Gundlachia, Valvata pygmea, Am- pullaria (fasciata), Paludestrina (minute species), Hemisinus, and 2 species of Pisidiwm. In the brackish waters are Cerithidium, Neritina (e.g. melea- gris, pupa, virginea, viridis), Melampus (coniformis), and Pedipes quadridens. 22. CoLUMBIAN REGION.f The tract shaded in the map comprehends several 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; 8, the Guianas, including the Valley of the Amazon, where the forests are most luxuriant, and rain falls almost daily (amount- ing to 100 or eyen 200 inches in the year). Most of the low lands, like those of the Mexican Province, belong to the ‘‘ Cactus Region” 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. + In 1821 the States of New Granada, Venezuela, and Ecuador united to form the ’ * Columbian Republic,” but dissolved again in 18381. 112 MANUAL OF THE MOLILUSCA. Helix .....s00 Sean tice ds ADs 0: PROB iascadtheinnssnantled 7 -Cistald is: bojadietven om Streptaxis ............... SD gM BRIAR cthis a xsncuenup's 4 Bourciera ........ ee BUMS c.i..:6..00..8. 200 Cylindrella .........0. 1 “Cyclotys” .cecssseee 8 PUCCINI Nessie. ovivee ses OEP WAGER nekincs ucoeaene 1 “Adamsiellat.t.scneecas 1 Tornatellina............ 1 AAMAS PEs dase ossbeates 1 Helicingt.. scciiiaeees 6 PCHATIOB cis ssissscvnvse' 10 Choanopoma............ 2. -)"Trochatellajy. screen 1 Glandina ....... ieseexes 5 Cyclophorus ..........4. 2 The presence of several species of the 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 afforded 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 Miilleria, representing the African 4ftheria, inhabits the Rio 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. achatinellinus. 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. 377.) 23. BRAZILIAN REGION. The ‘‘ region of Palms and Melastomas,” extending from the Amazon to the southern tropic, is one of the richest zoological provinces. Itincludes 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. Clausilie 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. PERUVIAN REGION. 113 others dry, rocky and rainless, especially in the south; it is watered by numerous streams—the affluents of the Amazon and Plata. The hydrogravhical 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 severai species of Helix up to the elevation of 14,000 feet; Bulimus Tupaici ranges to 9,000 feet. The large and typical species of Bulimus belong to this province; B. ovatus 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 (Obeliscus), 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 Cyclostomide are few, and the other West Indian forms have almost disappeared. SEMEN, w syckestadeasesesece 47 GIANGING: 2. scsccecossess 1 Cyclophorus ............ 2 PMTOPtAKIS J. 2c0.cessecees ll Tornatellina............ 1 Cyclotus? os. chtsersecs 1 Anastoma .......0s.0000. 7 WWaAtTIN AN 2.5 oSa2002<082522 5 Cistylla! 1.6i. cee: 1 EATININS..2s-2cccvcneseses 250 OmalonyX............008 I So Heliciia, .2.5/raes— Genera which attain their mazima in the present seas are thus expressed —=aj + Land and fresh-water shells of existing species are found with the fossil bones of the Mastodon and Megalonyz, in N. America. (Lyell.) t 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 Phillips has discussed this subject in his work on Devonian fossils (p. 165), and in the “Guide to Geology.” G 122 MANUAL O# THE MOLLUSCA. ‘* Echini are most common in the superior strata; ** Ammonites to those beneath ; ‘* Producti, with numerous Encrini, to the 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 differ 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 sufficient 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 :—Palzeozoic, 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. * The Pliocene 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 sn additional **‘ Formation,” much less a ‘‘ Quaternary System.” + It was on this account that Professor Sedgwick proposed the term “ Palseozoic,”? rather than “ Protozoic,” for the oldest fossiliferous rocks, TABLE OF CHARACTERISTIC GENERA. 123 It. TABLE OF CHARACTERISTIC GENERA. ——_——. SYSTEMS. GENERA AND SUB-GENERA. Camaroceras, Endoceras, Gonioceras, Pterotheca. 1, CAMBRIAN, or Maclurea, Raphistoma, Holopea, Platyceras. Lower Silurian ..... Orthisina, Platystrophia, Porambonites, Pseudo-crania. Ambonychia, Modiolopsis, Lyrodesma. \ Actinoceras, Phrigmoceras, Trochoceras, Ascoceras. ETD REAN ssccccsevess < Theca, Holopella, Murchisonia, Atrypa, Retzia. Cardiola, Clidophorus, Goniophorus, Grammysia. Bactrites, Gyroceras, Clymenia, Apioceras, Serpularia. Se DEVONIAN ....c000000. - Spirifera, Uncites, Merista, Davidsonia, Calceola. / Stringocephalus, Megalodon, Orthonota, Pterinea. \ Nautiloceras, Discites, Goniatites, Porcellia. 4, CARBONIFEROUS... Naticopsis, Platyschisma, Metoptoma, Productus. } Aviculo-pecten, Anthracosia, Conocardium, Sedgwickia. Camarcphoria, Aulosteges, Strophalosia. 5. PERMIAN ............ + Myaling, Bakewellia, Axinus, Edimondia. 6. TRIAS Ceratites, Naticella, Platystoma, Koninckia, Cyrtia. peal sseeeeee* 1) Monotis, Myophoria, Pleurophorus, Opis. 7. L. JURASSIC Alaria, Trochotoma, Rimula, Pileolus, Cylindrites. Waldheimia, Thecidium, Spiriferina, Ceromya. Gryphza, Hippopodium, Cardinia, Myoconcha. ek Leptoteuthis, Nautilus. {siti Beloteuthis, Geoteuthis, Ammonites. Spinigera, Purpurina, Nerinza, Neritoma. Pteroperna, Trichites, Hypotrema, Diceras. lrigonia, Pachyrisma, Sowerbia, Tancredia. SU SORASSIC . 5.0000 ‘ Crioceras, Toxoceras, Hamulina, Baculina. 9. L. CRETACEOUS ... | 5 Reguienia, Caprinella, Sphera, Thetis. Belemnitella, Conoteuthis, Turrilites, Ptychoceras. Hamites, Scaphites, Pterodonta, Cinulia, Tylostoma. 10, U. CRETACEOUS ... ‘a Globiconcha, Trigonosemus, Magas, Lyra. Neithea, Inoceramus, Hippurites, Caprina, Caprotina. Volutilithes, Clavella, Pseudoliva, Seraphs, Rimella. LL, EOCENE «.....+..000 Conorbis, Strepsidura, Globulus, Phorus, Velates, Beloptera, Lychnus, Megaspira, Glandina, lee u ‘sem Volvaria, Lithocardium, Teredina. Spirulirostra, Aturia, Vaginella, Ferussina. Halia, Proto, Deshayesia, iso, Cassidaria, Carolia. Grateloupia, Artemis, Tapes, Jouannetia. 922 MIOCENE, .cicccccecee Argonauta, Strombus, Purpura, Trophon. 13, PLIOCENE............ Yoldia, Tridacna, Circe, Verticordia. g 2 124 MANUAL OF THE MOLLUSCA, III. RANGE OF GENERA IN TIME. Genera, arranged in their Order of Appearance. Cambrian. Silurian. Devonian. Carbonif. Permian. L. Jura U. Jura, L. Cret. U. Cret Eocene Miocene. Pliocene Lituites, Raphistoma, Obolus ..............+ —— Camaroceras, Atrypa, Pterinea ............ —_——— Gomphoceras, Bellerophon, Pentamerus | — — — — Oris,’ Conularia, Murchisonia...........-->< |— ——-— == Spirifera, Athyris, Posidonomya...... ..... | ———— — | == PSGATOW sccces winscccbessscassestevessecdetcnuesseas | == aes = a rr Conocardium, Megalodon, Chonetes ...... —_ Cardiomonphe? }) tates a ios aeieeei aecn tok -—-—-—— Orthoceras, Loxonema, Cyrtia.........5...++ _ Pleurotomaria, Porcellia ...............sec0e0 os Productus, Macrochilus, Streptorhynchus —_-_— Goniatites, Pleurophorus ...........seceeee0es MOmOondia, MYALMA.....<...cccccs sere ssecncotve -_-— ACUCODING |, 5. nuspeactestn sabasaciscdodosscsessteeee tt la)! t= —— Kees Terebratula, Pinna, Cyprin@.....c.0008008. ) ——_a | loo LATIN yc ec teece us Wada dvt vate eseck iat sb uokvahostis —|———-——-—}/--— Goorvallia, MiyOCOnChai tes... veccssevasacsacetees —|-—-—-—-——-—— AnimonttessNaticella, Opis V6....8. 84 Oe eee Trigonia, Isocardia, Thecidium Cerithium, Plicatula, Cardita:,.......0.4 0.0. 4———— =e Trochotoma, Tancredia, Gryphea ......... Ancyloceras, Inoceramus, Unicardium ... — Astarte, Pholadomya, Corbis .........000.f § | ————|——— Nerinza, Goniomya, Exogyra ............06. Terebratella, Limopsis, Neera,Argiope... | | ———j——— Baculites, Cinulia, Radiolites ............... -— Physa, Paludina, Unio, Cyrena Aporrhais, Tornatella, Pyrula ............... Pectunculus, Thetis, Crassatella ............ CTenOlLA “CHAIN sostoncees capeueceaskcke Soncetey NS Voluta, Conus, Mitra, Haliotis, &c.......... BA CUTHUD Peter rec tahe ti tess Mee cles cy teikuces ——- Helix, Auricula, Cyclostoma ............... ae Pseudoliva, Rostellaria, Seraphs sete eee wees POPPUTE, MULOMMDUS!s /ecseccscccssecdesceeeseccecs a VATGONGULEA, UTIGACNAD \secsessescesvervcessevevess — The genera of the older rocks are believed to be nearly all extinct; for although the names of many recent forms appear in the catalogues of Palzeozoic fossils, it must be understood that they are only employed in default of more exact infor- mation. Buccinwm, 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- stoad. RANGE OF FAMILIES IN TIME. 125 IV. RANGE OF FAMILIES IN TIME. Systems of Strata. Cambrian. Devonian. Carbonif. Permian Miocene, Pliocene. Argonautide Teuthide—Sepiade Belemnitide Nautilide Ammonitide Orthoceratidee Atlantide—Hyaleide Strombide—Buccinide Conide—Volutide Naticide—Calyptreide Pyramidellidz Cerithiade#—Littorinide Turbinide—lIanthinide Neritidee—Patellide Dentaliade Chitonidee Terebratulide Rhynchonellide Spiriferide—Orthide Productidze Pectinide Aviculide—Mytilide Arcade—Trigoniade Unionide Chamide—Myadz Hippuritide Tridacnidz Cycladide Cyprinidze—Anatinide Astartidz Distribution of Families of Shells in Time.—Employing the term *‘familes” 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. :— Belemnitide. Spiriferidee. Hippuritide, Ammonitidez. Orithide. : Orthoceratide. Productide. 126 MANUAL OF THE MOLLUSCA. Three others are nearly extinct :— Nautilide. Rhynchonellide. Trigoniade. And several have passed their maximum, and become less varied and abundant than formerly, e.g.— Tornatellide. Cyprinide. Anatinide. The extinct families and genera appear to have attained thei. — maxima 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 Palseozoic families disappear, twenty-six others replace them in the Secondary series; and three of the latter are succeeded by fifteen 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. From 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 Paleozoic 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 Paleozoic, 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. DISTRIBUTION OF MOLLUSCA IN TIME. 127 DEVELOPMENT OF FAMILIES, GENERA, AND SPECIES, IN TIME. ala] =| PS Sarit ies Total . GEOLOGICAL re 2) a1 8 | S || numberof | 3 SYSTEMS. Goneal a |elals Species FS e “| 5 3 4 = D'Orbi = e121 Ss |S | @orbgny)-| 3 eee eee = Sy 4 §Cambrian.................. 4g | 12] 11 ul 362 (| 18 = Oy ee 53 | 138) 13 317 20 g Pee PGVONIAN'.¢...<.0<00cs0cess 17 14 | 20 20 1035 24 +32 4 | gf Carboniferous............ 19 11 | 26 23 835 30 x Ee... fo 0 eensesode 66 6 | 24 20 74 30 5S Sen si | 9| 25 31 713 | 35) 2! g Win SUPARSIC) 2222. -2.secseee 107 12 | 35 48 1502 42 a NJAC UTARGIC <25...,50ccese0 108 13 | 36 50 1266 49 +57 Sl ¢ L. Cretaceous............. 123 20 | 41 53 784 52 3 U. Cretaceous............ 148 16 | 59 59 2147 56 n ——— —|-———— Sanna a I EOCENE .......eeseereeeeeees 172 4 | 85 Ge 2636 60 < ) 7< Miocene ...........000++ 178 3 t97 16 2249 60 3} 12 Dee 1G oe eee 192 1 {160 | 12 | 79 437 62 778 = NREGOMU cc ccctitescss cavecens 400 21 \251 | 13 1115 16,000 78 <) | a, |= eee = Recent & Fossil......... 520 56 |280 | 34 |150 30,000 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 palzeozoic 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 oy 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.t 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 as *hose actually found in it. We have left this table as it stood in the first edition, as we are unable to correctallthe figures. This, however, is not of much importance, since the main points, such as the gradual increase in the number of families, would not be affected. . + The Paleoteuthis of Bronn (not D’Orb.) appears to be a fish-bone, from the equ'vae ent of the Old Red sandstone in the Eifel. 128 MANUAL OF THE MOLLUSCA. (Orthoceratide and Belemnitide) were respectively the first de- veloped. Amongst the Brachiopoda the hingeless genera attained their maximum in the paleeozoic 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 their maximum while the TJerebratulide were still few in number. The subdivision with calcareous spires disappeared with the Liassic period, whereas the genus Rhynchonella still exists. Lastly, the typical group, Terebratulide, 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 palzeozoic formations contain numerous genera of all the families with an open mantle; Cyprinide, Anatinide, 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 are represented in the palzeozoic strata by several genera closely allied to the diminutive Atlanta and Scissu- rella, and by others perhaps related to Zanthina. The Naticide and Calyptreide are plentiful, and there are several genera of elongated spiral shells referred to the Pyramidellide. 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 Pulmonifera 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 Hocene 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 hypothesis seems to have arisen out of an exclusive regard to the poverty of the Permian and Triassic strata in England, where they separate, like a desert, the paleeozoic from the “* neozoic”’ formations. The *“* Permian ”? should never have been esteemed more than a division of the carboniferous system, and is poor in species, rather 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 MOLLUSCA IN TIME. 129 and habit 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 first developed are most like the embryonic forms of their respective groups, and the progression observed is from these general types 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 diffused from common centres, and that the barriers which now divide them haye 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.+ 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 Lepadida, were the last to appear. The fossil mammalia afford, however, the most remarkable examples of thislaw. At the present day such an animal as the three-toed horse (Hippotherium) of the Miocene Tertiary would be deemed a dusus nature, but in truth the ordinary horse is farmore 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 several distinct 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 to indicate the prevalence of deep water in the primeval seas. G3 130 MANUAL OF THE MOLLUSCA. been thirty times submerged, and has formed part of the 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 diffusion 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 interyal 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 of genera and 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, viz.— Pecten polymorphus, a Medi- terranean shell; and Lutraria rugosa, still found on the coasts — of Portugal and Mogador. i 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 eatinct species. — And the newest of these, in Britain, contain an assemblage of — Northern shells. Professor Forbes has published a list of 124 DISTRIBUTION OF THE MOLLUSCA 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 Crag, a few extinct species are found (e.g. Nucula Cobboldic, Pl. 17, f. 18). At Chiliesford, Suffolk, Yoldia arctica and myalis occur of large size and in excellent preseryation, with numerous specimens of Mya truncata, erect as they lived, in the muddy sea-bed. Trophon scalariforme, Admete viridula, Scalaria groen- landica, and Natica grenlandica, also occur in the Norwich Crag ; and Astarte borealis, with several arctic forms of TJellina, are amongst the commonest shells, and frequently occur in pairs, or with their ligament preserved; the deposit is extensively quarried for shell-sand. Raised sea-beds with Arctic shells at Uddevalla, in Sweden, have been repeatedly noticed ever since the time of Linnzeus. Captain Bayfield discovered similar beds near Quebec, 50—200 feet above the River 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.t 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 Lajonkairii, Chama gryphoides, and species of Cassidaria, Cleo- dora, Sigaretus, Terebra, Coluwmbella, and Pyramidella. It also contains a few forms belonging to an earlier age—a Pholadomya, a true Pyrula,a Lingula, 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. + 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 efficient and probable cause would be a diversion of the Gulf-stream, which he supposes to have flowed up what is now the valley of the Mississippi. (Geological Journal). 132 MANUAL OF THE MOLLUSCA. The shells of the newer tertiaries are always identical, at least generically, with those of the nearest coasts. Thus, in Pata- gonia are found species of TZrophon, Crepidula, Monoceros, Pseudoliva, Voluta, Oliva, 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 be all of recent species, but on comparison prove to be mostly distinct. The proportion of extinct species in the Pliocene tertiary varies from 1—d0 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 Hocene 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—Rostellaria, Oliva, Ancil- laria, and Vulsella, genera still living in the Red Sea; and many species of Nautilus, Rimella, Seraphs, Conus, Mitra, Pyrula, Phorus, Liotia, Cardilia—genera characteristic of the Indian Ocean; Cyprovula, Typhis, and Voiutilithes, now living at the Cape ; Clavella, at the Marquesas, and Pseudoliva, 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 (mumia), a Cyclotus (with its operculum) like C. Jamaicensis, and the little Helix labyrinthicus. Secondary Age.—In none of the older strata do we find indica- tions of a warmer climate haying 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 Red 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 [chthyo- saurus were found at Exmouth Island, the farthest point reached by Sir E. Belcher’s expedition. DISTRIBUTION OF THE MOLLUSCA IN TIME. 1338 The peculiar physical conditions of the Chalk period are represented at the present day, not so much by the Coral Sea, as by the A!gean, 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 Reptiles” by Dr. Mantell, who compared the state of England at that time with the present condition 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 7’rias, 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.* Paleozoic Age.—It has lately been shown by Professor Ramsay that signs of glacial action may be traced in some of the trappean conglomerates of the Permian and of the Devonian or Old Red Sandstone period in England ; and Mr. Page has endeavoured to apply the same interpretation to phenomena of a similar cha- racter in the Old Red sandstone of Scotland.t Geologists gene- rally haye 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 palzeozoic 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.{ If such exist, to shadow the Paleozoic 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 the a Zealand, since the Triassic period. + See also the Rev. J. G. Cumming’s “Isle df Man” (1849), p. 89 t Views of Nature, p. 221. Bohn’s ed. 134 MANUAL OF THE MOLLUSCA, ~~ nay, often seemingly producing results opposed to @ prior probability, and at variance with the suitableness of con- ditions ?* The answer is, that each fauna bears, above all things, the impress of the age to which it belongs. Hach 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 mollusca 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. Recent. Fossil. Recent. Fossil. CEPHALOPODA. Dibranchiata. Weritidee 2c. sdeeseeseer 428 103 Argonautide ............ 4 2 Patellidee ....:..ss0005, 868 104 Octopodida...ccrcesevsens 63 _ Dentaliadee:..<. dos. a. 3 0 IV. DALGM Teisy ieShe cess) stow ly. 1855. Locality ... ... ... Vigten Island (N. Drontheim). Distance from shore ... Quarter of a mile. Depth 6 Vee. 6 shes. 0 tathome: Ground... ... ... ... Coral-bank. Arca nodulosa... 3 5 Leda caudata... 2 0 Yoldia lucida ... 3 0 Astarte succata : 3 4' Pecten Islandicus ... 0 2! Lima excavata 0 1 Lucina Sarsii ... 0 1 Cryptodon flexuosus 2 0 Modiola phaseolina Aa 10 0 Anomia ephippium doo bas “enc Many. 0 Venus ovata : 0 2 Terebratulina caput- serpentis 20 Many. Chiton asellus.. ; 33 4 0 Puncturella noachina ... 2 0 Emarginula fissura 1 2 aa crassa’... 0 1 Margarita cinerea... ... 1 0 7 alabastrum ... 1 0 Trophon barvicensis 1 0 i, & Water | ..1@e... sce... UME 2drd5 1855. Locality... ... ... Ommaesie ( Nordland), Depth ... ... ... ... 80 to 50 fathoms. Distance from shore... Half a mile. Ground... ... ... ... Stones and sand, Na. OF fa 0.4 Fours Saxicava arclica 6 2 Tellina proxima 0 1 Venus ovata ... 2 0 Small. Cyprina Islandica .. nde 2 Many. e Astarte elliptica ... 0... wes aa 0 9 compressa.. whined 6 0 Cardium fasciatum =... 2 0 i BHECICUML..6 vee (ade 5 4' Modiola phaseolina see tes 200 f Many. Large. Crenella nigra... .6 02 ose 0 1 _ Large. Nucula nucleus... ans ses 0 | 5 ay, LEEDS set Wea wen fae) ase 4 | Many. TieGS CAUGATSnccumsstiniess: Since) More 2 0 Arca pectuncwoides ... ... 12 | 10' Large. DISTRIBUTION IN DEPTH. 147 Number Number Species. of living of dead Observations, specimens. | specimens. Pecten striatus 2 0 SeetprTinus: <2. 3 6 Se MIS... a6 1 0 | » . Islandicus ... v0 l' | Large and Recent. Terebratula cranium a4 80 10 : Terebratulina caput-serpentis a 1 0 Crania anomala os + 12 0 i Many stones had on them the attached valve. Chiton Hanleyi 3 0 Lepeta ceca ... + 0 Acmea virginea ... 10 6 Pilidium fulvum ™... Many. 4 Puncturella noachina ... 2 1 Trochus millegranus 2 0 Eulima polita... 1 0 Natica nitida ... ... 3 2 >, helicoides ... 0 1 9 pusilla .. 0 1 Velutina levigata .. 1 0 Trichotropis borealis 6 3 Large. Nassa incrassata 1 0 Fusus antiquus 0 2 Carinated Var. Trophon clathratus... 0 1 Mangelia turricula... il 0 Tornatella fasciata 0 2 Buccinum undatum 6 0 Young. Pleurotoma nivalis... 10 15 VI. Date July 20th, 1855. Locality North of Rolphsoe (Finmarken). Depth ... ... 130 to 180 fathoms. Distance from shore .. Half a mile. Ground:.. o.6 .. similis... 0 l Arca pectunculoides 1 0 Syndosmya prismatica... 0 1 Cryptodon flexuosus 0 1 Mactra elliptica 0 2"6" Cardium fasciatum 0 2 7 ~ BUCCICUM... . .<- 0 3 Astarte sulcata ... ... i. I 0 Anomia ephippium ner ows Many. 0 Crenella decussata... 2 Many. sais ( BICTA.. ae Boe 0 2! Terebratula cranium ... ven 3 0 Rhynchonella psittacea... ... 1 2 Dentalium entule ... ... 4... Many. Many. Puncturella noachina ... Many 0 Dbepetacoeca 236. sib. ccs Vieke 2 0 Pleurotoma nivalis... ... 0... 1 2 148 MANUAL OF THE MOLLUSCA. Number Number , Species, of living of dead Observations. specimens. | specimens. Fusus? sp... 0 Fry. Buecinum Humphreysi sianum 0 1 Bela turricula .. ot 2 0 Margarita cinerea . 3 4 “A undulata 0 2 aS alabastrum .,.. 0 1 VII. Date . duly 25th, 1855. Locality Off the Island of Arnée (Finmarken). Depth ... ... 200 fathoms, Distance from sire Four miles. Ground... Mud. Pecten similis... Cryptodon flexuosus Neera cuspidata Arca 3 aa Nucula tenuis .. Yoldia lucida... ... Modiola phaseolina Cardiura suecicum.. Crenella decussuta... Astarte crebricostata Terebratula cranium Dentalium aa ass ” a ” quinguangilare (Forbes) Eulima bilineata ... Eulimella Scille Mangelia trevelliana Bela rufa “se Philine quadrata pes DREDGING PAPERS, Date Locality e ‘ Distance from shore ... Depth ... Ground... Pinna squamosa Modiola tulipa... ... Pecten polymorphus » hyalinus OR ' CSCOCONFPRFRrROCOCOFrNN RNY CHRO 2 0 1 3 0 6 0 0 0 4" 2 2 8 0 2 3 il 1 uh RECORDS OF RESEARCHES IN THE AGEAN SEA. By PrRoFressor EK. ForBEs. oe Nucula margaritacea . 2 Cytherea chione 5 venetiana es apicalis ,, I. May 29th, 1841. Nousa Bay, Paros. Within the Bay. 5 to 6 fathoms. Mud and sandy mud. 0 In sandy mud, In dark mud, MH ROORRRO DISTRIBUTION IN DEPTH. 149 Uy oS EES ee nee EEEEEaAEEEtine Number Number ; Species. of living of dead Observations. specimens. | specimens. Artemis lincta 0 i Tapes virginea 0 5’ Venus verrucosa 0 5! Tellina donacina 0 1-3! > balaustina... 0 2' Syndosmya alba 0 2-10! Lucina lactea... ... 0 2-28 » squamosa ... 0 3' SRE TOLHTIGOLS, & acy i neon sce 0 4' Cardium rusticum... ... ... 0 iy A strong valve. » @Xiguum ... 3 (4 Cardita sulcata ce aes 0 1 Patella scutellaris... ... 0 1 Washed in from shore. Calyptreea Sinensis eevtbaxess 0 2 Bulla hydatis .... ..8 ... 0 jl Turritella 3 plicata... a 0 1 Trochus canaliculatus ... ... 0 4 SSQIMAUITN FIR, 6k ace ce 0 3 2 vulgatum 12 8 Murex fistulosus 1 0 In dark mud. Aplysia depilans ... 1 0 Ostreea plicatula 0 10' } ET. WIAEGS Piice eae cca sce Ept. Léthy 1842 Locality ... ... ... Gulf of Smyrna, Depts e.6-%..- ... 26 fathoms. Distance from shor’ Two miles and a half, Ground... ........... Fine brown mud. Avicula Tarentina... ... ... 3 3 Full grown, adhering. to each other. BIRNEY GLCHCS, «cod vee, vey (vse; 4 0 Fit. SAO | icc Gee. coe ses =AUOUSt ath, 184th. Locality... ... ... Off northern extremity of Paros. Waepthh <2 200. ss saee, 40 fathoms. Distance from shore... Three miles and a half, GNOUNG.. 5 06. | van oss. | WROOdY: Pecten pusio ... ... » opercularis... Nucula margaritacea Cytherea apicalis ... Cardita squamosa ... ... 0 ses see Cardium papillosum ... ws s. Fusus fasciolaroides Murex brandaris Vermetus gigas in COTDEUS) ..i5) - dd MY, Trochus CXiZ NUS): ese) coe eee eve Turbo rugosus.. ve Pleurobranchus ‘sordidus ... Doris tenerrina ... ... . yo QTACHIS 0. ee ee cee wee - RR SEP Ca Ascidium, four species Aplidium, two species 4’ 1 Small. New. New. CoonorWwWON New. New. RPNNwRKERKwDWWoororceoot 150 MANUAL OF THE MOLLUSCA. IV. Datel sca shure. Sept. 16th, 1841. rinse gee ees Off Ananas Rocks. 1072) 0) 01 aes 105 fathoms. kound... sar Visee! weve INIUOre. Distance hesh eneeh. From Rocks three miles, from Milo ten miles. Number Number , Species. of living of dead Observations. specimens. | specimens. Terebratula vitrea ... 0 2! Dead and worn, Megerlia truncata ... = 80 100-20' Of all ages. Argiope decollata ... “ 100 400-6’ Of all ages. = seminulum ee 18 10-8’ Morrisia anomioides “he 1 0 Adhering to T. vitrea. ; New. Crania ringens one 0 om Lima elongata ‘ 0 BY New. Pecten concentricus 0 1' New. » fenestratus... 0 2' New. Spondylus Gussoni... 1 iy Area lattea ... .. 1 ail 5, scabra 0 oF Neera cuspidata 0 iv » attenuata 0 1’ New. Fusus echinatus 0 2 Pleurotoma crispata 0 2 Hitherto known only fossil. ~ maravione... 0 2 New. abyssicola SAC 0 4 New. Mitra ‘philippiana es 0 4 New. Cerithium lima 0 8 Trochus tinei ... ... 0 6 - exiguus 1 9 Turbo sanguineus ... 0 24 Hitherto known only fossil in the Medi- terranean basin. Rissoa reticulata 4 11 Emarginula elongata 0 8 Pileopsis Hungaricus 0 1 Small. Acmea unicolor 1 24 New. Atlanta Peronii... 0 2 Incrusted with nul- lipore, and thus rendered solid. Hyalea gibbosa 0 1’ Cleodora pyramidata 0 3 Criseis clava ... 0 7 » Sspinifera 0 10 ¥. DSC aes se) ese nse Mov. 25th, 1841, Locality... S. extremity of Gulf of Macn, Depth ... i. 230 fathoms. Distance from shore ... One mile (shore steep). Ground... ... . Fine yellowish mud. Terebratula vitrea ade ih eee 0 2" Syndosmya profundissima ... ... 0 3! Arca imbricata ia 1 1 Dentalium quinquangulare ... |. 1 0 Hyalea gibbosa ... ... ... . 0 1 Cleodora pyramidata ... ... ,. 0 8 tt) 5 Criseis spinifera ... eee DISTRIBUTION IN DEPTH. 151 The distribution of the Mollusca 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. 8. The Coralline zone, from 15 to 50 fathoms. 4. The deep-sea coral zone, 50 to 100 fathoms or more. 1. The 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, Zutraria 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. Cyprea and Conus shelter under coral-blocks, and Cerithium, Terebra, 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 (Laminaria) and other sea-weeds form miniature forests, the resort of the vegetable feeding mollusks— Lacuna, Rissoa, Nacella, Trochus, Aplysia, and various Nudibranchiata. On soft sea-beds bivalyesabound and form the prey of Buccinwm, Nassa, and Natica. From 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 Ovulwm and Purpura, browse on the flexible Gorgonie. 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 commr-~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 MOLLUSCA. 3. Coralline zone.—In northern 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, Pleurotoma, Natica, Aporrhais, Philine, Velutina ; and by vegetable feeders, such as /Fissurella, EHmarginula, Pileopsis, Eulima, and Chemnitzia. The great banks of scallops belong to the shallower part of this region, and many bivalves of the genera Lima, Arca, Nucula, Astarte, Venus, Artemis, and Corbula. 4. Deep-sea Coral-zone.-—From 50 to 100 fathoms the Nullipore still abounds, and small branching corals to which the Tere- bratula 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, Dentaliwm, and Scisswrella. In the mud brought up from deep water may be often found the shells of Piteropoda, and other mollusca which live at the surface of the sea. In the Agean 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. Gould (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 from 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 DISTRIBUTION IN DEPTH 153 rare Panopeea Norvegica are swallowed, and ejected again with eroded surfaces. The haddock swallows shells still more indis- criminately, and Mr. 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 :— Norway. (M*‘Andrew.) Aigean. (¥orbes.) Living shells. Living. Dead. Fathoms. | Murex vaginatus......... 150 Cerithium metula .............6.... 20—150 | Fusus muricatus ......, ». 80—95 150 Margarita cinerea ............ceeees 10—130 | Nassaintermedia......... 45—185 Dentalium entale .............s000s 200 | Cerithium lima............ 3—80 140 A RANGEL edifssui es cbse. caeb ooasye 120 | Chemnitzia fasciata ... 110—150 TGR PYOTMCA ..5.52:cncebiscesocsensy 200 | Eulima distorta ......... 69—140 HOVOM URAL, cds .sssenscnceoeess}s 120 | Scalaria hellenica ...... 110 Thetis koreni ................0000058, 40—100 | Rissoa reticulata......... 55 185 Cryptodon flexuosus vis.esiceeeeees 200 | Trochus exasperatus ... 10105 165 Scissurella plicata ...... 7O—150 Off the Cape. (Belcher.) Acmea unicolor ......... 60—105 150 Buccinum? clathratum ,........... 136 | Denialiam quinquangulare 150—230 Volutilithes abyssicola ........... ‘ 132 | Bulla utriculus ............ 40—140 Pectunculus Belcheri..,........... é 120 | Spondylts Gussonii ... 105 Pecten Hoskynsii_..... 185—200 Zgean. (Forbes.) Arca imbricata ............ 90230 Living. Dead. | Nera cuspidata ......... 12—185 Terebratula vitrea ..:......... 100 250 | Thetis anatinoides ...... 40—150 Argiope decollata ............ 100 110 | Kellia abyssicola _...... 70—180 200 Crania ringens ..........sss0000. 90 150° Syndosmya profundissima 80—185 Preserving molluscous animals for ecamination. When shell-fish are killed by sudden immersion in hot water or strong spirit, great and unequal contraction is caused, d's- 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 (Ophiocoma) are killed by sudden immersion in fresh-water; and the Actinie may be stupified 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 their irritability, and contract slowly and completely, when placed in spirit, H3 154 MANUAL OF THE MOLLUSCA lingual teeth; 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. Goadby’s solution is prepared by dissolving 4 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. Burnet’s 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 Calciwm 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 Silliman’s Journal, July, 1854.) PART Ii. SYNOPSIS OF THE GENERA. CHAPTER I. OLASS I.CEPHALOPODA. THE cephalopoda are represented by the common squid, the nautilus, and the ammonite; forms with 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 gradatiwnal 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 strueture 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 the 156 MANUAL OF THE MOLLUSCA. 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. Inall 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 mollusca, 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 branchice. ORDER I.—DIBRANCHIATA, Owen. Animal swimming; naked. Head distinct. Hyes 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; branchie 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 modern 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 two 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 ; yiz., powerful arms, furnished with suckers ; the * According to the established usage, we designate that the under 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 gasteropods, 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 secretion of an inky fluid, with which 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 acetabula) form a single or double series on the inner surface of the arms. From tne 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-bag (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 (Cicero), and in the preparation of sepia,t 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 theskin. 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, ke 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 (‘‘ nuchal”) 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, with 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 its circular web.” — Owen. t Indian ink and sepia are now made of lamp-smoke, or of prepared charcoal. 158 MANUAL OF THE MOLLUSCA. times free all round, and it is supported only by cartilaginous ridges, fitting into corresponding grooves, and allowing con- siderable freedom of motion. eet se 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 land. They attain occasionally a much greater size — than any other mollusca. 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.* From 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.—OCTOPODA. Arms, eight; suckers sessile. yes 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 differ from the typical cuttle-fishes in haying 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 purpose of helping forward the work of reproduction of the species. In many cases it is so f altered as to be incapable of acting as a locomotive organ. — According to Dr. Miiller, 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 scu'tling a three-master, told M. Defrance that if this were “ swallowed,” he would in his next edition represent the monster embracing the Straits of Gibraltar, or capsizing a whole squadron of ships. (D’Orbigny). CEPHALOPODA. 159 for a parasitic worm; and more recently it has been regarded as the 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, Pl. I. The body is worm-like, with two rows of suckers on the ventral 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, 1m 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 yein on each side, giving branches to the branchial filaments, while a nerve runs down the centre. The ovul 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 of trichocephalus acetabularis ; it was again described by Costa,* who regarded it as ‘‘a spermatophore of singular shape;”’ and lastly by Dr. Kolliker.+ 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 branchice ; the skin contains numerous 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 haye 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. Sc. Nat., 2nd series, 7, p. 173. + Lin. Trans., vol. 20, pt. 1, p. 9; and in his own zootomical Berichte, where it is figured. t An. Se. Nat., 2nd series, vol. 16, p. 185. 160 MANUAL OF THE MOLLUSCA. certain parts of the palpi of the males are developed into spoon- shaped organs which perform the same office 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 young argonaut bas no shell. M. Duvernoy has shown that the embryo argonaut has acquired a shell before it has been excluded from the egg. 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 flattened 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. 35. Development of the Cuttle-fish. (Kdlliker). A, Embryo two lines in diameter; m, mantle; 4, branchial processes; s, siphonal processes; a, mouth; e, eyes; 1—45, rudimentary arms. B, 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 body (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 the © 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 epipodiwm ; their * Entwickelungs-geschichte der Cephalopoden. Zurich, 1844. CEPHALOPODA. 161 anterior ends are continuous and attached; the posterior ends are at first free, but eventually uniting they form the funnel ps. The rudimentary gills b appear between the epipodium and mantle. The alimentary canal is at first straight; (the mouth being at a, the vent at b, in Fig. 35 A). The embryo now grows faster in a vertical than in a longitudinal direction, so that it takes on the cephalopodic 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 Fig.36. Argonaut, embryo horny and transparent. The lateral ange 2 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; b the gill; and m the mantle. FamMity I.—ARGONAUTIDA. Dorsal arms (of the female) webbed at the extremity, secreting asymmetrical inyoluted 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 ARGONAUTA, Lin. Argonaut, or paper sailor. Etymology, argonautat, sailors of the ship Argo. Synonyms, ocythoé (Rafinesque). Nautilus (Aristotle and Pliny). ~ 162 MANUAL OF THE MOLLUSCA. ne ee Example, A. hians, Soland. Pl. II., Fig. 1. China. The shell of the argonaut is thin and translucent; it is not moulded on the body of the animal, nor is it attached by shell- — muscles; and the 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- / Vig. 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 Zanthina. 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 Fig. 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 lke a snail. (Madame Power and M. Rang.) 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 * From a copy of Rang’s figure, in Charlesworth’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. - + Poli has represented it sitting the opposite way; the writer had once an argona) shell with the nucleus reversed, implying that the animal had turned quite round in it shell, and remained in that position, The specimen is now in the York Museum. CEPHALOPODA 163 the rest is free and coiled up. It has 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 irom the stomach of a dolphin caught upwards of 600 leagues from land. Fossil, 2 species, Tertiary. A. hians is found in the sub- apennine tertiaries of Piedmont. This species is still living in the Chinese seas, but not in the Mediterranean. Famity IJ.—Ocropopip#. Arms similar, elongated, united at the base bya web. Shell represented by two short styles, encysted in the substance of the mantle. (Owen.) Octorus, Cuvier. Poulpe. Etymology, octo, eight, pous (poda), feet. Synonyms, cistopus. (Gray.) Example, O. tuberculatus, Bl., Pl. 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 cayities 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 MANUAL OF THE MJULUSCA, quires great force to remove them. At other times 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 EK. 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 moredeyeloped than — the corresponding arm on the left side, and terminates in an oval-shaped plate (Fig. 38, Cc), 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 tothe 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- Fig. 38. Octopus carena @, Ver. ure or Het showing cyst in place of p erate.-and tropical zones; 46 B, Ventral side of an individual more species. are known; when developed, with the Hectocotylus C. adult they vary in length from 1 inch to more than 2 feet, according to the species. Sub-genus. Tremoctopus (Chiaje), Pl. I., Fig. 3. Name from two large aquiferous pores (¢remata) on the back of the head. d Pf * « Journal of a Voyage round the World.” The most fascinating volume of travels published since Defoe’s fiction. ) é iH i M4 bs CEPHALOPODA. 165 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. Pinnocrorvus, 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 ELEepDoNE. (Aristotle.) Leach. Type, EK. octopodia, L. Suckers forming a single series on each arm; length 6 to 18 inches. . Moschata emits a musky smell. Third right arm hectocotylised ; permanently attached ; developed free. Distribution, 2 species. Coasts of Norway, Britain, and the Mediterranean. CrrROTEUTHIS. Eschricht. 1836. Synonyms, Sciadephorus (Reinh 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 (C. MJulleri, Esch.) inhabits the coast of Greenland. PHILONEXIS, D’Orb. Etymology, philos, 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. Scmureus. Troschel. 1857. Body oval, without fins ; wider than the head; arms short; 166 MANUAL OF THE MOLLUSCA. suckers in two rows; the third left arm nectocotylised at the apex. Distribution, 2 species. Mediterranean. BowitHna. Strp. 1858. Similar to Eledone, but more gelatinous, and with oda suckers. 1 species living. SrEcTION B.—DECAPODA. en Arms 8. Tentacles 2, elongated, cylindrical, with expand ends. Suckers pedunculated, armed with a horny ring. Mouth — surrounded by a buccal membrane, sometimes lobed and fur-— nished with suckers. yes 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-_ mental 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. Fig. 39, Lingual teeth of Sepia officinalis (Cocken). sepiola, tricuspid in loligo, and denticulated in eledone. ‘Th lateral teeth or uncini are three on each side, and mostly simpl and claw-like. There were fifty rows of teeth in one specimer of sepia, the ribbon increasing in breadth from before to behind CEPHALOPODA. 167 The shell of the living decapods is either a horny ‘“ pen” (gladius) or a caleareous ‘‘ bone” (sepion) ; not attached to the animal by muscles, but so loose as to fall out when the cyst which contains it is opened. In the genus spirulaitisa delicate spiral tube divided into air-chambers by partitions (septa). In the fossil genus spirulirostra a similar shell forms the apex of a cuttle-bone; in the fossil conoteuthis a chambered shell is combined with a pen; and the belemnite 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. ) Famity IJ].—TrvuTHipm®. CALAMARIES, OR SQUIDS. Body elongated ; fins short, broad, and mostly terminal. Shell (gladius or pen) horny, consisting of three parts,—a shaft, and two lateral expansions or wings. Sub-family A. Myopside, D’Orbigny. yes covered by the skin. Lorieo. (Pliny) Lamarck. Calamary. Synonym, teuthis (Aristotle), Gray. Type, L. vulgaris (sepia loligo, L.). Fig. 1. Pl. L, fig. 6 (pen). 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. Sins terminal, united, rhombic. Mantle supported by a cervical ridge, and by two grooves in the base of the funnel. Swckers in two rows, with horny, dentated hoops. Tentacular club with four rows of suckers. Length (excluding tentacles) from 3 inches to 23 feet. Fourth left arm in male metamorphosed at its extremity. Steenstrup* says two species are confounded under the name of ZL. vulgaris. The variety occurring in the Atlantic, and not in the Mediterranean, is a distinct species (L. Forbesii, 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 papille, 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, 1857, 168 MANUAL OF THE MOLLUSCA. 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. Sub-genus. Teudopsis, Deslongchamps, 1835. Htymology, teuthis, a calamary, and opsis, like. Type, T. Bunelli, Desl. Pen like loligo, but dilated and spatulate behind. Fossil, 5 species. Upper Lias, Oolite; France and Wurtemberg. GonaATUS, Gray. Animal and pen like loligo in most respects. Arms with four series of cups; tentacular club with numerous small cups, and a single large sessile cup armed with a hook; funnel valveless. Distribution, a single species (G. amena, Miller sp.) is found on the coast of Greenland. SEPIOTEUTHIS, Blainyille. Synonyms, (?) Loliolus (Steenstrup); Chondrosepia (Leuckart). Type, 8. 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, Red Sea, Java, Australia, Mediterranean. BELOTEUTHIS, Minster. Etymology, belos, a dart, and teuthis. Type, B. subcostata, Minster. Pl. IL., 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 Minster, considered varieties of one only (differing in age and sex) by M. D’Orbigny, | GEOTEUTHIS, Miinster. Etymology, ge, the earth (7. e. fossil), and teuthis. Synonyms, belemnosepia (Agassiz), belopeltis (Voltz), loligo - sepia (Quenstedt), Coccoteuthis, Owen (part) Type, Loligo Aalensis (Schubler). CEPHALOPODA. 169 Pen broad, pointed behind; shaft broad, truncated in front; lateral wings shorter than the shaft. | Fossil, 9 species. Upper Lias, Wurtemberg; Calvados; Lyme Regis. Several undescribed species in the Oxford clay, Chippenham. Besides the pens of this calamary, the ink-bag, 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 Belemnitide. LEPTOTEUTHIS, Meyer. Etymology, Leptos, thin, and teuthis. Type, Li. gigas, Meyer, Oxford clay, Solenhofen. Pen very broad and rounded in front, pointed behind; with obscure diverging ribs. CRANCHIA, Leach, 1817. Named in honour of Mr. J. Cranch, naturalist to the Congo expedition. Synonym, Owenia, Prosch. Type, O. scabra, Leach. Body large, ventricose ; fins small, terminal; mantle supported in front by a branchial septum. Length two inches. Head very small. yes fixed. Buceal membrane large, 8-lobed. Arms short, suckers in two rows. Tentacular clubs finned behind, cups in four rows. Funnel valved. Pen long and narrow. Distribution, 3 species. West Africa; in the open sea. This genus makes the nearest approach to the octopods. SEPIOLA. (Rondelet) Leach, 1817. Example, §. 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. ins 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. §. Stenodactyla (sepioloidea, D’Orbigny) has no pen. I 170 MANUAL OF THE MOLLUSCA,. Distribution, 7 species. Coasts of Norway, Britain, Mediter- — ranean, Mauritius, Japan, Australia. Sub-genus. Rossia, Owen (R. palpebrosa). Synonym, Hetero- teuthis (Gray). Mantle, supported by a cervical ridge and groove. Suckers in two rows on the tentacles. First left arm hectocotylized throughout its length, and the corresponding right one in the middle. Length three to five inches. Distribution, 6 species. Regent Inlet, Britain, Mediterranean, Manilla, Sub-family B. Oigopside, D’Orbigny. Eyes naked. Fins always terminal, and united, forming a rhomb. Louicopsis, Lam. 1812. Etymology, loligo, and opsis, like. Synonyms, Leachia, Les., 1821; Perotis, Eschscholtz, 1827; Taonius, Steenstrup, 1861. Type, Li. pavo (Lesueur). Body elongated, mantle supported in front by a branchial septum. Arms short. Cups in two rows. Tentacles slender, often mutilated. Junnel valveless. Pen 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 feuthis. Type, C. yerani, Fer. Mantle supported in front by ridges. Funnelvalveless. 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 —_ of the tentacles three feet. f Distribution, 2 species. Atlantic, Mediterranean; on sae j weed in the open sea. AIsTIOTEUTHIS, D’Orbigny. Etymology, histion, a veil, and teuthis. Yype, H. bonelliana, Fér. Length 16 inches. Body 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. Medercetcce: in the open sea, ONYCHOTEUTHIS, Lichtenstein. Uncinated calamary. Etymology, onyx, a claw, and teuthis. Type, O. banksii, Leach (— bartlingu ?). Pl. I., fig. 7 and fig. 8 (pen). Synonyms, ancistroteuthis (Gray). Onychia (Lessa): Pen 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). O. banksii ranges from Norway to the Cape and Indian Ocean ; the rest are confined to warm seas. O. dusswmieri has been taken swimming in the open sea, 200 leagues north of the Mauritius. Distribution, 8 species. Atlantic, Indian Ocean, Pacific. ENOPLOTEUTHIS, D’Orbigny. Armed calamary. Etymology, enoplos, armed, and teuthis, Type, HE. smithii, Leach. Synonyms, ancistrochirus and abralia (Gray), octopodoteuthis (Ruppell), 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 larger size. In the museum of the College of Surgeons there is an arm of the specimen of EH. 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 calamary. 12 lve MANUAL OF THE MOLLUSCA. OMMASTREPHES, D’Orbigny. Sagittated calamary. Etymology, omma, the eyes, and strepho, to turn. Synonym, Hyaloteuthis (Gray). Type, O. sagittatus, Lam. Body cylindrical; terminal fins large and rhombic. Arms with two rows of suckers, and sometimes an internal mem- branous fringe. Tentacles short and strong, with four rows of cups. Pen consisting of a shaft 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 off Newfoundland, and are the 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, 7’. rhombus, T’. elegans. Mediterranean. Louiouvs, 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 Dosivicus, Stp. 1856. Somewhat like Ommastrephes. Lower portion of arms with large suckers, and the extremity with numerous small suckers. Tentacles with four or five hooks. Distribution, 1 species. Mediterranean. Famity [Y.—BELEMNITIDA. Shell consisting of a pen, terminating posteriorly in a cham- bered cone, sometimes inyested with a fibrous guard. The air- cells of the phragmocone are connected by a siphuncle, close to the ventral side. BELEMNITES, Lamarck. 1801. Etymology, belemnon, 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 concaye 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. Il., Fig. 5).¢ Guard fibrous, often elongated and cylindiical; becoming very thin in front, where it invests the phragmocone.{ Swckers provided with horny hooks. More than 100 species of belemnites have been found in a fossil state, ranging from the las to the chalk, and distributed over all Europe. A few species have been found in the chalk * The termination ites (from Jithos, a stone) was formerly given to all fossil genera. + Five specimens were 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 lias 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-bag. The phragmocone of a specimen corresponding to this in size measures 7} inches in length. ¢ The specific gravity of the guard is identical with that of the shell 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... os. ws. eee 2,674 Belemnitella mucronata, chalk se see ces oe | 2,677 Pinna, recent, from the Mediterranean ... ... ... 9,607 Trichites plottii, from the inferior oolite ... ... ... 2,670 Conus monile, recent ua aebetitechi sts oper LO Conus ponderosus, Miocene, enka Maes eee Prded) banal eer 174 MANUAL OF THE MOLLUSCA. 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 (siphwnele), 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 proportions, 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. Aca1i (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. clayatus. 3 species. Lias. Section II. Gasrrocati (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. Srction III. Norocar1 (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 a ae | ma CEPHALOPODA. 175 some of the 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. Pl. 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 enyeloped in a calcareous sheath. Fossil. 1 species. Lias. England. ACANTHOTEUTHIS (Wagner), Minster. Etymology, acantha, a spine, and teuthis. Synonyms, Kalzeno (Minster). Belemnoteuthis ? Type, A. prisca, Ruppell. Founded 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 belemnite 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 MOLLUSOA. Animal provided 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). Fossii in the Oxford clay of Chippenham. Similar horny claws have been found in the lias of Watchett, and a guard equally thin is figured in Buckland’s Bridge- water Treatise, t. 44, Fig. 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. CoNOTEUTHIS, D’Orb. Type, ©. Dupinianus, D’Orb. Pl. I1., Fig. 9. Neocomian, France ; Gault, 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. Fig. 40. Belemnoteuthis.* FAMILY V.—SEPIADA, Shell (cuttle-bone, or sepiostaire) calcareous; consisting of a broad laminated plate, terminating behind in a hollow, imper- * Fig. 40. Belemnoteuthis antiquus, }, 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 Kelloway rock, in the cabinet of J. G. Lowe, Esq.; ¢, is an ideal section of the same. Since this woodcut was executed a more complete specimen has been obtained for the British Museum ; the tentac/es are not longer than the ordinary arms, owing, perhaps, to their partial retraction; this specimen is figured in Dr, Mantell’s “« Petrifactions and their Teachings.” d, is a single hook, natural size. The specimens belonging to Mr. Cunnington and the late Mr. C. Pearce show the large acetabular bases of the hooks. CEPHALOPODA. 177 fectly chambered apex (mucro). Animal with elongated ten- tacles, expanded at their ends. Sepia (Pliny), Linnzeus. Type, 8. officinalis, L. Pl. 1., Fig. 5. Synonyms, Belosepia, Yoltz. (B. sepioidea, Pl. IL., Fig. 3, mucro only.) Palzeotenthis, Roem. Body oblong, with lateral fins as long as itself. Arms with four rows ofsuckers. Mantle supported by tubercles fitting into sockets on the neck and funnel. Length 3 to 28 inches. Shelli 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 and porous. S. Orbignyana, Pl. II., Fig. 2. The cuttle-bone was formerly employed as 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. Pl. Il., Fig. 3. 8. ungula occurs fossil in Texas. SPIRULIROSTRA, D’Orb. Type, S. Bellardu (D’Orb.). Pl. Il., Fig. 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. BELOPTERA (Blainyille), Deshayes. Etymology, belos, a dart, and pteron, a wing. Type, B. belemnitoides, Blainville. Pl. I1., Fig. 7. ; Shell, mucro (only known) chambered and siphuncled ; winged externally. Fossil, 4 species. Eocene. Paris; Bracklesham. BELEMNOSIS, Edwards. Type, B. anomalus, Sby. species. Eocene. Highgate (unique). 13 178 MANUAL OF THE MOLLUSCA. Shell, mucro chambered and siphuncled ; without lateral wings or elongated beak. HELIcERUS, Dana. Example, H. Fugiensis. Only species known. Shell like a belemnite, half-inch in diameter; guard thick, sub-cylindrical, fibrous; phragmocone slender, terminating in a fusiform spiral nucleus. In slate rock, Cape Horn. FAMILY VI.—SPIRULIDA. Shell entirely nacreous ; discoidal ; whorls separate, chambered (polythalamous), with a ventral siphuncle. SPIRULA, Lam., 1801. ‘Synonym, Lituus, Gray. Example, 8. levis (Gray). Pl. 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. Junnel 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. ORDER II.—TETRABRANCHIATA. Animal creeping ; protected by an external shell. Head retractile within the mantle. Hyespedunculated. Man- dibles calcareous. Arms very numerous. Body attached to the shell by adductor muscles, and by a continuous horny girdle. Branchie 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.* * The Chinese carve a variety of patterns in the outer opaque layer of the — $ shell, relieved by the pearly ground beneath. CEPHALOPODA. 179 It was long ago remarked by Dillwyn, that shells of the car- nivorous gasteropods were almost, or altogether, wanting in the palzeozoic 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. Itisstraightin . . . orthoceras . baculites. bent on itselfin . . ascoceras . ptychoceras._ curvedin ., a . cyrtoceras . toxoceras. ee spiral in ‘ ‘ . trochoceras . turrilites. discoidal in . ‘ . gyroceras . crioceras. discoidal and producedin lituites . ancyloceras. involute in . ; nautilus . ammonites. Internally, the shell is divided into cells or chambers, by a series of partitions (septa), connected by a tube or siphuncle. 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 in goniatites (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 the section of a shell, without concealing any part of it. The woodcut, Fig. 50, is taken from a more perfect specimen, subsequently acquired by the British Museum, in which the relation of the animal to its shell is accurately shown. + A. heterophyllus, Sby., from the lias, Lyme Regis. British Museum. Only one side is represented ; the arrow indicates the dorsal saddle. 180 MANUAL OF THE MOLLUSCA. The outlines of the septa are termed sutures ;* when they are — folded the elevations are called saddles, and the intervening de- ~ pressions lobes. 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 siphuncle 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, gyroceras, 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 lamelle of a coral. The position of the siphuncle is very variable; in the ammonitide it is external, or close to the outer margin of the shell (Fig. 44). In the nautilide it is usually central (Fig. 42), or internal (Fig. 48). Fig. 42. Nautilus. Fig. 43. Clymenia. Fig. 44. Hamites.f The air-chambers 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.t The body-chamber 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 communis _ 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. + Fig. 42. Nautilus Pompilius,L. Fig. 43. Clymenia striata, Miinst., see Pl. II+y Fig. 16. Fig. 44. Hamites cylindraceus, Defr., see Fig. 65. t Most 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, _ CEPHALOPODA. 181 and affords no clue to the many curious modifications observable in the fossil forms. In the ammonites we frequently find a dorsal Fig. 45. Ammonites, f Fig. 46. Goniatites.* process, or lateral projections, developed periodically, or only in the adult (Fig. 62, and Pl. III., Fig. 5). In phragmoceras and gomphoceras (Figs. 47, 48) the aperture is so much contracted that it is obvious the animal could not have withdrawn its head into the shell like the nautilus. 1 Fig. 47. Gomphoceras Fig, 48. Phragmoceras.f 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 (ss), which is almost isolated, may have * Fig. 45. Section of Ammonites obtusus, Sby. lias, Lyme Regis ; from a very young specimen. Fig. 46. Section of goniatites sphericus, Sby. carb. limestone, Bolland (in the cabinet of Mr. Tennant). The dotted lines indicate the lateral extent of the - body-chamber. — _ + 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 MANUAL OF THE MOLLUSCA. served for the passage of the funnel, whilst the upper and larger space (cc) 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, 2), formed by the union of the two dorsal arms, which correspond to the shell-secreting arms of the argonaut. In the extinct ammonites we have evidence that the aperture was guarded still more effectively 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 trigonellites, and pointed out the re- semblance of their internal structure to the cancellated tissue of bones. Their external 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 arefound, and a singlespecimen has been figured by M. D’Archiac, from the Devonian rocks of the Eifel, where it was associated with goniatites.t Calcareous mandibles, or rhyncholites (F. Biguet), have been obtained from all the strata in which nawtili 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 — Fig. 49.+ - * This form was discovered by the late Miss Mary Anning, the indefatigable collector of the lias fossils of Lyme Regis, and described by Mr. Strickland, Geol. Journal, vol.i., p. 232. Also by M. Voltz, Mem, de l'Institut, 1837, p. 48. ; + Trigonellites lamellosus, Park. Oxford clay, Solenhofen (and Chippenham), associated with ammonites lingulatus, Quenstedt. (= A, Brightii, Pratt), From a specimen in the cabinet of Charles Stokes, Esq. t The trivonellites have been described by Meyer as bivalve shells, under the generic © name of aptychus ; by Deslongchamps under the 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 7. sanguinolarius. found with am. depressus, in the lias of Boll. Ruppell, Voltz, Quenstedt, and Ziéten, regard the trigonellites as the opercula of ammonites, an opinion also entertained by many of the most experienced fossil collectors in England. Some of them have been described by Rolle (1862) as Cyclidia and Scaphanidia, § M. D’Orbigny has manufactured two genera of calamaries out of these natidltas beaks (rhynchoteuthis and paleoteuthis). In the innumerable sections of ammonites which have been made, no traces of the mandibles have ever been discovered, CEPHALOPODA. 183 nautilus (N. arietis, Reinecke, =N. bidorsatus, Schlotheim), is found, and two kinds of rhyncholite; one sort, corresponding with the upper mandible of the recent nautilus, has been called ‘‘rhyncholites hirundo” (Pl. Il., Fig. 11); the other, which appears to be only the lower shisadstTe of the same species, has been described under the name of ‘‘ conchorhynchus ayirostris.”’* They also occur in the belemnite beds of the middle has 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 tetrabranchiata, it is necessary to take into consideration the varying circumstances under which they have been preserved. In some straga (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 haye lost their shells; but perfect casts of the chambers, formed of calcareous spar, remain. Fossil orthocerata and ammonites are evidently in many instances dead shells, being overgrown with corals, serpulz, 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.t In this state they are permeated by mineral water, which slowly deposits calearecus 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, leaying 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 (Schlotheim), described by Blainville as the beak of a brachiopod! + Called spondylolites by old writers. ¢ 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 MANUAL OF THE MOLLUSCA. calculated, by their forms, for swimming; and the straight= shelled orthocerata and baculites 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 partitions 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.t 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 orthocerata, whose long straight shells were particularly exposed to danger; in these the_preservation of the shell was proyided 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 sheli is rather large in the nautili, and causes an opening to remain through the shell, until the wmbilicus 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, isalone © sufficient to convince us that the chambered cephalopods could — * A nautilus pompilius (in the cabinet of Mr. Morris) weighs llb.,and when the siphuncle is secured, it floats with a 2lb. weight in its aperture. The animal would have displaced two pints (= 23lbs.) of water, and therefore, if it weighed 3lbs., the specific gravity of the animal and shell would scarcely exceed that of salt water. + The siphuncle and lobed septa did not hold the animal in its shell, as Von Buch imagined: that was secured by the shell-muscles. The complicated sutures perhaps indicate lobed ovariés; 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 tetrabranchiata. 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 (3), the second of females (9). Dr. Melville has made a sunilar suggestion with respect to the nautili; namely, that the umbilicated specimens are the males, the imperforated shells, females. Professor Van der Hoeven has described the difference in the shells of the two sexes; + 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 : butit contains 107 plates, with figures of 200 species of cephalopods, belonging to the genera Goniatites, Nothoceras, Trochoceras, Hercoceras, Litwites, Phragmoceras, Gom- phoceras, and Ascoceras. Famity I.—NAUTILIDE. Shell. Body-chamber capacious. Aperture simple. Sutures simple. Stphuncle central or internal. (Figs. 50, 91.) NAUTILUS, Breynius, 1732. 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. IZ, Fig. 10. The umbilicus is small or obsolete in the typical nautili, and the whorls enlarge rapidly. In the paleozoic 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 265lbs. 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 liquid 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 History, vol. xix. 1857. 186 MANUAL OF THE MOLLUSCA. — 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 labial © tentacles, twelve or thirteen in each group ; they appear to answer f Fig. 50. Nautilus pompilius in its shell.* to the buccal membrane 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 fentacles are lamellated on their inner surface, and are retractile within sheaths, or ‘‘digita-— tions,” which correspond to the eight ordinary arms of 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 by the hood (h); t, tentacles, nearly concealed in their sheaths; 7, funnel; m, margin of the mantle, very much contracted; n, nidamental gland; a, c, air-cells and siphuncle ; 8, portion of the shell; a, shell-muscle. The internal organs are indicated by dotted lines; 8, branchie ; A, heart and renal glands; c, crop; g, gizzard; /, liver; 0, ovary. — CEPHALOPODA. 187 cuttle-fishes; 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 aplysia. (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 hood 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 (peri- cardium), and is most probably filled with fluid from that cavity (Owen). Respecting 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 ainount of muscular exertion. Professor Owen gives the following passage, from the old Dutch naturalist, Rumphius, 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 by Lovén, a conclusion with which we cannot agree. The cephalopods ought to be compared with the /arval 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 raft (‘anthina). However, on examining the nautilus preserved in the British Museum, and finding that the funnel was only part of a muscular collar, which extends ail round the neck of the animal, we could not avoid noticing its resemblance to the siphonal lappets of paludina, and to that series of lappets (including the operculigerous lobe) which surrounds the trochus (Fig. 114). 188 MANUAL OF THE MOLLUSCA. but at the 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, being driven up by 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. 8. 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 Lovén, who appears to have taken the details from M. Valenciennes’ Memoir in the Archives du Musewm, vol. ii., p. 257. Ah, hood; s, siphon. It is just possible that when the © nautilus issues from its shell, the gas contained in the last, incomplete, air-chamber may expand; but this could not happen under any great pressure of water. CEPHALOPODA. 189, has taken advantage of these characters for dividing the nautili into three groups, viz., 1. Levigati. 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 strisn. 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. Pl. Il., Fig. 12, London Clay, Highgate. Shell, sutures with a deep lateral lobe; siphuncle nearly internal, large, continuous, resembling a succession of funnels. Fossil, 4 species. Eocune; North America, Europe, India. Sub-genus 2 Discites, McCoy. Whorls all exposed; the last chamber sometimes produced. Fossil, 5 species. Lower Silurian.—Carb. limestone. Temnocheilus, McCoy. Founded on the carinated species of the carb. limestone, of which 5 are known. Cryptoceras, D’Orb. Ascoceras, Barr. Founded on N. dor- salis, Phil., and one other species, in which the siphuncle is nearly external. Fossil, 16 species. Upper Silurian—Carb. LitvITEs, Breynius. Etymology, lituus, a trumpet. Synonyms, Hortolus, Montf. (whorls separate). Trocholites, Conrad. Example, L. conyolvans, Schl. J. 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. TROCHGOCERAS, Barrande, 1848. Example, T. trochoides, Bar. Shell nautiloid, spiral, depressed. Fossil, 44 species. Upper Silurian ; Bohemia. Some of the species are nearly flat, and, having the last chamber produced, would formerly haye been congiieee Lituites. MANUAL OF THE MOLLUSCA. eee ae Fig. 52. Clymenia striata, Munst.* Fig. 53. C. linearis, Munst. CLYMENIA, Munster, 1832. Etymology, Clymene, a sea-nymph. Synonyms, Endosiphonites, Ansted. Sub-clymenia, D’Orb. Example, C. striata, Pl. II., Fig. 16 (Mus. Tennant). Shell discoidal; septa simple or slightly lobed; siphuncle internal. Fossil, 45 species. Upper Silurian—Mount. Limestone. North America, Europe. FAmILy IJ.—ORTHOCERATIDZA. Shell straight, curved, or discoidal; body chamber small; aperture contracted, sometimes extremely narrow (Figs. 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 cephalicopening. 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 tetrabranchiate ; and the cheyron- shaped coloured bands preserved on the orthoceras anguliferus,t sufficiently prove that the shell was essentially external. ’ ORTHOCERAS, Breyn. Etymology, orthos, straight, and ceras, a horn. Synonyms, Oycloceras, McCoy. Gonioceras, Hall.t Conoceras, Brvnn. | Example, O. Ludense (diagram of a longitudinal section) — PL.I1., 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 Clymenia from’ Phillips’ Pal. Fos., Devon- shire. + Figured by D’Archiac and Verneuil, Geol. Trans. + Theca and Tentaculites are provisionally placed with the aeaigeae they pro- ad belong here, CEPHALOPODA. 191 The orthocerata are the 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. Sub-genus. 1. Cameroceras, Conrad (= melia and thoracoceras, Fischer ?), Siphuncle lateral, sometimes very large (simple ?). Casts of these large siphuncles were called hyolites by Eichwald. 27 species. Lower Silurian—Trias? North America and - Kurope. Fig. 54. Actinoceras.* Fig. 55. Ormoceras. 2. Actinoceras (Bronn), Stokes. Siphuncle very large, in- flated between the chambers, and connected with a slender ‘central tube by radiating plates. 6species. 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—Deyon; 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. COrmoceras Bayfieldi, Stokes. Drummond Island. (From Mr. Stokes’ paper, Geol. Trans.) 192 MANUAL OF THE MOLLUSCA. stationed on Drummond Island. Specimens haye also been brought home by the officers of many of the Arctic expeditions. i But with the exception of one formerly in the possession of CZ al Fig. 56. Huronia vertebralis.* Lieutenant Gibson, and another in the cabinet of Mr. Stokes; the siphuncle only is preserved, und 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 funnel-shaped diaphragms. 12 species. Lower Silurian, New York. Shell perforated by two distinct siphuncles? O. bisipho- natum Sby, Caradoc sandstone, Brit. | ‘‘Orthocerata with two siphuncles haye 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 gemelliparum and proteiforme 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 4 only indicated in the specimen by “ colourless lines on the brown limestone.” 6 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 4. t Shells of Bellerophon and Murchisonia are found under the same circumstances. ; CEPHALOPODA. 193 have resembled Gonioceras, and the external tube to be a simple cavity, formed by the approximation of the lateral angles. Discosorus (conoideus) Hall, 1852. Pal. New York. This fossil appears to be a siphuncle similar to those figured by Dr. Bigsby in 1824 (Geol. Trs. I., Pl. 30, f. 6), and which have been correctly referred to the orthocerata by Quenstedt. GoMPHOCERAS, J. Sby. 1839. Etymology, gomphos, a club; and ceras, a horn. Synonyms, Apioceras (Fischer). Poterioceras (McCoy). Tyve, G. pyriforme, Sby., Fig. 58, and G. Bohemicum, Bar. Fig, 47. Fig. 57. Endoceras.* Fig. 58. Gomphoceras.t{ Shell, fusiform or globular, with a tapering apex; aperture contracted in the middle; siphuncle moniliform, sub-central. Distribution, 27 species. Lower Silurian—Carb. North America, Europe, Brit. Barrande figures 70 species in Vol. II. pf his ‘‘ Systéme Silurien,” 1865, nearly all of which are believed to be new. . ONCcOCERAS, Hall, Etymology, oncos, a protuberance. Type, O. constrictum, Hall. Trenton limestone. '* Fig. 57. Diagram of an endoceras (after Hall). a, shell-wall; 5, wall of siphuncle’ tcc, diaphragms (‘‘embryo-tubes ” of Hall). + Fig. 58. Gomphoceras pyriforme. L. Ludlow rock, Mocktree Hill, Herefordshire, {From Murchison’s Silurian Syst. reduced 3.) s, beaded siphuncle. K 194 MANUAL OF THE MOLLUSCA. Shell, like a curved gomphoceras ; siphuncle external. Distribution, 3 species. Silurian, New York. PHRAGMOCERAS, Broderip. Etymology, phragmos, a partition, and ceras, a horn. Type, P. veutricosum (Steininger species), Pl. II., Fig. 15. Shell curved, laterally compressed; aperture contracted in the middle; siphwnele, ventral, radiated. Example, P. callistoma, Bar., Fig. 48. Distribution, 15 species. Lower Silurian—Carb.; Brit., Germany. CyrTOcERAS, Goldf., 1832. Etymology, curtos, curved, ceras, horn. Synonyms, Campulites, Desh., 1832 (including gyroceras). Aploceras, D’Orbigny. Campyloceras and trigonoceras, McOoy. Gyroceras, D’Orbigny. Example, C. hybridum, Volborthi, and Beaumonti (Barrande). Shell curved ; siphuncle small, internal, or sub-central. Fossil, 84 species. Lower Silurian—Carb.; North and South America and Europe. " \\ < Till) sr et" | tae ou 111) Salil ] MU) iy 7; \ Fig. 59.* GYROCERAS, Meyer, 1829. Etymology, gyros, a circle, and ceras. Synonym, Nautiloceras, D’Orbigny. | Example, G. eifeliense, D’Arch. (Pl. II., Fig. 18). Devonian; © Eifel. | * Fig. 59. Gyroceras Goldfussii. (= ornatitm Goldf.). 5, siphuncle of G. depressum, : Goldf. sp. Devonian. Eifel. From MM. D’Archiac and Verneuil. CEPHALOPODA. 195 Shell nautiloid ; whorls separate ; siphuncle excentric, radiated. Fossil, 17 species. Upper Silurian—Trias? North America and Europe. THORACOCERAS, Fischer, 1844. Synonym, Melia, Fischer (not L.). Type, T. vestitum. Shell straight, elongated, conical, with a small lateral straight siphuncle. Fossil, 20 species. Lower Silurian—Carb. United States and Europe. NotTHOcERAS, Barrande, 1856. Shell nautiloid, slightly involute ; septa slightly arched, with- out lobes. Fossil, 1 species. Upper Silurian. Famity III.—AMMONITIDA. Shell. Body-chamber elongated ; aperture guarded by processes, and closed by an operculum; sutures angulated, or lobed and foliated ; stphuncle external (dorsal, as regards the shell). The shell of the ammonitide has essentially the same structure as that of the nautilus. Itconsistsof 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,+ 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 therefore 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 cristaté 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 (Pl. III., Fig. 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 Forbes detected a punctate structure in one species. + A. serpentinus, Schloth, U. Lias, Wellingboro. Rev, A. W. Griesbach. K 2 196 MANUAL OF THE MOLLUSCA. an arch 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 branchiz on one side. In the British Museum there are deformed specimens of A. obtusus, amaltheus, and tuberculatus. Fig. 60.t GONIATITES, De Haan. Hiymology, gonia angles, (should be written gonialites ?). Synonym, aganides, D’Orbigny (not Montf= Aturia zic-zac). Examples, G. Henslowi (Pl. IlI., Fig. 1), G. sphericus (Figs. 60 and 46). Shell discoidal ; sutures lobed ; siphuncle dorsal. Distribution, 197 species. Upper Silurian—Trias. Europe. RHABDOCERAS, Hauer, 1860. Shell straight, orthoceratoid, with bold sculpture. Septa with rounded lobes. Distribution, 1 species. Trias. Germany. * This unique and abnormal specimen is in the cabinet of S. P. Pratt, Esq. + Fig. 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, 8 species. Devonian, Germany. wd oY V4 We Fig. 61.* CERATITES, De Haan. Type, C. nodosus (PI. III., Fig. 2). Shell discoidal ; sutures lobed, the lobes crenulated (Fig. 61). Distribution, 29 species. Devyonian—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. 62.+ AMMONITES, Bruguiere. Etymology, ammon, a name of Jupiter, worshipped in Libya under the form ofaram. The ammonite isthe 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). The arrow in the dorsal lobe points towards the aperture. 1 Fig. 62. Ammonites rostratus (Sby.) From the U. greensand of Devizes, in the cabinet of W. Cunnington, Esq. 6, front view of one of its partitions. 198 MANUAL OF THE MOLLUSCA. Distribution, about 700 species. Trias—Chalk. Coast of Chili (D’Orbigny), Santa Fé 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 difforences of age, &c. Thus, according to Mr. Seeley, the Am- monites 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 with an entire keel. 1. Arietes, L. oolites, A. bifrons (Pl. ITI., Fig. 6), bisul- catus (Pl. ITI., Fig. 7). 2. Falciferi, L. oolites, A. serpentinus, radians, hecticus. 3. Cristati, cretaceous, A. cristatus, rostratus (Fig. 62), varians. B. Back crenated. . . Amalthei, ool. A.amaltheus, cordatus, excavatus. . Rothomagenses, cret. A. rothomagensis, from Rothoma- gum, Rouen (Pl. III., Fig. 4). C. Back sharp. 6. Disci, oolitic, A. discus, clypeiformis. D. Back channelled. cret. A. dentatus, lautus. ool. A. Parkinsoni, anguliferus. oe 7. Dentati, E. Back squared. 8. Armati, L. ool. A. armatus, athletus, perarmatus. 9. Capricorni, LL. ool. A. capricornus, planicostatus. 10. Ornati, gol. A. Duncani, spinosus (Pl. III., | Fig. 5). CEPHALOPODA. 199 F. Back round, convex. 11. Heterophylli, LL. ool. A. heterophyllus (Fig. 41). 12. Ligati, cret. A. planulatus (Pl. IT., Fig. 3). Fig. 63. Ammonites coronatus.* 13. Annulati, ool. A. annulatus, biplex, giganteus. 14. Coronati, ool. A. coronatus (Fig. 63), subleevis. 15. Fimbriati, ool. A. fimbriatus, lineatus, hircinus. 16. Cassiani, 36 species of very variable form, and remarkable for the number and complexity of their lobes. Trias, Austrian Alps. < Fig. 64.4 Examples, A. Maximiliani (Fig. 64), A. Metternichii. A CRIOCERAS, Leveille. Etymology, krios, a ram, and ceras, a horn. Synonym, Tropzeum, Sby. Example, C. cristatum, D’Orbigny (Pl. III., Fig. 8). Shell discoidal; whorls separate. Distribution, 13 species. Neocomian——- Upper greensand. Britain, France. * Fig. 63. Profile of Ammonites ‘coronatus (Brug.). (Reduced 3 from D’Orbigny.) Kelloway Rock, France. d/, dorsal lobe; s s, dorsal saddles; ?' /' lateral lobes; s' s', lateral saddles ; accessory and ventral lobes. The number of accessory lobes increases with age. + Fig. 64. Am. Marimiliani, Klipstein. (= A. bicarinatus, Miinst.) Trias, Hailstadt (copied from Quenstedt). A, profile, showing the numerous lobes and saddles; B, suture of one side; v, dorsal saddle. 200 MANUAL OF THE MOLLUSCA. ToxocEeras, D’Orbigny. Etymology, toxon, a bow, ceras, a horn. Example, T. annulare, D’Orbigny (Pl. III., Fig. 12). Shell bow-shaped ; like an ammonite uncoiled. Distribution, 20 species. Neocomian, Between this and crio- ceras and ancyloceras there are numerous intermediate forms. ANCYLOCERAS, D’Orbigny. Etymology, anculos, incurved. Synonym, Anisoceras, Pictet. Example, A. spinigerum (PI. ITI., 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 (Chili and Bogota), Europe. ScAPHITES, Parkinson. Etymology, scaphe, a boat. Example, 8. equalis (Pl. IIL, Fig. 9). Shell at first discoidal, with close whorls; last chamber detached and recurved. Distribution, 19 species. Oolite—Chalk. Europe, India. HELICOcERAS, D’Orbigny. Etymology, helix (helicos), a spiral, and ceras, a horn. Example, H. rotundum, Sby. species (Pl. III, Fig. 11— diagram). Shell spiral, sinistral; whorls separate. Distribution, 11 species. Inferior oolite?—Chalk. Europe, India. TURRILITES, 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 makesa genus (heteroceras) of two turrilites, in which the last chamber is somewhat produced and recurved. T. reflexus soe T. 20, Fig. 16) has its apex inflected and concealed. CEPHALOPODA. 201 HAmMITES, Parkinson. Etymology, hamus, a hook. Example, H. attenuatus (Pl. ITI., Fig. 15). Shell hook-shaped, or bent upon itself more than once, the courses separate. Distribution, 58 species. Neocomian—Chalk. South America (Tierra del Fuego), Europe, India. b F mm a Fig. 65, Sutures of Hamites cylindraceus, Defr.* The inner courses of this shell probably break away, or are ** decollated,” in the progress of its growth. (Forbes.) M. D’Orbigny has proposed a new genus, hamulina, for the twenty neocomian species. PrycHocERAs, D’Orbigny. Etymology, ptyche, a fold. Example, P. emericianum, D’Orbigny (Pl. III., Fig. 14). Shell bent once upon itself; the two straight portions in contact. Distribution, 8 species. Neocomian—Chalk. Britain, France, India. BAcuLITES, Lamarck. Etymology, baculus, a staff. Example, B. anceps (Pl. III., Fig. 13). Shell straight, elongated; aperture guarded by a dorsal process. Distribution, 17 species. Neocomian—Chalk. Europe, South America (Chili), India. Baculina, D’Orbigny, 2 species. B. Rouyana. Neocomian. France. Sutures not foliated. The chalk of Normandy has received the name of baculite 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 Museum. a, dorsul line; 6, ventral. Baculite limestone, Fresville. K 3 202 MANUAL OF THE MOLLUSCA. CHAPTER II. CLASS II.—GASTEROPODA. The gasteropods, including land-snails, sea-snails, whelks, limpets, and the like, are the types of the mollusca ; 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 nucleobranchs are ‘‘ aberrant” gasteropods, haying the foot thin and vertical; they swim near the surface of the sea in a reversed position, or adhere to floating sea-weed. _ The gasteropods are nearly all unsymmetrical, the body being coiled up spirally, and the respiratery organs of the left side being usually atrophied. In chiton and dentalium the branchie and reproductive organs are repeated on each side. - A few species of cymba, littorina; paludina, 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,+ The gasteropods form two natural groups; one breathing air * Fig. 66. Carinarva cymbium, Desh. = C, cristata, L. sp. (after Blainville), Medi- terranean. p, proboscis; ¢, tentacles ; 6, branchie; s, shell; 7, foot; d, disk. + M. Lovén believes that the embryo shell of the nudibranchs falls off at the time they acquire a locomotive foot. GASTEROPODA. 903 (pulmonifera), the other water (branchifera). The water-breathers have at first a small nautiloid shell, capable of concealing them entirely, andclosed by an operculum. Instead of creeping, they swim with a pair of ciliated fins springing from the sides of the ) 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 calyptrea 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 difference between the young of Fig. 67.* eolis and aplysia, or buccinwm and vermetus. (M. Edwards.) The development of the branchiferous gasteropods may be observed with much facility in the common river-snails (palu- 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. 68. Paludina vivipara.}{ 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). 0, the operculum; the original is not larger than the letter o. + 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 alimentary canal. Surrey Docks, June, 1850. 204 MANUAL OF THE MOLLUSCA. The development of the air-breathers goes on within the shell, and has been traced by Van Beneden, Gegenbaur, and others in Limax, Veronicella, Vitrina, Bulimus, and Helix. The shell of the gasteropods is usually spiral, and univalye; more rarely tubular, or conical, and in one genus it is multivalve. The following are its principal modifications :— A. Regularly spiral, a. elongated or turreted; terebra, turritella. b. cylindrical; megaspira, pupa. c. short; buccinwm. d. globular ; natica, helix. e. depressed ; solarium. f. discoidal ; planorbis. . conyolute; aperture as long as the shell; cyprea, bulla. . fusiform; tapering to each end, like fusus. trochiform ; conical, with a flat base, like trochus. . turbinated ; conical, with a round base, like turbo. . few-whorled ; Helix hemastoma. Pl. XIL, Fig. 1. m. imany-whorled ; Helix polygyrata. Pl. XII,, Fig. 2. nm. ear-shaped ; haliotis. B. Irregularly spiral; siliquaria, vermetus. C. Tubular; dentaliwm. D. Shield-shaped ; wmbrella, parmophorus, E. Boat-shaped ; navicella. F.. Conical or limpet-shaped ; patella. G. Multivalve and imbricated ; chiton. The only symmetrical shells are those of carinaria, atlanta, dentaliwm, 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 cayity 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), and Huomphalus 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, cyclostoma, and valvata ; SPs SS * The curve of the spiral shells and their opercula 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 Rev. H. Moseley, “On geometrical Forms of Turbinated and Discoid Shells.”—Piil, Trans, Lond. 1838. Pt. 2, p. 351. | ‘sd GASTEROPODA. 205 but more commonly the inner side of the spiral tube is formed by the pre-existing whorls (Fig. 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 wmbilicated (e.g. solarium). The perforation may be a mere chink, or fissure (rima), as in lacuna; or 1t may be filled up by ashelly 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. ae posterior canal. aperture. BP? eich et Vind b 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 pyramidellide, oblique and spiral in the nucleobranchs and emarginule, and mammillated in Turbinella pyrum and Fusus antiquus. The apex is directed backwards in all except some of the patellide, in which it is turned forwards, over 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, 906 MANUAL OF THE MOLLUSCA. In the adult condition of some shells the 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 body-whorl, 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 (holos- tomata), but notched or produced into a canal, in the carnivorous families (sighonostomata) ; this canal, or siphon, 3 is respiratory in its office, 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. strombide and ovulum volva); it is represented by the slit in scissurella, the tube of typhis, the perforation in /issurella, 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 (carocolla) ; 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 (/abrum), the left side by the inner or columellar lip (labiwm), 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 bulimulus) ; but more frequently it is thickened ; or reflected; or curled inwards (inflected), as in cyprea ; 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 tothe — 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 limaw and parmophorus ; and those which are covered by the GASTEROPODA. 207 mantle-lobes when the animal expands, acquire a glazed or enamelled surface, like the cowries; when the shell is deeply immersed in the foot of the animal it becomes partly glazed, as in cymba. 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 unlike the muscular scar in the shell. It is developed in the embryo, within the egg, 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. doliwm, cassidaria, harpa, navicella), it is quite rudimentary or obsolete. Fig. 70. Fig. 72. Fg. 73. The operculum is described as— Concentric, when it increases equally all round, and the nucleus is central or sub-central, as in paludina and ampullaria (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 paludomus. 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 strombus (Fig. 76). Spiral, when it grows only on one edge, and revolves as it grows ; it is always sinistral in dextral shells. Paucispiral, or few-whorled (Fig. 73), as in littorina. 208 MANUAL OF THE MOLLUSCA. Sub-spiral, or scarcely spiral, in melania (Pl. VIIL., Fig. 25*). Multispiral, or many-whorled (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, asin 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 ampullaria and natica ; in paludina it is concentric, in paludomus lamellar, in valvata spiral ; in solariwm and cerithium, it is multispiral or paucispiral. The researches of Dr. Lovén* 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.t 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 lable 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 most subject. to these adaptive modifications, and can never form the basis of a philosophical system. { * Ofversiot af Konol. Vetensk. Akad. Forhandl. 1847. + 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. Tenioglossa, teeth 3. 1.3; Littorina, Natica, Triton. 6. Toxoglossa, teeth 1. 0. 1; Conus, Terebra? c. Hamiglossa, teeth 1. 1. 1; Murex, Buccinum. d. Rachiglossa, teeth 0. 1.0; Voluta, Mitra? e. Gymnoglossa, teeth 0; Pyramidella, Cancellaria, Solarium? f. Rhipidoglossa, teeth 00, 1.00; Nerita, Trochus. } The carnivorous opossums have teeth adapted for eating flesh, but are not on that account to be classified with the placental carnivora. 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. GASTEROPODA. 209 Some of the gasteropoda can suspend themselves by glutinous threads, like litiopa 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 (cyclostoma suspensum) * also suspends itself. (Guilding.) The origin “€ these threads has not been explained ; but some of the limaces 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 Fig. 75. bs the first that possessed much merit, and several of his orders — haye since been united with advantage. System of Cuvier. System now adopted. Class. GASTEROPODA. Order 1. Pectinibranchiata 2. Scutibranchiata : , Cyclobranchiata Ord. Prosobranchiata, M. Edw. . Tubulibranchiata . Pulmonata Ord. Pulmonifera. 3 4 9) 6. Tectibranchiata 7 8 H . Nudibranchiata. ETEROPODA. Ord. Nucleobranchiata, Bl. . Inferobranchiata f Ord. Opisthobranchiata, M. Edw. Class, ORDER I. PROSOBRANCHIATA. 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 branchie are almost always lodged. Branchie pectinated, or plume-like, situated (proson) in advance of the heart. Sewes 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 MOLLUSCA. 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 branchiai chamber ; gills one or two, comb-like, placed obliquely over the balay Species all marine. Famity I.—StTromBip&. Wing-shells. Shell with an expanded lip, deeply notched near the canal. Operculum claw-shaped, serrated on the outer edge. Animal furnished 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. ao SR ——Z PE RWWA Fig. 76.¥ Stromsgvs, L. Stromb. Litymology, strombos, a top. Type, 8. pugilis (Pl. IV., 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 * Fig. 76. Strombus auris- Diana, L. (after Quoy and Gaimard), Amboyna. P,P boscis, between the eye-pedicels ; f, foot, folded up; 0, operculum; m, border of mantle; s, respiratory siphon. GASTEROPODA. 211 the anterior canal. Lingual teeth (S. floridus) 7 cusped ; uncini, 1 tri-dentate, 2, 3 claw-shaped, simple (Fig. 77).* pri Fig. 77. Strombus. (Wilton). Strombus (floridus) is described by Lovén as haying a non- retractile, produced muzzle, like Aporrhais. 8. gibberulus is represented by Dr. Bergh with all the uncini denticulated. Distribution, 65 species. West Indies, Mediterranean, Red 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. fisswrellus, L., some of which have been placed with rostel- 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. zample, 8. Bartonensis. Pl. 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.) PTEROCERAS, Lam. Scorpion shell. Etymology, pteron, a wing, and ceras, a horn. Type, P. lambis. Pl. IV., 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 aporrhazs, and is unlike that of the whelks; but it is more probable that aporrhais 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 (cerithiade). . RosTELLARIA, Lam. Etymology, rostellum, a little beak. Synonym, Fusus, Humphreys. Example, R. curta. Pl. 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. Red Sea, India, Borneo, China. Range, 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., Rost. ampla, Solander. London clay). Sub-genus 2 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 fringes, as in ranella. Fossil, 5 species. Inf. oolite—chalk. Britain, France. SERAPHS, Montfort. (Terebellum, Lam.) Etymology, diminutive of terebra, 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 terebellwm has an operculum like strombus ; ite eye-pedicels are simple, without tentacles. (Adams.) In one fossil species, 7’. fusiforme, there is a short posterior canal, as in rostellaria. Famity IIl.—MuvRIcipz. 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 known to have no affinity with the Atlantida, but to be the larva form of species belonging to the Muricide. MS uaa) PN Siena | Fig. #8. Murer tenuispina. (Wilton.) Murex (Pliny), L. Types, M. palma-rose, Pl. IV., Fig. 10. M. tenuispina, Pl. iV., Fig. 9. M. haustellum, Pl. IV., Fig. 8. M. radix, oinnatus. Shell ornamented with three or more continuous longitudinal varices ; aperture rounded; beak often very long; canal partly slosed ; operculum concentric, nucleus sup-apical (Pl. IV., Fig. 10); lingual dentition (M. erinaceus), teeth single, three crested ; uncini single, curved. For dentition of WM. tenwispina see Fig. 78. 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, &e. 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. IM. 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 mwrex ; the small shells were 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. brandaris for the same purpose. (M. Boblaye.) | Typuis, Montfort. Etymology, typhos, smoke. 214 MANUAL OF THE MOLLUSCA. Type, T. pungens. Pl. IV., Fig. 11. 4 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, Oape, India, Western America. ~—d0 fathoms. Fossil, 8 species. Eocene—. London, Paris. PISANIA, Biyon, 1832. Etymology, a native of (the coast near) Pisa, in Tuscany. Synonyms, Pollia, Enzina, and Euthria (Gray). Types, P. maculosa. Pl. IV., Fig. 14 (Enzina), zonata, Pl. Va, Big... Shell with numerous indistinct varices, or smooth and spirally striated ; canal short; inner lip wrinkled ; outer lip crenulated. Operculum ovate, acute; nucleus apical. The pisanie have been usually confounded with buccinum, murex, and ricinula. Distribution, about 120 species. West Indies, Africa, India, Philippines, South Seas, Western America. Fossil, Pspecies. Hocene—Britain, France, &c. j RANELLA, Lam. Frog-shell. Synonym, Apollon (Montfort and Gray). Types, R. granifera. Pl. IV., Fig. 12. RB. 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. ange, low-water to 20 fathoms. Fossil, 23 species. Eocene—. TriITon, Lam. Etymology, Triton, a sea-deity. Synonym, Persona (Montfort, Gray). ' Type, T. tritonis, L. species. Pl. IV., Fig. 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, Ranging from GASTEROPODA. 215 low water to 10 or 20 fathoms; one minute species has been dredged at 50 fathoms. Fig. 79. One of the buccal pla es of Triton, +® (Wilton.) Fossil, 45 species. Eocene—. Britain, France, &c. Chili. The great triton (7. tritonis) is the conch b'own by the Australian and Polynesian Islandeis. A very similar species (7. nodiferus) is found in the Medi.erranean, and a tard in the Fig. 80. Teeth of Tritor, 24°. (Wilton.) - West Indies. The buccal plates and teeth of Triton are shown in Figs. 79, 80. FASCIOLARIA, Lam. Etymology, fasciola, a band. _ Type, F. tulipa. Pl. V., Fig. 1. Shell fusiform, elongated ; whorls round or angular; canal open; columellar lip tortuous, with several oblique folds. Oper.ulum claw- shaped. FF. gigantea of the South Seas attains a length of nearly two Fig. 81. Fasciolaria Tarentina. feet. The teoth of Fasciolaria re- oars @ semble those of Fusus Islandicus. In Buccinwm undatum, the median tooth has five, or rarely six denticles ; and Mr. Wilton 916 ' MANUAL OF THE MOLLUSCA. has observed that B. limbosum, # has the i seven cusped, 4 A | while in the females they are six cusped. Distribution, 108 species. West Indies, Moditetemmeame West Africa, India, Australia, South Pacific, Western America. Fosstl, 30 species, U. chalk—. France. TURBINELLA, Lam. Etymology, diminutive of turbo, a top. Type, T. pyrum. Pl. V., Fig. 2. Shell thick; spire short; columella with several transverse folds. Operculum claw-shaped. Fig. 70. The chank-shell (7. pyrum) is carved by the Cingalese, and reversed varieties of it, from which the priests administer medicine, are held sacred. Distribution, 70 species. West Indies, South America, At Ceylon, Philippines, Pacific, Western America. _ Fossil, 20 species. Muiocene—. Sub-genera, Cynodonta (Schum.), T. cornigera. Pl. V., Fig. 3.° Latirus (Montfort), T. gilbula. Pl. V., Fig. 4. Lagena (Schum.), T. Smaragdula, L. species. Northern Australia. CANCELLARIA, Lam. Etymology, cancellatus, cross-barred. Type, C. reticulata. Pl. V., 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. -Drpapuvs, Phi. Synonym, conohelix edentulus. (Sw.) Shell subcylindrical, spire acute; aperture narrow, linear, edentulous, excised at the base; lip thickened, rectilinear, rounded and abbreviated below.. TRICHOTROPIS, Broderip, 1829. Etymology, Thrix (trichos), hair, and tropis, keel. Type, T. borealis, Pl. VI., Fig. 8. (=? Admete, Phil., no operculum), * Cancellaria and 1 ee form a small natural family connected with cerithiada and strombide. a GASTEROPODA. 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 ; wncini 3: 1 denticulate, 2 and 3 simple (Fig. 82). Fig. 82. Trichotropis borealis. (Warrington). Lovén places T'richotropis in the same family with Velutina ; Cancellaria is very closely allied, though it wants both teeth and operculum. Mr. Couthouy describes T'richotropis cancellata as haying a muzzle like Littorina. Distribution, 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. Pyruta, Lam. Fig-shell. Etymology, diminutive of pyrus, a pear. Synonyms, Ficula, Sw. Sycotypus, Br., Cassidula, Humph. Cochlidium, Gray. Type, P. ficus. Pl. V., 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 17—35 fathoms water. (Adams.) Sub-genera, Fulgur, Montfort P. perversa. (= Pyrella, Sw. P. spirillus.) Rapana, Schum. P. bezoar, shell perforated. Operculum lamellar, nucleus external. This appears to be a Purpura. Myristica. Sw. P. melongena. Pl. V., Fig. 7. Operculum pointed, curved. L 218 MANUAL OF THE MOLLUSCA. Peis - Fusus, Lam. Spindle-shell. Synonyms, Colus, Humph. Leiostoma (bulbiformis). Sw. Strepsidura, Sw. Type, F. colus. Pl. V., Fig. 8. Shell fusiform; spire many-whorled; canal straight, long; operculum ovate, curved, nucleus apical. Pl. V., 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, &e. Sub-genera, Trophon, Montfort. F. magellanicus, Pl. IV., Fig. 16. 38 species. Antarctic and Northern seas. British — coast. d5—70 fathoms. ossil, Chili, Britain. Clavella, Sw. (Cyrtulus, Hinds), body-whorl ventricose, sud- denly contracted in front; canal long and straight. Resembling a turbinella, without plaits. 2 species. Marquesas, Panama. Fossil, Hocene. F. longzevus (Solander), Barton, &c. f Chrysodomus, Sw. F. antiquus (var.). Pl. V., Fig. 9. Canal — short; apex papillary; lingual dentition like buccinum, 12 species. Spitzbergen, Davis’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 living gasteropods. F'usus (chrysodomus) antiquus, called the red-whelk on the coasts of the Channel, and ‘‘ buckie”’ in — Scotland, is extensively dredged for the markets, being more — esteemed than the buccinwm. 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 cavity containing the oil, and the canal the wick. — (Fleming.) The reversed variety (F. contrarius, Sby.) is found in the Mediterranean, and on the coast of Spain; it abounds in — the pliocene tertiary (crag) of Essex. The /usus deformis, a similar species, found off Spitzbergen, is always reversed. Famity IITI.—Buccrnipz&. Shell notched in front; or with the canal abruptly reflected, producing a kind of varix on the front of the shell. P| Animal similar to murex; lingual ribbon long and linear GASTEROPODA. 219 (Fig. 16), rachidian teeth single, transverse, dentated in front; uncini single. Carnivorous. Buccinum, L. Whelk. Etymology, buccina, a trumpet, or triton’s-shell. Type, B. undatum. Pl. V., 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 Pisania, &c. Gault >—Miocene— Britain, France. Fig. 83. Nidamental capsules of the Whelk.* The whelk is dredged for the market, or used as bait 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. zx. B. limbosum, purpura maculosa, &c. Operculum asin fusus. About 12 species. PSEUDOLIVA, Swainson. Etymology, named from its resemblance to oliva, in form. Synonyms, Sulco-buccinum, D’Orbigny. Gastridium (Gray) G. Sowerby. * Fig, 83, From a small specimen, on an oyster-shell, in the cabinet of Albany Han. cock, Esq. The line at } represents the length of the young shell, EZ 220 MANUAL OF THE MOLLUSCA. Type, P. plumbea. Pl. V., Fig. 12. Shell globular, thick; with a deep spiral furrow.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, France, Chili. P ANOLAX (Roissy), Conrad, Lea. Etymology, an aulax, without furrow. Synonyms, Buccinanops, D’Ornigny. Leiodomus, Sw. Bullia, Gray. Types, A. gigantea, Lea. Buc. levigatum. B. semiplicata, » Pl. V., Fig. 14. Shell variable; like buccinum, pseudoliva, 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. Hocene—. North America, France. P Hatta, Risso. Etymology, halios, marine. Synonym, Priamus, Beck. Types, bulla helicoides (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). TEREBRA, Lamarck. Auger-shell. Synonyms, Acus, Humph. Subula, Bl. Dorsanum, Gray. Type, T. maculata. Pl. V., Fig. 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. : Y. Distribution, 109 species, mostly tropical. Mediterranean (1 species). India, China, Western America. Fossil, 24 species. Hocene—. Britain, France, Chili. GASTEROPODA. 221 Exsurna, Lamarck. Ivory-shell. Etymology, ebur, ivory. Synonym, Latrunculus, Gray. Type, Ki. spirata. Pl. V., Fig. 11. Shell umbilicated when young; inner lip callous, spreading and coyering the umbilicus of the adult; operculum pointed. nucleus apical. Distribution, 9 species. Red 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. Pl. V., Fig. 15. Shell like buccinum; columellar lip callons, 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. WN. obsoleta (Say) lives within the influence of fresh water and becomes eroded. WN. reticulata, L., is common on the English shores at low water, and is called the dog-whelk by fishermen. Distribution, 210 species. Low water—d50 fathoms. World- wide. Arctic, Tropical, and Antarctic Seas. Fossil, 19 species. Eocene—. Britain, &c. North America. Sub-genus, Cyllene, Gray. CO. Oweni, Pl. V., Fig. 17. Outer lip with a slight sinus near the canal; sutures channelled. West Africa, Sooloo Islands, Borneo. Fossil, Miocene, Touraine. Cyclonassa, Swainson. C. neritea, Pl. V., Fig. 16. Puos, Montfort. Etymology, phos, light. Synonym, Rhinodomus, Sw. Type, P. senticosus, Pl. V., 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.) Red Sea, Ceylon, Philip~ pines, Australia, West America. 222 MANUAL OF THE MOLLUSCA. ? RrnaicuLa, Deshayes. Etymology, diminutive of ringens, from ringo, to grin. Type, R. ringens, Pl. V., 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. 8. Wood; it appears to us very nearly allied to cinulia = avellana, D’Orbigny) in tornatellide. Purpura (Adans.), Lam. Purple. Type, P. persica, Pl. VI., 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. Pl. VL., 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 a a T crimson dye; it may be obtained by pressing on the operculum. ~ P. 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. C. lepas (Gmelin species) Pl. VI, 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. P PURPURINA (Lycett, 1847), D’Orbigny. Shell ventricose, coronated; spire short; aperture large, scarcely notched in front. Fossil, 9 species. Bath-oolite. Britain, France. The type P. rugosa, somewhat resembles purpura chocolatum (Duclos), but the genus probably belongs to an extinct group. RHIZOCHILUS, Stp. 1850. Example, R.antipathum. Founded on a species of Purpura? | y GASTEROPODA. 223 which lives on the antipathes ericoides. When adult they attach 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. Pl. VI., 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, turbinella, pseudoliva, &e. Distribution, 18 species. West coast of America. Fossil, Tertiary. Chili. M. giganteus (chorus) has the canal produced like fusus. M. cingulatum is a turbinella, and several species belong more pro- perly to lagena. PEDICULARIA, Swainson, Type, P. sicula. Pl. VI., Fig. 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. RIcINULA, Lam. Etymology, diminutive of ricinus, the (fruit of the) castor-oil plant. Example, R. arachnoides. Pl. VI., Fig. 9 (= murex ricinus, L.). Shell thick, tuberculated, or spiny; aperture contracted by callous projections on the ips. Operculum as in purpura. Distribution, 34 species. India, China, Philippines, Australia, Pacific. © Fossil, 3 species. Miocene—. France. PLANAXIS, Lam. Type, P. sulcata. Pl. VI., Fig. 6. Synonyms, Quoyia and Leucostoma. Shell, turbinated ; aperture notched in front; inner lip callous, 224 MANUAL OF THE MOLLUSCA. channelled behind; operculum subspiral (quoyia) or semi-oyate. Pi. Wil Hig, \7.. Distribution, 27 species. West Indies, Red 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 Littorinide. Maciuus, Montfort, 1810. Synonyms, Campulote, Guettard, 1759. Leptoconchus, Riippell. Type, M. antiquus. Pl. V., Figs. 19, 20. Shell, when young, spiral, thin ; aperture channelled in front ; adult, prolonged into an irregular tube, solid behind; operculum lamellar. Distribution, 4 species. Red 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. Leyenia, Gray. Cypreecassis, Stutch. Type, C. flammea. Pl. VI., Fig. 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 Fig. 84. Opere. mistaken by Gray and Adams for the teeth, which of Cassis. in this genus, and also in 7'riton, are very minute and transparent. Fig. 85. Cassis saburon. (Original). Distribution, 87 species. Tropical seas; in shallow water. West Indies, Mediterranean, Africa, China, Japan, Australia, New Zealand, Pacific, Mexico. GASTEROPODA. 225 Fossil, 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. OnIscra, Sowerby. Etymology, oniscus, a wood-louse. Synonym, Morum, Bolten. Type, O. oniscus; O. cancellata. Pl. VI., 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, Gallapagos, United States. (20 fathoms). Fossil, 8 species. Miocene. United States, Domingo. CASSIDARIA, Lam, Etymology, cassida, a helmet. Synonyms, Morio, Montfort. Sconsia, Gray. Type, C. echinophora. Pl. VI., Fig. 13. Shell yentricose ; canal produced, rather bent. No operculum. Distribution, 6 species. Mediterranean. Fossil, 10 species. HKocene—. Britain, France, &c. BACHYBATHRON, Gaskoin. Shell small, oblong, striated with lines of growth; spire small, depressed, with channelled suture; aperture with callous denticulated lips, hke Cyprea. Distribution, 3 species. Fig. 86. Dolium perdiz. (Original), Do.ivum, Lam. The Tun. Type, D. galea. Pl. VI., Fig. 12, Shell ventricose, spirally furrowed; spire small; aperture very large; outer lip crenated. No operculum. Teeth 3, 1, 3. Fig. 86. The genus Macgillivrayia, formerly assigned to the Atlantide, belongs here. It comprises the larva forms of several species of Dolium. L3 ~ 226 MANUAL OF THE MOLLUSCA. Distribution, 14 species. Mediterranean, Ceylon, China, Aus- tralia, Pacific. Fossil, 7 species. (? Chalk. Britain). Tertiary. South Europo. Sub-genus, Malea, Valenc. (D. personatum), outer lip thickened and denticulated ; inner lip with callous prominences. Harpa, Lam. Harp-shell. Type, H. ventricosa. Pl. VI., Fig. 11. (= Buc. harpa, L.) Shell ventricose, 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—. France. CoLUMBELLA, Lam. Etymology, diminutive of colwmba, a dove. Type, OC. mercatoria. Pl. VI., Fig. 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, Gallapagos, California. Small, prettily- * D. perdiz, L. species. 4 natural size (after Quoy). Vanicoro, Pacific. The ) tobescis is exserted, and the siphon recurved over the front of the shell. SE ee ee GASTEROPODA. 227 matked shells; living in shallow water, on sandy flats, or congregating about stones. (Adams.) Fossil, 8 species. Tertiary. (The British species are pisanic.) Sub-genus, Columbellina, D’Orbigny. 4 species. Cretaceous. France, India. Oniva, Lam. Olive, rice-shell. Type, O. porphyria. Pl. VI., 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. 8 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 le in the suture and furrow. The — placed near the tips of the tentacles. The olives 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, France, &c. Sub-genera. Olivella, Sw. O. jaspidea, Pl. VI., Fig. 19. Animal with small, acute frontal lobes. Operculum nucleus sub-apical. Scaphula, Sw. = Olivancillaria, D’Orbigny, Pl. VI., Fig, 18, Frontal lobes large, rounded, operculate. Agaronia, Gray. O. hiatula, Pl. VI., Fig. 17. No eyes or tentacles. Frontal lobes moderate, acute. ANCILLARIA, Lam. Etymology, anctlla, a maiden. Types, A. subulata, Pl. VI., Fig. 20. A. glabrata, Pl. VI., 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. (D’Orbigny.) In A. glabrata, a space resembling an umbilicus, is left between the callous inner lip and the body-whorl. 228 MANUAL OF THE MOLLUSCA. Distribution, 23 species. Red Sea, India, Madagascar, Aus- tralia, Pacific. Fossil, 21 species. Eocene—. Britain, France, &e. Famity ITV.—Conipm, Cones. Shell inversely conical; aperture long and narrow; outer lip notched at or near the suture ; 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. Gulls 2. Lingual teeth (wncini?) in pairs, elongate, subulate, or hastate. Conus, L. Cone-shell Types, C. marmoreus, Pl. VII., Fig. 1. C. geographicus, antediluvianus, &c. 4 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, Jaya, &c. The cones range northward as far as the Mediterranean, and southward to the Cape; but are most abundant and yaried 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 (C. aulicus) bite when handled; they are all predatory. (Adams. ) Sub-genus Conorbis, Sw. C. dormitor, Pl. VIL, Fig. 2. Eocene—. Britain, France. Fig. 88,* PLEUROTOMA, Lam. Etymology, pleura, the side, and toma, a notch. Synonym, Turris, Humphrey. Types, P. Babylonica, Pl. VII., Fig. 3. P. mitreeformis, &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. Greenland, Britain, 17; Mediterranean, 19; Africa, 15; Red Sea and India, 6; Chinu, 90; Australia, 15; Pacific, 0? West America, 52; West * Fig. 88. Lingual teeth of Bela turricula (after Lovén). GASTEROPODA. 929 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. Sub-genera, Drillia, Gray. D. umbilicata, canal short. Clavatula, Lam., canal short, operculum pointed, nucleus in the middle of the inner edge. O. mitra, Pl. VII., Fig. 4. Tomella, Sw., canal long; inner lip callous near suture. T. lineata. 2 OUionella, Gray. C. sinuata, Born species. (= P. buccinoides), freshwaters, Africa. Mangelia, Leach (not Reeve). Apertural slit at the suture; no operculum, M. teeniata, Pl. VII., Fig. 5. Greenland, Britain, Mediterranean. Bela, Leach. Operculum nucleus apical. B. turricula, Pl. VII., Fig. 6. Defrancia, Millet,* no operculum. OD. linearis, Pl. VIL, Fig. 7. - 2 Lachesis, Risso, L. minima, Pl. VII., Fig. 8, apex mam- millated ; operculum claw-shaped. Mediterranean, South Britain, Japan. In shallow water. Daphnella, Hinds. D. marmorata, New Guinea. (Bue. junceum. L, clay). Borsonia, Edwards. 2 species recent; tropical seas. fossil, 6 species. Tertiary. Europe. CiTHARA, Schumacher. Etymology, cithara, a guitar. Synonym, Mangelia, Reeve (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; outer lip margined, denticulated within; inner lip finely striated. Operculum. Distribution, above 60 species of this pretty little genus were discoyered by Mr. Cuming in the Philippine Islands. Famity V.—VoLvrTipa. Shell turreted, or convolute; aperture notched in front ; 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, 8, Hanley, Defrancia is synonymous with Mangelia, 230 MANUAL OF THE MOLLUSCA, on the tentacles, or near their base. Lingual ribbon linear; rachis, toothed ; pleurce, unarmed. Fig, 89.* Votuta. L. Volute. Type, V. musica, Pl. VII., Fig. 9. Synonyms, Cymbiola, Harpula, Sw. Volutella, 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 hebreea fill the nuclei of their spires with solid shell. V. brasiliana forms nidamental capsules 38 inches long. (D’Orbigny.) In V. angulata the mantle is produced into a lobe on the left side, and over- Fig. 90. Voluta laps the shell. (Wilton). Distribution, 70 species. West Indies, Cape Horn, West Africa, Australia, Java, Chili, Fossil, 80 species. Chalk—,. India, Britain, France, &e. Sub-genera, Volutilithes, Sw. Spire pointed, many-whorled, columella plaits indistinct. V. spinosus, Pl. VII., Fig. 10. Living, 1 species (V. abyssicolw), dredged at 1382 fathoms; off the Cape. (Adams. ) Fosstl, Eocene. Britain, Paris. Scaphella, Sw. Fusiform, smooth, Example, V. magellanica. * Fig, 80. Vi undulata, Lam, } Australia, (From Quoy and Gaimard,) i aaa tel el tT, EE tn OS ® il el eC de = GASTEROPODA. 231 Fossil, V. Lamberti, Crag, Suffolk. Melo, Brod. Large, oval; spire short. Type, M. diadema, Pl. VII., Fig. 11. New Guinea, 8 species, CymBA, Broderip. Boat-shell. Synonym, Yettis (Adans.), Gray. Type, C. proboscidalis, Pl. VII., Fig. 12, and Fig. 91 (= V. cymbium, L.). Shell like voluta; 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 ovyo-viviparous, and the young animal is very large when born ; the nucleus becomes partly concealed by the growth of the shell, Distribution, 10 species. West Africa, Lisbon. Fig. 91. Cymba, Mitra, Lam. Mitre-shell. Synonyms, Turris, Montfort. Zierliana, Gray. Tiara, Sw. Types, M. episcopalis, Pl. VII., Fig. 138. M. vyulpecula Fig. 14. Shell fusiform, thick; spire elevated, acute; aperture small, notched in front; columella obliquely plaited ; operculum yery sinall. The anitnal has a very long proboscis; it emits a purple liquid, having a nauseous odour, when irritated. The eyes aro placed on the tentacles, or at their base. Range, from low water to 15 fathoms, more rarely in 15—80 fathoms. Distribution, 420 species. Philippines, India, Red 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, France, &c. Sub-genera. Imbricaria, Schum. (concelix, Sw.) Shell cone-shaped. I. conica, Pl. VII., Fig. 15. Cylindra, Schum. (Mitrella, Sw.) Shell olive-shaped. C. crenulata, Pl. VII., Fig. 16. 282 MANUAL OF THE MOLLUSCA. VoLvaRIA, Lam. Etymology, vowwa, a wrapper. Type, V. bulloides, Pl. VII., Fig. 17. Shell cylindrical, convolute : spire minute; aperture long and narrow; columella with three oblique plaits in front. Distribution, 29 species, tropical seas. Fossil, 6? species. Eocene. Britain, France, MARGINELLA, Lam. Etymology, diminutive of margo, a rim. Synonyms, Porcellana (Adans.), Gray. Persicula, Schum. Types, M. nubeculata, Pl. VII., Fig. 18. M. persicula, Fig. 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 cyprza. Distribution, 189 species. Tropical, West Indies, Brazil, Mediterranean (1 small species), West Africa, China, Australia. Fossil, 30 species. EHocene—. France, &c. Sub-genus, Hyalina, Schum. Outer lip scarcely thickened. Type, voluta pallida, Montfort, West Indies. Famity VI.—Cypraipa. 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 cayity; rachis 1 toothed; wncint 3. In Ovulum the teeth are 2. 1. 2. the outermost broad, with pectinated margins. Lovén describes the Cypreeidee as having a short, non- retractile muzzle, and places them between the Naticide and Lamellaria. The cowries inhabit shallow water, near shore, feeding on zoophytes. Cyprma, L. Cowry. Etymology, Cypris, a name of Venus. Types, C. tigris, C. mauritiana Pl. VII., Fig. 20. . ——- GASTEROPODA. 233 Shell ventricose, conyolute, covered with 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 lp, 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 oyer the whole shell, by which the spire is entirely concealed. There is usually Fig. 92. Cyprea, a line of paler colour, which indicates young. where the mantle lobes met. Cyprea annulus is used by the Asiatic Islanders to adorn their Fig. 93. 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 (C. moneta) is also a native of the Pacific and Tastern 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 moye- 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, Gray. OC. Capensis, Pl. VEE. Hig. 29; Apertural plaits continued regularly over the margin of the canal. Iuponia, Gray. C. algoénsis, Pl. VII., Fig. 22. Inner lip irregularly plaited in front. Trivia, Gray. C. europea, Pl. VII., Fig. 23; es 93, and 15, B. Small shells with striz extending over the back. (Uncini: 1st denticulate, 2, 3, simple.) * Fig 92. Cyprea testudinaria, L., young, China. + Fig. 93. Trivia Europea, Mont. From the “ British Mollusca,” by Messrs. Forbes and Hanley, 254 MANUAL OF THE MOLLUSCA. Distribution, 30 species. Greenland, Britain, West Indies, Cape, Australia, Pacific, West America. ERATO, Risso. Etymology, Erato, the muse of love-songs and mimicry. Type, E. levis, Pl. VII., Fig. 24. Shell minute ; like marginella ; lips minutely crenulated. Animal like trivia. Distribution, 11 species. Britain, Mediterranean, West Indies, China. Fossil, 2 species. Miocene—. France, Britain (Crag). Ovutum, Lam. Etymology, diminutive of ovwm, an egg. Synonym, Amphiceras, Gronoy. Types, O. Ovum, Pl. VII., Fig. 25. O. gibbosa and verrucosa. Shell like cyprea ; inner lip smooth. Distribution, 36 species. Warm seas. West Indies, Britain, Mediterranean, China, West America. Fossil, 11 species. Eocene—. France, &c. Sub-genus. Calpurna, Leach. O. volva (‘‘ the weaver’s shuttle”). Aperture produced into a long canal at each end. Foot narrow, adapted for walking on the round stems of the gorgonie, &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). Radius (Montfort) Schum. — Ovulum yolva Section B. HonostomMATA. 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 bya 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- a 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 has a notched aperture, and aporrhais, a canal. ‘ ee GASTEROPODA. 235 FAMILY I.—NATICIDA. Shell globular, few-whorled ; spire, small, obtuse; aperture semi-lunar ; lip acute; pillar often callous. Fig. 94. Natica monilifera (Wilton). Animal with along retractile proboscis ; lingual ribbon linear ; rachis 1 toothed; wncini 3 (as in Fig. 94); foot very large; mantle-lobes largely developed, hiding more or less of the shell. Species all marine. Natica (Adans.), Lamarck. Synonym, Mamilla, Schm. Cepatia, Gray. Nacca, Risso. Type, N. canrena, Pl. VIII., Fig. 1. Shell thick, smooth; inner lip callous; umbilicus large, with a spiral callus; epidermis thin, polished ; operculum sub-spiral. Animal blind; tentacles connate with a head veil; front of the large foot provided with a fold (mentm), reflected uponand protecting the head; operculigerous lobe large, covering part of the shell ; jaws horny; lingual Fig. 95. Natica.* ribbon short; branchial plume single. The coloured markings of the naticze are very indestructible ; they are frequently preserved on fossils. The natice 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 agglutinated 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. Deyonian—. South America, North America, Europe, India. Sub-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, communicated by Joshua Alder, Esq 236 MANUAL OF THE MOLTUSCA. Operculum, horny. Neverita, Risso. N. Alderi. Fig. 95. Lunatia, Gray. N. Ampullaria. Perforation simple; epider- mis dull, olivaceous. Northern seas. Globulus, J. Sby. (Ampulina, Deshayes not Bl.) N. Sigaretina. Pl. VIII., Fig. 2, Umbilicus narrow (rimate), lined by a thin callus. Fossil, Hocene. Britain, Paris. . Polinices, Montfort (naticella, Guild.}, N. mammilla. Shell oblong; callus very large, filling the umbilicus. Cernina, Gray, N. fluctuata. Pl. VIII., Fig. 3. Globular, imperforate ; inner lip callous, covering part of the body-whorl. Naticelia, Miller. 19 species. Fossil, Trias, S. Cassian. DESHAYESIA, Raulin Miocene, France. Some additional species have been found with a similar oblique aperture and corrugated inner lip. Baron Ryckholt has described a species (D. Raulini), from the Devonian, Belgium. ‘The relation of the genus is uncertain. NATICELLA, Minster. 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. 2387) and Fossarus (p. 253), and appears to form with them a litle group nearly related to Lacuna (p. 255). SIGARETUS (Adans.), Lamarck. Synonyms, Cryptostoma, Bl. Stomatia, Browne. Type, 8. haliotoides. Pl. VIII., Fig. 4. Sheil 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. Distribution, 81 species. West Indies, India, China, Peru. | Fossil, 10 species. Eocene—. Britain, France, South America. Sub-genus. Naticina, Gray. N. papilla, Pl. VIIL, Fig. 8. Shell ventricose, thin, perforated. West Indies, Red Sea, China, North Australia, Tasmania. Hocene, Paris. Fe Le ee ee a esis GASTEROPODA. 237 LAMELLARIA, Montagu. Etymology, lamella, a thin plate. Synonyms, Marsenia, Leach. Coriocella, Bl. Type, L. perspicua. Pl. VIII., 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 wncini 3, similar; or one very large. Distribution, 10 species. Norway, Britain, Mediterranean, New Zealand, Philippines. Fossil, 2 species. Plocene—. Britain (Crag). Narica, Recluz. Synonyms, Vanicoro, Quoy. Merria, Gray. Leucotis, Sw. Type, N. cancellata. Pl. VIII., 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, Vanikoro, Pacific. Fossil. 4 species, Gault—. (D’Orbigny.) Britain, France. VELUTINA, Fleming. Etymology, velutinus, velvety (from vellus, a fleece). Type, V: levigata. Pl. VIII, Fig. 7. 7 Fig. 96. Velutina levigata (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 tae mantle developed all round, and more or less reflected over the shell ; 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. 16, B). 238 MANUAL OF THE MOLLUSCA, Distribution, 4 species. Britain, Norway, North America, Icy Sea to Kamtschatka. Fossil, 3 species. Pliocene—.. Britain. Sub-genus. Otina (Gray). Y. 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. laevigata is sometimes brought in on the fishermen’s lines (off Northumberland), generally adhering to Alcyoniwm 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 J].—PYRAMIDELLIDA. 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 ; 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 chemnitzia.* Tornatella, usually placed in or near this peieh pS is opistho- branchiate. | PYRAMIDELLA, Lam. Etymology, diminutive of pyramis, a pyramid. Synonyms, Obeliscus. Humphrey. (P. dolabrata., Pl. Be: Fig. 11.) Syrnola, Adams, 1860. Type, P. auris-cati. Pl. VIII., 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 pyramidellz bears some resemblance to cancellaria. * “The Pyramidellide 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 us appertaining to past ages than the present epoch,”—Fordes, ae ee eee GASTEROPODA. 239 Distribution, 111 species. "West Indies, Mauritius, Australia. Fossil, 12 species. Chalk—. France, Britain. OposTomMIA, Fleming, 1824. Etymology, odous, a tooth, and stoma, mouth. Type, O. plicata. Pl. VIII., Fig. 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. Distribution, Pspecies. Britain, Mediterranean, Red Sea, Australia. Fossil, 15 species ? Eocene—. Britain, France. Very minute and smooth shells, having the habit of rissoe, 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-cabinet,”’ 1780-95. Synonyms, Turbonilla, Risso. Parthenia, Lowe. Pyramis and Jaminea, Br. Monoptigma, Lea, part. Amoura, Moller. Type, C.elegantissima. Pl. VIII., Fig. 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. Distribution, 32 species. Britain (4 species), Norway, Medi- terranean. Probably world-wide. Range from low water to 90 fathoms. Fossil, 240 species. Silurian—. Britain, France, &c. The ‘‘melaniz” of the secondary rocks are provisionally referred to this genus. Those of the paleozoic strata to loxonema. Sub-genera. Eulimella, Forbes. E. scillee, 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 MOLLUSCA. Evia, Risso, 1820. Etymology, eulimia, ravenous hunger Synonym, Pasithea, Lea. Type, HE. polita. Pl. VIII., 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 reds e siphonal fold. The eulimes 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, Risso (= Bonellia, Deshayes). N. tere- bellatus, Lam. species. Axis perforated. Fossil, 3 species. Eocene—. Paris. Distribution, 5 species. China, West America. (Cuming.) MonorrTiemA, 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) vy. Chemuitzia. Acuis, Lovén. Ltymology, A, without, kleis, a projection. Synonym, Alyania, Leach (not Risso). Type, A. supranitida. Wood. A. ascaris, Turt. Pl. im... Fig. 4. Shell minute, like turritella ; spirally striated ; aperture oval ;. outer lip prominent; axis slightly rimate; operculate; apex sinistral. | GASTEROPODA. 241 Animal with a long retractile proboscis; tentacles close together, slender, inflated at the tips; eyes immersed at the bases of the tentacles; operculum lobe ample, unsymmetrical ; foot truncated in front. Ranges to 80 fathoms water. 5 British species, Norway. Fossil. Pspecies. Pliocene—. Britain (Crag). StryLopryema, Adams. 1860. Shell pupiform, semi-transparent; with slightly convex whorls. Aperture sub-quadrate. MyontA, Adams. Shell ovate, turreted; white, thin, with slightly convex whorls. Aperture oblong. LEvcoTINA, Adams. Shell like last, but with last whorl ventricose ; with minute dots. STILIFER, Brod. Exampie, 8. astericola. Pl. VIII., Fig. 15. Synonym, Stylina, Fleming. 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. LoxoneEMA, 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. MAcROCHEILUS, Phillips. Etymology, macros, long, and cheilos, lip. Synonym, Polyphemopsis, Portlock. Shell thick, ventricose, buccinoid; aperture simjle, effuse M 242 MANUAL OF THE MOLLUSCA. below; outer lip thin, inner lip wanting, columella callous, shghtly tortuous. ' Type, M. arculatus, Schlotheim species. Devonian. Hifel. Distribution, 1 species (M. Japonicus), Korea Straits. Fossil, 12 species. Devyonian— Carboniferous. Britain, Belgium. Famity IIJ.—CERITHIADE. Cerites. Shell spiral, elongated, many-whorled, frequently varicose ; aperture channeled 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 Cerithiade ; the teeth are broad, as in Melaniade, with incuryed and dentated summits. In Cerithidiwm 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. VIII., 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. Pl. VIIL., Big a6? tt: | Distribution, 136 species. World-wide, the typical species tropical. Norway, Britain, Mediterranean, West Indies, India, Australia, China, Pacific, Gallapagos. Fossil, 460 species. Trias—. JBritain, France, United States, &e. Sub-genera. Rhinoclavis, Sw. C. vertagus. Canal long, © bent abruptly ; operculum, sub-spiral. , Bittiwm, Leach. ©. reticulatum, Pl. VITI., Fig. 17. Small — northern species, ranging from low water to 80 fathoms. MY Triforis, Deshayes. C. perversum, Pl. VIII., Fig. 18. 30 — species. Norway—Australia. . 4 Fossil, Kocene—. Britain, France. Shell sinistral; anterior and posterior canals tubular. Tho ~ third canal is only accidentally present, forming part of a varix. — Cerithiopsis, Forbes. C. tuberculare, Britain. GASTEROPODA. 948 Shell like bittiwm; proboscis retractile ; operculum pointed, nucleus apical. Range 4—40 fathoms. PoTAMIDES, Brongniart. Fresh-water Cerites. Etymology, potamos, a river, and ides, patronymic termination. Type, P. Lamarckii, Brong. (= Cerit. tuberculatum, Brard.) Example, P. mixtus. Pl. VIII., Fig. 19. Synonyms, Tympanotomus, Klein, C. fuscatum, Africa. Pirenella, Risso, C. mammillatum, Pl. VIII., Fig. 22. Shell like cerithiwm, but without varices in the very numerous typical fossil species; epi- /\X 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 ampullaria, venus, purpura, ostrea, &c. (Major W. E. Baker.) Fossil (species included with cerithium), Eocene—. Europe. Sub-genera, Cerithidea, Sw., C. decollata, Pl. VIII., Fig. 24. Aperture rounded; lp expanded, flattened. Inhabit salt marshes, mangrove swamps, and the mouths of 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). Distribution, India, Ceylon, Singapore, Borneo, Philippines, Port Essington. Terebralia, Sw. Cerith. telescopium, Pl. VIII., 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 nerinea (Fig. 98). India, North Australia. 7’. telescopium is so abundant near Calcutta as to be used for barning into lime ; great heaps of it are first exposed to the sun, to kill the animals. They have been brought alive to England. (Benson. ) Pyrazus, Montfort. Cerit. palustre, Pl. VIII., Fig. 20. Shell with numerous indistinct varices ; canal straight, often tubular; outer lip expanded. India, North Australia. * C. obtusa, Lam. sp. copied from Adams, 5 mM 2 Fig. 97. Cerithidea,* 244 MANUAL OF THE MOLLUSCA. Cerith. radulum and granulatum of the West African rivers approach yery near the 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 batin, resembles this section, and retains its spiral red bands. NerinZ@a, Defrance. Etymology, nereis, a sea-nymph. Example, N. trachea. Fig. 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—U. chalk. Britain, France, Germany, Spain, and Portugal. They are south ; and usually occur in calcareous strata, asso- ciated with shallow-water shells. (Sharpe.) Sub-genera. 1. Nerinea. Folds simple: 2—3 on the columella ; 1—2 on the outer wall; columella solid, or perforated. Above 50 species. 2. Nerinella (Sharpe), columella solid; folds simple ; columellar, 0—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, Fig, 93,* usually with 3 folds; outer wall with 1—3 folds, some of them complicated in form. P FASTIGIELLA, Reeve. Type, ¥. carinata, Reeve. most abundant, and attain the largest size to the — Shell like turritella; aperture with a short canal in front (Cuming Museum, and British Museum). Fossil, Eocene. Paris (Cerithiwm rugosum, Lam.). AporruAtrs, Aldrovandus. Etymology, wporrhais (Aristotle), ‘‘ spout-shell,” from aporrheo, to flow away. * Fig. 98. Nerimea trachea, Desl., partly ground down to show the form of the interior. Bath oolite, Ranville. Communicated by John Morris, Esq. GASTEROPODA. 245 Synonym, Chenopus, Philippi. Type, A. pes-pelecani. Pl. IV., Fig. 7, and Fig. 99. Shell with an elongated spire ; whorls numerous, tuberculated ; aperture narrow, with a short canal in front; outer lip of the adult expanded and lobed o1 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; » Fig. 99.* lingual ribbon linear; teeth single, hooked, denticulated ; uncini 38, the first transverse, 2 and 3 claw-shaped (Fig. 100). The dentition of Aporrhais is most like Strombus and Carinaria ; and quite unlike the Cerithiade with which it has been placed, Fig. 100. Aporrhats 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. Range 100 fathoms. Fossil; see Pteroceras 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-pelcam, L., from a drawing by Joshua Alder, Esq., in the “ British Mollusca.” ' 246 MANUAL OF THE MOLLUSCA. STRUTHIOLARIA, Lam. Etymology, struthio, an ostrich (-foot), from the form of its aperture. Type, 8. straminea, Pl. IV., Fig. 6. Shell turreted ; whorls angular ; aperture truncated in front; columella very oblique; outer lp prominent in the middle, reflected and thickened in the adult; inner lip callous, expanded; operculum claw- shaped, 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. : Operculum of (IGener.) Strutmolariaa Distribution, 5 species. Australia and New Zealand, where alone it occurs sub-fossil. Faminty TVY.—MELANIADA. Sheil spiral, turreted ; with a thick, dark epidermis ; aperture often channeled, or notched in front ; outer lip acute ; operculum horny, spiral. The spire is often extensrvely eroded by the acidity of the water in which the animals live. Animal 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. Etymology, melania, blackness (from melas). Zype, M. amarula. Pl, VIII., Fig. 25. Synonyms, Thiara, Megerle. Pyrgula, Crist. Shell turreted, apex acute (unless eroded); whorls orna- mented with strize or spines; aperture oval, pointed above; outer lip sharp, sinuous; operculum subspiral. Pl. VIIL., Fig. 25.* Distribution, 361 species. South Europe, India, Philippines, Pacific Islands. Distinct groups in the southern States of North America. GASTEROPODA. 247 Fossil, 25 species. Wealden—. Europe (vy. chemnitzia). Sub-genera. Melandtria, Bowdich. M. fluminea.* Pl. VIII., Fig. 26. Aperture somewhat ‘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. Sowerbii (cerit. melanoides, Sby.), of the Woolwich sands. Old World, India, Philippines. Vibex, Oken, V. fuscatus, Pl. VIII., Fig. 29. YV. auritus. West Africa. Whorls spirally ridged, or muricated; aperture broadly channeled in front. Ceriphasia, Sw., C. suleata. 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. VILI,, Fig. 27. United States. Aperture produced into a spout in front. Melatoma, Anthony (not Sw.) M. altilis. Shell like anculotus; with a deep slit at the suture. United States. Anculotus, Say. A. premorsus. Pl. VIII., Fig. 28. Shell globular ; spire very short; outer lip produced. United States. Amnicola, G. and H. A. isogona. Pl. [X., Fig. 23. United States; inhabits the fresh waters of New England, gregarious on stones and submerged plants. Chilostoma, Desh. M. marginaia, Eocene. Paris. Peristome thickened externally, all round. Clea, Bens. C.annesleyi. South India. PALUDOMUS, Swainson. Etymology, palus, a marsh, and domus, home. Synonyms, Tanalia, Gray. Hemimitra, Sw. Type, P. aculeatus, Gm. species. Pl. IX., Fig. 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, lke paludina. * This is a good section of melanza, but Mr. Gray’s type does not well represent it, being more like a pirena in the form of its aperture. 248 MANUAL OF THE MOLLUSCA. MELANOPSIS, Lam. Types, M. buccinoides, M. costata. Pl. VIII., Fig. 30. Shell body-whorl elongated ; ‘spire short and pointed; aper- ture 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. Pl. VIII., Fig. 31. Spire elongated, many-whorled ; outer lip of Does l Fig. 102. Pirena atra. (Wilton.) the adult produced. Teeth 3. 1. 3, as in Fig. 102. Distribution, 4 species? South Africa, Madagascar, Ceylon, Philippines. FAMILY V.—IURRITELLIDA. 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. TURRITELLA, Lam. Etymology, diminutive of turris, a tower. Synonyms, Terebellum, Torcula, Zaria, and Eglisia (Gray.) Type, T. imbricata. Pl. [X., Fig. 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. Ranging 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. eee ee rT OO ——— a eS ee eee ee a ee GASTEROPODA. 249 Sub-genera. Proto, Defr., P. cathedralis, Pl. [X., Fig. 3, aperture truncated below. Mesalia, Gray, M. sulcata (var.), Pl. [X., Fig. 2. Greenland —South Africa. Fossil, Eocene. Britain, France. Czcum, Fleming. Synonyms, Corniculina, Minster. Brochus, Bronn. Odonti- dium, Phil. Type, C. trachea, Pl. [X., 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, 0; uncini, 2, the inner broad and serrulated. Distribution, Britain, 11 species, 10 fathoms. Mediterranean. Fossil, 4 species. Eocene—. Britain, Castelarquato. VERMETUS, Adanson. Worm-shell. Synonyms, Siphonium, Gray. Serpuloides, Sassi. Types, V. lumbricalis, Pl. [X., 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. ? Sub-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 P Petaloconchus, 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. SILIQUARIA, Brug. Etymology, siliqua, a pod. Typo, 8, anguina, Pl. [X., Fig. 8. Shell tubular; spiral at first, irregular afterwards; tube with a continuous longitudinal slit. Distribution, 8 species. Mediterranean, North Australia. Found in sponges. Fossil, 10 species. Eocene—. France, &ce. M 3 250 MANUAL OF THE MOLLUSCA. ScaLaria, Lam. Wentle-trap. Etymology, scalaris, like a ladder. Type, S. pretiosa, Pl. [X., Fig. 9. (= T. scalaris, L.) Shell mostly pure white and lustrous; turreted; many- whorled; whorls round, sometimes separate, ornamented wth numerous transverse ribs; aperture round; peristome con- tinuous; operculum horny, few-whorled. Animal with a retractile proboscis-like mouth; tentacles close together, long and pointed, 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 bulla; teeth 0; uncini nume- rous, simple; sexes distinct; predacious? Range from low water to 80 fathoms. The animal exudes a purple fluid when molested. Distribution, 104 species. Mostly tropical. Greenland, Norway, Britain, Mediterranean, West Indies, China, Australia, Pacific, West America. Fossil, nearly 100 species. Coral-rag—. Britain, North America, Chili, India. Famity VI.—LItTToRINIDA. 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 alge. Lirrorina, Férussac. Periwinkle. Etymology, littoralis, belonging to the sea-shore. Type, L. littorea, Pl. [X., Fig. 10. Shell turbinated, thick, pointed, few-whorled; . aperture rounded, outer lip acute, columella rather flattened, imperforate, operculum pauci-spiral, Fig. 103. Lingual teeth hooked and trilobed; uncini Fig 103. hooked and dentated (Fig. 104). Distribution, 131 species. The periwinkles are found on the sea hore in all parts of the world. In the Baltic they live GASTEROPODA. 251 within the influence of fresh water, and frequently become dis- torted ; similar monstrosities are found in the Norwich crag. X Fig. 104. Littorina littorea. (Warington.) The common species (ZL. littorea) is oviparous ; it inhabits the lowest zones of sea-weed between tide-marks. An allied species y, rostrum or muzzle, &, buccal mass. g, nervous ganglia (reproductive orifice, on the right side). S, salivary gland. @, esophagus, Z, lingual coil. m, shell-muscle, é, branchia or gill. c, heart. n, aorta. e, stomach, SJ, liver. h, biliary canal, t, intestine, a, anus. 0, ovary. . d, oviduct. u, uterus. o', ovarian orifice, z, renal organ. y, mucus gland, Fig. 105. Littorina littorahs 9: (after Souleyet), Animal removed from its shell; branc cavity and back laid open. (L. rudis) frequents a higher region, where it is scarcely reached by the tide; it is viviparous, and the young haye a hard shell 292 MANUAL OF THE MOLLUSCA. before their birth, in consequence of which 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 lingualcanal — of the periwinkle passes from the back of the mouth under the © cesophagus for a short distance, then turns up on the right side, and terminates in a coil (like spare rope) resting on the plaited portion of the gullet. It is 24 inches long, and contains about 600 rows of teeth; the part in use, arming the tongue, comprises about 24 rows.* The dental ribbon of Risella 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 Risella. (Wilton.) The central tooth should be pointed, not blunt as in the figure. referred to turbo belong to this genus, and especially to the section tectaria. Sub-genera. Tectaria, Cuvier, 1817 (= Pagodella, Sw.), L. pagodus, Pl. 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, Pl. IX., Fig. 13. | Shell trochiform or naticoid; porcellanous; columella per- — forated ; inner lip worn or toothed; operculum horny, few- — whorled. a * In Fig. 105 is shown the manner in which a gasteropod may be laid out for F exan.ination, 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 india 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. iy GASTEROPODA. 253 Distribution, Philippines, West America. Fossarus (Adans.), Philippi. F. sulcatus, Pl. [X., Fig, 12, Synonym, Phasianema, Wood. Shell perforated ; inner lip thin; operculum not spiral. Distribution, Mediterranean. Fossil, 3 species. Miocene—. Britain, Mediterranean. Risella, Gray. Lit., melanostoma, Pl. IX., Fig. 14. Shell trochiform, with a flat or concave base; whorls keeled ; aperture 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. SoLaRriIum, Lam. Stair-case shell. Etymology, solarium, a dial. Synonyms, architectoma, Bolten. Philippia, Gray. Helico- cryptus, D’Orbigny ? Type, 8. 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, Kast Africa, India, China, Japan, Australia, Pacific, West America. Fossil, 56 species. HKocene—. Britain, &c. 26 other species (oolites—chalk) are provisionally referred to this genus; the cretaceous species are nacreous (vy. 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.) §. 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 (caleuliformis) Dunker, 1851. JLias, Gottingen. This name was proposed for the depressed Euomphali of the Lower Oolites, of which there are several species in Normandy . and England. ni * Operculum of 8. patulum, Lam. 3, from Deshayes. 254 MANUAL OF THE MOLLUSCA. Shell usually sinistral, flat, or concave above; aperture quadrangular, Platystoma (Suessi) Hornes, 1855. Trias, Hallstadt. Shell discoidal, sinistral? sculptured; peristome suddenly expanded, plain; aperture with an inner rim, circular, and deflected (upwards) at right angles to the plane of the shell. Several examples haye occurred. Philippia (lutea) Gray, has a multi-spiral operculum, and the animal is like Trochus. (Philippi.) Paludestrina (lapidum) D’Orbigny part. Fresh waters of South America. Shell conic, few-whorled, epidermis green ; aperture oblique, peristome abruptly reflected; operculum claw-like. The typical species appear to be Melaniade, but some small shells like Hydrobia have been included in the genus. PuHorvs, Montfort. Carrier-shell. Etymology, phoreus, a carrier. Synonyms, Onustus, Humph., Xenophorus, Fischer. Examples, P. conchyliophorus, Born. P. corrugatus, Pl. X., Hie, 1. Shell trochiform, concave beneath; whorls flat, with foliaceous or stellated margins, to which shells, \ stones, &c., are usually affixed; aperture very oblique, not pearly; outer lp thin, much produced above, receding far beneath; operculum horny, im- bricated, nucleus external, as in purpura and palu- domus, with the transverse scar seen through it, Fig. 108. (Museum Cuming.) Animal with an elongated (non-retractile?) proboseis; ten- tacles long and slender, with sessile eyes at their outer bases; sides plain ; foot narrow, elongated behind.—Adams. Related 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, and to scramble over the ground, like the strombs, rather than glide evenly. Distribution, 9 species. West Indies, India, Malacca, Philip- pines, China, and West America. . Fossil, 15 species. Chalk ?—Eocene—. Britain and France. Fig. 108. GASTEROPODA. 256 Shells extremely like the recent phorus, are met with even in the carb. limestone and lias. Lacuna, Turton. Etymology, lacuna, a fissure. Type, L. pallidula (Pl. [X., 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. Range, low water—s0 fathoms. Distribution, 16 species. Northcrn shores, Norway, Britain, Spain. Fossil, 1 species. Glacial beds, Scotland. Litiopa, Rang. Etymology, litos, simple, ope, aperture. Type, L. bombyx (Pl. IX., Fig. 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). Rissoa, Frémenville. Etymology, named after Risso,* a French zoologist. Type, R. labiosa (Pl. TX., Fig. 17). Synonym, Cingula, Flem. Shell minute, white or horny; conjcal, pointed, many-whorled; smooth, ribbed, or cancellated; aperture rounced; 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 side. Lingual teeth single, sub-quadrate, heoked, dentat:d; 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 of fucus and zostera. Distribution, about 70 species. Universally distributed, but * It is much to be regretted that some modern naturalists have tried to find out and bring nt» use the obscure genera of Risso, and the worthless fabrications of Montfort and Rafinesque, which had better have remained unknown. 956 MANUAL OF THE MOLLUSCA. most abundant in the north temperate zone. North America, West Indies, Norway, Britain, Mediterranean, Caspian, India, &c. issoa parva adheres to sea-weeds by threads, like litiopa. (Gray. ) Fossil, 100 species.. Permian—. Britain, France, &c. Sub-genera. Rissoina, D’Orbigny. Aperture channeled in front. 66 living species. Fossil (10 species Bath ovlite.— Britain.) = Tuba, Lea? America. Hydrobia, Hartm. (=Paludinella, Loyén.) Shell smooth ; foot rounded behind; operculigerous lobe without filament. Type, littorina ulyee (Pl. [X., Fig. 18). Distribution, 50 species. Fossil, 10 species. Wealden—. "Benen: &e. 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. Nematura, Benson. N. deltz (Pl. [X., Fig. 21.) Aperture contracted; peristome entire; operculum pauci-spiral. Fossil, Eocene. Isle of Wight. Jeffreysta, Alder (—Rissoélla, 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. SKENEA, Fleming. Etymology, named after Dr. Skene, of Aberdeen, a contem- porary of Linnzeus. Synonym, Delphinoidea, Brown. Type, S. planorbis (Pl. IX., Fig. 20). Shell minute orbicular, depressed, few-whorled; peristome continuous, entire, round; operculum pauci-spiral. Animal like rissoa, foot rounded behind. Found under stones at low-water, and amongst the roots of coraillina officinalis. Distribution, ? species. Northern seas, Norway, and Britain. S. cornuella, Straits of Korea (Adams), P TRUNOATELLA, Risso. Looping-snail. Type, T. truncatula (Pl. LX., Fig. 25). (Mus., Hanley.) GASTEROPODA. 25F She muute, 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 ¢truncatelle 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, Rio, Cape, Mauritius, Philippines, Australia, Pacific. (Cuming.) ? LirHocLypPuvs, Megerle. Type, L. fuscus (Pl. 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. Fami.ty VII.—PALUDINIDA. 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. PALUDINA, Lam. River-snail. Etymology, palus (paludis), a marsh. Synonym, Viviparus, Gray. Type, P. Listeri (Pl. [X., Fig. 26). (P. vivipara, Fig. 68.) Shell tarbinated, 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 paludine are 258 MANUAL OF THE MOLLUSCA. viviparous; the shells of the young are ornamented with spiral rows of epidermal cirri. Distribution, 60 species. Rivers and lakes throughout the northern hemisphere ; Black Sea, Caspian. . Fossil, 53 species. Wealden—. Britain, &c. Sub-genus. Bithynia (Prideaux), Gray. B. tentaculata (Pl. [X., 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.) AMPULLARIA, Lam. Apple-snail, or idol-shell. Etymology, ampulla, a globular flask. Example, A. globosa (Pl. IX., Fig. 30). Synonym, Pachylabra, Sw. Shell globular, with a small spire, and a large ventricose body- whorl; peristome thickened and slightly reflected ; operculum shelly. j Animal with a long incurrent siphon, formed by the left neck- Fig. 109.* lappet; left gill developed, but much smaller than the right ;+ muzzle produced into two long tentacular processes; tentacles * Fig. 109. Ampuillaria canaliculata, Lam. (from D’Orb). South America. The branchial siphon (s) is seen projecting from the left side; 0, operculum. + The ampullaria 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 exhibit it. It would be very desirable to examine the amp. cornu-arietis, in which, probably, the gills are symmetrical, as in the cephalopods. Ss oe GASTEROPODA. 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, ampullariz are abundant, mixed w. th marine shells. Their eggs are large, enclosed in capsules, Fig. 110. Ampullaria globosa. (Wilton.) and aggregated in globular masses. The dentition of A. globosa is shown in Fig. 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., Fig. 31). Operculum horny. Shell discoidal. Asolene, D’Orbigny. A. plate. Animal without a respiratory siphon; operculum shelly. Distribution, South America. Lanistes, Montf. A. bolteniana, L. (Pl. [X., Fig. 32). Shell reversed, umbilicated, peristome thin; operculum horny. Dis- tribution, West Africa, Zanzibar, Nile. Meladomus, Sw. FPaludina olivacea, Sby. Shell reversed, imperforate ; peristone thin; operculum horny. ? AMPHIBOLA, Schumacher. Synonyms, Ampullacera, Quoy. Thallicera, Sw. Type, A. australis (Pl. [X., 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 serpule attached to them. (Cuming.) They are eaten by the New Zealanders. 260 MANUAL OF THE MOLLUSCA. VALVATA, Miiller. Valve-shell. Types, V. piscinalis (Pl. [X., Fig. 28). V. cristata (Pl. TX., Fig. 29). Shell turbinated, or discoidal, umbilicated; 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. Britain and North America. Fossil, 19 species. Wealden—. Britain, Belgium, &c. Famity VIII.—NERITIDA. 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 Fig. 111. * lip 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- binide. Teeth 7; uncini very numerous. Nerita, L. Nerite. Litymology, Nerites, a sea-snail, from nereis. Type, N. ustulata (Pl. [X., Fig. 35). * Fig. 111. Nerita polita, L. (from Quoy and Gaimard), New Irelaad. ee en ee ee GASTEROPODA. 261 Shell thick, smooth or spirally grooved; epidermis AOTEYs outer lip thickened and sometimes denticulated within; columella broad and flat, with its inner edge straight and toothed; operculum shelly, Fig. 112. Distribution, 173 species. Nearly all warm seas. “ West Indies, Red 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 paleeozoic nerites are referred by D’Orbigny to turbo, natica, &c. N. haliotis is a pileopsis. 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, Grateloup. N. radula (Pl. VIII., Fig. 9). Shell like nerita ; inner lip with a single notch in the centre. Distribution, 1 species. Pacific. Fossil, 20 species. Trias? Britain, France, &c. Velates, Montf. N. perversa, Gm. (Pl. [X., Fig. 36). Inner lip very thick and callous; outer lip prolonged behind, and par- tially enveloping the spire. PILEOLvs (Cookson), J. Sowerby. Etymology, pileolus, a little cap. Type, P. plicatus (Pl. [X., Figs. 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 Minchiahampton, 3 species, P. neritoides is a neritind. NeEritTivnA, Lam. Fresh-water nerite. Examples, N. Bee 5 (Pl. IX., Fig. 39), N. crepidularia (Pl. IX., Fig. 4 Shell rather thick at the aperture, but extensively absorbed inside; outer lip acute ; inner straight, denticulated ; operculum * Fig. 112. Operculum of NV. peloronta. West Indies. 962 MANUAL OF THE MOLLUSCA. shelly, with a flexible border; slightly toothed on its straight edge. Animal like nerita; lingual teeth ; median, minute; laterals $, 1 large, sub-triangular 2, 3 minute; uncini about 60, first very large, hooked, denticulated ; the rest equal, narrow, hooked, denticulated. The neritinee 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 UN. viridis and meleagris are found in the sea. ‘N. crepidularia has a continuous peristome, and approaches 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. Hocene—. Britain, France, &e. NAVICELLA, Lam. Etymology, naviceila, a small boat. Type, N. porcellana. Pl. IX., Fig. 41. Shell, oblong, smooth, limpet-like; with a posterior, sub- marginal apex; aperture as large as the shell, with a smal Fig. 113. Navicella. (Wilton.) columellar shelf, and elongated lateral muscular scars; oper- cultm very small, shelly. Distribution, 33 species. India, Mauritius, Ativan 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 opague, the rest slender, translucent, with denticulate hooks (Fig. 113). : | | ‘ GASTEROPODA. 263 FAMILY LX.—TURBINIDA. Shell spiral, turbinated or pyramidal, nacreous inside; oper- culum calcareous and pauci-spiral, or horny 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 (cirr7) ; 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 (alge). The shells of nearly all the turbinide are brilliantly pearly when the epidermis and outer layer of shell are removed ; many of them are used in this state for ornamental purposes. Turso, L. Top-shell. Etymology, turbo, a whipping-top. Synonyms, Batillus, Marmorostoma, Callopoma, &c.—Gray. Type, T. marmoratus. Pl. 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 7’. 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, O-pe, India, China, Australia, New Zealand, Pacific, Peru. Fossil, 360 species (including littorina) L. Silurian—. Universal. PHASIANELLA, Lam. Pheasant-shell. Synonyms, Eutropia (Humphrey), Gray. Tricolea, Risso. 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 eyen-edged; laterals 5, re ) 4 264 MANUAL OF THE MOLLUSCA. hooked, denticulated; uncini about 70, gradually diminishing 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.* IMPERATOR, Montfort. Type, I. imperialis. Pl. X., Fig. 4. Synonym, Calcar. Shell trochiform, thick, with a, flat or concave > bape whorls keeled or stellated; aperture angulated outside, brilliantly pearly ; operculum shelly. Distribution, 20 species? South Africa, India, Australia, New Zealand. TrocHus, L. Etymology, trochus, a hoop. Synonyms, Cardinalia, Tegula, and Liyona, Gray. Infundi- bulum, Montfort. Chlorostoma, Sw. Trochiscus, Sby. Monilea, Sw. Types, T. niloticus. Pl. X., Fig. 5. T. zizyphinus. Fig. 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, Fig. 115 (T. pica). Animal with 2 small or obsolete head-lobes be- tween the tentacles; neck-lappets large; sides Fig. 115. ornamented with lobes, and 3—®5 cirri; gill very cong, linear; lingual teeth 11, denticulated; uncini — 90, diminishing outwards. * Fig, 114. Trochus zizyphinus, L., Pegwell Bay, Kent. _ GASTEROPODA. 265 Distribution, 200 species. World-wide. Low water to 15 fathoms ; the smaller species range nearly to 100 fathoms. Fossil, 361 species. Devyonian—. Europe, North America, Chili. Sub-genera. Pyramis, Chemn., Tr. obeliscus. Pl. X., Fig. 6. Columella contorted, forming a slight canal. Gibbula, Leach. Tr. magus, Britain. Shell depressed, widely umbilicated ; whorls tumid. Head- lobes largely developed ; lateral cirri, 3. Enida, Adams. 3 species, Japan. Margarita, Leach. Tr. helicmus. Pl. X., Fig. 7. Shell thin ; cirri, 5 on each side. Distribution, 17 species. Greenland, Britain, Falkland Islands. Near low water, under stones and sea-weed. Llenchus, Humphrey (= Canthiridus, Montfort) E. iris. Pl. X., Fig. 8. Smooth, thin, imperforate, with a prominent base. Australia, New Zealand. /. Jris scarcely differs in form from Tr. zizyphinus; #. badius is bke a pearly phasianella; and £. varians (bankiyia, Menke) would be called a chemnitzia, if fossilised. Pl. X., Fig. 9. Alcynus, Adams. 2 species, Japan. Minolia, Adams. 1 species, Japan. Turcica, Adams. 1884. Vitrinella, C. B. Adams, 1850. Shell minute, hyaline, turbiniform, umbilicated; aperture large, orbicular. Distribution, 18 species. West Indies (5), Panama. Photinula, H. and A. Adams, 1855. Shell heliciform ; spire somewhat acute. ROTELLA, Lamarck. Etymology, diminutive of rota, a wheel. Synonym, Helicina, Gray. Type, R. vestiaria. Pl. X., Fig. 10. Shell lenticular, polished; spire depressed; base callous; lingual teeth 13; uncini numerous, sub-equal. Distribution, 15 species. India, Philippines, China, New Zealand. . Monoponta, Lam. Etymology, monos, one, and odous (odontos), a tooth. Synonyms, Labio, Oken. Clanculus. Montfort, Olivia, Risso. Types, M. labeo. Pl. X., Fig. 21. M. pharaonis. Pl. X., Fig. 12. Shell turbinated, few-whorled ; whorls spirally grooved and N 266 MANUAL OF THE MOLLUSCA. granulated ; lip thickened internally, and grooved; columella toothed, more or less prominently and irregularly ; operculum horny, many-whorled. Distribution, 18 species? West Africa, Red Sea, India, Australia. Fossil (included with trochus), Devonian—. Hifel. DELPHINULA (Roissy), Lam. Etymology, diminutive of delphinus, a dolphin. (= Cyclostoma, Gray !) Type, D. laciniata. Pl. X., Fig. 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. Red Sea, India, Philippines, China, Australia. Fossil, 30 species? Trias ?—Miocene—. Europe. Sub-genera. Liotia, Gray. L. gervillii. Pl. X., Fig. 14. Aperture pearly, with a regular, expanded border; operculum multi-spiral, calcareous. Distribution, 6 species. Cape, India, Philippines, Australia. Fossil, Hocene—. Britain, France. Collonia, Gray, 1850. CO. marginata. Pl. X., Fig. 15. Peristome simple ; operculum calcareous, with a spiral rib on the outer side. Distribution, Africa. Fossil, Eocene—. Paris. Cyclostrema, Marryat. ©. cancellata, Pl. X., Fig. 16. Shell nearly discoidal, cancellated, not pearly ; aperture round, simple ; umbilicus wide ; operculum, spiral, caicareous. Distribution, 12 species. Cape, India, Philippines, Australia, Peru. In 5—17 fathoms. Serpularia, Roemer, has the whorls smooth and disunited. Type, Huomphalus Serpula, Kon. Card. Belgium. Crossostoma, Morris and Lycett. Columella toothed when young, concealed by callus in the adult. 2 species, Great oolite. ADEORBIS, Searles Wood. Type, A. sub-carinatus. Pl. X., Fig. 17. Shell minute, not nacreous, depressed, few-whorled, deeply umbilicated ; peristome entire, nearly continuous, situated in| fi ha 4 GASTEROPODA. 267 ~ its inner side, and slightly so externally ; operculum shelly, multi-spiral. Distribution, 6 species. "West Indies—China. Low water to 60 fathoms. Fossil, 5 species. Tertiary—. Britain. EvomMPHALUS, Sowerby. Etymology, eu, wide, and omphalos, umbilicus. Synonyms, Schizostoma, Bronn. Straparollus, D’Orbigny. Ophileta, Vanuxem. Platyschisma, M‘Coy. Type, EK. pentagonalis. Pl. 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, EH. cristatus, Phil. Carb. limestone. Britain. Shell discoidal; whorls separate; outer margin sometimes foliaceous. STOMATELLA, Lam. Etymology, diminutive of stoma, the aperture. Type, S. imbricata. Pl. X., Fig. 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 2 Gena, Gray. Spire minute, marginal; no operculum. 16 species. Red Sea, India, Seychelles, Swan River, Philippines. (Adams.) Niphonia, Adams. 1 species, Japan. BRODERIPIA, Gray. Etymology, named in honour of W. J. Broderip, Esq., the distinguished conchologist. Type; B. rosea. Pl. 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.) N 2 268 MANUAL OF THE MOLLUSCA. FAMILY X.—HALIOTIDA. Shell spiral, ear-shaped or trochiform; 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 notehed or per- forated aperture. Hautotis, L. LEar-shell. Etymology, halios, marine, and ows (otos), an ear. Type, H. tuberculata, Pl. X., Fig. 21. Shell ear-shaped, with a small flat 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. tricostalis (padollus, 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 m 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, &e. Sub-genus 2? Deridobranchus, Ehrenberg, D. argus, Red Sea. Shell large and thick, like haliotis, but entirely covered by the thick, hard, plaited mantle of the animal. SromatTra (Helblin), Lamarck. Etymology, stoma, the aperture. Type, 8. phymotis, Pl. X., Fig. 22. Shell like haliotis, but without perforations, their place being occupied by a simple furrow; surface rugose, spirally ridged; my, << s- . 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. TeErnotis, H. and A. Adams, 1854. Sheli depressed, elongated, ear-shaped; spire small, and placed posteriorly; hinder part of the foot in the animal stretches far over the shell. Distribution, 2 species. East India. ScISSURELLA, D’Orbigny. Etymology, diminutive of scissus, slit. Type, 8. crispata, Pl. X., Fig. 23. Synonyms, Anatomus, Montfort ; Woodwardia, Fischer. 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 shell. 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 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) plentifiuliy alive in sea-weed on the coast of Piedmont. It has a multi-spiral operculum, like Margarita. In this species, as noticed by Mr. G. Sowerby, the s/it in the peristome of the young shell is converted into a foramen in the adult, as in the Jurassic . T'rochotoma. Distribution, 5 species. Norway, Britain, Mediterranean. In Fig. 116. Scissurella. 2. 270 MANUAL OF THE MOLLUSCA. 7 fathoms water off the Orkneys, and in deep water east of the Zetland Isles. Fossil, 4 species. Tertiary—. Britain. Sicily. PLEUROTOMARIA, Defrance Etymology, pleura, side, and tome, notch. Type, P. anglica, Pl. X., Fig. 24. Shell trochiform, sold, few-whorled, with the surface variously 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. Pleurotomariz 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 asianthina. - Sub-genera. Scalites, Conrad, IL. 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 Pleurotomaria; last whorl deflected, peristome incomplete, slightly varicose, irregular. Fossil, Devonian, Eifel. Raphistoma (angulata), Hall. lL. Silurian, United States, Canada. Shell depressed, outer lip sinuated. In R. compacta (Salter) the spire is sunk and basin-shaped, the umbilical side flat, and the last whorl a little disunited. MurcuisoniA, D’Archiac. Etymology, named in honour of Sir Roderick I. Murchison. Type, M. bilineata, Pl. X., Fig. 25. 4 Shell elongated, many-whorled ; whorls variously sculptured, and zoned like plewrotomaria ; aperture slightly channeled in front; outer lip deeply notched. The murchisonie are characteristic fossils of the paleeozoic 9 j - GASTEROPODA. 271 rocks; they have been compared to elongated pleurotomarie, or to cerithia with notched apertures; the first suggestion is most probably correct. Fossil, 50 species. L. Silurian—Permian. North America, Europe. TrRocHOTOMA, Lycett. Etymology, Trochus, and tome, a notch. Synonym, Ditremaria, D’Orbigny. Type, T. conuloides, Pl. X., Fig. 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 Rag. Britain, France, &c. ? Cirrus, Sowerby. Etymology, cirrus, a curl. Type, C. nodosus, Sby. Main. 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, France. This genus was founded on a plewrotomaria, a ewomphalus, and C. nodosus. (vy. Min. Con.) It is still doubtful what species may be referred to it. S> ~\ a Bi a a Ni J Aividiiavriar Wii ml aifdiaien 3 Fig. 117.* TANTHINA, Lam. Violet-snail. Etymology, ianthina, violet-coloured. Type, helix ianthina, L. (I. fragilis, Lam.) Pl. X., Fig. 27. Shell thin, translucent, trochiform; nucleus minute, styliform; 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- * Fig. 117. Janthina 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 ribbon, rachis unarmed ; uncini numerous, simple (like scalaria). Branchial plumes 2. Sexes separate. Distribution, 10 species. Atlantic, Coral sea. The ianthinew, or oceanic-snails, are gregarious in the open sea, where they are found in myriads, and are said to feed on the small blue acelephee (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 fully formed shells, and those near the animal were filled with eggs. They haye 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. Itis built up from glutinous matter secreted by the foot.* 2 Holopea (symmetrica), Hall. 1847. Outer lip sinuated near the base. JZ. Silurian, New York. FAmMIty XI.—FISSURELLIDA. Shell conical, limpet-shaped; apex recurved ; nucleus spiral, often disappearing in the course of growth; anterior margin notched or apex perforated; muscular impression 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.t FIsSURELLA, Lam. Key-hole limpet. Etymology, diminutive of fisswra, a slit. Type, F. Listeri, Pl. XI., Fig. 1. * Annales des Sciences Naturelles, 1865. + Fissurella is the best gasteropod for comparison with the bivalves; its large gills, placed one on each side, and its symmetrical 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. Se ee GASTEROPODA. 2738 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 ; Fig. 118, Fisswrella. (Wilton.) they chiefly inhabit the laminarian zone, but range downwards to 50 fathoms. For dentition see Fig. 118. Distribution, 1382 species. America, Britain, South Africa, India, China, Australia, Upper California, Cape Horn. Fossil, 30 species. Carb.; oolites—. Britain and France. Sub-genera. Pupillia, Gray. I. apertura, Born. (=hiantula, Lam.) Shell smooth, surrounded by a sharp white edge; per- foration very large. Distribution, South Africa. Fisswreilidea, D’Orbigny. F. hiantula, Lam. (+megatrema, D’Orbigny.). Shell cancellated; covered by the mantle of the animal. 3 species. Cape and Tasmania. (Macroschisma, Sw.) EF. macroschisma, Pl. XI., 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 the testacelle by Mr. Cuming. Distribution, Philippines and Swan River. Incapina, Gray. IF’. elegans, Gray (—=aperta, Sby.). Shell white, cancellated, margin crenulated ; covered by the reflected mantle. 3 species. California. PUNCTURELLA, Lowe. Synonyms, Cemoria, Leach. Diadora, Gray. Type, P. noachina, Pl. XI., Fig. 3. Shell conical, elevated, with the apex recurved ; perforation in front of the apex, with a raised border internally; surface cancellated. Distribution, 6 (F) species. Greenland, Boreal America, N 3 274 MANUAL OF THE MOLLUSCA. Norway, North Britain, Tierra-del-Fuego. In 20—10( fathoms water. Fossil, in the glacial formations of North Britain. RimvuLa, Defrance. Etymoiogy, diminutive of rima, a fissure. Synonym, Rimularia. Recent type, R. Blainyillii, Pl. XI., Fig. 4. Shell thin and cancellated, with a perforation near the 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—coralrag. Britain and France. EMARGINULA, Lam. Etymology, diminutive of emarginata, notched. Type, Hi. reticula, Pl. XI., Figs. 5 and 6. Shell oval, 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 scisswrella. 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 ; uncini about 60, the first large and thick, with a lobed hook, the rest linear, with serrulated hooks. (Loyén.) Distribution, 40 species. West Indies, Britain, Norway, Philippines, Australia, Range from low water to 90 fathoms. Fossil, 40 species. Trias—. Britain and France. Sub-genus. Hemitoma, Sw. Type, HK. octoradiata (EH. rugosa, Pl. XI., Figs. 7 and 8), Shell depressed, anterior margin slightly channeled. PARMOPHORUS, Blainville. Duck’s-bill limpet. Etymology, parme, a shield, and phoreus, a bearer. Type, P. australis, Pl. XI., Fig. 9. Synonym, Scutus, Montf. Shell lengthened-oblong, depressed ; apex posterior; front 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 GASTEROPODA. 275 tentacles; it is found in shallow water, and walks freely. (Cuming. ) Distribution, 15 species. New Zealand, Australia, Philippines, Singapore, Red Sea, Cape. Fossil, 3 species. Eocene?—. Paris Basin. Famity XII.—CaALyprra@ip#&. 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. Animal 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 Fig. 119, which shows dentition Th 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. Lovén places this family next to the Velutinide. 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 flat, or even concave above, and colourless. They are presumed to feed on the sea- weed growing round them, or on animalcules; a calyptrea, which Professor Forbes kept in a glass, ate a small sea slug (goniodoris) which was confined with it. Both calyptrea and puleopsis sometimes cover and hatch their spawn in front of their foot. (Alder and Clarke.) Dr. Gray arranges the bonnet-limpets next after the verme- tidee ; their lingual dentition is like velutina. 276 MANUAL OF THE MOLLUSCA. CALYPTRHA, Lam. Cup-and-saucer limpet, Etymology, calyptra, a (lady’s) cap. Synonym, Lithedaphus, Owen. Types, O. equestris, Pl. XI., Fig. 10. CO. Dillwynnii, Fig. 11. Shell conical; limpet-shaped; 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. Found 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, France, &c. Sub-genera. Crucibulum, Schum. (Dispotzea. Say., Calypeopsis, Less. ) Example, C. rudis, Pl. XI., Fig. 12. Shell spinulose; internal cup entire; attached by one of its sides. Distribution, West America, Japan, West Indies. Found on shells, with its base worn, or smoothed by a shelly deposit. (Gray.) Between this section and the next there are several intermediate forms. Trochita, Schum. (Infundibulum, J. Sby., Galerus, Humph. Trochatella and Siphopatella, Lesson.) ‘TT. radians, Pl. XI., Figs. 13, 14. (= Patella trochoides, Dillw.). T. sinensis, Pl Ay 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 Lovén; median teeth broad, hooked, denticulatcd ; uncini 3, the first hooked and serrated, 2, 3, claw-shaped, simple. CREPIDULA, Lam. Etymology, crepidula, a small sandal. 7 ———S oo GASTEROPODA. 277 Type, C. fornicata, Pl. XI., Fig. 16. Synonym, Crypta, Humph. * Shell oval, limpet-like; with a posterior, oblique, marginal apex; interior polished, with a shelly partition covering its posterior half, The crepidule resemble the fresh-water navicelle 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. PitEopsis, Lam. Bonnet-limpet. Etymology, pileos, a cap, and opsis, like. Synonyms, Capulus, Montf. Brocchia, Bronn. Type, P. hungaricus, Pl. XI., Fig. 17, P, militaris, Pl. XT., Fig. 18. Shell conical; apex posterior, spirally recurved; aperture rounded ; muscular impression horse-shoe shaped. Animal with a fringed mantle-margin; lingual teeth like calyptreea. P. 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. militaris is extremely like a velutina. Distribution, 8 species. West Indies, Norway, Britain, Mediterranean, India, Australia, California. Fossil, 20 species. Lias—. Europe. Sub-genus. Amathina, Gray. A. tricarinata, Pl. XT., Fig. 19. Shell depressed, oblong; apex posterior, not spiral, with three strong ribs diverging from it to the anterior margin. Platyceras, Conrad (acroculia, Phil.). P. vetustus. Carb., limestone. Britain. Fossii, 20 species. Devonian—Trias. America, Europe. Metoptoma, Phillips. M. Pileus, Ph. Shell limpet-like, side beneath the apex truncated, resembling the posterior yalye of a chiton. 7 species. Carb. limestone. Britain. 278 MANUAL OF THE MOLLUSCA. Hipponyx, Defrance. Etymology, hippos, a horse, and onyx, a hoof. Type, H. cornucopia, Pl. XI., Figs. 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, Philiy - pines, Australia, Pacific, West America. Fossil, 10 sp. U.chalk—. Britain, France, North America. Sub-genus. -Amailthea, 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 turbinella of the Eastern seas. | Famity XIII.—Patrettipm. 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. Respiratory organ in the form of one or two branchial plumes, lodged in a cervical cavity; or of a series of lamelle 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 cyclo-branchiata of: Cuvier included the chitons and the limpets, and was characterised by the circular arrangement of the branchiz. At a comparatively recent period it was ascer- tained that some of the patellae (acmewa) had a free, cervical gill; whilst the chitons exhibited too many peculiarities to admit of being associated so closely with them. Professor Forbes 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 (nacelle) does not form a complete circle, but ends without passing in front of the animal’s head. : PATELLA, L. Rock limpet. Etymology, patella, a dish. Synonyms, Helcion Montfort ; Cymba, Adams. ee | & GASTEROPODA. 279 Example, P. longicostata. Pl. XI., Fig. 22. Shell oval, with a sub-central apex; surface smooth, or ornamented with radiating striz or ribs; margin eyen or spiny ; interior smooth. Animal with a continuous series of bran- chial lamelle; 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. Fig. 120 shows the teeth, but not the uncini of P. vulgata. The Cape limpets (e.g. P. denticulata) have a minute central tooth, which is wanting in any other species hitherto examined. (Wilton.) The dental canal of the common British limpet (P. vulgata) is rather longer than its shell; it bas 160 rows of teeth, with 12 teeth in each row, or 1,920 in all. (Forbes.) 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 Thanet, they live in pits half 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 nullipores, 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. (Dr. Johnston.). In the north of Ireland they are used for human food, especially in seasons of scarcity ; Fig. 120. Patella vu'gata. (Original, Wilton.) * 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 they leave are very peculiar, and not likely to be mistaken when once seen. 280 ; MANUAL OF THE MOLLUSCA. many tons weight are collected annually near the town of Larne alone. (R. Patterson.) On the western coast of South America there is a limpet which attains the diameter of a foot, and is used by the natives asa 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 strize not parallel like those produced by their teeth on nidllipore. 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 group of oysters (0. cornucopic), with a colony of the Hipponyx mitruia 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 Calyptreide generally, although furnished wita lingual teeth (Fig. 96) like those of the animal-feeding Velutina, and themselves manifesting carnivorous propensities (p. 275), 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 Nuacelia pellucida is found on the fronds of the tangle, and assumes the form called WV. levis, when in lives on their stalks. (Forbes.) The Acmea testudinalis becomes laterally compressed and is called A. alvea when it grows on the blades of the Zostera (Gould) ; and Patella miniata of the Cape becomes a new “‘ genus” (Cymba, Adams, not Broderip) when it roosts on the round stems of sea-weed, and takes the form called P. compressa. (Gray.) Distribution, 144 species. Britain, Norway, &c. Wellington Channel. World-wide. Fossil, above 100 species of patellide, including acmea, L. Silurian—. North America, Europe. Sub-genera. Nacedla, Schum. (= patina, Leach). Exumple, P. pellucida. Pl. XI., Fig. 23. Shell thin; apex nearly marginal. Animal with the mouth entire below. Branchiz not con- * A similar circwmstance has been noticed in the fresh-water Paluding and Am- pullaria, by Dr. Bland and Mr, R. Swift; in the absence of other food they devour the green vegetable matter incrusting one another’s shells, and in doing this remove the epidermis, or even make holes in the shell. GASTEROPODA. 281 tinued in front of the head. Found on the fronds and stalks of sea-weeds. Britain, Cape, Cape Horn. Scutellina, Gray. §.crenulata. Shell with a broad margin internally. 7 species. Red Sea, Philippines, Pacific, Panama. (Cuming. ) AcmmA, Eschscholtz. Etymology, acme, a Synonyms, Tectura, M. Edw. Lottia and Scurria, Gray. Patelloida, Quoy. Type, A. testudinalis. Pl. XI., Fig. 24. Shell like patella. Animal with a single pectinated gill; lodged in a cervical cavity, 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. Lepeta, Gray (= pro-pilidium, Forbes). Patella czeca, Miiller. Shell minute, apex posterior. Animal blind.. Britain. 30—90 fathoms. Pilidium, Forbes. P, fulva, Miller. Britain. 20—80 fathoms water. Shell 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. Pl. XI., 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, Red Sea, = Peru. Fossil, 1 species. Sicily. SIPpHONARIA, Sowerby. Type, 8S. sipho. Pl. XI., Fig. 25. Shell like patella; apex sub-central, posterior; muscular impression horse-shoe shaped, divided on the right side by a 282 MANUAL OF THE MOLLUSCA. deep siphonal groove, which produces a slight projection on the margin. Animal with a broad head, destitute of tentacles; eyes sessile on prominent rounded lobes; gill? single. The siphonariz are found between tide-marks, like hmpets; Dr. Gray places them with the pulmonifera, between the auriculidz and cyclos- tomidee. Distribution, 41 species. Cape, India, Philippines, Australia, New Zealand, Pacitic, Gallapagos, Peru, Cape Horn. (Cuming.) — Fossil, 3 species. Miocene—. France. FAMILY XIV.—DENTALIADA. Tooth-shells. DENTALIUM, L. Type, D. elephantinum. Pl. XI., 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 0; oral orifice fringed ; foot pointed, conical, with symmetrical side-lobes, and an _ attenuated base, in which is a hollow communicating with the stomach. Branchiz 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. Famity XV.—CHITONIDA. CuiTon, L. Etymology, chiton, a coat of mail. Examples, C. squamosus, spinosus, fascicularis, fasciatus. Pl. XI., Figs. 28—31. * D. gadus of Montagu is an annelid, belonging to the genus ditrupa. GASTEROPODA. 283 Shell composed of eight transverse imbricating plates, lodged in a coriaceous mantle, which 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 eyes or tentacles. - Branchie forming a series of lamellz 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 symmetrically 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—2é 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 Chiloé. Fossil, 37 species. Silurian—. Britain, Belgium, &c. Sub-genera.* Chiton. Synonyms, Lophurus, Poli. Radsia, Callo-chiton, Ischno-chiton, and Lepto-chiton. (Gray.) Example, C. squamosus. Pl. XI., Fig. 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, Valparaiso. Acanthopleura, Guilding. C. spinosus. Pl. XI., 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 Zcological Society. Dr. Middendorf employs the number of the branchial lamine for distinguishing the sections. 284 MANUAL OF THE MOLLUSCA. Synonyms, Schizo-chiton, Corephium, Plaxiphora, Onycho- chiton, Enoplo-chiton, Gray. Distribution, West Indies, Cape Horn, Falklands, Africa, Philippines, Australia, New Zealand, Valparaiso. Mopalia, Gray. ©. Hindsii. Border hairy. Distribution, West America, Falkland Islands. Katharina, Gray. C. tunicatus. Mantle covering all but the centre of the plates. Distribution, New Zealand, West America. Oryptochiton, Gray, ‘‘Saw-dust chiton.” ©. amiculatus. Valves covered with scaly epidermis. Synonyms, Cryptoconchus, Sw. -Amicula, Gray. Distribution, California. New Zealand. Acanthochites, Leach. C. fascicularis. Pl. XI.. Fig. 30. Border ornamented with tufts of slender spines, opposite the plates. o Distribution, Britain, Mediterranean, New Zealand. Chitonellus, Lam. C. fasciatus, Quoy. Pl. XI., Fig. 31. Border velvety ; exposed portion of the plates small, distant; apophyses close together. The dentition of chitonellus is repre- sented in Fig. 121. Distribution, 10 species. West Indies, West Africa, Philip- pines, Australia, Pacific, Panama. ‘The chitonelle are found in fissures of coral rock. (Cuming.) Fossil, Carb. Scotland. Gryphochiton, Gray. C. neryicanus. Helminthochiton, Salter, 1847. H. Griffithii, Salter, Geological any A \/ / FR NS | O tae ie Fig. 121. Chitonellus. Tasmania. (Wilton.) Journal. Plates sub-quadrate, not covered by the mantle: apophyses widely separated. Fossil, Silurian. Ireland. Brownia, Candei, D’Orbigny, 18538. A minute discoidal shell, associated with Helicophiegma 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 4 GASTEROPODA. 285 lines. South Seas (= Echinospira, Krohn and Jasonilla- Maed). Recluzia, Petit, 1853. R. Jehennei, Red Sea. R. Rollandiana, Atlantic, and Mazatlan. Animal pelagic, resembling ianthina; one inch long. Shell paludiniform, thin, with a brown epidermis; whorls ventricose; aperture ovate-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 Atlantidze, are, for the most part, composed of prosobranchiate larvee ; but the genera to which they belong has not yet been ascertained. ORDER II.—PULMONIFERA. 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-operculate, and sometimes shell-less. The pulmonifera are closely related to the plant-eating sea- snails (holostomata), through Cyclostoma, and to the nudibranchs by Oncidiwm. 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. Secrion A.—IN-OPERCULATA. The typical pulmonifera vary much in appearance and habits, but agree essentially in structure. Most of them have suffi- 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 MANUAL OF THE MOLLUSCA. aquatic tribes. Jand-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. Fresh-water snails (Limneide) 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‘obyious characters afforded 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 similar in shape ; curves indicate gradual scandal and angles accompany sudden altera- tions of form. U see Rie ehisieivistptulutel ol OTST Tt Ole ll vivivivivivivivivl vivivivielvlulylv|lulvl Fi — He) (tel kal c th of Achkatina. The absolute number of teeth is only a specific character, and is usually greatest in the larger species; but the Helicedle have fewer teeth in proportion than the Helices, and Velletia has * Fragment of the lingual membrane of Achatina fulica, with central and lateral teeth more enlarged, from a specimen communicated by J. W. Laidlay, Esq. ae at fie eS rr GASTEROPODA. 287 fewer than Ancylus. The anomalous genus Amphibola (p. 139) is said to haye 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 ina 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 Limnea or Planorbis ina glass of water, inside which the green conferva has begun to grow; they will be observed incessantly cleaning off this film. The upper lip withits 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 Limnea 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 Van Beneden and Windischmann,+ by Oscar Schmidt,t and by Gegenbaur ;§ the memoir by the last-named author, contains full information respecting Limawx 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 velwm of marine gasteropods—which in Doris, Polycera, and 4olis, has been seen to exhibit similar contractions. (Gegen- baur.) To this contractile vesicle the name of Yelk-sac was given by Van 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+ Recherches sur l’embryogenie des Limaces. Miiller’s Archiv. 1841. } Ueber die Entwickelung von Limaz agrestis. Miiller’s Archiv. 1851. § Beitriige zur Entwickelungsgeschichte der Land-gasteropoden. Siebold anil KGiliker’s Zeitschrift, 1852. 288 MANUAL OF THE MOLLUSCA. tached to the parietes of the ‘ vitellary’ vesicle, which Gegenbaur and Schmidt compare to a Wolffian body. ‘‘Gegenbaur draws attention to the fret, that the first rudi- ment of the shell in Zimaw, 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. ) FAamMILy I.—HEwIcripz%.* Land-snails. Shell external, usually well developed, and capable of con- taining the entire animal; aperture closed by an epiphrag:n during hybernation. + 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. Hettix, L.t 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 aaa in straight rows, edge-teeth dentated. * The account of this family is chiefly taken from Dr, L. Pfeiffer’s Monographia Heliceorum. + The epiphragm is a layer of hardened mucus, sometimes strengthened with car. bonate of lime ; it is always minutely perforated opposite the respiratory orifice. ¢ The synonomy of the genus would fill several pages. See p. 48, GASTEROPODA. 289 Distribution, including the sub-genera, above 1,600 species (several hundred species are undescribed). 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 observed 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. hzeemastoma, fret... Wig. *t. Geotrochus (lonchostoma) Hasselt, Trochiform, flat beneath. Polygyra, Say. Depressed, many-whorled. H. polygyrata, Pl. XIL., Fig. 2. Tredopsis, Raf. Aperture contracted by tooth-like projections. H. Hirsuta, Pl. XIT., Fig. 5. Carocolla, Lam. Peristome continuous. H. lapicida, Pl. XII., Tie. 3. Sub-genera. Anastoma, Fischer. (Tomigerus, Spix.) 4H. zlobulosa, Pl. XII., Fig. 4. Aperture of adult turned up- wards, ringent; 4 species. Brazi.. Hypostoma (Boysii), Albers, is a minute Indian snail, in which the aperture is similarly distorted. Lychnus (Matheroni, Req.) has a similar shell, but no apertural teeth ; 3 species occur in the Eocene Tertiary of South France. Streptaxis, Gray. H.contusa, Pl. XII., Fig. 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. XII., Fig. 7. Imperforate, globosely conoid, close-whorled, aperture lamellate within, lip- sharp; 3 species. Jamaica. Prosérpina (nitida), Guilding. Shell depressed, shining, callous beneath ; aperture toothed inside; peristome sharp. Distribution, 6 species. Jamaica, Cuba, Mexico. Fossil, Eocene—. Isle of Wight. (F. Edwards.) Helicella, Lam.* Type, H. cellaria, Pl. XII., Fig. 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 original); by Montfort to Helix Algira; in his later works he adopts Z/elicella. 0 290 MANUAL OF THE MOLLUSCA. Synonyms, Nanina (citrina), Gray; Ariophanta (leevipes, Pl. XII., Fig. 9), Desm. Shell thin, polished ; peristome thin, not reflected. Animal with the tail truncated and glandular, like Arion ; mantle-margin produced, partly covering the shell. Distribution, 295 species. South Asia and Islands, New Zea- land, Pacific Islands, West Indies. Tanystoma (tubiferum), 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. ViTRINA, Draparnaud. Glass-snail Type, V. Draparnaldi, Pl. XII., Fig. 28. Synonym, Helicolimax, Fer. 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 sheil; 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 witha single long, recurved apex. (Thomson.) Occasionally animal-feeders, like the slugs. ° V. Cuvieri and Freycineti (Helicarion, Fer.), tail longer, more abruptly truncated, with a caudal gland like arion, mantle more developed. Distribution, 87 species. Most abundant in north part of the Old World. Sub-genera. Duudebardia, Hartm. (Helicophanta, Fér.) VY. brevipes, Pl. XII., Fig. 29. Shell perforated, horizontally involute; aperture oblique, ample. 8 species. Central Europe. Simpulopsis (sulculosa), Beck. Shell succinea-shaped. 4 species. Brazil. — SuccinEA, Draparnaud, Amber-snail. Type, S. putris,-Pl. XIT., Fig. 23. Synonyms, Oochlohydra, Fér.; Helisiga (S. Helens), Less. ; Amphibulima (patula), Beck ; Pelta (Cumingii), Beck. Shell imperforate, thin, ovate or oblong ; spire small; aperture large, obliquely ovak; columella and peristome simple, acute. _ Animal large, tentacles short and thick, foot broad; lingual GASTEROPODA. 291 teeth 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, 7 species. Eocene. Britain. Sub-genus. Omalonyx, D’Orbigny. O. unguis, Pl. XIL., 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. BuuLimus, Scopoli. Etymology? Boulimos, extreme hunger (in allusion to its voracity !). Synonym, Bulinus, Brod. (not Adans). Type, B. oblongus, Pl. 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. JS. ovatus attains a length of six inches, and is sold in the market of Rio; it oviposits amongst dead leaves, the eggs have a brittle shell, and the young when hatched are an inch long. (See p. 44, fa Pe Fig. 31.) Sot CON Sections. Odontostomus (gargantuus), AaaR SE ean Beck, aperture toothed. 13 species. § fij/!':"\ 33 Brazil. UE iy i Pachyotis, Beck (Caprella, Guild.), [2/3 ) Fig. 123.* fous Partula, Fér. PP. faba, Pl. XII., WW Fig. 13, Tahiti. 26 species. Asiatic, Australian, and Pacific Islands, South America. The animal is ovoviviparous. Gibbus (Lyonnetianus) Montf.: Shelé hump-backed. Mauritius, 2 _ species. Fig. 12%. Bulimulus, Leach. B. decollatus, Pl. XII., Figs. 11 and 12. Shell small, ip acute. Above 300 species. England, 3 species. * Fig. 123. Bulimus auris-vu'pina, Chemn. The great extinct Jand-snail of St. _ Helena; from a specimen pr. sented by Chas. Darwin, Esq. See “ Journal of a Voyage rcuuil the World.” 02 £92 MANUAL OF THE MOLTUSCA. Zua, Leach. Z. lubrica, Pl. XII., Fig. 14 Shell polished, columella slightly truncated. 6 species. Azeca, Leach. A. tridens, Pl. XII., Fig. 15. Shell polished, peristome thickened and toothed. 4 lying species. Distribution, 1,120 species. Universally distributed. Fossil, 30 species. Hocene—. Europe, St. Helena, Austraiia, West Indies. B. Guadalupensis occurs in modern limestone, with human remains. AcHATINA, Lamarck. Agate-shell. Type, A. variegata, Pl. XII., Fig. 22. Synonyms, Cochlitoma, Fér. Columna, Perry. Subulina (octona), Beck. lLiguus (virgineus), 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 Achatine 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. Distribution, 370 species. Europe, Africa, Asia, and tropical America, Fossil, 19 species. ocene—. Europe and St. Helena. Sub-genera. Glandina (voluta), Schum. (Oleacina, Bolten ; Polyphemus, Montf.) Shell oblong, fusiform ; 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. F'requentslow and moist situations ; in confinement one refused vegetable food, but ate another - snail. (Say.) 186 species. West Indies, Central America, Mexico, Florida. Fossil. Kocene—. Glandina costellata. Isle of Wight. (F. Edwards.) Achatinella (vulpina), Sw. (Helicteres, Fér.) Columella twisted into a strong, tooth-like fold. Sandwich Islands 25, Mariannes 2, Ceylon 1. Pupa, Lamarck. Chrysalis-shell. Type, P. uva. Pl. XII., Fig. 16. BA Synonym, Torquilla (juniperi), Studer. Tare | i 4 ‘ GASTEROPODA. 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. Distribution, 236 species. Greenland, Europe, Africa, India, Pacific Islands, North and South America. Fossil, 40 species. Carb. America. (Dawson.) Eocene—. Europe. Sub-genus. Vertigo, Mill. V. Venetzu, Pl. XII., Fig. 17. Shell minute, sometimes sinistral. Animal with the oral tentacles rudimentary or obsolete. 12 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, UYLINDRELLA, L. Pfeiffer. Cylinder-snail. Type, C. cylindrus, Pl. XII., Fig. 20.+ 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. BAL&A, Prideaux Type, B. perversa. Pl. XII., Fig. 21. Synonym, Fusulus, Fitz. * 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. + The figure is taken from a specimen in Mr. Cuming’s cabinet, in which the empty apex, usually decollated, remains attached to the adult shell. 294 - MANUAL OF THE MOIMLUSCA. 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 1,668 feet. (Wollaston.) Fossil, 1 species. Hocene. Sub-genus. Megaspira (elatior), Lea, Pl. XII., Fig. 18. Shell dextral, with the columella transversely plaited. Distribution, 1 species. Brazil. Fossil, 1 species. Eocene—. Rheims. TORNATELLINA, 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. Paxinuus, 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. CrLAusILiA, Draparnaud. Etymology, Diminutive of clawswm, a closed place, Synonym, Cochlodina, Fér. | Example, C. plicatula, Draparnaud (=C. Rolphii, Leach), WE ll. Fig. 19. Shell fusiform, sinistral; aperture elliptical or pyriform, con~ tracted by lamella, and closed when adult by a movable shelly plate (clausiwm) in the neck, Animal with a short, obtuse foot ; upper tentacles short, lower — very small. C. bidens has 120 rows of 50 teeth; C. migricans 90 rows of 40 teeth each. Distribution, 386 species. Europe, Asia, Africa, and South America. GASTEROPODA. 995 Fossil, 20 species. Eocene—. Britain and France. Coal- strata, Nova Scotia. (Lyell.) C. maxima, Grat., Miocene, Dax, is two inches in length. Famizy IJ.—Limacipz. 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. Limazx Sowerbii, Fér. Brit. Limax, L. Slug. Type Li. maximus. Pl. XII., Fig. 25. (L. cinereus, Miller.) 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 striz ; 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 mantie, 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 themselvesin drought and frost. Limax noctilucus, Fér. (Phosphorax, Webb), found in Teneriffe, has a luminous pore in the posterior border of the mantle. 296 MANUAL OF THE MOLLUSCA. Distribution, 51 species. Europe, Canaries, Sandwich Islands, Australia. Fossil, Kocene—. Britain. The Ancylus? latus, Edw., of the Isle of Wight, appears to be a Limax. Sub-genus. Geomalacus (maculosus) Allman. Treland. Shell unguiform. Animal with a mucus-gland at the extremity of the tail; respiratory orifice near the right anterior border of the mantle. ANADENUS, Heynemann, 1863. Shell round, calcareous, nucleus posterior; mantle large and rough; respiratory orifice on the right side and near the middle of the mantle; generative orifice distant from it behind the right tentacle. Dorsal surface not ridgel; tail without a mucus-gland, and pointed. Distribution, 2 species. Himalayas. INCILARIA, 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 14 inches. 6 species. North America, China. Philomycus (Raf.) Fér. — Tebennophorus, Binney, 1842, Boston Society’s Journal (Helix Carolinensis, Bosc) is also a slug with a long mantle. ARIoN, Férussac. Land-sole. Type, A. empiricorum, Fér. 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 limaw ; 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 yery phos- phorescent for the first fifteen days. (Bouchard.) GASTEROPODA. 997 Distribution, 20 species. Europe. Norway, Britain, Spain, South Africa. Fossil. Newer Pliocene, Maidstone. (Morris.) Plectrophorus (corninus, Bosc) Fér. 4 species. Teneriffe ; represented as having a small conical shell on the tail ; probably an erroneous observation. PARMACELLA, Cuvier. Type, P. Olivieri, Cuvier. Etymology, parma, a small shield. Synonym ? Peltella (Americana), Van Beneden. Shell concealed, oblong, nearly flat, apex sub-spiral. Animal vitrina-like, with an ample foet, poimted behind, and furnished with a mucus-pore; mantle small, shield-like in the middle of the back, partly or entirely concealing the shell. P. calyculata, Sby. (Cryptella, Webb), Pl. XID, Fig. 27, is patelliform, with an exposed papillary spire. Distribution, 7 species. South Europe, Canary Islands, North India. JANELLA, Gray, 1850 (not Grat. 1826). Synonym, Athoracophorus (!), Gould. Type, Limax bitentaculatus, Quoy. Elongate, limaciform, covered bya 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. ANEITEA, Gray, 1860. Mantle small and triangular, tooth strap with a single median tooth. Distribution, 1 3 aes A. Macdonaldu. New Hebrides, New Caledonia, PARMARION, Fischer. 1855. Shell 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. TRIBONIOPHORUS, Humbert, 1863. Mantle small, triangular, back with an almost imperceptible furzow ; teeth with wavy edges. Distribution, 3 species. New South Wales. 03 238 MANUAL OF THE MOLLUSCA. VIQUESNELIA, Deshayes, 1887. ' Shell internal, rudimentary, oval, suborbicular, siightly con~ — cave below, and thickened at the edges; summit sub-central. Pf Fig. 125. Testacella haliotoides, Fer.* TESTACELLA, Cuvier. Shell small, ear-shaped; situated on the posterior extremity of the body. . Animal, slug-like, elongated and tapering towards the head ; back with two principal lateral furrows, 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. ~ RAL 4 tf yg GY Fe SENSI "WB SS a OOF SSS SN Ny \ ff’ Vi SS Qa ik ‘f if, Sek, Ny if oP We Sa SSG, HH, if Wie SS i clot Fig. 126.t During winter and dry weather the Testacella forms a sort yeas of cocoon in the ground by the exudation of its mucus. If this cell is broken, the 3 =i, animal may be seen completely shrouded — ee sex, in its thin opaque white mantle, which . es rapidly contracts until it extends but a little way beyond the margin of the shell. | Fig, 127 represents 7. 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 Norwichs + Part of the lingual membrane of 7. haliotoides, from a preparation by Fisher — Cocken, Esq., of Botesdale. The dentition resembles that of lanthina. Fig. 127. Testacella. GASTEROPODA. 299 found by Mr. Cunnington, in fields near Devizes), just dis- turbed from its sleep; s, the shell; m, the contracted mantle. Distribution, 8 species. South Europe, Canary Islands, Britain (introduced). Fossil, 2 species. Tertiary. Faminy ITI.—OncIDIADZ. Animal, slug-like, destitute of any shell, completely covered by a coriaceous mantle; tentacles cylindrical, retractile, with eyes at their extremeties ; foot much narrower than the mantle. Oncrpium, Buchanan. Type, O. Typhee, 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 yeil; no horny jaws; tongue broad, with above 70 rows of lingual teeth (in O. celticwm), teeth 54.1.54;* the central teeth minute, triangular, with a single obtuse spine; laterals shghtly curved; heart opistho-branchiate; respiratory orifice posterior, distinct from the vent; sexes combined, ¢ organ under the right tentacle, 9 at the posterior extremity of the body. Distribution, 16 species. Britain, Mediterranean, Red 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 haye been separated under the name Peronia, Bl. (Onchis, Fér). One species (0. celticwm) 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.) ; ? Buchanania (oncidioides), Lesson. Named after Dr. F. - Hamilton (Buchanan), the zoologist of India. Animal oval, entirely covered by asimple mantle ; respiratory orifice in the centre of the back; head with 4 tentacles, retracti‘e ; oy * This is a convenient mode of stating the number of lin ual teeth in each row; it means that there is a single (symmetrical) tooth in the centre, and 54 lateral (un- symmetrical) 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—Peronia Mauritiana, 823,80 300 MANUAL OF THE MOLLUSCA. beneath the mantle; foot oval. much smaller than the mantle; | length 34 inches. Coast of Chili. (Requires confirmation.) VAGINULUS, Férussac. Type, V. Taunaisu, Férussac. Synonym, Veronicella, 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, 9 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. Famity LVY.—LIMNzAIDA. Shell thin, horn-coloured; capable of containing the whole animal when retracted ; aperture simple, ip 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 Limneids 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 xstivate in the mud. The fresh-water snails (and also Neritina) can lower them- selves from aquatic plants by a mucous thread, and re-ascend by the same ; a Physacan be lifted out of the water by its thread. LimnzA,* Lamarck. Pond-snail. Hiymology, Limnaios, marshy. Type, L. stagnalis, Fig. 128. Pl. XII., 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 (ZL. 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 termiaation. cng GASTEROPODA 301 I, peregra feeds on the green fresh-water algae; L. stagnalis prefers animal substances. Fig. 128, L, stagnalis. Distribution, 90 species. Europe, Madeira, India, China, North America. Fossil, 70 species. Wealden—. Britain, France. Sub-genus. Amphipeplea, Nilsson. A glutinosa, Pl. XII., Fig. 31. Shell globular, hyaline. Animal with a lobed mantle, capable of expansion over the shell, 4 species. KEurope; Philippines Fig. 129. C. pulchra. CHILINIA, Gray. Chilian-snail. Example, C. pulchra, D’Orbigny, Fig. 129 Synonym, Dombeya, D’Orbigny. Shell oval, thin, ornamented with dark spots or wavy bands; columella thickened, with one or two strong prominent folds. Distribution, 18 species. South America; in clear running streams. Fossil, 1 species. Miocene, Rio Negro, Patagonia. (D’Orb.) Puysa, Draparnaud. Type, P. fontinalis, Pl. XII., Fig. 32. Etymology, Physa, a pouch. | Synonyms, Bulin, Adans. Rivicola, Fitz, Isidora, Ehr. 202 MANUAL OF THE MOLLUSCA. Shell ovate, sinistrally 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. Physopsis, Krauss, South Africa, has the base of the columella truncated. Camptoceras (terebras), Benson, India, has the whorls dis- united, and the peristome continuous. Distribution, 20 species. North America, Europe, South Africa, India, Philippines. Fossil, 43 species. Wealden—. Britain, France. The largest living species (P. Maugere, Ecuador ?) is 15 lines in length. A fossil species found at Grignon measures 26 lines, and another equally large occurs in India. Ancy us, Geoffroy. River-limpet. Etymology, Ancylus (agkulos) a small round shield. Type, A. fluviatilis, Miller. Pl. XII, Fig. 33 (Patella lacustris, L.). Shell conical, limpet-shaped, thin; apex posterior, sinistral ; interior with a sub-spiral muscular scar. Animal like Limneea; tentacles triangular, with eyes at their bases ; lingual teeth 37.1.37, in 120 rows, centrals small, laterals with long recurved hooks. | Distribution, 49 species. North and South America, Europe Madeira. On stones and aquatic plants in running streams, Fossil, 8 species. Hocene, Belgium. Sub-genera. Velletia (oblonga, Lightfoot), Gray. (Acroloxus, Beck.) Shell and Animal dextral; lingual teeth 40, in 75 rows. 3 species. West Indies, Hurope. 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. New Zealand. PLANORBIS, Miiller. Synonym, ‘‘ Coret,”” Adans. Type, P. corneus, Pl. XII., Fig. 34. Shell discoidal, dextral, many-whorled; aperture crescentic, peristome thin, incomplete, upper margin projecting. Animal with a short, round foot; head short, tentacles . | ; GASTEROPODA. 303 slender, the eyes at their inner bases; lingual teeth sub- quadrate, central and marginal bicuspid, laterals tricuspid ; excretory orifices on left side of the neck. Some species of Planorbis have the suturesandspire 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. 182. has 5 teeth in the aperture which nearly close the passage. Distribution, 145 species. North America, Europe, India, China, Fossil, 69 species. Wealden—. Britain, France. Gundlachia, ancyliformis, Pfeiffer, 1850. Fresh waters. Cuba. Shell thin, obliquely conic; apex inclined posteriorly; base closed for two-thirds by a flat, horizontal plate; aperture semi- circular. FAMILY V.—AURICULIDA. Shell 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, eylin- 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 (Lovén); another species examined by Mr. Wilton has 11 large laterals and about 100 smaller (wncini) on each side, gradually diminishing towards the edge (Fig. 131): ¢, central teeth; /, laterals. PIP p, ASAT Wien ? * t Suc vies 4 wet MAS } \ \ wy AI7% SSAA | Yrs i“ PAP SSM Me We SNR atitten FAQS ws u e » e u P Fig. 131. The Awricule 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, communicated by J. S. Gaskoin, Esq. 804 MANUAL OF THE MOLLUSCA. AURICULA, Lamarck. Type, A. Jude. Pl. XII., Fig. 35. Etymology, Auricula, a little ear. Synonyms, Oassidula, Fér. (not Lam.). Marinula (pepita) King. Geoyula, 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. ?P Neocomian—. France. Fig. 132. A. auris-felis. (From Eyd. and Soul.) A. Jude 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. Sub-genera, Polydonta, Fischer, P. scarabeeus, Pl. XII., Fig. 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. Inhabits moist spots in woods near the sea, and is wholly terrestrial, feeding on decayed vegetables. (Adams.) 1 Tertiary species. Pedipes (afra), Adans. Shell ovate, spirally striated, aperture denticulated on both sides; the animal loops in walking, like truncatella. Distribution, West Indies, Africa, Philippines, Pacific Islands. Under stones on the sea-shore. Fossil, 5 species. Hocene—. Britain, France. Conovuuus, Lamarck. Type, O. coniformis, Brug. Pl. XII., Fig. 37. (= Voluta coffea, L. ?) i Synonyms, Melampus, Montfort. Rhodostoma, Sw. GASTEROPODA. 3805 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 laits. . Animal with short, tapering, and rather compressed tentacles ; foot divided transversely into two portions, advanced successively in walking. Distribution, 56 species. West Indies, Europe. Im salt- marshes and on the sea-shore. The British species have thin ovate shells, with the spire moderately produced, and the aper- ture oval. They form the sub-genus Alexia (denticulata), Leach. Fossil, Eocene. Britain, France. CAkYCHIUM, Miiller. Type, C. minimum, Pl. XII., Fig. 39. Synonym, Auricella, Hartm. Shell minute, oblong, finely striated transversery ; 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. ay e 2h, } ot 4 DD CE : "gO IDM RR eee "noapnsmyanynyy ose e Fig. 133.* SEecTIoN B.—OPERCULATA.f+ The Operculated land-snails are exceedingly like periwinkles * Siphonaria species from the Cape ; three rows of teeth, c central, 7 laterals, from a preparation by J. W. Wilton. Esq., of Gloucester. : + Phanera-pneumona (open-lunged), Gray. The account of this group is chiefiy taken from the catalogue prepared by my friend Dr. Baird. 3806 MANUAL OF THE MOLLUSCA. (littorine), and chiefly differ from them in the 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 cavity is situated on the back of the neck, and quite open in front. Lingual ribbon narrow; teeth 7-ranked. Fig. 134. Lingual teeth of Cyclophorus.t 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 Helicide. The oldest fossil species — are found in the Kocene Tertiary. : FAmMILy VI.—CycLosToMID&. Shell spiral, rarely much elongated, often ‘depressed, spirally. striated; aperture nearly circular; peristome simple. Oper- | culum distinctly spiral. q Animal with the eyes on slight prominences at the outer bases of the tentacles; tentacles contractile only ; foot rather elongated. i] CycLosTomMA, Lamarck. Etymology, Cyclos, circle, stoma, mouth. Type, O. elegans, Pl. XII., Fig. 40. Synonym, Leonia (mammillaris) and Lithidion, Gray. Shell turbinated, thin, axis perforated: aperture oval; peristome continuous, simple, straight or expanded; epidermi very thin. Operculum shelly, pauci-spiral. * The tentacles of the felicide are retractile by inversion (p. 18), those of th cyclostomide are contractile only. + C. aquilum, Sby. (original). From a specimen gathered by J. W. Laidlay, Esq,, on the steps of the great idol-temple of Moulmein, Birmah. ‘ GASTEROPODA. 3C7 Animal with clavate tentacles; sole of the foot divided by a longitudinal groove, the side moved, alternately in walking; the end of the long muzzle is also frequently applied, as by the looping-snails (Truncatellze), and used to assist in climbing. Fig, 135. Cyclostoma 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 T'ropidophora by Troschel. They are found in Madagascar and the adjacent islands and coast of Africa. Fossil, 40 species. Eocene, Europe. Sub-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. Choanopoma, 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, 70 species. West Indies, and a few in Tropical America. Cistula (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., differs in the operculum being “ sub-cartilaginous.” Distribution, about 70 species. West Indies; Tropical America, 8 species. Realia, hieroglyphica, Gray. = Hydroczena (part) Parreyss, Omphalotropis, Pfr. Liarea (Egea), Gray. Bourciera, helicine- 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 MOLLUSCA. camerated within. Distribution, 18 species. South Europe; Corfu, India. Adamsiella (mirabilis) Pfeiffer, 1851 = Choanopoma, Pfr. (part) 1847. ‘‘ Operculum thin, rather cartilaginous.” Distribu- tion, 12 species. Jamaica, Demerara. Named after the late Professor C. B. Adams, of Amherst, Massachusetts. Cyclotopsis, Blanford. Asia. ? Ferussina, Grateloup. Etymology, named in honour of Baron Ferussac. Type, F. anastomeeformis, Gr. Synonym, Strophostoma, Desh. Shell rounded, depressed, umbilicated ; whorls transversely striated above, spirally keeled below ; aperture turned obliquely upwards, peristome simple. Operculum. ? Fossil, 5 species. Miocene—. Dax; Turin. CycLopHorus, Montfort. Etymology, Cyclos, circle, phoreus, bearer. Type, C. involutus, Pl. XII., Fig. 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. C. gibbus, Fer. (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. Pterocyclos (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), Guilding (Aperostoma, Troschel). Shell depressed, widely umbilicated; operculum shelly, whorls numerous, with raised margins. Distribution, 44 species. West Indies, Tropical America, India, Asiatic i Fossil, Hocene, Isle of Wight. (I. Edwards). Leptopoma (perlucidum), Pfeiffer. Shell ‘arbinakedl peristome sinple, reflected; operculum membranous. Distribution, 20. . GASTEROPODA. 3809 species. Philippines, India, New Guinea, New Zealand, Pacific Islands. Lomastoma* (cylindraceum), Guild. (Farcimen, Troschel.) Shell oblong or pupa-shaped, scarcely perforated, aperture circular; operculum thin, horny, many-whorled, flat. Distri- bution, 19 species. West Indies, Tropical America, Canaries, India, Mauritius. Fossil, Hocene—. 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. O. biciliatus, Mouss. Shell like Pterocyclos ; operculum double, margin grooved, interior concamerated. Distribution, 4 species. Singapore, Borneo, Java. Hybocystis, Benson, 1859. Shell distortedly ovate; aperture circular, interior peristome deeply notched. Operculum shelly, thick, multi-spiral. Purina, Vignard. Type, P. bicanaliculata, Sby. Pl. 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 Ive- 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 severai preposterously long names, allowed this to remain. 310 MANUAL OF THE MOLLUSCA Heticina, Lamarck. Type, H. Neritella, Lam. Synonyms, Oligyra, Say. Pachytoma, Sw. Ampultina, Bl. Pitonillus, Montfort. Shell globose, depressed or keeled, callous beneath; 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-genera. Lucidella (aureola), Gray. 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, Pl. XII., Fig. 43. Jamaica. Shell helix-shaped, often velvety, callous beneath; columella flattened, straight; peristome shit in front; operculum shelly, semi-ovate, with a tooth-like process adapted to the sht in the peristome. Distribution, 17 species. Cuba, Jamaica, and Hayti. SToAsToMA, C. B. Adams. Etymology, stoa, pillared, stoma, mouth. Type, S. pisum, Ad. Sheil 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. succinewm (Electrina, Gray) has smooth whorls. I. Opara, Polynesia. 60 new species haye been added by the Hon. E. Chitty, who divides them ‘among several new genera. Famity VII.—AcicuLipz. 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. ‘ype, A. fusca, Pl. XII., Fig. 44. —_— > = GASTEROPODA. 311 Synonym, Acme and Acmaea, Hartmann.* Shell minute, slender, nearly imperforate; peristome slightly thickened, margins sub-parallel, joined by a thin callus; oper- culum hyaline. Distribution, 7 species. Britain, Germany, France; Vanicoro (on leaves). A. fusca is found in low, marshy situations, at the roots of grass; it occurs fossil in the Newer Phocene 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. Distribution, 21 species. Jamaica. ORDER IIJ.—OPISTHO-BRANCHIATA. Shell rudimentary or wanting. Branchie 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 molluscs of this order may be termed sea-slugs, since 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 papille, 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 Bullide. In * All given in the same year, 1821, the name Acmaea having been employed by Eschscholtz for a genus of limpets; Acicu/a has been retained by Pfeiffer and Gray for this land-shell. 312 MANUAL OF THE MOLLUSCA. Philine aperta there is no central tooth; and the laterals, which increase rapidly in size backwards, have a finely denticulated — membranous inner edge. In Tornatella and Bulla (physis) the rachis is unarmed, and the lateral teeth are nume- rous and similar; in Acera, Cylichna, and Amphisphyra 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 Fig. 136. Philine aperta. (Wilton.) state of the mollusca 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. SEecTIoN A.—TECTI-BRANCHIATA.f Animal usually provided with a shell, both in the larval and adult state; branchize covered by the shell or mantle; sexes united. Famity I.—ToRNATELLIDA. Shell external, solid, spiral or convoluted; sub-cylindrical ; * In the cuttle-fishes and pteropods it is bent upon itself ventraily, 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.) + Mono-pleuro-branchiata. Bl. Pomato-branchia, (from poma, a lid). Wiegm. The order Tecti-branchiata of Cuvier included only the family Bullide ; it is here made to comprise the /nfero-branchs also ; no object being cana by the multiplica- tion of descriptive epithets. ~ GASTEROPODA. 313 aperture long and wuarrow; 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 Pyramidellide 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 Bullide; and the outer lip often remarkably thickened, as in Auricula. TORNATELLA, Lamarck. Type, T. tornatilis, Pl. XIV., Fig. 1. Synonyms, Actzeon, Montf. (not Oken), Dactylus (solidulus), Schum. ? Monoptygma (elegans), Lea. Shell solid, ovate, with a conical, many-whorled spire; 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, Red Sea, Philippines, Japan, Peru. JZ. tornatilis inhabits deep -water—60 fathoms. (Forbes.) Fossil, 70 species. Trias—Lias—. North America, Europe, South India. — Sub-genera. Cylindrites (Llhwyd), Lycett. CO. acutus, Sby. Pl. XIV., Fig. 2. (A.) Shell smooth, slender, sub-cylindrical, spire small, aperture long and narrow, columella rounded, 2 814 - MANUAL OF THE MOLLUSCA. twisted, and directed slightly outwards. (B.) Shell oval, spire © sunk, whorls with acute margins. Bath Oolite, Britain. | Acteonina, D’Orbigny. Tornatelle ‘‘ without columella — plaits,” 30 species. Carb.—Portlandian (including Cylindrites). Acteonella, D’Orbigny. A. Renauxiana, Pl. XIV., Fig. 3. Shell thick, cone-like or convoluted, spire short or éonbealeds aperture long and narrow, columella with 3 strong and regular spiral plaits in front. Distribution, 18 species. Chalk; Britain, © France. Acteon Cabanetiana, D’Orbigny. (Itieria, Matheron, 1842), Coral-rag, France, belongs to the genus Nerinwa (D’Orbigny), p. 244. CINULIA, Gray. Type, O. avellana, Pl. XIV., Fig. 4. Synonyms, Avellana and Ringinella, 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, France. RINGICULA, y. p. 222, Pl. V.,. Fig. 21. GuopiconcHa, D’Orbigny. Type, G. rotundata, D’Orbigny. Fossil, 6 species. Chalk. France. Shell ventricose, smooth, aperture crescent-shaped, simple, not toothed or thickened on the columellar side. VARIGERA, D’Orbigny. 1850.* Type, VY. Guerangi, D’Orbigny. Fossil, 8 species. Neoc:—. Chalk. France. Shell like Globiconcha, but with lateral varices. TyLOsTOMA, Sharp. 1849. Type, T. Torrubize, Sharp. Etymology, Tulos, a callosity, stoma, mouth, Shell ventricose, smooth or punctate-striate, spire moderate, aperture ovate-lunate, pointed above, rounded in front; outer if lip periodically (once or twice in a whorl) thickened inside and expanded, rising slightly; inner lip callous, spread over body whorl. Distribution, 4 species. LL. Cretaceous rocks, Portugal. * The dates of M. D’Orbigny’s genera, given in the Prodrome de Paleontologie, dates of invention ; the names were not published, in many instances, until years afterwards, GASTEROPODA. 315 ? PreropontTA, D’Orbigny. Type, P. inflata, D’Orbigny. Fossil, 8 species. Chalk. France. Shell oblong, ventricose, spire elongated ; aperture oval, lip slightly expanded, notched in front, and with a tooth-lke ridge internally, remote from the margin. ? ToRNATINA, A. Adams. Type, T. voluta. Pl. XIV., 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 Lovén, to Ovulum by Forbes. Distribution, 12 species. Britain, Medi- terranean, Asia. ossil, Pliocene—. Suffolk. Famity 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-podiwm), 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 Bullide is formed 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 olfactory ganglia; the anterior portion of the disk receives branches from the labial nerve, which comes from the front margin of the cerebroid, ( Hancock.) P2 815 MANUAL OF THE MOLLUSCA. The Bullide are animal feeders; they are said to use their lateral lobes for swimming. 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. Buta, Lamarck. Bubble-shell. Type, B. ampulla, Pl. XIV., 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 furnished with 3 chiton-like plates; teeth. ? Bulla naucum (Atys, Montf. Alicula, Ehr. Rowania, Leach). Pl. XIV., Fig. 7; has the columella twisted, and the spire entirely concealed. Distribution, 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. Sub-genera 2? Crypt-opthalmus (smaragdinus), Ehr. Red 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. Iutea, 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, Chie ; Smaragdinella, A. _ Adams), Bulla viridis, Rang. Pl. XIV., 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 enyelop- — ing. | AcERA, Miiller. Type, A. bullata, Pl. XIV., Fig. 9. & Etymology, Akeros, hornless. 2) 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; columella 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. Greenland, Britain, Mediterranean, Zanzibar, India, New Zealand. A. bullata is found amongst weed, in 1—15 fathoms water. (Forbes. ) CYLICHNA, Lovén. Type, C. cylindracea, Pl. XIV., Fig. 10. Synonym, Bullina, Risso. Sheil strong, cylindrical, smooth or punctate-striate; spire minute 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, Red Sea, Australia. Fossil, Tertiary—. Britain. ? KLEINELLA, A. Adams. Shell thin, dotted, striated, columella smooth, spire obtuse. Distribution, 1 species. Japan. AMPHISPHYRA, Lovén. Type, A. pellucida, Johnst. (Amphi-sphyra, double hammer) Synonyms, Utriculus (part), Brown. Rhizorus, 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. 318 MANUAL OF THE MOLLUSCA. Distribution, 7 species. United States, Norway, Britain, Borneo, Mexico. Buccrnvuuvs, Blanchard. Shell thick ; columella with two plaits; aperture small, entire in front. Distribution, 10 species. South Seas. APLUSTRUM, Schumacher. Type, Bulla aplustre, Pl. XIV., Fig. 11. Etymology, aplustre, a ship’s flag. Synonyms, Bullina, Fér. 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) 13.0.138, serrated. Distribution, 10 species. United States, West Indies, Mauri- tius, Ceylon, China, Australa. ScAPHANDER, Montfort. Type, S. lignarius, Pl. XIV., 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 Dentaliwm entale. Distribution, 13 species, United States, Norway, Britain, Mediterranean on sandy ground; 50 fathoms. Fossil, 8 species. KHocene—. Britain, France. PHILINE (Ascanius, 1762). Type, B. aperta, Pl. XIV., Fig. 13. Synonym. Bullea. Lamarck. Shell internal, white, translucent, oval, slightly convoluted, spire rudimentary. Animal pale, slug-like; mantle investing the shell; head GASTEROPODA. 319 oblong; eyeless; foot broad; lateral lobes large, but not enveloping; tongue with two or four series of sickle-shaped uncini; gizzard with three longitudinal shelly plates. Egg Fig. 138. Philine aperta.* capsules ovate, in single series on a long spiral thread; fry with a ciliated head-veil and an operculated, spiral shell. (Loyén.) . Distribution, 16 species. West Indies, Greenland, Norway, Britain, Mediterranean, Corea, Borneo. Fossil, 7 species. Eocene—. France. Sub-genus. Chelidonura, A. Adams, (Hirundella, Gray) B. hirundinaria, Quoy, 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. Doripium, Meckel. Etymology, diminutive of Doris. Synonym, Acera, Cuvier. Eidothea, Risso. Type, D. membranaceum, Meck. 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. GASTROPTERON, 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 ; 0, mouth; c, head, or cephalic disc, 7, side-lobes of the foot; m, mantle. The shell s, and gizzard g, are indistinctly seen through the translucent integuments. 320 MANUAL OF THE MOLLUSCA. gill, excretory opening behind it. Longitude 1, latitude 2 inches. 2 species. PurysEmMaA, 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, thin, and transparent. . Atlas (Peronii, Bl.), Lesueur. Head with two small tentacular lobes; body con- tracted in the middle; foot dilated circularly, and fringed at the margin Famity IJI.—APpiLystap&. Shell wanting, or rudimentary and covered 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. APLystIA, Gmelin. Sea Hare. Type, A. depilans, Pl. XIV., Fig. 14. Synonym, Siphonotus (geographicus) Ad. Shell oblong, convex, flexible, and translucent, with a pos- terior shughtly incurved apex. Ammal 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 capable 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, whivh does rot injure the skin, has but a faint smell, and changes to wine-red. GASTEROPODA. 821 (Goodsir.) In old times they 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. Sub-genus. Aclesia (dolabrifera), Rang. Shell trapeziform. Side-lobes closely enveloping the body, leaving only a small dorsal respiratory opening, surface ornament with filaments. 9 species. Hast Indies. DoLABELLA, Lamarck. Type, D. Rumphu, Pl. XIV., Fig. 15. Hitymology, 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. Distribution, 12 species. Mediterranean, Mauritius, Ceylon, Society Islands, Sandwich Islands. STYLOCHEILUS, 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. DOLABRIFERA, Grube. Shell trapezoidal ; side-lobes not used for swimming. Distribution, 4 species. Indian Ocean, West America, SIPHONOPYGE, Brown. Shell truncated in front ; foot-lobes spread out for swimming; posterior part extended beyond the siphon. Distribution, 6 species. West America, Chinese Sea. Norarcuvs, Cuvier. Type, N. Cuvieri, Bl. Etymology, notos, the back, archos, vent. Synonym, Busiris (griseus), Risso, ? Bursatella (Leachii), Bl. * Aplysia (from a and pluo) un-washable: the Aplysia of the Greek fishermen were sponges unfit for washing. Pd 3822 MANUAL OF THE MOLLUSCA. dendritic, foot narrow, lateral crests united, leaying only a narrow branchial slit ; gills not covered by an opercular mantle lobe. Animal shell-less, ornamented with filaments, vor Distribution, 7 species. Mediterranean, Red Sea. , Icarus, Forbes, 1843. Type, I. Gravesu, F. Synonym, Lophocercus (Sieboldtii) Krohn, 1847. Shell like Bulleea; 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. | LosbicER, Krohn. Type, Lu. Philippi, 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 species. Atlantic; South Europe. FamiIty I[V.—PLEUROBRANCHIDA. 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. PLEUROBRANCHUS, Cuvier. Example, P. membranaceus, Pl. XIV., Fig. 17. Etymology, pleura, side, branchia, gill. Synonyms, Berthella (plumula), Bl. Oscanius (membr.), Gre 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 ) 7 GASTEROPODA. 323 base of the 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, Red Sea, Ceylon. Sub-genus? Pleurobranchea, Meckel; P. Meckellu, Leve, Mediterranean. Synonym, Pleurobranchidium (maculatum), Quoy, South Australia. Mantle-margin very narrow, not concealing the gill; dorsal tentacles ear-like, oral veil tentacu- liform. PosTEROBRANCHEA, 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. Runoina, (Forbes) Hancock. Type, R. Hancocki, Forbes. Synonym, ? Pelta, 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 Conferve near high-water mark, Torbay. NepA, 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. SusariA, Gribe. Shell small; mantle tuberculated, extending well over both head and foot ; notched in front. Distribution, 1 species. South Europe. UMBRELLA, Chemnitz. Chinese-umbrella shell. Type, U. umbellata, Pl. XIV., Fig. 18. Synonym, Acardo, Lam. Gastroplax, Bl. Shell, limpet-like, orbicular, depressed, marked by concentric 324 MANUAL OF ThE MOLLUSCA. : lines 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 veil; 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 flee posterior, tubular. Distribution, 6 species. Canaries, Mediterranean, India, China, — Sandwich Islands. Fossil, 4 species. Oolite—. United States, Sicily, Asia. TYLoDINA, Rafinesque. Type, T. punctulata, Raf. (= 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. | FamIty V.—PHYLLIDIADA. Animal shell-less, covered by a mantle, branchial laminzo arranged in series on both sides of the body, between the foot and mantle. Sexes united. PHYLLIDIA, Cuvier. 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 Febutt of the mantle; mouth with two tentacles; foot broadly oval; gills forming a series of lamine 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, Red Sea, India. GASTEROPODA. 825 FRYERIA, Grube. Excretory orifice on the side of the foot under the mantle, which is leathery and warty; 6 gills entire length of both sides. Distribution, 1 species. South Sea, East Africa. HYPOBRANCHIHA, A. Adams, Mantle cuticular; gills limited to the hinder part of the body ; excretory orifices at the side, under the mantle. Distribution, 1 species. Japan. DIPHYLLIDIA, Cuvier. Type, D. Brugmansii, Cuvier. Synonym, 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. Distribution, 9 species. Norway, Britain (D. lineata, Otto), Mediterranean, India. SECTION B.—NUDIBRANCHIATA. Animal destitute of a shell except in the embryo state; branchize 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 Ray 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 cloak 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 ” 826 MANUAL OF THE MOLLUSCA, mantle whatever. The eyes appear as minute black dots, immersed in the skin, behind the tentacles; they are well organised and conspicuous in the young, but often invisible in the adult. The dorsal tentacles are laminated, like the antennze 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 above the cesophagus; three pairs are larger than the rest, the cerebroid in front, the branchial behind, and the pedal ganglia at the sides. The cerebroid supplies neryes to the tentacles, mouth, and lips. The olfactory ganglia are sessile on the front of the cerebroid (in Doris), or situated at the base of the tentacles (in .Aolis), 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 cesophagus, 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-cesophageal) 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. Besidés this ewcito- 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. ft The digestive organs of the Nudibranchs present two remark- able modifications: in Doris and Tritonia the liver is compact * The auditory capsules of other Mollusca (excepting the Nucieobranchs) are attached to the posterior side of the pedal (sub-c@sophageal) ganglia, + 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 Mollusca was first clearly demonstrated by MM. Hancock and Embleton, The ezcito- motory system of the Mollusca corresponds with the cerebro-spinal system of tne vertebrata. GASTEROPODA. 327 and the stomach a simple membranous sac; whilst in 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 ceecal prolongations of the stomach; the coeca extend into a series of gill-like processes, arranged upon SN Fig. 189. Dendronotus arborescens. the back of the animal, which also contain part or the whole of the true liver; the gastric ramifications vary exceedingly in amount of complexity. The Doridide are distinguished by having a short and wide lingual membrane with numerous similar teeth ; the Aolids 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, Pl. II., Fig. 8.) The only Nudibranch with a solid upper jaw, is Mgirus | punctilucens (A. and H., Pl. XVII., Fig. 15). In other instances the two halves are articulated and act as lateral jaws. In Hyirus the mouth is also furnished with membranous fringes (A. and H., Pl. XVIL., Fig. 14). Ancula cristata has a for- midable spinous collar (Pl. XVII., Fig. 7). Fig. 140. a, Mouth of _Aigirus punctilucens. 6, Horny upper mandible detached. c, Prehensile collar of Ancula. a, mantle ; z, dental sac ; 4, insertion-plate of mandible ; c, passage of mouth, The vascular system and circulation of the ntudibranchiate 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 s’nus and into a network of 828 MANUAL OF THE MOLLUSCA, sinuses in the skin, from which it returns to the auricle by two lateral veins, without having circulated through the gills. The heart is contained in a pericardium to which is attached a small ventricle, 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 Holis there are no special gills, but the gastro-hepatic papillee 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 Hlysiade, and in the other families, when by accident the branchize 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.) | Famity VI.—Dorin@.* 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. Doris, 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 thehead © 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, Fig. 29). * Contracted from Doridide ; as the Greeks used Deucalides for Deucaliontiades, Ehrenberg divided the genus Doris into sections by the number and form of the gills, characters of only specific importance. GASTEROPODA. 329 Sub-genus. Oncidoris (Bl?). D. bilamellata, Johnst. 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 (Villiersia), D’Orbigny, Rochelle ; 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. - HEPTABRANCHUS, A. Adams. Mantle without a longitudinal ridge on the back; 7 gills arranged in a semicircle; oral tentacles star-shaped. HEXABRANCHUS, 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 clayate, retractile ; gills very small. Distribution, 1 species. New Zealand. Aoctinocycius, Ehrenberg. Animal ovate; back naked ; gills very plumose. Distribution, 7 species. East Africa and South Europe. CHROMODORIS. _ Animal almost quadrangular; back naked; feathery gills _ arranged lineally. Distribution, 1 species. Hast India. } ASTERONOTUS, Ehrenberg. __ Animal ovate: the apertures for the gills and tentacles almost - closed. __ Distribution, 2 species. East Africa and South Europe. GLossoporis, 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, 7 species. East India and West America. 530 MANUAL OF THE MOLLUSCA. GoNnIoDORIS, Forbes. Etymology, gonia, an angle. Type, G. nodosa, Pl. XIII., Fig. 2. Animal oblong; tentacles clavate, laminated, non-retractile ; mantle small, simple, exposing the head and foot. Spawn coiled irregularly. , Distribution, 26 species. Norway, Britain (2 species), Medi- terranean, China. Between tide-marks. TRIOPA, Johnston. Type, T. claviger, Pl. XITT., Fig. 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. ZAGIRUS, Lovén. Type, ZA, punctilucens, Pl. XIII., Fig. 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), France. Littoral zone. THECACERA, Fleming. 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. and H.) ed Distribution, Britain, 2 species. Length, ;—} inch, Found at low water. PoLycERA, Cuvier. Etymology, poiycera, many horns. Type, P. quadrilineata, Pl. XIII., Fig. 5. Animal oblong or elongated; tentacles laminated, non- retractile, sheathless; head-veil bordered with tubercles or cue} | \Glvcimeris \ AREA us Limasina tlio Pecten xT + re | I 5 | Sect loltenia les? / Lh, i : Oe VS oy ey L Pihdiunn ee a aes sda) = arg arula =~ Ttmatda (hea | Patella il | Aleutian , Macherra |, Sawidomus a> Bi BOE fe Wf, YY Petricola z

-/ prolonged on each side into a RT \ ) pair of large membranous palpi TART Ta (t). The gills (7) are placed two. on each side of the body, and are attached along their upper, or dorsal margins ; behind the body they are united to each other Fig. 207. Mya arenaria. ¢ * Alder and Hancock on the branchial currents of Pholas and Mya. An, Nat, Hist., Nov. 1851. + 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; b, body; c, cloaca; f, foot; g, branchize; h, heart; m, cut edge of the mantle ; 0, mouth; s, s', siphons; ¢, labial tentacles; v, vent. The arrows indicate the 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. f CONCHIFERA. 397 and to the siphonal partition. Each gill is composed of two lamin, divided internally into a series of parallel tubes, indicated outside by transverse lines; these tubes open into longitudinal channels at the base of the gills, which unite behind the posterior adductor muscle at the commencement of the exhalent siphon (c). Examined by the microscope, the gill laminz 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 offices; 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 gull, 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 Mya, 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 6). 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 ‘‘dorsalchannels” still exist,and carry out the filtered water. In some genera the gills subserve a thizd 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 (Fig. 208, 0, 0). 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 Conchifera are bound together by an elastic ligament, and articuiated 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 yalve is a hollow cone, with the apex turned more or * Some other particulars respecting the organisation and development of bivalve shell-fish are given in ChapterI. For an account of their vascular system see Milne- Edwards, An. Sc. Nat. 1847, tom, viii. p. 77. 398 MANUAL OF THE MOLLUSCA. less to one side; the apex is the point from which the growth of the valve commences, and is termed the beak, or wmbo (p. 29). The beaks (wmbones) are near the hinge, because that side grows least rapidly, sometimes they are quite marginal; but they always tend to become wider apart with age. The beaks are either straight, as in Pecten ; curved, as in Venus; or spiral, as in Jsocardia 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 /eft- handed spiral like the reversed gasteropods. When ene valve is spiral and the other flat, as in Chama ammonia (Fig. 224), | ; | | | } Fig. 208. River-mussel. (Anodon cygneus 9) * the resemblance to an operculated spiral univalye becomes arg striking, The relation of the shell to the animal may be readily deta mined, in most instances, by the direction of the wmbones, 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 shies from the centres of the closed valves: + The Conchifera are mostly eqguivalve, the right and left valves: : * The valves are forcibly opened and the foot (7) contracted; a, anterior alangean! muscle, much stretched; p, p, palpi; g, inner gills; 0, 0, outer gills distended with spawn; 0, d, a bristle passed through one of the dorsal channels. + Linnzus and the naturalists of his school described the front of the shell as Her back, the left valve as the right, and vice versa. In those works which have been compiled from ‘ original descriptions” (instead of specimens) sometimes one end, sometimes the other, is called wnterior; 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. CONCHIFERA. 3899 being of the same size and shape, except in the Ostreide and a few others. In Ostrea, Pandora, and Lyonsia, the right valve is smallest; in Chamostrea and Corbula, the left; whilst the Chamacee follow no rule in this respect. The biyalyes are all more or less inequilateral, the anterior Dorsal Margin. ) Anterior * Hall and Salter employ the name Orthonotus for such shells as Solen constrictus Sandb. Devonian, Germany; Sanguinolites anguliferus, M’Coy, U. Silurian, Kendal ; and Solenopsis minor. M’Coy, Carb. limestone, Ireland. M. D’Orbigny has mistaken the plaits for teeth, and placed the genus with Nucula. The recent M. plicata, Lam., from Nicobar Islands, has the same long, straight back and plaited dorsal region. 494 MANUAL, OF THE MOLLUSCA, " to which 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. Hutopo, America, Africa, } Fossil, 13 species. Eocene—. Britain, Germany. | Famity ITV.—ARCADA. Shell regular, equivalye, 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 strive. (Carpenter.) Animal with the mantle open; foot large, bent, and deeply grooved ; gills very oblique, united posteriorly to a membranous , septum. Arca, L. a | Etymology, arca, a chest. Type, A. Now, Pl. XVII., Fig, 12. a Synonyms, Barbatia, Grays Anomalocardia, Klein; Scaphaie + Gray; Scaphula, Benson. i Examples, A. granosa, Pl. XVII., Fig. 10. A. pexata, Fig. lL. A. zebra, Fig. 13. @ Shell equivale or nearly so, thick, sub-quadrate, ventricose, strongly ribbed or cancellated; margins smooth or dentated, close or sinuated ventrally; hinge straight, teeth very none transverse; umbones anterior, separatod by .a flat, ioze shaped ligamental area, with numerous cartilage f pallial line simple; posterior adductor impression double; pedal scars 2, the posterior elongated. ne Animal with along pointed foot, heeled, and deeply groved; mantle furnished with oceli; palpi 0; gills long, narrow, les striated externally, continuous with the lips; hearts two, eae! with an auricle. Ng The name Bysso-arca was chosen unfortunately by Swainson, for the typical species of the genus, in which the byssal is sometimes very large (Pl. XVII., Fig. 13). The byssu horny cone, composed of numerous thin plates, oceasio becoming solid and calcareous ; it can be cast off and re-fo with great rapidity. (Forbes.) The Arcas with close have the left valve a little larger than the er ornate. CONCHIFERA. 425 in crevices of rocks, and the empty burrows of boring mollusks ; they are often much worn and distorted. The genus Palearca 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, Vol. III., under the head Cyrtodonta. Distribution, 140 species. World wide, most abundant in warm seas; low water—230 fathoms (A. imbricata, Poli). Prince- Regent Inlet (A. glacialis). A scaphula, 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. Sy Fossil, 400 species. Lower Silurian—. United States, Europe, South India. : CucuLL&A, Lamarck. Etymology, cucullus, a cowl. Type, C. concamerata, Pl. XVIL., Fig. 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. XVII., Fig. 15. Sheil with a few oblique anterior teeth and one or more long laminar posterior teeth. The Ark-shells of the Palzeozoic and secondary strata have their anterior teeth more - or less oblique, ike Arca, the posterior teeth parallel with the hinge-line like Cucullea ; 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. - Pecruncutvs, Lam. Type, P. pectiniformis, Pl. XVII., Fig. 16. (Arca pectun- culus, L.) Shellorbicular, nearly equilateral, smooth or radiately striated; umbones central, divided by a striated hgamental area; hinge 426 MANUAL OF THE MOLLUSCA. with 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, New Zealand, West America; ranging from 8 to 60, rarely 120 fathoms. Fossil, 80 species. Neocomian—. United States, Europe South India. The teeth of Pectunculus and Arca 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, Pl, XVII., Fig. 17. Synonym, Trigonoccelia, Nyst. Pectunculina, D’Orb. 4 Shell orbicular, convex, slightly oblique; ligamental area with a trianguiar cartilage-pit in the centre; hinge with 2 equal, curved series of transverse teeth. Distribution, 4 species. Red Sea (Nyst.), Japan, Britain. — Mr. M‘Andrew has dredged Z. pygmea, living, on the coast of Finmark; it is a fossil of the Pliocene of England, Belgium, and Sicily. Fessil, 36 species. Bath-oolite—. United States Europe. Nucua, Lam. Etymology, diminutive of nux, a nut. Example, N. Cobboldiz, Pl. 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 z CONCHIFERA. 427 foot. N. mirabilis, Adams, from Japan, is sculptured like the extinct N. Cobboldic. Distribution, 70 species. United States, Norway, Cape, Japan, Sitka, Chil. 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. X VIL., Fig. 19. Shell minute; teeth few, in one series, with a posterior lateral tooth. Hocene, France. . 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. Hocene, Alabama. ? S.Nystti, Galeotti (Nucunella, D’Orb.). Eocene, Belgium. Shell like Limopsis; ligamental area narrow, wholly posterior. Isoarca, Minster, 1842. Type, I. subspirata, M. Oxford Clay, France, Germany. Synonym, 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. I. Logani (Ctenodonta), Salter, Lower Silurian, Canada, is 3 inches long, and has the ligament preserved. Fossii, 14 species. Lower Silurian—Chalk. North America. Europe. Sub-genera. Cucullella, M‘Coy. C. antiqua, Sby. Upper Silurian, Herefordshire. Shel/ elliptical, with a strong rib behind the anterior adductor impression. Iunularca, Gray. Part anterior to the umbo toothless, with a lunule. LEDA, Schumacher. Etymology, Leda, in Greek mythology, mother. of Castor and Pollux. Synonym, Lembulus (Leach) Risso. Example, L. caudata, Pl. XVII., Fig. 20. Shell resembling Nucula ; oblong, rounded in front, produced and pointed behind; margins even; pallial line with a suall sinus ; umbonal area with a linear impression joining the ante- rior adductor. Animal furnished with two partially-united, slender, unequul, * N. donaciformis, Parreyss, from the White Nile, is a crustacean! ‘Estheria.) 428 MANUAL OF THE MOLLUSCA. siphonal tubes (Forbes); gills narrow, plume-like, deeply laminated, attached throughout; 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). ‘i + AN a MA NA a 4 Jf eS i 7 AY GUN FA 7 \ SD ~ . eZ, GA 44) Wn" CONS. Fig. 219, Yoldia n. sp, 3, 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. er 7 a, a, adductors ; p, p, pedal muscles; 7, ligament; g, gills; s, siphons (much con-— tracted); t, c, labial palpi and appendages ; 7, intestine ; 7, foot ; z, z, lateral muscles ot the foot ; m, pallial line. Y. myalis, Pl. XVII., 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 shel he mantle-margiit plain in front, fringed behind; destitute of ventral lobes. Distribution, Arctic and Antarctic Seas, Green-— land, Massachusetts, Brazil, Norway, Kamtschatka. Yoldic be limatula (Fig. 220) has been dredged, alive, by Mr. M‘Andrew, on the coast of Finmark. Itis also found in Portland Harbour, Massachusetts. The animal is very active, and leaps to an astonishing height, exceeding in this faculty the scollop-shell CONCHIFERA. 429 (Dr. Mighels.) Fossil, Phocene—. (Crag and Glacial deposits.) England, Belgium. —— Fig. 220. Yoldia limatula (after Barrett). SoLENELLA, Sowerby. ) ¥ Type, 8. Norrisii, Pl. XVII., Fig. 22. 8. ornata, Fig. 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 fine 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; siphonal 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. Valparaiso, New Zealand (shell like S. ornata), Fossil, 1 species. Miocene. Point Desire, Patagonia. P SotEMYA, Lamarck. Type, 8. togata, Pl. XXII., Fig. 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 siphonal 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 laminz free to the base ; palpi long and narrow, nearly free. 430 MANUAL OF THE MOLLUSCA. The 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 ills. ; : Distribution, 4 species. United States, Canaries, West Africa (Gaboon River), Mediterranean, Australia, New Zealand. Burrowing in mud; 2 fathoms. Fossil, 4 species. Carb. —. Britain, Belgium. FAMILY V.—TRIGONIADZA. Shell 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. XVII., Fig. 24. T. pectinata, Fig. 221. ; Shell thick, tuberculated, or ornamented with radiating or : PO lay ut concentric ribs; posterior side — EE 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 Imm Iapression close to the umbo. Animal with a long and pointed foot, bent sharply, hee 5 prominent, sole bordered by two crenulated ridges ; palpi sma 1 and pointed; gills ample, the outer smallest, united behind t body to each other and to the mantle. The shell of Z'rigonia is almost entirely mes and. usuall y Fig. 221, 1 rigonia pectinata.* and exhalent currents: a, a', adductors ; A/, ligament ; ¢, t', dental sockets; 9, mic ut ; ¢ t, labial tentacles or palpi; p, pallial line; m, margin ; f, foot; v, cloaca. CONCHIFERA. 431 terior are called ‘‘ horse-heads” by the Portland quarry-men ;* they spoil the stone. Silicified casts have been found at Tisbury, in which the animal itself, with its gills, was preserved.¢ 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.8S. 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. Myornortia, Bronn, 1830. Type, M. vulgaris, Schl. Synonym, Cryptina (Kefersteinu), 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 T’rigonia. M. decussata, Pl. XVII., Fig. 25, has a lateral tooth at the dorsal angle of the left valve. Fossil, 16 species. Trias: Germany, Tyrol. Axinus, 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 shghtly 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 Dolabra securiformis, M‘Coy, pro- bably belong to this genus. Dolabra equilateralis, Amphidesma subtruncatum, with many others from the Paleozoic rocks, may constitute a distinct genus, but their generic character has yet to be discovered. Curtonotus. Salter. Thickened hinge-plate, with a single strong triangular central * See Plott’s Oxfordshire, T. vii. Fig. 1. t In the collection of the late Miss Benett of Warminster, now in Philadelphia, 432 MANUAL OF THE MOLLUSCA, tooth on each valve. Right valve plate with an obscure tooth behind the central one. Anterior muscular scar deep; pallial impression entire. Fossil, 6 species. Devonian, Britain. PSEUDAXINUS, Salter. Type, 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. LyRODESMA, Conrad, 1841. Type, li. plana, New York. Synonym, Actinodonta, Phil. Shell trigonia-shaped, rather elongated, with a striated pos- terior area; hinge with several (S—9) radiating teeth, striated across ; ligament external. Fossil, 4 species. Lower Silurian: Canada, United States, Britain. FAmMILy VI.—Union1p@. WNaides. 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 mantle-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 musselsare found in thepondsand 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 admirers of artificial systems ; fortunately, how- ever, M. D’Orbigny has ascertained that the Mulleria, which oi CONCHIFERA. 433 is fixed and mono-myary when adult, is locomotive and di-myary 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).+ This condition of the umbones is conspicuous in the great fossil Uniones of the Wealden, but cannot be detected in the Cardinie, and some other fossils formerly referred to this family. The outer gills of the female unionidz are filled with spawn in the winter and early spring; the fry spins.a delicate, ravelled byssus, and flaps 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. Unio, Retz. River-mussel. Etymology, unio, a pearl (Pliny). Example, U. litoralis, Pl. XVIII., 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. plicatus (Symphynota, Sw. Dipsas, Leach) has the valves produced into a thin, elastic dorsal wing, as in Hyria.t 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 sulphuric acid may sometimes be set free in river-water, by the decomposition of iron pyrites in the banks; but Prof. 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 shell (p. 38); Mr. Gask in has an example containing two strings of pearls, and another in the Brit. Mus. has a number of little josses made of bell-metal, now completely coated with pearl, in its interior. U 434 MANUAL OF THE MOLLUSCA. ; were usually found in old and deformed specimens; round — pearls about the size of a pea, perfect in every respect, were worth £3 or £4. (Dr. Knapp.) An account of the Irish pearl- fishery was given by Sir R. Redding, 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 ina 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. | Sub-genera, Monocondylea, D’Orbigny. M. Paraguayana, fi XVII. Fig. 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. X VIII., Fig. 3. Synonyms, Pachyodon and Prisodon, Schum. Shelli Arca-shaped, hinge-line straight, with a dorsal wing on the posterior side; teeth elon- gated, transversely striated. Distribution, 4 species. S. America. CASTALIA, Lamarck. Type, C. ambigua, Pl. XVIII., Fig. 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. Rivers of South America, Guiana, Brazil. . Anopon, Cuvier. Swan-mussel. Type, A. cygneus, Fig. 208, p. 398. Htymology, 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. Hocene—. Europe. M. D’Orbigny relates that he found great quantities of small Anodons (Bysso-anodonta Paraniensis, D’Orbigny) 4 lines 1 length, attached by a byssus, in the River Parana, aboy Corrientes. CONCHIFERA. 435 Trmpina, Lamarck. Synonyms, Mutela, Scop. Spatha, Lea (including Mycetopus). Leila, Gray. Type, I. exotioa, Pl. XVIIL, Fig. 5. Etymology, iris, the rainbow. Shell oblong; umbones depressed; hinge-line long, straight, attenuated towards the umbones, crenated by numerous unequal teeth ; hgament long and narrow. Animal with mantle-lobes united posteriorly, forming two short siphons; mouth and lips small; palpi immense, oyal ; gills united to the body. Iridina ovata (Pleiodon, Conrad) has a broader hinge-line. Distribution, 9 species. Rivers of Africa, Nile, Senegal. Mycetorvs, D’Orbigny. Etymology, mukes, a mushroom, pous, the foot. Type, M. soleniformis, Pl. XVIIL., Fig. 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. River Parana, Corrientes; River Amazon, Bolivia. ZATHERIA, Lamarck. Type, Ai. semilunata, Pl. XVIII., Fig. 7. (Aitherios, aérial.) Shell irregular, inequivalve ; 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) ; hinge 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. River Nile, from first cataracts to Fazool;* River Senegal. MULLERIA, Férussac. Dedicated to Otto Frid. Miller, author of the ‘‘ Zoologia Danica.” Type, M. lobata, Fér., Fig. 222. Synonym, Acosteea (Guaduasana), D’Orbigny. * The “ fresh-water oysters” discovered by Bruce, U 2 436 MANUAL OF THE MOLLUSCA. Shell when young free, equivalye, Anodon-shaped, with 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 irregular ‘‘ talon’ in front of the fixed valve; epidermis thick ; ligament in a marginal groove; interior pearly, muscular Fig. 222. Mulleria lobata, Fér. (Original.) impressions single, posterior. Fig. 222 represents the left, or attached valve, showing the single muscular impression, and projecting spur with the nucleus, consisting of both valves of the fry, united, and filled up with shell.* Distribution, River Magdalena, near Bogota, New Chgnndek Mr. Isaac Lea has determined the identity of Miilleria and Acostea by examination of Férussac’s type, and the suite of specimens, of different ages, in the collection of M. D’Orbigny.t SECTION B.—SIPHONIDA. Animal with respiratory siphons ; mantle-lobes more or less united. a. Siphons short, pallial line simple; Integro-pallialia. * M. D’Orbigny very liberally placed his suite of specimens of this remarkable genus in the British Museum. Oct., 1854. + The only specimen of Miilleriain England, prior to the acquisition of the D’Orbigny collection, was purchased many years ago by Mr, Thomas Norris of Bury, for £20. CONCHIFERA. 437 Famity VII.—CHAMID&. Shell inequivalve, thick, attached ; 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, Pl. XVIII., Figs. 8, 9. Synonym, Arcinella, 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, with two rows of tentacular filaments; siphonal orifices wide apart, branchial slightly prominent, fringed, anal with a simple valve ; foot bent, or heeled; liver occupying the umbo of the attached yalve only ; ovary extending into both mantle-lobes, as far as Fig. 223. Right side. Fig. 224. Left side. Fig. 225. Right side, with 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; 7, foot and pedal orifice; p, posterior pedal muscle; ¢, palpi; g, gills (contracted) ; /, liver; 0» ovarium ; d, dental lobes. the pallial line ; lipssimple, 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 MANUAL OF THE MOLLUSCA. The shell of Chama consists of three layers; the external, coloured layer is laminated by oblique lines of growth, with cor rugations at right angles to the laminz; 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, 1, m). Some Chamas are attached indiffer ently by either valve ; when fixed by the right valve the dentition is reversed, the left valve haying the single tooth. Chama 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? Monopleuwra; Matheron (= Dipilidia, Math.). M. imbricata, Math. Fig. 226. Neocomian, Southern France. RO Oo Fig. 225. Bi-radiolites, 3+ Fig 226. Monopleura, 4. p, point of attachment; /, 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 groups, adhering laterally, or rising one above the other; the casts of such as are known are quite simple — and chama-like, CONCHIFERA. 439 DicErAs, Lamarck. Type, D. arietinum, Pl. XVIII., Figs. 10 and 11, and Figs. 227 and 228, Shell sub-equivalye, attathed by either umbo; beaks very prominent, spiral, furrowed externally by hgamental grooves; hinge very thick, teeth 2.1, prominent; muscular impressions bounded by long spiral ridges, sometimes obsolete. Distribution, 5 species. Middle oolite. Germany, Switzer- land, France, Algeria. Diceras differs from Chama in the great prominence of both its wmbones, in having constantly two hinge-teeth in the right Fig. 227. Diceras arietinum, 3. Fig. 228. Requienia ammonia, +. a, point of attachment ; 7, /, 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 Cucullea, 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) 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. REQUIENIA, Matheron, Dedicated to M. Requien, author of a Catalogue of Corsican Mollusca. Example, R. Lonsdaliu, Pl. XVIII., Fig. 12 and Fig. 230. R. ammonia, Fig. 189. Shell thick, very inequivalvye, attached by the /e/t umbo; liga- meut external; teeth 2:1; left valve spiral, its cavity deep, 440 MANUAL OF THE MOLLUSCA. not camerated ; free valve smaller, sub-spiral; posterior ad- ductor bordered by a prominent sub-spiral ridge in each valve. The shell structure of Requienia is like that of Chama. The relative size of the valves is subject to much variation ; in R. Fig. 229. Diceras, 3. Fig. 230. Requienia, + Internal casts; a, point of attachment; c, c', casts of dental pits; ¢, ¢', furrows produced by spiral ridges. (Mus. Brit.) Favri (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, #’). In R. sub- @qualis and Toucasiana there is a second parallel ridge, as in Hippurites and Oaprotina. Fossil, 7 species. Neocomian — L. Chalk. Britain, France, Spain, Algeria, Texas. Famity VIII.—Hr1ervuriripm. (Order Rudistes, Lamarck.) Shell inequivalye, 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. Roemer has found them in Texas and Guadaloupe. The structure of these shells has been fully described in the Quarterly Journal of the CONCHIFERA: 441 Geological Society 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 laminee are corrugated, leaving irregular pores, or tubes, parallel with the long axis 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. x1. 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 eyidence of a large internal ligament. 5. 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 Radiolite consists of prismatic cellular structure (Fig. 232); the prisms are perpendicular to the shell-laminz, and often minutely subdivided. The cells appear to have been empty, like those of Ostrea (p. 407).¢ 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, Buch regarded them as Corals. 1840, Leonh. and Bronn Jahrb. p. 573. 2. Desmoulins, as a combination of the Tunicary and Sessile Cirripede. 3. Dr. Carpenter, as a “ group intermediate between the Conchifera and Cirripeda.” An. Nat. Hist. XII. 390. . Prof. Steenstrup, of Copenhagen, as Annelids. . Mr. D. Sharpe refers Hippurites to the Balani; Caprinelia to the Chamacee. . La Peyrouse considered the Hippurites Orthocerata ; the Radiolites, Ostracea, . Goldfuss and D’Orbigny place them both with the Brachiopoda. . Lamarck and Rang, between the Brachiopoda and Ostracee, . Cuvier and Owen, with the Lamellibranchiate bivalves. . Deshayes, in the same group with theria. 11, Quenstedt, between the Chamacee and Cardiacee.’ + This is very conspicuous in Radiolites from the chalk ; a formation in which other prismatic-cellular fossils are solid. 3 : : U — oO ONS Oh 442 MANUAL OF THE MOLLUSCA. is seldom compact, its lamellz are extremely thin, and separated by intervals like the water-chambers of Spondylus; similar spaces occur in the deposit, filling the umbonal eayity 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 ; SS Fig. 231, Section of a fragment of Ostrea Cornucopie. 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 r U i a 6 signees: LM Fig. 232. Part of the rim of Radiolites Mortoni, Mantell.t Crania (Figs. 193, 194), and constitute the only argument for supposing the Rudistes 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 Amplerus and Cyathophyllum. A section of Hippurites bi-oculatus passing through only one of the detital sockets, resembles an Orthoceras with a lateral siphuncle; whilst a Caprinella (Fig. 246), which has lost its outer layer, mi; ht be mistaken for an Ammonite. } Traced from the original specimen in the Museum of the School of Mines. 3, is the inner edge ; a, the outer edge; v, v, the dichotomous impressions; the horizontal lamine are seen on the shaded side. Lower chalk; Sussex. oe CONCHIFERA. 443 occur on the rim of the shell, and not on the disk, as in Crania.* The chief peculiarity of the Hippuritide is the dissimilarity in the’structure of the valves, but even this is deprived of much significance by its inconstancy.t The free valve of Hippurites 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 epidermis. In the closely allied genus Radiolites 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 haye been exactly suited by its position and magnitude , but it is probable that, like other bivalves, they opened to a very small extent. HIPruRITES, Lamarck. Name, adopted from old writers, ‘‘ fossil Hippuris,” or Horse-tail. Types, H. bi-oculatus, Lamarck, and H. cornu-vaccinum, Fig. 237. Shell very inequiyalve, inversely conical, or elongated and cylindrical; fixed valve striated or smooth, with three parallel furrows (/, m, m) on the cardinal side, indicating duplicatures of the outer shell layer; internal margin slightly plaited; pallial line continuous ; umbonal cavity moderately deep, ligamental inflection (7) 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. ; The lower valves of some Spondyli are squamous or spiny, the upper plain; those of many oysters, 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 Rudistes has a parallel in Rhynchonella and Terebratula (p. 360), and in the condition of the hepatic organ in Zritonia and Dendronotus. { The valves of Crania are perforated by branching tubuli, but in that case they pass . vertically through every part of the shell, ar all its layers (p. 361). 444 MANUAL “OF THE MOLLUSCA. small, very deep, bounded by the second duplicature (m); third duplicature (7) projecting into the umbonal cavity: free valve Fig. 233, Interior of lower valve, 3. Fig, 234. Upper valve (restored). Hippurites radiosus,Desm. Lower chalk, St. Mamest, Dordogne.* a, a, adductor impressions and procesges; c, ¢, cartilage pits; t, t', teeth and dental sockets; u, umbonal cavity; p, orifices of canals; J, ligamental inflection; m mus- cular, ” siphonal inflection. depressed. with a central umbo, and two grooves or pits cor- Fig. 235. H. Toucasianus, upper valve, 3.4 Fig. 236. Lower valve, with mould, % Z ligamental, m muscular, m siphonal inflections; , fracture, showing canals}; c, cartilage ; u, left umbo; the arrows indicate the probable direction of the branchial currents. responding to the posterior ridges in the 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. 7 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, CONCHIFERA, 445 porous, the pores leading to canals in the outer shell-layer, which open round the pallial line upon the inner margin ; anterior cartilage-pit deep and conical, posterior shallow; umbonal cavity turned to the front (uv); 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 hgamental inflection (/) is very deep and narrow, and the anterior tooth farther removed from the side than in H. bi-oculatus and radiosus (Figs. 238, 234); the posterior apophysis (a’) does not nearly fill the corresponding cavity in the lower valve. In H. bi-oculatus and some other species there is no ligamental ridge inside; 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 Pholas, Clavagella, and the caudate species of T'rigonia. The development of processes from the upper valve, for the ue WV COE Cx < eecee Ss eer . a4 acexe i iL hhh hit tbh Stan as Be Fig. 237. Longitudinal section ; upper half,2. Fig. 238. Transverse section, 4. Hippurites cornu-vaccinum, Bronn. Salzburg, 1, m, n, Guplicatures ; uv, umbonal cavity of left valve; 7, of right. valve; ¢, c', cars tilage-pits; t, ¢’, teeth; a, a’, muscular apophyses; d, outer shell-layer. Fig. 237 is taken in the line d 6 of Fig. 238, cutting only the base 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 shell-texture deposited by the anterior adductor (a). % attachment of the adductor muscles harmonises with the other peculiarities of the Hippurite. The equal growth of the margins 446 MANUAL OF THE MOLLUSCA. 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 Chama, 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 i | -6 ora ' CONCHIFERA,. 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 T'ridacna, as seen on removing the left valve 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 Hippopus are found in the raised coral-reefs of Torres Straits. (Macgillivray.) Sub-genus. Hippopus, Lamarck. H. maculatus, Pl. XVIII., 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 byssus. FAMILY X.—CARDIADA. Shell regular, equivalve, 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 large, sickle-shaped. Carpium, L. Cockle. Etymology, 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- nent, sub-central; margins crenulated; pallial lne 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 (C. edule) 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. rusticwm 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 along time in the lagoon (of Keeling Id.), examining the fields of: corel and the gigantic clam-shells, into which if aman were to put his hand, he would not, as long as the animal lived, be able to withdraw it.” (Darwin’s Journal, p. 460.) 454 MANUAL OF THE MOLLUSCA. Sub-genera. Hemicardium (Cardissa) Cuvier. C. hemicardium, Pl. XIX.. Fig. 3. Shell depressed, posterior slope flat, valves” prominently keeled. Lithocardium avyiculare, Pl. XVIII., Fig. 17. Shell triangular, | keeled; anterior side very short; hinge-teeth 1.2, directed backwards ; posterior laterals 2.1; anterior muscular pit minute, posterior impression large, remote from the hinge. L. cymbulare, Lam,. exhibits slight indications of a byssal sinus in the front margins of the valves. Fossil, Eocene, France. These shells present considerable resemblance to T'ridacna. Serripes (groenlandicus) Beck. Hinge edentulous. Arctic Seas, from C. Parry to Sea of Kara; fossil in the Norwich Crag. Fig. 253. C. leviusculum, Eichw. (after Middendorff), Adacna, Hichwald. C. edentulum, Pl. XTX., 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 theend, plain. Distribution, 8 species. Aral, Caspian, Azof, Black Sea, and the embouchures of the Wolga, Dniester, Dnieper, and Don; burrowing in mud. (.— Caspicum (Monodacna, Hichw.) has a single hinge-tooth, and C. trigonoides (Didacna, HE.) rudiments of two teeth. The siphonal inflection varies in amount. Distribution, 200 species. World-wide; from the sea-shore to 140 fathoms. Gregarious on sands and sandy mud. Fossil, 330 species. Upper Silurian —. Patagonia 7 Southern India. C. Hillunum, 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. CoNnocaARDIUM, Bronn., Synonyms, Tiychas, Stein. Pleurorhynchus, Ph. Lunulo- cardium, Miinster, — CONCHIFERA. 455 Type, C. Hibernicum, Pl. XIX., Fig. 6. OC. aliforme, Fig. 254. Shell, equivalve trigonal, conical and gaping infront, truncated behind, with a long siphonal tube near the umbones; anterior Fig, 254. Conocardium aliforme, Sby. 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 (Fig. 253) the large gape (a) will be for the foot, and the long tube (s) siphonal. C. Hibernicum has an expanded keel, ike Hemicardiwm inversum. 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 Aviculude. In Cardium the outer layer is only corrugated or obscurely pris- matic-cellular. Fossil, 30 species. U. Silurian — Carb. North America, Europe. Famity XI.—Lvucrinipé. 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 Lucinide 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. Fig. 255 represents the animal of a species of Diplodonta, 456 MANUAL OF THE MOLLUSCA. from the Philippines, as seen on remoying the left valve, and part of the mantle within the pallial line; b-c, the large pedal — opening; the arrows indicate — the small plain incurrent orifice, and the valvular excwrrent ori- fice; f, the foot, contracted in spirit; pp, the large striated . palpi; 7, 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. Lucina, Bruguiére. Etymology, Lucina, a name of Juno. Type, Lu. Pennsylvanica, Pl. XTX., 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 Zucina is often twice as long as the animal, but is usually folded back on itself and concealed between the gills ; it is hollow throughout. JL. lJactea (Loripes, Poli.) has a long contractile anal tube. J. tigrina (Codakia, Scop.) has the liga- ment concealed between the valves, its lateral teeth are obsolete. Distribution, 70 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, @ryptodon, Turton. L. flexuosa, Pl. XIX, Fig. 7. Synonyms, Ptychina, Phil. Thyatira, Leach. Clausina. (ferruginosa) Jeffr. Shell thin, edentulous; ligament quite in- ternal, oblique. Animal with a long anal tube. Distribution, 5 species. Norway — New Zealand. /ossil, 2 species, Hocene —. United States, Europe. Psathura, Deshayes. Anterior adductor scar long, narrow; hinge-teeth 2.2; umbones imperceptible. , CONCHIFERA. 457 Corsis, Cuvier, Etymology, corbis, a basket. Type, C. elegans. Pl. XIX, Fig. 8. Synonyms, Fimbria, Muhl. not Bohadsch. « Tdotzea,”’ Schum. Shell oval, yentricose, sub-equilateral, concentrically sculp- tured ; margins denticulated within; hinge-teeth 2, laterals 2, in each yalve ; pallial line simple ; umbonal area with an oblique furrow, 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, 5 species. India, China, North Australia, Pacific. Fossil, 80 species (including sub-genera). Lias—. United States, Europe. In @. dubia (Semi-corbis) Desh., from the LHocene, Paris, the lateral teeth are obsolete. Sub-genera. Sphera (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 Spheera, 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. Jossi/, 40 species? Lias — Portlandian. Europe. ? TANOREDIA, Lycett, 1850- _ Dedicated to Sir Thomas Tancred, Bart., founder of the Cotteswold Naturalists’ Club. Example, T. extensa, L. Pl. XXI., Fig. 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. ¢ x 458 MANUAL OF THE MOLLUSCA. DreLopontTa, Bronn. : Etymology, diplos, twin, odonta, teetn. ; Synonym, Spheerella, Conrad. k Type, D. lupinus (Venus) Brocchi. Pl. XTX., Fig. 9. ; Shell sub-orbicular, smooth; lgament double, rather long, sub-marginal; hinge-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, Rio, Britain, Medi- terranean, Red Sea, West Africa, India, Corea, Australia, Cali- fornia. D. diaphana (Felania, Recluz) 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, Pl. XIX., Fig. 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. Jossii, 1 species. Tertiary, Hurope. Unevutina, Daudin. Etymology, ungulina, like a hoof. Type, U. Oblonga. Pl. XTX., Fig. 10. Shell sub-orbicular; ligament very short; epidermis thick, wrinkled, sometimes black; hinge-teeth 2.2; muscular im- pressions long, rugose. q 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, : | | CONCHIFERA. 459 KELLIA, Turton, 1822. Etymology, named after Mr. O'Kelly, of Dublin. Synonyms, Lasea (Leach), Br. 1827. Cycladina (Adansonii) Cantr. Bornia (sub-orbicularis) Phil. Poronia (rubra), Recluz (not Willd). Erycina (cycladiformis), Desh. (not Lam.) Types, K. sub-orbicularis, Mont. K. rubra. Pl. XIX.,, Fig. 12. Shell small, thin, sub-orbicular, closed ; beaks small; margins smooth; ligament internal, interrupting the margin (in K. suborbicularis), or on the thickened margins (in K. rubra) ; cardinal teeth 1 or 2, laterals 1—1 in each valve. Animal with the mantle prolonged in front into a respiratory canal, either complete (in K. suborbicularis) or opening into the pedal slit (in K. 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 byssus at pleasure. . sbra is found in crevices of rocks at high-water mark, and oftcn in situations only reached by the spray, except at spring-tides; other species range as deep as 200 fathoms. K. Laperousti (Chironia), Desh. Pl. X1TX., 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. (Myllita, D’Orb, and Recl.). Shell trigonal, divaricately sculptured ; igament internal; right valve with 2 lateral teeth, left-with 1 cardinal and 2 laterals, Distribution, 8 species, New Ireland, Australia,- Philippines, Fossil, 2 species, Hocene—, France, Jaya. x 2 460 MANUAL OF THE MOLLUSCA. Montacura, Turton. Dedicated to Colonel George Montagu, the most distinguished of the earlier English malacologists. Type, M. substriata. Pl. XIX., Fig. 13. Shell minute, thin, oblong, anterior side longest; hinge-line notched ; ligament internal, between 2 laminar, diverging teeth (with a minute ossicle. Lovén.) Animaé with the mantle open in front; margins simple ; siphonal orifice single; foot large and broad, grooved. The Montacute moor themselves by a byssus, or walk freely ; M. substriata has only been found attached to the spines of the purple heart-urchin (Spatangus purpureus) in 5—90 fathoms. M. bidentata burrows in the valves of dead oyster-shells. Distribution, 3 species. United States, Norway, Britain, Aigean. Fossil, 2 species. Pliocene—. Britain. LzEpton, Turton. Etymology, lepton, a minute piece of money (from leptos, thin). Synonym ? Solecardia (eburnea), Conrad, Lower California. Type, L. squaamosum. Pl. 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) open in front, extending beyond the shell, and bearing a fringe of filaments, of which one in front (¢) 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 (Cumingi), Desh. 1856. Small shells resembling JLepton; 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. CONCHIFERA. 461 GaLEomMA, Turton. Synonyms, Hiatella, Costa (not Daud.) ; Parthenopea, Scacchi {not Fabr). Type, G. Turtoni, Pl. XIX., Fig. 15. (Galee, weasel, omma, eye.) Shell thin, oval, equilateral, gaping widely below; invested with a thick, fibrous epidermis; beaks minute; lgament 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 Galeomma 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. Pliocene—. . Sicily. Famity XII.—CycLaDIDzA, 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 Cyclas, a name now retained for the small species inha- biting the rivers of the north temperate zone; the Cyrene 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. Cycias, Bruguiére. Etymology, kuklas, orbicular. Type, C. Cornea. Pl. XIX., Fig. 17. Synonyms, Spherium, Scop. Pisum, Muhlf. (not L.) Mus- eulium, Link. x 462 MANUAL OF THE MOLLUSCA. = Shell thin, ventricose, nearly equilateral; cardinal teeth 2.1, minute, laterals 1—1: 2—2, elongated, compressed. Animal eyo-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 internal branchiee, they are few in number and very unequal in size; a full-grown CO. cornea has about 6 in each gill; the largest being 4 to + the length of the parent. The young Cyclades and Pisidia are yery active, climbing about submerged plants and often suspending themselves by byssal threads; the striated gills and pulsating heart are easily seen through the shell. Fig. 257. Pisidium amnicum, %, with its foot protruded, Sub-genera, Pisidium, Pfr. P. amnicum, Pl. 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 confluent. Distribution, 60 species. United States, South America, Greenland, Norway, Sicily, Algeria, Cape, India, Caspian, Britain. Fossil, 38 species. Wealden—. Europe. CyrEnaA, Lamarck. Etymology, Cyrene, a nymph. Type, C. cyprinoides, Pl. XIX., Fig. 20. Shell oval, strong, covered with thick, rough epidermis; ligament thick and prominent; hinge-teeth 3.3, laterals 1—1 in each yalye; pallial line shghtly 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. CC. consobrina, Pl. XIX., Fig. 21. Shell orbicular, concentrically furrowed, epiderrnis — polished ; lateral teeth elongated, striated across. CONCHIFERA. 4638 Batissa, Gray. Anterior lateral teeth short; under 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. consobrina ranges from Egypt to Cashmere and China, and is found fossil in the Pliocene formations of England,* Belgium, and Sicily. Fossil, 104 species. Wealden—. LEurove, United States. ? CYRENOIDES, Joannis. Synonym, Cyrenella, Desh, Type, C. Dupontiu, Pl. XTX., Fig. 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; palliai 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. River Senegal. The marine species are Diplodonte. Fossil, 1 species. Europe. Famity XIIIT.—Cyprinipvz#. 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. Cyprina, Lamarck. Etymology, Kuprinos (from Kupris), related to Venus. Type, C. Islandica, Pl. XIX., Fig. 22. * Associated with the bones of Elephas meridionalis, Rhinoceros leptorhinus, MM :stodon Arvernensis, Hippopotamus major, §c. 464 MANUAL OF THE MOLLUSCA, Synonym, Arctica, Schum. Shell oval, large and strong, with usually an oblique line or angle on the posterior side of each valve; epidermis thick and dark; lgament prominent, umbones oblique; no lunule; cardinal teeth 2.2, laterals 0—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 gitls 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. Fossil, 90 species. (D’Orbigny.) Muschelkalk—. Europe, CrrcE, Schumacher. Etymology, in Greek mythology a celebrated enchantress. Hzample, C. corrugata, Pl. XX., Fig. 2. Synonym, Paphia (undulata), Lamarck.* Shell sub-orbicular, compressed, thick, often sculptured with diverging strie; umbones flat; lunule distinct; lgament 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, Ranges from 8—50 fathoms. (Forbes.) Distribution, 40 species. Australia, India, Red Sea, Canaries, — Britain. ; AsTArTE, Sowerby, 1816. Synonym, Crassina, Lamarck. Tridonta, Schum. Goodallia, Turton. EHxample, A. suleata, Pl. XX., Fig. 1. A. borealis, Fig. 258. (Astarte, the Syrian Venus.) Shel/ sub-orbicular, compressed, thick, smooth or concen- * This name was employed by Bolten, in 1798, for sp. of Veneride, and by Lamarck, in 1801, for Venus divaricata, Chemn. (== 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, having been abandoned by Lamarck in his later works, and by all succeeding malacologists, CONCHIFERA. 465 trically furrowed ; lunule impressed; ligament external; epi- dermis dark; hinge-teeth 2.2, the anterior tooth of the right valve large and thick ; anterior pedal scar distinct ; pallial line sunple. Animal with 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 of Astarte borealis 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 borealis, 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, Mgean (30—112 fathoms). Fossil, 285 species. Carb. —. North and South America, Europe, Thibet. > ? Digitaria, Wood; Tellina digitaria, Lower Mediterranean. Fossil, Pliocene, Britain. Govxp1A, C. B. Adams. Shell minute, triangular, furrowed: hinge like Astarte, with lateral teeth; pallial line simple. Distribution, 7 species. Panama, West Indies. x3 466 MANUAL OF THE MOLLUSCAs CRASSATELLA, Lamarck. Synonyms, Ptychomya, Ag, Paphia (Lamarck, part) Roissy. Type, C. ponderosa, Pl. XXI., Fig. 4. C. pulchra, Fig. 259. Etymology, crassus, thick. Shell solid, ventricose, 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 0O—1, 1—0; adductor impressions deep, 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, Sandy Cape, J. B. Jukes. Animal as seen oft the removal of riyht valve, and portion of the mantle, In Crassatella pulchra the animal is like Astarte ; foot lingtii- form, slightly grooved; palpi short and broad, few-plaited ; outer gill narrower in front. HS . Distribution, 34 species. Australia, New Zealand, Philippines, India, West Africa, Canaries, Brazil. i Fossil, 64. species. Neocomian —. Patagonia, United States, Europe. Tsocarpi1A, Lamarck. Heart-cockle. Etymology, isos, like, cardia, the heart. Type, 1. cor, Pl. XX., Fig. 3. CONCHIFERA. 467 Synonyms, Glossus, Poli; Bucardium, Muhlfeldt; Pecchiolia, Meneghini. Shell cordate, ventricose; umbones distant, sub-spiral; ligament external ; hinge-teeth 2.2 ; laterals 1—1 in each yalve, 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 /secardta cor. The heart-cockle burrows in sand, by means of its foot (/), leaying 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 Jso-arca ; many of those in the Oolites to Ceromya. Casts of true Isocardie have only two transverse dental folds between the beaks, and no longitudinal furrows. CyPrRICARDIA, Lamarck. Example, C. obesa, Pl. XX., Fig. 4. C. rostrata, Fig. 261. Synonyms, 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 MANUAL OF THE MOLLUSCA. 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 smail; gills unequal, the outer narrower and shorter, deeply lamellated, united posteriorly, the inner prolonged between the palpi. Animal of Cypricardia rostrata, Lamarck, Philippines (Fig. DP 300), with mantle-lobes united, — and covered with wrinkled epi- a dermis ; siphonal orifices fringed; %\\2- gills deeply plicated, anterior )) part of the outer gill united to the inner ; dorsal border narrow, plaited ; adductor muscles of two elements, Distribution, 18 species. Red Sea, India, and Australia. In crevices of rock and coral. Fossil, 60 species. Lower Silurian —. North America and Europe. ? Sub-genera. Coralliophaga, Bl. OC. coralliophaga, Lamarck. Shell long, cylindrical, thin, shghtly gaping behind; hinge- teeth 2.2, and a laminar posterior tooth; pallial line with a wide and shallow sinus. Distribution, 5 species. Mediterranean, in 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. Rep., 1841. (San-~ guinolites, M‘Coy.) Employed for Cypricardia-shaped shells of the paleeozoic rocks; some of them are more nearly related to Modiola (vy. Modiolopsis, p. 422), but they bear no resemblance to Sanguinolaria. Goniophora, Phillips, 1848. Cypricardia cymbeeformis, Sby. Upper Silurian, Britain (Mytilide ?). Fig. 261. Cypricardia. PLEUROPHORUS, King, 1848. Type, P. costatus, Brown. Permian, England. (Pal. Trans., 1850. Pl. XV., Figs. 13—20.) Synonyms ? Oleidophorus, Hall (cast only). Unionites, Wissm. ? Meeonia, Dana. Shell oblong ; dorsal area defined by a line, or keel; umbones anterior, depressed; hinge-teeth 2.2; laterals 1.1; elongated posterior ; anterior adductor impression deep, witha small pedal — scar close to it, and bounded posteriorly by a strong rib from the hinge; pallial line simple. CONCHIFERA. 469 ? Sub-genus. Redonia, Rouault, Bull Soc. Geol., 8, 362. Shell oval, tumid; hinge with cardinal and posterior teeth ; anterior adductor bounded bya ridge. /ossi/, Lower Silurian, Brittany, Portugal. (Sharpe.) Fossil, 5 species. Lower Silurian—Trias. United States, Europe, New South Wales, Tasmania. ? CARDILIA, Deshayes. Type, C. semisuleata, Pl. X VIII., Fig. 18. Synonym, Hemicyclonosta, Deshayes. Shell oblong, ventricose, cordate; beaks prominent, sub- spiral; hinge with a small tooth and dental pit in each valve; ligament partly internal contained in a spoon-shaped inflection ; anterior muscular scar long, with a pedal scar above; posterior adductor impression on a prominent sub-spiral plate; pallial line simple. Distribution, 2 species. Chinese Sea, Moluccas. Fossil, 2 species. Hocene—. France, Piedmont, MEGALODON, J. Sowerby. Type, M. cucullatus, Pl. XIX., Fig. 19. (Megas, large, odous, tooth. ) Shell oblong, smooth or keeled; ligament external; hinge- teeth 1.2, thick; laterals 1.1, posterior; anterior adductor impression deep, with a raised margin, and a small pedal scar behind it. In the typical species the beaks are sub-spiral, the lateral teeth obscure, and the posterior adductors bounded by prominent ridges. . Fossil, 14 species. Upper Silurian—Devonian. United States, Europe. Sub-genera. ? Goldfussia (nautiloides), Castlenau. Umbones spiral; anterior side concentrically furrowed; posterior side with two oblique ridges. /ossil, Silurian, United States. Megaloma (Canadensis), Hall, 1852. Upper Silurian, Canada. Umbones very thick, hinge-teeth rugged, almost obliterated with age; posterior lateral teeth 1.1; no muscular ridges. PAcHyDomvs (Morris), J. Sowerby. Etymology, pachus, thick, domos, house. Synonyms, Astartila, Dana. ? Cleobis (grandis), Dana. P Pyramus (ellipticus), D. =Notomya, M‘Coy. 470 MANUAL OF THE MOLLUSCA, Type, P. globosus (Megadesmus), J. Sowerby, in Mitchell’s Australa. Shell oval, ventricose, very thick; ligament large, external ; lunette more or less distinct; hinge-line sunk; teeth 1 or 2 (?) in each valve ; adductor impressions deep; anterior pedal scar distinct ; pallial line broad and simple, or with a very shallow sinus. Fossil, 6 species. Devonian? New South Wales, Tasmania. PacHYRISMA, Morris and Lycett. Etymology, pachus, thick, ereisma, support. Type, P. grande, Morrisand Lycett. Great Oolite (Bathonian), Minchinhampton. Shell cordate, with large sub-spiral beaks ; valves very thick near the umbones, obliquely keeled; hinge with one thick conical tooth (behind the dental pit, in the right valve), a small lateral tooth close to the deep and oval anterior adductor, and a posterior lateral-tooth (or muscular lamina ?) ; ligamental plates short and deep. Opis, Defrance. Example, O. lunulata, Pl. XIX., Fig. 24. (Opis, a name of Artemis.) Shell strong, ventricose, cordiform, obliquely keeled; beaks prominent, incurved, or sub-spiral; cardinal teeth 1.1; lunule distinct. Fossil, 42 species, Trias—Chalk. Europe. CARDINIA, Agassiz, Etymology, cardo-inis, a hinge. Type, C. Listeri, Pl. XLX., Fig. 23. Synonyms, Thalassides, Berger, 1833 (no description). Sine- muria, Christol. Pachyodon, Stutch. (not Meyer nor Schum), Pronoe, Agassiz. Shell oval or oblong, attenuated posteriorly, compressed, — strong, not pearly, marked by lines of growth; lgament external; cardinal teeth obscure, laterals 1—0, 0—1, remote, prominent; adductor impressions deep; pallial line simple. Fossil, 71 species. Silurian—Inferior Oolite. Europe; along with marine shells. | Sub-gerus P Anthracosia, King, 1844; Unio sub-constrictus, Sowerby. (Carbonicola, M‘Coy, 1856.) Upper Silurian—Carb. 40 species. They occur in the valuable layers of clay-ironstone called ‘‘mussel-bands,” associated with Nautili, Discine, &c. CONCHIFERA. 471 In Derbyshire the mussel-band is wrought, like marble, into Vases. ? Myoconcua, J. Sowerby. Type, M. crassa, Pl. XIX., Fig. 25. (Mya, mussel, concha, shell.) Shell oblong, thick, with nearly terminal depressed umbones ; ligament external, supported by long, narrow, appressed plates ; hinge thick, with an oblique tooth in the right valve; anterior muscular impression round and deep, with a small pedal scar behind it; posterior impression large, single; pallial line simple. This shell, which is not nacreous inside, is distinguished from any of the Mytilide by the form of its ligamental plates and muscular impressions; the hinge-tooth is usually overgrown and nearly obliterated by the hinge-margin, asin aged examples , of Cardita orbicularis and Cypricardia vellicata. Fossil, 26 species. Permian—Miocene. (D’Orb.) Europe. Sub-genus. ? Hippopodium (ponderosum, Sowerby), Coneybeare. Lias, Europe. Shell oblong, thick, ventricose ; umbones large ; ligament external; ventral margin sinuated; hinge with one thick, oblique tooth in each valve, sometimes nearly obsolete ; pallial line simple; anterior muscular scar deep. This shell appears to be a ponderous form of Cypricardia or Cardita ; it is a characteristic fossil of the English Lias, but only very aged examples have been found. CARDITA, Bruguiére. Synonyms, Mytilicardia and Cardiocardita (ajar), Bl. Arcinella, Oken. Type, C. calyculata, Pl. XX., Fig. 5. Etymology, cardia, the heart. Shell oblong, radiately ribbed; ligament external; margins toothed; hinge-teeth 1.2, and an elongated posterior tooth; pallial line simple; anterior pedal scar close to adductor. Animal with the mantle-lobes free, except between the siphonal orifices; branchial margin with conspicuous cirri: foot rounded and grooved, spinning a byssus; labial palpi short, triangular, plaited ; gills rounded in front, tapering behind, and united together, the outer pair narrowest. C. pectunculus, Bruguiére, (Mytilicardia, Blainville), has an anterior tooth. C. concamerata, Bruguiére, found at the Cape, has a remarkable cup-like inflection of the ventral margin ot each valve. 472 MANUAL OF THE MOLLUSCA. Sub-genus. Venericardia, Lamarck. V. ajar, Pl. XX., Fig. 6. Shell cordate, ventricose ; hinge without lateral teeth. Animal locomotive, with a sickle-shaped foot like the cockles. Distribution, 54 species. Chiefly in tropical seas, on rocky bottoms and in shallow water; the Venericardice on coarse sand and sandy mud. West Indies, United States, West Africa, Mediterranean, Red Sea, India, China, Australia, New Zealand, Pacific, West America. (. borealis, Conrad, inhabits the sea of Ochotsk; ©. abyssicola, Hinds, ranges to 100 fathoms; C. squamosa, to 150 fathoms. Fossil, 170 species. Trias—. United States, Patagonia Europe, Southern India. P VERTICORDIA, Searles Wood, 1844. Synonyms, Hippagus, Philippi, not Lea. Trigonulina, D’Orb. ,(Verticordia, a name of Venus.) Type, V. cardiiformis (Wood, in Sby. Min. Con.), Pl. XVII, Vig. 26. Shell sub-orbicular, with radiating ribs; beaks sub-spiral; margins denticulated; interior brilliantly pearly ; right valve with 1 prominent cardinal tooth; adductor scars 2, faint; pallial line simple; ligament internal, oblique; epidermis dark brown. Distribution, 2 species. China Sea (Adams); Mediterranean? (Forbes. ) : Fossil, 2 species. Miocene—. Britain, Sicily. Hippagus isocardioides, Lea, 1833, Eocene, Alabama, is eden- tulous. Trigonulina ornata, D’Orbigny, Jamaica, has hinge- teeth 2.2; right valve with along posterior tooth. Epidermis of large nucleated cells, as in Z'rigoniade, to which family it undoubtedly belong SECTION b,—SINU-PALLIALIA. Respiratory siphons long ; pallial line sinuated. FamMIty XIV.—VENERIDA. Shell regular, closed, sub-orbicular, or oblong ; ligament external ; hinge with usually 3 diverging teeth in each valve ; muscular i impressions oval, polished ; pallial line sinuated. Animal free, locomotive, rarely byssiferous or burrowing ; mantle with a rather large anterior opening ; siphons unequal, united more or less; foot linguiform, compressed, sometimes grooved; palpi moderate, triangular, pointed ; branchize Rate sub-quadrate, united posteriorly. — CONCHIFERA. 473 The shells of this tribe are remarkable for the elegance of their forms and colours; they are frequently ornamented with cheyron-shaped lines. Their texture is very hard, all traces of structure being usually obliterated. The Veneride appeared first in the Oolitic period, and have attained their greatest develop- ment at the present time; they are found in all seas, but most abundantly in the tropics, Venus, L. Synonyms, Merceneria, Antigone, and Anomalocardia (flexuosa) Schum, Chione, Megerle (not Scop.). Erycina (carioides), Lamarck, 1818. Type, V. paphia, L. Pl. XX., Fig. 7. Shell thick, ovate, smooth, sulcated, or cancellated ; margins minutely crenulated; cardinal teeth 3—3; pallial sinus small, angular; ligament prominent; lunule distinct. Animal with mantle-margins fringed ; siphons unequal, more or less separate; branchial orifice sometimes doubly fringed, the outer pinnate; anal orifice with a simple fringe and tubular valve; foot tongue-shaped; palpi small, lanceolate. V. textilis, and other elongated species, have a deep pallial sinus; V. gemma (Totten) has a very deep angular sinus, like Artemis ; V. reticulata has bifid teeth, like Tapes; V. tridac- noides, a fossil of the United States, has massive valves, ribbed like the clam-shell. The North American Indians used to make coinage (wampum) of the sea-worn fragments of Venus mercenaria, by perforating and stringing them on leather thongs. Distribution, 176 species. World-wide... Low water—140 fathoms. V. astartoides, Behrings’ Sea. V. verrucosa, Britain, Mediterranean, Senegal, Cape, Red Sea: Australia ? Fossil, 200 species. Oolites—. Patagonia, United States, Europe, India. ? Volupia rugosa. (Defrance, 1829.) Shell minute, Isocardia- shaped, concentrically ribbed, with a large lunule. ocene, Hauteville. Saxidomus (Nuttalli), Conrad. Oval, solid, with tumid um- bones; lunule 0; teeth 3—4, unequal, the central bifid; pallial sinus large. Distribution, 8 species. India, Australia, West America. CYTHEREA, Lam. Etymology, Cytherea, from Cythera, an Aigean island. 474 MANUAL OF THE MOLLUSCA. Synonyms, Meretrix, Gray. Dione, Megerle, Cryptogramma, Morch. Examples, C. dione, Pl. XX., Fig. 8. ©. chione, Fig. 14, p- 26. Shell like Venus; margins simple; hinge with 3 cardinal teeth and an anterior tooth beneath the lunule; pallial sinus moderate, angular. , Animal with plain mantle-margins ; siphons united half-way. Distribution, same as Venus. Recent 113 species, Fossil, 80 species. ; MEROE, Schum. 8 Etymology, Meroé, an island of the Nile. Synonyms, Cuneus (part) Megerle (not Da Costa). Sunetta, Link. Type, M. picta (=Venus Meroé, L. Donax, Deshayes). Ph Xk, Wizs9. Shell oval, compressed; anterior side rather longest; hinge with 8 cardinal teeth, and a long narrow anterior tooth; lunule lanceolate ; ligament in a deep escutcheon. Distribution, 11 species. Senegal, India, Japan, Australia. Tricona, Miuhlfeldt. Etymology, trigonos, three-cornered. Type, T. tripla, Pl. XX., Fig. 10. _ Shell trigonal, wedge-shaped, sub-equilateral; ligament short, prominent; cardinal teeth 3—4, anterior ? remote; pallial sinus rounded, horizontal. Distribution, 28 species. West Indies, Mediterranean, Senegal, Cape, India, West America. Fossil, Miocene—. Bordeaux. T. crassatelloides attains a diameter of 5 inches, and is very ponderous. Sub-genus, Grateloupia, Desm. G. irregularis, Pl. XX., Fig. 11. Shell sub-equilateral, rounded in front, attenuated behind ; hinge with 1 anterior tooth, 3 cardinal teeth, and several small posterior teeth; pallial sinus deep, oblique. fossil, 4 species. Eocene—Miocene. United States, France. ARTEMIS, Poli. Etymology, Artemis, in Greek mythology Diana, Type, A. exoleta, Pl. XX., Fig. 12, Synonym, Dosinia, Scopoli, CONCHIFERA. 475 Shell orbicular, compressed, concentrically striated, pale ligament sunk; lunule deep; hinge lke Cytherea; margins even; pallial sinus deep, angular, ascending. Animal with a large hatchet-shaped foot, projecting from the ventral margin of the shell ;,mantle-margins slightly plaited ; siphons united to their ends; ofifiges simple ; palpi narrow. Distribution, 100 species. Boreal—Tropical seas; low water 80 fathoms. Fossil, 13 species. Carb—. United States, Europe, South India. Sub-genera. Cyclina, Desh. Y. Sinensis, Chemn. Orbicular, ventricose, margins crenulated, no lunule, sinus deep and angular. Distribution, 10 species, Senegal, India, China, Japan, West America. J ossil, 1 species. Miocene, Bordeaux. Clementia (papyracea) Gray. Thin, oval, white; lgament semi-internal; posterior teeth bifid, sinus deep and angular. Animal with long, united siphons, and a large crescentic foot, similar to Artemis. Distribution, 6 species. Australia, Philip- pines. Luctnopsis, Forbes. Synonyms, Dosinia, Gray, 1847 (not Scop.). Mysia, Gray, 1851 (not Leach). Cyclina, Gray, 1853 (not Desh.). Type, Venus undata, Pennant, Pl. XX., Fig, 13. (Lucine and opsis like.) Shell lenticular, rather thin; right valve with 2 laminar, diverging teeth, left with 3 teeth, the central bifid; muscular impressions oval, polished ; pallial sinus very deep, ascending. Animal with mantle-margins plain; pedal opening con- tracted ; foot pointed, basal; siphons longer than the shell, separate, divergent, with fringed orifices. (Clark.) The type of this genus having been erroneously placed in Cyclina by M. Deshayes, he has proposed a new genus (Lajon- kairia) for LZ. decussata, Philippines, a fossil of the English Pliocene, but still livimg in the Mediterranean. Distribution, 10 species. North America, Norway, Britain. Fossil, 8 species. Pliocene. Britain, Belgium. Tapes, Mihlfeldt. Synonyms, Paphia, Bolten, 1798. Pullastra,G. Sby. Omalia, _Ryck, 1856. Example, T. pullastra, Pl. XX., Fig. 14. (Tapes, tapestry.) Shell oblong, umbones anterior, margins smooth; teeth 3 in each yalye, more or less bifid; pallial sinus deep, rounded, 476 MANUAL OF THE MOLLUSCA. Animal spinning a byssus; foot thick, lanceolate, grooved ; mantle plain or finely fringed; freely open in front; siphons moderate, separate half-way or throughout, orifices fringed, anal cirri simple, branchial ramose; palpi long, triangular. Distribution, 78 species. Norway, Britain, Black Sea, Senegal, Brazil, India, China, New Zealand. ow water—100 fathoms. (Beechy.) Fossil, 6 species. Pliocene—. Britain, France, Belgium, Italy. The animal is eaten on the continental coasts; it buries in the sand at low water, or hides in the crevices of rocks, and roots of sea-weed. VENERUPIS, Lamarck. Etymology, Venus, and rupes, a rock. Synonym, Gastrana, Schum. Hxzample, V. exotica, Pl. XX., Fig. 15. Shell oblong, a little gaping posteriorly, radiately striated and ornamented with concentric lamellz; three small teeth in each valve; one of them bifid; pallial sinus moderately deep, angular. Animal with the mantle closed in front, pedal opening mode- rate; siphons united half-way, and with a simple fringe and tubular valve, branchial siphon doubly fringed, imner cirri branching; palpi small and pointed. Distribution, 19 species. Britain—Crimea; Canaries, India, Tasmania, Kamtschatka, Behring’s Straits—Peru. In crevices of rocks. Fossil, Miocene—. United States, Europe. PETRICOLA, Lamarck. Litymology, petra, stone, colo, to inhabit. Synonyms, Rupellaria, Bellevue; Choristodon, Jonas; Na- ranio, Gray. Type, P. lithophaga, Pl. XX.,,Fig. 16. P. pholadiformis, Pl. Bok Pigi 17. Shell oval or elongated, thin, tumid, anterior side short; hinge with 3 teeth in each valve, the external often obsolete ; pallial sinus deep. Animal with the mantle closed in front, much thickened and recurved over the edges of the shell; pedal opening small ; foot small, pointed, lanceolate; siphons partially separate, orifices fringed, anal with a valve and simple cirri, branchial cirri pinnate ; palpi small, triangular. CONCHIFERA. 477 Distribution, 30 species. United States, France, Red Sea, India, New Zealand, Pacific, West America (Sitka—Peru). Burrows i in limestone and mud. Fossil, 20 species. Hocene—. United States, Europe. GrAucoMyA (Bronn), Gray. Synonym, Glauconome, Gray, 1829 (not Goldfuss, 1826). Type, G. Sinensis, Pl. XX., Fig. 18. (Glaucos, sea-green, mya, mussel.) Shell oblong, thin; epidermis dark, greenish; ligament ex- ternal; hinge with 3 teeth in each valve, one of them bifid; pallial sinus very deep and angular. Animal with a rather small, linguiform foot; pedal opening moderate ; siphons very long, united, projecting far into the branchial cavity when retracted, their ends separate and diverg- ing; palpi large, sickle-shaped; gills long, rounded in front, the outer shortest. Sub-genus. Tarysiphon, Benson. Differs from Glancomya in haying the siphons united up to the end. Distribution, 12 species. Embouchures of rivers; China, Philippines, Borneo, India. Fossil, 2 species. Tertiary. Europe. FaMIty XV.—MAcTRIDA. Shell equivalye, trigonal, close, or slightly gaping; ligament (cartilage) internal, sometimes external, contained in a deep triangular pit; epidermis thick; hinge with 2 diverging car- dinal teeth, and usually with anterior and posterior laterals ; pallial sinus short, rounded. Animal with the mantle more or less open in front ; siphonal tubes united, orifices fringed; foot compressed; gills not pro- longed into the branchial siphon. Sections of the shell exhibit an indistinct cellular layer on the external surface and a distinct layer of elongated shell. (Car- penter. ) MactTra, L. Etymology, mactra, a kneading trough. Synonyms, Trigonella, Da Costa (not L.), Schizodesma (Spengleri), Spisula (solida), Mulinia (lateralis), Gray. Type, M. stultorum, Pl. XX1I., Fig. 1. _ Shell nearly equilateral; anterior hinge-tooth A-shaped, with 478 MANUAL OF THE MOLILUSCA. sometimes a small laminar tooth close to it; lateral teeth doubled in the right valve. Animal with the mantle open as. far as the siphons, its margins fringed; siphons united, fringed with simple cirri, anal, orifice with a tubular valve; foot large, linguiform, heeled ; palpi triangular, long, and pointed; outer gills shortest. The Mactras inhabit sandy coasts, where they bury just beneath the surface ; the foot can be stretched out considerably, and moyed about like a finger, it is also used for leaping. They are eaten by the star-fishes and whelks, and in the Isle of Arran M. subtruncata is collected at low water to feed pigs. (Alder.) Distribution, 125 species. All seas, especially within the tropics ;—35 fathoms. Fossil, 30 species. Lias—. United States, Europe, India. ?, Sub-genera. Sowerbya, D’Orb. Isodonta, Buy. S&S. crassa, Oxfordian, France. Cartilage-pit simply grooved; it receives a tooth of the opposite valve ; lateral teeth very large. HARVELLA, Gray. Lateral teeth small; shell cordate; thin; truncated pos- teriorly, and obliquely striated ; hi cumont external, separated from the cartilage in the inner pit by a ridge; hinge teeth small. Sub-genus, Mactrella, Gray. Mactrinula, Gray. Shell cor- date, abruptly truncated behind; lateral teeth short. GNATHODON, Gray. Etymology, gnathos, a jaw-bone, odus, a tooth. Synonym, Rangia, Desm. Type, G. cuneatus, Pl. XX1., Fig. 2 Shell oval, ventricose; valves thick, smooth, eroded ; epider- mis olive; cartilage-pit central; hinge-teeth ?; laterals doubled in the right valve, elongated, striated transver aly pallial sinus moderate. Animal with the mantle freely open in front ; margins plain ; siphons short, partly united ; foot very thick, tongue-shaped, pointed; gills unequal, the outer short and narrow; palpi large, triangular, pointed. Distribution, 1 species. New Orleans. (2% other species ? ial zatlan, California; Moreton B. Australia. Petit.) Fossil, 3 species. Chalk—. Petersburg, Virginia, CONCHIFERA. 479 G. cuneatus was formally eaten by the Indians. At Mobile, on the Gulf of Mexico, it is found in colonies along with Cyrena Carolinensis, burrowing 2 inches deep in banks of mud; the water is only brackish, though there is a tide of 3 feet. Banks of dead shells, 3 or 4 feet thick, are found 20 miles inland: Mobile is built on one of these shell-banks. The road from New Orleans to Lake Pont-chartrain (6 miles) is made of Gnathodon shells procured from the east end of the lake, where there is a mound of them a mile long, 15 feet high, and 20—60 yards wide ; in some places it is 20 feet above the level of the lake. (Lyell. ) LUTRARIA, Lamarck, Otter’s-shell. Type, L. oblonga, Gmel. Pl. XXI., Fig. 3. (= L. solenoides, Lamarck). Shell oblong, gaping at both ends; cartilage-plate prominent, with 1 or 2 small teeth in front of it, in each valve; pallial sinus deep, horizontal. Animal with closed mantle-lobes ; pedal opening moderate ; foot rather large, compressed; siphons united, elongated, in- vested with epidermis; palpi rather narrow, their margins plain ; gills tapering to the mouth. Distribution, 18 species. United States, Brazil, Britain, Medi- terranean, Senegal, Cape, India, New Zealand, Sitka. Fossil, 25 species. Carb.--. United States, Europe. Resembles Mya; burying vertically in sand or mud, especially of estuaries; low water, 12 fathoms. JZ. rugosa, found lying on the coasts of Portugal and Mogador, is fossil on the coast of Sussex. (Dixon.) Sub-genus, Vaganella, Gray. Mantle sinus, large, round; interior ridges, of which two diverge Mowe the hinge to the ventral edge. ANATINELLA, G, Rll Type, A. candida, (Mya) Chemn. Pl. XXIII., Fig. 6. Shell ovate, rounded in front, attenuated and truncated be- hind ; cartilage in a prominent spoon-shaped process, with 2 small teeth in front; muscular impressions irregular, the anterior elongated; pallial line slightly: truncated behind. Distribution, 8 species. Ceylon, Philippines; sands at low ‘water. Famity XVI.—TELLINIDE. Shell free, compressed, usually closed and equivalye ; cardinal teeth 2 at most, laterals 1—1, sometimes obsolete; muscular 480 MANUAL OF THE MOLLUSCA. impressions rounded, polished; pallial sinus very large; liga- . ment on shortest side of the shell, sometimes internal. Struc- ture obscurely prismatic-cellular; prisms fusiform, nearly . parallel with surface, radiating from the hinge in the outer layer, transverse in the inner. Animal with the mantle widely open in front, 1ts margins fringed ; foot tongue-shaped, compressed; siphons separate, very long and slender; palpi large, triangular; gills united posteriorly, unequal, the outer pair sometimes directed dorsally. The Tellens are found in all seas, chiefly in the littoral and ~ laminarian zones; they frequent sandy bottoms, or sandy mud, burying beneath the surface; a few species inhabit estuaries and rivers. Their valves are often richly coloured and orna- mented with finely sculptured lines. TELLINA, L. Tellen. Etymology, Telline, the Greek name for a kind of mussel. Synonyms, Peroneea (part) Poli. Phylloda (foliacea), Omala {planata) Schumacher. Psammotea (solidula) Turt. Arco- pagia (crassa) Leach. Tellinodora, Morch. Examples, T. Fingua-felis, Pl. XXI., Fig. 5. TT. carnaria, Fig. 6. Shell slightly inequivalve, compressed, rounded in front, angular and slightly folded posteriorly, umbones sub-central ; teeth 2.2, laterals 1—1, most distinct in the right valve ; pallial sinus very wide and deep; ligament external, prominent. Animal with slender, diverging siphons, twice as long as the shell, their orifices plain; foot broad, pointed, compressed ; palpi very large, triangular; gills small, soft and very minutely striated, the other rudimental and directed dorsally. Tellinides, Lamarck. T. planissima, Pl. XXI., Fig. 7. Valves with no posterior fold; lateral teeth wanting. " T. carnaria (Strigilla, Turt.) has the valves obliquely sculp- tured; 7’. fabula, Gron., has the right valve striated, the other plain. 7. Burneti, California, has the right valve flat; 7’. dunu- lata, Pliocene, South Carolina, much resembling it in shape, has the left valve flat. ; Distribution, above 300 species. In all seas, especially the Indian Ocean; most abuudant and highly coloured in the tropics. Low water — Coral zone, 50 fathoms. Wellington Channel; Kara Sea; Behring’s Straits; Baltic; Black Sea. Fossil, 170 species. Oolites—. United States, South America (Chiloe), Europe. CONCHIFERA. 481 GASTRANA, Schumacher, Synonyms, Fragilia, Desh. Diodonta, F. and H., not Schu- macher. Type, Tellina fragilis, L. Pl. XXI., Fig. 8. Shell, equivalye, convex, with squamose lines of growth; cardinal teeth 2 in right valve, 1 bifid tooth in left; pallial sinus deep and rounded; umbonal area punctate ; ligament external. Animal with the mantle open in front, its margins fringed; siphons elongated, slender, separate, unequal, orifices with cirri; _ foot small, compressed, linguiform; palpi large, triangular; gills unequal, soft, finely striated. Gastrana inhabits shallow water, boring in mud and clay, and not travelling about like the Tellens. Distribution, 3 species. Norway, Britain, Mediterranean, Black Sea, Senegal, Cape. Fossil, Miocene—. Britain, France, Belgium. CapsuLs, Schumacher. Etymology, Dimin. of capsa, a box. Synonyms, Capsa (part), Brug. 1791. Sanguinolaria, Lamarck, - 1818, not 1801. Type, C. rugosa, Pl. XX., Fig. 19. (= Venus deflorata, Gmel). Shell oblong, ventricose, slightly gaping at each end ; radiately striated ; cardinal teeth 2 in each valve, one of them bifid ; liga- ment external, large, prominent; siphonal inflection short. Animal like Psammobia ; foot moderate; gills deeply plaited, attenuated in front, outer small, dorsal border wide, fixed; siphons moderate. Distribution, 4 species. West Indies, Red Sea, India, China, Australia. Fossil, 20 species. Carb. —. United States, Europe. (D’Orb.) QUENSTEDTIA, Morris and Lycett. Hinge in left valye with obtuse, oblong, transverse teeth ; pallial sinus small; ligament in a narrow groove; cardinal teeth 0.1. PSAMMOBIA, Lamarck. Sunset-shell. Etymology, psammos, sand, bio, to live. ¥ 482 MANUAL OF THE MOLLUSCA. Synonyms, Psammotea (zonalis) Lamarck. Psammocola, ae Gari, Schumacher. Fig. 262. Psammobia vespertina, Chemn, 4. Brit, Example, P. Ferroénsis, Pl. XXI., Fig. 9. P. squamosa, Pl. XXI., Fig. 10. P. pallida, Fig. 263. PP. vespertina, Fig. 262. Shell oblong, compressed, slightly gaping at both ends; hinge- teeth +; ligament external, prominent; siphonal inflection deep, in contact with the pallial line; epidermis often dark. Fig. 263. Psammobia pallida, Desh. Red Sea. Left valve, part of the mantle, and retractor of the siphons removed. Siphons much contracted; a, a, adductors, DP; Pp, pedal muscles. Animal, mantle open, fringed; siphons yerylong, slender, nearly equal, longitudinally ciliated, orifices with 6—8 cirri; foot large, tongue-shaped; palpi long, tapering; gills unequal, recumbent, few plaited. ‘ Distribution, 50 species. Norway, Britain, India, New Zea- — land, Pacific. Littoral — coralline zone, 100 fathoms. P. gari is eaten in India. | Fossil, 55 species. Oolite? Eocene—. United States, Europe. SANGUINOLARIA, Lamarck. ‘ Name, from the type, Solen sanguinolentus, Chemn. Synonyms, Soletellina (diphos), Bl. Lobaria, Schumacher. Aulus, Oken. CONCHIFERA. 423 Example, 8. livida, Pl. XXII., Fig. 1. §. diphos, Fig. 2. 8. orbiculata, Fig. 3. Shell oval, compressed, rounded in front, attenuated and slightly gaping behind; hinge-teeth %, small; siphonal inflec- tion very deep, connected with the pallial line; ligament ex- ternal, on very prominent fulcra. Animal, mantle open, fringed; siphons very long, branchial largest orifices fringed; foot large, broadly tongue-shaped, compressed ; palpilong pointed; gills recumbent, inner lamin free, dorsal border wide. Distribution, 20 species. West Indies, Red Sea, India, Mada- gascar, Japan; Australia, Tasmania, Peru. Fossil, 30 species. Eocene—. United States, Europe. SEMELE, Schumacher, 1817. Etymology, Semele, in Greek myth. the mother of Bacchus. Synonym, Amphidesma, Lamarck, 1818.* Type, 8. reticulata, Pl. XXI., Fig. 11. Shell rounded, sub-equilateral, beaks turned forwards; pos- terior side slightly folded; hinge-teeth 2.2, laterals elongated, distinct in the right valve; external ligament short, cartilage internal, long, oblique; pallial sinus deep, rounded. Distribution, 60 species. West Indies, Brazil, India, China, Australia, Peru. Fossil, 30 species. ocene—. United States, Europe. Sub-genera. Cumingia, G. Sowerby. C. lamellosa, Pl. XXL, Fig. 12. Shell slightly attenuated and gaping behind, lamel- lated concentrically ; cartilage-process prominent; pallial sinus very wide. Distribution, 10 species. In sponges, sand, and the fissures of rocks, — 7 fathoms. West Indies, India, Aus- tralia, West America. Fossil, Miocene—. Wilmington, North Carolina. , Syndosmya, Recluz. Synonyms, Abra, Leach MS. Erycina (part), Lamarck, 1805.¢ JTZ'ype, S. Alba, Pl. XXI., Fig. 13. Shell small, oval, white and shining; posterior side shortest; umbones directed backwards ; cartilage-process oblique; hinge- teeth minute or obsolete, laterals distinct; pallial sinus wide and shallow. Animal with the mantle open, fringed; siphons * The name Amphi-desma, as employed by Lamarck, included species of Semele, Loripes, Syndosmya, Mesodesmu, Thracia, Lyonsia, and Kellia ; in addition to which it has since been applied to some Oolitic Myacites. 7 The name Frycina was originally applied by Lamarck to a number of minute fossil shells, including sp. of Syndosmya, Venus, Lucina, Tellina, Astarte, and Kellia. In 1808 Fabricius employed it for a well-known group of insects. Y 2 — 484 MANUAL OF THE MOLLUSCA. long, slender, diverging, anal shortest, orifices plain; foot = large, tongue-shaped, pointed; palpi triangular, nearly as large — as the gills; branchiz unequal, triangular. Distribution, Norway, Britain, Mediterranean, Black Sea, India. The species are few, and mostly boreal, ranging from the laminarian zone to 180 fathoms. (Forbes.) They live buried in sand and mud, but when confined are able to creep up the sides of the vessel with their foot. (Bouchard.) Jossil, 6 species. Hocene—. Britain, France. Scrobicularia, Schumacher. Synonyms, Trigonella (part), Costa (not L.), Ligula (part), Mont. ‘‘Le Lavignon” (Reaumur), Cuy. Listera, Turt. (not R. Brown). Lutricola, Bl. Mac- tromya, D’Orbigny (not Ag.) Type, S. piperata (Belon), Gmelin, ' Pl. XXI., Fig. 14. (See p. 60.) Shell oval, compressed, thin ; sub-equilateral ; ligament external, slight; cartilage-pit shallow, triangular; hinge-teeth small, 1 or 2 in each valve, laterals obsolete ; pallial sinus wide and deep. Animal with the mantle open, margins denticulated ; siphons very long, slender, separate, orifices plain; foot large, tongue- shaped, compressed ; palpi very large, triangular, gills minutely striated, the outer pair directed dorsally. Lives buried, verti- cally, in the mud of tidal estuaries, five or six inches deep. (Montagu.) The siphons can be extended to five or six times the length of the shell. (Deshayes.) The animal has a peppery taste, but is sometimes eaten on the coasts of the Mediterranean. Distribution, 20 species. Norway, Britain, Mediterranean, Senegal. Fossil, 4 species. Tertiary. Europe. MesopxEsMA, Deshayes. Etymology, meso, nriddle, desma, ligament. Synonyms, Eryx, Sw. (not Daud.). Paphia (part), Lamarck, 1799 (see p. 464, note). Erycina (part), Lamarck, 1818 (not Lamarck, 1805, nor Fabr., 1808). ‘‘ Donacille,’’ Lamarck, 1812 (not characterised) Examples, M. glabratum, Pl. XXI., Fig. 15. M. donacium, ' Fig. 16. Shell trigonal, thick, compressed, closed; ligament internal, in a deep central pit; a minute anterior hinge-tooth, and 1—1 lateral teeth in each valve ; muscular scars deep; pallial sinus small. Animal with mantle- margins plain ; siphons short, thick, and | CONCHIFERA. 485 separate, orifices cirrated, branchial cirri dendritic; foot com- pressed, broadly lanceolate ; gills large, unequal; palpi small. Sub-genus. Anapa, Gray. A. Smithu, Pl. XXI., Fig. 17. Umbones anterior, siphonal inflection obsolete. Ceronia, Gray. Lateral teeth marked with coarse oblique strice. ? Davila, Gray. Laterals unequal; anterior teeth small and erect. Distribution, 31 species. West Indies, Mediterranean, Crimea, India, New Zealand, Chili; sands at low water. Fossil, 7 species. Neocomian—. United States, Europe. (Donacilla, D’ Orbigny.) ErviiiA, Turton. Lentil-shell. Etymology, ervilia, diminutive of ervwm, the bitter-vetch. Type, K. nitens, Pl. XXI., Fig. 18. Shell minute, oval, close ; cartilage in a central pit; right valve with a single prominent tooth in front and an obscure tooth behind ; left valve with 2 obscure teeth ; no lateral teeth; pallial sinus deep. _ Distribution, 2 species. West Indies, Britain, Canaries, Mediterranean, Red Sea. —50 fathoms. Donax, L. Wedge-shell. Example, D. denticulatus, Pl. XXJ., Fig. 19. Etymology, donax, a sea-fish. (Pliny.) Synonyms, Chione, Scop. Cuneus, Da Costa. Capisterium, Meuschen.* lLatona and Hecuba, Schum. LEgeria, Lea (not Roissy). Sheli trigonal, wedge-like, closed ; front produced, rounded ; posterior side short, straight; margins usually crenulated ; hinge-teeth 2.2; laterals 1—1 in each valve ; ligament external, prominent; pallial sinus deep, horizontal. Animal with the mantle fringed; siphons short and thick, diverging, anal orifice denticulated, branchial -with pinnate cirri; foot very large, pointed, sharp-edged, projected quite in front; gills ample, recumbent, outer shortest; palpi small, pointed. Distribution, 68 species. Norway, Baltic, — Black Sea, all tropical seas. In sands near low-water mark (—S8 fathoms) buried an inch or two beneath the surface. Fossil, 45 species. Carb.—. United States, Europe. * Meuschen was a Dutch auctioneer; the names occur in his “sale catalogues.” didiote imposuere nomina absurda. Linneus. 486 MANUAL OF THE MOLLUSCA. Sub-genera. ? Amphichena, Phil. A. Kindermanni, California. — Shell oblong, nearly equilateral, gaping at each end; teeth 3; ligament external, pallial line sinuated. Iphigenia, Schum. (Capsa, Lam., 1818, not 1891. Donacina, Fér.) I. Brasiliensis, Pl. XXI., Fig. 20. Shell nearly equi- lateral, smooth ; hinge-teeth 2.2, one bifid, the other minute ; laterals remote, obsolete in the left valve; margins smooth. Distribution, 5 species. West Indies, Brazil, West Africa, Pacific, Central America. Inhabits estuaries. J. ventricosa, Deshayes, is rayed like Galatea, and has its beaks eroded. ? Isodonta (Deshayesii). Buy. Bull. Soc. Geol. Oolite. France, England. GALATEA, Bruguiére. Synonyms, Egeria, Roissy. Potamophila, Sowerby. Mega- desma, Bowdich. Type, G. reclusa, Pl. XXT., Fig. 21. Shell very thick, trigonal, wedge-shaped ; epidermis smooth, olive ; umbones eroded ; hinge thick, teeth 1.2, laterals indis- tinct; hgament external, prominent; pallial sinus distinct. Animal with the mantle open in front; siphons moderate, with 6—8 lines of cilia, orifices fringed ; foot large, compressed ; palpi long, triangular; gills unequal, united to the base of the siphons, the external pair divided into two nearly equal areas by a longitudinal furrow, indicating their line of attach- ment. Distribution, 6 or 7 species? Nile, and rivers of West Africa. FAMILY XVII.—SoLENIDA. Shell elongated, gaping at the ends; ligament external; hinge-teeth usually 2.3, compressed, the posterior bifid. External shell layer with definite cell-structure, consisting of long prisms, very oblique to the surface, and exhibiting nuclei; inner layer nearly homogeneous. Animal with a very large and powerful foot, more or less cylindrical ; siphons short and united (in the typical Solens, with long shells) or longer and partly separate (in the shorter and more compressed genera); gills narrow, prolonged into the branchial siphon. SoueEn (Aristotle), L. Razor-fish. Type, 8. siliqua, Pl. XXII., Fig. 4. CONCHIFERA: 487 Synonyms, Hypogzea, Poli. Vagina, Megerle. Ensis, Schum. Ensatella, Sw. Shell very long, sub-cylindrical, straight, or slightly recurved, margins parallel, ends gaping; beaks terminal, or sub-central ; Fig. 264. Solen siliqua, L. +; the valves forcibly opened, and mantle divided as far as the ventral foramen, to show the foot. hinge-teeth 2; ligament long, external; anterior muscular impression elongated; posterior oblong; pallial line extending beyond the adductors; sinus short and square. Animal with the mantle closed except at the front end, and a minute ventral opening; siphons short, united, fringed; palpi broadly triangular ; foot cylindrical, obtuse. Distribution, 23 species. World-wide except Arctic seas ;— 100 fathoms. Fossil, 40 species. Carb.—. United States, Europe. The Razor-fishes live buried vertically in the sand, at extreme low water, their position being only indicated by an orifice like a key-hole; when the tide goes out they sink deeper, often penetrating to a depth of one or two feet. They never volun- tarily leave their burrows, but if taken out soon bury themselves again. They may be caught with a bent wire, and are excellent articles of food when cooked. (Forbes.) CULTELLUS, Schumacher. Type, C. lacteus, Pl. XXII., Fig. 5. Etymology, cultellus, a knife. Shell elongated, compressed, rounded and gaping at the ends ; hinge-teeth 2.3 ; beaks in front of the centre, supported inter- nally by an oblique rib; pedal impression behind the umbonal rib; posterior adductor trigonal; pallial line not prolonged behind the posterior adductor; sinus short and square. Animal (of C. Javanicus) with short, fringed siphons; gills narrow, half as long as the shell, transversely plaited; palpi large, angular, broadly attached; foot large, abruptly trun- cated. Distribution, 5 species. Africa, India, Nicobar. : Sub-genera. Ceratisolen, Forbes. (Polia, D’Orbigny. Pharus, 488 MANUAL OF THE MOLLUSCA. Leach, MS. Solecurtoides, Desm.) OC. legumen, PI. XXII, Fig. 6. Shell narrow, sub-equilateral, anterior adductor i impres- sions elongated, a second pedal scar near the pallial sinus. Animal with a long, truncated foot; siphons separate, diverg- ing, fringed. Distribution, 1 species. Britain, Mediterranean, Senegal, Red Sea. Fossil, 3 species. Pliocene—. Italy. Machera, Gould. (Siliqua, Megerle. Leguminaria, Schum.) M. polita, Pl. XXII., Fig. 7. Shell smooth, oblong; epidermis polished; umbonal rib extending across the interior of the valve ; pallial sinus short. The animal, figured by Middendorff, is similar to Solecurtus. Distribution, India, China, Ochotsk, Oregon, Sitka, Behring’s Sea, Newfoundland. MM. costata, Say, 1s often obtained from the maw of the cod-fish. fossil, 4 species. Upper Greensand—. Britain, France. Pharella, Gray. Shell nearly cylindrical; anterior muscular impression elongated. SoLEcuRTUws, Blainville. Etymology, solen and, curtus, short. Synonyms, Psammosolen, Risso. Macha, Oken. SGiliquaria, Schum. Tagelus, Gray. Examples, 8. strigilatus, Pl. XXII., Fig. 8. §. Caribzeus, PR ROM, Fig. 9. Shell elongated, rather ventricose, with sub-central beaks ; margins sub-paraliel; ends truncated, gaping ; ligament promi- nent ; hinge-teeth 3 ; pallial sinus very deep, rounded ; posterior adductor rounded. Animal very large and thick, not entirely retractile within the shell; mantle closed below; pedal orifice and foot large; palpi triangular, narrow, lamellated inside; gills long and narrow, outer much the shortest; siphons separate at the ends, united and forming a thick mass at their bases; anal orifices plain, branchial fringed. The Solecurti bury deeply in sand or mud, usually beyond low water, and are difficult to obtain alive. P. Caribeus occurs in countless myriads in the bars of American rivers, and on the coast of New Jersey in sand exposed at low water; by removing ‘three or four inches of sand its burrows may be discovered ; they are vertical cylindrical cavities, 13 inches in diameter and 12 or more deep; the animal holds fast by the expanded end of its foot. Distribution, 25 species. United States, Britain, Mediterranean, West Africa, Maddie! Fossil, 30 species. Neocomian—. United States, Europe. | CONCHIFERA. 489 Sub-genus. Novaculina, Benson. N. gangetica, Pl. XXII., Fig. 10. Shell oblong, plain; epidermis thick and dull ; pallial sinus rather small; anterior pedal scar linear. Distribution, India, China. In the mud of river-estuaries. Faminty XVIII.—MyYacipz. Shell thick, strong and opaque; gaping posteriorly ; pallial line sinuated; epidermis wrinkled. Structure more or less distinctly cellular, with dark nuclei near the outer surface; cartilage process composed of radiated cells. Animal with the mantle almost entirely closed; pedal aper- ture and foot small; siphons united, partly or wholly retractile ; branchiz two on each side, elongated. y t Ih ~ 4 My} Fig. 265. Mya truncata, L. 4, Brit. (after Forbes.) Mya, L. Gaper. EHiymology, myax (-acis), a mussel, (Pliny.) Synonym, Platyodon, Conrad. Types, M. truncata, Pl. XXIII., Fig. 1. M. Arenaria, Fig. 207, p. 396. Shell oblong, inequivalve, gaping at the ends; left valve smallest, with a large flattened cartilage process; pallial sinus large. Animal with a small straight linguiform foot; siphons com- bined, covered with epidermis, partially retractile; orifices fringed, the branchial opening with an inner series of large tentacular filaments; gills not. prolonged into the siphon; palpi _ elongated, free. M. anatina, Chemn. (Tugonia, Gray), West coast of Africa; posterior side extremely truncated ; similar cartilage-processes in each valve. Jessil, Miocene; Dax, and the Morea Distribution, 10 species. Northern Seas, West Africa, Philip~ pines, Australia, California. The Myas frequent soft bottoms, especially the sandy and gravelly mud of river-mouths; they range from low water to 25 fathoms, rarely to 100 or 146 y3 490 MANUAL OF THE MOLLUSCA. fathoms. J. arenaria burrows a foot deep; this speciesand M, truncata are found throughout the northern and Arctic seas, from Ochotsk and Sitka to the Russian Ice-meer, the Baltic, and British coast; in the Mediterranean they are only found fossil. They are eaten in Zetland and North America, and are excellent articles of food. In Greenland they are sought after by the walrus, the Arctic fox, and birds. (0. Fabricius.) Fossil, 17 species. Pliocene—. United States, Britain, Sicily. Most of the fossil ‘‘Myas” have an external ligament, and are related either to Panopea or Pholadomya. CorLuLA, Bruguiére. Hiymology, corbula, a little basket. Type, C. sulcata, Pl. X XITI., Fig. 2. Synonyms, Erodona, Daud. (=Pacyodon, Beck.) Agina, Turt. Shell thick, inequivalve, gibbose, closed, produced posteriorly ; right valve with a prominent tooth in front of the cartilage pit ; left valve smaller, with a projecting cartilage process; pallial sinus slight; pedal scars distinct from the adductor impressions. Animal with very short, united siphons; orifices friiged ; anal yalve tubular; foot thick and pointed ; palpi moderate ; gills 2 on each side, obscurely striated. Distribution, 66 species. United States, Norway, Britain, Mieiiienrdinonmn' West Africa, China. Inhabits sandy bottoms; lower laminarian zone—80 fathoms. Fossil, 120 species. Inferior Oolite—. United States, Europe, India. The external shell-layer consists of fusiform cells; the inner is homogeneous and adheres so slightly to the outer layer, that it is very frequently detached in fossil specimens. Corbulomya, Nyst (C. complanata, Sby.), Crag., Britain, Sub-genera, Potamomya, J. Sowerby. P. gregaria, Eocene, Isle of Wight. Cartilage process broad and spatulate, received between two obscure teeth in the right valve. The estuary Oorbule differ very little from the marine species. /P. labiata (Azara, D’Orbigny), Pl. XXIII., Fig. 3, lives buried in the mud of the River Plata, but not above Buenos Ayres, and con- sequently in water which is very little influenced by the superficial ebb of the river. The same species is found in banks widely dispersed over the Pampas near San Pedro, and many places in the Argentine Republic, five yards above the river Parana. (Darwin.) Sphenia, Turt. §. Binghami, Pl. XXIII., Fig. 4. Shell CONCHIFERA. 491 oblong; right valve with a curved, conic tooth in front of tho oblique, sub-trigonal cartilage-pit. Animal with thick united siphons, fringed at the end, anal valve conspicuous ; foot finger- like, with a byssal groove. Distribution, 2 species. Britain, France. Burrowing in oyster-shells and limestone, in t0—25 fathoms. ossil, 20 species. Tertiary. Europe. NERA, Gray. . Etymology, Neera, a Roman lady’s name. Type, N. cuspidata, Pl. XXIII., Fig. 5. Synonym, Cuspidaria, Nardo. | Shell globular, attenuated, and gaping behind ; right valve a little the smallest; umbones strengthened internally by a rib - on the posterior side ; cartilage process spatulate, in each valve (furnished with a movable ossicle,—Deshayes), with an obsolete tooth in front, and a posterior lateral tooth; pallial sinus very shallow. Animal with the mantle closed ; foot lanceolate ; siphons short, united, branchial largest, anal with a membranous valve, both with a few long, lateral cirri. _ Distribution, 22 species. Norway, Britain, Mediterrarean, Canaries, Madeira, China, Moluccas, New Guinea, Chili. From 12—200 fathoms. Fossil, 14 species. Oolite—. Britain, Belgium, Italy. Fig. 266. Thetis, minor, Sby. Neocomian, I. Wight. THETIS,. Sowerby. Etymology, Thetis, in Greek mythology, a sea-nymph. Synonyms, Poromya (anatinoides), Forbes. Embla (Korenii), Lovén? Inoceramus (impressus), D’Orb? Corbula (gigantea), Sby. Type, T. minor, Fig. 266. T. hyalina, Pl. XXII., Fig. 11. Shell sub-orbicular, ventricose, thin, trauslucent, surface regularly granulated, interior slightly nacreous; ligament (/) 492 MANUAL OF THE MOLLUSCA. external; hinge-teeth 1 or 2; umbones strengthened inside by a posterior lamina; adductor (a, a’) and pedal impressions (p) separate, slightly impressed, posterior adductor bordered by a ridge ; pallial line nearly simple, sub-marginal. Animal with short siphons, the branchial largest, surrounded at their base by 18-20 tentacles, generally reflected on the _ shell; mantle open in front; foot long, narrow, and slender. (M‘Andrew.) Distribution, 5 species. Norway, Britain, Mediterranean, Madeira, Borneo, China. 40—150 fathoms. _ Fossil, 17 species. Neocomian—. Britain, Belgium, France, South India. | Sub-genus? Hucharis, Recluz; Corbula quadrata, Hinds, Guadaloupe. Shell equivalve, obliquely keeled, gaping; beaks anterior ; hinge-teeth 1—1; ligament external; pallial line © simple; surface granulated. PanopHA, Menard de la Groye. Etymology, Panopée, a Nereid. Example, P. Americana, Pl. XXTI., Fig. 12. Synonym ? Pachymya (gigas), Sby. Upper Greensand. Britain, France. Type, P. glycimeris. Fig. 267. Shell equivalve, thick, oblong, gaping at each end; ligament external, on prominent ridges; 1 prominent tooth in each valve; pallial sinus deep. Animal with very long, united siphons, invested with thick, wrinkled epidermis ; pedal orifice small, foot short, thick, and grooved below; gills long and narrow, extending far into the branchial siphon, the outer pair much narrower than the inner, faintly pectinated ; palpi long, pointed, and striated. In P. Norvegica the pallial line is broken up into a few scattered spots, as m Saaicava; the animal itself is like a gigantic Saxicava. (Hancock.) This species ranges from Ochotsk to the White Sea, Norway, and North Britain; it was formerly an inhabitant of the Mediterranean, where it now occurs fossil. (= P. Bivone, Philippi.) The British speci- — mens have been caught, accidentally, by the deep-water — fishing-hooks. P. Natalensis is found at Port Natal, buried in the sand at low water; the projecting siphons first attracted attention (doubtless by the strong jets of water they sent up when molested), but the shells were only obtained by digging to the depth of several feet. The Mediterranean species P. g'ycimeris attains a length of 6 or 8 inches. CONCHIFERA. 493 Fig. 267 represents the animal of Panopea glycimeris, as seen on the remoyal of the left valye and thin part of the mantle. It was obtained on the coast of Sicily, and presented to the Gloucester Museum by Cap- tain Guise. Mantle and siphons covered with thick, dark, wrinkled epi- dermis; siphons united, thick, contractile ; pedal orifice small, in the middle of the anterior gape; foot small (/), body oval (5), with a prominent heel ; pallial muscle (m) continuous; with a deep siphonal inflection (s); lips broad and plain, palpi triangular, deeply plaited (t) ; gills unequal (much contracted in spirit), reaching the com- mencement of the siphons; inner gills prolonged between the palpi, plaits in pairs, each lamina being composed of vas- cular loops arranged side by side; margin grooved, dorsal border of inner lamina unat- tached ; outer gills shorter and narrower, formed of a single series of branchial loops placed one behind the other, dorsal border wide and fixed. Distribution, 11 _ species. Northern Seas, Mediterranean, Cape, Australia, New Zealand, Patagonia. Low water — 90 fathoms. — : Fossil, 140 species. Inferior Oolite—. United States, Europe, India. Fig. 267. Puivpea Glycuneres 2. The size of the original. a, a', adductor muscles; p, posterior pedal muscle; 7, renal organ. GLYCIMERIS, Lamarck. Etymology, glukus, sweet, meris, bitter. Type, G. siliqua, Pl. XXII., Fig. 14 and Fig. 268. Synonym, Cyrtodaria, Daud. 494 MANUAL OF THE MOLLUSGA. Shell oblong, gaping at each end; posterior side shortest ; ligament large and prominent; epidermis black, extending beyond the margins; anterior muscular scar long, pallial im- pression irregular, slightly sinuated. Animal larger than its shell, sub-cylindrical ; mantle closed, siphons united, protected by a thick envelope; orifices small ; aS — LL KN Fig. 268, ha siligua, Chemn. Newfoundland. @, a, adductor muscle; p, pedal muscle; s, siphonal muscle; f, foot; t, labial tentacles ; g, gills, much contracted and crumpled. pedal opening small anterior ; foot conical; palpi large, striated inside, the posterior border plain; gills large, extending into the branchial siphon. Distribution, 2 species. Arctic Seas, Cape Parry, North Western America, Newfoundland. Fossil, Pliocene—. Britain, Belgium. s FAMILY XITX.—ANATINIDA. Sheil often inequivalve, thin; interior nacreous; surface granular; ligament external, thin; cartilage internal, placed in corresponding pits and furnished with a free ossicle; muscular impressions faint, the anterior elongated ; pallial line usually sinuated. Animal with mantle-margins united; siphons long, more or less united, fringed; gills single on each side, the outer lamina prolonged dorsally beyond the line of attachment. Pholadomya and its fossil allies have an external ligament only; has no ossicle, The external surface of these shells is often rough with large calcareous cells, sometimes ranged in lines, and covered by the epidermis; the outer layer consists of polygonal cells, more or less sharply defined; the inner layer is nacreous. a UVONCHIFERA. 495 ANATINA, Lamarck. Lantern-shell. Type, A. rostrata, Pl. XXIII, Fig. 7. (Anatinus, pertain- ing to a duck.) Synonyms, Laternula, Bolten MS. Auriscalpium, Muhlf. Osteodesma, Blainyille. Cyathodonta (undulata), Conrad ? West America, Shell oblong, ventricose, sub-equiyalve, thin and translucent, posterior side attenuated and gaping ; umbones fissured, directed backwards, supported internally by an oblique plate; hinge with a spoon-shaped cartilage process in each vyalye, furnished in front with a transverse ossicle; pallial sinus wide and shallow. Animal with a closed mantle and long united siphons, clothed with wrinkled epidermis; gills one on each side, thick, deeply plaited ; palpi very long and narrow; pedal opening minute, foot very small, compressed. Distribution, 20 species. India, Philippines, New Zealand, West America. Fossil, 50 species. Deyonian ?—Oolite—. United States, Europe. Sub-genera. Periploma (inequivalvis), Schum. ‘‘ Spoon- hinge” of Petiver ; oval, inequivalve, left valve deepest; pos- terior side very short and contracted. Distribution, West Indies, South America. Cochlodesma, Couthouy. C. preetenue, Pl. XXTII., Fig. 8. (Bontia, Leach MS. Ligula, Mont., part,) Oblong, compressed, thin, slightly inequivalye ; umbones fissured ; cartilage processes prominent, ossicle minute; pallial sinus deep. Animal witha broad, compressed foot; siphons long, slender, divided through- out; gills one on each side, deeply plaited, divided by an oblique furréw into two parts, the dorsal portion being narrower, com- posed of a single lamina only, and attached by its whole inner aa (Hancock. ) ‘Distribution, 2 species. United States, ; , Mediterranean. Jossil, Pliocene, Sicily. Corcomyc, Agassiz. C. undulata, Sowerby. (—Rhynchomya, Agassiz.) Shell very thin, elongated, compressed, attenuated posteriorly ; sides concentrically furrowed, umbones fissured, posterior (cardinal). < more or less defined. fossil, 12 species. Oolite—Neocomian. Hurope. THRACIA (Leach), Blainville. Synonyms, Odoncinetus, Costa. Corimya, Agassiz. Rupiccla (concentrica), Bellevue. 496 MANUAL OF THE MOLLUSCA. Type, T. pubescens, Pl. XXIII., Fig. 9 Shell oblong, nearly equivalve, he phtly obtain essed, attenuated and gaping posteriorly, smooth, or minutely scabrous; ; cartilage processes thick, not prominent, with a crescentic ossicle ; pallial sinus shallow. Outer shell layer composed of distinct, nucleated — cells. Animal with the mantle closed; foot linguiform; siphons rather long, separate, with fringed orifices; gills single, thick, plaited; palpi narrow, pointed. _T. concentrica and 7’. distortu, Mont., are found in the crevices of rocks, and burrows of Sawxicuva ; they have been mistaken for boring-shells. Distribution, 17 species. Greenland, United States, Norway, Britain, Mediterranean, Canaries, China, Sooloo; 4—110 fathoms. Fossil, 86 species. (Trias?) Lower Oolite—. United States, Europe. PuHotapomya, G. Sowerby. Recent Type, P. candida. Pl. XXII, Fig. 15. I. Tortola. Shell oblong, equivalve, veutricose, gaping behind; thin and translucent, ornamented with radiating ribs on the sides’ liga- ment external; hinge with one obscure tooth in each valve; pallial sinus large. Animal with a single gill on each side, thick, finery plaited, grooved along its free border, the outer lamina prolonged dorsally ; mantle with a fourth (ventral) orifice. (Owen.) Distribution, 1 species. Tropical Africa. Fossil, 160 species. Lias—. United States, Europe, Algeria, Thibet. Homomya (hortulana), Agassiz. Shell thick, concentrically furrowed, without radiating ribs; 12 species. Oolites, E ope. | Tyleria, Adams. Oar bilaed 3 inserted in a spoon- -shaped Ene. ; interior of shell with a layer of carbonate of lime Fhe spoon-shaped hollow and the anterior edge. Myactrxs (Schlotheim), Bronn. Synonyms, Myopsis (Jurassi), Agassiz, — ie iGuetin ya, Agassiz, — Arcomya (Helvetica), Agassiz. Mactromya (mactroides), Ag. Anoplomya (lutraria), Krauss. Example, M. sulcatus, Fleming. (Allorisma, King, Pal. Tr., 1950, Pl. XX., Fig. 5.) A Shell oblong, ventricose, gaping, thin, often concentrically — CONCHIFERA. 497 furrowed; umbones anterior; surface granulated; ligament external; hinge with an obscure tooth or edentulous; muscular impressions faint; pallial line deeply sinuated. Fossil, 50 species. Lower Silurian—Lower Chalk. United States, Europe, South Africa. Sub-genera ? Goniomya, Agassiz. Mya literata, Pl. X-XII., Fig. 16. (Lysianassa, Minster, not M. Edwards.) Shell equi- valve, thin, granulated; ligament external, short, prominent. Fossil, 33 species. Upper Lias—Chalk. Europe. Tellinomya (nasuta), Hall; Silurian, United States, Europe. Not characterised. ? Grammysia, Verneuil. Nucula cingulata, His. Upper Silurian, Europe. Valves with a strong transverse fold extend- ing from the umbones to the middle of the ventral margin. ? Sedgwickia (corrugata), M‘Coy. =? Leptodonus (senilis), M‘Coy. Shell thin, ventricose, concentrically furrowed in front ; escutcheon long and flat. Silurian—Carb. urope. RIBEIRIA, Sharpe, 1853. Sheli gaping at both ends; sub-ovate, rounded in front, elon- gated and rather attenuated behind; punctate-striate ; casts of interior with a large umbonal impression (caused by a cartilage- plate, as in Lyonsia ?) and a notch in front of it. Fossil. Lower Silurian. Portugal. CEROMYA, Agassiz. Etymology, keraos, horned, mya, mussel. Type, C. concentrica (Isocardia) Sowerby, Min. Con. 491, Fig. 1. Shell Isocardia-shaped, slightly inequivalve? very thin, granulated, often eccentrically furrowed; ligament external; hinge edentulous; right valve with an internal lamina behind the umbo ; pallial line scarcely sinuated ? Fossil, 14 species. Inferior Oolite—. Greensand? Europe. Sub-genus ? Gresslya(sulcosa) Ag. (Amphidesma and Unio, species, Philippi). Shell oval, rather compressed; umbones anterior, incurved, not prominent; valves thin, close, smooth or concentrically furrowed; pallial sinus deep. Fossil, 50 species. Lias—Portlandian. Europe. The lamina within the posterior hinge-margin of the right valve produces a furrow in the casts, which are more common than specimens retaining the © shell, 498 MANUAL OF THE MOLLUSCA. ? CARDIOMORPHA, Koninck. Type, C. oblonga (Isocardia), Sowerby (not Koninck). Car- bonate of lime. Shell Isocardia-shaped, smooth or concentrically furrowed, umbones prominent, hinge edentulous; hinge-margin with a narrow ligamental furrow, and an obscure internal cartilage groove. Fossil, 38 species. Lower Silurian—Carb. North America, Europe. EDMONDIA, KONINCK. Example, E. sulcata, Ph. (T. Pal. Soc. 1850, Pl. XX., Fig. 5.) Carb. Britain. Synonyms, Allorisma, King (part). Sanguinolites, M‘Coy (part). Shell oblong, equiys!ve, thin, concentrically striated, close ; umbones anterior; ligamental grooves narrow, external ; hinge-line thin, edentulous, furnished with large oblique cartilage plates, placed beneath the umbones, and leaving space for an ossicle? or the plate may be equivalent to the sub-um- bonal blade in Pholas ; pallial line simple ? Fossil, 4 species. Carb.—Permian. Europe. Sub-genus. Scaldia, Ryckholt, 1856. Carb. Tournay. Shell like Edmondia, with a single cardinal tooth in each valve. LyonstA, Turton, 1822 (not R. Brown). Synonyms, Magdala, Leach, 1827. Myatella, Brown. Pan- dorina, Scacchi. Type, L. Norvegica, Pl. XXIII., Fig. 10. Shell nearly equivalve, left valve largest, thin, sub-nacreous, close, truncated posteriorly; cartilage plates oblique, covered by an oblong ossicle; pallial sinus obscure, angular. Struc-_ ture intermediate between Pandora and Anatina ; outer layer composed of definite polygonal cells. Animal with the mantle closed ; foot tongue-shaped, grooved, © byssiferous; siphons very short, united nearly throughout, fringed; lips large, palpi narrow, triangular. Distribution, 12 species. Greenland, North Sea, Norway, West Indies, Madeira, India, Borneo, Philippines, Peru. L. Norvegica ranges from Norway to the sea of Ochotsk; in | 15—80 fathoms. ee -— CONCHIFERA. 499 Fossil ? Miocene—. Europe. (100 species. Lower Silurian—. D’Orbigny. ) ? Hntodesma (Chilensis), Phil. Shel? thin, saxicava-shaped, slightly inequivalve and gaping, covered with thick epidermis ; hinge edentulous; each valve with a semicircular process con- taining the cartilage. PanDoRA (Solander), Bruguiére. Type, P. rostrata, Pl, XXII., Fig. 11. (Pandora, the Grecian Eve.) Shell inequivalve, thin, pearly inside ; valves close, attenuated behind; right valve flat, with a diverging ridge and cartilage furrows; left valve convex, with two diverging grooves at the hinge; pallial line slightly sinuated. Outer layer of regular, vertical, prismatic cells, 250 times smaller than those of Pinna (Fig. 217). (Carpenter.) Animal with mantle closed, except a small opening for the narrow, tongue-shaped foot; siphons very short, united nearly throughout, ends diverging, fringed ; palpi triangular, narrow ; gills plaited, one on each side, with a narrow dorsal border. Distribution, 18 species. United States, Spitzbergen, Jersey, Canaries, India, New Zealand, Panama; 4—110 fathoms, bur- rowing in sand and mud. Fossil, 14 species. Carb.—. United States, Britain. Myapora, Gray. Type, M. brevis, Pl. XXIII., Fig. 12. Shell trigonal, rounded in front, attenuated and truncated behind ; right valve convex, left flat; interior pearly ; cartilage narrow, triangular, between two tooth-like ridges in the left valve, with a free sickle-shaped ossicle; pallial line sinuated ; structure ike Anatina ; outer cells large, rather prismatic. Distribution, 10 species. New Zealand, New South Wales, Philippines. MyocHama, Stutchbury. Type, M. anomioides, Pl. X:XTIT., Fig. 13. Shell inequivalve, attached by the dextral va.ve and modified by form of surface of attachment; posterior side attenuated ; left valve gibbose; cartilage internal, between two tooth-like projections in each valve, and furnished with a movable ossicle; anterior muscular impression curved, posterior rounded, pallial sinus small. Animal with mantle-lobes united ; pedal opening and siphons 500 MANUAL OF THE MOLLUSCA. surrounded by separate areas ; siphons distinct, unequal, small, slightly fringed ; a minute fourth orifice close to the base of the branchial siphon ; visceral mass large, foot small and conical ; mouth rather large, upper lip hood-like; palpi tapering, few- plaited ; gills one on each side, triangular, plaited, divided by an oblique line into two portions; excurrent channe’s four, two at the base of the gills and two below the dorsal lamine. (Hancock, An. Nat. Hist., 1853.) Distribution, 5 species. New South Wales; attached to Crass- atella and Trigonia, in 8 fathoms water; the fry (as indicated by the umbones) is free, regular, and Myadora-shaped. CHAMOSTREA, Roissy. Type, C. albida, Pl. XXIII., Fig. 14. Synonym, Cleidotheerus, Stutch. Shell mnequivalve, chama-shaped, solid, attached by the anterior side of the deep and strongly-keeled dextral valve ; umbones anterior, sub-spiral; left valve flat, with a conical tooth in front of the cartilage; cartilage internal, with an oblong, curved ossicle; muscular impressions large and rugose, the anterior very long and narrow ; pallial line simple. . Animal with mantle-lobes united by their extreme edge between the pedal orifice and siphons; pedal opening small, with a minute ventral orifice behind it; siphons a little apart, very short, denticulated; body oval, terminating in a small, compressed foot; lips bilobed, palpi disunited, rather long and obtusely pointed; gills one on each side, large, oval, deeply plaited, prolonged in front between the palpi, united posteriorly; each gill traversed by an oblique furrow, the dorsal portion con- sisting of a single lamina with a free margin. (Hancock, An. Nat. Hist., Feb., 1853.) Distribution, 1 species. New South Wales. FAMILY X_X.—GASTROCHENIDA, Shell equivalve, gaping; valves thin, edentulous, united by a ligament, sometimes cemented to a shelly tube when adult; adductor impressions 2, pallial line sinuated. Animal elongated, truncated in front, produced behind into two very long, united, contractile siphons, with cirrated orifices; mantle-margins very thick in front, united, leaving a small opening for the finger-like root; gills narrow, prolonged into the branchial siphon. The shell-fish of this family, the twhicolide of Lamarck, are CONCHIFERA. 501 burrowet's in mud or stone. They are often gregarious, living in myriads near low-water line, but are extracted from their abodes with difficulty. GASTROCHENA, Spengler, 1783. Type, G. modiolina, Pl. XXIII., Fig. 15. (aster, ventra’, chena, gape.) Shell regular, wedge-shaped, umbones anterior; gaping widely in front, close behind; ligament narrow, external; pallial sinus deep. Animal with mantle closed, and thickened in front; foot finger-like, grooved, sometimes byssiferous ; siphons long, sepa- rate only at their extremities; lips simple, palpi sickle-shaped, gills unequal, prolonged freely into the branchial siphon. G. modiolina perforates shells and limestone; its holes are regular, about 2 inches deep and 3 inch diameter; the external orifice is hour-glass shaped, and lined with a shelly layer which projects slightly. When burrowing in oyster-shells it often passes quite through into the ground below, and then completes its abode by cementing such loose material as it finds into a flask-shaped case, having its neck fixed in the oyster-shell ; in some fossil species the siphons were more separated, and the flasks have two diverging necks. The siphonal orifices are rarely 4-lobed; Pl. XXIII., Fig. 1d a. Distribution, 10 species. West Indies, Britain, Canaries, Mediterranean, Red Sea, India, Mauritius, Pacific Islands, Gallapagos, Panama ;—30 fathoms. Fossil, 20 species. Inf. Oolite—. United States, Europe. Sub-genus. Cheena, Retz., 1788. C. mumia. Pl. XXTIII., Fig. 16. (= Fistulana claya, Lam.) Shell elongated, con- tained within a shelly tube; posterior adductor nearly central, with a pedal scar in front; siphonal inflection angular, with its apex joining the pallial line. Tube round, straight, taper- ing upwards, transversely striated, closed at the lower end when complete, and furnished with a perforated diaphragny behind the valves. Distribution, 3 species. Madagascar, India, Philippines, Australia; burrowing in sand or muc. Fossil, Inf. Oolite—. United States, Europe, Southein India. SAXICAVA, Bellevue. Etymology, saxwm, stone, cavo, to excayate. SS. rugosa, i 5 a he oa © 502 MANUAL OF THE MOLLUSCA. Synonyms, Byssomya, Cuy. Rhomboides, Bl. Hiatella (minuta), Daud., Biapholius, Leach. Arcinella (carinata), Phil. Shell when young symmetrical, with 2 minute teeth in each valve; adult rugose, toothless; oblong, equivalve, gaping, ligament external ; pallial line sinuated, not continuous. Animal with mantle-lobes united and thickened in front ; siphons large, united nearly to their ends, orifices fringed ; pedal opening small, foot finger-like, with a byssal groove ; palpi small, free; gills narrow, unequal, united behind and prolonged into the branchial siphon. Five genera and 15 species have been manufactured out of varieties and conditions of this Protean shell. It is found in crevices of rocks and corals, and amongst the roots of sea-weed, or burrowing in limestone and shells; at Harwich it bores in the cement stone (clay iron-stone), at Folkestone in the Kentish- rag, and the Portland stone employed in the Plymouth Break- water has been much wasted by it. Its crypts are sometimes _6 inches deep (Couch); they are not quite symmetrical, and like those of the Lithodomus, are inclined at various angles, so as to invade one another, the last comers cutting quite through their neighbours; they are usually fixed by the byssus to a small projection from the side of the cell. The Saxicava ranges from low water to 140 fathoms; it is found in the Arctic Seas, where it attains its largest size; in the Mediterranean, at the Canaries, and the Cape. It occurs fossil in the Miocene tertiary of Europe and in the United States, and in all the glacial deposits. CLAVAGELLA, Lamarck. Example, C. bacillaris, Pl. XXIIT., Fig. 17. Shell oblong, valves flat, often irregular or rudimentary, the left cemented to the side of the burrow, when adult, the right always free; anterior muscular impression small, posterior large, pallial line deeply sinuated. Tube cylindrical, more or less elongated, sometimes divided by a longitudinal partition ; often furnished, with a succession of siphonal fringes above, and terminating below in a disk, with a minute central fissure, and bordered with branching tubuli. Animal with the mantle closed in front, except a minute slit for the foot, and furnished with tentacular processes ; palpi long and slender; gills 2 on each side, elongated, narrow (floating freely in the branchial siphon °). Some specimens of the recent C. aperta have 3 frills to their tubes, C. bacillaris has twice that number occasionally. They ( . CONCHIFERA. 503 are formed by the siphonal orifices when the animal continues elongating, after having fixed its valve and ceased to burrow; or perhaps, in some instances, when it is compelled to lengthen its tubes upwards by the accumulation of sediment. Brocchi mentions that on breaking the tube of the fossil C. echinata, he sometimes found the shell of a Suwxicava or Petricola beside the loose valve of the Clavagella, into whose tube they must have entered after its death. CO. elongata is found in coral; C. australis lives at low tide, and spirts out water when alarmed. Distribution, 6 species. Mediterranean, Australia, Pacific :— 11 fathoms. Fossil, 14 species. U. Greensand—. Britain, Sicily, Southern India. ASPERGILLUM, Lam. Watering-pot shell. Type, A. vaginiferum, PI. XXIII., Fig. 18. Synonym, Clepsydra, Schum. Shell small, equilateral, cemented to the lower end of a shelly tube, the umbones alone visible externally; tube elongated, closed below by a perforated disk with a minute central fissure ; siphonal end plain or ornamented with (1—8) ruffles. Animal elongated ; mantle closed, thickened and fringed with filaments in front; foot conical, anterior, opposed to a minute slit in the mantle; palpi lanceolate; gills long, narrow, united posteriorly, continued into and attached to the branchial siphon. Distribution, 21 species. Red Sea, Jaya, Australia, New Zealand ; in sand. Fossil, 1 species. (A? Leognanum, Heening. Miocene, Bor- deaux. ) HUMPHREYIA, Gray. Shell developed in the substance of the siphons, which grow with the ventral side uppermost. Distribution, 1 species. South Sea. Famity X XI.—PHOLADIDA. Shell gaping at both ends ; thin, white, brittle, and exceedingly hard ; armed in front with rasp-like imbrications ; without hinge or ligament, but often strengthened externally by accessory yalyes; hinge-plate reflected over the umbones, and a long curved muscular process beneath each; anterior muscular im- pression on the hinge-plate; pallial sinus very deep. Animal club-shaped, or worm-like; foot short and truncated ; 504 MANUAL OF THE MOLLUSCA. mantle closed in front, except the pedal orifice; siphons large, elongated, united nearly to their ends; orifices fringed; gills narrow, prolonged into the exhalent siphon, attached through- out, closing the branchial chamber; palpi long ; anterior shell- muscle acting as substitute for a ieament The Pholadide perforate all substances that are spttist than their own yalves (p. 394) ;* the burrows of Pholas are vertical, quite symmetrical, and seldom in contact... The ship-worms (Teredines) also make symmetrical perforations, and however tortuous and crowded never invade each other, guided either by the sense of hearing or by the yielding of the wood. The burrow has frequently a calcareous lining, within which the shell remains free; T'eredina cements its valyes to this tube when full-grown. The opening of the burrow, at first very minute, may become enlarged progressively by the friction of the siphons, which are furnished with a rough epithelium; but it usually widens with much more rapidity by the wasting of the surface. As the timber decomposes the shelly tubes of the Teredo project, and as the beach wears away the pholas burrows deeper. PuHouas, L. Piddock. Etymolog 9 y, pholas, a burrowing shell-fish, from Niet to bore. Synonyms, Dactylina, Gray. Barnea, Risso. Type, P. dactylus, Fig. 269. Example, P. Bakeri, Pl. XXITI., Fig. 19. Shell elongated, cylindrical; dorsal margin protected by acces- sory valves; pallial sinus reaching the centre of the shell. Animal with a large truncated foot, filling the pedal opening; body with a fin-like termination ; combined siphons large, cylin- drical, with fringed orifices. * M. Cailliaud has proved that these valves are quite equal to the work of boring in limestone, by imitating the natural conditions as nearly as possible, and making such a hole with them. Mr. Robertson also, has kept the living Pholades in blocks of chalk, by the sea-side at Brighton, and has watched the progress of the work. They turn from side to side, never going more than half round in their burrow, and cease to work ag soon as the hole is deep enough to shelter them; the chalk powder is ejected at inter- vals by spasmodic contractions from the branchial siphon, the space between the shell and burrow being filled with this mud. (Journ. Conch., 1853, p. 811.) It is to be re- marked that the condition of the Pholades is always related to the nature of the material in which they are found burrowing; in soft sea-beds they attain the largest size and greatest perfection; whilst in hard, and especially gritty rock, they are dwarfed in size, and all prominent points and ridges appear worn by friction. No notice has been taken of the hypothesis which ascribes the perforation of rocks, &c., to ciliary action, because, in fact, there is no current between the shell or siphons and the wall of the tube. A CONCHIFERA. 505 The common piddock is used for bait on the Deven coast; its footis white and translucent when fresh, like a piece of ice; the hyaline stylet (p. 22) lodged in it, is large and curious. P. costata i3 sold in the market of Hayannah, where it is an article of food. P. dactylus has two accessory valves to protect the umbonal muscle, with a small transverse plate behind; a long unsym- Fig. 269. Pholas dactylus. Chalk, Sussex Coast. u, umbonal valves; », post-umbonal valve; d, dorsal valve. metrical plate fills up the space between the valves in the dorsal region. P. candida and parva have a single umbonal shield, and no dorsal plate; these differences are only of specific value. In P. crispata; Li. (Zirfeea, Leach), the umbonal shield is not dis- - tinctly calcified, but there is a small posterior plate; the surface of the valves is divided into two areas by a transverse furrow Distribution, 32 species. United States, Norway, Britain, Western Africa, Mediterranean, Crimea, India, Australia, New Zealand, Western America :—25 fathoms. : Fossil, 25 species. (U. Lias—) Eocene—. United States, Europe. The secondary species belong to the next group. PHOLADIDEA, Turton, 1819. Type, P. papyracea, Pl. X XITI., Fig. 20. Shell globose-oblong, with a transverse furrow ; anterior gape large, closed in the adult by a callous plate; 2 minute accessory valves in front of the beaks. Animal with a fringed disk at the end of the combined siphons, and a horny cup at their base. Distribution, 7 species.“ Britain, New Zealand, Ecuador. Low tides—10 fathoms. Sub-genera, Martesia (Leach), Bl. 1825. M._ striata, Pl. XXIII, Fig. 21. Valves lengthened behind, when full grown, by a plain border; umbonal valves 1 or 2; dorsal and ventral margins often with narrow accessory yalyes. 11 species. West Indies, Africa, India. JZ. striata burrows in hard timber. Z 506 MANUAL OF THE MOLLUSCA. M. terediniformis was found in cakes of floating wax on the coast of Cuba. (G. B. Sby.) IZ. australis in (fossil 7) resin, on the coast of Australia. JZ. rivicola in timber twelve miles from the sea, in Borneo. J. scutata, Kocene, Paris, lines its burrow with shell. ; Jouannetia (semicaudata),, Desm. (Pholadopsis, Conrad ; Triomphalia, Sby.) Shell very short, sub-globose; right valve longest behind; anterior opening closed by a callous plate deye- loped from the left valve overlapping the margin of the right valve, and fixed to the single unsymmetrical umbonal plate. Distribution, 4 species. Philippines, Western America. Jossil, Miocene —. France. . Parapholas, Conrad, P. bisulcata, Pl. XXIII. , Fig. 22. Valyes with 2 radiating furrows. Distribution, 4 species. Panama, Torres Straits. XYLOPHAGA, Turton. Hiymology, xulon, wood, phago, to eat. _ Types, X. dorsalis, Pl. XXIII., Fig. 23; X. globosa, Sby. Valparaiso. Shell globular, with a transverse furrow; gaping in - front, closed behind : pedal processes short and curved; anterior margins reflected, covered by 2 small accessory valves ; burrow oval, lined with shell. Animal included within the valves, except the slender con- tractile siphons, which are furnished with pectinated ridges, and divided at the end; foot thick, very extensile. Distribution, 2 species. Norway, Britain, South Aiaebban: Bores an inch deep, and across the grain, in floating wood, and timbers which are always covered by the sea. TEREDO (Pliny), Adanson. Type, T. Norvegica, Pl. XXITI., Figs. 26, 27. Synonyms, Septaria, Lamarck. Hyperotis, Guettard. Shell, globular, open in front and behind, lodged at the inner extremity of a burrow partly or entirely lined with shell ; valves 3 lobed, concentrically striated, and with one transverse frit F hinge-margins reflected in front marked by the anterior muscu- lar impressions; umbonal cavity with a long curved muscular process. Animal worm-like ; mantle-lobes united, thickened in Holt. witha minute pedal opening; foot sucker-like, with a foliaceous border; viscera included in the valves, heart not pierced by the intestine; mouth with palpi; gills long, cord-like, extending CONCHIFERA. 507 into the siphonal tube ; siphons very long, united nearly to the end, attached at the bifurcation and furnished with 2 shelly pallets or styles ; orifices fringed. T. Navalis is ordinarily a foot long, sometimes 24 feet; it destroys soft wood rapidly, and teak and oak do not escape; it spy ee Py ay Yi costperaagad S) ee | Fig. 270. Ship-worm, Teredo Norvegica, removed from its burrow. always bores in the direction of the grain unless it meets the tube of another Teredo, or a knot in the timber.* In 1731-2 it did great damage to the piles in Holland, and caused still more alarm ; metal sheathing and broad-headed iron nails have been found most effectual in protecting piers and ship-timbers. . The Teredo was first recognised as a bivalve mollusc by Sellius, who wrote an elaborate treatise on the subject in 1733. (Forbes.) T. corniformis, Lamarck, is found burrowing in the husks of cocoa-nuts and other woody fruits floating in the tropical seas; its tubes are extremely crooked and contorted, for want of space. The fossil wood and palm-fruits (Nipadites) of Sheppy and Brabant are mined in the sameway. The tube of the giant Teredo (7. arenaria, Rumph. Furcella, Lamarck) is often a yard long and 2 inches in its greatest diameter; when broken across it presents a radiating prismatic structure. The siphonal end is divided lengthwise, and sometimes prolonged into two diverg- ing tubes. 7’. Norvegica and 7’. nana are divided longitudinally and also concamerated by numerous, incomplete transverse partitions at the posterior extremity. T. palmulata (Xylotrya, Leach) has the siphonal pallets elon- gated and penniform (Pl. XXIII., Fig. 28); a species with similar styles occurs in the fossil wood of the Greensand of Blackdown. . Distribution, 21 species. Norway, Britain, Black Sea; Tro- pics :—119 fathoms. ‘ Fossil, 24 species. Lias—. United States, Europe. Sub-genus. Teredina, Lamarck. T. personata, Pl. XXIIL., Figs. 24, 25. Hocene, Britain, France. Valves with an acces- sory plate in front of the umbones ; free when young. The _ tube is sometimes concamerated; its siphonal end is often truncated; and the opening contractéd by a hning which makes it hour-glass shaped, or six-lobed (Fig. 25 a.). * The operations of the Zeredo suggested to Mr. Brunel his method of tunnelling the Thames. INDEX. The synonyms are printed in ztalics, and the pages where the genera are described are Abbreviations, 49. Abra, 483. Abralia, 171. Acanthina, 223. Acanthochites, *284. Acanthodoris, *332. Acanthopleura, *283. Acanthoteuthis, #175 Acanthothyris, 375. Acardo, 323, 454. Acavus, *289. Acephala, 5. Acera, *316, 319. Achatina, *292. Achatinella, #292, Acicula, #310. Aciculide, *310. Aclesia, *321. Aclis, *240. Acmeza, #281, Acmaed, 311. . Acme, 311. Aceeli, *174. slcostead, 435, Acroculia, 277. Acrolorus, 302. Acrotreta, #390. Act@on, 313, 339, Acteonella, #314, Acteonia, *339. Acteonina, *314, Actinocamaz, 175. Actinoceras, *191. Actinoconchus, 373. Actinocyclus, *329. Actinodonta, 432. Acuarii, #174. Acus, 220. Adacna, *454. Adamsiella, #308. Adductor impressions, 401. Adelopneumona, 285. Adeorbis, *266. Admete, 55, *216. AZgear Sea Shells, 67. Atgirus, 327, #330, ABnigma, 408. : ABolide, *335. aban ZEolis, 328, ¥335. 4Estivation, 13, /Ktheria, *435. Affinities, 45. as indicated by an asterisk (*). African region, 97. Aganides, 196. Agaronia, *227. Agina, 490. Alasmodon, 433. Alcadia, #310. Aleynus, 265. Alderia, *338. Aleutian province, 7 Alexia, #305. Alicula, 316. Allorisma, 496, 498. Alvania, 240. Amalthea, #278. Amalthei, *198. Amathina, *277. Ambonychia, *417. Amicula, 284. Ammonites, 35, 37, *197. Ammonitide, *195. Amnicola, *247. Amoura, 239. Amphibola, *259. Amphibulima, 290. Ampluceras, 234. Amphicheena, *486. Amphidesma, 431, 483, 497. Amphidonta, 407. Amphipeplea, *301. Amphisphyra, *317. Amphorina, 335. Ampulina, 236. Ampullacera, 259. # Ampullaria, 14, *258. Ampuitina, 310. Amusium, 411. Amusium, *412. Anadenus, *296. Analogies, 45. Anapa, *485. Anastoma, *289, Anatina, #495. « "< a7; 2. - Anatina, 431. ‘Anatinella, *479. Anatinide, *494, ‘ Anatomus, 269. ‘Ancillaria, 24, *227, Ancistrochirus, 171. ‘Ancistroteuthis, 171. Ancula, 327, *331. Anculotus, 247. Ancyloceras, *200. Ancylus, 287, *302. Aneitea, *297. Anisoceras, 200. Annulati, *199. Annulosa, 2. Anodon, 30, *434. Anolax, *220. : Anomalocardia, 424, 473. Anomia, 19, *408. Anoplomya, 496. Anoplotheca, #379. Anops, 342. Anthracosia, #470. Antigone, 473. Antilles, shells of, 110. . Antiopa, *337. Aperostoma, 308. Aperture, 206. Apex, 205. Apioceras, 193. Aplexa, 302. Aploceras, 194. » Aplustrum, *318. Aplysia, 11,22, 23, 24,*320. Aplysia, 321, Aplysiadee, *320. Aporrhais, 211, *244. Aptychus, 182. Aquiferous system, 24. Arabian shells, 98. Aralo-Caspian prov., 68. Arca, 30, 395, *424, Arcadee, *424, Architectoma, 253. Arcinella, 437, 471, 502. Arcomya, 497. Arctica, 464. + Arctic province, 57—59. Areopagia, 480. Argonne region, 114° Argiope, *368. rd pe 28, 31, 39, 56, *161, Argus, 411. Arietes, *198. Arion, *296. Ariophanta, *290. Armati, #198. Artemis, *474. Articulated operc., 208. Ascoceras, 189. Asiphonida, 406, Asolene, *259. ~ Aapergillum, 55, #503. Assiminea, 256. Astarte, 33, 55, *464, Astartela, 469. Asteronotus, #329. Atagema, *529. Athoracophorus, 297. Athyris, *373. Atlanta, 29, 341, #314. Atlantide, *343. Atlas, *320. Atrypa, *378. Aturia, *189. Atys, 316. Aucella, *416. Aulonotreta, 392. Aulopoma, 308. Aulosteges, #385. Aulus, 482. . Auricella, 305. Auricula, *304. Auriculide, 36, *303. Auriscalpium, 495. Australian region, 103. Australian shells, 74, Avellana, 314. Avicula, 30, #415. Aviculidz, *415. Aviculo-pecten, *417. Axinus, *431. Axis of shell, 205. Azara, 490. Azeca, *292. Azores, shells of the, 65, 94 Bachybathron, *225. Bactrites, *197. Baculites, *201. Bakewellia, *418. Bailantium, 349. Balea, *293. Balearic Isles shells, 92. Baphia, 433. Barbatia, 424. Barnea, 504. Base of shell, 206. Baitillus, 263. Batissa, #463. Bela, *229. Belemnitella, *175. Belemnites, *173. Belemnitide, *173. Belemnosepia, 168. Belemnosis, *177. Belemnoteuthis, *175. Bellerophina, *345. Bellerophon, *344, Belopeltis, 168. Beloptera, *177. Belosepia, 177. Beloteuthis, *168, Berthelila, 322. Bezoardica, 224, * Biapholius, 502. . Bifrontia, *253. __ Biradiolites, #448. ee INDEX. Birostrites, 447. Bithynia, 33, *258. Bittium, *242. Black Sea shells, 67. Body whorl, 206. Bolitzna, *166. Bonellia, 240. Bontia, 495. Boreal province, 60, 61. Boring, 394. Bornean shells, 102. Bornella, *333. Bornia, 459. Borsonia, *229, Bostrychoteuthis, 165. Bouchardia, *366. Bourciera, 307. Brachionobranchia, 5. Brachiopoda, range in time, 128 Brachiopoda shell, 32. Brachychlamis, *332. Brachydontes, 421. Brachypus, 293. Branchia, 26, Brazil, shells of, 112. Brocchia, 277. Brochus, 249. Broderipia, *267. Brownia, *284, Bucardium, 467. Buccinanops, 220. Buccinidee, *218, Buccinulus, *318. Buccinum, 55, *219. Buchanania, *299. Buckie, 218. Bulimulus, *291. Bulimus, 15, 32, 36, 37, 44, 111—113, *291, Bulin, 301. Bulinus, 291. Bulla, *316. Bulla, 315. Bullea, 318. Bullia, 220. Bullidz, *315. Bullina, 317, 318. Bullinula, 318. Bursatella, 321. Lusiris, *321. Dysso-anodonta, 434, J? ysso-arca, 424. Byssomya, 502. Byssus, 19, Czcum, *249, Calcar, 264. Calcarella, *284. Calceola, *883. Californian province, 78. California, shells of, 109, Callia, 309. Calliopewa, *336. Callo-chiton, 283. 4 Callopoma, 263. Calma, *337. Calpurna, *234. Calpurnus, 234. 509 Calypeopsis, *276, Calyptraa, *276. Calyptreidze, *275. Camarophoria, *376. Cameroceras, *191. Camptoceras, *302, Campulites, 194. Campulote, 224. Campyloceras, 194. Canadian region, 106. Canal, 206. Canaliculati, *174. Canary Isles shells. 65, 94 Cancellaria, 55, *216. Canthiridus, 265. Cape region, 97. Capisterium, 485. Caprella, 291. Capricorni, *198, Caprina, *450. Caprinella, *448.- Caprinula, 448. Caprotina, *451. Capsa, 481, 486. Capsula, *481. Capulus, 277. Carbonicola, 470. Cardiade, *453. Cardiapoda, *243. Cardilia, *46y. Cardinalia, 264. Cardinal teeth, 401. Cardiocardita, 471. Cardinia, *470. Cardiola, *417. Cardiomorpha, 467, *498. Cardissa, 454. Cardita, *471. ‘Cardium, *453. Carimaria, 9, 12, 29, 341, *343, Carinaroides, 343. Carocolla, *289, Carolia, *410. Cartilage, 400. Carychium, *30d. Casella, *332. Cassiani, *199. Cassidaria, *225. Cassidula, 217, 304. Cassis, 32, 38, *224, Castalia, *434. Catantostomata, *270. Cataulus, *309. Catillus, 419. Cavolina, *335. Cavolina, 348. Celtic province, 61—63. Cemoria, 274. Cenia, *339. Cepa, 408. Cepatia, 235. Cephalopoda, 4, 27, 155. Cephalopoda, range in time, 127. Ceratisolen, *487.- Ceratites, *197.° Ceratosoma, *331, Cercomya, *495, 510 Ceriphasia, *24 7%, Cerithiadee, *242. Cerithidea, 36, *243. Cerithiopsis, *242 Cerithium, *242. Cernina, *236. Ceromya, 467, *497. Ceronia, *485. Cerophora, 342. Ceylonese shells, 100. Cheena, *501. Chalidis, 340. Chama, 38, 131, *437. Chamida, *437. Chamostrea, *500. Cheiroteuthis, *170. Cheletropis, 212, 352. Chelidonura, *319. Chemnitzia, *239. Chenopus, 245. Chili, shells of, 114. Chilinia, *301. Chilostoma, *247. Chinese snails, 101. Chione, 473, 485. Chiorera, *338. Chironia, 459. Chiton, 23, 28, *282, Chitonellus, *28-L. Chitonide, *282, Chlorostoma, 264. » Choanopoma, *307, 308. Chondropoma, 307. Chondrosepia, 168. Chonetes, *326. Choristites, ol. Choristodon, 476. Chorus, 223. Chromodoris, *329. Chrysodomus, 55, *218. Cilia, 42 Cingula, 255. Cinulia, *314. Cionella, 292. Circe, *464, Circulatory system, Brach- iopoda, 358. Cirroteuthis, *165, Cirrus, *27 e Cistopus, 163. Cistula, *307. Cithara, *229, Clanculus, 265. Classification, 45. Clausilia, 37, 286, *294. Clausina, 456. Clavagella, *502. Clavati, *174. Clavatula, *229, Clavella, *218. Clea. 247. Cledophorus, 468. Cleidotherus, 500. Cleiothyris, 373, 378. Clementia, *475. Cleobis, 469. Cleodora, 347, *3849. Clepsydra, 503. Cliidz, *353. INDEX. Climate, inf. of,on dist.,53. Clio, *353. Clio, 349, Cliodita, *353. Cliona, 34. Clione, 353. Clionella, *229. Clelia, 336. Clymenia, *190. Coccoteuthis, 168. Cochkdium, 217. Cochlitoma, 292. Cochlodesma, *495. Cochlodina, 294. Cochlohydra, 290. Codakia, 456. Coelenterata, 2. Coleoprion, *350, Collar of mantle, 24. Collecting shells, 136. Collonia, *266. Colour of shells, 38. Columbella, 55, *226. Columbian region, 111. Columbinella, 227, Columella, 205. Columna, 292, Colus, 218. Cominella, 219. Concentric operc., 207. Conchifera, 5, 393. Conchifera, range in time, 128. Concholepas, *222. Congeria, 423. Conide, *228. Conocardium, *454. Conoceras, 190. Conoheliz, 216. Conorbis, 228. Conoteuthis, *176. Conotubularia, 192. Conovulus, *304, Conradia, *253. Conularia, 2, 346, *350. Conus, 12, 24, 32, 33, 36, 55, *228. Coralline zone, 152. Coralliophaga, *468. Corbicula, *462. ee *457. Corbula, 457, 490, 491. Corbulomya, 490. Corephium, 284. Coret, 302. Corimya, 495. Coriocella, 237. Corniculina, 249. Coronati, *199. Corsican snails, 92. Coryphella, *335. Couthouyia, *253. Cranchia, *169. Crania, 42, *386. Craniade, *386. Craspedopoma, *309. Crassatella, 55, *466, Crassina, 464. Crenatula, *418, Crenella, 43, 55, *422. Crepidula, *276, Creseis, *349, Creseis, 350. Crimora, *332, Crioceras, *199. Criopus, 386, Cristati, *198. Crossostoma, *266. Crucibulum, *276. Crypta, 277. Cryptella, 297. Cryptina, 431. Cryptocella, *238, Cryptoceras, *189, Cryptochiton, 284. Cryptoconchus, 284. Cryptodon, *456. Cryptogramma, 474. Cryptophthalmus, *316, Cryptostoma, 236. Crystalline stylet, 22. ~ Ctenoconcha, 429, Ctenodonta, 427. Cucullea, *425. Cucullella, *427, Cultellus, *487. Cuma, *222. Cumingia, *483, Cuneus, 474, 485. Curtonotus, *431. Curve of shells, 204. Cuspidaria, 491, Cuthonia, *337. Cuttle fish, 8. Cuvieria, *349. Cyamium, *458, Cyathodonta, 495. Cycladide, *461. Cycladina, 459. Cyclas, 15, 29, 397, *461. Cyclidia, 182. Cyclina, *475. Cycloceras, 190. Cyclonassa, 221. Cyclophorus, *308. Cyclostoma, 266. Cyclostoma, *306. Cyclostomidee, *306. Cyclostrema, *266, Cyclothyris, 375. Cyclotopsis, 308. Cyclotus, *308, Cylichna, *317. Cylindra, *231. Cylindrella, 36, *293. Cylindrites, *313, Cyllene, *221. Cymba, 28, *231. Cymoba, 278. Oynbicts, 230. Cymbulia, *351. Cymodocea, *354. Cynodonta, 216. Cypreea, 12, 24, 32, 35, 37, 55, *232. ee TCUSS*S, 2246 Sora #239, Cypricardia, *.€3 ‘ ‘ 1 et on A _ 1» ro ees Cypricardites, 422, 468. Cyprina, 33, 55, *463. Cyprinide, *463. Cyprovula, *233. Cyrena, *462. Cyrenella, 463. Cyrenoides, *463. Cyrtia, *372. Cyrtoceras, *194, Cyrtodaria, 493. Cyrtolites, *345. Cyrtulus, 218. Cytherea, 473. - Dactylina, 504, Dactylus, 313. Daphnella, 229. Daudebardia, *290. Davidsonia, *382. Davila, *485. Decapoda, *166. Decollated shells, 36, 206. Defrancia, 229. Delphinoidea, 256. Delphinula, 266. Deithyridea, 365. Delthyris, 371. Dendrodoris, 328. Dendronotus, 327, *334. Dendrostrea, 408. Dentaliade, *282. Dentualium, 27, *282. Dentati, *198. Dentition, 208. Dentition formula, 401. Deridobranchus, *268. Dermi-branchiata, 339. Deshayesia, *236. Desmoulinsia, 221. Development, 41, 287, Diacria, 348. Diadora, 274. Dianchora, 414, Diaphana, 317. Dibaphus, *216. Dibranchiata, *156. Diceras, *439. Dicelosia, 380, Didacna, 454. Digitaria, 465. Dimya, 408. Dimyary, 402. Diodonta, 481. Dione, 474. Dicecious, 40, Diphyllidia, *325. Dipilidia, 438, Diploceras, 192. Diplodonta, 455, *458. Diplommatina, *309. Disci, *198, Discina, 357, *388, Discinide, *388. Discites, *189. Discites, 411. Discohelix, 253. Discosorus, *193. Dispotea, 276. Dithyra, 393. INDEX. 7 Ditremaria, 271. Dolabella, *321. Dolabra, 431. Dolabrifera, *321. Dolium, 36, *225. Dombeya, 301. Donacilla, 485. Donacina, 486. Donax, *485. Doride, *328. Doridium, *319. Doris, 14, 24, 327, *328. Dorsanum, 220, Dosidicus, *173. Dosinia, 474, 475. Doto, 334. Dredging, 140. Dressena, 37, *423, Drillia, *229. Eburna, *221. Ecculiomphalus, *345. Echinospira, 285. Edmondia, *498. Egeria, 485, 486. Eggs, 40. Eylisia, 248. Fxdothea, 319. Elasmatina, 294. Electrina, 310. Eledone, 27, *165. Elenchus, 12, *265. Elysia, *839. Elysiade, *339. Emarginula, *275. Embla, 491, Embletonia, *336. Embryo, 44. Encephala, 3. Endemic species, 51. Endoceras, *192. Endosiphonites, 190. Enida, 265. Enoplo-chiton, 284 . Enoplotetthis, *171. Fnsatella, 487. Ensis, 487. Enieletes, 380. Entodesma, *499. Enzina, 214. Eolis, 23, 40. Epidermis, 33, 400. Epiphragm, 288. Lythyris, 363. Erato, *234. Erodona, 490. ' Ervilia, *485. Erycina, 459, 473, 483, 484. Eryz, 484. Escutcheon, 400. Eubranchus, 335. Eucharis, *492. Eudesia, 365. Eulima, *240. Eulimella, *239. Eumenis, 334, Euomphalus, 36, *267, 346. DLuphemus, 344. Euplocamus, 331. Eurybia, *350. Eurydesma, *417. Eurydice, 338. Euthria, 214. Eutropia, 263. Exogyra, *408. Eyes, 16. Facelina, *335. Falciferi, #198. Families, 46. Farcimen, 309. Fasciolaria, *215. Fastigiella, *244. Faunus, 248. Favorinus, *337. Felania, 458. Fenestrella, 408. Ferussina, 308. Fibrous shells, 51. Ficula, 217. Filurus, *337. Fimbria, 333, 457. Fimbriati, +199. Fiona, *336. Firola, 9, 341, *342. Firolide, *342. Firoloides, *342, Fissirostra, 365. Fissurella, 27, *272. Fissurellide, *272. Fissurellidea, *273. Fistulana, 35, 501. Flabellina, *335. Food, 8, 9. Formation of shells, 34, Forms of shells, 56. Fossarus, 131, *253 Fragilia, 481. _ Fryeria, *825. Fucola, 339. Fulgur, *217. Funnel, 187. Fusulus, 293. Fusus, 29, 35, 37, *218. Fusus, 212. Gadinia, *281. Galapagos Islands, 112. Galapagos Isles shells, 8Q Galatea, *486. Galeomma, *461, Galerus, 276. Galvina, #337. Ganglia, 16. : Gari, 482. Gasteropoda, 4. Gasteropoda, time, 128 Gastrana,.*481. Gastrana, 476. Gastridium, 219. Gastrocheena, *501. Gastrochenidee, *500. Gastroceeli, *174 Gastroplax, 323. Gastropteron, #319 Gellina, 334 . Gena, *267. | St range in 512 Genera, 46, 52. Generic areas, 52, 53. Genetic aflinity, 45. Geographical cist., 50. Geological strata, 118. Geomalacus, *296, Geomelania, *311, Geoteutizis, *168. Geotrochus, *289, Geovula, 304. Germanic region, 89. Gervillia, *418, Gibbula, *265. Gibbus, #291. Gizzard, 22. Glandina, 286, *292. Glaucomya, *477. Glauconella, 316. Glauconome, 477. Glaucus, *336. Globiconcha, *314. Globulus, *236. Glossodoris, #329, Glossus, 467. Glottella, 247. Glycimeris, 55, *493. Gnathodon, *478. Goldfussia, *469. Gomphoceras, *193, Gonambonites, 380. Gonatus, *168. Goniatites, #196. Gonioceras, 190. Goniodoris, *330. Goniomya, *497. Goniophora, 468. Goodaillia, 464. Gouldia, *465. Grammysia, *497. Grateloupia, *474. ' Gresslya, *497. Growth of shell, 34. Gryphea, 35, *408. Gryphochiton, 284. Gryphus, 363. Guard, 173, 174. Gulf-weed banks, 64. Gundlachia, *303. Gymnodoris, *332. Gymnosomata, *353. Gypidia, 377. Halia, *220. Haliotide, #268. Haliotis, 24. 27, *268. Halobia, 417. Galopsyche, 350. Haminea, 316. Hamites, #201. Hamulina, 201. Harpa, 55, *226. arpula, 230. Harvella, *478. Hastati, *174.. Head, 42, Heart, 24, 42. Hectocotyle, 159-163, Flecuba, 485, Helcion, 278, % ERS 7 i) INDEX, Hlelicarion, 290. Tielicella, *289. Helicerus, *178. Helicidee, #288. Helicina, *300. Flelicina, 265. Helicoceras, *200. fMelicocryptus, 253. Helicolimar, 290. Heliconoides, 352. Helicophanta, 290. Helicophlegma, 344. flelicteres, 292. flelisiga, 299. Helix, 11, 14, 33, 35, 37, *238. Helix distribution, 87. Helminthochiton, 284, Hemicardium, *454. Hemicyclonosta, 469. Hemidoris, 328. Hemimitra, 247. Hemipecten, *412. Hemiplacuna, 410, Hemiproniteés, 380. Hemisinus, #247. Hemithyris, 375. Hemitoma, *274. Heptabranchus, *329. Hermea, 338. Heteroceras, #200, Heterofusus, 352. Heterogangliata, 2, Heterophylli, 199. “Heteroteuthis, 170. * Hettangia, 457, Hexabranchus, #329, Fiantula, 273. Fiatella, 461, 502. Hinge line, 401. Hinnites, *412. HHippagus, 472. Hipparionyx, 378. Hippochrenes, 212, Hippomya, *423.+ Hipponyx, 7, *278. _| Hippopodium, *471. Hippopus, *453. Hippurites, 32, *443, Hippuritidee, *440. HAirundinella, 319. Histioteuthis, *170. Holopea, *272. Holostomata, *234, Homogangliata, 2. Homoiozoic belts, 54. Homologies of shell, 39. Homomya, *496. Hoplomytilus, *423, Hortolus, 189. Humphreyia, *508. Huronia, *191. Hyaleea, *348. Hyaleide, *348, Hyalina, *232. Hyaloteuthis, 172. Hybernation, 39, 40. Hybocystis, #309. Hybrids, 46. Hydatina, 318. Hydrobia, *256. Hydrocena, 307. Hypolites, 191. Hy perotis, 506. Hypobranchea, *325. Hypodema, 383. Hypogea, 487. Hypostoma, *289. ‘Hypothyris, 375. Hypotrema, *418, Hyria, *434, flysterolites, 379. Ianthina 23, 31, *271. Icarus, *322. Ichthyosarcolites, 450. Idalia, *331, Idotaa, 457. Imbricaria, *231. Imbricated opere., 207. Imperator, *264. Imperforate shells, 205. Impregnation of ego, 41. Incilaria, *296. Indian region, 99. Indo-Pacific province, 7k Infero-branchia, 312. Infundibulum, 264, 276. Ink bag, 157, 173. Tnoceramus, 31, #419. Inoceramus, 491. Inoperculata, 285. Integro-pallialia, #436. to, 247. - Iphigenia, *486. Ischnochiton, 283. Isidora, 301. Ismenia, *868. Isoarca, *427, 467, Tsocardia, #466. Lsocardia, 431. Jsodonta, 478, 486. Lsognomon, 418. Itieria, 314. Jamaica, skells of, 110. Jamaicia, 307. Jaminea, 239. Janella, *297. Janus, 337. Japanese snails, 101. Japonic province, 75. Jasonilla, 285. Javanese shells, 102, Jeffreysia, *256. Jouannetia, *506 Kailceno, 175, Katharina, #284. Kellia, #459. Kingena, *368. Kleinella, *317. Koninckia, *381. Kraussia, *367. Labio, 265. Lachesis, *229, Lacuna, 55, *255, - Ladas, 344. . Leevigati, #189, Lagera, 216 Lajonkairia, 475. Lamellaria, *237. Lamellibranchiata, 5, 393. Laminarian zone, 151. Lampania, *244, ' Lampas, 363. Land provinces, 51. Laniogerus, 336. hanistes, *259. Lanistes, 422. Lasea, 459. Lateral teeth, 401. Laternula, 495. Latia, *302. Latirus, 216. Latona, 485. Latrunculus, 221. Leachia, 170. Leda, 427. Leguminaria, 488. Leila, 435. Leiodomus, 220. ‘Leiostoma, 218. Lembulus, 427. Leonia, 306. Lepeta, *281. Leptena, 380, 381. Lentagonia, 380. Lepto-chiton, 283. Leptoconchus, 224. Leptodonus, 497. Lepton, *460. Leptopoma, *308. Leptoteuthis, *169. Leucostoma, 223. Leucotina, *241, Leucotis, 237. Levenia, 224, Liarea, 307. Libitina, 467. ; Ligament, 400. Ligati, *199. Ligula, 484, 495. Liguus, 292. Lima, 11, *412. Limaceila, 296. Limacide, *295. Limacina, *351. Limacinide, *351. Limea, *413. Limanomia, *409. Limapontia, *340. Limatula, *413. Limax, *295. Limnea, *300. Limnzide, *300. Limopsis, *426. Lincina, 307. Lines of growth, 34. Lingual teeth, 21. Linguella, 325. Lingula, 1, 358, 359, *390. Lingulide, *390, Linteria *316, Liotia, +266. Lips, 206. INDEX. Listera, 484. Lithedaphus, 276. Lithidion, 306. Lithocardium, *454. Lithodomus, 34, *422. Lithoglyphus, *257. Litiopa, 8, *255. Littoral zone, 151. - Littorina, 37, *250, 286. Littorinidz, *250. Lituites, *189, Lituus, 174. Liver, 22. Livona, 264. Lobaria, 482. Lobiger, *322, Loligo, *167. Loligopsis, *170. Laligosepia, 168. Lotiolus, 168, 172. Lomanotus, *334. Lomastoma, *309, Lophocercus, 222. Lophurus,:283. Loripes, 456. Lottia, 281. T.oxonema, *241. Lucapina, *273. Ducidella, *310. Lucina, 38,56, *456. Lucinide, *455. B Lucinopsis, 131, *475. Lunatia, *236. & Lunularca, *427. Lunulocardium, 454. Luponia, *233. Lusitanian region, 91—97. Lusitanian proy., 63, 67. Lutraria, *479. Lutricola, 484. Lychas, 454. Lychuus, *289. Lyonsia, 422, 498. Lyra, *365. Lyriodon, 430. Lyrodesma, *432. Lysianassa, 497. Macgillivrayia, 225, 352. Macha, 488. Machera. *488. Maclurea, *345. Macrocheilus, *241. Macrodon, *425. Macroschisma, *273, Mactra, 24, *477. Mactra, 431. Mactrella, *478. Mactride, *477. Mactrinula, 478. Mactromya, 457, 484, 496. Madagascar shells, 98. Madeiran shells, 65, 92, Maeonia, 468. Magilus, 36, *224, — ims) 513 Malea, *226. Malletia, 429. Malleus, *416. Mamilla, 235. Mangelia, *229. Mangelia, 229. Mantle, 34. Margarita, 55, *265. Margaritana, 433. Margaritophora, 416. Marginella, 55, *232. Marine provinces, 51, 54 Marinula, 304, Marisa, *259. Marmorostoma, 263. Marsenia, 237. Martesia, *505. Martinia, 371. Mauritius shells, 99. Mediterranean shells, 65. Medoria, 255. Megadesma, 486. Megadesmus, 470. Megalodon, *469. Megaloma, *469. Megalomastoma, 809. Meganteris, #365. Megasiphonia, 189. Megaspira, 286, *294. Megathyris, 368. Megatrema, 278. Megerlia, *367. Meghimatium, 296. Meladomus, *259. Melafusus, *247. Melampus, 304, Melanatria, *247. Melania, *246. Melaniade, *246. Melaniotdes, 240. Melanopsis, 33, 37, *248. Melatoma, *247. Meleagrina, *416. Melia, 191, 195. | Melibcea, #334, Melina, 418. Melo, 231. Menestho, 240. Merceneria, 473. Meretrix, 474. Merista, *374. Meroe, *474. Merria, 237. Mesalia, 249. Mesodesma, *484. Metoptoma, *277. Metropolis, 52. Mexico, shells of, 109. « Minolia, 265. Miranda, 331. Mitra, 53, *231. Mitrella, 231. Modiola, 11, 33, *421. Modiolarca, *422. Modiolaria, 422, °— Modiolopsis, *422, ° Modulus, *252. Molluscoida, 5, 6 Monilea, 264. ae 2 4 4 514 Monoceros, *223, Monocondylea, *434, Monodacna, 454. Monodonta, *265. Monececious, 40. Monomyary, 402. Monopleura, *438. Mono-pleuro-branchiata, 312 Monoptigma, *240. Monoptigma, 239. Monoptygma, 313. Monotis, *417. Monstrosilies, 37. Montacuta,*460. Montagua, 335. Mopalia, 284. Morio, 225. Motrrisia, *367. Morum, 225. Mouretia, 281. Mulinia, 477. Maulleria, 432, *435. Multispiral operc., 208. Munsteria, 182. Murchisonia, *270. Murex, 23, 35, 36, *213. Muricide, *212. Muscular system, 18, 355, 401. Muscutium, 461. Mutela, 435. Mya, *489. Myacidee, *489. Myacites, *497. Myadora, *499. Myalina, *421, Myatella, 498. Mycetopus, *435. Mycetopus, 435. Myochama, *499. Myoconcha, *471. Myonia, *241. Myoparo, 427. Myophoria, *431, Myopsis, 497. Myrina, *423. Myristica, *217. Mysia, 475. Myliita, 459. Mytiticardia, 471. Mytilide, *420, Mytilimeria, *422. Mytilomya, 423. Mytilus, 30, 31, 43, #420, Myzxostoma, 308. Vacca, 235. Nacella, *280. Nacreous shells, 29, Nanina, 290. - Naranio, 476, Narica, *237. Nassa, *221. Natica, 88, #235. Naticella, 236. Naticidee, *235. Pe ad i Naticopsis, *235, INDEX. Natural barriers, 53. Naiural history provinces, 50—54. Nautilide, *185. iVautiloceras, 194. Nautilus, 161. Nautilus, 55, 185. Navicella, *262, Nera, *491. Neda, he S255 Neilo, 429. Neithea, *412. Nematura, *256. Nerinea, *244, 314. Nerinella, *244, Nerita, 38, 55, *260. Neritidee, 36, *260. Neritina, 37, *261. Neritoma, *261. Neritopsis, *261. Nervous system, 16. Nets, 139. Neverita, 236. New Zealand shells, 104. Nidamental ribbon, 40. Niphonia, 267, Niso, *240, WNoetia, 427. Nomenclature, 48, Northia 221. Notarchus, *321. PN othoceras, *195. Notoceeli, *174. Notomya, 469. Novaculina, *489, Jucinella, 427. Nucleobranchiata, 340, Nucleus, 205. Nucula, *426. Nucula, *497. Nuculina, *427. WNucunella, 427. Nudibranchiata, *825. Ps Obeliscus, 238. Obolus, *392, Octopoda, *158. Octopodoteuthis, 171. Octopus, 56, *163. Ocythoe, 161, Odoncinetus, 495. Odontidium, 249. Odontostomus, *291. Odostomia, *229. Oleacina, 292. Oligyra, 310. Oliva, 32, 55, *227 Olivancillaria, 227 Olivella, *227, Olivia, 265. Omaila, 480. Omalacxis, 253. Omalia, 475. Omalonyx, *291. Ommastrephes, *172. Omphalotropis, 307. Oncidiade, *299. Oncidium, *299. Oncidoris, *829. Oncoceras, *193, Oniscia, #225. Onustus, 254. Onychia, 171. Onychochi‘on, 284. O. ychoteu_his, *171. Operculata, *305. Operculum, 38, 182, 237. Ophileta, 267. Opis, *470. Opistho-branchia, *311, Opisthophorus, *309. Orbicelia, 389. Orbicula, 358, 386, 388. Orbiculoidea, 388. Orbis, *253. Orbulites, 187. Oregon, shells of, 109. Ormoceras, *191. Ornati, *198, Orthambonites, 380. Orthide, #379, ° Orthis, *380. Orthisina, *380. Orthoceras, 38, *190. Orthoceratide, *190. Orthona, 336. Orthonotus, *423. Orthothriz, 385. Oscanius, 322. Osteodesma, 495. Ostrea, 31, *407. Ostreidze, *407. Otina, *238. Otolithes, 17. Otopoma, *307. Oviducts, 359. Oviparous repr., 40, Ovulum, 27, *234. Ovum, 41. Owenia, 169. Oxygyrus, *344. Oyster shell, 51. Pachydomus, *469. Pachylabra, 258. Pachymya, 492. Pachyodon, 434, 470. . Pachyotis, 291. Pachyrisma, *470, Puchytes, 414. Puchytoma, 310. Pacyodon, 490, — Padollus, 268. Pagodella, 252. Palteoteuthis, 177, 182. Pallial impression, 20. Pallial line, 404. Pallial sinus, 404. Pailio-branchiata, 354. Pallium, *412. Paludestrina, 254, Paludina, 27,37, *257, 286, Paludinella, 256. Paludinide, *257. Paludomus, *247. Panama shells, 81. Panamic province, 79. Pancreas, 23. Ses P; . / Pandora, *499. Pandorina, 498. Panopea, 53, *492. Paphia, 464, 465, 475, 484. Papuan shelis, 103. Papyridea, 453. Parallelopipedum, *425. Parapholas, *506, Parmacella, *297. Parmarion, *297. Parmophorus, *274. Parthenia, 239. Parthenopea, 461. Partula, 291. . Pasithea, 240. Patagonian province, 83. Patagonia, shells of, 115. Patella, *278. . Patella, 391. Patellide, *278. Patelloidea, 281. Patina, 280. Paueispiral operc., 207. Paxillus, *294, Pearls, 30, 433. Pecchiolia, 467. Pecten, 8, 29, 38, #411. Pectunculina, 426. Pectunculus, *425. Pedalion, 418. Pedicularia, *223. Pedipes, *304. Pedum, *414. Pelagella, *332. Pelagia, *354. | Pelli-branchiata, 339. Peloris, 407. Pelta, 290, 323. Pettella, 297. Pen, 173. Pentamerus, *377. Peplidium, 331. Peracle, 352. Periostracum, 33. Periploma, *495. Peristome, 206. Perna, 55, *418. Peronea, 480. Perotis, 170. ‘ Persian Gulf shells, 73. Persicula, 232. Persona, 214. Peru, shells of, 113. Peruvian province, 81. Petaloconchus, *249. Petricola, 476. Pfeifferia, *290. Phanera-pneumona, 305. Phanerophthalmus, *316. Phanerotinus, *267. Pharella, #488, Pharus, 487. Phasianella, *263. Phasianema, 253. Philine, 10, #318. Philippia, 253. Philippine Island snails, 101. . Philomycus, 296. - INDEX. Philonexis, *165. Philebenterata, 339. Pholadidee, *503. Pholadidea, 35, *505. Pholadomya, 454. Pholadomya, *496. Pholadopsis, 506. Pholas, 28, 102, *504. Phorus, *254, Phos, *221. Phosphorar, 23, 295. Photinula, *265. Phragmoceras, *194. Phraemocone, 89, 173. Phylidia, *324. Phyllidiade, *324. Phyllirhoe, *338. Phylirhoide, *338, Phylioda, 480. Phyllodesmium, 335. Physa, 37, *301. Physema, *320, Physiology, 15. Physopsis, *302. Pileolus, #261. Pileopsis, *277. Pilidium, *281. Pinna, 30, 31, #419, Pinnoctopus, *165. Pirena, 36, *248. Pirenella, 243. Pisania, *214. Pisidium, *462. Pisum, 461. Pitonillus, 310. Placenta, *410. Placo-branchus, 839. Placuna, *409, Placunomia, 409. Placunopsis, *410. Plagioptychus, 450, Plagiostoma, 412. Planaxis, #223. Planorbis, *302, Planorbula, 303. Pranulités, 197. Platyceras, 277, Platyodon, 489. Platyschisma, 267. Platystoma, *254. Platystrophia, 380. Plaxiphora, 284. Plectambonites, 381. Plectrophorus, 297. . Pleiodon, 435. Plesioteuthis, *172. Pleure, 21. Pleurobranchea, *323. Pleurobranchide, *322. Pleurobranchidium, 323. Pleurobranchus, *322. Pleurodon, 427. Pleuromya, 497. Pleurophorus, *468. Pleurophyllidia, 325. Pleuropus, 336, 349. Preurorhynchus, 454. Pleurotoma, *228. Pleurotomaria, *270. 515 Plicatula, 55. *414, Plocamophorus, 331. Pneumodermon, 347, #858 Pododesmus, 409. Podopsis, 414, Polia, 487. Polinices, *236. Pollia, 214. Polycera, *330. Polydonta, #304, Polygyra, 289. Polynesian region, 104. Polyphemopsis, 241. Polyphemus, 292. Polytremaria, *270. Pomatias, *307. Pomato-branchia, 312, Pomus, 259. Pontolimaz, 340. Porambonites, *376. Porcellanous shells, 32. Porcellarius, 232. Porcellia, #344. Poromya, 491. Poronia, 459. Portuguese shells, 64. Posidonia, 417. Posidonomya, *417. Posterobranchea, *323. Potamides, *243. Potamomya, *490. Potamophila, 486. Potervoceras, 193. Priamnus, 220, Prisodon, 434. Proctonotus, *337. Productide, *383, Productus, *384. Pronites, 380. Pronoe, 470. Pro-prlidium, 281. Proserpina, 286, *289. Prosobranchiata, *209. Proto, 249. Protocardium, 454. Protozoa, 2. Psammobia, *481. Psammocola, 482. Psammosolen, 488. Psammotea, 480, 482. Psathura, *456. Pseudaxinus, *432. Pseudo-crania, 387. Pseudoliva, *219. Psiloceros, 330, 335. Psyche, *350. Pteroceras, 35, *211. Pteriea, *417. Pterochilus, 336. Pterocyclos, *308. Pterodonta, *315. Pterodoris, 329. Pteronites, 417. Pteroperna, *416, Pteropoda, 346. Pterotheca, *350. Pterotrachea, 342. Pitychina, 456.* Ptychoceras, *201, , “f - 516 Ptychomya, 466. Ptygmatis, *244, Pugiunculus, 350. Pullastra, 475. Pulmonifera, 285, Pulvinites, 418. Puncturella, *273. Pupa, 37, *292, Pupillia, *273. Pupina, *309. Pupinella, 309. Purpura, 23, 36, 56, *222. Purpurina, *222. Pusionella, *218. Pycnodonta, 407. Pygope, 363. Pyramidella, *238. Pyramidellide, *238, Pyramis, 239. Pyramis, *265. Pyramus, 469. Pyrazus, *243. Pyreila, 217. Pyrguila, 246. Pyrula, 24, 32, 37, *217. Pythina, *459, Quenstedtia, *481. Quin, 411. ° Quoyia, 223. Race, 46. Rachis, 21. Radiati, *189. Radiolites, *446. Radius, 234. Radsia, 283. Ranella, 56, *214. Range of marine species, 56. Rangia, 478. Rapana, *217. Raphistoma, *270. Realia, *307. Recluzia, *285. Redonia, *469. Red Sea shells, 73. Leniella, 416. Representative species, 54, 129, Reproduction of lost parts, 40. Requienia, 346, *439. Respiration, 396. Respiratory system, 25, Retractors, 20, 402. Retzia, *374. Reversed shells, 87. Rhabdoceras, *196. Rhegostoma, *309, Rhinoclavus, *242, Rhinodomus, 221. Rhizochilus, 222. Phizorus, 317. Rhodope, *340. Rhodostoma, 304. Ehomboides, 502. Rhyncholites, 182. Rhynchomya, 495. INDEX. Rhynchonella, 55, 358, *370. Rhynchonellide, *375. Lthynchora, 365. Fhynchoteuthis, 182. Ribeiria, *497. Ricinula, *223. Rimella, 211. Rimula, *274. Rimularia, 275. Ringicula, *222, Ringine/la, 314. Risella, *253. Rissoa, *255. Rissoélla, 256. Rissoina, *256. Rivicola, 301. Rossia, #170. Rostellaria, 35, 55, *212. Rotella, *265. Rothomagenses, *198. Rorania, 316. Riudistes, 440. Runcina, *323, Rupellaria, 476. Rupicola, 495. *Sagda, *289. Sagitta, 342. St. Helena shells, 95. Saliva, 36. Salivary glands, 23. Salpa, 19, 23. Sanguinolaria, 55, *482. Sanguinolaria, 481. Sanguinolites, 468, 498. Sardinian snails, 92, Saxicava, 56, *501, Saxidomus, *473. Scacchia, *458. Scea, 352. Sceeureus, *165. Scalaria, *250. Scaldia, *498. Scalites, *270. Scapha, 230. Scaphander, *318, Scaphaniaia, 182. Scapharca, 424, Scaphella, *230. Scaphites, *200, Scaphula, *227, Scaphula, 424. Scarabus, 304, Schizo-chiton, 284. Schizodesma, 477. Schizodus,431. Schizostoma, 267. Schizotreta, 388. Sciadephorus, 165. Scintilla, *460. Scissurella, *269. Sconsia, 225. Scrobicularia, *484. Scurria,.281. Scutus, 275. Scyllea, 8, *333. Sedgwickia, *497, Saymentina, 303. Semele, *483. Semicorbis, 457. Sepia, *177. Sepiadee, *176. * Sepiola, *169. Sepicteuthis, *168, Septa, 184, Septaria, 506. Septifer, 421. Seraphs, *212. Serpularia, 266, Serripes, *454, — Shell, 28, 204. Sigaretus, *236. Szliqua, 488, Siliquaria, #249, Siliquaria, 488. Simpulopsis, 290. * Sinemuria, 470. Sinistral shells, 204, Sinu-pallialia, *472. Sinus, 20. Sinusigera, 212, 352. Siphon, 26, 155. Siphonal impression, 399, 404. Siphonaria, *281, 305. Siphonaria, 387. Siphonida, *436, Siphonopyge, *321. Siphonostoma, 293. Siphonostomata, *289. Siphonotreta, *390. Siphonotus, 320. Siphopatellu, 276. Siphuncle, 39,174,180, 184. Skenea, *256. Smaragdinella, 316. Smell, 18. ~ Solarium, *253. Solecardia, 460. Solecurtotdes, 488. Solecurtus, *488. Solemya, *429. Solen, *486. Solenella, *429, Solenidze, *486. Solenomya, 429. Soletellina, 482. Sormetus, *320, South African province,70. Sowerbya, *478, Spadix, 185. Spanish shells, 64. Spatha, 435. Spawn, 40. Species, 46. Specific areas, 51. Specific centres, 51. Spheera, *457. Spherella, 458. Spherium, 461. Spherulites, 446. Sphenia, *490. Spinigera, *212. Spirigerina, 378. Spiral operculum, 207. Spiratella, 351. Spiraxis, 293, « Spirialis, 347, *351. Spirifera, *371. Spiriferide, *371. Spiriferina, *372. Spirigera, 373. Spiroglyphus, 249. Spirula, 9, *178. Spirulide, *178. Spirulirostra, *177. Spisula, 477. Sponstylotolus, 387. Spondylolites, 183. Spondylus, 7, 30, 35, 38, 55, *413. Spongaria, 180. Spongiobranchea, *354. Sporadic species, 51. Sportella, 457. Stalagmium, 427. Steganostoma, 308. Stenoceras, 197. Stenogyra, *293. Stenopus, *289. Stilifer, 9, *241. Stoastoma, *310. Stomatella, *267. Stomatia, *268. Stomatia, 236. Straparollus, 267. Strephona, 227. Strepsidura, 218. Streptaxis, #289. Streptorhynchus, 380. Striati, *189. Strigilla, 480. Strobilus, 294. Strombide, *210. Strombus, 31, *210. Strophalosia, *885. Stropheodonta, 381. Strophomena, *380. Strophostoma, 308. Structure of shell, Brachi- opoda, 360. Struthiolaria, *246. Stylina, 241. Styliola, 349. Stylocheilus, *321. Stylopsis, *239. Styloptygma, *241, Sub-clymenia, 190. Sub-generic area, 52. Sub-spiral operc., 208, Subula, 220. Subulina, 292, - Succinea, *290. Suessia, *372. Sulco-buccinum, 219. unetta, 474. usaria, *323. Suture, 180, 206. Sycotypus, 217. Syncera, *256. Syndosmya, *483. Synonyms, 48, Syrnola, 238. Tagelus, 488. _ Tanalia, 247. : INDEX. Tancredia, *457. Tanysiphon, *477. Tanystoma, *290. Taonius, 170. Tapes, #475. Taste, 18. Tebennophorus, 296. Tectaria, *252. Tecti-branchiata, *312. Tectura, 281. Tequila, 264. Teinotis, *269, Tetlina, 458. Tellina, *480. Tellinide, *479. Tellinides, *480. Tellinodora, 480. Tellinomya, *497. Temnocheilus, 189. Temperature, 39. Tentaculites, *190. Tentaculites, 350. Terebelum, *212. Terebellum, 248. Terebra, 55, *220. Terebralia, *243. Terebratella, *365. Terebratula, 19, 38, 357, 358, *363. Terebratulidee, *363. Terebratulina, *364. Terebrirostra, 365. Teredina, *507. Teredo, 35, 341, *506. Tergipes, *335. Tertiary shells, 130, Testacella, 9, *298. Tethys, *333. Tetrabranchiata, *178. #etraplodon, 434. Teudopsis, *168. Teuthidee, *167. Teuthis, 167. Texture of shells, 29. Thalassides, 470. Thallicera, 259. Theca, 190, 346, *349. Thecacera, *330. Theceurybia, 350. Thecidium, 358, *369. Thecosomata, *348. Thetis, *491. Thiara, 246. Thoracoceras, *191. Thoracoceras, *195. Thracia, *495. Thyuatira, 456. Thysanoteuthis, #172. Tiara, 231. Tichogonia, *423. Tiedemannia, *351. Tomella, *229. Tomigerus, 289. Tongue, 287. Tonicia, 283. Torcula, 248. Torinia, *253. Tornatella, *313. Tornatellidz, *312. 517 Tornatellina, *294, Tornatina, *315. Torquilla, 292. Toxoceras, *200. Trans- Atlantic prov., 85. Trapezium, 467. Trawling, 139. Tredopsis, *289, Trematis, #389. Tremoctopus, 159, ¥164. Trevelyana, *331. Triboniophorus, *297. Trichites, 31, #420. Trichocyclus, *354. Trichotropis, 33, 55, *216. Tricolea, 263. Tridacna, 13, 35, 55, *452. Tridacnide, #451. Tridonta, 464. Triforis, 37, *242@ Trigona, *474. Trigonella, 375, 477, 484. Trigonellites, 182. Trigonia, *430. Trigoniadz, *430. Trigonoceras, 194. Trigonocelia, 426. Trigonosemus, *365. Trigonotreta, 371. Trigonulina, 472. Triomphalia,506. Triopa, *330. Tritoceras, *192. Triton, 33, 36, 55, 56, *214 Tritonia, *332. Tritoniade, *332, Trivia, *233. Trochalia, *244. Trochatella, 276. Trochatella, *310. Trochiscus, 264. Trochita, #276. Trochoceras, *189. Trocholites, 189. Trochotoma, *271. Trochus, 23, 38, #264. Tropeum, 199. Trophon, 55, *218. Tropidophora, 307. Truncatella, 36, #256. Tuba, 256. Tubular structure, 32. Tudora, 307. Tugonia, 489. Tunicata, 5. Turbinella, *216, Turbinellus, 31. Turbinide, *263, Turbo, 23, *263. Turbonilla, 239. Turcica, 265. Turrilites, *200. Turris, 228, 231. Turritella, 36, *248, Turritellide, *248, Turtonia, *459. ‘* Tyleria, *496. Tylodina, *324. . Tylostoma, *314, 518 Tympanotomus, 243. Types, 49. Typhis, 27, *213. Umbo, 29, *398. Umbonal area, 404. Uncini, 21. Uncites, *374. E Unguiculate operc., 207. Ongula, 392. Ungulina, *458. Umbilicated shells, 205. Umbrella, *323. Unicardium, *457. Unio, 29, 30, 33, 109, *433. Unio, 497. Unio, distribution, 87. Unionide, *432. Onionites, 468. United States shells, 85. Ctricuius, 317. Vaganella, *479, Vagina, 487. Vaginella, *349, Vaginulus, *300. Valvata, *260. Vanicoro, 237. Varices, 13. INDEX. Varieties, 46. Varigera, *314. Warix.top, Velates, #261. ~ Velletia, 286, *302. Velorita, *463. Velutina, 55, *237. Venericardia, *472, Veneride, *472. Venerupis, *476. Venilia, 337. Venus, 56, *473. Verania, 171. Vermetus, 7, 36, *249. Veronicella, *300, Vertebrata, 1. Verticordia, *472. Vertigo, *293. Vibex, *247. Villiersia, 329. Viquesnelia, #298, Vitrina, *290. Vitrinella, *265. Viviparous reproduction, 0 Viviparus, 257. Vola, 412. Volupia, *473. Voluta, 32, 55, *230. Volutella, 230. Volutidee, *229. Volutilithes, *230, Volva, 234. Volvaria, *232. Volvula, *315. Vulsella, 55, *416, Waldheimia, 19, 357, *364. Waltonia, *368. West African province, 69. West American shells, 77. West Indian shells, 84. Woodwardia, 269. Aanthonella, 316. Xenophorus, 254. Xiphoteuthis, *175. Xylophaga, *506. Xylotrya, *507. Yetus, 231. Yoldia, 55, *428, Zaria, 248. Zellania, *368. Zephrina, 337. Zierlania, 231. Zirfeea, 505. Zonttes, 289. Zua, *292, Para INDEX TO FIGURES. Achatina, 286. ~ Actinoceras, 191. girus, 327. Ammonite, 179, 181, 197, 199. Ampullaria, 258, 259. Ancula, 327. Anodon, 398. Anomia, 402. Aporrhais, 245. Argiope, 368, 369. Argonauta, 161, 162. Ascidia, 6. Astarte, 465. Athyris, 373. Atrypa, 378. Aulosteges, 385. Auricula, 303, 304. Bela, 228. Belemnoteuthis, 176. Biradiolites, 438. Bouchardia, 366. Buccinum, 22, 219. Bulimus, 44, 291. Bulla, 22. Calceola, 383. Camarophoria, 377. Caprinella, 449, 450. Caprotina, 451. Cardium, 454. Carinaria, 202, 343. Cassis, 224. Ceratites, 197. Cerithidea, 209, 243. Chama, 437. Chilinia, 301. Chitonellus, 284, Chonetes, 386. Clymenia, 180, 190, Conocardium, 455. Conularia, 350. Conus, 32, 34. Crania, 387, 388. Crassatella, 466. Crenella, 43. Crepidula, 275. Cyclophorus, 306. Cyclostoma, 307. Cymba, 29, 231. Cyprzea, 21, 35, 233. Cypricardia, 468. Cytherea, 20. Dendronotus, 327. _ Diceras, 439, 440. Diplodonta, 456. Discina, 388, 389. . Dolium, 225, 226. Doris, 41. Dredge, 141. Dreissena, 19, 423. Endoceras, 193. Eolis, 17, 203. Fasciolaria, 215. Fissurella, 273. Glycimeris, 494. Gomphoceras, 181. Goniatites, 181, 193, 196. Grypheea, 35, 408. Gyroceras, 194, Hamites, 180, 201. Helix, 4. Hippurites, 444, 445, 446. Huronia, 192. Hyalea, 4, 348. Tanthina, 6, 271. Tsocardia, 467. Kingena, 368. Kraussia, 367. Leptena, 381. Lepton, 18, 460. Limax, 295. : Lingula, 391. Littorina, 207, 250, 251. Loligo, 4. Lymnea, 301. Maclurea, 345. Magas, 366, Merista, 374. Modiola, 403, Monopleura, 438. Morrisia, 366. Mulleria, 436. Murex, 213. Mya, 6, 396, 489. Mytilus, 43. Natica, 235. Nautilus, 180; 186, 188. Navicella, 262. Nerita, 207, 260, 261. Obolus, 392. Octopus, 164. Ormoceras, 191. Orthis, 379. Orthisina, 380. * Ostreea, 442. ‘Paludina, 203. Panopea, 493. Patella, 279. Pearl, 31. Pecten, 17, 401, 411. Pentamerus, 377. Philine, 312,319. Pholas, 505. Phorus, 254. Phragmoceras, 181, Pinna, 31, 415. Pirena, 248. Pisidium, 460. Planorbis, 303. Productus, 382, 384. Psammobia, 26, 482, Radiolites, 442, 446, 447, 448, Requienia, 439, 440. Retzia, 374. Rhynchonella, 5, 374, 376. Risella, 252. Scissurella, 269. Sepia, 160, 166. Siphonaria, 305. Siphonotreta, 390. Solarium, 253. Solen, 487. Spirifera, 372. Stringocephalus, 370, 371. Strombus, 210, 211. . Strophalosia, 385. Strophomena, 381. Struthiolaria, 246. Terebratella, 365. Terebratula, 5, 31, 355,361, 363. Terebratulina, 364. Teredo, 507. Testacella, 298. Thecidium, 369, 370. Thetis, 491. Tornatella, 313. Trawl net, 139. Trichotropis, 217. Tridacna, 452. Trigonellites, 182. Trigonia, 25, 430. Triton, 205, 215. Trivia, 233. Trochus, 21, 38, 207, 264, Uncites, 374. Unio, 399. Velutina, 237. Voluta, 230. Waldheimia, 364. Yoldia, 428, 429. EXPLANATION OF THE PLATES. Tue principal specimens figured were kindly communicated by Mrs. J. E. Gray, Mr. Hugh Cuming, Major W. E. Baker, Mr. Laidlay of Cal- cutta, Mr. Pickering, Sir Charles Lyell, Mr. Sylvanus Hanley, Prof. James J'ennant, and Mr. Lovell Reeve. The fractions show the number of times (or diameters) the figures are reduced, or magnified. PLATE I. Octopodide. Page 1. Octopus tuberculatus, Bl. 4. Mediterranean ..........3++. 160 2. (anamdibles) ..ccveceesaees Thar OS i>. Pie. 156 3. Tremoctopus violaceus, ¢. Chiaje. Messina .......... 159, 164. Teuthide. 4, Sepiola Atlantica; Orb. Atdantic.....i.seseesveeen shee ola. st 169 6. Loligo vulgaris, Lam. (gladius). 1. Britain...........+. eae 7. Onychoteuthis Bartlingii, Le Sueur. 4. Indian Ocean..,... bees 8. (gladius). 4. esd u aap e'e.c'0 0 py wise ean tSIn ae een Seprade. 6. Sepia officinalis, L. ,2. Britain ........k...)70. 177 Spirulide. 9. Spirula levis, Gray. 4. New Zealand ..........0 5s ahaa »~ 178 ys Ne SSSR oOo es FSA\™% } J.P. Woodward. SW. Lowry = a B ot a s E ‘Ss =u ia LL SP. Woodward. renee = a em: fy Wi Lowry Je. of ON EXPLANATION OF THE PLATES. | 521 PEATE (I. Argonautide. ; Page paesonauia hians, Solander. 3. - Chima - ......cecaensceeve 162 Teuthide. . Beloteuthis subcostata, Miinst. +3. Upper Lias, Wurtemberg 168 - Belemnitide. » Belemnites Puzosianus, Orb. 1. Oxford Clay, Chippenham 173 . Belemnitella mucronata, Sby. 1. Upper Chalk, Norwich .. 175 . Conoteuthis -Dupiniana, Orb. Neocomian, France; Gault, eee aes x at oc ah dew eam ee So te eee 176 Sepiade. 2. Sepia Orbignyana, Fér. 4. Mediterranean .............. By i 3. —— (Belosepia) sepicidea, Bl. 4. Eocene, Sussex ........ 177 4, Spirulirostra Bellardii, Orb. +. Miocene, Turin ....... erry 7. Beloptera belemnitoides, Bl. 2. Eocene, Sussex.......... 177 ; Nautilide. * 10. Nautilus radiatus, Sby. 4. Neocomian, Kent ............ 185° 11. bidorsatus, Schl. («upper mandible = Rhynhcolites hirundo, F. Biguct). %. Muschelkalk, Bavaria 183 12. --—{ Aturia) zic-zac, Sby. Eocene, Highgate ........ 189 16. Clymenia striata, Miinst. Devonian, 8. Petherwin ........ 190 Orthoceratide. “14, Orthoceras Ludense, Sby. (section). 1. Ludlow Rock, Britain 190 15. Phragmoceras ventricosum, Stein. =. L. Ludlow-rock, Salop 194 13. Gyroceras eifeliense, Arch. (section). 3. Devonian, Eifel ., 194 ko MANUAL OF THE MOLLUSCA. ~ PLATE IIT. Aimmonitide. Page . Goniatites Henslowi, Sby. 3. Carb. limestone, Isle of Man 196 1 2. Ceratites nodosus, Brug.. 4. Muschelkalk, Wiirtemberg ie 3. Ammonites planulatus, Sby. 34. . Chalk-marl, Sussex ...... 199 4, rothomagensis, Brongn. 3. Chalk-marl, Sussex 198 5. —————— spinosus, Sby. 4. Oxford Clay, Chippenham.. 198 6. ——— bifrons, Brug. {. Lias, Whitby... J. ..eemeum 198 7o-—— bisuleatus, Brug. 3. Lias, Lyme Regis........ 198 8. Crioceras cristatum, Orb. 4%. Gault, S. France............ 199 9. Scaphites equalis, Sby. » 3. Challk-marl, Sussex .......... 200 10. Ancyloceras spinigerum, Sby. 2. Gault, Folkestone ..,... 200 11. Helicoceras rotundum, Sby. Gault, Folkestone............ 200 12. Toxoceras annulare, Orb. +. Neocomian, 8. France ...... 200 13. Baculites anceps, Lam.” 4. ‘Chalk, France. .:....9sguy eee 201 14. Ptychoceras Emericianum, Orb. 3. Neocomian, 8. France 201 15. Hamites attenuatus, Sby. +. Gault, Folkestone .......... 20h} 16. Turrilites costatus, Lam. +4. Chalk-marl, Sussex mre 200: S.P Woedward. ‘nat rg we ih, | Hervey ‘mui | JT.Wiowry Je- ee | mt Fi.q. JW. Lowry SP Woodward. EXPLANATION OF THE PLATES. 523 PLATE IV. Strombide. Page mec aromas pops i. 2. '“W. Indios =... ees cw eqeeee 210 2. ——- Bartonensis, Sby. Hocene, Hants ...........0-. 211 eeeerer rmmetarriis, £1... a. Obirta * oo. 0S. icon. we seve s oe ee 222 . Monoceros imbricatum, Lam. 3. Cape Horn ............ 223 iceman wie protia: Siw. Sicily." ost cats ese Fs Se eee woe 223 | ieermealcaia. brug. sp. India. i. .cci es. ce. ee ten ane ee 223 j 5 (OPISTOCMLAUA) | odia'e sie le's « «.ae,s 0 e's 5\4 sow ee baleen 224 =) eeuewouropis borealis, Brod. N. Britain ........ctsecaues 216 inemniaaraeinoides, Lam, China. s06. 6... .ctneue sete 223 . Columbella mercatoria, Gimel- sp. “W. “Hnidies..i...70-eaneen 226 peifera yeniricosa, Lam: +. ° Mauritius ........cssetecacd 226 . Dohum galea, L.sp. 3%. Mediterranean 2.1.2... sccenees 225 | cassidaria echinophora, I. 2. > Medit.. 0.00... abs foe onto 225 Remit ed, Pak CUDA wee os oc bass tee o's ee ne 0d oe ae se Soe P Crmuncs cancellatas Shy. Chips i... se ermces vase eee 225 Pilave porphyria, le 2, Panama sf... one dese. tees aea te 226 — (Agaronia) hiatula, Gm. sp. 3. W. Africa .......... 227 (Scaphula) utriculus,Gm.sp. 2%. Africa .........06. 227 — (Olivella) jaspidea, Gm. sp. W. Indies ............00- 227 . Ancillaria subulata, Lam. %. Eocene, Isle of Wight ...... 227 — glabrata, L. sp. 34. -West Indies ............:. 227 OMT AO Fe CH te 94, 25, 5 MANUAL OF THE MOLLUSCA. PLATE VII. Conidae. 2 *Coenns marmoreus, Gm. 2)°Chima \)3... .. ve eee . Volutilithes spinosus, L. sp. 2. Eocene, Barton .......0.. . Melo diadema, Lam. sp. 4. New Guinea....... eT ‘ws . Cymba proboscidalis, Lam. sp. +. W. Africa ,.......ce0s . Mitra episcopalis, D’Arg.. 5. Ceylon 2... 7.5 wee oe «(6 ene a . ~— vulpecula, L. 4. Singapore ........... +s kag . — (Imbricaria) conica, Schum.~ Tahiti. ........ ‘s+ ganas . — (Cylindra) crenulata, Chemn., China ......seseeerees . Volvaria bulloides, Lam. Eocene, Grignon ...... + aaa . Marginella nubeculata, Lam. 4. W. Africa... 2 Kile a 6 ath ae —— (Persicula) lineata, Lam. W. Africa.......... Is Cypreide. . Cypreea Mauritiana, L. 3. India—Pacific...........+. os Hd. (Cyprovula) capensis. Gray. 3. S. Africa........ : (Luponia) algoénsis, Gray. S. Africa .......eeseeee 23% Erato levis, Donovan. Britain ........ os os 000K bee Ovulum ovum, L. sp. 3. New Guinea .sseseseceeeeereee (Trivia) europea, Mont. Britain .....60...+0--+ SP Woodward. = r s > { ‘ ‘ ‘ < ‘ ' “ ial at ay ba . 4. | p f * rs rs =| A a i “ v \ ‘ x ; | . : , é ’ ky 3 s ot af A oy > ees + % te 2 i a oe SP. Woedward. TW LOU. hfe. EXPLANATION OF THE PLATES. PLATE VIII. Nuaticide. Page Pearemcanrena, 1 spi . 3.) CDA view ence cvanscaaeectues eae 2. (Globulus) sigaretina, Lam. 3. Eocene, Paris ...... 236 3. — (Cernina) fluctuata, Sby. 3. Philippines .......... 236 4. Sigaretus haliotoides, L. sp. 3. W. Indies .............. 236 5. — (Naticina) papilla, Chemn. sp. Africa............ 236 6. Lamellaria perspicua, Mont. Mediterranean ............4. 37 Pea clurininslovseata, Er sp. “ Dritatii 5.00 ss de saccs sow e gem 237 8: WNarica cancoellata, Chemn. sp. | Pacific ........00scsseeceee 237 9. Neritopsis radula, L. sp. Sandwich Islands .............. 261 _ Pyramidellide. 10. Pyramidella auris-cati, Chem. sp. Mauritius ..........006. 238 11. ——_——-— (Obeliseus) dolabrata, Gmel. sp. W. Indies .... 238 12, Odostomia plicata, Mont. sp. 2. Britain ........ssseees . 239 13. Chemnitzia elegantissima, Mont. sp. 2. Weymouth ...... 239 14, Hulima-polita, L. - Britain. ..........008 Pea Bee oA He 240 iiepiiliter agricola, Brod. “Philippines. .. cxie.e.ecwsmicmonieine os 241 ; Cerithiade. 16, 16*. Cerithium nodulosum, Brug. $. Moluccas .......... 242 Av. (Bittiwm) reticulatum, Da Costa. Britain.... 242 18. Triforis perversum, L. sp. Mediterranean ..........00-205 242 19. Potamides mixtus, Defr. Eocene, Paris ............seeees 243 20. (Pyrazus) palustris, Brug. }. India ............ 243 21. (Zerebralia) telescopium, Brug. 3. India........ 243 22. -. (Pirenella) mammillatus, Risso. sp. Mediterranean 2438 23 (Lampania) zonalis, Lam. Chusan ........00e08. 244 24 (Cerithidea) decollatus, L. sp. Cape.......-..e06- 243 Melaniade. 25, 25*. Melania amarula, L. sp. %. Madagascar ............ 246 26, (Melanatria) fluminea, Gm. sp. 3. Madagascar 247 27 — (Welafusus) fluviatilis, Say. 3. U. States .... 247 28. —— (Aneulotus) preemorsa, Say. U. States 29. (Vibex) fuscata, Gm. sp. Africa .. aN vee 30. Melanopsis costata, Fér. Syria.........e0- wf Ss Gaerne als (Pirena) atra. L. sp. 3. Ceylon othe ee Oe (8 MANUAL OF THE MCLLUSCA. \F PLATE IX. Turritellide. Page 1. Turritella imbricata, L. “W. Indies ..:.3. 3... dss pe aeeee eee 2. (Mesalia) sulcata, 1 var. Lam. \ Mocene, Paris’ 3. sae 249 3 (Proto) cathedralis, Brongn. {. Miocene, Bordeaux 249 4, Aclis supranitida, Wood. 2. Guernsey Re oe re el] 5. Caecum trachea, Mont. 4, Britain ...... cheecene cee aalee 249 6. (fry, egal Be) eee aebcn weep eeeeeeesbens rar 249 7. Vermetus lumbricalis, Gm. sp. (young). W. Africa ..... woe 249 8. Siliquaria anguina, L. sp. 4.. New Guinea «sn. c.05 = see 249 9. calaria pretiosa, Lam. 2. China .......<0:¢«s0 nee 250 Littorinide. Pyetinoriia littorea, ts." Britain... sca Sse seals ry Sh) il. — — (Lectaria) pagodus, L. 4. Yanzibar ... ae pomoanpullaria globosa, Sw...4. - India \.6.\s..)- 2s eaeeemee .. 208 31. —————— (Marisa) cornu-arietis, L. sp. Brazil ....... wav 209 32. —— (Lanistes) Bolteniana, Chemn. sp. 3, Nile .... 209 30, Amphibola australis. New Zealandss....... cssede vseueuues 259 34. Paludomus aculeatus, Gm. sp. Ceylon........ See ee 247 Neritida. SD. verita mstrlata, As. SCI 0.0.06) 0 5.00 0.0 3 so kg skeen 36. (Velates) perversus, Gm. sp. ‘Eocene, Sossons .... 2. 261 37, 88. Pileolus plicatus, J. Sby. Bath Oolite, Ancliff........ 261 39. Neritina zebra, Brug. Pacific ...... Patience cite as eee eee 40. crepidularia, Less. India ....... ode 0 b.« it Ree 41. Navicella porcellana, Chemn. sp. Mauritius—Pacific ...... 262 = SP Woodward . whe WLowrs Tes | | EFF 4 TWLowry | fe. i SL. Woodward EXPLANATION OF THE PLATES. 529 PLATE. X. Page 1. Phorus corrugatus, Reeve. 4. Kurachee, India ......... . 264 Turbinide. Pemerrvomarnoratus, Lb. +.- China... . 5.0 Risienseclaes- 263 3. Phasianella australis, Gm. sp. 2% New Zealand .......... 263 4, Imperator imperialis, Chemn. sp. 3. New Zealand........ 264 #82 eerochus niloticus, Ll. 2.) China .t...6.. 2.0.05: -. eae Soe 264 6. (Pyramis) obeliscus, Gm. sp. China ....../....... 265 7. —— (Margarita) helicinus, O. Fabr. Britain .......... 265 §. ——— (Llenehus) iris, Chemn. New Zealand ............ 265 9. (Bankivia) varians, Gray. New Zealand .......... 265 10. Rotella vestiaria, L. sp. New Zealand ........cceeecee eeee 265 Mamonddenta lapio, Ty. sp.i'W. Africas... ....78s0) Ree 265 12. (Clanculus) Pharaonis, L. sp. Red Sea ........ 265 fools Jacinata, Lam. \(Whina °.... 2... os sds scce s Sere 266 14. ————— (Liotta) Gervillii, Defr. Eocene, Sussex ...... 266 15. —————— (0Odllonia) marginata, Lam. 14. Kocene, Paris 266 16. —— (Cyclostrema) cancellata, Marryatt. Philippines.. 266 17. Adeorbis sub-carinatus, Mont. sp, Britain ................ 26€ 18. Euomphalus pentangulatus, Sby. 3. Carb. limestone, Ireland 267 19. Stomatella imbricata, Lam. India ............. Brey 267 20. (Brodertpia) rosca, Brod. 2. 8. Seas eve CORE 267 Haliotide. 21. Haliotis tuberculata, L. Guernsey ........ eet ors 268 22. Stomatia phymotis, Helblin. Java ..........ce0es ne aa 268 23. Scissurella crispata, Fleming. #. Britain ................ 269 24. Pleurotomaria Anglica, Sby. 34. Lias, Gloucester ........ 270 25. Murchisonia bilineata, D’Arch. Devonian, Eifel .......... 270 . Trochotoma conuloides, Desl. Bath oolite, Stroud........ wes 271 . Ianthina fragilis, Lam. %. W, Indies ..........sececees 271 530 MANUAL OF THE MOLLUSCA. PLATE XI. Fissurellideé. ‘ Page dS Hissorevia duster, ‘Orb. W. Indies oh.\s soy). sas peter cane saree ees ‘ macrochisma, Humphr. Philippines............ 273 - so Ponctirella Noachina, L: sp. N. Britain. « 7.°.0/ ae eee 273 4, Rimula-Blainvillii, Defr. Philippines ............... ere 5, 6. Emarginula recticulata, Sby. Britain........ scars oes 274 ios: (Hemitoma) rugosa, Quoy. Tasmania........ 274 9. Parmophorus australis, Bl. 3. New Zealand ..... ...... 274 Calyptreide. 10. Calyptreoa equestris, L. sp. Philippines ............s000.- 276 11. — Dillwynnii, Gray... Wi Indies. ooo... neneeenee 276 12. — (Crucibulum) rudis, Brod. W. America.......... 276 "3, 14. —— (Trochita) radians, Lam. W. America .......... 276 . 16,.15*. Bincaaws, L..” Britain .:'..° Ags. sa eee 276 16. Crepidula fornicata, L. sp. W. Indies.......... io 277 2 Pileopsis: Hungaricus; L. 2. ‘Torbay -.\.. 0... >. ae 277 18. — moilitaris,.. -W. Indies $v... nese oe r+ ie 19. ——— (Amathina) tricarinata, Gray. 3% India.......... O77 20. Hipponyx cornucepie, Defr. 4. Eocene, Paris .......... 278 Di (Shelly bas0) sii ches os ee coe o's so bhaineann 278 Patellide. : 29. Patella longicosta,duam. 2- Cape... ...0ackiseds cee 279 23, —— (Nacella)@pellgigida, L. Britain. ...s3.......9s000us 280 24, Acmea testudinalis, Mill. sp. Britain............-- toe 25. Siphonaria sipho. Kurachee, India... .....cnseuees aps oe: aia ‘pernviand, Gray. ~ Per: 13. o)40. .05 05 sae eee 281 Dentaliade. 27. Dentalium elephantinum, L. 4. RedSea.........sseeeee 282 Chitonide. . 28. @urtor squamoras; L. "%. “W. Indies ..‘:, ..2,~: aeneuae »- 282 29. — (Acanthopleura) spinosus, Brug. N. Australia ...... 283 30. ——— (Acanthochites) fascicularis, L. Britain .......... +. 284 31 : (Chitonellus) fasciatus, Quoy. -}. Philippines AUP TT SP Woodward. oh Whowry fe. 4 EXPLANATION OF THE PLATES. yn | .» PLATE X11. Helicide. é Page 1. Helix (Acavus) hemastoma,sL. 2. Ceylon .icccscccceeee 289 2. (Polygyra) polygyrata, Born. }. Brazil ............ 289 3. —— (Carocolla) lapicida, L. Britain ...... au.0 damige tances 289 4. ——/ (Anasioma) globulosa, Lam. Brazil ............0003 289 5. —— *(Tridopsis) hirsuta, Sby. U. States ...... ....00 cece 289 6. —— (Streptaris) contusa, Fér. Brazil ......ccceceeeceeee 289 7. —— (Sagda) epistylium, Mill. Jamaica ................ 289 8. —— (Helicella) cellaria, Mill. Britain ..... a oe iia ee ear 289 9. (Stenopus) leevipes, Mill. Malabar................:- 290 10. Bulimus oblongus, Mill. 4. Guiana...,.. aGhialoce Sal g toile 291 oi re. decollatus, L. S. Europe......... cast alee Oe Sait eae 291 13. (Partula) faba, Martm. ‘Taliti 32.0.5 6600.00! whe eee 14, (7). lubricus, Mulls) Briain | sie aisie cas aaeage 292 15, (Azeca) tridens, Pulteney. Britain: .....6....000 292 PO Pepe tua tna. Antiadaloupe’s. (00 c.. os. ese occ eatin 292 17 (Vertigo) Venetzii, Charp. %. Pliocene, Essex ...... 293 18. Megaspira elatior, Spix sp. $ Brazil .......0..eecvesees \ 294 19. Clausilia plicatula, Drap.Wlheners Ls... waveltes cee ew eed ame 294 20. Cylindrella cylindrus, Chem. sp. 3. Jamaica ............ 293 21. Balza perversa, 1 SDT las 5 i. 1218 ae Rao Phen \* va. ee 22. Achatina variegata, Fab. Col. 3. W. ee jae la 292 fameinen mniris, Ts. Britain -. .. ..0. 14“. onus aca ees 290 24 (Omalonyx) unguis, Orb. Paraguay ........ aig mee 291 Limacide. 25. smax maximus, L. Britain.......... 85 LE. ps heed hee 295 26. Testacella haliotoides, Fér. 2 Britain ......... ss ea 298 27. Parmacella (Cryptella) calyculata, Sby. Canaries .......... 297 Bae Vere eraparnaidi.. Cuy,-Brigin 2. see. eee ee cues 290 29 (Daudebardia) brevipes, Drap. 2. Austria ........ 290 Limneide. 30. Limnea stagnalis, L. sp. Britain.............. eee dae ee 31. (Amphipeplea) glutinosa, Mill. Britain............ 301 32. Physa fontinalis, Mont. sp. Britain .............6- sah ahr ee . Ancylus fluviatilis, Misterep. Beraan:. . . 0s. ce etme 302 34. Planorbis corneus, L. sp. Britain ......... « beatae 302 Auricilide. oo, mertcma duds, Ti. 2. India. seicccscdescssceace ineteeee 304 36. scarabzeus, Gym. sp. Ceylom..........ssceceeeee 304 37, Conovulus) coffea, L. W. Indies ......ee..eeeeee 304 38. ea denticulata, Mont. sp. Britain ........ .. 3805 39. Carychium minimum, Drap. sp. 3. Britain... 2 305 Cyclostomide. 40. Cyclostoma elegans, Miill. sp. Britain.. dapneie Ga) alae 306 41. Cyclophorus involvulus, Mull. sp. 4. Tits. ....-- ee 308 42, Pupina bi-caniliculata, Sby. Wy Pieptralia®. .. ncn. one's one 309 48. Helicina Brownii, Gray. Le Sn en eee b! 44, Acicula fusca, Walker, sp. 4. Britain ...... “Qe apa 0. 532 MANUAL OF THE MOLLUSCA. PLATE XII. The real size of each species is indicated by the accompanying line. cs CY 1 coo t Doridide. Page . Doris Johnstoni, A. and H. ‘Brit. (low water) .........-s. 328 .dxoniodoris nodosa, Mont. sp. Brit. ..... 1.00509 eee 300 wal iopa claviger, Mull.‘sp. - Brit.cs. 625.6. + ous 330 » 4upirus-punctilucens, D’Orb.’: Brit. 2. 60/0155. (ae eee 330 . Polycera quadrilineata, Mull. sp. Europe. (Laminarian zone) 3380 . Idalia'aspersa, A. and H. Northumberland................ 331 Tritoniade. . Tritonia plebeia, Johnst. Brit. (Coralline zone) .......... 332 . Scyllea pelagica, L. Devon (pelagic). ..........ssee seen we 333 > Lethys firhbriata, La: Medit. (pelagic) .......... sche ws eee . Dendronotus arborescens, Mull. sp. Brit. .......20:0.5 000s 304 '=Doto,coronata, Gam. sp... Brite ccssisiis 6.0 0 s'e 4 Slee genet ae 334 . Lomanotus marmoratus, A.and H. Devonshire coast..... . dot Holidide. . Aolis coronata, Forbes. Brit. (Laminarian zone) ........ 335 . Glaucus Atlanticus, Bl. Gulf-weed banks .......eseeeeers 336 . Embletonia pulchra, A.and H. N. Brit...... 2 Sea Waele 336 . Proctonotus mucroniferus, A.and H. Dublin Bay ........ 337 . Hermea bifida, Mont. Brit. Lit—lLaminarian zone ...... 338 . Alderia modesta, Loven. Brit. Salt-marshes ..........0. 338 Elysiade. . Elysia viridis, Mont. sp. Brit. ....... OY OO wemgee 339 . Acteonia corrugata (head), A. and H. Falmouth .......... 389 - » Cenia Cocksii, A. ahd H. Falmouth.........., oo 339 . Limapontia nigra, Johnst. Brit. ......... ioe ioe Kesinue p ORO n SP Woodward We WLewrv fe. Sits ivdwae . JWla NTV fe. EXPLANATION. OF THE PLATES. 533 PLATE XIV. Opistho-branchiata. Page 1. Tornatella tornatilis, L. Brit. ...... ee ee ee ee . 313 2. Cylindrites acutus, Sby. Bath Oolite, Brit....... en 3. Acteonella Renauxiana, D’Orb. 4. L. Chalk, France AEE 314 4, Cinulia avellana, Brongn. U. Greensand, Betis eee 314 5. Tornatina voluta, Quoy sp. 3. I. Guam, Australia...s...3 olf 6. Bolla ampulla, tn. 4. India ......50..00. Paes cecccenea SLO f (Atys) naucum, L 4. Philippines....... a a epenen ig 316 8. Linteria viridis, Rang. Pitcairn Id. ........ eeenviaed ae ae 316 Oo Acer Dullata, Mall. Brit. ......6. 008. SS err e 316 10. Cylichna cylindracea, Mont. Brit. .......e2008 odahes 317 11. Aplustrum aplustre, L.sp. 4. Mauritius ........cceecees 318 12. Scaphander lignarius, L. sp 2. Britis cccceers ao dine 318 13. Philine aperta, L. sp. Brit. we wy ioe cae bins eee 14. Aplysia depilans (hybrida, Sby. ye ee 320 15. Dolabella scapula, Martyn, sp. 4. Mauritius .........-.. 321 1G. *Eobiger Philtppii, Krohn. Sicily o...i. cecevslscncceuchaat 322 17. Pleurobranchus membranaceus, Mont. 2. Brit. .......... 322 18. Umbrella umbellata, Dillw. +. Mauritius............000: 323 Nucleobranchiata. 19, Carinaria cymbium, L. 4. Medit. ........ binely iA cn cae 343 20. Cardiapoda placenta, B.and 8. =, Atlanti@..... 0.5 .senae 343 21. Atlanta Peronii, Les. 22, operc. 23, fry. S. Atlantic ........ 344 24. Oxygyrus Keraudrenii, Rang. 25, operc. §. Atlantic .....: 344 26. Bellerophina minuta, Sby. Gault, BRGY Se 0 Aes ete ee 345 27. Bellerophon bi-carinatus, Lévy. 4. Carb. Limestone, Torunay 344 28. ——————- expansus, Sby. 4. U. Silurian, Brit. ..... ... 345 29. Porcellia Puzosi, Lév. 4. Carb. Limestone, Belevam i. onc 344 30. Cyrtolites ornatus, Conrad (cast) 2. L. Silurian, U. States 345 31, Ecculiomphalus Bucklandi, Portl. 3. Silurian, Tyrone ..s 348 Pteropoda. 32. Hyalea tridentata, Gmel. Atlantic—Medit. ....cccceeceee 348 aa» Gleodora pyramidata, L. Aflantio,....50.0000curevsace een 349 a4. Geoseis aciculata, Kane Atlantic ..... ..sacvacceavcdveess . 349 35. Cuvieria columnella, Rang. S. Atlantic ........ rate hay Oe ae 36. Vaginella depressa, Basterot. 3. Miocene, Bordeaux ...... 349 37. Eurybia Gaudichaudi, Souleyet SS. Pacific (Huxley) . 350 38. Psyche globulosa, Rang. Newfonhdlandic.. ys «cidddincsemaies 3d1 39. Cy mbulia pr oboscidea, Pesons:| Medific «cd, saadunucrsducoe 3d1 40. Tiedemannia Neapolitana, Chiaie. © Madit.c-24 ws: cea cena 351 41. Limacina antarctica (J. Hooker). S. Polar Seas, 63°—46° .. 351 42. Spirialis bulimoides, D’Orb. sp. Atlantic............e0ce-- 351 43. Cheletropis Huxleyi, Forbes. 5. 8. E. Australia........ 352 44. Macgillivraia pelaciga, Forbes. 2. C. Byron, E. Azistealaea 352 45, Cho borealis, Brug. Arctic Sead. ....secccesscees Cuenmeue 53 46, Spongio- branchea australis, D’Orb. 3. §S. Atlantic, Falk- . EE Fe U ass xu Kei to Ue dp A) ah 2e SERV eRe. ae ee 354 47. Pneumodermon violaceum, D’Orb. 3. §. Atlantic ...... ve 308 48. Trichocyclus Dumerilii, Esch. 4°. South Sea............ 354 49. Pelagia alba, Q. and G. Amboina .. divettects camer ney BOE: 50. Cymodocea diaphana, D’Orb. Atlantic......ccsscsseeeeeee 804 AA2 ’ 534 MANUAL OF THE MOLLUSCA. PLATE XV. All, except those marked *, are dorsal views. Terebratulide. 1. Terebratula maxillata, Sby. +4. Bath Oolite, England...... “363 2. diphya, F. Col. 4. Alpenkalk, Tyrol ........ 363 8. Terebratulina caput-serpentis, L. Norway—Medit. ........ 364 4. Waldheimia australis, Quoy. #%. Port Jackson............ 364 5. —————— impressa, Buch. Oxford clay, England ........ 365 6. Lyra Meadi, Cumb. 1816. §. U. Greensand, England .... 365 7. Terebratella Magellanica, Chemn. %. Cape Horn ........ 365 8. Trigonosemus Palissii, Woodw. Chalk, Belgium .......... 365 o. Meprerlia troncata,‘Lam..~ 2.‘ ~Medit. 5... 0.10.45 5 ee eee eee 367 10. Argiope decollata, Chemn, 2. Medit. .................. 368 11. Thecidium radians, Brongn. Chalk, Belgium.;............ 369 12. * hieroglyphicum, Defr. (interior). Chalk, Belgium 370 13. Stringocephalus.Burtini, Defr. var. 4. Devonian, Europe.. 371 Spiriferide. 14, Spirifera Walcotti; Sby. 4. Lias, Bath...........0ee0ee8 372 15. Cyrtia exporrecta, Wahl. U. Silurian, Europe ............ 372 16. Athyris lamellosa, Lév. 3. Carb. limes. N»Amer.—Europe 373 17. Uncites gryphus, Schl. 4. Devonian, Belgium............ 3/4 Rhynchonellide. 18.*Rhynchonella acuta, Sby. 3%. Lias, Europe ....... CPP 376 19. furcillata, Buch. Lias, Europe’... ...0 eee 376 20. ————_——- spinosa, Schl. 2. Inf. Oolite, Europe ...... 376 21. Atrypa reticularis, L. sp. 4}. Sil-Devon, N. Amer.—Europe 3878 22. Pentamerus Knightii, Sby. 4. U. Silurian ...2..4....... 377 Orthide. 23. Orthis rustica, J.Sby. 2. U. Silurian, Europe............ 380 24.*Strophomena rhomboidalis, Wahl. 3. U. Silurian, N. Amer. POO [ows hed h's ails eas + ewe baa. torea eee sip thoes 380 25. Lepteena liassina, Bouch. 2. Lias, Europe ........... ssi ROBE 26. Calceola sandalina, Lam. 3}. Devonian, Europe ........... 383 Productide. 27. Productus horridus, J. Sby. 34. Magn. limestone, Europe.. 384 28.*—————_ proboscideus, Vern. 3. Carb. limestone, Belgium 384 29. Chonetes striatella, Dalm. U. Silurian, Europe............ 386 Craniade. 30. Crania Ignabergensis, Retz. Chalk, Sweden .............- 386 Diseinide. (81. Discina lamellosa, Brod. 3. Peru ..cveseeeeeeveeees seta O88 Lingulide. r 32. Lingula anatina, Lam. 4. Philippines .........0.seseees 389 © PLAID, ie ssn . pir net, AELALSMIE de anne SP Wentmurd ? * = 7 ¥ ‘ s = ; 8 ae 8 : a, ’ i ee oo Y ' ; “ge _ t : i . ‘Ve yn ah x 2 y a) | , “a "ih ' } | | Oa a . 2 mK * psa A Aaa | ey i” a 4 a vs ¥ . rye ss a ; 7 7 " , ay ' a, j ‘ aS a “ , ‘ ae . o . Ps , ‘4 s Py 5 ie . 4 r j = . . at ce i b my 7). i .) ols i] a. . 7 . 4 ee ae fl) FZ; 4 ui “ill ar SP Woedwara. | Wey 4 TW. Lowry fo. ~ : EXPLANATION OF TOF PLATES. d90 PLATE XVI. Ostreide. 1, Ostrea diluviana, Gmelin. 4. Chalk-marl, Brit. .......... 407 ° 2. (Exogyra) conica, Sby. ‘2 U. Greensand, Wilts .. 408 3, Anomia Acheeus, Gray. 2. Kurachee, Scinde .. sia nitiorgsty £08 4, Placunomia macroschisma, Desh. }. California .......... 409 5. Placuna sella, Gm. sp. +. China,...:. SS Sees 409 6. plncenta, L. (young). N2Australia. < .. 6 4...c even 410 7. Carolia placunoides, Cantr. (hinge). Tertiary, Egypt ... .. 410 S- Pectenypiiea, L... 2.. .China,. ..<1|...5.. Bal ews Perec. 412 9. (Hemi-pecten) Forbesianus, Ad. 2. SoolooSea, 14 fms. 412 10. €Hinnites). pusio, Pen. 2: - Brite. Wise steers 412 11. Lima squamosa, Lam. 4. China........ area Sales oes eee 12. —— (Plagiostoma) cardiiformis, Sby. Bath Oolite, Brit. .... «12 13. ——-- (Limatula) sub-auriculata, Mont. Brit. ......... ee 413 14. —— (Limea) strigilata, Brocchi, sp. Pliocene, Italy ...... 413 15. Spondylus princeps, Gmel. +4. Sooloo Sea.......2.....05 413 as: (Ledum) spondyloides, Gmel. 2. Red Sea...... 414 £(7@ heatula eristata, Lam. 2. W. dndies”..). cecceesvswewvs 414 P Aviculide. ie eos hirundo, L.' 3. Medit. | ..:..0.sigsieccece Pain « ae 415 492 (Meleagrina) margaritifera, L. sp. 4. Ceylon .....% 416 20. ——— (WMaileus) vulgaris, Lam. +. China .....cceeereee 416 21. (Pulsella) lingulata, Lam. 4. Red Sea............ 416 29, Posidonomya Becheri, Bronn. Carb. Hesse, Brit........... 417 23. Pinna squamosa, Lam. 1. © Medity. eo ee SA tars 419 24. Crenatula viridis, Lam. 4. Chinese Seas ........ veo Nee aa a,w@ adductor impressions, * p, pedal muscles. g, suspensors of the gills. : _ 6, byssal foramen or notch. 536 MANUAL OF THE MOLLUSCA, _ * PLATE XVII. * The figures marked are left valves (interiors). Aviculide. Page 1. Gervillia anceps, Desh. 2. Neocomian, Brit. ..sicceve wees stL0 9. Perna ephippium, L. 4. W. Indies ...... cscccswass ssnseeio 3. Inoceramus sulcatus, Park, 2. . I — 2 eS Sm “ a Se ee oe, a dealing ga - - ih, 2 ad o-- fa ¢ Tc. ree ery —t Pao ae ce oe ana ESF - te cat, a ~~“ 2s Qin ay Fe a iy MS pit aoe at, Pe go ay pocorn 4 - : js ee ee « ag aT Poel pti, Oe Tee . ey Oe et ee een ~— ile Srintaieittesst are tents reason tg it, thats wii, “) 0 at # K & My Mae i Rea Bahk aes ms ee I . ; iene aa aE a Te BRAS ROCT ; ey! : ota flats hig Ault