. SM eA TESS 9, wt 1sGG fen ives : MISS RDIE =e a pi Ee y7 women yt Bsr asy “ts 4 Gg as a + <<, 4 ot ‘: aise) a ri ete gts ~ LIBRARY MUSEUM OF COMPARATIVE ZOOLOGY. “ASS. ‘era § WEN) \o De. See ox a eo ee i itso Inte he en t- ica |.» In h; I1,—English-Hebrew. By Profess oe is of ‘Civil mat Mntestasttaas stor ga argien og ie he Pric ata iN ita x aby Potetshine ot Spec eeding, and Late eal id's on with a pkKefe -& concise Ang! BEELER, F.G.S, Price 58. 61. EOE IPIRAIRILY NAW TULUS (apts Owen) Yy ly i = a, Sy’ Wy g Ye YY 7 a __ The mantle mw Hood 6___Its dorsal told 000 Latertor digtations e___ Mtdamnental Gland p— Tentacles g Shell muscle se Hive UU U_Siphor La SELMA i HIVE x Last (hamber J.Wolewny ie. MANUAL OF THE MOLLUSCA: A TREATISE OF RECENT AND FOSSIL SHELLS. BY Dr. S. P. WOODWARD, A.L8., TATE ASSISTANT-PALAONTOLOGIST IN- THE BRITISH .MUSEUM. Second nition, WITH AN APPENDIX OF RECENT AND FOSSIL CONCHOLOGICAL DISCOVERIES TO THE PRESENT TIME, By RALPH TATE, A.LS., F.GS. WITH NUMEROUS ILLUSTRATIONS, By A. N. WATERHOUSE anv J. W. LOWRY. | St LONDON: | | WIRTUE & CO., 26. IVY LANE. NEW YORK: VIRTUE AND YORSTON. 1368. PREFACH. Tris 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, Wirrram LonspsaLE— 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. Epwarp JF orsEs ; without whose approval he seldom added to, or deviated from, the practice and plan of the ‘‘ History of British Mollusca.” | That he was right in taking this course, has been sanctioned by the highest authority in this country ;—since the same scheme has been employed by Prof. Owey in the Hunterian Lectures and Catalogue. It has also been adopted by Dr. E. Barrourin the Madras Museum; by the Rey. Prof. Henstow, in his Report to the British Association on the Formation of Typical Collections; and by Prof. Morrrs in his Catalogue of British Fossils. It was the writer’s desire, by abstaining from the intro- iv PREFACE. duction of personal and peculiar views, and by adhering to whatever was well established and sanctioned by the best examples, to make the work suitable for the use of Natural History Classes in the Universities. To facilitate reference, and meet the most general require- ments, the number of large groups and genera of shells has been restricted as much as possible, and those less me 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 i ¢talics ; the writer’s own wishes coincide with those of the distinguished botanist Sir J. E. Surru, that ‘‘the system should not be encumbered with such names ;” but they have been admitted in deference to custom at general opinion.* The rules of the British Association, intended to secure uniformity, have called into existence a few active opponents, seeking to distinguish themselves by the employment of pre- Linnean and MS. names, on the pretence of carrying out the “law of priority’ (p. 48). But this folly has reached its height, and will fall into contempt when it has lost its novelty. The investigation of dates is the most disheartening work upon which the time of an author can be employed; it is never safe to take them second-hand, and even reference to the original works is not always satisfactory.t 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 “ Athenzum”’ 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 works of Gray, Philippi, Catlow, Adams, and other conchologisis ! 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. 3 sii PREFACE. Vv asthe value of species and genera, and the laws of gcoera- 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 accidental, and to detect the relations of phenomena, however widely separated and apparently unlike. In this way ‘‘la belle Science”? (as Mr. Gaskoin calls Con- chology !) may acquire the influence of pursuits more usually resorted to for mental development and discipline. : The wood-cuts have been principally executed by Miss A. N. Waterhouse, of Marlborough House, from original drawings by the Author; and although printed from stereo- types, they have the advantage of accurately representing what was wished to be shown. The engravings of Mr. Wilson Lowry speak for themselves ; many of the figures are from the specimens in his cabinet ; and the interest he has taken in the work will be seen in the eare 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 II. 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 little as possible with the Author’s original classification and systematic arrangement. A. ht. Sept., 1866. CONTENTS. PART TI. CHAPTER LI. : PAGE On tHe Position oF THE Moziiusca InN THE ANIMAL KincDom. © —Characters of the five primary groups, or sub-kingdoms :— Vertebrata— Mollusca—Annulosa— Coelenterata— Protozoa. MWEIE ANTIQUILY 2.6.60 ssicee es SehionooSs Breen cent: Ciasses oF Mozivscea.—l. Cephalopoda.—2. Gasteropoda.— 8. Pteropoda.—4. Brachiopoda.—. Lamellibranchiata ... 3—7 Hasits AND Economy oF THE Moiiusca.—Sedentary tribes, their mode of attachment; locomotive tribes, their means of pro- gression; situations frequented by shell-fishF ood: vege- table, infusorial, and animal feeders.—Use of shell-fish to other animals for food; use of shells for ornamental and other purposes; prices of shells.—Longevity of molluscous animals; tenacity of life; fecundity; oviposition ...... 7—15 STRUCTURE AND PuystoLoGy or THE Mozivusca.— Nervous system; organs of sense.— Muscular system.—Digestive system; linoual teeth; secretions.—Circulating system ; aquiferous canals.—Respiratory 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- eee IC VCLOPINOM G4. sie cieucibieseus ses echny coceda car's 15—45 OLAssiFicaTion.—Affinities; analogies; species; genera; families; the quinary system; synonyms; authorities; types; abbre- BGMASMI Gc aie loidig iw wine Gua e-have Sido ciel ciclo sont creiet al s\eieyniareich nee ee 1—3 CONTENTS. CHAPTER II. PAGE GEOGRAPHICAL Distrinution.—Land provinces; marine pro- vinces.—Specific areas; specific centres.—Generic areas; sub-generic areas.—Boundaries; influence of climate.—Origin OL GPrOVINCES | fin'e4 5 ac oes og ss ie. See Wel ee ee eee Marine Provinces.—Arctic genera; tropical genera; cosmopo-— TUGAN: SPECIES” 2.5. os 5,5 eoie oan sues 8 os sl cee ee eee i. Arctic Province. 142 8.0ste5-b eee eee II. Boreal Province: Norway, New England ........ ti.. Celtic Province: Britain, Denmark s-56-5 Soe ITV. Lusitanian Province: Portugal, Canaries, Madeira, Azores, Mediterranean, Black Sea ............ Wi. -Aralo=Caspian. Province Gia. soe cee eee VI. West-African Province ...... Sa OS ee Beets cea Soeus Vii. South-Atrican Province ee aero eee eee ee ee VIIT. Indo-Pacific Province: Red Sea, Persian Gulf .... IX. Australo-Zelandic Province: New South Wales, Pasmania, «iNew Zicalatmd amine eth, seme ttc. aie Xs) ssaponic de rovanee so meete eee eee Na aoe et ee xa Alentian! Provances Ochotsk, Sitka. cae cea ss Provinces on the Western Coast of America ...........0+--- XII. Californian Province ..... eae ere eters rae es XG. + Panamic Province "Galapacoss 4 ae toe aos ee XY. Peravaam Province: WIeAens cise ime tcote och aia XV. Magellanic Province: Falkland Islands .......... OV sie Mela fae onicm tenO Vice! seat eh ee terateledey Sicha tabele falece. sie MOVIL. “Caribbean Province’. 22 2. Jute. REE aie EG alee reams ailamigiC worO valle yt. tce lates ein aje te elele nels ,aee Lanp Recions.—Distribution of land and fresh-water shells ; genera of the Old and New World; arctic regions ........ AG Crmiamie ACO IOM: WUDELIA macie cle ees clays « oels oe dls eee 2, Lusitanian Region: Mediterranean Islands; Madeira, Azores, Canaries, Cape de Verdes, Ascension .... S.biclena ol righan d Acuna... 2.70 0 since aes ene tee PACH CAT ARCCOUOI 55 aig stapes ii ejaic else eyelets Wiehesiste = nels ee 3. Ae) MS AVE ARCO UOT coe) \c0aie oo) tr etie eco a's ast) alate Mpeialinrs 6 nie lare) int 5. Yemen—Madagascar: Comoro Islands, Seychelles, Mauritius, Bourbon, Rodriguez ...........+..+: 6. Indian Region: (Ceylon of 5.5 oss seks eee te oa i.) Whigs and Japan <..02 ccs week seine ee en ee eee 8. Philippine Islands 1.0... ccc eeee eee rect ee ce cea Do ANE. Meets Dats: = oo ne oat eaten gd erent afer Sig chek Ba Aag3: 0 CONTENTS. ix PAGE 11. Papua and New Ireland ....... Retvlepstae stelle oisaaiere LOG eS ECAN ATI INCOLOM, ¢ Wisc ssmisie'eelcye Geslewacelaves dis 103 fe eSouth Australia and Tasmania ..........sc++ses. 104 Me ee eAN IN te sind cia ain are alee mele Gf siath ate eaS eTOa 15. Polynesian Region: Salomons, New Hebrides, New Caledonia, Feejees; Friendly, Navigator’s, Society Islands; Low Coral Islands; Sandwich Islands 104 ie. Canadian Regions ; New-England ................ 106 RPP TLIC SAL OSS 6.5.5), 0 afci 8 aiejausieie e ties. io eviecwlr ewe stow «6 107 Per ORETORUCH IN PeCOTOI SLs 4 Stas Woe, ater barashee dtc gen of aod 108 nee Oremom and: Californias 6s 1boeceeale 1G delaw ono ee oats 109 ume EVCOTO Mah tras tac ava's doesn cbse hoitepioneisyn cote, b oleper ah 109 21 ANID ee SEARING Ae gelesen eng We aed Satpal 110 2yeeColumbian, Reston: Galapagos... is anc afb 20s s Te Pea aT IC STON, bel a eon ew ce de ae ores fa tea hh ull oh nar 112 Ammer EUR At, HeOVONMT. Seca. wiciae valeurs cine wk Ces ie is ee 113 PONE SCMLIMC MCOTOD, Fate wee bene ses we eee a eer ee 114 pone Owiiam tesion - Juan Permanden’ iy. calcd ese aes 2 114 27. Patagonian Region: Fuegia, Falklands ............ 115 CHAPTER, It. DistrizuTIon oF THE Morivsca In Time.—Geological Table; distribution of Species in the Strata; of Genera; table of Characteristic genera; table showing range of genera; range of families; numerical development in time.— Order of appear- ance of groups of shells; order of succession.—Migration of species and diffusion of Genera in former times.—Method of Geological investigation.—Tertiary Age.—Secondary Age.— Paleozoic Age.—Numerical estimate: living and fo8sil SRLS Mesias ais! a0 04 0) ad SPwietelate. diem vere Snares tai dUOFs)' Asanti s ney; CHAPTER IV. On Cortectinc Sueiis.—Land-shells; elevation on mountains, —Fresh-water shells.—Sea-shells, littoral species; floating: mollusca: the towing-net; trawling; kettle-nets; deep-sea fishery ; trapping whelks; dredging...........sesessseres 186 Dredging papers, by M‘Andrew and Barrett, Norway.......... 144 Wredeine papers, by Forbes, Aigean .......scceesbeceens 148 Zones of depth: littoral; laminarian; coralline; deep-sea coral EES. € cp die Eee CIC Rc ae OR oP era Oe 151 Preservation of Molluscous animals for examination ....+ece.ceece Lud x CONTENTS. | PARTY: Tf. SYNOPSIS OF THE GENERA. CHAPTER I. PAGE Crass I. CePHALOPODA. ORDER I. DIBRANCHIATA ..........+. 155 SECTION As. . OCTOPODA._. cians seme eee meee jaltatisauendcn anteetors 158 Fam,I. Argonautide.—Argonauta.. 2.06 ne desc ow ce codes» 161 Fam. II. Octopodide.—Octopus, Pinnoctopus, Eledone, Cir- roteuthis, Philonexis, Sceeurgus, Boliteena .............- 163 SECPION 45, DECAPODA, (0 dee ks cee PR elie ene tne ran" 166 Fam. III. TZeuthide.—Loligo, Gonatus, Sepioteuthis, Beloteuthis, Geoteuthis, Leptoteuthis, Cranchia, Sepiola, Loligopsis, Cheiroteuthis, Histioteuthis, Onychoteuthis, Enoploteuthis, Ommastrephes, Thysanoteuthis, Loliolus, Plesioteuthis, Dosidieus (20.0... .<.: . ob. 6oe eee Fam. IV. Belemnitide.—Belemnites, Belemnitella, Xipho- teuthis, Acanthoteuthis, Belemnoteuthis, Conoteuthis .... Fam, VY. Sepiade.—Sepia, Spirulirostra, Beloptera, Belem- mosis; Helicerus. S2 iiss is Roles ee ee eee Ram. VI. ° Sporulide.—Spirula 3.20202 eee ee see Orpen 11> TErRamRANGHIATA | 4-u.ce 6s Gee oe se oe Fam. I. Nautiliide.—Nautilus, Lituites, Trochoceras, .Cly- PUMOTATS, 64 sisi la ale si opal cae ea RE eee aie Be Rn Sao Fam. Il. Orthoceratide.—Orthoceras, Gomphoceras, Onco- ceras, Phragmoceras, Cyrtoceras, Gyroceras, Thoracoceras, INO GRO CERAS Heme ratty cable etlane seme eee inte ies ie as Ee Fam. III. Ammonitide.—Goniatites, Rhabdoceras, Bactrites, Ceratites, Ammonites, Crioceras, Toxoceras, Ancyloceras, Scaphites, Helicoceras, Turrilites, Hamites, Ptychoceras, JEUNE pelea mene a Mus eet ea Mean OE char errant =, AL APE 2 0 0S ee Eo oe CHAPTER IL. Cras die CART EROPODA thie: Sree see Eee ee Ghani Griore a. vie ROSOBR AN CHIATA (ott t ta cee tee Riek oe ee DEOTION AL CTEHONOSTOMATA 62 or fe onl wpe ee wis a eg Cah cave cues Fam. I. Stromiide.—Strombus, Pteroceras, Rostellaria, Seraphs eeose ee ee eeoeeeeeesee eereeeeeceonse eeseececee eeeeed 167 173 176 17? 178 185 190 195 209 209 CONTENTS. X1 PAGE Fam. II. Muricide.—Murex, Typhis, Pisania, Ranella, Triton, Fasciolaria, Turbinella, Cancellaria, Dibaphus, Tricho- Semeapeicrem by U ct. EVTSUIS, ve/ay0 s leaeses eels eph 9 89 a6. siala pes 9,6 we, ss Fam. JIT. Buccinide.— 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 .... Fam. 1V. Conide.—Conus, Pleurotoma, Cithara .......... Fam. V. Volutide.—Voluta, Cymba, Mitra, Volvaria, Mar- mEeTION Bb. HIOnLOSTOMATA if .0 020... SEAGIG ROIS oueie tect sri 3 Fam. JI. WNaticide.—Natica, Deshayesia, Naticella, Sigaretus, Lamellaria, Narica, Velutina, Cryptocella .............. Fam. Il. Pyramidellide.—Pyramidella, Odostomia, Chem- nitzia, Kulima, Monoptigma, Aclis, Styloptygma, Myonia, Leucotina, Stilifer, Loxonema, Macrocheilus ............ Fam. III. Cerithiade.—Cerithium, Potamides, Nerinza, Wasiweiella, Aporrhais, Struthiolaria .....c.00% .s00casees ‘Fam. IV. Melaniade.—Melania, Paludomus, Melanopsis Fam. V. Yurritellide.—Turritella, Ceecum, Vermetus, Sili- RUATIA OCHIATION Ss 6s nse 0's ba digaysitelspctecn eamer pa atm 5, alasag ens Fam. VI. JLittorinide.—Littorina, Solarium, Phorus, Lacuna, Litiopa, Rissoa, Skenea, Truncatella ?, Lithoglyphus .... Fam. VII. Paludinide.—Paludina, Ampullaria; Amphibola, “TESTER I) ots RN ge he Aer aie ete eS Fam. VII. WNeritide.—Nerita, Pileolus, Neritina, Navicella Fam. TX. TZurbinide.—Turbo, Phasianella, Imperator, Tro- - chus, Rotella, Monodonta, Delphinula, Adeorbis, Euom- pHalusocomatella, Broderiplay \\. ss «6s si ose Seve blo ae oe ee Fam. X. Haliot’s—Haliotis, Stomatia, Teinotis, Scissurella, Pleurotomaria, Murchisonia, 'Trochotoma, Cirrus, Ianthina Fam. XI. Sissureilide.—Fissurella, Puncturella, Rimula, mg emma, PACMOPMOLUS lee hese ss eis o a0 «stk s oyetem ms Fam. XII. Calyptreide.—Calyptrea, Crepidula, Pileopsis, BE OLIV Ge Pin o's Bj ure ere cise o apa uie pale olive we aetna ears Be Fam. XIII. Pateliide.—Patella, Acmea, Gadinia, Siphonaria iam SOY. Dentaliade.—Dentalium, ..,....0c.e0ceuscnes apie a OL icomdce.——CIGOM-,..... as «so a. spots co alee «> 2 + ae Xi CONTENTS. PAGE C.a:s II. Gastsropopa. Orper II. PuLMONIFERA.......+.0++ 285 WECTIONUA, » ENMOPHROULATAY (faz uso G ait e cuveu we a ee 285 Fam. I. Helicide.—Helix, Vitrina, Succinea, Bulimus, Achatina, Pupa, Cylindrella, Balea, Tornatellina, Paxillus, CHIC TIO STU Heat RI MER RIOR UIA Mr iis Aes ae oF Novae etenee ete 288 Fam. II. Limacide.—Limax, Anadenus, Incilaria, Arion, Parmacella, Janella, Aneitea, Parmarion, Triboniopherus, Waiguesnelia, Mesfacella. ov. 20... ws ee hemes eee eee ee 295 Fam. III. Oncidiade.—Oncidium, Vaginulus ............ 299 Fam. 1V. Limneide.—Limnea, Chilinia, Physa, Ancylus, DE LaMON DIS eae seen eyete sje ease es 0 gina nse wheat EERE ENE 3800 Fam. V. Awriculide.—Auricula, Conovulus, Carychium (Siphonaria) hice... Seog seo uRodar eos shedogsgmensicte ta ater: 303 SECTIONS, OPE RCUMADA “seca craxalesuh e osiele bia bvicin saath entillehet ons aera 3805 Fam. VI. Cyclostomide.—Cyclostoma, Ferussina?, Cyclo- phorus, Pupina, Eleliema; Shoastomar 1; .t./nctouelels.. hia 306 Fam. VII. Aciculide.—Acicula, Geomelania .............+. 310 _ OnveR TIT. OPisTHO-BRANCHIATA ....... oso! alin ae Meier 311 Sorin Ay | Eecri-peawemiaTs |. 120 0),2 >. 220 SS eee Fam. I. Zornatelide.—Tornatella, Cinulia, Ringicula, Glo- biconcha, Varigera, Tylostoma, Pterodonta ?, Tornatina?.. 312 Fam. II. Buillide.—Bulla, Acera, Cylichna, Kleinella?, Amphisphyra, Buccinulus, Aplustrum, Scaphander, Phi- line, Doridium, Gastropteron, Physema ................. 315 Fam. III. Aplysiade.—Aplysia, Dolabella, Stylocheilus, Dolabrifera, Siphonopyge, Notarchus, Icarus, Lobiger .... 320 Fam. IV. Pleuwrobranchide. — Pleurobranchus, Postero- brancheea, Runcina, Neda, Susaria, Umbrella, Tylodina .. 322 Fam. V. Phillidiade.—Phyllidia, Fryeria, Hypobranchiea, BByy ov aa AU ECOL es Mag et eet aid Fes b/s eh Aor a ra i 324 Section B. NvpIBRANCHIATA ..... Bel Rnb waaNepE et IA eee sehinyors ehe> coonaa 325 Fam. VI. Doride.—Doris, Heptabranchus, Hexabranchus, Atagema, Actinocyclus, Chromodoris, Asteronotus, Glos- sodoris, Goniodoris, Triopa, Augirus, Thecacera, Polycera, Idalia, Ancula, Ceratosoma, Trevelyana, Crimora, Pelagella, Gymnodoris, Acanthodoris, Casella, Brachychlamis ...... 328 Fam. VII. Tritontade.—Tritonia, Scyllea, Tethys, Bornella, - Dendronotus, Doto, Gellina, Meliboea, Lomanotus ...... 332 Fam. VIII. olide.—olis, Glaucus, Fiona, Embletonia, Calma, Favorinus, Galvina, Cuthonia, Filurus, Proctonotus, Antiopa, Hermza, Alderia, Chiorera ...cscscseceeseves 335 CONTENTS. m1} Fam. IX. Phyllirhoide,—Phyllirhoe .........eccececee.. 338 Fam. X. Hlysiade.—Elysia, Acteonia, Cenia, Limapontia, CPL TLE SS AT Ta Rs i te et ca 339 Weper PV. NUCLEOBRANCHIATA ............00 008 a Ai ae 340 Fam. I. rolide.—Firola, Carinaria, Cardiapoda ........ 342 Fam. II. Aélantide. Atlanta, Porcellia, Bellerophon, Cyr- poles. -Mackurea: 20)... Pace ves 08 Sapiens in ihvcate cused 343 See eH OP ODA’ |, .s.. si sie cw ce eat ane) selec wekte belo ks 846 Selene LETH COSOMATA % co. cscs crn aye aorneTse mee Be Cen cuateinh 348 Fam. I. Hyaleide—Hyalea, Cleodora, Cuvieria, Theca, terotheca, Conularia, Hurybia, Cymbulia, Tiedemannia. . Fam. UW. Limacinide.—Limacina, Spirialis, Cheletropis, Mac- FADE SUT a oa as ais =F help sskiege apes a. ni'5/Salofonalodbwepebslsohe cee ooo: Some NCNM OSOMATA« «2.0 si sus avec. e-cloncd 60 coc eos cosllaceue: Yetsleces LSE 5 LG UE Apr a Ce a tT 7 aR eet en CHAPTER III. ee ENE ACU TOPODAL 3)... oc ae adie win glace Sd welnmpeld a lamee sl gle Fam. I. Terebratulide.—Terebratula, Terebratella, Argiope, Pabecinpn SLEINSOCEPhalus ~~)... eats ects we ches wirelen « Fam. II. Spiriferide.—Spirifera, Athyris, Retzia, Uncites. . Fam. Jl. Rhynchonellide.—Rhynchonella, Pentamerus, SES DEY 1) Re RD ei See ere cn tr gee oS an aty AORN Fam. IV. Orthide.—Orthis, Strophomena, Davidsonia, Cal- ON MIMS ENE oe ie Zina Nagin + 0) 6 WD 'opeltana ahcced Shadere Sot pees Fam. V. Productide.—Productus, Strophalosia, Chonetes .. Ham. Vi. Craniade:--Crania, .... 00. bce ens lobes ee cena Fam. VII. Discinide.—Discina, Siphonotreta ..........4 Fam. VIII. Linguiide.—Lingula, Obolus............6.) a CHAPTER IV. PECAN Me ONC EUDEEIUA | 81551 5 3.) Gpamepoder a ehaleteteve colts aril aicinnleleegalevars o ¢ eget UNGER TTONDDA |), .\s sfeiecteingie ao ala wt ee re ee abd lalahare oie y alex Fam. 1. Ostreide.—Ostrea, Anomia, Placuna, Pecten, Lima, Spenevluce Piicabula, oF. he ac wees cnet eee ees aoe Fam. II. Aviculide.—Avicula, Posidonomya, Aviculo-pecten, Gervillia, Perna, Inoceramus, Pinna,........seeeeeeeees Fam. III. Mytilide.—Mytilus, Myalina, Modiola, Hippomya, Dreissena evsn0e007e2 Dee eee 02888 HF BFF Fe 8 oe eooeoev eevee 07080 420 wy . XIV “CONTENTS. PAGE Fam. ITV. Arcade.—Arca, Cucullea, Pectunculus, ame Nucula, Isoarca, Leda, Solenella, Solemya........4..... 424 Fam. V. Trigoniade.—Trigonia, Myophoria, Axinus, Cur- tonotus, Pseuddxinus, liyrodesma...\5... 2) see ee 430 ~ Fam. VI. Unionide.—Unio, Castalia, Anodon, Iridina, Myecetopus, -Autherta, Mulleria (oo. ..\c-sce. ee eee 432 Section B. SrHonrwa: Integro-pallialia ...........0ce0eseee 436 Fam. VII. Chamide.—Chama, Diceras, Requienia ........ 437 Fam. VIII. Hippuritide.—Qippurites, Radiolites, Capri mello, ‘Caprina.“Caprotima. -.'.s22 5 <2 teas. case hee ene 440 mam, 1,” “Pridacnde.-_Uridacna® . ou. aeons ea poe 451 Fam. X. Cardiade.—Cardium, Conocardium........,..... 453 Fam. XI. Lucinide.—Lucina, Corbis, Tancredia, Diplo- and donta, Ungulina, Kellia, Montacuta, Lepton, Galeomma 455 Fam. XII. Cycladide.—Cyclas, Cyrena, Cyrenoides ...... 461 Fam. XIII. Cyprinide.—Cyprina, Circe, Astarte, Gouldia, Crassatella, Isocardia, Cypricardia, Pleurophorus, Cardilia, Megalodon, Pachydomus, Pachyrisma, Opis, Cardinia. Myoconcha; Cardita, Verticordia ... -.27..)).0 ee eee 463 Section ©.. SrewonmaA;sSmu-palliala ...2...0--8 - aoe: 472 Fam. XIV. Veneride.-Venus, Cytherea, Meroe, Trigona, Artemis, Lucinopsis, Tapes, Venerupis, Petricola, Glau- COMAY A es oistos tee Pere ran PS ers SR oa. aes ube i 472 Fam. XV. WMactride.—Mactra, Harvella, Gnathodon, Lu- tratia, Amapinella ie Ji 00 2 Dae acetic ice leroy ene 477 Fam. XVI. TZellinide.—Tellina, Gastrana, Capsula, oud: stedtia, Psammobia, Sanguinolaria, oe Mesodesma, - mryilia. onax Galatea eeettan cae sere = ee c's ene 479. Fam. XVII. Solenide.—Solen, Cultellus, Solecurtus...... 486 Fam. XVIII. Myacide.—Mya, Corbula, Nezra, Thetis, Panopred, (Giliy GUMEIIS po .uioncm Fhe cies eter em sero amar 489 Fam. XIX. 5038 A MANUAL OF THE MOLLUSCA. P&T elie P , CHAPTER I. THE POSITION OF THE MOLLUSCA IN THE ANIMAL KINGDOM. Att 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. Vertebrze are a common feature amongst the Vertebrata, as this sub-kingdom is called; but they do not form an essential characteristic, as the name might seem to imply. Distinct organs are devoted to the functions of respiration and circu- lation; the sexes are generally distinct; each individual is generally developed from a single egg. Blood red. 2. In the second sub-kingdom, or 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 Lingula, 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 gangla which supply the foot and head. 3. The various tribes of insects, spiders, crabs, starfishes, echinoderms, entozoa, and worms, have no internal skeleton; — but to compensate for it, their outer integument is 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 neryous system consists of ganglia arranged in pairs in the middle line of the body. From this equal lateral development-ef the nervous centres Professor Owen calls the group Homogungliata. The nervous system is traversed by the alimentary canal. The radiated animals form a part of this sub-kingdom. 4. The next sub-kingdom comprises most of the polypes, such as sea-anemones, the fresh-water hydra, and corals, in which the general cavity of the body communicates freely with that of the digestive apparatus, on which account they are called Coelenterata. The soft parts forming the body wall are composed of two distinct membranes; there is no heart; no apparent special respiratory organ; and in most cases very ~ slight traces of a nervous system. 5, All the animals not combined in the above groups, such as the sponges, the foraminifera, and a large proportion of the _ microscopic animalcules, form the last sub-kingdom, named Protozoa. They are characterised by a general 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 on by means of a few organs. The greater the number of organs that are set apart to perform special functions the higher is the animal said to be. The evidence afforded by geological researches seems to show that the leading types of animal structure have existed from a comparatively early period in the history of the globe; and that all forms which haye 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 Fig. 1.* Oral aspect of a Cephalopod. Cephalopoda,+ 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,{ 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. * Fig. 1. Loligo vulgaris, Lam.}. From a specimen taken off Tenby, by J. S. Bowerbank, Esq. The mandibles are seen in the centre, surrounded by the circular 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. + Gaster, the under side of the body. § Fig. 2. Helix desertorum, Forskal. From a living specimen in the British Museum, March, 1850. ; | Fig. 3. Hyalea tridentata, Lam., from Quoy and Gaimard, 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 haye 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, haying 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.{ 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 (7, the cardinal muscles, by which the valves are opened). (1.) Dorsal valve. These woodcuts have been kindly lent by Mr. J. E. Gray. § ee eaitrasichinta, plate-gilled. 6 MANUAL OF THE MOLLUSCA. the Brachiopoda, form the sub-class of Molluscoida. In the first edition the Tunicata 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, to be guided by convenience, nor ‘‘ framed merely for the purposes of easy remembrance and communication.” The Fig. 7. A Bivalve.+ Fig. 8. A Tunicary.} 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. 3. From Forbes and Hanley. + Ascidia mentula, Miill. Ideal representation ; from a specimen dredged by Mr. Bowerbank, off Tenby. ; HABITS AND ECONOMY OF THE MOLLUSOA. 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 ial 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 Se eeienca, the sedentary tribes settle in the place they intend to occupy fan ing 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 like the snail, though some are much more active than others; the pond-snails can glide along the surface of the water, shell downwards; the nucleobranchs and pteropods swim in the open sea. The cuttle-fish have a strange mode of walking, head downwards, on their outspread arms; they can also swim with their fins, or with their webbed arms, or by expelling the water forcibly from their branchial chamber; the calamary can even strike the surface of the sea with its tail, and dart into the air like the flying-fish.—( Owen.) By these means the mollusca have spread themselves over every part of the habitable globe; every region has its tribe; every situation its appropriate species; the land-snails frequent moist places, woods, sunny banks and rocks, climb trees, or burrow in the ground. ‘The air-breathing limneids live in fresh-water, only coming occasionally to the surface; and the auriculas live on the sea-shore, or in salt-marshes. In the sea each zone of depth has its molluscous fauna. The limpet and periwinkle live between tide-marks, where they are left dry twice a day; the trochi and 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 litiopa 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 MOLLUSCA. 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 calyptreea, 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 univalyes 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 antediluyian banquets. This is on the shore, or on the bed of the sea; far away from land the carinaria 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 goerius 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 liying 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 (ap/ysia) 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 balan and sea-weed, and the ascidian with zoophytes, which form an effectual disguise; the dima 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, beg almost limited to self-preservation, the escape from danger, and the choice of food. An instance of something like social feeling has been observed in a 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 “nog goer be 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 eae to be caught, after finding that the enemy is lying in wait for him. On one other hand, Mr. Bowerbank has a curious example of ‘‘instinct at fault,’ in the fossil spine of a sea- urchin, which appears to haye been drilled by a carnivorous gasteropod. We have spoken of shell-fish as articles of food. 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 Cynrea 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 af 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 die in their second winter, for clusters of empty shells may be found, adhering to one another, under ivied walls, and in other sheltered situations; the animals having perished in their hybernation. Some of the spiral sea-shells live a great many years, and tell their age in a very plain and interesting man- ner, by the number of fringes (varices) on their whorls; the contour of the ranelia 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. IIL., fig. 3), to have lived and continued growing for many years. Many of the bivalves, like the mussel and cockle, attain their full growth in a year. The oyster continues enlarging his shell by annual “ shoots,”’ for four or five years, and then ceases to grow outwards; but very aged specimens may be found, espe- cially in a fossil state, with shells an inch or two in thickness. The giant-clam (tridacna), which attains so large a size that poets and sculptors have made it the cradle of the sea-goddess, must enjoy an unusual longevity; living in the sheltered lagoons of coral islands, and not discursive in its habits, the corals grow up around until it is often nearly buried by them ; but although there seems to be no limit to its life (though it may live a century for all that we know), yet the time will probably come when it will be overgrown by its neighbours, or choked with sediment. The fresh-water molluscs of cold climates bury themselves during winter in the mud of ponds and rivers; and the land- snails hide themselves in the ground, or beneath moss and dead leaves. In warm climates they become torpid during the hottest and driest part of the year. Those genera. and species which are most subject to this ‘summer sleep” are remarkable for their tenacity of life; and numerous instances haye been recorded of their importation from distant countries in a living state. In June, 1880, 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 having 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 imprisonmenis 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 haying 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.t This individual was fixed to a tablet in the British Museum on the 25th of March, 1846; and on the 7th of March, 1850, it was observed that he must have come out of his shell in the interval (as the paper had been discoloured, apparently in his attempt to get away) ; but finding escape impossible, had again retired, closing his aperture with the usual glistening film; this led to his immersion in tepid water and marvellous © recovery. Advantage was taken of this circumstance for making a sketch of the living animal (Fig. 2). The permanency of the shell-bearing races is effectually pro- vided for by their extreme fecundity; and though exposed to a hundred dangers in their early life enough survive to re-people the land and sea abundantly. The spawn of a single doris may contain 600,000 eggs (Darwin); a river-mussel has been esti- mated to produce 300,000 young in one season, and the oyster cannot be much less prolific. The land-snails cae fewer enemies, and lay fewer eggs. * «Tt was alive 498 days after it was taken from the pond; and im 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 mollusca 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 bulimi 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 lke 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 ot 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 movements. They have organs, by which food is procured and digested; a heart, with arteries and veins, through which their colourless fluids circulate; a 16 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 nerves convey impressions of sound; the olfactory, of odours; the gustatory, of flavours ; whilst the nerves of touch or feeling are widely diffused, and indicate in a more general way the presence of external objects. The nerves by which motion is produced are distinct from these, but so accompany them as to appear 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 PHYSIOLOGY OF THE MOLLUSCA. 17 simple structure, and perhaps only possesses sensibility of light without the power of distinct vision. The larval bivalves have also a pair of eyes in the normal position (Fig. 30) near the mouth ; but their development is not continued, and the adults are either eyeless, or possess merely rudimentary organs of vision, in the form of black dots (ocell7) along the margin of the mantle.* These supposed eyes have been detected in a great many bivalves, but they are most conspicuous in the scallop, which has received the name of argus from Poli on this account (Fig. 10). In the tunicaries similar ocelli are placed between the tentacles which surround the orifices. Sense of Hearing. In the highest cephalopods, this organ consists of two cavities in the rudimentary cranium which pro- tects the brain ; a small calcareous body or otolithe is suspended ese 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 * “Bach 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. } Pecten varius, L., from a specimen dredged by Mr. Bowerbank, off Tenby ; m, the pallial curtains; br, the branchiz. ¢ Fig. 11. Tentacle of Eolis 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, 7, ¢). 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 Hncephala the tongue is armed with spines, employed in the comminution of the food, and cannot possess a very delicate sense. The more ordinary and diffused sense of touch is possessed by all the mollusca ; it is exercised by the skin, which is everywhere soft and lubricous, and in a higher degree by the fringes of the bi- valves (Fig. 12), and by the fila- ments and tentacles (vibracula) of the gasteropods; the eye-— pedicels of the snail are evidently endowed with great sensitiveness in this respect. That shell-fish are not very sensible of pain, we may well believe, on account of their tenacity of life, and the extent to which they have the power of reproducing lost parts. Muscular System. The muscles of the mollusca are principally connected with the skin, which is exceedingly contractile in every part. The snail affords a remarkable, though familiar instance, when it draws in its eve: stalls by a process like the Fig. 12. Lepton squamosum.} * Mr. Owen regards the membranous upelle between the oral tentacles and ds front of the mouth, as the seat of the olfactory sense. See Fig. 51. t Fig. 12. Lepton squamosum, Mont., from a drawing by Mr. Alder, in the British Mollusca ; copied by permission of Mr. Van Voorst. STRUCTURE AND FHYSIOLOGY 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, /), 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 1s 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. 15. Dreissena.} 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 (Huzley); 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 Swrey timber-docks. Ff, foot ; 6, 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 columella, and sometimes divided, forming two spots. It corresponds to the posterior retractors in the bivalves. Digestive System. This part of the animal economy is all- important in the radiate classes, and scarcely of less consequence in the mollusca. In those bivalves, which have a large foot, the digestive organs are concealed in the upper part of that organ ; the mouth is unarmed, except by two pairs of soft membranous * Fig. 14. Cytherea chione, L., coast of Devon (original); 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, 7, ¢). 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 linguai 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 KA B Fig. 15. Lingual Teeth of Mollusca, — each other, or there are lateral teeth on each side of a median series. The teeth on the pleure are termed wuncini; they are extremely numerous in the plant-eating gasteropods (Fig. 15, A). 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. 7 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 cyprea europea; consisting of a median tooth and three uncini on each side of it. 2 MANUAL OF THE MOLLUSCA. tained between the jaws; at others, it isextremely 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 bir cra in 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 avegetable-feeder, the gizzard is armed with numerous small plates and spines. The stomach of some bivalves contains an instrument called Fig. 17. Guzzard of Bulla.t the « erystalline 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. + Fig. 17. Gizzard of bulla lignaria (original). Front and side view of a half- growr 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 molluscs 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 murex, 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 haye 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 brandaris, 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 phosphoraa, 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 itself, 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; and the foot in the lamellibranchiates is distended by means of the aquiferous canals, which they regard as a rudimentary kidney. Agassiz and Lacaze Duthiers, on the other hand, assert that there - is a connection between the two systems. The proof relied on by the former observers was that when a coloured injection was forced in through a vein, and an injection of a 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, 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 Transactwns, 1862. ® 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 very 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 essential in each case that the surface of the breathing-organ should be preserved moist. The process is more complete in proportion to the extent and minute sub- division of the vessels, in which the circulating fluid is exposed to the revivifying influence. The land-snails (pulmontfera) have a lung or air-chamber, formed by the folding of the mantle, over the interior of which the pulmonary yessels are distributed; this chamber has a Fig. 18. TZrigonza 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 ; 7, 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 seryes 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 even those in which the mantle is divided into two lobes, are provided with valyes 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 im moying, 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 inflected, * Fig. 19. Psammobia vespertina, Chemn. after Poli, reduced one-half. The arrows indicate the direction of the current; 7 s, respiratory siphon ; e s, excurrent siphon; , foot. i } 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 rapidJy. 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 itunes what function these tufts or papille perform, concludes that morphologically and physiologically they are not branchie. 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 fissurella, haliotis, and dentalium, where it escapes by a hole in the shell, far removed from the point at which it entered. Near this outlet are the anal, renal, and generative orifices. The cephalopods have two or four plume-like gills, sym- metrically placed in a branchial chamber, situated on the under- side of the body; the opening is in front, and occupied by a funnel, which, in. the nautilus, closely resembles the siphon of the paludina, but has its edges united in the cuttle-fishes. The free edge of the mantle is so adapted that it allows the water to enter the branchial chamber on each side of the funnel: its muscular walls then contract and force the water through the funnel, an arrangement chiefly subservient to locomotion.* Mr. Bowerbank has observed that the eledone makes twenty respiraticns 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 98 MANUAL OF THE MOLLUSCA. ORDERS, CLASSES. Dibranchiata. Owen. Tetrabranchiata. Owen. Nucleobranchiata. Bl. ENCEPHALA .-. .» « «4 Prosobranchiata. M. Edw. ; CEPHALOPODA, Pulmonifera. Cuv. GASTEROPODA. Opisthobranchiata. M, Edw. Aporobranchiata, BI. 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 ¢esta, ‘‘a shell”) in scientific books; and the popular name of ‘‘shell-fish,” though not quite accurate, cannot be replaced by any other epithet in common use. In one whole class, however, and in several families, there is nothing that would be popularly recognised as a shell. Shells are said to be external when the animal is contained in them, and internal when they are concealed in the mantle; the latter, as well as the shell-less species, being called 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 multivalves of old authors were articulate animals (cirripedes), erroneously included with the mollusca, which they resemble only in outward appearance. All, except the argonaut, acquire a rudimental shell before they are hatched, which becomes the nucleus of the adult shell ; it is often differently shaped and coloured from the rest of the shell, and hence the fry are apt to be mistaken for pee species from their parents. In cymba (Fig. 20) the nucleus is large and irregular; ee * Tn its most reduced form the shell is only a hollow cone, or plate, protecting the breathing organ and heart, as in limaz, 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 spirula the shell is reduced to this ner, STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 29 Jfusus antiquus it is cylindrical; in the pyramidellide it is oblique ; and it is spiral in carinaria, atlanta, and many limpets, which are symmetrical when adult. The rudimentary shell of the nudibranchs is shed at an early age, and never 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 unio pictorwm, cyclas henslowiana, and wecten 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, hike the Lizard in Cornwall, and similar tracts of magnesian- silicate in Asia Minor, there are no mollusca.—( Forbes.) The texture of shells is various and characteristic. Some, when broken, present a dull lustre like marble or china, and are termed porcel/anous ; others are pearly or nacreous; some have a fibrous structure ; some are horny, and others glassy and translucent. The nacreous shells are formed by alternate layers of very thin membrane and carbonate of lime, but this alone does not Fig. 20. Cymba.* * Fig. 20. Cymba proboscidalis, Lam., from a very young specimen in the cabinet of Hugh Cuming, Esq., 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 gederopus. 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 like the longitudes on the globe; in others they run in various directions; and in a few the lines on the same pearl have different directions, so that they cross each other. The nucleus frequently consists of a fragment of a brownish-yellow organic substance, which behaves in the same way as epidermis when treated with certain chemical re-agents. Sand is generally said to be the nucleus; but this is simply a conjecture which has gradually become regarded as a fact; it is quite the exception for sand to be the nucleus; as a general rule it is some organic substance. In some districts one kind of nucleus seems to be more common than another; at least, this is how the different results obtained by observers in different localities may be explained. Filippi (Sull’ origine delle Perle. Translated in Miller’s Archiv. 1856) found distoma to be the nucleus in many cases; Kuchenmeister found that the pearls were most abundant in the molluses living in the still parts of the river Elster, where the water-mites (limnochares anodonte) existed most nume- STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA, él 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 imtroducing 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. 7 \ 7 Ss aN e. \ Ny) \ VV \\) RR SWRA YS @ WAS CANN Ye : Fig. 21. Pinna. Fig. 22. TZerebratula. 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 jibrous 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 lke 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.- sMagnified 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 penna.—( Gray.) § The specific gravity of floating shells (such as argonauta and ianthina) is lower than that of any others.—(De la Beche.) 32 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 remoyal of their animal cement. In Fig. 7D ch& 24, a represents the outer, b EES iN the middle, and c the inner fi) UM Z 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 transyerse 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. )+ The argonaut-shell and the bone of the cuttle-fish have a peculiar structure; and the Hippurite is distinguished by a qs \\ ll DVM UL 2 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 particles, like the rocks in which they occur. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 30 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 helia sericea, or fringed with hairs as in ¢richotropis ; 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 inne scarf-skin 3 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 dissqlve them entirely if it were not for their protecting epidermis. As it is, we can often recognise fresh-water shells by the erosion of those parts where the epidermis was thinnest, namely, the points of the spiral shells and the umbones of the bivalves, those being also the parts longest exposed. Specimens of melanopsis and 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 removal of its inner whorls; im 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. C3 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 turbinidee. If the margin of a shell is fractured during the lifetime of the animal, the injury will be completely repaired by the re- production both of the epidermis and of the outer layer of shell. with its proper colour. But if the apex is destroyed, or a hole made at a distance from the aperture, it will merely be closed with the material secreted by the visceral mantle. Such inroads are often made by boring worms and shell, and even by a sponge (cliona), which completely mines the most solid shells. In Dr. Gray’s cabinet is the section of a cone, in whose apex a colony Fig. 25. Shetion! oi a ane neonatal 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 growth proper 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 ie spondylus some partsofthe mantle 78 76 Section hswehent secrete more than others, so that cavities, filled with fluid, are’left in the substance of the shell. The adult teredo and fistulana close the end of their burrows ; the pholadidea fills up the great pedal opening of its valves ; and the aspergillwm 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 rig. 27. Young is a marvel how they pass in and out, and how SORE ei 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 neritide 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 immer 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, euomphalus, turritella, and triton (Fig. 62). The deserted apex is sometimes very thin, and becoming dead and brittle, it breaks away, leaving the shell truncated or decollated. This happens constantly with the truncatelle, cylindrelle, and bulimus decollatus ; amongst the fresh-water shells it depends upon local circumstances, but is very common with pirena and cerithidea. Forms of shells. These will be described particularly under * This is sometimes done by the hermit-crab to the shell it occupies, STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. or. 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 cavities, 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 melanopsie, with whorls ribbed or keeled, as if through the unhealthy in- fluence of brackish water. The fossil periwinkles of the Norwich Crag are similarly distorted, probably by the access of fresh water; parallel cases occur at the present day in the Baltic. Reversed shells. Left-handed or reversed varieties of spiral shells haye been met with in some of the very common species, like the whelk and garden-snail. Buljmus citrinus is as often sinistral as dextral; and a reversed yariety 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. Bivalyes 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 heliz hortensis which got entangled in a nut-shell when young, and gtowing 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 umbo 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 spondylus and pecten pleuronectes) 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 danthina 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 ziziphinus.f * Cameos, in the British Museum, carved on the shell of cassis cornuta, are white on an orange ground ; one. tuberosa, and madagascariensis, white upon dark claret- colour; on c. 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, + Trochus ziziphinus, from the original, taken in Pegwell Bay abundantly. This species exhibits small tentacular processes, neck-lappets, side-lappets, tentacular filaments, and an operculigerous lobe. STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 39 and consists of horny layers, sometimes hardened with shelly matter (Fig. 28). It has been considered by Adanson, and more recently by Dr. Gray, as the equivalent of the dextral valve of the conchi- fera; but however similar in appearance, its anatomical relations are altogether different. In position it represents the 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 mornomyarian bivalves lie habitually on one side (like the plewronectide 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.¢ 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 t 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. t+ Compare /fissurella or trochus (Fig. 28) with lepton squamosum (Fig. 12). The disk of hipponyz 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 zanthina, which is secreted by the foot of the animal, and serves to /ioat the egg-capsules. 40 -MANUAL OF THE MOLLUSCA. 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- rupted.—( Miller.) i 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 papille, 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) mollusea ; 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 moneecious 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, equalling the parent ani- mal in bulk (Fig. 83). The f nidamental capsules of the yy y vee ha cuttle-fish are clustered \ like grapes, each con- taining but one embryo; those of the calamary are grouped in radiating masses, each elongated capsule containing 30 or 40 ova. The material with which the eggs are thus cemented together, or enveloped, is secreted by the nidamental gland, an organ largely developed in the female gasteropods and cephalopods (Fig. 50, n). Development. The molluscan ovum consists of a coloured yolk (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 like 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 epithelium on the surface of the embryonic mass; movements in the albumen become per- ceptible in the vicinity of the cilia, and they increase in strength, until the embryo begins to revolve in the surrounding fluid.t Fig. 29. Spawh of Doris.* * Nidamentai ribbon of Doris Johnstont. (Alder and Hancock.) } 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! { According to the observations of Professor Lovén (on nae bivalve mollusca), the ova are excluded immediately after the inhalation of the spermatozoa, and apparently from their influence ; but impregnation does not take place within the ovary itself. The spermatozoa of cardium pygmeum were distinctly seen to penstrate, in succession the outer envelopes of the ova, and arrive at the vitellns, when they dis- appeared. With respect to the “germinal vesicle ;” according to Barry, it first. 42 MANUAL OF THE MOLLUSOA. 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 seteze 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 setz, 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 twoeyes. The anterior half was occupied by four pairs of cylindrical arms, surrounding a round knob, at the summit of which was the mouth. Locomotion was effected by means of the cilia enveloping the arms, which impelled the animal through the water with the mouth fore- most. No circulatory or reproductive organs could be detected. The young bivalves are hatched before they leave their parent. - (See page 393) The forms they pass through present distinct differences in several families, so that even in the present state of embryological knowledge, some five or six types of development are known. Even in the same family there may bea great dis- approaches the inner surface of the vitelline’ membrane, in order to receive the influence of the spermatozoa ; it then retires to the centre of the yolk, and undergoes a series of spontaneous subdivisions. In M. Lovén’s account it is said to ‘‘ burst” and partially dissolve, whilst the egg remains in the ovary, and before impregnation; it then passes to the centre of the yolk, and undergoes the changes described by Barry, along with the yolk, whilst the nucleus of the germinal vesicle, or some body exactly 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. * Archiv fiir Anatomie und Physiologie, 1860, p. 72; see also Annals of Nat. Hist. for 1860. 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 Crenella 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 fayourably for vision, on the border of the mantle. The development of the young has been noticed in many of the genera of Pteropods. They are divisible into two groups: those in 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 ; J, flagellum ; vv, valves; m, ciliated mantle. - 7 Fig. 80*. Fry of mytilus edulis, after Lovén. e, eye; e’, auditory capsule; 7 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'cpoda produce large eggs, con- taining sufficient nutriment to support the embryo until it has attained considerable size and development ; thus, the newly- born cuttle-fish has a shell half an inch long, consisting of several layers, and the 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 egg. 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 deveiopment, 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 ; b, branchie ; h, heart ; v, vent; J, liver; 7, 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. * Ego 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 unspoken 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- fastly maintained, that the ‘‘ unity of organisation” manifested by the animal world results from the design of a Supreme In- telligence, and cannot be ascribed to the operation of a mechani- cal “law.” CLASSIFICATION. The objects of classification are, first, the convenient and in- telligible arrangement of the species ;* and, secondly, to afford & summary, or condensed exposition, of all that is known re- specting their structure and relations. In studying the shell-fish we find resemblances of two kinds. First, agreements of structure, form, and habits; and, secondly, resemblances of form and habits without agreement of struc- ture. The first are termed relations of affinity ; the second, of analogy. Affinities may be near, or remote. There is some amount of 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 “‘ ocythoe.” te. g. Aporrhais 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 siligua and ensvs. | 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 avail, and we are compelled to seek for more constant and comprehen- sive signs in the phases of embryonic development, and the condition of the circulating, respiratory, and neryous systems. Species. All the specimens, or individuals, which are so much alike that we may reasonably believe them to have descended from a common stock, constitute a species. It isa 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 seemed more desirable, in the present state of our knowledge, than a subdivision into very numerous families, without assignable, characters. CLASSIFICATION. 47 The orders and classes of mollusca have already been referred to; those now in use are in most cases natural. It has been sometimes asserted that these groups are only scientific contrivances, and do not really exist in nature 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 eyery part of the animal organisation ; and, as far as their information enabled them, they have made their systems expressive ‘‘of all the highest facts or generalisations in natural history.” —( Owen. M. Milne Edwards has remarked, that the actual appearance of the animal kingdom is not like a well-regulated army, but like the starry heavens, over which constellations of various — magnitude are scattered, with here and there a solitary star which cannot be included in any neighbouring group. This is exceedingly true; we cannot expect our systematic groups to have equal numerical yalues,* 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 have directed their researches to the discovery of that ‘‘reflection of the Diyine mind.” Some haye fancied that they have discovered it in a mystic number, and have ac- cordingly converted all the groups into fives.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.t * The numerical development of groups is inversely 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. t 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 Linnzus; therefore no scientific names date further back than his works. In the con- struction of these names the Greek and Latin languages are preferred by the common consent of all countries. Synonyms. It often happens that a species is named, or a genus established, by more than one person, at different times, and in ignorance of each other’s labours. Such duplicate names are called synonyms ; they have multiplied amazingly of late, and are a stumbling-block and an opprobrium in all branches of natural history.* One very common estuary shell rejoices in the following variety of titles :— Scrobicularia piperata (Gmelin sp.). Trigonella plana (Da Costa). Mactra Listeri (Avuct.). Mya Hispanica (Chemnitz). Venus borealis (Pennant). Lutraria compressa (Lamarck). Arenaria plana (Megerle). As regards specific names, the earliest ought certainly to be adopted, with, however, the following exceptions :— 1. MS. names; which are admitted by courtesy. 2. Names given by writers antecedent to Linnzeus. 3. Names unaccompanied by a description or figure. 4. Barbarisms ; or names inyolying error or absurdity.t It is also very desirable that names having a general (HKuro- pean) acceptation should not be changed on the discovery, 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- Opistho- Proso- Aporo- Pulmo- Pallio- Lamelli- Hetero-branchiata. [ZOOPBYTES. } * In Pfeiffe~’s Monograph of the Helicide, a family containing seventeen genera, no less than 330 generic synonyms are enumerated ; to this list Dr. Albers, of Berlin, has added another hundred of his own invention! + This subject was investigated and reported upon by 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 Linnzeus 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. Litym., etymology; Syn., synomym; Distr., distribution ; MS., unpublished ; Sp., species; B. M., in the British Museum. Distr., Norway—New Zealand; including all intermediate seas. Foss., Lias-chalk: implies that the genus existed in these and all intermediate strata. Chalk—; means that the genus has existed from the chalk up to the present time. Depth—s50 fins. implies that the genus is found at all depths between low-water mark and 50 fathoms. A fathom = 6 feet. 4, one-fourth real size; #, magnified four times. Lat., breadth; Long., length; Alt., height or thickness. Unc., an inch; Lin., a line or ~; of an inch; Mill., a milli- metre or +; of an inch. * Several bad practices—against which there is, unhappily, no law—should be strongly discountenanced. First, the employment of names already in familiar use for other objects ; such as cidaris (the title of a well-known genus of sea-urchins) for @ group of spiral shells; and arenaria (a property of the botanists) for a bivalve. Secondly, the conversion of specific into generic titles, a process which has caused endless confusion ; it has arisen out of the vain desire of giving new designations to old and familiar objects, and thus obtaining a questionable sort of fame, 50 MANUAL OF THE MOLLUSCA. CHAPTER II. GEOGRAPHICAL DISTRIBUTION OF THE MOLLUSCA. It is one of the most familiar facts in Natural History that many countries possess a distinct Fauna and Flora, or assem- blages of animals and plants peculiar to themselves; and it is equally true, though less generally understood, that the sea also has its provinces of animal and vegetable life. The most important or best known of these provinces are indicated on the accompanying map; different names, in some instances, and different letters and numbers, being employed to distinguish the marine from the terrestrial regions.* The division of the surface of the globe into natural history provinces ought to be framed upon the widest possible basis. The geographical distribution of every class of animals and plants should be considered in order to arrive at a theory of universal application. The most philosophical division of the globe into natural provinces has been by Swainson in 1835, and by Dr. Sclater in 1857. The last has been adopted by several naturalists. It was based upon a consideration of the distribution of birds, and has been extended to fishes and amphibia by Dr. Gunther. It might be extended to mollusca. In Dr. Sclater’s scheme the world is divided into six regions, viz. (1) Paleearctic region: this comprises Europe, North Africa, Asia Minor, Persia, Asia north of the Himalayas, North China, and Japan; (2) Ethiopian or Western Palzeotropical region, includes Africa south of the Atlas, Madagascar, Mascarene, Arabia; (3) Indian or Middle Paleeotropical region, including Asia south of the Himalayas, Ceylon, Burmah, Malacca, Southern China, Philippines, Borneo, Java, Sumatra, and adjacent islands; (4) Australian or Western Palezeotropical region: Australia, New Guinea, New Zealand, and the Pacific Islands ; (5) Nearctic or North American region: Greenland, and North America as far as the centre of Mexico; * The author regrets that, on account of the expense, this map appears without the advantage of colours. He would recommend those who are sufficiently interested in the subject to colour their own copies, distinguishing the shores of the marine provinces by the following tints :— Blue. 1. Arctic province; 15. Magellanic. Green, 2. Boreal; 11. Aleutian; 5. Aralo-Caspian. Oranye. 3. Celtic. Purple. 4. Lusitanian; 10. Japonic; 12. Californian; 18. Trans-Atlantic. Yellow. 6. W. African; 8. Indo-Pacific ; 13. Panamic; 17. Caribbean. Lake. 7%. S. African; 9. Australo-Zealandic; 14. Peruvian; 16. Patagonian. ten lwotmeris joltenia Lvonsia. te. 5 Gill. . is 0G Gonatus. Natica piplarta largarita_—---"\ SUT Ttmahida Feet 5 — dora. peas llra' rs ini yp | arctic i} Be I 2 | pina » Spoialia ee Pyne TAS 5 Ret oF ernie é y : Patel atella au | Aleutian tndzw| Saatdornas pap dane )Lellina Donam § Titoviria__/ Pete = 4 fala tis 12 Californian | Platyoden > i 4 NS ((Siguretus ~ V Comes Ohi I cptauila 5 N25, ‘%, 6 bs. Eel aiBezna dacna aan agerfigia Terebra. 0. | 6 Sona t TTT. 5S A LN Arg nodosa. 8, Inido-Pag Ony ch Ary argo ~1 pf Atlantis Cuvtora. Cress VF Gitene ¢ Tetaria acum leit, 7 LOVE g, oe oa Julian. Meleagrina Pteroceras Steumibnis Tpraicuro Triton 2 Tirat of adrift Tew 15 Magellanic ~\ et Modinta: Ma. | Bucciraum = 1D Voluta, 1 to 27 Land Provinces \\ bs Atrican Ommnastrephes —* Queyia 2! IP ek G has ella MOLLUSCAN PROVINCES enaninen ° ee | 018 Marine Proviuees — Crante Garrents. --Mountains Ter. Australian 2p pul” » Patella, 0 q 2/0 alo GEOGRAPHICAL DISTRIBUTION. 51 |(6) Neotropical or South American region: West India Islands, South Mexico, Central and South America, Galapagos, and |Falkland Isles. These divisions apply to the land, but it is | probable that they will help to throw light on the boundaries of the natural marine provinces. As will be seen, each of the above regions includes several of the provinces adopted in this work. The Land Provinces hitherto proposed have been chiefly founded on botanical grounds, but the evidence afforded. by insects and the higher classes of animals contirms the existence of these divisions. | The Marine Provinces have also been investigated by botanists ; and the striking peculiarities of the fisheries have been taken into account as well as the distribution of shell-fish and corals. In order to constitute a distinct province it is considered necessary that at least one-half the species should be peculiar, a rule which applies equally to plants and animals. Some genera i‘ and sub- -genera are limited to each province, but the propgwan ‘is different in each class of animals and in plants.* Specific areas. Species vary extremely in their range, some being limited to small areas, while others, more widely diffused, unite the local populations into fewer and larger groups. ‘Those species which characterise particular regions are termed “endemic ;” they mostly require peculiar circumstances, or possess small means of migrating. The others, sometimes called ‘‘ sporadic,” possess great facilities for diffusion, like the lower orders of plants propagated by spores, and more easily meet with suitable conditions. The space over which a species is distributed is called a ‘‘ centre,” or, more properly, a specific area. The areas of one-half the species are smaller (usually much smaller) than a single province. In each specific area there is frequently one spot’ where indi- viduals are more abundant than elsewhere; this has been called the ‘‘ metropolis” of the species. Some species which appear to be nowhere common can be shown to have abounded formerly ; and many probably seem rare only because their head-quarters are at present unknown.—(forbes.) Specific centres are the points at which the particular species are supposed to have been created, according to those who believe that each has originated from a common stock (p. 46) ; * The genera of plants amount to 20,000, and consist on an average of only four Species apiece! The genera of shells commonly admitted are only 400 in number, and average forty species each. It follows that the areas of the molluscan genera (ceteris _ paribus) ought to be ten times as great as those of plants. 52 MANUAL OF THE MOLLUSCA. these can‘ only be known approximately in any case. The doctrine that each species originated from a single individual, or pair, created once only, and at one place, derives strong con- firmation from the fact that so ‘‘many animals and plants are indigenous only in determinate spots, while a thousand others might have supported them as well.’”’* Generic areas. Natural groups of species, whether called genera, families, or orders, are distributed much in the same manner as species; + not for the same reason, since their con- stituents are not related by descent, but apparently from the intention of the Creator. Sub-generic areas are usually smaller than generic; and the areas of orders and families are, as a matter of course, larger than those of the included genera. But it is unecessary to remember that groups of the same denomination are not always of equal value ; and since species vary in range it often happens that specific areas of one class or family are larger than generic areas of another. The smallest areas are usually those of the forms termed aberrant; the typical groups and species are most widely distributed.—( Waterhouse.) ‘‘When a generic area includes a considerable number of species, there may be found within it a point of maximum (metropolis), around which the number of species becomes less and less. A- genus may have more centres than one. It may have had unbroken extension at one period, and yet in the course of time and change, may have its centre so broken up * Mrs. Somerville’s Physical Geography, li. 95. + “‘ What we call class, order, family, genus, are all only so many names for genera of various degrees of extent. Technically a genus is a group to which a name (as Ribes) is applied: but essentially, Hxogens, Ranunculacee, Ranunculus, are genera of different degrees. “One of the chief arguments in favour of the naturalness of genera (or groups), is that derived from the fact that many genera can be shown to be centralised in definite geographical areas (Erica, for example); z.e. we find the species gathered all, or mostly, within an area, which has some one point where the maximum number of species is developed. “ But, in geographical space, we not unfrequently find that the same genus may have two or more areas, within each of which this phenomenon of a point of mazimum number of species is seen, with fewer and fewer species radiating, as it were, from it. “ In time, however (or, in other words, in geological distribution), so far as we know, each generic type has had an unique and continuous range. When once a generic type has ceased it never re-appears. “A genus is an abstraction, a divine idea. The very fact of the centralisation of groups of allied species, z.e. of genera, in space and time, is sufficient proof of this. Doubtless we make many so-called genera that are artificial; but a true genus is natural; and, as such, is not dependent on man’s will.’—. Forbes. (See An. Nat. Hist. July, 1852, and Jan., 1855, p. 45.) GEOGRAPHICAL DISTRIBUTION. 538 that there shall appear to be out-lying points. When, how- eyer, the history of a natural genus shall have been traced equally through its extension in time and space, it is not impossible that the area, considered in the abstract, will be found to be necessarily unique.” —(Forbves.) To illustrate the doctrine of the unity of generic areas Professor Forbes has given several examples, showing that some of the most exceptional cases admit of explanation and confirm the rule. One of these relates to the genus Mitra, of which there are 420 species; it has its metropolis in the Philippine Islands, and extends by the Red Sea to the Mediterranean and West Africa, the species becoming few, small, and obscure. Far away from the rest a single species is found on the coast of Greenland. But this very shell occurs fossil in Ireland along with another mitra now living in the Mediterranean. Another case is presented by the genus Panopeea, of which the eleven living species are widely separated. Of this genus above 100 fossil species are known, distributed over many places within the wide area, on whose margin the relics of this ancient form of life seem to linger lke the last ripple of a circling wave.* According to this view the specific centres are scattered thickly over the whole surface of the globe ; those of the genera more thinly distributed ; and the points of origin of the large groups become fewer in succession, until we have to estimate the probable position or scene of creation of the primary divisions themselves; and are led to speculate whether there may not have been some common focus—the centre of centres —from which the first and greatest types of life have emanated. Boundaries of Natural History Provinces. The land provinces are separated by lofty mountains, deserts, seas, and climates; whilst the seas are divided by continents and influenced by the physical character of coast-lines, by climates and currents. ‘These ‘‘natural barriers,” as they were called by Buffon, retard or altogether prevent the migrations of species in particular directions. Influence of Climate. Diversity of climate has been the popular explanation of most of the phenomena of geographical distribution, because it is so well known that some species require a'tropical amount of warmth, whilst others can endure a great variety of temperature, and some only thrive amidst the rigours of the arctic regions. The character of the vegeta- tion of the zones of latitude has been sketched by Baron Hum- * The most striking and conclusive instances may be met with in the distribution of the highest classes of vertebrate animals, 54 MANUAL OF THE MOLLUSCA. boldt ; Fabricius and Latreille have divided the world into) climatal Insect-provinces; and Professor EH. Forbes has con- structed a map of the homoitozoic belts or zones of marine life. To all these the remark of Mr. Kirby is applicable—that any division of the globe into provinces, by means of equivalent’ parallels and meridians, wears the appearance of an artificial and arbitrary system, rather than of one according to nature. Professor Forbes has been careful to point out that although the ‘‘ Faunas of regions under similar physical conditions bear a striking resemblance to each other’—this resemblance is produced, ‘‘not by identity of species, or even of genera, but | by representation”? (p. 45). : Origin of the Natural History Provinces. Mr. Kirby appears to have been the first to recognise the truth that physical conditions were not the primary causes of the zoological pro- vinces, which he ‘“‘ regarded as fixed by the will of the Creator, rather than as regulated by isothermal lines.” * Mr. Swainson also has shown that the ‘‘ circumstances connected with tem- | perature, food, situation, and foes, are totally insufficient to account for the phenomena of animal geography,” which he attributes to the operation of unknown laws.t The most important contribution towards a knowledge of these ‘‘ unknown laws” has been made by Professor E. Forbes, who was perhaps the first naturalist ever in a position to avail himself of the great storehouse of facts accumulated by geolo- gists, respecting the distribution of organic life in ‘‘ the former world.” This subject will be referred to again in connection with the subject of Fossil Shells; meanwhile it may be stated that, according to this evidence, the Faunas of the Provinces are of various ages, and that their origin is connected . with former (often very remote) geological changes, and a different distribution of land and water over the surface of the globe. MARINE PROVINCES. Amongst the genera of marine shells there are some which have been considered particularly indicative of climate. From the Arctic list the following may be taken as examples of the shells of high latitudes; those marked * being found in the southern as well as in the northern hemisphere :— : * Introduction to Entomology. } Treatise on Geography and Classification of Animals, Lardner’s Cabinet Cyclo- pzedia, MARINE PROVINCES. 55 Buccinum. Velutina. *Crenella. *Chrysodomus. Lacuna. *Yoldia. *Trophon. *Margarita. *Astarte. Admete. — Cyprina. *Trivhotropis. *Rhynchonella. Glycimeris. The following have been thought peculiar to the warmer re- gions of the sea: Nautilus. Conus. Columbella. Perna. Rostellaria, Harpa. Cyprzea, Vulsella, Triton. Oliva. Nerita. Tridacna. Cancellaria, Voluta. Spondylus. Crassatella. Terebra. Marginella. Plicatula. Sanguinolar a. But it must not be inferred that these genera were always characteristic of extreme climates. On the contrary, the whole of them have existed in the British seas at no very remote geo- logical period. LRhynchonella and Astarte were formerly ‘‘ tropi- cal shells ;” and since the period of the English chalk-formation there have been living Nautili in the North Sea, and Cones and Olives in the ‘‘ London basin.” It is not true that the same species have been at one time tropical, at another temperate, but the genera have in many instances enjoyed a much wider range than, they exhibit now. - Some of the ‘‘tropical”’ forms are more abundant and extend farther in the Southern hemisphere ; several large Volutes range to the extremity of South America, and the largest of all inhabits New Zealand. The tropical and sub-tropical provinces might be naturally grouped in three principal divisions, viz., the Atlantic, the Indo-Pacific, and the West-American,—divisions which are bounded by meridians of longitude, not by parallels of latitude. The Arctic province is comparatively small and exceptional ; and the three most southern Faunas of America, Africa, and Australia differ extremely, but not on account of climate. If only a small extent of sea-coast is examined, the character of its mollusca will be found to depend very much upon the nature of the shore, the tides, depth, and local circumstances, which will be referred to again in,another page. But these peculiarities will disappear when the survey is extended to a region sufficiently large to include eyery ordinary variety of condition. It has been stated that each Fauna consists of a number ot peculiar species, properly, more than half;'and of a smaller number which are common to some other provinces. By ascer- taining the direction of the tides and currents, and the circum- stances under which the species occur, it may be possible to determine to which province these more widely diffused mollusca 56 MANUAL OF THE MOLLUSCA. originally belonged. And when species occur both recent and fossil it is easy to perceive the direction in which their migra- tions have taken place. The Fauna of the Mediterranean has been critically examined by Prof. Forbes and M. Philippi, with this result,—that a large proportion of its population has migrated into it from the At. lantic, and a smaller number from the Red Sea, and that the supposed peculiar species are diminishing so rapidly with every new research in the Atlantic, that it can no longer rank as a province distinct from the Lusitanian. When the Faunas of the other regions have been tested in the same manner, and disentangled, the result will probably be the establishment of a much greater number of provinces than we have ventured at present to indicate on the map. It may be desirable to notice here the extraordinary range attributed to some of the marine species. These statements must be received with great hesitation; for when sufficiently investigated, it has usually proved that some of the localities were false, or that more than one species was included. The following are given by Dr. Krauss in his excellent monograph of the South African Mollusca :— Ranella granifera : Red Sea, Natal, India, China, Philippines, New Zealand. Triton olearius : Brazil, Mediterranean, Natal, Pacific. Purpura lapillus: Greenland, (Senegal, Cape). Venus verrucosa: (W. Indies), Brit. Senegal, Canaries, Mediterranean, Red Sea, Cape (Australia). Octopus vulgaris: Antilles, Brazil, Europe, Natal, Mauritius, India. Argonauta argo: (Antilles), Medit., Red Sea, Cape. Lucina divaricata is said to be ‘‘ found on the shores of Europe, India, Africa, America, and Australia.” (Gray.) In this case several species are confounded. The rock-boring Saxicava has been carried to all parts of the world in ballast, and it remains yet to be ascertained whether the same species occurs in a living state beyond the Arctic Seas and North Atlantic. Lastly, the money cowry is always catalogued as a shell of the Mediterranean and Cape, although its home is in the Pacific, and it has no other origin in the Atlantic than the occasional wreck of one of the ships in which such vast quantities of the little shell are annually brought to this country to be exported again to Africa. ARCTIC PROVINCE. 57 I. ARcriIc PROVINCE. The North Polar Seas contain but one assemblage of Mollusca, whose Southern limit is formed by the Aleutian Islands in the Pacific, but in the North Atlantic is determined chiefly by the boundary of floating ice, descending as low as Newfoundland on the West, and thence rising rapidly to Iceland and the North Cape. A very complete general account of the Arctic Mollusca is given by Dr. Middendorff;* those of Greenland have been catalogued and described by Otho Fabricius and Moller ;+ and more recently by Moérch ;{ 158 species are enumerated by Middendorff, and 202 by Mérch. Scattered notices occur in the Annals of Natural History,§ and the Supplements to the Narratives of the Arctic Voyagers,—Phipps, Scoresby, Franklin, Back, Ross, Parry, and Richardson. The existence of the same marine animals in the Kamtchatka Sea and Baffin’s Bay was long since held to prove at least a former North-West passage ; but the occurrence of recent sea-shelis in banks far inland rendered it probable that even recent elevation of the land in Arctic America might have much reduced the passage. During the ‘‘ Glacial period,” this Arctic Sea, with the same fauna, ex- tended over Britain ; over Northern Europe, as far as the Alps and Carpathians; and over Siberia, and a considerable part of North America. The shells now living in the Arctic Seas, are found fossil in the deposits of ‘‘ Northern Drift,” over all these countries ; and a few of the species yet linger within the bounds of the two next provinces, especially in tracts of unusual depth. The Arctic shells have mostly a thick greenish epidermis (p. 33); they occur in very great abundance, and are remarkably subject to variation of form, a circumstance attributed by Professor E. Forbes to the influence of the mixture of fresh water produced by the melting of great bodies of snow and ice. ARCTIC SHELL-FISH. R. Russian Lapland. F. Finmark. I. Iceland. G. Greenland. D. Davis Straits (west coast). B. Behring’s Straits. O. Ochotsk. * British species (living). ** British species (fossil), Octopus granulatus. G. | amcena. G. Cirroteuthis Miilleri. G. “Qainnasng thax todarus. F. Newf. Rossia palpebrosa. G. P. Regent Inlet. Onychoteuthis Bergii. F. B. Limacina arctica, G. O. os Fabricii. G. * Malaco-zoologia Rossica; Mem. del’ Acad. Imp. des Sc. Petersb. T. 6, pt. 2, 1849. + Index Molluscorum Groenlandiz. Hafn. 1842. } Fortegnelse over Grénlands Bliéddyr in H. Rink: Grénland geographisk og statise tisk beskrevet, ii. Bind. 1857. § Hancock, An. Nat. Hist. vol. 18, p. 823, pl. 5. Ds 58 MANUAL OF Spirialis stenogyra. F. 5) balea. G. *Clio borealis. N. Zemia. G. *Nassa incrassata. F. *Buccinum undatum, var. Kara. O. eo hydrophanum, D. Prince Regent Inlet. + tenebrosum. R, G. B. * 5 Humphreysianum, R. G. em + cyaneum. F. D. G. Icy C. St. Lawrence. a glaciale. Kava, O. C. Parry. G. Spitzbergen. Buecinum angulosum. N. Zemla. Icy C. Spitz. 5 tenue. N. Zemla. G. 9 Groenlandicum. D. a undulatum. G. on scalariforme. G. es ciliatum. G. 5 boreale (Leach). Baffin’sB. 9 sericatum. D. P. Refuge. ehh ss Hollbéllii (Mangelia, Mol.) G. F. = Dalei. R. B. Pipurctoria, 13sp. G. *Fusus antiquus. N. Zemla. B. ** ,, carinatus. G. * 4, contrarius. R. O. », Geformis. R. Spitz. ** ., despectus. G. Spitz. »» heros. C, Perry. » latericeus. G. #* ,, Sabini. D. Mass. » pellucidus. D. » Kroyeri. G. Spitz. » Gdecemcostatus. B. Newf. * ,, Berniciensis. R. B. » Spitzbergensis. Spitz. * ,, Islandicus. F. * gracilis. F. R. G. B. #*'Trophon clathratus. R. G. B. EK OE ed > Gunner. F. G. » craticulatus. R. I. G. * » Barvicensis. F. » harpularius. F. U.S. oe 5 truncatus. *Purpura lapillus. R. G. B. Mangelia, 9 sp. G. i decussata. D. *Bela turricula. F. G. ( DR aiticig it ane Cre **Mitra Groenlandica. G. **Admete viridula. R. Spitz. G. 8. » scalariformis. Spitz. Newt. B. THE MOLLUSCA. + *Trichotropis borealis. F. G. B. Prince Regent Inlet. 43 conica. G. 5 insignis. B. 55 bicarinata. B. *Natica helicoides. R. G. B. ** ,, clausa, F. N. Zemla. G. Mele ville Id. P. Regent Inlet. B. » pallida. R. O. » flava. N. Zemla. B. Newf. * 4, pusilla (groenlandica). G. Norway. Spitz. >» nana. G. *Velutina levigata. RB. * , flexilis. F. ** , # ##=\wzonata. R. G. » lanigera. G. Lamellaria prodita. F. 6 Greenlandica. G. B. **Scalaria Groenlandica. F. G. B&B. ** ,, borealis (Eschrichti), G. Amaura candida. G. Chemnitzia albula. G. **Mesalia lactea. G. **Turritella polaris. G. Aporrhais occidentalis. *Littorina obtusata. R. auaaert tenebrosa. N.Zemla. D., 4 Grenlandica. G. F. by palliata (arctica). G. MS limata. F. *Lacuna vincta. R. Newf. G. » labiosa. F. BP. Refuge. Labrador. = crassior. R. » @ilacialis. G. * 4, #«jpallidula. G. * ,, puteolus. EF. Newf. Ay 9 Reet TaKTEN. 18 » Ssolidula. F. Hydrobia castanea. R. G. Rissoa scrobiculata. G. » @globulus. G. » saxatilis. G. *Skenea planorbis. G. F. **Margarita cinerea. F. U.S. Foe undulata. R. G,. * 5 alabastrum. F. * 5 helicina. G. White Sea. Spitz. x sordida. R. Spitz. G. B. 35 umbilicalis. D, B. oe Harrisoni. D. a glauca. G. ¥9 Vahlii. G. * an costulata. G, *Puncturella Noachina. F. G. *Acmea testudinalis. R. Iceland. G. ARCTIC SHELL-FISH. **Lepeta ceca. G. F. Spitz. C. Eden. Pilidium rubellum, F. G. D. Patella, 4 sp. G. *Chiton ruber. F. G. Spitz. Peo albus: bs Ge Dentalium entale. Spitz. _ Bulla Reinhardi. G. » subangulata. G. *Cylichna alba. G. F. Spitz. = turrita. G. *Philine scabra. Norway. G. ns punctata (Moll.) G. Doris liturata. G. acutiuscula. G. » obvelata. G. *Dendronotus arborescens. F. G. Kolis bodocensis. G. Tergipesrupium. G. Euplocaraus Holbollii. G. 99 *Terebratulina caput-serpentis. Spitz. F. Mass. Medit. *Waldheimia cranium. F. on septigera. F. Terebratella Spitzbergensis. Sp. a Labradorensis. Labr. **Rhynchonella psittacea, R. Baffin’s Bay, 76° N. Melville, I. B. *Crania anomala. Spitz. *Anomia squamula. R. * » aculeata. R. **Pecten Islandicus. F. N. Zemla. Spitz. G. B. St. Lawrence. vitreus. F. Arctic America. » Groenlandicus. R. Spitz. D. Limatula sulcata. G. F. *Mytilus edulis. R. G. B. *Modiola modiolus. R. B. *Crenella discors (levigata). G. D. N. Zemla. rh} * » decussata. R. G. * 4, nigra. N. Zemla, R. G. D. sll » faba. G. vitrea. G. 39 Arca glacialis. P. Regent Inlet. Nucula corticata. G. » inflata. G. D. Leda buccata. G. macilenta. G. Tostrata (pernula). F. Spitz. Arctic America. ” Bk 0 59 **TLeda 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.& 8.) Icy Cape. » limatula. F. U.S. Kamt. “0 hyperborea. Spitz. ** ,, thracieformis (angularis). @G. Mass. RE 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. * 4, elliptica. F. G. Spitz. * , sulcata. R. N. Zemla. O. ** ., crebricosta. F. Spitz. Newf. » crenata. P. Regent Inlet. » Warhami. Davis Str. » globosa. G. « compressa. N. Zemla. G. », Banksii. Spitz. Baffin’s Bay. *Cardium edule var. rusticum. R, Islandicum. N. Zemla. G. Groenlandicum. Kara. Spitz, C. Parry. St. Lawrence, ~ 4 elegantulum. G. *Cryptodon flexuosus. G. F. *Turtonia minuta. G. F. *Cyprina Islandica. R. Labrador. ** Cardita borealis. Mass. O. **Tellina calcarea. F. G. B. 99 “dod RSop ** 4, Groenlandica, (= 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. 99 **Saxicava rugosa (arctica). N. Zemla. Spitz. G. C. Parry. B. (Panopzea) Norvegica. White Sea. O. Machera costata. Labrador. O. Glycimeris siliqua. C. Parry. Newt. *Lyonsia Norvegica. F. O er) arenosa. G. D. P. Refuge. «**Thracia myopsis. G. Pandora glacialis. Spitz. Baff. (Leach). * 399 60 MANUAL OF THE MOLLUSCA.. II. BorREAL 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.¢ 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. * (Panopeea) 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. * 4, caudata. ? Lepton nitidum (fabagella, Conr. ?) ? ,, navicularis (lucida, Lovén ?) *Saxicava rugosa (arctica). *Nucula tenuis. Tellina solidula, var. (fusca, Say). *Mytilus edulis. * 4, calcarea (sordida, Couth). *Modiola modiolus. * Index Molluscorum Scandinavie; extracted from the “ Ofversigt ‘af K. Vet. 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. ft 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 degrees of longitude in the Atlantic: but the existence of 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. 61 *Crenella nigra. *Margarita undulata, ‘ , = .. .. discors, 1. * i alabastrum (= occidentalis ?) * ., decussata (glandula, Tot.) Littorina greenlandica. Pecten Islandicus. * », tenebrosa (vestita). ? Ostrea edulis (borealis, Lam. ?) » palliata? * Anomia, ephippium. *Lacuna vincta (divaricata). * 5 aculeata. * ,, puteolus (Montagui), » squamula? *Skenea planorbis. *Velutina levigata. *Terebratulina caput-serpentis. An zonata. *Rhynchonella psittacea, *TLamellaria perspicua. *Natica helicoides. *Dendronotus arborescens. op clausa. Polycera Lessonii ? * ,, pusilla. ? Amphisphyra hyalina (debilis ?) *Scalaria grenlandica. Cylichna alba (triticea, C.) (Janthina communis). >» obtusa (pertenuis). Odostomia producta. mv *Philine quadrata (formosa, St.) Cancellaria (admete) viridula, *Trichotropis borealis. *Chiton cinereus. *Fusus antiquus (tornatus). *® 4, marmoreus. * 4, island.cus. Messe eCUDEL: * ,, propinquus. * ,, levis. » Prosaceus. * ,, asellus. *Trophon muricatus. * ~,,° albus. * ,, clathratus. *Dentalium (entale, L, ?) » scalariformis. P Lepeta czeca (candida, C.) »» harpularius. *Acmea testudinalis (amoena, S.) *Purpura lapillus. *Puncturella Noachina. *Buccinum. undatum. * Adeorbis divisus (= Skeneaserpuloides). | * —_» (Cominella) Dalei. Margarita cinerea. *Bela turricula. * » costulata ? (Skenea). * ,, Trevelyana, * 5 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. T’rophon cinereus, Say., is believed to be the Fusus Forbesi, Strickland, of the Isle of Man; others are marked in the Aretio list. Ill. CrExutic PROVINCE. The Celtic province, as described by Prof. H. 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 species 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. (forbes.) In the lists of Arctic and Boreal shells the British species are distinguished by an asterisk. According to Mr. M‘Andrew’s estimate in 1850, 406 British shell-bearing mollusca were then known, of which 217 or 53 per cent. were common to Scandinavia. 246 or 61 a $5 North of Spain. 227 or 56 55 a S. Spain and Medit. 97 or 24 i xf Canary Islands. G. Jeffreys. The Nudibranchiata alone have been more fully described in the publications of the Ray Society, by Messrs. Alder and Hancock. For the marine zoology of the coasts of Denmark the “ Zoologia Danica” of O. F. Miiller is still the most important work. 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 oiis. Fusus Berniciensis. Pecten niveus. Rissoa, sp. » Lurtoni. 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. » Opercularis, 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. » casina. Natica Montagui, >» millegranus, Donax anatinus, » Imonilifera, » tumidus, Solen ensis. » nitida. Patella vulgata. Pholas candida. Velutina levigata. » pellucida, Mactra elliptica. Turritella communis. Acmea virginea, » solida Aporrhais pes-pelecani. Chiton cinereus. Periploma pretenuis. Rissoa cingillus. Scaphander lignarius. 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 Littorine 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. Limnza 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. Rissoa labiosa. Bs littoralis. Buccinum undatum. > inconspicua, 50 tenebrosa. Fusus antiquus. » ulve. Lacuna vincta. » ventrosa. » pallidula. IV. LUSITANIAN PROVINCE. 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 Mesalia, 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. — 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. — Ervilia. Ranella. Siphonaria. Megerlia, Panopzea. 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 * Tn the northern part of the Lusitanian province are the Pilchard fisheries; in the Mediterranean, the Tunny, Coral, and Sponge fisheries. The Gulf-weed banks (represented in the map) extend from 19° to 479 in the middle of the North Atlantic, covering a space almost seven times greater than the area of France. Columbus, who first met with the sargasso about one hundred miles west of the Azores, was apprehensive that his ships would run upon a shoal. (Hum- boldt.) The banks are supposed by Professor E. Forbes to indicate an ancient coast- line of the Lusitanian land-province, on which the weed originated. Dr. Harvey states that species of Sargassum abound along the shores of tropical countries, but none exactly correspond with the Gulf-weed (S. bacciferum). It never produces fructifica- tion—the “berries” being air-vesicles, not fruit—but yet continues to grow and flourish in its present situation, being propagated by breakage. It may be an abnormal condition of S. vulgare, similar to the varieties of Fucus 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, Inir. 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. >», Prometheus. Cerithium nodulosum. Cymba Neptuni. » Guinaicus. Murox saxatilis. FA 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. — 4 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 Mes 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 ........s..e.00 1 Nucleobranchiata... 6 | Lamellibranchiata ...... 200 PteropOda ..rreccossereesree 13 Gasteropoda ......... 370 Brachiopoda ........see0ree 10 On the coast of Sicily, M. Philippi has found altogether 619 marine mollusca, viz. :— IBIVAIVES! cescccscccveccscseoss 188 Pteropoda ..creccecree 13 Gasteropoda...... eabigswowes 319 Brachiopoda ......cccccceee 10 Nudibranchs ......... 54 Cephalopoda........cseeere: 15 Of the 522 which are provided with shells, 162 have not been found fossil, and are presumed to be of post-tertiary origin, so far as concerns their presence in the Mediterranean. The re- maining 360 occur fossil in the newer tertiary strata, along with nearly 200 others which are either extinct or not known living on those coasts ; a few of them are living in the warmer regions of Senegal, the Red Sea, and the West Indies :— Senegal. Antilles. Fed Sea. Lucina columbella. Lucina pennsylvanica. Argonauta hians. Cardium hians. Vermetus intortus. Dentalium elephantinum, Terebra fusca. Terebra duplicata. Morocco. Phorus agglutinans. Trochus strigosus. Niso terebellum, Pecten medius. Diplodonta apicalis. Most of them, however, are of northern origin, such as :— Saxicava rugosa Tellina crassa. Rhbynchonella psittacea. (Panopeea) Norvegica. Cyprina Islandica. Patella vulgata. Mya truncata, Leda pygmea. Eulimella Scille. Periploma prztenuis. Limopsis pygmza. Buccinum undatum, Lutraria solenoides. Ostrea edulis. Fusus contrarius. Of the 522 Sicilian testacea, about 35 (including 10 oceanic species) are common to the West Indies—if the species haye been correctly determined ; 28 are stated, with more probability, to be common to West Africa, including Murex Brandaris and other common species; 74, including Murex trunculus, are com- mon to the Red Sea; Crania ringens cannot be distinguished from the species found in New South Wales (Davidson); and Columbella corniculum ranges from the north coast of Spain to Australia, the specimens from these distant localities being only distinguishable as geographical varieties. (Gaskoin.) Six other species are included in Menke’s Australian Catalogue, but res quire verification. The following genera, nine of which are naked molluscs, are LUSITANIAN PROVINCE. 67 supposed to benow peculiar to the Mediterranean ; the small number of species show they are aberrant or expiring forms. Cassidaria, and Thecidiwm are ancient, widely-distributed genera, and the Mediterranean Thecidiwm occurs fossil in Britiany and the Canaries. Thysanoteuthis, 2 sp. Sczeurgus, 1. Morrisia, 2. Verania, 1. Pleurobranchea, 1. Thecidium, 1. Dosidicus, 1. Tethys, 1. Scacchia, 2. Doridium, 1. Cassidaria, 6 : Icarus, 1. Pedicularia, 1. The genera Fasciolaria, Siliquaria, Tylodina, Notarchus, Verti- cordia 2 Clavagella, and Crania, occur only in this portion of the Lusitanian province. Amongst the peculiar species are :— Nassa semistriata. Argiope cuneata. Artemis lupinus. Fusus crispus. Clavigella angulata. Trigona nitidula. Tylodina Rafinesquii. Spondylus Gussonii, Lucinopsis decussata. Crania rostrata. Astarte bipartita. Agean Sea. Prof. H. Forbes obtained 450 species of mollusca in the Aigean, belonging to the following orders :— Cephalopoda ...........++6 4 Nudibranchs ..... woe 15 = Brachiopoda ...:.....0c000. 8 PLELOPOGA, ce. ecc<.cssenee 8 Opisthobranchs...... 28 Lamellibranchs ......... 143 Nucleobranchs ............ Uf Prosobranchs ......... 217 UNICALAersareeedssoreetes 22 Of these 71 were new species, but several have since been found in the Atlantic, and even in Scotland.* Theonly marine air-breather met with was Auricula myosotis. Black Sea. In the northern part a few Aralo-Caspian shells are found, otherwise the Black Sea only differs from the Medi- terranean in the paucity of its species; Dr. Middendorff enume- rates 68 only. The water is less salt, and there is no tide, but a current flows constantly through the Dardanelles to the Mediterranean.t+ Lorenz{ found 178 molluscs at Quarnero, of which 75 were bivalves, and 88 univalves; 75 of them extended their range into the Aigean Sea, 58 into the Boreal province. Few only appeared to be peculiar to the Adriatic. * Trans. Brit. Assoc. (for 1243), 1844, p. 130. 7 A current from the Atlantic sets in perpetually through the Straits of Gibraltar, and there is scarcely any tide ; it only amounts to one-foot at Naples and the Euripus, two feet at Messina, and five at Venice and the Bay of Tunis. ¢ Physikalische Verhaltnisse und Vertheilung der Organismen im Quarnerischen Golfe. Wien, 1863. 65 MANUAL OF THE MOLLUSCA. V. ARALO-CASPIAN PROVINCE. The only inland salt-seas that contain peculiar shell-fish are the Araland Caspian. ‘The shells chiefly consist of a remarkable group of Cockles which burrow in the mud (see fig. 213, p.402). No explorations have been made with the dredge, but other species, probably still existing in these seas, have been found in the beds of horizontal limestone which form their banks and extend in all directions far over the steppes. This limestone is of brackish water origin, being sometimes composed of myriads of Cyclades, or the shells of Dreissena and Cardiwm, as in the islets near Astrakhan. It is believed to indicate the former existence of a great inland sea, of which the Aral and Caspian are remnants, but which was larger than the present Mediter- ranean at an age previous to that of the Mammoth and Siberian Rhinoceros. The present level of the Caspian is 83 feet below that of the Black Sea; that of the Aral has been stated to be 117 feet higher than the Caspian, but is probably not very different; their waters are only brackish, and in some parts drinkable. The steppe limestone rises to a level of 200—300 feet above the Caspian; it spreads eastward to the mountains of the Hindoo Kush and Chinese Tartary, southward over Daghestan and the low region E. of Tiflis, and westward to the northern shores of the Black Sea. The extent to which it has been traced is represented by oblique lines on the map.* Some of the Caspian shells still exist in the Sea of Azof and the estuaries of the Dnieper and Dniester. Our information upon this seldom-visited region is derived from the works of Pallas, Eichwald,+ Krynicki,{ Middendorff, and Sir Roderick Mur- chison. Aralo-Caspian Shells. A, Aral; C, Caspian ; B, Black Sea. The Species marked * are found also in the Steppe limestone. *Cardium edule, L. C. (very small) B. Baltic. » edule, var. (rusticum, Chemn.) A. C. B. Icy Sea. *Didacna trigonoides, Pal. C. (Azof. M. Hommaire). » Hichwaldi, Kryn. (crassa, Eich.) C.B. (Nikolaieff). Monodacna Caspia, Eich. C. 5, pseudo-cardium, Desh. (pontica, Eich.) B. Adacna leviuscula, Eich. C,. vitrea, Eich. C. A. 99 * From a sketch kindly prepared by Professor Ramsay. + Geogr. des Kaspischen Meeres, des Kaukasus und des Siidlichen Russlands. Berlin, 1630. Fauna Caspio-Caucasica, 1841. ¢ Bull. des Nat. Moscow, 1837, WEST AFRICAN PROVINCE. 69 *Adacna edentula, Pallas. C. , plicata, Eich. C. B. (Dniester, Akerman, Odessa). » colorata, Eich. C. B. (Azof, Dnieper). *Mytilus edulis, L. C. C. (not in Middendorff’s list). >» latus,Chemn. B. *Dreissena polymorpha, Pal. ©. B Paludinella stagnalis, L. (pusilla Eich.) C. B. (Odessa) Ochotsk. * 4, variabilis, Eich. C. *Neritina liturata, Eich. C. on sea-weed. *Rissoa Caspia, Eich. C. » Oblonga, Desm. B. » ¢ylindracea, Kryn. B.* The following species are described by Eichwald, from the steppe limestone. (Murchison, Russia, p. 297.) Donax priscus. ‘6 Paludina ” Triton. 55 exigua. Mactra Caspia. Monodacna propinqua. Ri: soa conus. » Karagana. a intermedia. >, dimidiatus. Cyclas Ustuertensis. 3 Catillus. Bullina Ustuertensis. Mytilus rostriformis. Adacna prostrata. No other inland bodies of salt water are known to have 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.+ VI. West 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 tu be done. Dr. Dunker has described 149 Ges 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 ZL. 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. J A species of coral (Porites elongata, Lam.), now living at the Seychelles, has been said to be found in the Dead Sea (v. Humboldt’s Views of Nature, Bohn ed. p. 260); also Melania costata and M. Jordanica, according to M. Schubert. ¢ 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 Jetters he could invent. § Appendix to Captain Tuckey’s Narrative (1818), by Dr. Leach. — a 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 vitulinus. » angularis. > megaceros. > rosarius. » duplex. >, cornutus. Clavella? filosa. on GUBINS Lagena nassa. Terebra striatula. $5 ferruginea. ? Halia priamus. Mitra nigra. Cymba. MANUAL OF THE MOLLUSCA. West’ African Shells. Marginella. Persicula. Pleurotoma mitriformis. Tomella lineata. Clavatula mitra. BS coronata. 2p bimarginata. 35 virginea. Conus papilionaceus. » genuinus. ,, testudinarius. ,, achatinus. 5, monachus. Natica fulmines. Cypreea stercoraria. 5 picta. Vermetus lumbricalis. Cerithium Adansonii. Turritella torulosa. Mesalia. Littorina punctata. Collonia. Clanculus villanus. Haliotis virginea. Ss coccinea. Nerita Senegalensis. 55 Ascensionis. Pecten - bbus. Arca vn © COSa. » senilis. Cardium ringens. 25 costatum. Lucina columbel'a. Ungulina rubra. Diplodonta rosea. _Cardita ajar. Artemis africana. > torrida. Cyclina Adansonii. Trigcna bicolor. a tiplals Cytherea tumens. a africana. Venus plicata. Tellina. Strigilla Senegalensis. Gastrana polygona. Mactra depressa. » rugosa, mistake, 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. 71 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. Macira spengleri. Gastrana ventricosa. Nucula pulchra, Hinds. (L’Agullias bank, 70 fm.) Pectunculus Belcheri, 120 fm. Modiola Capensis. » pelagica, Forbes. Septifer Kraussi. Terebratulina abyssicola, 132 fm. Terebratella (Kraussia). 6 rubra. 9 cognata. By pisum. - Deshayesii, 120 fm. Chiton, 16 sp. Patella, 20 sp. »» cochlea, 9» compressa. Patella apicina. », longicosta, » pectinata, &c, Siphonaria, 5 sp. Pupillia (aperta). Fissurella, 10 sp. Crepidula, 4 sp. Haliotis sanguinea. Delphinula granulosa. ap 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. op lagenaria. op limbosa. Cominella tigrina. Bullia leevissima, » achatina. » natalensis. Nassa plicosa. + capensis. Cyclonassa Kraussi. Eburna papillaris. Columbella, 5 sp. Ancillaria obtusa. Mitra, 5 sp. Imbricaria carbonacea. Voluta armata. » Scapha. », abyssicola, 182 fm. Marginella rosea. Trivia ovulata. Cypreea, 22 sp. Luponia algoénsis. Cyprovulum (capense). Conus, 8 sp. Octopus argus. Sepia, 4 sp. The following are stated to be common to the Cape and Huro- pean seas.t Saxicava (arctica?) Greenland, Medit. Tellina fabula, Brit. Medit. Chama gryphoides, Medit. Red Sea. Pecten pusio, Brit. Lucina lactea, Medit. Red Sea. » fragilis, Medit. Canaries, Red Sea, Australia ? Tapes pullastra, North Sea. » geographica, Medit. Arca lactea, Medit. 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. VIII. Inpo-PactFic 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. 7 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. This great region might, indeed, be subdivided into a number of smaller provinces, each having a particular association of species and some peculiar shells, such as the 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-Facific, those marked (*) are wholly wanting on the coasts of the At- lantic, but half of them occur fossil in the older tertiaries of Europe. Those in italics are also found on the west coast of America. *Nautilus. 4Magilus. 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. *Meroe. *Turbinella (typ.) Siliquaria. *Placuna. Anatinella. Cyllene. *Quoyia. *Malleus. Cultellus. Eburna. *Tectaria. *Vulsella. *Anatina. Phos. Imperator. *Pedum. *Chena. Dolium. Monodonta. * Septifer. *Aspergillum. Harpa. Delphinula. *Cucullea, *Jouannetia. *Ancillaria. Liotia. *Hippopus. *Lingula. &Ricinuia. *Stomatia. *Tridacna. Discina. The strictly littoral species vary on each ereat line of coast : for example, Littorina intermedia and Tectaria pagodus occur on * See Mrs. Somerville’s Physical Geography, il. 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.; Pieurotoma, 100; Mitra, 250; Golumbella, 40; Cyprea, 50; Natica, 50; Chiton, 30; Zellina, 50. 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 ZL. picta, at the Sandwich Islands. Red Sea (Krythreean). 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 shelis. 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. Oliva. Nerita. Perna. Aspergillum. Other genera become abundant, suchas Oonus, of which there are 19 species in the Red Sea, Cypreea 16, Mitra 10, Cerithium 17, Pinna 10, Chama 5, Circe 10. Persian Gulf. The marine zoology of the Persian Gulf and adjoining coast has not been yet explored.* The following shells were picked up on the beach at Kurrachee by Major Baker, with many others evidently new, but not in a satisfactory state for descrip- tion. (1850.) Rostellaria-curta. Purpura persica. Sigaretus sp. Murex tentispina var. » carinifera. Odostomia sp. Pisania spiralis. Columbella blanda. Phorus corrugatus. Ranella tuberculata. Oliva subulata. Planaxis sulcata. » Spinosa. » Indusica. Imperator Sauliz. a crumena. >» ancillaroides. Monodonta sp. Triton lampas. ; Cyprea Lamarckii. Haliotis sp. Bullia sp. an ocellata. Stomatella imbricata. Eburna spirata. Natica pellis-tigrina. 6 sulcifera. .* The “Brindled Cowry” (Cyprea princeps), from the Persian Gulf, was valued at £50. : _&& 74 MANUAL OF THE MOLLUSCA. Fissurolla Ruppellii. a Indusica. on salebrosa. p dactylosa. % funiculata. Pileopsis tricarinatus. Nerita ustulata. Dentalium octangulatum. Ringicula sp. Bulla ampulla. Anomia acheus. 5 enigmatica. Pecten sp. Spondylus sp. Plicatula depressa. Mytilus canaliculatus. Arca obliquata. 5 sculptilis, &c. Chama sp. Lucina sp. Cardium fimbriatum, y latum. Cardium impolitum. 1) pallidum. 55 assimile. Venns pinguis. 99 COL. >, purpurata. Meroé Solandri. » effossa. Trigona trigonella ? Artemis angulosa. op exasperata, 55 subrosea? Venerupis sp. Petricola sp. Tapes sulcosa. » Malabarica. Cypricardia vellicata. Cardita crassicostata? | », calyculata. » Lankervillii. Mactra Agyptica, &c. Tellina angulata. Tellina capsoides. ; Mesodesma Horsfieldii, Psammobia sp. Syndosmya sp. Semele sp. Solen sp. Solecurtus politus. Donax scortum. » scalpellum. Sanguinolaria diphos. o violacea. a sinuata. Corbula sp. Diplodonta sp. Anatina rostrata. Pandora sp. Martesia sp. Pholas australis. 5, Bakeri, Desh. 5 orientalis. (Meleagrina v. p.416). At the Cargados or St. Brandon shoals, north of Mauritius, Voluta costata, Conus verrucosus, Pleurotoma virgo, and T'urbinella 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., Dolium galea and Cypreea heivela, and two of the bivalves, are found in the Mediterranean. 1X. 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.t{ Of the following genera some are peculiar (*), others attain here their greatest development :— * Travels in New Zealand, by Dr. E. Dieffenbach. 8vo., London, 184%. + Moll. Nov. Hollandiz, 1843. t 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 :— Solenella—Chili. Bankivia—Cape. Rhynchonella—Arctic seas. Panopzea—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, &c. . Venus Stutchburyt and Modiolarca trapezina have been found at Kerguelen’s Id. and Patella illuminata at the Auckland Ids. X. JAPONIC PROVINCE. The Japanese Islands and Corea represent tha Japonic pro- vince. Our knowledge of its molluscan fauna ie still scanty, notwithstanding the successful researches of Mr. Adams. Up- wards of 130 species were collected in the harbour of Decima, by Dr. Nuhn, of which 113 were Prosobranchiates. Octopus areolatus. Sepia chrysopthalma. Sepioia Japonica. Conus Sieboldi. Pleurotoma Coreanica. Terebra serotina, " stylata. Eburna Japonica. Cassis Japonica. Murex eurypterus. » rorifluus. Ay plorator. a Burneti. Purpura, 5 sp. Fusus. Cancellaria nodulifera. Mitra. Strombus corrugatus, _ Cypreea fimbriata. by miliaris, Mangelia, 4 sp. Triforis, 5 sp. Natica, 5 sp. Trochus, 15 sp. Radius birostris. Cerithium longicaudatum. Imperator Guilfordiz. E 2 Haliqtis Japonica. 3, discus. » gigantea. Bulla Coreanica. Siphonaria Coreanica. Pecten asperulatus. > . minuta: “Ss: Onychoteuthis Kamtschatica. 3 grandis. A. Fissurella violacea. S. Terebratella frontalis. O. a aspera. S. Placunomia macroschisma. O. Haliotis Kamtschatica. Pecten rubidus. S. aa aquatilis. K. Crenella vernicosa. O. Velutina coriacea. K. 55 cultellus. Kamt. » cryptospira. O. Nucula castrensis. S. Trichotropis inermis. S. Pectunculus septentrionalis. A. Purpura decemcostata. (Mid.) S. Cardita borealis. O. o> Freycineti. O.S. Cardium Nuttalli. S. 33 septentrionalis. S. ~ Californicum, S. Pleurotoma Schantarica. Saxidomus Petiti. S. 53 simplex. O. 5 giganteus. S. Murex monodon. S. Petricola cylindracea. S. 5 Jactuca. S- = gibba. S. Fusus (Chrysodomus) Sitchensis. Tellina lutea. A. nasuta. S. r decemcostatus. A. >» edentula. A. 99 Schantaricus. Lutraria maxima. S. 39 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 Fisswrella, 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. 67 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 Hixploring 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.” ven this single identification has since been doubted. Mr. Cuming, who resided many years at Valparaiso, did not discover any West India specimens on that coast, and M. D’Orbigny makes the same observation. On the other hand M. Morch, of Copenhagen, says he has received Tellina opercu- lata and Mactra alata from the west coast and also from Brazil ; and M. Deshayes gives the following extraordinary ranges in his ‘‘ Catalogue of Veneride in the British Museum ”’:— Artemis angulosa, Philippines—Chili. Cytherea umbonella, Red Sea—Brazil. Br maculata, W. Indies—Philippines, Sandwich. on 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 Lessonti, nearly smooth, Atlantic coast; S. antarctica, ribbed, Pacific coast; aud 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 1t is true that any number of living species are common to the Pacific and Atlantic shores, it becomes probable that some portion of the Isthmus of Darien has been submerged since the Eocene Ter- tiary period. Any opening in this barrier would allow the Equatorial current to pass through into the Pacific—there would be no more Gulf stream—and the climate of Britain might, from this cause alone, become lke 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 in the British seas. XII. CALIFORNIAN PROVINCE. The shells of Oregon and California have been collected and described by Mr. Hinds,+ Mr. Nuttall,f 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. Tyochus ater. Trochus euryomphalus. me aspera. » meestus. Petricola cylindracea. Fissurella violacea. » okkesii. Lutraria maxima, 3 aspera. * Voyage dans |’ Amérique Mérdionale. 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. S. Philadelphia, 1834. § Gould in Bost. Nat. Hist, Soc. Proceedings, 1846; and U.S. Exploring Exped. (Commander Wilkes), vol. xii, Mollusca, with Atlas. 4to. Philad. 1852. || Explorations for a railroad route from the Mississippi to the Pacific Ocean. 1856. j P. P. Carpenter on Mollysca 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; Acmeea, 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. $ punctatus. Waldheimia Californica. Mactra, 2. Donax, 1. Cancellaria urceolata. Discina Evausii. Tellina Bodegensis. Trivia Californica. — » secta, &c. Natica herculea. Anomia pernoides. Semele decisa. 9 Lewisii. Placunomia cepa. Cumingia Californica. Calyptreea fastigiata. Hinnites giganteus. Sanguinolaria Nuttalli. Crepidula exuviata. Perna, 1. Pinna, 2. Lutraria Nuttalli. Ae navicelloides. Mytilus, 1. Pecten, 2. Platyodon cancellatus. “ solida, &c. Mytilimeria Nuttalli. Amphichena Kindermanni. Imperator Buschii. Modiola eapax. Lyonsia, 1. Thracia, 1. Haliotis Cracherodii. Chama lobata. Pandora, 1. Saxicava, 2. » fulgens. Cardita ventricosa. Cyathodonta undulata. » corrugata. Cardium, 4. Sphenia Californica. Fissurella crenulata. Lucina, 3. Periploma argentaria. os cucullata. Chironia Laperousii. Solecurtus subteres. Puncturella, 2 sp. Solecardia eburnea. Machaera lucida. Dentalium politum. Venus Californiensis. 35 maxima. Patella, 15 sp. >» callosa. Mya truncata. Acmeea scabra. Artemis ponderosa. Panopea generosa. 3 pintadina. Saxidomus Petiti. Pholas Californica. Chiton Mertensii. of Nuttalli. » 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- vinces. 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 Chitonide, 13 Acmeide, 18 Fissurellide, 64 Trochoide, 28 Calyptreidee, 69 Pyramidellide, 59 Buccinidee, 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 S. 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, vyiz., 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 Littorince climb the trees and are found upon their leaves. The ordinary tide at Panama amounts to 16 or 20 feet, the extreme to 28 feet, so that once a fortnight a lower zone of beach may be examined and other shells collected. soe beach is of fine sand, with reefs of rocks in the bay. Gallapagos Teh —Out of 111 sea-shells collected here by Mr. Cuming, 43 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. } Cypreea 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. x bicanalifera. po MUX. Sipkonaria gigas. > hemastoma. Strombus granulatus. Strembus gracilior. Murex erythrostomus. » regius. » imperialis. Dome Racloxe » brassica. » Mmonoceros, &c. Rapana muricata. » Kiosquiformis, Myristica patula. Ricinula clathrata. Purpura, many sp. Monoceros, many sp. os brevidentattis. % cingulatus. Clayella? distorta. Qliva porphyria. » splendidula, &c. Northia pristis. Harpa crenata. .Malea ringeng. Mitra Inca, &c. Terebra luctuosa, &c. Conus regularis, &c. Pleurotoma, many sp. Cancellaria goniostema. 5 cassidiformis. oA chrysostoma, Columbella, many sp. PERUVIAN PROVINCE. 81 Panama shells. Columbella strombiformis. Marginella curta. Cypreea nigro-punctata. Pecten magenificus. Arca lithodomus, &c. Pectunculus tessellatus, &¢. Trivia. Nucula exigua. Pyrula ventricosa. Leda, 5 sp. Natica glatca. Cardium senticosum. Pileopsis hungaricoides. >» maculosum. Crucibulum auriculatum, &c. Cardita laticosta. Trochita mamillaris. Gouldia Pacifica. Crepidula arcuata, &c. Cytherea, mary sp. Littoring, pulchra. Venus gnidia, Turritella Californica. » histrionica. Truncatella, 2 sp. Artemis Dunkeri. Ceecum, § sp. Trigona crassatelloides. Imperator unguis, &c. Cyclina subquadrata. Trochus pellis serpentis. Venerupis foliacea, Vitrinella, 12 sp. Petricola Californica, &c. Nerita ornata. Tellina Burneti. Patella maxima. Cumingia coarctata. Semele, 7 sp. Saxicava purpurascens, Gastrocheena. Solecurtus lucidus. Lyonsia brevifrons. Pandora arcuata, &c. Pholas melanura, &c. Parapholas. Jouannetia pectinata. Discitia strigata. 59 Cumingii. Lingula semen. » albida. » audebardi. Placunomia foliacea, Ostrea eequatorialis. Spondylus princeps. XIV. Peruvian Province. The coast of Peru and Chili, from Callao to Valparaiso, affords — a large and characteristic assemblage of shells, of which only.a small part have been catalogued, although the district has been well explored, especially by D’Orbigny, Cuming, and Philipp. M. D’Orbigny collected 160 species, one-half of which are common to Peru and Chili, whilst only one species (Siphonaria Lessonit) 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. Onychoteuthis-peraptoptera. AMolis Inca. Doris Peruviana. Chiton, many sp. Patella scurra. Acmeza scutum, Crucibulum lignarium, Diphyllidia Cuvieri. Posterobranchea. Aplysia Inca. Tornatella venusta. E93 82 MANUAL OF THE MOLLUSCA, Trochita radians, Oliva Peruviana. Solen gladiolts. Crepidula dilatata. Rapana labiosa. Solecurtus Dombeyi. Fisstirella, many sp, Mouoceros giganteus, Mactra Byronensis. Liotia Cobijensis. :; crassilabris. Mesodesma Chilensis. Gadinia Peruviana, r acuminatus. Cumingia lamellosa. Littorina Peruviana. Purpura chocolata. Semele rosea, &c. ~ araucana, Concholepas. Petricola, many sp. Rissoina Inca, Mitra maura. Saxidomus opacus, &&. Cancellaria buccinoides, —— Cyclina Kroyeri. Sigarettis cymba. Terebratella Fontainei. Venus thaca. Fusus Fontainei. a 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. 5) Donovani? “5 glabratus. Voluta Magellanica. Bullia cochlidium. 5 calcar. » ancilla. * Shell-fish are here the chief support of the natives as well as of the wild animals. At Low’s harbour a sea-otter was killed in the act of carrying to its hole 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. * 5 zebrina. Mytilus Magellanicus, Littorina caliginosa. Siphonaria lateralis. *Modiolarea trapezina, Chemnitzia Americana. Chiton setiger. Leda sulculata. *Scalaria brevis. Doris luteola. -*Cardita Thouarsii. *Trochita pileolus. ZHolis 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. *Fissureila radiosa. * ,, Magellanica,many' Pandora cistula. Puncturella conica. varieties. Saxicava antarctica. Nacella cymbularia, Waldheimia dilatata. Octopus megalocyathus. *Patella deaurata. Pecten Patagonicus. XVI. PATAGONIAN PROVINCE. From S. 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. AKolis. Leda. Columbella sertularium. Paludestrina. Cytherea. Bullia plobulosa. Scalaria. Petricola. Pleurotoma Patagonica. Natica, Corbula. Fissurellideea megatrema. Chiton, Pinna. Panopzea 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. West India Shells. Argonauta. Ommastrephes. Cleodora. Octopus. Sepioteuthis. Creseis. Philonexis, Sepia. Cuvieria. Loligo. Spirula. Atlanta. Cranchia. Hyalea. Oxyeryus. Onychoteuthis. Strombus gigas. Pr pugilis. Murex calcitrapa. Pisania articulata. » turbinella. Triton pilearis. a CULAGeUSs. Fusus morio. Fasciolaria tulipa. Lagena ocellata. Cancellaria reticulata. Fulgur aruanum. Terebra acicularis. Myristica melongena. Purpura patula. as deltoidea. Oniscia oniscus. Cassis tuberosa. > fammea. » Madagascariensis. Columbeila mercatoria. $5 nitida, &c. Voluta vespertilio. 3) MUSICA. Oliva brasiliensis. » angulata. jaspidea, » oryzae, &c. Ancillaria glabrata. Conus varius, &c. ”> Clavatula zebra. Marginella. Erato Maugerie. Cypreea mus. » exanthema. » Sspurca, &c. Trivia pediculus. Ovulum gibbosum. Natica caurena. Pyramidella dolabrata. Planaxis nucleus. Littorina zic-zac. 3 flava. Ay lineolata. Tectaria muricata. Modulus lenticularis. Fossarus. Truncatella caribbea. Torinia cylindracea. Turritella exoleta. 3 imbricata. Trochus pica. Imperator tuber. 5 calcar. Fissurella Listeri. y nodosa. + 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. 3, macrophylla. Cardium levigatum. Lucina tigrina. » Pennsylvanica. 5, Jamaicensis. Corbis fimbriata. Coralliophaga. CrassateHa. Gouldia parva. Venus paphia. » dysera. TRANS-ATLANTIC PROVINCE. 85 Venus crenulata, Artemis concentrica. Strigilla carnaria, » cancellata. pe lucinalis, Sernele reticulata. » vViolacea. Cyclina saccata. » Vvariegata, Cytherea dione. Trigona, mactroides. Cumingia. » Circinata. Petricola lapicida. Iphigenia Brasiliensis. as maculata, Capsula coccinea. Lutraria lineata, a gigantea. Tellina Braziliana, Periploma inzequivalvis. 5 flexuosa. » bimaculata. Pholadomya candida, XVIII TRANS-ATLANTIC PROVINCE. The Atlantic coast of the United States was supposed by Prof. H. 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 moreoyer 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 stragelers 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. “5 4sp. M. Nassa obsoleta. M. F. (Mex.) Triforis nigro-cinctus. M, », trivittata. M. SC. : Odostomia, 6 sp. M. Y. » Vibex. M. F. (Mexico). Turritella interrupta.. M.-Y. Purpura Floridana. (Mex.) 36 concava. SC. Terebra dislocata. Y. SC. (Vermetus lumbricalis. M. 2) Pyrula? papyracea. F. Calyptreea 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). a multistriata. M. Y. Avicula Atlantica. F. sn tusbinaallNC. ™ Mytilus leucophantus. SC. _-—————. * The sea-shells, of the United States have also been collected and described by Say, Le Sueur, Conrad, and Couthouy. 86 MANUAL OF THE MOLLUSCA. Modiola Carolinensis. Mactra similis. SC. M. as) Ditcatula, AV Ns », solidissima, M. Y. Pinna muricata. SC. » lateralis, M. Y. Arca ponderosa. SC, Lutraria lineata. F. » pexata. M.F. » canaliculata, Y. F. », incongrua., SC. Mesodesma arctata. M. Y. », transversa. M. Y. Tellina tenta. M. SC. Solemya veltm. M. Y. Pecisits “SORE » borealis. M. Semele equalis. SC. Cardium ventricosum. SC. Cumingia tellinoides. M. 55 Mortoni. M. Y. Donax fossar. Y. Lucina contracta, Y. » variabilis. G. F. Astarte Mortoni. Y. Solecurtus fragilis. M. SC. » Dilundlata. F. a caribbeus. M. F. Carditaincrassata. F. Corbula contracta. M. F. Venus mercenaria. M. SC. Periploma Leana. M. Y. 3 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. 99 pholadiformis. Y.. » semicostata. SC. LAND REGIONS. Distribution of Land and Fresh-water Shelis. 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 meridian ; aud that in passing south- ward, along the three principal lines of land, specific identities 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 ageney. Land-snails are in favour with Portuguese sailors, as “‘ live sea stock ;” and they have naturalised the common garden-snail of Europe (Helix aspersa) in Algeria, the Azores, and Brazil; and Helix lactea at Teneriffe and Mte. Video. 7.-%.-+... 1 The fresh-water shells belong to these genera and sub )genera :— MAMAN GEA... cece scien a ranavO MGW CTIA cacmssssateesesess 1 Unio, sp. and vars. ... 20 Amphipeplea ......... 2 Neritina, vars. ......... 3 Anodon, vars. ......... 20 TLV RE podtbodt enoaRmaenener 5 Paludina and Bithynia 23 Alasmodon ............ 3 ATIOR OY fecameacune'enease's 1 WWiallweitavaes saeccekis-telsscs 5 @yClasr schevacvescomure: 6 IPTAMOLDISS wencscilsastseie 16 Conovulus (Alexia)... 3 JEW GRITEEN © Séqodecobedonsc 11 PATYCVUS te vesinniceieies(desies 7 DTICSSENA . 2... .0000 IL 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 pecuhar, 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 Limnea involuta have only been met with in ‘the south-west of Ireland, but are possibly Lusitanian species. | Dreisena polymorpha has heen permanently naturalised in canals (. 424), and Testacella Maugei and haliotidea in gardens; Bu- lamus 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. as TUGEFALAS. «css .cc0tsescek Germany. », labyrinthica (Eocene) New England. Paludina marginata ......... France. Corbicula consobrina ......... Egypt and India. Wniowittoralis.s-c-eesseese ere France and Spain. On the other hand, some of the commonest living species have not been found fossil; e.g. Heliw 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 haye been made of the number of air-breathing molluscs inhabiting the various countries of Europe :— France, 202 (176 land, 26 fresh-water), Moguin Tandon. Dalmatia, 202(197 ,, 5 a5 ), Bellottz. Denmark, 95 (72 ,, 23 a ), Morch. Norway, 52(36 ,, 16 ss ), Martens and Friele. Finland, 41(23 ,, 26 3 ), Nylander and Nordenskjold. Hapland, 16 (10 —,. 46 a ), 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 Limnca 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°. 55 palustris, es 3 » hispida, Beresov. Bernaul. x9 truncatula, ,, Tomsk, », ruderata, Stanowoj Mtn. AA leucostoma, Irkutsk. 5» pura, A Physa hypnorum, Bernaul; Taimyrlance s» Ssub-personata, ,,; Ochotsk. Planorbis corneus, Bernaul; Beresov; Pupa muscorum, Bernaul. Kirgisensteppe, Altai. Zua lubrica, 35 Planorbis complanatus, Altai, Succinea putris, 3+; Irkutsk. 95 albus, Bernaul, ,, Limnza Gebleri, M. Bernaul. “5 contortus, 4, 4 auricularia, Nertschinsk. = vortex, 33 + ovata, Bernaul. + leucostoma, ,, a Kamtschatica, Mid. a nitidus, Irkutsk. + peregra, Bernaul, Beresov. Bithynia tentaculata, Bernaul. LUSITANIAN REGION. 91 _ Bithynia Kickxii, R. Ami, Altai. Anodon anatinus, Tunguska. Valvata cristata, var. Sibirica, Bernaul, a cellensis var. Beringiana, Kamt- Beresov ; Kamtschatka. schatka, 55 piscinalis, R. Ami. Cyclas calyculata, Bernaul, R. Lena, R. Unio complanatus Kamtschatka, Ami, 8S. Kamts. », Dahusicus, Mid. Schilka. Pisidium fontinale, Beresov. » Mongolicus, M. Gorbitza, Dauria. 55 obliquum, Bernaul, Tomsk. Anodon herculeus, M. Scharanai. 2. LUSITANIAN REGION. The countries bordering the Mediterranean, with Switzerland, Austria, and Hungary, the Crimea (Taurida), and Caucasus, form a great province (or rather cluster of provinces) to which Professor H. Forbes applied the term Lusitanian. The Canaries, Azores, and Madeira are outlying fragments of the same region.* In Southern Europe about 600 land-snails are found, of which above 100 are also spread over the Germanic region and Siberia; and 20 or 30 are common to Northern Africa. Besides these 60 others are found in Algeria and Egypt, 100 in Asia Minor and Syria, and 135 in the Atlantic Islands, making a ‘total of nearly 900 species of Helicidce.+ 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 Cyclostomidee and 44 Limacidee :— AELOLIX eecasahiscacsces ess « 392 Waiting) oe. chsenecccees 11 @ryptellasetneeetecssse 1 BS UNTINIUS eeneaeeeesy -lesee= 80 Daudebardia............ 3 Cyclostoma ............ 5 DUGCIM EG Aimee nt encevecs 8 Helicolimax ............ 3 Craspedopoma ......... 3 Achatina ............... 25 PBiMAK ae castdsecaeee: 28 Pomatias .............. 10 Tornatellina ............ 3 ATION (eone Citeriecaeceee- ee 7 PN GIG), cchoacanccosabccce 4 MB ACA a sissnce secs saelsses 4 Phosphorax ............ 1 ae IPDS cncescmasccsccsetar ss 120 Mestacellaleeeacerctses 2 Carychium ....... gecce: | 8 Clausiliang it shies.-scce 247 Parmacella (2s......-+. 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 549°—72°. 7 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, but only as races, or geographical varieties. 92 MANUAL OF THE MOLZUSOA. 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 Huphrates, 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 localities, Switzerland has 28, the Austrian Alps 46, Carpa- thians 28, North Italy and Dalmatia 100, Roumelia 20, Greeee and its Archipelago 90, Anatolia 50, Caucasia 20, Syria 30, Lower Egypt and Algeria 60, Spain 26, and Portugal 15 Helicide and 9 Limacide. Mediterranean Islands. Corfu, Cyprus, Rhodes, Syra, Candia, and Crete, have each a few peculiar land-snails, amounting to 40 species altogether. Balearic Isles.—Helix Graellsiana, hispanica (var. balerica), nyellii, minoricensis ; and Cyclostoma ferrugineum, common to Spain and Algeria. Corsica.—Helix Raspaili, tristis, Clausilia 4 sp. Sardinia.—Hehx Sardiensis, meda, tenui-costata, Pupa 2, Clausilia 1. Malta has 2 peculiar species of Helix, and a Clausilia (scalaris). Sicila ly has 40 peculiar species of Helices and 3 Limaces. This island is connected with North Africa by a winding shoal with deep water on each side. Madeira Group. These ancient volcanic islands, 660 miles south-west of Por-- tugal, consist of Madeira, with Fora and three other islets called Dezertas, and Porto Santo, 26 miles to the north-east, with the rocky islets Ferro, Baxo, and Cima.* The land-snails have been described by the Rey. R. T. Lowe,}+ and form the sub- ject of a monograph by Dr. Albers.{ The investigations of Mr. Vernon Wollaston have nearly doubled the number of known species, which now amount to 134. The Vitrine belong * These islands, and also the Canaries and Azores, contain marine formations (volcanic grits and tufas) with Miocene Tertiary shells. The islet of Baxo is quarried for lime. } Primitiz et novitize Faune et Flore Madere et Portus Sancti. 12mo. Lond., 1851+ Descriptive list of all the species, by same author, Zool. Proc. for 1854, p. 161. The statements and numbers given above are taken from this last monograph, corrected by 2d, Wollaston. { Malacographia Maderensis, 4to. Berlin, 1854, with figures of all the specics. LUSITANIAN REGION. 93 to the section Helico-limax, the Cyclostomas to the sub-genus Craspedopoma, and half the Pupas to Vertigo. FATION ...--s000cstees SWIMS) Ceres. se 2 Cionella ..... spon) LagbaahTES), asec 1 PTIMNAXS Fie ssceses 4 Glandina......... WONT EAR Oe once teste ers Zo PAM GY IISieenesee sane aKk Testacella ......... OF VAWEC Ay Sto. ea ss Sul alee eens ¥ ‘@onovalus 4-2--.-- 3 SUATTING, |. cccetsce-<: 8 Tornatellina ..... NOC laste weeer esse 3 Pedipes (afra.)... 1 VGTING Gs vesevesss MOMAZUA ce secesccesoe 2 Cyclostoma...... 2 Of the 92 found in Madeira or the Dezertas, 70 are peculiar ; 54, of which 39 are peculiar, inhabit Porto Santo and its islets; 11 others, of which 4 are widely diffused, are common to,Madeira and Porto Santo. One species is peculiar to the Dezerta Grande; 1 species and 1 variety to the southern Dezerta (Bugio); 1 to the northern (Cho); 1 variety to Ferro. Seven species are common to the Dezertas; 1 to the great and northern Dezertas; 5 to Madeira and Dezerta Grande; and 3 to Madeira, Porto Santo, and the Dezertas. Of those species which inhabit more than one island, the specimens from each locality are recog- nisable as distinct races or geographichal varieties. Helix sub- plicata and papilio are found on the Ilheo Baxo; H. turricula on Cima. Of the total number (134) 112 species are peculiar to the Madeira group; 5 are common to the Canaries; 4 to the Azores, and one to the Guinea coast; 11 are common to Southern Europe, besides 2 Limneids and 7 slugs, which may have been recently introduced, viz. :-— Arion empiricorum. Helix cellaria. Zua lubrica, var. Limax variegatus. 5 cerystallina. » folliculus. » antiquorum., 5 pisana. Bulimus decollatus. > agrestis. 5, pulchella, oa ventrosus, Fer. >» gagates. » lenticula. Balea perversa (p. 293). Testacella Maugei. (,, lapicida, fossil). Limnea truncatula. a haliotidea. — . Cionella acicula. Ancylus fluviatilis. Great quantities of dead shells of the land-snails-are found in ancient sand-dunes near Canical, 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.* * Heliz tarella, 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-snails of Madeira, Helix delphinula, Lowe. M. 5 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. Gavan cylichna, Lowe. P. Santo. Cionella eulima, Lowe. P. Pupa linearis, Lowe. M. (= minutissima, Hartm ?). e >, abbreviata, Lowe. M. The problem of the colonisation of these islands receives ad- ditional light from the circumstances noticed at other oceanic islands, especially the Canaries and St. Helena. There is evi- dence that this mountain group has not arisen newly from the sea, and great probability that it has become insulated by the subsidence of the surrounding land.* The character and arrangement of its fauna is probably nearly the same now as when it formed part of a continent, and the diminution of its land-shells in variety and size may be the result of a modern change of physical conditions brought about by human agency, as at St. Helena. The annual fall of rain is now 29°82 inches, whereas it was remarked by Columbus, three hundred and fifty years ago, ‘‘that, formerly, the quantity of rain was as great in Madeira, the Canaries, and the Azores, as in Jamaica, but since the trees which shaded the ground had been cut down, rain had become much more rare.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 Islands are sixty miles west of Africa, with a temperature of 60°—66° in the coolest half year, and 78°—87° in the hottest. The land-snails are about 80 in number, in- cluding Heliz 50, Nanina 1, Vitrina 3, Bulimus 16, Achatina 3, Pupa 56, Limax 1, Phosphorax 1, Testacella 2, Cryptella1, and * See the observations of Mr. James Smith, and of Sir C. Lyell and Mr. Hartung (Geol. Jour. 1854), 7 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, 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 have been introduced (e.g., Helix lactea, pisana, cellaria); but the presence of 20 Lusitanian species, in a total of 80, is too remarkable to be accidental. The Cape de Verde Islands, although much farther to the south, are also much farther from the continent, being 320 miles west of Cape de 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—Muadeira—Canaries. » rozeti, Sicily, Morea—Algeria—C. de Verde—Canaries. », lanuginosa, Majorca—Algeria—Palma. » simulata, Syria—Egypt—Lancerotte. » Michaudi, summit of Porto Santo—Teneriffe ? » eyclodon, Azores—Canaries—C. de Verdes. », advena, (= erubescens Lowe), Madeira—Azores—St. Vincent. pliearia and planorbella, Canartes—Porto Rico? Baten subdiaphanus, Canaries—Azores—C. de Verdes. . 5 beeticatus 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 diving men im canoes.— Humboldt, ii. p. 462. 96 MANUAL OF THE MOLLUSCA, volcanic. The indigenous plants are all peculiar, and not more related to those of Western Africa than to Brazil.* The land shells are also peculiar ; 13 species have been described, viz. -— Helix, “ sp, Bulimus 5, Achatina 2, Pupa 1, 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.+ Bulimus auris vulpinus. Bulimus relegatus. » Darwini. Helix bilamellata. 3 Blofteldi. » polyodon. oo Sealei. » spurca. 5 subplicatus. 3» biplicata. xD terebellum. 5,5 Alexandri. ss 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. Iago.{ 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, or on any other part of this coast of Africa.”—R. Brown, Appendix to Captain Tuckey’s Narrative of the Congo Expedition (p. 476). 1818. + G. Sowerby in Darwin's “ Volcanic Islands,’”’ p. 73. Forbes, Journ. Geol. Soc. 1852, p. 197.—Benson, An. Nat. Hist. 1851, vii. 263. f~ 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 sheils 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 haye obtained respecting the extinct and existing terrestrial mollusks would seem to point in the samo direction, and assuredly to indicate a closer geographical alliance between St. Helena and the east coast of S. America than now holds.”’ (Forbes.) Tristan d Acunha (No. 29 of Map). Two peculiar species of Balea (Tristensis and ventricosus) are found on this remote and lofty island, which attains an eleva- tion of 8,236 feet. 3. AFRICAN 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 Folini, Bulimus numidicus and fastigiatus, Pupa crystallum and sorghum, Achatina columna, striatella, and lotophaga are found on Princes Island ; Pupa putilla on Goree Island ; Bulémus (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 “5 Corbicula, 4 sp. Egypt. Pleiodon ovatus de Tridina nilotica % Attheria semilunata ,, Nile. or aegyptiaca ») Galatea radiata 35 4, CAPE REGION. Dr. Krauss describes 41 species of land-snail from South Africa, and Mr. Benson has furnished a list contaiming 22 others; these are all peculiar, except a Succinea, which appears to be only a variety of the European S. putris, and two Huro- 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 bivalves, and 5 univalves, 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. Limax 4 — — ATION cc csceceasteonssees | Wonca] Daa V0: 31: eRpaNapeela 1 Paludina ......200-sssce 3 — IPiySaiesscccceeseeesiest nee NETitina.........cescecses 1 Witrinaieesssasecesscse. cs 4 PHYSOPSIS .......c0-0-008 1 — MT G]IX Kereesyeetassse Tete Bon MAMGYIUSia..-.c.ccceraeste 1 Corbicula .......0..s0000 1 SUCCGINEA .......cceer00e 4 Planorbis .......c.cccwe 8 Cy Clasiis-ssseccssssesees 1 IBS UMIMIUS eecccersccces.-e Le — Pisidiuti) Ceesecessseeses 1 PUDAUes emcees coerce? 1G) 8) = VAPINUIUS Hrs esseresscot aL Wil1OWacssseeceateeee eer 1 EMBOESRITEY “so00c0 conoon | 7h Oncidiumeeersees--0-2- TACHI, seessecseesonsen 1 CyclostOMa ..eccccccrve 6 AULICUIA ......c0ceccee. 6 5. YEMEN—MADAGASCAR. The S. W. Highlands of Arabia (Yemen) form a distinct Botanical province isolated by rainless deserts to the north. The land snails consist of a few species of Helix and Bulimus, Cyclostoma lithidion, and 3 species of the section Otopoma, a group also found in Madagascar. ‘Two species are common to the island of Socotra (No. 30), which also has a species (of Pupd) common to Madagascar. Bulimus guillaini, Cyclostoma gratum, modestum and Souleyeti are found on the island of Abd-el-Gouri. Very few land shells have been collected on the mainland of Eastern Africa, although it is a rainy region, and well wooded in the southern part; 5 species only are recorded from Moga- doxa and Ibu, belonging to the genera Helix, Bulimulus, Acha- tina, Pupa, and Otopoma. Onthe Island of Zanzibar are found Achatina Rodatzt and allisa, Cyclostoma Creplini and Zangue- barica ; Pupa cerea is common to Zanzibar and Madagascar. Madagascar itself is rich in land shells; Dr. Pfeiffer enume- rates— Helix 28 sp., Bulimus 6, Succinea 14, Pupa 1, Achatina 4 (one of which, eximia, is allied to A. Columna, of W. Africa), and 32 Cyclostomide, chiefly of the section with spiral ridges (Tropidophora), 3 of the division Otopoma. Cyclostoma carini- ferum and Cuvieri are found on the Island of Nosse Be; Helix guillaint on S. Maria I. Amongst the fresh-water shells are Melania amarula, Melanatria fuminea, and Neritina corona. The land shells of the Mascurene Islands are nearly all pecu- liar; we are indebted to Mr. W. H. Benson for most of the information existing in respect to them. Comoro Islands. Helix russeola and Achatina simpularia are found in Mayotte ; Cyclostoma pyrostoma in Mayotte and Madagascar. INDIAN REGION. 99 Seychelles (No. 31 of Map). Parmacella Dussumieri. Bulimus ornatus. Helix unidentata. és fulvicans. >> studeri. Cyclostoma insulare. »> souleyeti. 9 pulchrum, 5, Tranquebarica. Cyclotus conoideus. Streptaxis Souleyeti. Mauritius (32). Parmacella perlucida. Helix Barclayi. Pupa Largillierti. ” Rangii. » odontina. Cyclostoma Barclayi. oe mauritii. Vitrina angularis. 35 Michaudi. Helix philyrina. Tornatellina cernica, op carinatum, » inversicolor. Gibbus Antoni. A undulatum. 9» Stylodon. » Lyonneti. 5 insulare? - » mauritiana. Succinea sp. Cyclotus conoideus ? »» Mauritianella. Bulimus clavulinus. Otopoma Listeri, » rawsoni. 5 Mauritianus. 1 hemastoma. » semicerina. Pupa pagoda. Realia rubens. » mucronata. » fusus. » aurantiaca. » Hitella, » sulcata. » wmultilirata. ae) Dulas » Clavulata. » expansilabris. 3) Similaris. »» Modiolus. » globosa. » suifulta. » tfunicula. 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 ceelatura. Helix tortula. » etecta. » SBrandiana. »9 delibata ? Pupa Largillierti—Mauritius. Rodriguez. Cyclostoma articulatum, Madagascar ? Streptaxis—pyriformis. No. 34. Kerguelen’s Land. Welix 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 Oyclostoma 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 Helicidee and 50 Cyclostomide. A very F 2 100 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. TLC LiKe esveseatinces cess 83 Pipaieceeeresstccscesseas 7 Cyclopliorus .........06- 26. IN AMINE Pee seeseseee te caee 46 Clausiliay vecarsceesceeces otk Leptopoma ............ IL Ariophanta ........ ... 8 WARIO): decancsad eaeeacce 9 IPLeTOCY CLUS se.-a2 seers 10 SIME PIARIS)-ecsrares-ore Ab PIaNOLpis| ¢......s0s-26 . 11 ~~ Alasmodon ............ 2 FEUD: aacckwesesscscsccrcos 7 BaluGing. ...cc.sevesenen de | pAMOM ONES qecessertacaac 2 MMN BA. yn .scccpsonses 7 IVAW ALAN Sco ccse cence one 2 Cyclasm savnsiccscsecstoss 6 ANCYLUS..........00c000e Mey eR MULICUIA) ccs 6c3 ce ocaes 1 Pisidium ...........006 1 Carychium exiguum, Say, is found in Vermont, and Limnea (Acella) gracilis in Lake Champlain; Valvata tricarinata and Paludina decisa are characteristic forms. The genera Clausilia and Cyclostoma are entirely wanting in Canada and the Northern States. The Zimacide are represented. by Philomycus, of which there are 9 reputed species, ranging from Massachusetts to Kentucky and South Carolina. 17, ATLANTIC STATES, The parallel of 36° N. lat. forms the boundary-line of two botanical regions in the United States; but the evidence of the fresh-water shells, in which they are particularly rich, seems to favour a division into two hydrographical provinces—the region of the Atlantic streams and the basin of the Mississippi. About 50 fresh-water Pulmonifera, 150 pectinibranchiata, and 250 bivalves, are reputed to be found in the States, and it is supposed that only a few species are common to both sides of the Alleghanies. Cyclas mirabilis, Pisidium Virginicum, Cyrena 3,000 feet on the mountains of Scotland. (Watson.) According to Pallas it abounds on the western flanks of the Ural Mountains, but disappears on their eastern side, and is not found in Siberia. In the Pliocene period it appears to haye spread itself north- ward and westward to Iceland, Greenland, and Newfoundland, where it still grows, the only heath indigenous to the New World. (Humboidt.) 108 MANUAL OF THE MOLLUSCA. Carolinensis, and Unio complanatus and radiatus, are character- ‘istic of the eastern rivers; Melania depygis is said to be the only member of that large genus found eastward of the Hudson River. Of the American land-snails, 29 sp. of Helix, 6 Suc- cineas, and 13 Pupas are enumerated from the Atlantic States. In Florida the propinquity of the West Indian fauna is strongly indicated by the occurrence of the great Glandina truncata, by species of Cylindrella, and a Helicina. A Cuban species of Chondropoma (C. dentatum) is also said to occur in Florida, and Ampullaria depressa in Florida and Georgia. The Pulmonifera of North America haye been carefully exa- mined by Messrs. Binney,* Bland,+ and others. The following summary of North American Pulmoniferais given by Mr. Binney, The area is nearly co-extensive with our regions, Nos. 16 and 17. PATON ope ssee se ees ce seenss 2), PBUMUSE vetseeveetmones 21 ~ Melampus...........0.0. 11 MIMAKI een cnceacen sates 3 ACHAUNA cece eeeeeree 5 Cary chium i2css-ces-2¢ 1 Philomycus ............ 2 LEATIOE) iedetioanesicnctsa=s 2) ni ea eee ss seacesee 34 SVAUTIM ctype r eee censcnen ce 2 WVIELLISO) Seen ceotekecrccs 4 IPRYSaiis ecsctedestosse 19 PSTOKEGNEEY HosgasbGousb5ec 18 Cylindrella ............ 4 Planorpis’ s2scccccscecees 21 Glandinas Vereen. .cs20 Gy VieronICellayecs.. saree LY WAM Cylusies.ceeee cee 10 Jalalb:<.55- doanoncoosnan Jas0e 13] There are also found in the fresh waters of this district Mela- niade 380, Paludinide 58, Cycladide 44, Unionide 552. 18. AMERICAN REGION. 7 The mass of American land and fresh-water shells are found in the central and southern States, the country drained by the Mississippi and its tributaries. The Helicide are.not more re- markable for size and colour than those of northern Europe ; the most characteristic forms belong to the sub-genus Polygyra. (or Tridopsis, Raf.), such as Helix tridentata, albolabris, hirsuta, and septemvolvis. The truly North American forms all belong to three genera, viz.—Helix 43, Succinea 8, Pupa 3 species. In the Southern States are also found 5 species of Bulimus, 3 Cylindrellas, 2 Glandinas, and 5 Helicine, genera whose metropolis is in the Antilles or in tropical America. The fresh-water univalves include above 100 species of Mela- niade belonging to the genera Certphasia, Melafusus, Anculotus, Melatoma, and Ammnicola, 15 Paludine, some keeled, and one. * In several papers.in Proc. Acad. Nat. Sci. Phil. 1857, and subsequent years. + Remarks on the Classification of N. Am. Helices. Annals of Lyceum of Nat. Hist., New York. 1863. MEXICAN REGION. 109 muricated (P. magnifica); and species of Valvata, Limnwea, Physa (15), Planorbis, and Ancylus (5). The fresh-water bivalves are also extremely numerous: the Unionide are unequalled for their ponderous solidity, the rich tinting of their interiors, and the variety of their external forms.* Gnathodon cuneatus, Cyrena floridana, 16 species of Cyclas, and Pisidium altile, belong to this region. 19. OREGON AND CALIFORNIA. The Fauna of the region beyond the Rocky Mountains is believed to be almost entirely distinct from that of the United States. Arion (foliolatus) and Zimax (Columbianus), genera not indigenous to eastern America, were found near Puget Sound. (Gould). We have no information respecting the land and fresh-water shells of Russian America, but from analogy we “may expect to find a few there identical with those already mentioned as occurring in Siberia. + - The shells of Oregon and California are principally known by the researches of Nuttall, Couthouy, and Binney. ETC Necuesncgaavecr casa Fok) YS seeccccasaceenss seven Q — CYTONE wesseeresseneeeeee 2 PPB ULMMUS!s..cer ann <0 peed ONAN CVINIS nc nccssc neces ocen 4 Cyclas -.6.---coseennan 1 Achatina ..........0. ‘staat lANOEDIS! (lececces-seos 2 LUMO. cessscueseeseacnee i Succinea .........0000. 4 WPeLAMN IAL AS. Sodesvcees ee 2 Alasmodon ............ 1 Limnea.......cescceeeees 12 Potamides...........++0. 2 ANOGON,..40:.088-00 see 3 Limnea fragilis, a Canadian species, is said to range westward to the Pacific; and L. jugularis to be common to Michigan, the North-west territory, and Oregon. (De Kay.) Limnea umbrosa, Say ? and Planorbis corpulentus, Say, are found in the Columbia River. 20. Mexican REGION. The lowlands of the northern half of Tropical America con- stitute only one botanical region, extending from the Rio Grande del Norte to the Amazon; but on zoological grounds it may be divided into two smaller areas. The Mexican province, including Central America, itself comprises three physical regions: the comparatively rainless and treeless districts of the west; the mountains or high table-lands with their peculiar flora; and * The private cabinet of Mr. Jay contains above 200 species of North American Unionide, and very many varieties. + The affinity between the Mammalia of the Old and New Worlds is greatest in | eastern Asia and north-west America, and diminishes with distance from those regions. ( Waterhouse, in Johnston’s Physical Atlas, No. 28.) 110 MANUAL OF THE MOLLUSCA. the rainy wooded region that borders the Caribbean Sea. Tho land snails of Central America resemble those of the Antilles in the prevalence of some characteristic genera— Glandina, Cylindrella and Helicina,—of which very few species are found on the northern Coast of the Gulf of Mexico. The Bulimi are numerous, but chiefly thin, translucent species. FETC ]IK enews sce edesee 33 Glandina& ...........0006 25 WISH aiiaescacesasmeeeeoe eo Proserpina ..........6. 1 Tornatellina ............ 1 Cyclophorus ..........+. 3 J SUITS pooncoascnodepon0c SOV EAMP pal tye.t:. seteceesc tees 1 Chondropoma. ......... 3 NUGCINCA) ea-reeceenesses 6 Cylindrella ............ 20 Megaloma........ nscnote 2 Achatina (Spiraxis) .. 35 Oyclotus ....cscceveree BE Heli cinariitcc-nneoe 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 Montagne, 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°—78°, and the annual fall of rain exceeds 100 inches in most of the islands. MET CA eardieesceckenss 200 SSPUPA eevccsessencosenoet 26 Cyclophorus ........... 1 Stenopus ...........0006 2 Cylindrella ............ 73 Cy Clotus :-.-c.cecese- es 14 psHkez eh oseeonoccnpoounaace CA) GIEATSITES “soodcccecmnosa5 1 Megaloma............. mo Proserpina.......... Reon. “MAIC A sles cons Seunessesees Ls elicina, ccs basceas 43 PS WITIUSsecceeres ce cusses 53 Succinenyespscccsceteerer 16 ATGAIay «.c..-sesssessnens 1T A Chatina i. ineccdosvere— Genera which attain their mazima in the present seas are thus expressed ——=a@y 7 Land and fresh-water shells of existing species are found with the fossil bones of the Mastodon and Megalonyr, in N. America. (Lyell.) } The number in each formation depends on the extent to which it has been investi- gated, and on the opinions entertained as to the strata referable to it. Professor 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 :—Paleeozoic, 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 conyeys 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. t * 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 én additional “* Formation,’’ much less a ‘‘ Quaternary System.” + It was on this account that Professor Sedgwick proposed the term “ Paleozoic,’ rather than “ Protozoic,” for the oldest fossiliferous rocks. | TABLE OF CHARACTERISTIC GENERA. 123 II. TABLH 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, Phr:gmoceras, Trochoceras, Ascoceras. Ba STLWREAN) scvcessecaes j theca Holopella, Murchisonia, Atrypa, Retzia. Cardiola, Clidophorus, Goniophorus, Grammysia. | Bactrites, Gyroceras, Clymenia, Apioceras, Serpularia. 8.. DEVONIAN .......0008+ ~ Spirifera, Uncites, Merista, Davidsonia, Calceola. Stringocephalus, Megalodon, Orthonota, Pterinea. 4, CARBONIFEROUS Naticopsis, Platyschisma, Metoptoma, Productus. Aviculo-pecten, Anthracosia, Conocardium, Sedgwickia. Camarophoria, Aulosteges, Strophalosia. Myalina, Bakewellia, Axinus, Edinondia. Denn ecer ae: Discites, Goniatites, Porcellia. Fa PERMIAN, .f.+.0-02. : Ceratites, Naticella, Platystoma, Koninckia, Cyrtia. Monotis, Myophoria, Pleurophorus, Opis. ‘Belemnites, Beloteuthis, Geoteuthis, Ammonites. Alaria, Trochotoms, Rimula, Pileolus, Cylindrites. Waldheimia, Thecidium, Spiriferina, Ceromya. Gryphea, Hippopodium, Cardinia, Mycconcha. Coccoteuthis, Leptoteuthis, Nautilus. Spinigera, Purpurina, Nerinzea, Neritoma. Pteroperna, Trichites, Hypotrema, Diceras. lrigonia, Pachyrisma, Sowerbia, Tancredia. eooccesece 8. U. JURASSIC........ 5 Crioceras, Toxoceras, Hamulina, Baculina. Requienia, Caprinella, Sphera, Thetis. Belemnitella, Conoteuthis, Turrilites, Ptychoceras. Hamites, Scaphites, Pterodonta, Cinulia, Tylostoma. Acteonella, Globiconcha, Trigonosemus, Magas, Lyra. Neithea, Inoceramus, Hippurites, Caprina, Caprotina. 9, L. CRETACEOUS ... 10. U. CRETACEOUS... Beloptera, Lychnus, Megaspira, Glundina, Typhis. Volutilithes, Clavella, Pseudoliva, Seraphs, Rimella. Conorbis, Strepsidura, Globulus, Phorus, Velates. Chilostoma, Volvaria, Lithocardium, Teredina. Spirulirostra, Aturia, Vaginella, Ferussina. Halia, Proto, Deshayesia, Niso, Cassidaria, Carolia. Grateloupia, Artemis, Tapes, Jouannetia. TISSEOCENE <.ccccscsceees 1 12. MIOCENE .essessoeeee Argonauta, Strombus, Purpura, Trophon. Yoldia, Tridacna, Circe, Verticordia. a 13. PLIOCENE............ saa SRN ET ae ee ee a eae a In q q ty bh mn La Q 124 MANUAL OF THE MOLLUSCA. III. RANGE OF GENERA IN TIME. Order of Appearance. Cambrian Silurian Devonian Carbonif. Permian. L. Jura. U. Jura. L. Cret. U. Cret. Eocene. Miocene. Pliocene Trias. bs oH s. oe x io} in at (o) 5 & ©) lon 2, (= mn || | | | Gomphoceras, Bellerophon, Pentamerus | — — Orthis, Conularia, Murchisonia................ | —— —— — spiitera, Athyris, Posidonomya ..-... 0... hese eee | Genera, arranged in their ; a ¢ MSOAILCA cana de [oee- ctor cess esiaiceecsais ster vaca docdan| (ere ee eee |e Werebratula, PinnaCyprinaiss. 00cm nee ph ea) Seen ATG ATV Egy oe beets satigan seme secant se el GervilliaViyoconcltap-sss.-s-qo-ceeeee eee —|——— — — Ammonites, Naticella, Opis .........c...0006+ —-— Trigonia, Isocardia, Thecidium Cerithiumy Plicatulay @andita is. semua tall’ giytipvcena ull’) Wee eye wee es ecccrece eercesccccae Seecccsece Cec ceseeserecs 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 Paleeozoic fossils, it must be understood that they are only employed in default of more exact infor- mation. Buccinum, Melania, and Mya have been long since expunged; and Modiola, Nucula, and Natica, are only retained until the characters which distinguish them are better under- stoad. RANGE OF FAMILIES IN TIME. 125 IV. RANGE OF FAMILIES IN TIME. Setter tee Babec oat aq SaS8 SS i 5 Ses of Strata. qGes 3 Ge eas 2288 = S oO “ot 4 Os) =| 62a Se|AH45u5 |B am FAD GOWAN EG Ce (occ noccaecececnasisleasselroseinstel a Teuthidee—Sepiadee ...........ssesceceeneee Bain eh pede ||) ke eS HEE CMMI 2 Na wctctee ts ceinie < aonssict ines sols seielasln:» pa Bite eee PNGHIEIT COM meee to ees cchccecstere dest cesses ee a i ee ae aa PANIIT TATA ce ees iese on iewsls xcaiescinssiccelsiaacice ce BN eee Fes eee pes OetHOCERACCEG 20......25..0-222ceeeeeneeree |= —— 2 Atlantidze—Hyaleide ..........ss00eee088. | = —— — — | —— — —— | —-—— — Strombidee—Buccinide@ ...........000606- ara sae een id COMI —VIGNHIG oils ececaccesesteweons oh: le eats Naticidee—Calyptreeidee ...............06 Sees || ee Sees a eee Pyrenean ee). ...<--2s.cccssennascucesecsee P| — | —— Be Ae Cerithiadee—Littorinidze.:......000000058 | 0 eye See Ne Turbinidee—Ianthinidee .................. | —— — — — | — — — — — ae ee Fissurellidee—Tornatellide..............5 ee aS RD eee on Neritidee—Patellidae .:.......0-csecseceeerss | ASR See, eee ee WD eriiealr rm oemeee ne secc cok ccswesescdebecsiee cece See | ele ee | eae GHIEONIE | ec eocccckccsccccrccecccccecceeeses | —— — | |] SS — PETE eee ac seas sae oeaen ooeeeccueeanas ery eee 2) |) Bere oe Te Helicidze—Lim acide .............000+006. cease ae armePiGce—MlClANIAGe: calecedcceceoussse | ee eee Auriculide—Cyclostomide............... —|-——-— ERETEDEADUM Gee maa ccmieneslacciels scicaiy smicciel see Se SS TDS LOVEE. cy ss soncs Seer ESE SHOE Se S|) ee | SHUge ree OLUNICce! sects scsesescesseess | — Productidiey....i25.-ctsdesssdeceessecs ees | Craniide: —lumnpulide ...:.......---------. | =— = = — | — = — — — | CU iRIME soe es... auch fa Tehiiee sae seeciese'e comeees ee ee — agi enibighee—WEy ENNIO cone eee nese ecccpan sce Pe A Pop Fee EES TIGRE )ege sy cepseo dn eos eee | aes Dina anan Loree mein setae iat cic hisiers ria Mareis ots clgeie isis ————————— Chamide—Myade.............++ utr Maen ai. A umeaiiet Sil lates jaa dest tesd SEE ye ee PENG UMMA CE toe «ne ote se-eeeciee nce evens ——— MUTAGEN CED ees sack arias se escekeecsctiomsioeties = @ardiads2— ACTING. oo... cs 2.0 ee eeeeer ee |) He SS CHG RICE Soacosdoanrse ssucnonebouaaucEaseoTee ee |] SS Cire Ueki ned es eaeeneeecn eb eapds || = use) hee. VAStartiec.....ccccccccccccceccsccsccscsescececee fo | ee | Veneridae— Lellinid2, ..c.2c..-.e0e0se'sere% Be cE Fe, ee et Vievee lel cee sean ce iaceGted scewaascuases «cscs =) (a Oe ee ete hae. tactic coca ssa ceaseasueeorens [ego an) l) Ames eee) Ek | Gastrocheenide-—Pholadide ........... | =| ————|--- Distribution of Families of Shells in Time.—Employing the term ‘“‘families” for natural groups of genera, and adopting the smallest possible number of them, we find that sixteen, or nearly one-fifth, range through all the geological systems. Only seven have become extinct, viz. :— Belemnitide. Spiriferide. Hippuritidee, Ammonitide. 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 geriera 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 Paleozoic 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 Palzeozoic, 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. eI os is) So 3 GEOLOGICAL sig 2 2 & || N en of | 3 SYSTEMS. Genera.| 3 ‘3 |g Species Pra a # | = |\@’Orbigny).| 3 o m (e) o A|o ENyeie WyCamnbrian.<..2.0....+...: 11 362 | 18 < pisabummamys \S20Gisscecs. 13 3l7 20 O82 EV OMIAN .2.....cvcese ones 20 1035 24 $32 3 § Carboniferous ............ 23 835 30 a WBS ra AT 3d eld a ced 20 74 30 Lol ae 31 713. | 35) ui I LiF SUTAISICN.. cee. ctees 48 1502 42 B U. Jurassic .............. 50 1266 49 57 S| 6 id Cretaceous ............ 53 7184 52 g U. Cretaceous............ 59 2147 56 n oan pe ses) |e Pewee Lda a IBGOBOS soc sadoesoscoscarcoc 72, 2636 60 a jd Miocene’ ¢...-..........0.. 16 2249 60 ae PaTOcanenttds:: ict 437 62 (78 = MRS COM bissereaccscecesse ies 16,000 78 BH seeeeee 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 paleozoic 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 o7 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.+ 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. 7 + 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 Belemnitidee) were respectively the first de- veloped. Amongst the Brachiopoda the hingeless genera attained their maximum in the palzeozoic 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 Verebratulide 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 paleeozoic strata by several genera closely allied to the diminutive Atlanta and Scissu- rella, and by others perhaps related to Janthina. The Naticidce and Calyptreeide 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. 4 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 have not always existed. In the first place it will be noticed that the mass of the stratified rocks are of marine origin, a circumstance, not to be wondered at, since the area of the sea is twice as great as the land, and probably has always been so; for the average depth of the sea is much greater than the general elevation of the land.+ 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 Lepadide, 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 lusus nature, but in truth the ordinary horse is far more wonderful. Un- fortunately, a new “ vulgar error” has arisen from the terms in which extinct animals have sometimes been described, as if they had been constructed upon several distinct types, and combined the character of several classes. { 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. 9 Go 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 interval since the Cambrian epoch. The average duration of the marine species has been assumed. at only one-third the length of a geological period, and this harmonises with the fact that so few (either living or extinct) have a world-wide distribution. The life of the land-snails and of the fresh-water shells has been of longer average extent, enabling them to acquire a wide range, notwithstanding their tardy migrations. But when we compare the estimated rate of change in physical geography with the duration 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, yiz.—Pecten polymorphus, a Medi- terranean shell; and Lutraria rugosa, still found on the coasts of Portugal aud Mogador. Tertiary hile —If any distinction is to be made between “Tertiary” and ‘‘ Post-tertiary”’ strata, the former term should be restricted to those deposits which contain some extinct species. And the newest of these, in Britain, contain an assemblage of Northern shells. Professor Forbes has published a list of 124 DISTRIBUTION OF THE MOLLUSCA IN TIME. 181 species of shells from these ‘‘ cies 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 Cobboldice, Pl. 17, f. 18). At Chiliesford, Suffolk, Yoldia arctica and myalis occur of large size and in excellent preservation, with numerous specimens of Mya truncata, erect as they lived, in the muddy -sea-bed. TZrophon scalariforme, Admete viridula, Scalaria gron- landica, and Nativa grenlandica, also occur in the Norwich Crag ; and Astarte borealis, with several arctic forms of Tellina, 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 Linnzus. 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.+ 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, Columbella, 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 Trophon, Crepidula, Monoceros, Pseudoliva, Voluta, Oliva, Crassatella, and Solenellu. 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 Eocene tertiaries we perceive the “dawn” of the present order of things. All, or very nearly all, the species are different, but a large proportion of the genera are still existing, though not always in the seas nearest to the localities where they occur fossil. Thus in the London clay are found—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 having prevailed, in the latitude of England, than that which marks the period of the London clay. | And this is not more than can be accounted for by such a cause as the flow of an equatorial current from the direction of the 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 Ichthyo- saurus were found at Exmouth Island, the farthest point reached by Sir E. Belcher’s expedition. DISTRIBUTION OF THE MOLILUSCA IN TIME. 138 The peculiar physical conditions of the Chalk period are represented at the present day, not so much by the Coral Sea, as by the Aigean, where calcareous mud, derived from the waste of the scaglia regions, is being rapidly deposited in deep water. (Lorbes.) 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 Trias, with its foot-prints of gigantic wingless birds, has been compared with the state of the Mascarene Islands only a few centuries ago, and with the New Zealand Fauna, where birds are still the highest aboriginal inhabitants.* 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.+ Geologists gene- rally have abandoned the notion, once very prevalent, of a universal high temperature in the earliest periods; a notion which they had derived from the occurrence of certain fossil plants, corals, and shells in high latitudes. The absence of remains of mammalia in the paleeozoic 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 great extinct wingless birds of New Zealand, Professor Owen suggested the notion of land having been propagated like a wave throughout the vast interval between Connecticut and New Zealand, since the Triassic period. + See also the Rev. J. G. Cumming’s “Isle Of Man” (1849), p. 89. £ Views of Nature, p. 221. Bohn’s ed. 134 — MANUAL OF THE MOLLUSCA. nay, often seemingly producing results opposed to @ priort 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. INEriti Geer its. snectee ees 428 103 Argonautide ..........,. 4 2 Patellidse ..........0.00. 368 104 Octopodida@........1.+,.+- 63 _ Dentaligdze...... is... 40 125 Meuthidcec ts es.eokeror st 104 31 Chitonidve spans 250 37 Belemnitide ............ — 140 —— = Sepiade ........ccceee 30 16 ( 8,465 5,819 Spirulide..........s.000 3 = _ aR ee ahi Rom Hrelicid sae reeasseeseeeres 4750 316 204 189 Limacide ediadtvetess 93 4 Tetrabranchiata. Limneidze ASR ees ee 185 Nautilidg .........00000 6 ae (MArine)...0. esseseeeeee ee 37 Orthoceratidee .,,...... i (Ditto, shell-less) ...... 36 — Ammonitide ............ — 1600 5.404 “542 ae RA Operculated Pulmonifera. 6 2193 Cyclostomide............ 903 45 GASTEROPODA. Prpsobranchiata, ACICULIGE .cececcecececee 28 feet Strombideyt ............ 87 393 — _—- MUTICIDE WV, 5..2200.00 +e 993 703 931 46 Buccinide «.....1.0+ 1,144 352 Tecti-branchiata. Conide ....... PEyL Chee 856 462 Tornatellide ............ 62 166 Volutidae: 2. -L.utsa8. «sade 686 210 Bullidee ....eseerereeee 168 88 Cypracidae ......2.:.::--- 227 97 Aplysiadee ............. 84 4 Naticidee meme teeta. 268 340 Pleurobranchide ...... 28 5 Pyramidellide ......... 216 304 Phyllidiad@ «1.15... 14 — Cerithiadse ............... 192 610 "356 963 Melaniade ............... 424 50 Nair achat See aca BoP O) ey PO dy wanoridiih oy JURE In 160 = Littorinide ............... 410 220 Thine 38 ce Paludinidee .............6+ 217 110 PSOne eter ale 101 = Calyptreeide ... ........ 160 10] Phyllirhoidee ...... rh.) 6 poe. Turbinidee S500 00059000900 855 906 Elysiadze abe maa Vinde Wi. . 13 a Haliotide ............... 104 136 eS Fissurellidz ............ 201 76 318 * Burchell, in Darwin’s Journal, p. 87. } Including Aporrhais t With Scalaria. NUMERICAL ESTIMATE. Recent. Fossil. Nucleobranchiata. MITOGEN eccceensecsc ss cice 33 Atlantidge ..........0000. 22 55 PTEROPODA. Hyaleid® ...........000+ 52 Limacinide «........... 19 QUIGHINE inns cxweveiesenses 14 85 BRACHIOPODA. Terebratulide ......... 67 Spiriferide ............64. _ Rhynchonellide ...... 4 Orthidee eh. dadevscae sees _— Productide&............... _ Cranlad dey. ceases os sacle 5 Miscimidser .0..ckse-003 10 Lingulidse ............06 16 102 135 Recent. Fossil. CONCHIFERA. OStTCIADE .....ss0cceseree 426 AVIGUIICGEY cesccsscceresee 94 Mytilidee ...........seeecee 217 IAN CAUSSE etecosscevsnsstes 360 TrigoniadZ.......eecccee 3 Unionid@ wrecorecerosece 549 C@laimidceyeccnesss--see0s 50 Hippuritide ..........06 _ Mridacnidss:...ccesccoes se 8 @ardiad ices eesce state 200 IUCIMIDEE ss seen coves salto 178 Cycladid@ ....00.2.0.0000 176 Cyprinde .......00.0-000 176 IVETIETICse!) rece sescceres 600 IMiaC bri dae)t sete es -selees 147 MeNimi dee). sase-ces », = Sl _— SSE 4 OSS x | EQ SOS é SSN SOX SANS A | EX xO eT ot i Fig. 32. A Trawl-net. A. Side view; B. Net in op ration; C. Plan. nished the following sketches and particulars :—‘‘ B, Fig. 32, is intended to represent a trawl-net at work on the bottom of the sea. * Admiralty Manual of Scientific Inquiry. 8vo. Lond. 1849. t Voyage of H.M.S. Rattlesnake, vol i. p. 27. 140 MANUAL OF THE MOLLUSCA. The side frames are of iron, the upper beam of wood, and the lower edge of the net is kept down to the ground by means of a chain, which is wolded or wrapped round with old rope. The beam is generally from 40 to 50 feet in length, and about § inches square. The net is about 30 yards in depth, and has a couple of pockets inside. The end is untied when the net is hauled on board for the purpose of taking the fish out. These nets can only be worked where the bottom of the sea is free from rocks. They are used by boats of 35 to 60 tons, manned by crews of from four to six men and two to three or four boys. In the vicinity of Scarbro’ they fish between the shore-reefs and the off rock, which is 4 to 10 miles from land; the bottom is sand or clay, with 4 to 15 fathom water on the land side, and 17 to 25 fathoms on the off side.” Immense quantities of crustacea and shell-fish are taken with the trawl, as well as ground-fish. Kettle-nets.—On the flat, sandy coast of Kent and Sussex, the mackerel-tishery is pursued by setting up stakes 10 or 15 feet high, at distances of 10 feet apart, in limes running outwards from the shore at high-water, to low-water neap tides, where they are turned in the direction of the tide. To these stakes nets are attached, and leaded, which remain as long as the fish are on the coast. Cuttle-fish are frequently taken in these nets. Deep-sea Fishery.—In North Britain an extensive ground- fishery is conducted by means of long lines—often a mile in length—with hooks and baits every few yards. These lines are laid out at night near the coast, and taken up the next morning. When used out at sea, the boats lay by for a few hours, and then take up the lines. The carnivorous whelks - adhere to the baits (which have not been seized by fishes), and sometimes a bushel of them are taken in this way from a single line. Lhynchonella psittacea, Panopea Norvegica, Velutine, and some of the scarce Fusi, have been obtained from these lines, the bivalves having been entangled accidentally by the hooks. For trapping whelks on rocky ground a net may be made such as is used for crabs and lobsters, by attaching a loose bag to an iron ring of a yard across. This is fastened to a rope by three equal strings, baited with dead fish, and let down from a vessel at anchor, or, still better, from a buoy. It 1s put down over-— night, and hauled up gently in the morning. Mr. D’ Urban informs us that Natica Aldert and monilifera are frequently found in the lobster-pots at Bognor, Sussex, which they enter to feed upon the bait. Dredging. —The dredges used in the oyster and whelk- ON COLLECTING SHELLS. 141 fisheries are so- rudely made as to injure the more delicate marine animals, and suffer all the minute things to escape. It is thereforé necessary to have instruments specially adapted for the naturalist’s work. Fig. 33 is a plan, and Fig. 34 a side- view, of a small dredge, belonging to Mr. J. 8S. Bowerbank, and suited for such - work as a private collector might do on the English coast. It is made of wrought iron, with movable joints, so as to fold up and carryin the hand. The bag attached to the dredge is formed of two pieces of raw hide (A, h), connected at the ends and bottom by net (n) made of cod-line, to allow the water to escape; and is fastened to the frame with copper wire, through the eyelet-holes. The towing- rope is attached to the rings (r, 7), and when thrown overboard it scrapes with one or other of the cutting edges (e, e’). The opening is made narrow, to prevent the admission of large and heavy stones. Dredging should not be attempted in a rowing-boat, unless near the shore, in smooth water, and with a depth not ex- ceeding 5 or 10 fathoms. It may bey managed in a light boat by two persons ; one rowing, the other holding the rope of the dredge which is passed overboard near the stern. The whelk and oyster-dredgers employ a decked sailing-vessel, and work several dredges simultaneously, each requiring a person to manage it, 142 MANUAL OF THE MOLLUSCA. The dredges are put overboard on the weather-side, and the ropes made fast to a bulwark or thwart; each dredger holds the rope in his hand, after giving it a single turn round a thwart r ‘‘belaying pin,” to regulate the strain by means of the spare line. When a sufficient distance has been traversed, or the ropes strain with the weight of mud and stones, the vessel is brought to, and the dredges hauled up and emptied.* The length of line required is about double the depth of the water. If the line is too short, the dredge will only skim the bottom ; if too long, it will be in danger of getting fast. When the bottom is loose sand or soft mud, the line must be short- ened, or the vessel have more way, or else the dredge will be apt to get buried. The strength of the line ought to be sufficient to anchor the vessel in smooth water,—though not, of course, when there is much way on her,—so that if the dredge gets foul it is necessary to let out the spare line and relieve the strain while the vessel is brought round. The dredge will then usually capsize, and may be hauled up. If the bottom is at all rocky, a small strong dredge is best. The line must be shortened, and some additional precautions may be taken, such as fastening the rope to one ring of the dredge, and tying the other with spun yarn, which will break under a sudden and dangerous strain, and release one end of the dredge. In dredging on coral-ground, Mr. Cuming employed a 3-inch hawser, and had a patent buoy attached to the dredge by a 1$-inchrope. More than once the hawser parted, and the dredge was left down all night, but recovered the next day. Mr. McAndrew’s researches on the coast of Norway were conducted in the Naiad, a yacht of 70 tons, and extended from the shore to 250 fathom water. The dredge employed was at least twice as strong and heavy as the one we have represented, and all forged in one piece, instead of folding up. The bag was fastened on the frame with thongs cut from the hide. Before using, it requires to be towed astern for a couple of hours, to soften it. In three months’ work only two cow-hides were used, and one of those was torn by accident on sharp rocks. Several spare dredges were on board, in case of emergency, but not used. Dredging in deep water (50 to 300 fathoms) can only be done * The collector may go out with the fishermen and superintend his own dredge almost any time of the year, although oyster catching is illegalinthe summer. The scallop-banks off Brighton are in 15 fms. water, and nearly out of sight of land. It is not always possible to work over them and return the same night. ON COLLECTING SHELLS. 1438 _ in calm weather, with a light breeze. The yacht is brought to _ the wind (by putting up the helm), the foresheet hauled to windward, mainsail hauled up, and mizen taken in; the gaff topsail also hauled up; she then drifts to leeward, and the dredge is thrown overboard to windward, with the line made fast amidships; the spare line being coiled up so as to be given out readily. When the dredge is to be hauled in, the rope is passed through a movable block, fixed to the shrouds, and the whole strength of the crew (fifteen hands) called into requisition, if necessary. When the depth does oot exceed 50 fathoms, the boat, with three men and the two dredgers, is used. If the dredge gets fouled, the rope is passed into the boat, brought over the dredge, and hauled up. In very deep water (150 fathoms) the line is carried forward and made fast to the bows, and the yacht itself hauled up till right over the dredge, which is then recovered without difficulty. The contents of the dredge are washed, and sifted with two sieves, one ‘‘4-inch,” the other very fine. They are made of - copper wire, and one fits into the other. The dredge is emptied into the coarse sieve and washed in the sea from the boat, or if in the yacht, they are placed in an iron frame, over the side of the vessel, and buckets of water poured on. The sediment retained in the fine sieve may be dried and examined at leisure, for minute shells. : The following ‘‘dredging-papers,” kept on the plan recom- mended by Professor E. Forbes, have been selected by Mr. Barrett, to illustrate the kind of shells found at various zones of depth. The shell-fish obtained by dredging should be at once boiled, and the animals removed, unless wanted for examination (p. 153). The bivalves gape, and require to be tied with cotton; the opercula of the univalyes should be secured in their apertures with wool. The small univalyes may be put up in spirit, or glycerine, to save time. In warm climates the flies and ants assist In remoylng any remains of the animals left in spiral shells, and chloride of lime may be necessary to deodorise them. M. Petit de la Saussaye has given very full instructions for collecting and preserving shells, in the Journal de Conchyliologie for 1850, p. 215, and 1851, pp. 102, 226. It is stated that both the form and colour of molluscous animals may be preserved in a saturated solution of hydro- chlorate of ammonia (10 parts) and corrosive sublimate (1 part —first dissolved in alcohol), but the preparation is expensive and dangerous. 144 MANUAL OF THE MOLLUSCA. DREDGING PAPERS, AND RECORDS OF RESEARCHES ON THE COAST OF NORWAY. By R.. McAnDREW, Esa., AND Lucas BARRETT, Esaq., F.G.S. Date Locality 550 ID en uliaye eso ale-ciaecs Ground ae. Rock and sand. | Number Number Species. | of living of dead specimens. | specimens. Mya truncata... ... 6 Many. Tellina incarnata ... ... ws Many. Many. Astarte compressa... ... ... 1 0 » borealis Aaailieac 3 Many.'"* Cardium edule... ... ose Many. Many. Crenelladisconsi es) yeas) ses) utes: Many. 0 Acmeza testudinalis ... .. Many. 0 Margarita undulata aes 6 0 ae helicina Ee 8 0 Littorina littorea ... ... ... Many. 0 . rudis Det gation tans Many. 0 Lacunavincta... ... ... 2 0 Natica pusilla... ... 22. ws 2h NPA 0 ea CLAUS Amis tinsel ore! toes Many. 0 Purpura lapillus ... ... ... Many. Many. Buccinum undatum ... ... Many. 0 A GYAaANeUnW) eee) ese Many. 0 Belathurricnlay. yee. dees less 10 0 Doris Johnstoni ... ... ... 8 0 TL; July 1st, 1855. Tromsoé (Nordland). Between tide marks. | Observations. In sand. In sand. On sand. On sand. In sand. Covering the under sides of stones. On rock. On weed. On weed. On rock. On rock. On weed. On sand. On rock. On rock. On rock and sand. On rock. On rock. (NOTE.) Nospecimens of Trochus or Patella vulgata occurred. Date’ 2. _ Locality Depths. Sieesy ree \uset Distance from shore .. Ground... eve TT. July 5th, 1855. Near Hammerfest (Finmarken). 7 to 20 fathoms. Close to shore. Nullipore and sand. Saxicava arctica ... so. see vee Mya truncata ... 11. 2. soe vee Thracia CONVeXa ... .. se Tellina proxima ... 1. .. IMactEATellipiGh jrect cco) lites. wes Venus ovata ...0 20. sen see cee 5 UELREENRTIES "565° G00 Cyprina Islandica... ... Astarte COMpressa... ... se. Cardium fasciatum ... ... Modiola Modiolus ... ... ws. sae 29 phaseolina 9 BCookoue once * The accented numbers im the column of “ dead specimens” refer to disunited valves of Conchifera and Brachiopoda. DISTRIBUTION IN DEPTH. ; 145 Number Number Species. of living of dead Observations. specimens, | specimens, MGGwGaAUdAtace Voss lscel) wee ees 2 1 Pecten Islandicus ... 0 2! Chiton asellus... 2 0 >> marmoreus... 200 2 0 ACGME VIFGINEA 20. see ses wee 3 2 FS testudinaria ... ... ... 0 1 Patella pellucida Scoot eee 6 0 Dentaliumentale’... 0... f25 se. 4 PPS oat Trochus tumidus ... ... ... ... Many Many. POeEMECIUNCTATIISS.. sys. xt: ces 1 0 Margarita helicina... ... ... ... 12 0 oo ROTC ATA ee ee) ene | elas Many. - cinerea ... 6 2 Velutina leevigata ... 0 1 Buccinum undatum ... ... ... 0 3 Trophon clathratus ... ... ... 1 0 35 Gunner ee eeee 1 0 Bela rufa oomsecceilinics 1 0 BS UULNIGUIALO.) ces. Ws. 0 4 Mangelia nana ... ... 2 0 III: DatCmescaiiess) vets sould Ulyrord, 155, Locality ... ... ... Island of Arnde (Finmarken).. Depth es) s-. "ast ee 40to 22 fathoms. Distance from shore ... Half a mile. Ground... ... ... ... Laminaria and red weed. Saxicava arctica 25 00 3 Many.’ PUHTAGINCONVERA ces. cs5 se ase 1 0 Venus ovata doo da i 3! Cyprina Islandica ... ... ... 2 Many.’ Astarte crebricostata ... ... ... Many. Many. >» elliptica see pea 12 Many RRCOMMDECSS Ay) cecnticcen fore Many. Many. Cardium fasciatum ... ... ... Many. Many. Cryptodon flexuosus ... ... ... 1 6' Modiola modiolus.., ... ... ... 1 Many.’ Crenelladecussata... ... ... ... Many. Many. Heda permula, 0°... «0 He Many. Many. Pecten Islandicus... ... ... ... 3 Fragments. Young. Anomia Ephippium ... ... ... Many. 0 PCHICALD, ae sa. oss cae Many. 0 Chiton marmoreus... ... ... ... 4 0 Dentalium entale ... ... ... ... 4 Many. PETOCHUSMUMIGUS “Seo fas, sey oes Many. Many. SC INGLATIUS cee tee ses) | cee Many. Many. Margarita cinerea... ... 2.2 os Many. Many. AM MINOW aca eee ese eee Many. Many. el EMCI eee Weary. eae Many. Many. MiACUMAVANGtare chs See Lose 8 oes Many. Many. Hattorina littoralis.... $.:, 0... .:. 3 0 RISSOAMPALVA cco) ace, seen sos. ose Many. 0 Natica clausa ... ‘ 4 0 SsmDUSI Area | es 0 1 Velutina levigata ... Bo Ne 3 0 EP MOXAIS | 2 ees Sk 1 0 H 146 TTT [aEnEnEEEEEEEEETT EE MANUAL OF THE MOLLUSCA Number Number Species. of living of dead Observations. specimens. | specimens. | ih reels rte a2. 5 op Na eB Le eae Trichotropis borealis 3 0 | Nassa incrassata 1 0 | Mangelia nana 8 0 : Bela turricula... Many. 0 Trophon Gunneri ... 12 0 » clathratus... 3 0 IV. Date... July, 1856. Locality ... Vigten Island (N. Drontheim). Distance from shore... Quarter of a mile. Depth ... 30 fathoms. Ground... Coral-bank. Arca nodulosa... Leda caudata... Yoldia lucida ... Astarte succata : Pecten Islandicus ... Lima excavata Lucina Sarsii ... - Cryptodon flexuosus Modiola phaseolina Anomia ephippium Venus ovata Terebratulina caput-serpentis Cluton aselluss.-9... 22. |... Puncturella noachina : Emarginula fissura ae crassa... Margarita cinerea... ... 3 alabastrum ... Trophon barvicensis Matey Zachos) | tls Locality Omnaesée ( Nordland). Depth ... ... 080 to 50 fathoms. Distance from shore... Half a mile. Ground... Stones and sand. No. of hauls Four. a a a Saxicava arctica ... ... .- «. 6 2 Tellina proxima ... .-. ww. + 0 1 Venus ovata . Ba sis oa 2 0 Small. Cyprina Islandica .. 2 Many. Astarte elliptica 4 0 COMPTeSSa... ose 6 0 Cardium fasciatum Bo hae 2 0 A SUCCICUM.:. <2. «00 5 4! Modiola phaseolina — see 200 f Many. Large. Crenella nigra... .-- 00 ss. 0 1 Large. Nucula nucleus «2. aa. se 0 | 5 Fy) LE DUIS|s061) tour iaasl eens 4 | Many. Leda caudata... .2. see ues «+s 2 0 Arca pectuncu.oi idea hecgertes m=. 12 | 10' Large. 3 5) 2 0 3 0 3 4! 0 9! 0 IY | 0 1 2 0 10 0 Many 0 2 20 Many. 4 0 2 0 1 2 0 1 1 0 1 0 1 0 We June 23rd, 1855. Date ... Locality Depth ... bao Distance from shore .. Ground... eon No. of Hauls Cyprina Islandica ... ... Newra cuspidata ... ... Leda caudata... .. ... Woldialucida <4. ss Pecten Islandicus ... Se SUQUIS ee eva Arca pectunculoides B00 Syndosmya prismatica... Cryptodon flexuosus Mactra elliptica ... ... Cardium fasciatum ... SSUCCIGUIO cs. Astarte sulcata Anomia ephippium 500 Crenella decussata,.. SSN eTUL eee Terebratula cranium Rhynchonella psittacea... Dentalium entule .. Puncturella noachina ,., Lepeta coeca ... ... 4. Pleurotoma nivalis .. edo bee July 20th, 1856. 147 Observations. Large and Recent. i Many stones had on them the attached Large. Carinated Var. Young. DISTRIBUTION IN DEPTH. ~ Number Number Species, of living of dead specimens. | specimens. Pecten striatus... uae 2 0 PMMDIOTINUS! 4h) ise} ccae) cok 3 6 PEMPUSTIUTTS is cee | saeh) ans vou 1 0 PEISIAACIGUS <6. Ach gus) ant v) l' | Terebratula cranium ... .. 4. 80 10 Terebratulina caput-ser pentis a 1 0 | ‘Craniaanomala ... ... wo 12 0 valve, Chiton Hanleyi ... 4. wn 3 0 MIE NCLATCUE CAs oye bu ace on 4 0 Acmea virginea ... ... ws 10 6 Pilidium fulvum ™ bc bad Many. 4 Puncturella noachina Rae RAG 2 1 Trochus millegranus ... .. 2 0 aalma polita... ssc ese us 1 0 Natica nitida ... ... BS 3 2 » helicoides ... a 0 1 SepUSUars.- se. ais 0 1 Veiutina levigata .. se 1 0 Tr ichotropis borealis eye as 6 3 Nassa incrassata ... ... il 0 -Fusus antiquus ... ... .. 0 2 Trophon clathratus... ... . 0 1 Mangelia twricula... ... ... 1 0 Tornatella fasciata ... ... 0 2 Buccinum undatum ... .., 6 0 Pleurotoma nivalis... ... ... 10 16 VI. North of Rolphsoe (Finmarken), 180 to 180 fathoms. Half a mile. Sand. Two. 0 3 0 2! 0 3! 1 2! ) Many 0 1 1 0 0 1 0 1 0 Q"6! 0 2 0 3 1 0 Many. 0 2 Many. 0 2! 3 0 1 2 Many Many. Many. 0 2 0 1 2 Small. 148 MANUAL OF THE MOLLUSCA. Number Number Species. of living of dead Observations. specimens. | specimens. ay Fusus? sp... 0 Fry. Buccinum Humphreysianum 0 1 Belaturricula... . = 2 0 Margarita cinerea. 3 4 5 undulata 0 2 alabastrum .. 0 1 VII. Date een. sa ..mOUly 2th leap. Locality ... ... ... Off the Island of Arnée (Finmarken). Depth ... ... ... ... 200 fathoms. Distance from shore... Four miles. Grounds :i--- -- --. suds Pecten similis... Cryptodon flexuosus Neera cuspidata Arca pectunculoides Nucula tenuis ... Yoldia lucida .. : Modiola phaseolina Cardiura suecicum... Crenella decussata... Astarte crebricostata Terebratula cranium Dentalium are Asis os ‘is quinguangidare (Forbes) Eulima bilineata ... Eulimella Scillee Mangelia trevelliana Bela rufa... . es Philine quadrata spc SCOOCOCONFRRFOCOFPNNRNYK- ORO PrrPwnhbooanwhhkooonaowrorns DREDGING PAPERS, OR RECORDS OF RESEARCHES — IN THE AAGEAN SEA. By PrRoFessor FE. FORBES. I. Date ... ... -o «. May 29th, 1841. Locality ... ... ... Nousa Bay, Paros. Distance from shore... Within the Bay. Depth ... ... ... ... 65 to 6 fathoms. Ground... ... ... ... Mud and sandy mud. Pinna squamosa ... .. ose 0 1 Modiola tulipa... ... os. 1 0 In sandy mud, Pecten polymorphus 4 6' » hyalinus ‘ 1 0 Nucula margaritacea ... ... ... 0 40' In dark mud. Cytherea chione ... ... ... «.. 0 1 an venetiana 200 1 3-5! a5 apicalis .. 1 2-12! DISTRIBUTION IN DEPTH. 149 ee Species. Number of living specimens. Number of dead _ Artemis lincta Tapes virginea Venus verrucosa Tellina donacina > balaustina... Syndosmya alba Lucina lactea... ... » squamosa ... » rotundata ... Cardium rusticum ... a exiguum ... Cardita sulcata obs sts Patella scutellaris ... ... Calyptreea Sinensis 000 G00 Bulla hydatis ... Turritella 3 plicata... Trochus canaliculatus .. Cerithium lima... ... SX us vulgatum Murex fistulosus : Aplysia depilans ... ... ... Ostrea plicatula ... ... ... Date Locality Depth ... Distance from shore ... Ground... — oo ok — OrrFmwmwooooo coowoooooococo ire COCO wWrRH rb — a. Sept. 14th, 1842 Gulf of Smyrna. 26 fathoms. Two miles and a half, Fine brown mud. specimens. Observations. _ A strong valve. Washed in from, shore. In dark mud. Full grown, adhering to each other. Small. New. New. New. New. Avicula Tarentina... ... 3 3 Saxicava arctica ... 2. os 4 0 III. ~ ate August 5th, 1841. Locality Off northern extremity of Paros. Depth . .. .» 40 fathoms. Lae Tigunnes coe Sion 5. Three miles and a half. Ground... area Pecten pusio ... ... 5 4 »> oOpercularis... 0 iL Nucula margaritacea 0 ah Cytherea apicalis ... 0 | 1! Cardita squamosa ... 1 1 Cardium papillosum 0 2 Fusus fasciolaroides 1 0 Murex brandaris 0 =) Vermetus gigas 0 1 + corneus... ... 3 0 Trochus exiguus ... .,. 8 2 Turbo rugosus... ... 1 0 Pleurobranchus sordidus 1 0 Doris tenerrina ... ... se 2 Fr) gracilis .. 000, ) 050 a 2 = coccinea is 1 Ascidium, four species bic Aplidium, two species 150 — MANUAL OF THE MOLLUSCA. IV. Sept. 16th, 1841. Off Ananas Rocks. 105 fathoms. Nullipore. From Rocks three miles, from Milo ten milsa. DDALOM peschiteces less Mocalitiva yess) ee IDXSOUIEL o60 | Goo ca 406 Grounds.) <2. a. Distance from shore ... Number Number Species. of living of dead Observations. specimens. | specimens. Terebratula vitrea ... ... ... ... 0 2! Dead and worn. Megerlia truncata... ... 30 100-20' Of all ages. Argiope decollata ... ... .. 100 400-6’ Of all ages. i seminulum ... ... ... 18 10-8' Morrisia anomioides ... ... ... 1 0 Adhering to T. vitrea. New. Craniaringens ... ... 0 6' Lima elongata 0 5! New. Pecten concentricus 0 12 New. » fenestratus... 0 Ws New. Spondylus Gussoni... 1 WW Arca lactea , 1 ie 3, scabra 0 a Neera cuspidata 0 1! » attenuata 0 j 1’ New. Fusus echinatus 0 2 Pleurotoma crispata 0 2 Hitherto known only fossil. on Fae A oe 0 2 New. abyssicola .. 0 4 New Mitra ‘philippiana Sue 0 4 New. Cerithium lima 0 8 Trochus tinei .. 0 6 35 exiguus .. 1 9 Turbo sanguineus ... 0 24 Hitherto known only. fossil in the Medi- terranean basin. Rissoa reticulata 4 ll 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 Vv Cleodora pyramjdata 0 3 Criseis clava ... ... 0 7 » Spinifera ... 0 10 Mi: Date >... sa. .-. «. Nov. 25th, 18412 Locality... S. extremity of Gulf of Macri. Depths.) ae. 230 fathoms. Distuiiee froma shore. Ground... ... Terebratula vitrea ... ... .0. a Syndosmya profundissima 500 Arca imbricata Dentalium quinquangulare .. Hyalea gibbosa ... ... ... Cleodora pyramidata Criseis spinifera ... ooorrce 9! 3! ]’ 0 1 8 5 One mile (shore steep). Fine yellowish mud. 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. 3. 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. Cypreea 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 bivalvesabound and form the prey of Buccinum, 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 coyer the bottom with living verdure, on which many of the carnivorous mollusks feed, while some, like Ovulum and Purpura, browse on the flexible Gorgonice. To this zone belong the oyster-banks of our seas, and the pearl- -fisheries of the south ; it is richer than any other in animal life, and affords uae most highly coloured shells. Some of the littoral shells, like Purpura lapillus and Littorina rudis, have no free-swimming larval condition, but commre 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 Nuilipore, 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 Pissurella, Hmarginula, 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 Nudllipore 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, Necra, Cryptodon, Yoldia, Dentalium, and Scissurella. In the mud brought up from deep water may be often found the shells of Pteropoda, and other mollusca which live at the surface of the sea. In the Aigean 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. Bivyalve shells, like the Solens, and the DISTRIBUTION IN DEPTH - 153 rare Panopea 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, (Fotbes.) Living sheils. Living. Dead. Fathoms, | Murex vaginatus......... 150 Cerithium metula .occssccesceeeee 20—150 | Fusus muricatus ......... 80—95 150 Margarita Cinervead ..essssssseseeeeee 10130 | Nassaintermedia....... os 45=—185 Dentalium entale ....s::.ssecce0es ; 200 | Cerithium lima...... Raabe 8-80 140 Limea sarsii............ ASBDO= IORG0E : 120 | Chemnitzia fasciata ... 110—150 Leda pygraea .......... Mecuan'sa ie a 200 | Eulima distorta ...... ne 69—140 Yoldrs tiriicttula) ‘ojstciavecss ee. Me 120 | Scalaria helleriica ...... 110 MMCHS IEGTENT Eis suk s snc csee sees »» 40100 | Rissoa reticulata......... 55 185 Cryptodon flexuosus ..........0. & 200 | Trochus exasperatus ... 10—105 165 Scissurella plicata ...... 70O—150 Of the Cape. (Belcher:) Acmea unicolor ......... 60—105 150 Buccitium ? clathratum ....... aes 136 | Dentaliam quinquangulare 150—230 Volutilithes abyssicola ..........6 132 | Bulla utriculus ......... es 40—140 Pectunculus Belcheri...........5.05 120 | Spondylus Gussonii ... 105 Pecten Hoskynsii .... 185—200 Eigean, (Forbes) Arca imbrivata ..........55 90-230 Living, Dead. | Nezra cuspidata ......... 12-185 Terebratula vitrea ..,.::....,. 100 250 | Thetis anatinoides ...,.. 40—150 Argiope decollata .....,...... 100 110 | Kellia abyssicola .. ..,,.. T0180 200 Craitia ringens).......4.....0.. » §0 150° Syndosmya profundissima 80—185 Preserving molluscous animals for examination. 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.(Ophiccoma) 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 retfacting their tentacles. But the bivalves (stich as Phofas) 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. H 3 154 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 bechanged. 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 Calcium 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 gradational forms between the highest cepha- lopod and the lowest vertebrate; but we can descend from the more to the less specialised forms of mollusca, which ultimately merge in one direction in such creatures as Fasciola, among entozoa; and in another direction, to forms like Vorticella, through the intermediate genera — Pedicellina, among the Bryozoa, and Perophora among the Ascidians. It is conse- quently much easier to define the higher than the lower boundaries of a great primary group. The points of analogy between the cephalopods and the vertebrates are the internal skeleton, the similarity in the form of the blood corpuscles, and in the capillary structure of the portion of the circulatory system situated between the arteries and veins. The cephalopods move partly by means of a series of long muscular arms arranged round the mouth, partly by means of fins, or flaps, attached on each side of the body, and partly by the forcible expulsion of water through a tube or siphon. Unlike most of the mollusca, they are symmetrical animals, having their right and left sides equally developed. Their shell is usually straight, or coiled in a vertical plane. The nautilus and argonaut alone (of the living tribes) have external shells ; the rest are termed ‘‘ naked cephalopods,” because the shell is internal. They have powerful jaws, acting vertically, like the 156 MANUAL OF "HE MOLLUSCA. a 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 bya 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 branchic. ORDER I.—DIBRANCHIATA, Owen. Animal swimming; naked. Head distinct. yes sessile, prominent. Mandibles horny (Pl. I., fig. 2). Arms eight or ten, provided with suckers. Body round or elongated, usually with a pair of jins; 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 ; viz., powerful arms, furnished with suckers ; the * According to the established usage, we designate that the wnder 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 the margin of each cup, the muscular fibres converge to the centre, where they leave a circular cavity, occupied by a soft carwnele, 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, like the chameleon. In fresh specimens, the sclerotic plates of the eyes have a pearly lustre; they are sometimes preserved in a fossil state. The aquiferous pores are situated on the back and sides of the head, on the arms (brachial), or at their bases (buccal pores). The mantle is usually connected with the back of the head by a broad (‘‘ 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. { 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. 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; 1t 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 fest 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. Hyes 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 ae 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 altered as to be incapable of acting as a locomotive organ. ae According to Dr. Miller, the arm is detached, after it has been — filled with semen, and is fixed on to the female. The arm, or whatever it may be that is so attached, was formerly mistaken * Denys Montfort, having represented a “ kraken octopod,” in the act of scuttling a three-master, told M. Defrance that if this were “ swallowed,” he would in his next 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. 8, Pl. J. 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, 12 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.f It is similar in form to the others, but is only seyen lines in length, and has a fiiform 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.t (K6lliker.) It would seem strange how former observers could have overlooked so marked a feature as the metamorphosed or hecto- cotylised arm of cuttle fishes. Aristotle not only gives a clear description of the peculiarity, but even shows that he was aware of the function the arm performed. Subsequent writers appear to have misunderstood Aristotle; at any rate they refer to the colourless arm as a monstrosity, or in some cases they have used it as one of the distinctive characters of a species. There are numerous instances in which the male has formed one, and the female another species in the naturalist’s catalogue. Now that the hectocotylus is known to be only a portion of the male, their relation is more clearly seen. They present an analogous phenomenon to what occurs in some species of spiders, in which _ * An, 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. Sc. 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. Semething similar also occurs in Polydesma. Madame Power appears to have made her observations on an hectocotylus when she asserted that the young argonaut has 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 Kélliker.* ‘‘ The process of yolk division is partial, and the development of the embryo takes place within a distinct germinal area, whence a distinct yolk sao 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. (KUlliker). A, Embryo two lines in diameter; m, mantle; 0, branchial processes; 5s, siphonal __ processes; a, mouth; e, eyes; 1—64, 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 aris (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 epipodiuwm; their * Entwickelungs-geschichte der Cephalopoden. Zurich, 1844. | 3 CEPHALOPODA. 161 anterior ends are continuous and attached; the posterior ends are at first free, but eventually uniting they form the funnel Ds. 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 ae from the nidimental capsule, fine layers of the shell of the young cuttle-fish m. wee have been formed; but except the nucleus, which is calcified, they are Fig. 36. 2 ae embryo horny and transparent. The lateral eee 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; vis the yolk sac; o the position of the future mouth; e the eye; 0 the gill; and m the mantle. Famity I.—ARGONAUTIDA. Dorsal arms (of the female) webbed at the extremity, secreting asymmetrical involuted shell. Third left arm in male hecto- cotylised ; deciduous, colourless, developed in a sac. Female polyandrous. Mantle supported in front by a single ridge on the funnel. . / Genus ArconauTa, Lin. Argonaut, or paper sailor. Etymology, argonautai, sailors of the ship Argo. Synonyms, ocythoé (Rafinesque). Nautilus (Aristotle and Pliny). 162 MANUAL OF THE MOLLUSCA. 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 special function is for protec- S 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 Ianthina. The argonaut sits in its boat with its siphon turned towards the keel,+ 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 like 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 funne/, 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 argonaut shell with the nucleus reversed, implying that the animal had turned quite round in its shiell, 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 Jike 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 neryous ganglia in its axis. It was the nautilus (primus) of Aristotle, who described it as floating on the surface of the sea, in fine weather, and holding out its sail-shaped arms to the breeze. It does not use its arms as sails, but it sometimes uses them as oars when it wishes to progress slowly, while floating on the surface of the sea. Distribution : 4 species of argonaut are known; they inhabit the open sea throughout the warmer parts of the world, and are most active during the night. Captain King took several from the stomach of a dolphin caught upwards of 600 leagues from land. Fossil, 2 species, Tertiary. A. 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 II].—OcToPoDpiIpZ. Arms similar, elongated, united at the base by a web. Shell represented by two short styles, encysted in the substance of the mantle. (Owen.) Octopus, Cuvier... Poulpe. Etymology, 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 yoracious; 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 MUJLLUSCA. 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 more developed than the corresponding arm on the left side, and terminates in an oval-shaped plate (Fig. 38, c),. marked with numerous trans- verse ridges, between which are pits. A muscular fold of skin passes from this plate down the dorsal margin of the arm to the web at its base; the mar- gin is rolled up, and forms a covered passage through which the spermatophore is probably transmitted tothe terminal plate. The arm is permanently at- tached, and is developed in a free state from a cyst, A. Distribution: universally Mie found on the coasts of the tem- Pearce Yaw showing cyst in place of perate and tropical zones; 46 B, Ventral side of an individual more species are known; when developed, with the Hectocotylus C. Pal they vary a length from 1 inch to more than 2 feet, according to the species. Fig. 38. Octopus carena ¢, Ver. Sub-genus. Tremoctopus (Chiaje), Pl. I., Fig. 3. Name from two large aquiferous pores (tremata) on the back of the head. * « Journal of a Voyage round the World.” The most fascinating volume of travels published since Defoe’s fiction. CEPHALOPODA. 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 awe rows; third right arm hectocotylised. Distribution, 3 species. T'. quoyanus, violaceus, and. velifer. Atlantic and Mediterranean. Pinnocrorus, D’Orb. Finned octopus. Body with lateral fins, united behind. The only known species, P. cordiformis, was discovered by MM. Quoy and Gaimard, on the coast of New Zealand; it exceeds 3 feet in length ELEDONE. (Aristotle.) Leach. Type, Ki. octopodia, L. Suckers forming a single series on each arm; length 6 to 18 inches. EH. Moschata emits a musky smell. Third right arm hectocotylised ; permanently attached ; developed free. Distribution, 2 species. Coasts of Norway, Britain, and the Mediterranean. CIRROTEUTHIS. 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. Miilleri, 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. ScaHureus. 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. Bouirana. Strp. 1868. Similar to Eledone, but more gelatinous, and with small suckers. 1 species living. SECTION B.—DECAPODA. Arms 8. Tentacles 2, elongated, cylindrical, with expanded ends. Suckers pedunculated, armed with a horny ring. Mouth surrounded by a buccal membrane, sometimes lobed and fur- nished with suckers. Hyes movable in their orbits. Body oblong or elongated, always provided with a pair of fins. Hunnel 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. The lingual dentition of the cuttle-fishes somewhat resembles that of the pterovoda. The central teeth are simple in sepia and Fig. 39. Lingual teeth of Sepia officinalis (Cocken). sepiola, tricuspid in loligo, and denticulated in eledone. The lateral teeth or uncini are three on each side, and mostly simple and claw-like. There were fifty rows of teeth in one specimen of 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 calcareous ‘‘ 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 spirultrostra 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 coastsand banks. (Owen, D’Orbigny. ) Famity II].—TEvuTHIDA. 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, Lu. vulgaris (sepia loligo, L.). Fig. 1. Pl. I., 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. ins terminal, united, rhombic. Mantle supported by a cervical ridge, and by two grooves in the base of the funnel. Suckers in two rows, with horny, dentated hoops. Tentacular club with four rows of suckers. Length (excluding tentacles) from 3 inches to 23 feet. Fourth left arm in male metamorphosed at its extremity. Steenstrup* says two species are confounded under the name of L. vulgaris. The variety occurring in the Atlantic, and not in the Mediterranean, is a distinct species (L. 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. Etymology, 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. GoNnaATUS, 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. ameena, Miller sp.) is found on the coast of Greenland. SEPIOTEUTHIS, Blainville. Synonyms, (?) Loliolus (Steenstrup); Chondrosepia (Leuckart). Type, S. sepioidea, Bl. Animal like loligo; fins lateral, as long as the body. Length from 4 inches to 3 feet. Fourth left arm hectocotylised at the apex. Distribution, 13 species. West Indies, Cape, Red Sea, Java, Australia, Mediterranean. hanes BELOTEUTHIS, Minster. Etymology, belos, a dart, and teuthis. Type, B. subcostata, Minster. Pl. II., fig. 8., Upper Lias, Wurtemberg. Pen horny, lanceolate; with a very broad shaft, pointed at each end, and small lateral wings. Distribution, 6 species described by Minster, considered varieties of one only (differing in age and sex) by M. D’Orbigny. GEOTEUTHIS, Minster. Etymology, ge, the earth (i. e. fossil), and teuthis. Synonyms, belemnosepia (Agassiz), belopeltis (YVoltz), 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, L. 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, C. scabra, Leach. Body large, ventricose ; fins small, terminal ; mantle supported in front by a branchial septum. Length two inches. Head very small. Hyes fixed. Buccal membrane large, 8-lobed.. Arms short, suckers in two rows. Tentacular clubs finned behind, cups in four rows. Funnel valved. Pen long and narrow. Distribution, 3 species. West Africa; in the open sea. This genus makes the nearest approach to the octopods. SEPIOLA. (Rondelet) Leach, 1817. Example, 8. atlantica (D’Orbigny). PI. 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. 8. 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 ceryical 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. LoLigopsis, 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. Funnel 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 teuthis. Type, C. veranu, Fér. Mantle supported in front by ridges. Funnel valveless. Ven- tral arms very long. Tentacles extremely elongated, slender, — with distant sessile cups on the peduncles, and four rows of pedunculated claws on their expanded ends. . Pen slender, slightly winged at each end. Length of the body two inches; to the tips of the arms eight inches; to the ends of the tentacles three feet. Distribution, 2 species. Atlantic, Mediterranean; on gulf- ‘weed in the open sea. HISTIOTEUTHIS, D’Orbigny. Etymology, nistion, a veil, and teuthis. Vype, 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. Mediterranean; in the open sea, ONYCHOTEUTHIS, Lichtenstein. Uncinated calamary. Hiymology, onyx, a claw, and teuthis. Type, O. banks, Leach (— bartlingi ?). Pl. I., fig. 7 and fig. 8 (pen). Synonyms, ancistroteuthis (Gray). Onychia (Lesueur). 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. banksit 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. smithu, 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 H. 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 lv2 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. in long. Pen sagittate. Two recent species, 7’. rhombus, T. elegans. Mediterranean. Loiouvs, 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. #4 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 Dostrpicus, 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 LVY.—BELEMNITIDA. Shell consisting of a pen, terminating posteriorly in a cham- bered cone, sometimes invested with a fibrous guard. The air- cells of the phragmocone are connected by a siphuncle, close to the ventral side. BELEMNITES, Lamarck. 1801. ea Hiymology, 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. II., 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 has to the chalk, and distributed over all Hurope. A few species have been found in the chalk * The termination ztes (from lithos, 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 73 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 ... ... ... .o. 2,674 Belemnitella mucronata, chalk B00 | IGGO) DCE NeaO CHALIT! Pinna, recent, from the Mediterranean ... ... ... 2,607 Trichites plottji, from the inferior oolite ... ... ... 2,670 Conus monile, recent con’ 600, ceo) ed ood foo. coo) 2S) Conus ponderosus, Miocene, Touraine ... ... .. «. 2,718 174 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 (siphuncle), like the shell of the pearly nautilus. It is exceedingly delicate, and usually owes its preservation to the infiltration of calcareous spar: specimens frequently occur in the lias, with the meniscus- shaped casts of the air-chambers loose, like a pile of watch- glasses. It is usually eccentric, its apex being nearest to the ventral side of the guard. The guard is very variable in its 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. A Section I. Aca#xi (Bronn.), without dorsal or ventral grooves. Sub-section 1. Acwarii, without lateral furrows, but often channelled at the extreme point. Type, B. acuarius. 20 species. Lias—Neocomian. Sub-section 2. Clavati, with lateral furrows. Type, B. clavatus. 3 species. Lias. Section II. Gasrrocaxt (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. Szotion III. Norocatzi (D’Orb.), with a dorsal groove, and furrowed on each side. Type, B. dilatatus. 9 species. Neocomian. The belemnites appear to have been gregarious, from the exceeding abundance of their remains in many localities) as in CEPHALOPODA. 175 some of the marlstone quarries of the central counties, and the ' has 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 haye been frequently noticed. BELEMNITELLA, D’Orb. Synonym, Actinocamax, Miller (founded on a mistake.) Type, B. mucronata, Sby. Pl. I., Fig. 6. Distribution, Europe; North America. 6 species. Upper greensand and chalk. The guard of the belemnitella has a straight fissure on the ventral! side of its alveolar border ; its surface exhibits distinct vascular impressions. The phragmocone is never preserved, but casts of the alveolus show that it was chambered, that it had © a single dorsal ridge, a ventral process passing into the fissure of the guard, and an apical nucleus. XIPHOTEUTHIS, Hux. (1864). Shell with a long phragmocone enveloped in a calcareous sheath. Fossil. ispecies. 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 MOLLUSCA. Animal provided with arms wal tentacles of nearly equal length, furnished with a double alternating series of horny hooks, from 20 to 40 pairs on each arm; mantle free all round; jins large, medio-dorsal (much larger than in Fig. 40). Fossil in the Oxford clay of Chippenham. Similar horny claws have been found in the has 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.* Famity V.—SEPIADA. Shell (cuttle-bone, or sepiostaire) calcareous ; consisting of a broad laminated plate, terminating behind in a hollow, = * 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.; c, is an ideal section of the same. Since this woodcut was executed a more complete specimen has been obtained for the British Museum ; the tentacles are not longer than the ordinary arms, owing, perhaps, to 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. SEpra (Pliny), Linnzeus. Type, 8. officinalis, L. Pl. I1., Fig. 6. Synonyms, Belosepia, Voltz. (B. sepioidea, Pl. IL., Fig. 3, mucro only.) Paloteuthis, Roem. Body oblong, with lateral fins as long as itself. Ayms with four rows of suckers, .Wantle supported by tubercles fitting into sockets on the neck and funnel. Length 3 to 28 inches. Shell as wide and long as the body; very thick in front, concave internally behind ; terminating in a prominent mucro. The thickened part is composed of numerous plates, separated by vertical fibres, which render it very light 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 14 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, 80 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. II., Fig. 3. 8. ungula occurs fossil in Texas, SPIRULIROSTRA, D’Orb. Type, 8. Bellardii (D’Orb.). Pl. II., 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 (Blainville), Deshayes. Etymology, belos, a dart, and pteron, a wing. Type, B. belemnitoides, Blainville. Pl. IL, 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 feenitae): 138 178 MANUAL OF THE MOLLUSCA. - Shell, mucro chambered and siphuncled ; without lateral va or elongated beak. seers 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. Famity VI.—SprruLipz. Shell entirely nacreous ; discoidal ; whorls separate, chambered .(polythalamous), with a ventral siphuncle. SPIRULA, Lam., 1801. Synonym, Lituus, Gray. Example, S. levis (Gray). Pl. 1., Fig. 9 Body oblong, with minute terminal fins. Mantle supported by a cervical and two ventral ridges and grooves. Arms with six rows of very minute cups. Tentacles elongated. Funnel valved. , _ Shell placed vertically in the posterior part of the body, with the involute spire towards the ventral side. The last chamber is not larger in proportion than the rest; its margin is organically connected ; it contains the ink-bag. The delicate shell of the spirula is scattered by thousands on the shores of New Zealand; it abounds on the Atlantic coasts, and a few specimens are yearly brought by the Gulf-stream, and strewed upon the shores of Devon and Cornwall. But the animal is only known by a few fragments, and one perfect specimen, obtained by Mr. Percy Earl on the coast of New Zealand. _ Distribution, 3 species. All the warmer seas. ORDER IJ.—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 nautilus 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 . é . orthoceras ._ baculites. bent on ttselfin . . ascoceras . ptychoceras. curved in. : . cyrtoceras . toxoceras. spiralin sy ; . 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.+ 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. j + A. heterophyllus, Sby., from the lias, Lyme Regis. British Museum. Only one side is represented ; the arrow indicates the dorsal saddle. oe 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 lamellze 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. j Fig. 42. Nautilus Pompilius,L. Fig. 438. Clymenia striata, Miinst., see Pl. II-, Fig. 16. Fig. 44. Hamites cylindraceus, Defr., see Fig. 65. + 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. TRL., . 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, 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. Fig. 47. Gomphoceras Fig. 48. Phragmoceras.j 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. limestene, Bolland (in the cabinet of Mr. Tennant). The dotted lines indicate the /ateral 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. J 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 aramonites 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 imner 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.} Calcareous mandibles, or rhyncholites (F'. Biguet), have been obtained from all the strata in which nauwtili 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. 49.7 * 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 1’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 Stckes, Esq. t The triyonellites have been described by Meyer as bivalve shells, cine: 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 JZ. 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 Scaphamidia. § M. D’Orbigny has manufactured two genera of calamaries out of these nautilus 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 (WN. 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. II., Fig. 11); the other, which appears to be only the lower mandible of the same species, has been described under the name of ‘‘conchorhynchus avirostris.’’* They also occur in the belemnite beds of the middle lias of Dorsetshire ; these latter are very different in form from those of nautili in the lower lias, and may probably belong to belemnites. In studying the fossil tetrabranchiata, it is necessary to take into consideration the varying circumstances under which they have been preserved. In some strata (as the lias of Watchett) the outer layer of the shell has disappeared, whilst the inner nacreous layer is preserved. More frequently only the outer layer remains ;.and in the chalk formation the whole shell has perished. In the calcareous grit of Berkshire and Wiltshire the ammonites 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, serpule, 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.{ In this state they are permeated by mineral water, which slowly deposits calcarecus spar, in crystals, on their walls; or by acidulous water, which removes every trace of the shell, leaving a cavity, which at some future time may again become filled with spar, having the form of the shell but not its structure. In some sections of orthocerata it is evident that the mud. has gained access to the air-cells; but the cham- bers are not entirely filled, because their lining membrane has contracted, leaving a space between itself and certain portions of the walls, which correspond in each chamber. The tetrabranchs could undoubtedly swim, by their respira- tory jets; but the discoidal nautili and ammonites are not well * Lepas avirostris (Schlotheim), described by Blainville as the beak of a brachiopod! + Called spondylolites by old writers. t 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. rhe 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 provided for by the increased size and strength of the siphuncle, and its increased vascularity. In endoceras we find the siphuncle thickened by internal deposits, until in some of the very cylin- drical species it forms an almost solid axis. The nucleus of the sheli is rather large in the nautili, and causes an opening to remain through the shell, until the umbilicus is filled up with a callous deposit; several fossil species have always a hole through the centre. In the ammonites, the nucleus is exceedneyy small, and the whorls compact from the first. It has been stated that the septa are formed periodically; but it must not be supposed that the shell-muscles ever become detached, or that the animal moves the distance of a chamber ~ all at once. It is most likely that the adductors grow only in front, and that a constant waste takes place behind, so that they are always moving onward, except when a new septum is to be formed; the septa indicate periodic rests. . The consideration of this fact, that the nautilus must so frequently have an air-cavity between it and its shell, is alone sufficient to convince us that the chambered cephalopods could * A nautilus pompilius (in the cabinet of Mr. Morris) weighs 1lb., and when the siphuncle is secured, it floats with a 3lb. 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 loved 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 ovaries; they occur in genera which must have produced very small eggs. CEPHALOPODA. 185 not exist in very deep water. They were probably limited to a depth of 20 or 30 fathoms at the utmost.* It is certain that the sexes were distinct in the 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 (?). Dr. Melville has made a similar suggestion with respect to the nautili; namely, that the umbilicated specimens are the males, the imperforated shells, females. Professor 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 spadiz. 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, Lituites, Phragmoceras, Gom- phoceras, and Ascoceras. Faminy I.—NAUTILIDA. Shell. Body-chamber capacious. Aperture simple. Sutures simple. Siphuncle central or internal. (Figs. 50, 51.) NAUTILUS, Breynius, 17382. 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. I1., Fig. 10. The wmbilicus is small or obsolete in the typical nautili, and the whorls enlarge rapidly. In the palzeozoic species, the whorls increase slowly, and are sometimes scarcely in contact. The last air-cell is frequently shallower in proportion than the rest. v * 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. ) { 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 y j Me yf P, SSS S 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 tentacles 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; s, portion of the shell; a, shell-muscie. The internal organs are indicated by dotted lines; 6, branchie ; h, heart and renal glands; ¢, crop; g, gizzard; J, 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).* Tnside 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 inyolute spire of the _ shell: and are thus rendered horse-shoe shaped. The siphuncle is vascular; it opens into the cavity containing the heart (peri- cardiwm), 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. al 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 Loven, 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 (1anthina). 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 operculiyerous 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 * Tdeal representation of the nautilus, when expanded, by Professor Lovén, who appears to have taken the details from M. Valenciennes’ Memoir in the Archives du Museum, vol. ii., p. 257. h, 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. Shelis ornamented with transverse ribs, mainly cretaceous ; and 3. Sériati. Shells ornamented with longitudinal strie. These are confined to the oolite in Kurope. In India a few species occur in the lower chalk. Sub-genus. Aturia (Bronn). = Megasiphonia, D’Orb. Type, N. zic-zac, Sby. Pl. II., 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. Hocune; 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 WN. dor- salis, Phil., and one other species, in which the siphuncle is nearly external. Fossil, 16 species. Upper Silurian—Carb. Lirvires, Breynius. Etymology, lituus, a trumpet. Synonyms, Hortolus, Montf. (whorls separate). _Trocholites, Conrad. Example, L. conyolvans, Schl. IL. 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. TROCHO6CERAS, 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 have been considered Lituites. MANUAL OF THE MOLLUSCA. Cot, , ep | 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. IT., Fig. 16 (Mus. Tennant). Shell discoidal; septa simple or slightly lobed; siphuncle internal. Fossil, 45 species. Upper Silurian—Mount. Limestone. North America, Kurope. . Famity Il.—ORTHOCERATIDA. 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 chevron- shaped coloured bands preserved on the orthoceras anguliferus,t 5s sufficiently prove that the shell was essentially external. ORTHOCERAS, Breyn. Etymology, orthos, straight, and ceras, a horn. Yynonyms, Cycloceras, McCoy. Gonioceras, Hall.t Conoceras, Brom. Example, O. Ludense (diagram of a longitudinal section) Hee UD, Davos 1M 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. t Zheca and Tentaculites are provisionally placed with the Pteropoda; they pro- bably 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 beén 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 Hichwald. 27 species. Lower Silurian—Trias? North America and Europe. } 1 ete << SENN, ae 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. 8. 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. 3species. 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 4.) Fig. 55. Crmoceras Bayfield, Stokes. Drummond Island. (From Mr. Stokes’ paper, Geol. Trans.) 192 MANUAL OF THE MOLLUSCA. stationed on Drummond Island. Specimens have also been brought home by the officers of many of the Arctic expeditions. But with the exception of one formerly in the possession of \ i Ti are an NR dl Wy Di 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. _ QOrthocerata with two siphuncles have been observed, but there has always appeared something doubtful about them. In the present instance, however, this structure cannot be questioned.” (J. Sowerby.) Small orthocerata of various species are frequently found in the body chamber and open siphuncle of large specimens.+ 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. Huroniu vertebralis, Stokes. afrom a specimen in the British Museum presented by Dr. Bigsby. The septa are added from Dr. Bigsby’s drawing; they were only indicated in the specimen by “ colourless lines on the brown limestone.” .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 3. ; Tt Shells of Bellerophon and Murchisonia are found under the same circumstances. CEPHALOPODA. 193 have resembled G'ontoceras, 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). Tyne, G. pyriforme, Sby., Fig. 58, and G. Bohemicum, Bar. Fig, 47. Fig. 57. Endzoceras.* Fig. 58. Gomphoceras.t} Shell, fusiform or globular, with a tapering apex; apertura contracted in the middle; siphuncle moniliform, sub-central. Distribution, 27 species. Lower Silurian—Carb. North America, Europe, Brit. Barrande figures 70 species in Vol. IT. of his ‘‘Systéme Silurien,”’ 1865, nearly all of which are believed to be new. ONCOCERAS, 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 (Steiminger species), Pl. II., Fig. 15. Shell curved, laterally compressed; aperture contracted in the middle; siphuncle, 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, McCoy. Gyroceras, D’Orbigny. | Example, C. hybridum, Volborthi, and Beaumonti (Barrande). Shell curved ; stphuncle small, internal, or sub-central. Fossil, 84 species. Lower Silurian—Carb.; North and South America and Europe. Fig. 59.* GYROCERAS, Meyer, 1829. Etymology, gyros, a circle, and ceras. Synonym, Nautiloceras, D’Orbigny. Example, G. eifeliense, D’Arch. (PI. II., Fig. 13), 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 Hurope. NotTHocERAS, Barrande, 1856. Shell nautiloid, slightly inyolute ; 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; swtwres angulated, or lobed and foliated ; siphuncle 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,t 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 cristati acquire, when adult, a process projecting from the outer margin of their shell. Certain other ammonites (the ornati, coronati, &c.) form two lateral processes before they cease to grow (PI. III., Fig. 4). 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. 1 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 witk. 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 doformed | 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 branchizw on one side. In the British Museum there are deformed specimens of A. obtusus, amaltheus, and tuberculatus. Fig. 60.t GONIATITES, De Haan. Etymology, gonia angles, (should be written gonialites ?). Synonym, aganides, D’Orbigny (not Montf— Aturia zic-zac). Examples, G. Henslowi (Pl. III., Fig. 1), G. sphericus (Figs. 60 and 46). i 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. oe CEPHALOPODA. 197 BactRITES, Sandberger (=stenoceras, D’Orbigny ?). Shell straight ; sutures lobed. Type, B. subconicus, Sbger. Distribution, 8 species. Devonian, Germany. edo YY a WW Fig. 61.* CERATITES, De Haan. Type, C. nodosus (Pl. III., Fig. 2). Shell discoidal; sutures lobed, the lobes crenulated (Fig. 61). Distribution, 29 species. Devonian—Chalk. Europe, India. M. D’Orbigny describes five shells from the gault and Upper greensand as ceratites ; but many ammonites have equally simple sutures, when young. Fig. 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. * Fio. 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 differences 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. III., Fig. 6), bisul- catus (Pl. III., Fig.-7). 2. Falciferi, L. oolites, A. serpentinus, radians, hecticus. 3. Cristati, cretaceous, A. cristatus, rostratus (Fig. 62), varians, B. Back crenated. 4. Amalthet, ool. A.amaltheus, cordatus, excavatus. . Rothomagenses, cret. A, rothomagensis, from Rothoma- gum, Rouen (Pl. ITT., Fig. 4). Or C. Back sharp. 6. Disci, oolitic, A. discus, clypeiformis, D. Back channelled. cret. A. dentatus, lautus. 7, Dentatt, Ha A. Parkinsoni, anguliferus. EK. Back squared. 8. Armati, L. ool. A. armatus, athletus, perarmatus. 9. Capricorni, L. ool. A. capricornus, planicostatus. 10. Ornati, ool. A. Duncani, spinosus (Pl. IIL, Fig. 5). fg } \ | CEPHALOPODA. 199 F. Back round, convex. 11. Heterophylli, IL. ool. A. heterophyllus (Fig. 41). 12. Ligati, cret. A. planulatus (Pl. HII., 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- CRIOCERAS, Leveille. Etymology, krios, a ram, and ceras, a horn. Synonym, Tropeeum, 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; ss, dorsal saddles; 2’ /' 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, Hallstadt (copied from Quenstedt). A, profile, showing the numerous lobes and saddles; B, suture of one side; v, dorsal saddle. 200 MANUAL OF THE MOLLUSCA. 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, incuryed. Synonym, Anisoceras, Pictet. Example, A. spinigerum (Pl. ITI., Fig. 10). Sheil 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. E’ymology, scaphe, a boat. Example, S. equalis (Pl. IIL, Fig. 9). Shell at first discoidal, with close whorls; last chamber detached and recurved. Distvibution, 19 species. Oolite—Chalk. Europe, India. HE.IcocErAs, 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’. reflecus (Quenstedt, T. 20, Fig. 16) has its apex inflected and concealed. CEPHALOPODA, 201 HAmiITES, Parkinson. Etymology, hamus, a hook, Example, H. attenuatus (PI. III., 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 | . 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. Bipuolgy. 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. Bacunites, Lamarck. Etymology, baculus, a staff. Example, B. anceps (Pl. IlI., 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, having the foot thin and vertical; they swim near the surface of the sea in a reversed position, or adhere to floating sea-weed. Fig. 66. A nucleobranch.* The gasteropods are nearly all ursymmetrical, 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 yivi- ‘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. Carinaria cymbium, Desh. = C. cristata, L. sp. (after Blainville), Medi-= terranean. p, proboscis; t, tentacles ; 6, branchie; s, shell; f, foot; d, disk. +t M. Lovén believes that the embryo shell of the nudibranchs falls off at the time they acquire a locomotive foot. GASTEROPODA. 203 (pulmonifera), the other water (branchifera). The water-breathers have at first a small nautiloid shell, capable of concealing them entirely, and closed by an operculum. Instead of creeping, they swim with a pair of ciliated fins springing from the sides of the } 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 eal): 3 scarcely any difference between the young of Fig. 67. eolis and aplysia, or buccinum 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. * Figo. 67. Fry of Holis (from Alder and Hancock). 0, the operculum; the original is not larger than the letter o. i 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 sia of the gasteropods is usually spiral, and univalve ; ; more rarely tubular, or conical, and in one genus it is multivalve. The following are its principal modifications :— A. Regularly spiral, a. elongated or turreted; terebra, turritella. b. cylindrical; megaspira, pupa. c. Short; buccinwm. d. globular; natica, helia. e. depressed ; solarium. j. discoidal ; planorbis. . convolute; 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. XII., Fig. 1. . many-whorled ; Helix polygyrata. Pl. XII., Fig. 2 . ear-shaped; haliotis. B. Irregularly spiral; siliquaria, vermetus. C. Tubular; dentalium. 1), Shield-shaped ; umbrella, parmophorus. i. Boat-shaped; navicella. F. Conical or limpet-shaped ; patella. G. Multivalve and imbricated ; chiton. The only symmetrical shells are those of carinaria, aa dentalium, and the limpets.* Nearly all the spiral shells are dextral, or right-handed; a few are constantly sinistral, like clausilia ; reversed varieties of many shells, both dextral and sinistral, have been met with. The cavity of the shell is a single conical or spiral chamber; no gasteropod has a multilocular shell like the nautilus, but spurious chambers are formed by particular species, such as Lriton 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 ; 3s eS es * 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.”—Phil. Trans, Lond. 1838. Pt. 2, p. 351. GASTEROPODA. 206 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 uwmbilicated (e.g. solarium). The perforation may be a mere chink, or fissure (rima), as in lacuna; or it may be filled up by a shelly deposit, as in many naticas. In other shells, like the triton, the whorls are closely coiled, leaving only a pillar of shell, or columella, in the centre: such shells are said to be imperforate. ee ee outer lip 4 of the aperture. / _.....__.-.../ 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 poimts 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 (stghonostomata); this canal, or siphon, 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 scisswrella, the tube of typhis, the perforation in fissurella, and the series of holes in haliotis. The margin of the aperture is termed the peristome; sometimes it is continuous (cyclostoma), or becomes continuous in the adult (carocoila) ; 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 (labrum), 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 to the aperture are spiral or longitudinal, and others which coincide with the lines of growth are ‘‘ transverse,” as regards the whorls; but stripes of colour extending from the apex across the whorls are often described as ‘‘longitudinal” or ‘“‘radiating,” with respect to the entire shell. Shells which are always concealed by the mantle are colourless, like limaw and parmophorus ; and those which are covered by the | | : GASTEROPODA. 907 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, an 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 aemeel 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 cthers only close the entrance partially, and in many genera, especially those with large apertures (e.g. dolium, cassidaria, harpa, navicella), it is quite rudimentary or obsolete. Fig. 70. Fig. 72. Fig. 74. 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. VIII., Fig. 25*). Multispiral, or many-whorled (Fig. 72), as in Pope. 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 aaa 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 liable to be modified in accordance with the wants and habits of the creatures. The instruments with which animals obtain their food are of all others most subject to these adaptive modifications, and can never form the basis of a philosophical system. { * Ofversiot af Kongl. 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. Tzenioglossa, teeth 3. 1.3; Littoriua, 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. t 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. Somes 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. Cuyier’s classification was Fig. 75. the first that possessed much merit, and several of his orders have since been united with advantage. System of Cuvier. System now adopted. Class. GASTEROPODA, Order 1. Pectinibranchiata - a ae Ord. Prosobranchiata, M. Edw. 4, Tubulibranchiata 5. Pulmonata Ord. Pulmonifera. 6. Tectibranchiata 7. Inferobranchiata i Ord. Opisthobranchiata, M. Edw. 8. Nudibranchiata. Class. HETEROPODA. Ord. Nucleobranchiata, Bl. 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. Sees distinct. (M. Edwards.) Section A. SrIPHONOSTOMATA. 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 back, Species all marine. FAMILY J.—StTrompip#. 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. AN 2 ZF XS LS "SWRA WE, FE REMY SS Fig. 76.¥ Stromsus, L. Stromb. Htymology, strombos, a top. Type, 8. pugilis (Pl. IV., Fig. 1). Shell rather ventricose, tubercuiar or spiny; spire short; aperture long, with a short canal above and truncated below; outer lip expanded, lobed above, and sinuated near the notch of * Fig. 76. Strombus auris- Diane, L. (after Quoy and Gaimard), Amboyna. 7p, pro- boscis, between the eye-pedicels ; f, foot, folded up; 0, operculum; m, border of the mantle; s, respiratory siphon. GASTEROPODA. pd; | the anterior canal. Lingual teeth (S. floridus) 7 cusped ; uncini, 1 tri-dentate, 2, 3 claw-shaped, simple (Fig. 77).* Fig. 77. Strombus. (Wilton). Strombus (floridus) is described by Lovén as having 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. fissurellus, 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. Hxample, S. Bartonensis. Pl. DY; Pie. 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. Litymology, pteron, a wing, and ceras, a horn. Type ek. Vamibis. Plo 1 V 3: Big.) 33 Shell like strombus when young ; outer lip of the adult pro- duced into several lang claws, one of them close to the spire, and forming a posterior canal. Distribution, 12 species. India, China. _ *® The lingua] dentition of strombus resembles that of @porrhazs, and is unlike that of the whelks; but it is more probable that aporrhats is the representative of strombus than that it is very closely allied. 912 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. SrRAPHS, 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. ocene—. London, Paris. The animal of terebellum has an operculum like strombus ; its eye-pedicels are simple, without tentacles. (Adams.) In one fossil species, 7’. fusiforme, there is a short posterior canal, as in rostellaria. FAmIty I1.—MuvRiIcipz. 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; wuncini, single. Predatory on other mollusca. The two species belong- ing to the genus Cheletropis, Forbes —Sinusigera, D’Orbigny, GASTEROPODA, 9138 aro now known to have no affinity with the Atlantidx, but to be the larva form of species belonging to the Muricide. | | Fig. 78. Murex tenuispina. (Wilton.) MovrREX (Pliny), L. Types, M. palma-rose, Pl. IV., Fig. 10. M. tenuispina, Pl. iV., Fig. 9. M. haustellum, Pl. IV., Fig. 8. M. radix, olnnatus. ’ Shell ornamented with three or more continuous longitudinal varices ; aperture rounded ; beak often very long; canal partly closed ; operculum concentric, nucleus sup-apical (Pl. LV., Fig. 10); lingual dentition (M. erinaceus), teeth single, three srested ; uncini single, curved. For dentition of M. 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, &ce. A few of the species usually referred to this genus belong to pisania and trophon. The murices appear to form only one-third of a whorl annually, ending in a varix; some species form intermediate varices of less extent. M. erinaceus, a very abundant species on the coasts of the channel, is called ‘‘ sting-winkle” by fisher- men, who say it makes round holes in the other shell-fish with its beak. (See p. 21.) The ancients obtained their purple dye from species of murex ; the small shells wexe bruised in mortars, the animals of the larger ones taken out. (F. Col.) Heaps of broken shells of the WM. 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., Fre. 11. Shell like murex; but having tubular spines between the varices, of which the last is open, and occupied by the excurrent canal. Distribution, 9 species. Mediterranean, West Africa, Cape, India, Western America. ~—d0 fathoms. Fossil, 8 species. Hocene—. London, Paris. PISANIA, Bivon, 1832. Etymology, a native of (the coast near) Pisa, in Tuscany. Synonyms, Pollia, Enzina, and Huthria (Gray). Types, P. maculosa. Pl. 1V., Fig. 14 (Hnzina), zonati. Pl. 5 Ae tea 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 stele. murex, and ricinula. Distribution, about 120 species. West Indies, Africa, India, Philippines, South Seas, Western America. Fossil, Pspecies. Hocene—Britain, France, &c. RANELLA, Lam. Frog-shell. Synonym, Apollon (Montfort and Gray). Types, R. granifera, PI. IV., Fig. 12. R. 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. Jiange, low-water to 20 fathoms. Fossil, 23 species. Hocene—. Triton, 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 GASTBROPODA. 915 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, 4% (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 t1.rd 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. Htymology, fasciola, a band. Pea talina, Pl. Vi, Fie» 1 ee ") Shell fusiform, elongated ; whorls |‘ iy, m i round or angular; canal open; Aw columellar lip tortuous, with several Nal yl! ; oblique folds. Operculum claw- shaped. +. gigantea of the South Seas attains a length of nearly two Fig. 81. Fe ae feet. The teoth of Fasciolaria re- semble those of Fusus Islandicus. In Buccinwm undatum, the _ median tooth has fiye, or rarely six denticles ; and Mr. Wilton 916 MANUAL OF THE MOLLUSCA. has observed that B. limbosum, ¢ has the teeth seven cusped, while in the females they are six cusped. Distribution, 108 species. West Indies, Mediterranean, 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, Africa, 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. 6. 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. DIBAPHUS, 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, Thria (trichos), hair, and tropis, keel. Type, T. borealis, Pl. VI., Fig. 8. (=? Admete, Phil., no operculum). * Cancellaria and trichotropis form a small naturalfamily connected with cerithiade and strombide. GASTEROPODA. S14 Shell thin, umbilicated ; spirally furrowed; the ridges with epidermal fringes; columella obliquely truncated ; eae lamellar, nucleus external. Animal with a short broad head; tentacles distant, with eyes on the middle; proboscis long, retractile. Lingual nition similar to velutina; teeth single, hamate, denticulated ; wncini 3: 1 denticulate, 2 and 3 simple (Fig. 82). ——_ Fig. 82. Trichotropis borealis. (Warrington). Lovén places Trichotropis 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 having 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. Pyruna, 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. re 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. Beers (= Pyrella, Sw. P. spirillus.) Rapana, Schum. P. bezoar, shell pocicated Operculum lamellar, nucleus external. This appears to be a Purpura. Myristica. Sw. P. melongena. Pl. V., Fig. 7. Operculum pointed, curved. 218 MANUAL OF THE MOLLUSCA. Fusus, Lam. Spindle-shell. Synonyms, Colus, Humph. Leiostoma (bulbiformis). Sw. Strepsidura, Sw. Type, F. colus. Pl. Y., 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—Hocene—. Britain, &e. Sub-genera, Trophon, Montfort. F. magellanicus, Pl. IV., Fig. 16. 38 species. Antarctic and Northern seas. British coast. 5—70 fathoms. Jossi/, 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. 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. Jossitl, 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. Fusus (chrysodomus) antiquus, called the red-whelk on the coasts of the Channel, and ‘‘ buckie”’ in Scotland, is extensively dredged for the markets, beimg more esteemed than the buccinuwm. 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 (I. contrarius, Sby.) is found in the Mediterranean, and on the coast of Spain; it abounds in the pliocene tertiary (crag) of Essex. The fusus deformis, a similar species, found off Spitzbergen, is always reversed. Famity III.—Buccrnipz. Shell notched in front; or with the canal abruptly reflected, producing a kind of varix on the front of the shell. 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, 186 fathoms, off Cape). South Australia. Fossil, 130 species, including Pisania, &c. Gault ?—Miocene— Britain, France, ees 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. Hach capsule contains five or six young, which, when hatched, are like Fig. 83, 0: a represents the inner side of a single capsule, showing the round hole from which the fry have escaped. Sub-genus, Cominella, Gray. Hz. 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 6 represents the length of the young shell, Ey 920 MANUAL OF THE MOLLUSCA. Type, P. plumbea. PI. 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’Orpigny. Leiodomus, Sw. Bullia, Gray. Types, A. gigantea, Lea. Buc. levigatum. 3B. semiplicata, PlOY., Big. 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. iy 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 (/epralia). 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. Distribution, 109 species, mostly tropical. Mediterranean (1 species). India, China, Western America. Fossil, 24 species. Eocene—. Britain, France, Chili. as Fee GASTEROPODA. 221 Esurna, Lamarck. Ivory-shell. Etymology, ebur, ivory. Synonym, Latrunculus, Gray. Type, HK. spirata. Pl. V., Fig. 11. Shell umbilicated when young; inner lip callous, spreading and covering 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. W. reticulata, L., is common on the English shores at low water, and is called the dog-whelk by fishermen. Distribution, 210 species. Low water—50 fathoms. World- wide. Arctic, Tropical, and Antarctic Seas. Fossil, 19 species. Eocene—. Britain, &c. North America. Sub-genus, Cyllene, Gray. ©. 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. PuHos, 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. Hehe MANUAL OF THE MOLLUSCA. ? RrneicuLa, 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 purpure produce a fluid which gives a dull crimson dye; it may be obtained by pressing on the operculum. P. lapilius 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. \ recip te R. antipathum. Founded on a s:ocies of Purpura? ee eee rr hr hh 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. fypetsicula, Pl. VI., Pig. 5. (Thyreus, Phil.) Shell very small, limpet-like; with a large aperture, channelled in front, and a minute, lateral spire. Lingual dentition peculiar ; teeth single, hooked, denticulated ; uncini, 3; 1 four-cusped, 2, 3, elongated, three-spined. Distribution, 1 species. Sicily, adhering to corals. Closely allied to purpura madreporarum, Sby. Chinese Sea. RICINULA, Lam. Etymology, diminutive of ricinus, the (fruit of the) castor-oil plant. j } Example, R. arachnoides. Pl. VI., Fig. 9 (= murex ricinus, L.). Shell thick, tuberculated, or spiny; aperture contracted by callous projections on the lips. Operculum as in purpura. Distribution, 34 species. India, China, Philippines, Australia, Pacific. Fossil, 3 species. Miocene—. France. PLANAXIS, Lam. Type, P. sulcata. 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. Pl. VI., Fig. 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 Littorinidee. Maaiuus, Montfort, 1810. Synonyms, Campulote, Guettard, 1759. Leptoconchus, Riippell. Type, M. antiquus. PI. V., Figs. 19, 20. Shell, when young, spiral, ie 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 in Fig. 85. The spiny buccal plates of Cassis have been mistaken by Gray and Adams for the teeth, which Fig. 84. Opere. i : of Cassis. in this genus, andalsoin Triton, 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. inner edge (Fig. 84). Lingual teeth 3, 1, 3, as 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. Oniscia, Sowerby. itymology, oniscus, a wood-louse. Synonym, Morum, Bolten. Type, O. oniscus; O. cancellata. Pl. VIL, Fig. 16. 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 ventricose ; canal produced, rather bent. No operculum. Distribution, 6 species. Mediterranean. Fossil, 10 species, Hocene—. Britain, France, &o, BACHYBATHRON, Gaskoin. Shell small, oblong, striated with lines of growth; spire small, depressed, with channelled suture; aperture with callous denticulated lips, ike Cyprea, Distribution, 3 species. Fig. 86. Dolium perdiz. (Original). Douium, Lam. The Tun. Type, D. palea. Pl. VIL, Fig. 12. Shell ventricose, spirally furrowed; spire small; aperture very large; outer lip crenated. No operculum. Teeth 8, 1, 3. Fig. 86. The genus Macgillivrayia, formerly assigned to the Atlantidz, 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. Fig. 87.* 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. MHarp-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 columba, 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, 206 species. Sub-tropical. ‘West Indies, Medi- terranean, India, Gallapagos, California. Small, prettily- * D. perdiz, L. species. 4 natural size (after Quoy). Vanicoro, Pacific. The } roboscis is exserted, and the siphon recurved over the front of the shell. GASTEROPODA. 297 marked shells; living in shallow water, on sandy flats, or congregating about stones. (Adams.) Fossil, 8 species. Tertiary. (The British species are pisaniw.) Sub-genus, Columbellina, D’Orbigny. 4 species. Cretaceous, France, India. Oriva, 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 obliguely; body-whorl furrowed near the base. No operculum in the typical species. Animal with a very large foot, in which the shell is half immersed; mantle lobes large, meeting over the back of the shell, and giving off filaments which lie in the suture and furrow. The eyes are placed near the tips of the tentacles. The 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, ancilla, 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, Ause tralia, Pacific. Fossil, 21 species. Hocene—. Britain, France, &c. Famity TVY.—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. Gills 2. Lingual teeth (uncini ?) in pairs, Fig. 88.* elongate, subulate, or hastate. Conus, L. Cone-shell Types, C. marmoreus, Pl. VII., Fig. 1. C. geographicus, antediluyvianus, &c. Sheli conical, tapering regularly ; spire short, many-whorled ; columella smooth, truncated in front; outer lip notched at the suture; operculum pointed, nucleus apical. Distribution, 371 species. All tropical seas. Fossil, 84 species. Chalk—. Britain, France, India, Java, &c. The cones range northward as far as the Mediterranean, and southward to the Cape; but are most abundant and varied in equatorial seas. They inhabit fissures and holes of rocks, and the warm and shallow pools inside coral-reefs, ranging from low water to 30 and 40 fathoms; they move slowly, and some- times (C. aulicus) bite when handled; they are all predatory. | (Adams.) Sub-genus Conorbis, Sw. C. dormitor, Pl. VII., Fig. 2. EKocene—. Britain, France. PLEUROTOMA, Lam. Etymology, pleura, the side, and toma, a notch. Synonym, Turris, Humphrey. Popes. se. Babylonica, Pl VL ies 2. ceed &e. Shell fusiform, spire elevated ; onal long and straight ; outer lip with a deep slit near the suture. Operculum pointed, nucleus apical. Distribution, 480 species. World-wide. Greenland, Britain, 17; Mediterranean, 19; Africa, 15; Red Sea and India, 6; China, 90; Australia, 15; Pacific, 0? West America, 52; West ———) * Fig. 88. Lingual teeth of Bela turricula (after Lovén). GASTEROPODA. 229 Indies and Brazil, 20. The typical species about 20 (China, 16; West America, 4). Low water to 100 fathoms. Fossil, 878 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. C. mitra, Pl. VII., Fig. 4. Tomella, Sw., canal long; inner lip callous near suture. T, lineata. 2 Clionella, Gray. C. sinuata, Born species. (= P. buccinoides), freshwaters, Africa. Mangelia, Leach (not Reeve). Apertural slit at the suture; no operculum, M. teeniata, Pl. VIL, Fig. 5. Greenland, Britain, Mediterranean. Bela, Leach. Operculum nucleus apical. B. turricula, Pl. VIL., Fig. 6. Defrancia, Millet,* no operculum. OD, linearis, Pl. VIL, Fie, 7. # 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. IL. 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 50 species of this pretty little genus were discovered by Mr. Cuming in the Philippine Islands. Famity V.—VoLvurTip”. _ 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. S. Hanley, Defrancia is synonymous with Mangelia. 230 MANUAL OF THE MOLLUSCA. on the tentacles, or near their base. Lingual ribbon linear; rachis, toothed ; pleurw, unarmed. Fig. 89.* Votuta. L. Volute. Type, V. musica, Pl. VII., Fig. 9. Synonyms, Cymbiola, Harpula, Sw. Volutella, D’Orbigny. Scapha, &c., Gray. Shell yentricose, 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 hebrea fill the nuclei of their spires with solid shell. V. brasiliana forms nidamental capsules 3 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, &c. Sub-genera, Volutilithes, Sw. Spire pointed, many-whorled, columella plaits indistinct. V. spinosus, Pl. VII., Fig. 10. Living, 1 species (V. abyssicola), dredged at 132 fathoms; off the Cape. (Adams.) Fossil, Eocene. Britain, Paris. Scaphetla, Sw. Fusiform, smooth. Example, V. magellanica. * Fig. 89. V. undulata, Lam. } Australia, (From Quoy and Gaimard.) GASTEROPODA. 231 Fossil, V. Lamberti, Crag, Suffolk. Melo, Brod. Large, oval; spire short. Type, M. diadema, Pl. VII., Fig. 11. New Guinea, 8 species, Cympa, Broderip. Boat-shell. Synonym, Yetus (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 ovo-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. 13. M. vulpecula Fig. 14. Shell fusiform, thick; spire elevated, acute; aperture small, notched in front; columella obliquely plaited ; operculum very small. The animal has a very long proboscis; it emits a purple liquid, having a nauseous odour, when irritated. The eyes are placed on the tentacles, or at their base. 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. MM. 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. VIL., Fig. 16. Cylindra, Schum. (Mitrella, Sw.) Shell olive-shaped. C. crenulata, Pl. VII., Fig. 16. 232 MANUAL OF THE MOLLUSCA. VOLVARIA, Lam. Etymology, vowa, a wrapper. Type, V. bulloides, Pl. VII., Fig. 17. Shell cylindrical, conyolute : 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. VIL, 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 cypreea. . Distribution, 189 species. ‘Tropical, West Indies, Brazil, Mediterranean (1 small species), West Africa, China, Australia. Fossil, 30 species. Eocene—. France, &c. Sub-genus, Hyalina, Schum. Outer lip scarcely thickened. Type, voluta pallida, Montfort, West Indies. & FamiIty VI.—Cypraipm. Cowries. Shell convolute, enamelled; spire concealed ; aperture narrow, channelled at each end ; ee lip (of adult) thickened, inflected. No operculum. Animal with a broad foot, truncated in front ; mantle sscbyadlenel on each side, forming lobes, which meet over the back of the shell; these lobes are usually ornamented with tentacular fila- ments; eyes on the middle of the tentacles or near their base; branchial plume single. Lingual ribbon long, partly contained in the visceral cavity; rachis 1 toothed; uncini 8. 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 TS near shore, feeding on zoophytes. Cyprama, L. Cowry. Etymology, Cypris, a name of Venus. Types, C. tigris, C. mauritiana Pl. VII., Fig. 20. oe = GASTEROPODA. 233° Shell ventricose, convolute, 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 uncint similar). Bip 8 The young shell has a thin and fe : sharp outer lip, a prominent spire, a 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, & line of paler colour, which indicates young.* where the mantle lobes met. Cypreea annulus is used by the Asiatic Islanders to adorn their Fig. 93. dress, to weight their fishing-nets, and for barter. 771 -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 Hastern 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 movye- 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. le chocra: OCyprovula, Gray. C. Capensis, PIS VALS ies 2 Apertural plaits continued regularly over the margin of the canal. LIuponia, Gray. OC. algoénsis, Pl. VII., Fig. 22. Inner lip irregularly plaited in front. Trivia, Gray. CO. europea, Pl. VII., Fig. 23; Fig. 98, and 15, B. Small shells with stris extending over the back. (Uncint: 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. 234 MANUAL OF THE MOLLUSCA. Distribution, 30 species. Greenland, Britain, West Indies, Cape, Australia, Pacific, West America. ERATO, Risso. Htymology, Erato, the muse of loye-songs and mimicry. Type, K. 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). OvuLum, Lam. Etymology, diminutive of ovwm, an egg. Synonym, Amphiceras, Gronoy. Types, O. Ovum, Pl. VII., Fig. 25. O. gibbosa and verrucosa. Shell like cyprea ; mner lip smooth. Distribution, 36 species. Warm seas. West Indies, Britain, Mediterranean, China, West America. Fossil, 11 species. ocene—. 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 gorgonice, &c., on which it feeds. C. patula inhabits the south coast of Britain, it is very thin, and has a sharp outer lip. Calpurnus, Montfort (name) = Ovyulum verrucosum. Volva (Fleming) = Ovulum patulum (Calpurna, Leach). Radius (Montfort) Schum. — Ovulum volva SEcTIoN B. HotostomaATA. Sea-Snails. Shell spiral or limpet-shaped; rarely tubular or multivalve: margin of the aperture entire; operculum, horny or ome usually spiral. Animal with a short non-retractile muzzle ; respiratory siphon wanting, or formed by a lobe developed from the neck (Fig. 68), gills pectinated or plume-like, placed obliquely across the back, or attached to the right side of the neck; neck and sides fre- quently ornamented with lappets and tentacular filaments. Marine or fresh-water. Mostly phytophagous.* * These “sections” are not very satisfactory, but they are better than any others yet proposed, and they are convenient on account of the great extent of the order proso-branchiata. Natica and scalaria have a retractile proboscis. Pirena has a notched aperture, and aporrhais, a canal. GASTEROPODA. 9395 Faminy I.—NATICIDA. Shell globular, few-whorled ; spire, small, obtuse; aperture semi-lunar; lip acute; pillar often callous. Fig. 94. Natica monilifera (Wilton). Anim with a long retractile proboscis ; lingual ribbon linear ; rachis 1 toothed; wnceini 3 (as in Fig. 94); foot very large;. mautle-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. VIIL., 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, Tdi, Australia, China, Ermey West Indies. Fossil, 260 species. Devonian, South America, North America, Europe, India. Sub-genera. Naticopsis, M‘Coy, N. Phillipsii. Shell imper- forate; imner lip yery 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. 98. Lunatia, Gray. N. Ampullaria. Perforation simple; epider- mis dull, olivaceous. Northern seas. Globulus, J. Sby. (Ampulina, Deshayes not Bl.) N. Sigaretina. Pl. VIIL., 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. Naticella, 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. 237) and Lossarus (p. 253), and appears to form with them a little group nearly related to Lacuna (p. 255). SIGARETUS (Adans.), Lamarck. Synonyms, Cryptostoma, Bl. Stomatia, Browne. Type, S. haliotoides. Pl. VIII., Fig. 4. Shell striated ; ear-shaped ; spire minute: aperture very wide, oblique (not pearly) ; operculum minute, horny, sub-spiral. The flat species are entirely concealed by the mantle when living; the convex shells only partially, and they have a yellowish epidermis. The anterior foot lobe (mentum) is enor- mously developed. Distribution, 31 species. West Indies, India, China, Peru. Fossil, 10 species. Eocene—. Britain, France, South America. Sub-genus. Naticina, Gray. N. papilla, Pl. VIII, Fig. 3. Shell ventricose, thin, perforated. West Indies, Red Sea, China, North Australia, Tasmania. Hocene, Paris. GASTEROPODA. 237 LAMELLARIA, Montagu. Etymology, lamella, a thin plate. Synonyms, Marsenia, Leach. Coriocella, BI. 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. Pliocene—. 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. Hiymology, velutinus, velvety (from vellus, a fleece). Type, V. levigata. Pl. VIII., Fig. 7. SOR 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 tne 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. 15, 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). V. otis. Shell minute, ear-shaped. Animal with a simple mantle, and very short tentacles. West and south-west British coast ; inhabiting chinks of rocks, between tide-marks. (Forbes. ) Velutina inhabits the laminarian zone, and ranges to 40 fathoms. V. levigata 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, caleareous; spire small; aperture large. FAmMILty IJ.—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 family, is opistho- branchiate. PYRAMIDELLA, Lam. Etymology, diminutive of pyramis, a pyramid. Synonyms, Obeliscus. Humphrey. (P. dolabrata. Pl. VIII, 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 pyramidelle 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 as appertaining to past ages than the present epoch.”—orves, GASTEROPODA. 239 Distribution, 111 species. West Indies, Mauritius, Australia. Fossil, 12 species. Chalk—. France, Britain. OposToMIA, Fleming, 1824. Etymology, odous, a tooth, and>stoma, mouth. Type, O. plicata. Pl. VIIT., Fig. 12. Shell subulate or ovate, 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. Hulimelia, Forbes. EH. 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. 940 MANUAL OF THE MOLLUSCA. EULIMA, Risso, 1826. Etymology, eulimia, ravenous Banece Synonym, Pasithea, Lea. Type, Ki. polita. Pl. VIIL., Fig. 14. Shell small, white, and polished; slender, elongated with numerous level whorls; obscurely marked on one side by a series of periodic mouths, which form prominent ribs internally ; apex acute; aperture oval, pointed above; outer lip thickened internally ; inner lip reflected over the pillar; operculum horny, sub-spiral. Animal tentacles subulate, close, with the eyes immersed at their posterior bases; proboscis long, retractile; foot truncated in front, mentum bilobed; operculum lobe winged on each side; branchial plume single; mantle with a rudimentary siphonal fold. The eulimee 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. Chemnitzia. Acuis, Lovén. Elymology, A, without, kleis, a projection. Synonym, Alvania, Leach (not Risso). Type, A. supranitida. Wood. A. ascaris, Turt. Pl. IX., 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). StyLopryemMA, 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. LEvucoTInA, Adams. Shell like last, but with last whorl ventricose; with minute dots. STILIFER, Brod. Exampie, S. 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. LoxonEMA, Phillips. Etymology, lowos, 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 simple, effuse M 242 MANUAL OF THE MOLLUSOCA. ‘below; outer lip thin, inner lip wanting, columella callous, slightly tortuous. Type, M. arculatus, Schlotheim species. Devonian. Hifel. Distribution, 1 species (M. Japonicus), Korea Straits. Fossil, 12 species. Devonian— Carboniferous. Britain, Belgium. Famity IJ].—CERITHIADA. 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 incurvyed 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. VIII., Fig. 16.* Distribution, 186 species. World-wide, the typical species tropical. Norway, Britain, Mediterranean, West Indies, India, Australia, China, Pacific, Gallapagos. Fossil, 460 species.. Trias—. Britain, France, United States, &c. i Sub-genera. Rhinoclavis, Sw. OC. vertagus. Canal long, bent abruptly ; operculum, sub-spiral. Bittiwm, Leach. C. reticulatum, Pl. VIII., Fig. 17. Small northern species, ranging from low water to 80 fathoms. Triforis, Deshayes. ©. perversum, Pl. VIII., Fig. 18. 30 species. Norway—Austvralia. Fossil, Hocene—. Britain, France. Shell sinistral; anterior and posterior canals tubular. The third canal is only accidentally present, forming part of a ~ Varlx. Cerithiopsis, Forbes. OC. tuberculare, Britain. GASTEROPODA. _ 243 Shell like bittiwm ; proboscis retractile ; oper euiar pointed, nucleus apical. Femes 4—40 fathoms. PoTAMIDES, Brongniart. Fresh-water Cerites. Etymology, potamos, a river, and ides, patronymic termination. Type, P. Lamarcku, Brong.- (= Cerit. tuberculatum, Brard.) Example, P. mixtus. Pl. VIII., Fig. 19. Synonyms, Tympanotomus, Klein, ©. fuscatum, Africa. Pirenella, Risso, C. mammillatum, Pl. VIII, Shell like cerithium, but without varices in the very numerous typical fossil species; epi- //\ dermisthick, olivebrown; operculumorbicular, many-whorled. Distribution, 41 species. California, Africa, India. In the mud of the Indus they are mixed with species of ampullaria, venus, purpura, ostrea, &. (Major W. H. Baker.) Fossil (species included with cerithiwm), Eocene—. Europe. Sub-genera, Cerithidea, Sw., C. decollata, Pl. VIII., Fig. 24. Aperture rounded; lip 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. VILL. Wig. 21. Shell pyramidal; columella with a prominent fold, more or less continuous towards the apex; and a second, less Heine. on the basal front of the whorls (as in nerinea (Fig. 98). India, North Australia. I’. telescopiwm 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 ‘st aight, often tubular; outer lip expanded. India, North Australia, * C. obtusa, Lam. sp. copied from Adams. M 2 Fig. 97. Cerithidea,* 944 MANUAL OF THE MOLLUSCA. Cerith. radulum and granulatum of the West African rivers approach very near the fossil potamides, but they have numerous varices. Lampania, Gray (batillaria, Cantor). Cerith. zonale. Pl. Ville ies 23; Shell without varices, canal straight. Chusan. The fossil potamides decussatus, Brug., of the Paris bain, resembles this section, and retains its spiral red bands. NeErinZA, 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 most abundant, and attain the largest size to the 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. f 3. Trochalia (Sharpe), columella perforated, with 74, one fold; outer wall simple, or thickened, or with one Gy, fold; folds simple. JJ 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. = Se P FASTIGIELLA, Reeve. Type, F'. carinata, Reeve. Shelé like turritella; aperture with a short canal in front (Cuming Museum, and British Museum). Fossil, Eocene. Paris (Cerithium rugosum, Lam.). AporRHAIS, Aldrovandus. Etymology, aporrhais (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. 945 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 3, 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. Aporrhais 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-pelcant, 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, S. straminea, Pl. IYV., Fig. 6. Shell turreted ; whorls angular; aperture truncated in front ; columella very oblique; outer lip 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 (Kiener.) Strutholaria. Distribution, 5 species. Australia and New Zealand, where alone it occurs sub-fossil. Famity [V.—MELANIADA. Shell spiral, turreted ; with a thick, dark epidermis ; aperture often channeled, or notched in front; outer lip acute ; operculum horny, spiral. The spire is often extensively eroded by the acidity of the water in which the animals live. 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). Type, 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. VIII., Fig. 25.* Distribution, 861 species. South Europe, India, Philippines, Pacific Islands. Distinct groups in the southern States of North America. GASTEROPODA. 247 Fossil, 25 species. Wealden—. Hurope (v. 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. V. 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, (Io, Lea. Glottella, Gray.) M. fluviatilis. Pl. VITI,, 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. Ammnicola, G. and H. A.isogona. Pl. IX., 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. ~ Litymology, palus, a marsh, and domus, home. Synonyms, Tanalia, Gray. Hemimitra, Sw. Type, P. aculeatus, Gm. species. Pl. [X., 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, hke paludina. * This is a good section of melania, but Mr. Gray’s type does not well represent it, being more like a prena in the form of its aperture. 24§ MANUAL OF THE MOLLUSCA. MELANopPSIS, 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 lp callous; operculum sub-spiral. Distribution, 21 species. Spain, Asia Minor, New Zealand. Fossil, 25 species. Eocene—. Hurope. Sub-genus. Pirena, Lam, (faunus, Montfort) P. atra. Pl. VIII., Fig. 31. Spire elongated, many-whorled ; outer lip of Fig. 102. Pirena atra. (Wilton,) the adult produced. Teeth 3. 1. 3, asin Fig. 102. Distribution, 4 species? South Africa, Madagascar, Ceylon, Philippines. FAMILY V.—TURRITELLIDA. 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. TX., 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. GASTERGPODA. 249 Sub-genera. Proto, Defr., P. cathedralis, Pl. IX., Fig. 3, aperture truncated below. Mesalia, Gray, M. sulcata (var.), Pl. [X., Fig. 2. Greenland —South Africa. fossil, Eocene. Britain, France. Cacum, Fleming. Synonyms, Corniculina, Minster. Brochus, Bronn. Odonti- dium, Phil. d 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 mner broad and serrulated. Distribution, Britain, 11 species, 10 fathoms. Mediterranean. Fossil, 4 species. Hocene—. Britain, Castelarquato. Vermetvs, 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 prowth; tube repeatedly partitioned off; aperture round; operculum circular, concave externally. Distribution, 81 species. Portugal, Mediterranean, Africa, India. Fossil, 12 species. Neocomian—. Britain, France, &c. 2 Sub-genus. Spiroglyphus, Daud. 8. 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. Ktymology, siliqua, a pod. Typo, S, anguina, Pl. [X., Fig. 8. Shell tubular; spiral at first, irregular afterwards; tube with a continuous longitudinal shit. Distribution, 8 species. Mediterranean, North Australia. Found in sponges. Fossil, 10 species. Hocene—. France, &c. iad N » 850 MANUAL OF THE MOLLUSCA. ScALARIA, Lam. Wentle-trap. Etymology, scalaris, like a ladder. Type, 8. pretiosa, Pl. [X., Fig. 9. (= T. scalaris, L.) Shell mostly pure white and lustrous; turreted; many- whorled; whorls round, sometimes separate, ornamented with 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. FamiIty VI.—LiItTtTorinipA. 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. Hiymology, littoralis, belonging to the sea-shore. Type, Li. littorea, Pl. [X., Fig. 10. Shell turbinated, thick, pointed, few-whorled; | aperture rounded, outer lp acute, columella rather =) ' flattened, imperforate, operculum pauci-spiral, Fig. LI” 103. Lingual teeth hooked and trilobed; uncini Fig 103. hooked and dentated (Fig. 104). Distribution, 131 species. The periwinkles are found on the sea-shore 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. Wire Fig. 104, Littorina littorea. (Warington.) The common species (LZ. littorea) is oviparous ; it inhabits the lowest zones of sea-weed between tide-marks. An allied species 7, rostrum or muzzle. &, buccal mass. g, Nervous ganglia (reproductive orifice, on the right side). S, Salivary gland. @, cesophagus, Z, lingual coil. m, shell-miuscle, é, branchia or gill, c, heart. n, aortas e, stomach, J, liver. A, biliary canal, f, intestine, a, anus, 0, ovary. d, oviduct. u, uterus. o', ovarian orifice. z, renal organ. y, mucus gland, Fig. 105. Littorina littorals 9 + (after Sotileyet), Animal removed from its shell; branchial cavity and back laid open. (Z. rudis) frequents a higher region, where it is scarcely reached hy the tide; itis viviparous, and the young have a hard shell 252 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 _adyance alternately. The periwinkle and trochus are the food of the thrush, in the Hebrides, during winter. The lingual canal of the periwinkle passes from the back of the mouth under the 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- whot1led. * JT. Fig. 105 is shown the manner in which a gasteropod may be !aid out for 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, GASTEROPODA, 258 Distribution, Philippines, West America. Fossarus (Adans.), Philippi. F. sulcatus, Pl. TX., 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. [X., 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-oyal. 1 species, Japanese seas. SoLARIuM, Lam. Stair-case shell. Htymology, solarium, a dial. Synonyms, architectoma, Bolten. Philippia, Gray. Helico- eryptus, D’Orbigny ? Type, S. perspectivum, Pl. IX., Fig. 15. Shell orbicular, depressed; umbilicus wide and deep; aper- ture rhombic; peristome thin; operculum horny, sub-spiral. The spiral edges of the whorls, seen in the umbilicus, have been fancifully compared to a winding stair-case. Distribution, 25 species. Tropical seas.’ Mediterranean, Hast Africa, India, China, Japan, Australia, Pacific, West America. Fossil, 56 species. Hocene—. Britain, &e. 26 other species (oolites—chalk) are provisionally referred to this genus; the cretaceous species are nacreous (v. trochus). Sub-genera. Torinia, Gray. T. cylindracea, oper- culum conical, multi-spiral, with projecting edges, Fig. 107. Living, New Ireland. uf Fossil, Hocene. Britain, Paris. Bifrontia, Desh. (Omalaxis, Desh.) S. bifrons, discoidal, the last whorl disengaged. 1 recent ‘ species. Madeira. Fig. 107. Fossil, 6 species. Eocene. Paris, Britain. 2 Orbis, Lea. Discoidal, whorls quadrate. Fossii, Hocene. America. Discohelia (calculiformis) Dunker, 1851. Las, Gottingen. This name was proposed for the depressed Huomphali of the Lower Oolites, of which there are several species in Normandy and England. * Operculum of S. patulum, Lam. 2, from Deshayes. 954 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 have occurred. Philippia (lutea) Gray, has a multi-spiral operculum, and the animal is like J'rochus. (Philippi.) Paludestrina (lapidum) D’Orbigny part. Fresh waters of South America. Shell conic, few-whorled, epidermis green ; aperture oblique, peristome abruptly reflected; opereulum claw-like. The typical species appear to be Melaniade, but some small shells like Hydrobia have been included in the genus. PHorvs, Montfort. Carrier-shell. Etymology, phoreus, a carrier. Synonyms, Onustus, Humph., Xenophorus, Fischer. Examples, P. conchyliophorus, Born. P. corrugatus, Pl. X., Fig. 1. Shell trochiform, concave beneath; whorls flat, with foliaceous or stellated margins, to which shells, A stones, &c., are usually affixed; aperture very J oblique, not pearly; outer lp thin, much produced F 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.) Animel with an elongated (non-retractile?) proboscis; ten= tacles long and slender, with sessile eyes at their outer bases; sides plain ; foot narrow, elongated behind.—Adams. Related to scalaria 2 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; . 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 ?—Hocene—. Britain and France. GASTEROPODA. 956 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 fiat- 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, 8 simple. Spawn (ootheca) vermiform, thick, semi-circular. Range, low water—é0 fathoms. Distribution, 16 species. Northcrn shores, Norway, Britain, Spain. Fossil, 1 species. Glacial beds, Scotland. Liriopa, Rang. Etymology, litos, simple, ope, aperture. Type, Li. bombyx (Pl. TX., Fig. 24). Shell minute, pointed; aperture slightly notched in front ; outer lip simple, thin ; inner lp 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. IX., Fig. 17). Synonym, Cingula, Flem. Shell minute, white or horny; conical, pointed, many-whorled; smooth, ribbed, or cancellated; aperture rounded; peristome entire, continuous; outer lip slightly expanded and thickened ; operculum sub-spiral. The animal has long, slender tentacles, with eyes on small prominences near their outer bases; the foot is pointed behind ; the operculigerous lobe has a wing-like process and a filament (cirrus) on each side. Lingual teeth single, sub-quadrate, hcoked, 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: us: 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. LRissoa 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 ulvee (Pl. [X., Fig. 18). Distribution, 50 species. Lossil, 10 species. Wealden—. Britain, &c. Syncera, Gray (Assiminea, Leach). 8. 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. delte (Pl. [X., Fig. 21.) - Aperture contracted; peristome entire; operculum pauci-spiral. Jossil, Eocene. Isle of Wight. Jeffreysia, Alder (—Rissoélla, Gray, MS.), J. diaphana. Sheil 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 Linneeus. Synonym, Delphinoidea, Brown. Type, S. planorbis (Pl. [X., 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 corallina officinalis. Distribution, ? species. Northern seas, Norway, and Britain. S. cornuella, Straits of Korea (Adams). P TRUNOATELLA, Risso. Looping-snail. Type, T. truncatula (Pl. [X., Fig. 25). (Mus., Hanley ) GASTEROPODA. 257 She mnute, 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 truncatellce 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.) ? LITHOGLYPHUS, Megerle. Type, Li. fuscus (Pl. [X., Fig. 22). Shell naticoid, often eroded; whorls few, smooth; aperture large, entire; peristome continuous, outer lne sharp, inner lip callous; umbilicus rimate; epidermis olivaceous; operculum pauci-spiral. Distribution, 5 species. Europe and Oregon. Famity VII.—PALUDINIDA. Shell conical or globular, witha thick, olive-green epidermis ; aperture rounded; peristome continuous, entire; operculum horny or shelly, normally concentric. Ammal 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 arespiratory 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. 3B. tentaculata’ (Pl. IX., Fig. 27). Shell small; operculum shelly. Animal oviparous; with only one neck-lappet, on the right side. The bithynia oviposit on stones and aquatic plants; the female lays from 30 to 70 eggs in a band of three rows, cleaning the surface as she proceeds; the young are hatched in three or four weeks, and attain their full growth in the second year. (Bouchard.) AMPULLARIA, Lam, Apple-snail, or idol-shell. Hiymology, ampulla, a globular flask. Example, A. globosa (Pl. [X., Fig. 30). Synonym, Pachylabra, Sw. Shell globular, with a small spire, and a large ventricose body- whorl; peristome thickened and slightly reflected ; operculum shelly. Animal with a long incurrent siphon, formed by the left neck- lappet; left gill developed, but much smaller than the right ;t+ muzzle produced into two long tentacular processes; tentacles * Fig. 109. Ampullaria 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 exlfibit it. It would be very desirable to examine the amp. cornu-arietis, in which, probably, the gills are symmetrical, as in the cephalopods, 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, aud 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, 1386 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. tiny) h \ (hie Fig. 162. A. decollata, *° ; dorsal valve with the animal, from a specimen dredged by Professor Forbes in the Aigean. The oral aperture is seen in the centre of the disk. a= eS Animal with oral arms, folded into two or four lobes, united by membrane, forming a brachial disk fringed with long cirri; mantle extending to the margins of the valves, closely adherent. Distribution, 5 species. North Britain, Madeira, Canaries, Mediterranean. 380—106 fathoms. Fussil, 19 species. Oolte—. Europe. Fig. 163. Z. radians. Fig. 164. T. Mediterraneum.* : THECIDIUM, Defrance. Etymology, Thekidion, a small pouch. Type, T. radians, Pl. XV., Fig. 11. Shell small, thick, punctate, attached by the beak; hinze- * Dorsal valve with the animal, magnified. Coll. Davidson. 870 MANUAL OF TITE MOLLUSCA. area (h) flat; deltidium (d) triangular, indistinct; dorsal valve (Fig. 163) rounded, depressed; interior with a broad granulated margin; cardinal process prominent, between the dental sockets ; oral processes united, forming a bridge over the small and deep visceral cavity; disk grooved for the reception of the loop, the grooves separated by branches from a central septum; loop often un- 4w\ symmetrical, lobed, and united more (J/\ or less intimately with the sides of the grooves; ventral valve (Fig. 165) deeply excavated, hinge-teeth pro- minent; cavities for the adductor (a) and pedicle muscles (p) small ; ‘ry disk occupied by two large smooth impressions of the cardinal muscles, bordered by a vascular line. Fig. 165. T.radians. 4, Animal (Fig. 164) with elongated oral arms, folded on themselves and fringed with long curi; mantle extending to the margin of the valves and closely ad- herent: epidermis distinct. T. radians is the only unattached species, it is supposed to be fixed by a pedicle when young. (D’Orbigny.) p Dorsal valve. Fig. 166. Profile.* a, adductor; c, crura; /, loop: J, cardinal process; p, hinge-plate; s, dorsal septum ; v S$, ventral septum; ¢, dental sockets. T. hieroglyphicum, Pl. XV., Fig. 12, has a very complicated * Tho loop (which was discovered by Professor King) has a distinct suture in the BEACHIOPODA. 371 interior; whilst in several others there are but two brachial lobes. The Liassic species form the subject of a monograph by M. Eudes Deslongchamps; they are often minute, and attached in numbers to sea-urchins, corals, and terebratulee. Distribution, 1 species. Mediterranean. Fossil, 34. species. Trias—. Europe. ? STRINGOCEPHALUS, Defrance. Etymology, Strinx (stringos), an owl, cephale, the head.* Type, S. Burtini, Pl. XV., Fig. 13. Figs. 166, 167. Devonian, ‘Europe. Shell punctate; sub-orbicular, with a prominent beak; ventral valve with a longitudinal septum (vs) in the middle; hinge- area distinct ; foramen large and angular in the young shell, gradually surrounded by the deltidium, and rendered small and oval in the adult; deltidium composed of three elements ; teeth prominent; dorsal valve depressed, cardinal process (j) very promi- Fig. 167.4 nent, sometimes touching the opposite valve, its extremity forked to receive the ventral septum (vs); hinge-plate (p) sup- porting @ shelly loop, after the manner of Argiope. FAmIty II.—SPIRIFERIDZ. Shell farnished internally with two calcareous spiral processes (apophyses) directed outwards towards the sides of the shell, and destined for the support of the oral arms, which must have been fixed immovably; the spiral lamellze are sometimes spinulose, indicating the existence of rigid cirri, especially on the front of the whorls; yalves articulated by teeth and sockets. SPIRIFERA, Sowerby. Type, 8. striata, Sby., Fig. 168. Synonyms, Trigonotreta. Kénig. Choristites, Fischer. Del- thyris, Dalman. Martinia, &c., M‘Coy. middle; the dotted lines proceeding from its inner edge are added from a drawing by M. Suess, and represent what he regards as shelly processes for supporting a mein- branous disk. They may be portions of spirals, whose outer whorls are confluent. * Internal casts of Productus giganteus are called “ owl-heads” by quarrymen in the North of Eng and. (Sowerby.) + Fig. 167. Young shell, magnified four diameters; h, hinge area; 6, deltidium; p, pseudo-deltidium. 372 MANUAL OF THE MOLLUSCA. Shell impunctate,* transversely oval er elongated, tri-lobed, beaked, bi-convex, with a dorsal ridge and ventral furrow ; hinge-line wide and straight; area moderate, striated across; foramen angular, open in the young, afterwards progressively Dorsal valve. Fig. 168. Ventral valve. closed; ventral valve with prominent hinge-teeth, and a central muscular scar,. consisting of the single adductor flanked by two cardinal impressions ; dersal valve with a small cardinal process, a divided hinge-plate, and two conical spires directed outwards and nearly filling the cavity of the shell; crura united by an oral loop. The shell and spires are sometimes silicified in lime- stone, and may be developed by means of acid. In S. mosquensis the dental plates are prolonged nearly to the front of the ventral valve. Distribution, 220 species. Lower Silurian—Trias. Arctic America—Chili, Falkland Islands, Europe, China, Thibet, Australia, Tasmania. In China these and. other fossils are used as medicine. Sub-genera. Spiriferina, D’Orbigny. S. Walcotti, Pl. XV., Fig. 14. Shell punctate, external surface spinulose ; foramen covered by a pseudo-deltidium ; interior of ventral valve with a prominent septum, rising from the adductor scar. Distribution, 29 species. Carb.—Lower Oolites. Britain, France, Germany, South America. Cyrtia, Dalman. (C. exporrecta, Pl. XV., Fig. 15. Shell impunctate, pyramidal, beak prominent, area equiangular, deltidium with a small tubular foramen. Fossil, 10 species. Silurian—Trias. Europe. In C. buchii, heteroclyta, calceola, &c., the shell is punctate. Suessia (imbricata), Eudes Deslongchamps, 1855. (Dedicated to M. Suess). Shell like Spirifera ; texture fibrous; hinge area wide as the shell; foramen deltoid; large valve with two cardinal septa, and a prominent central septum, supporting a little plate ; small valve with a tri-lobed cardinal process, and * Professor King attributes this to metamorphism; S. Demarlzi, Bouch., from the Devonian limestone, is punctate. (Carpenter. ) BRACHIOPODA, Bs) a broad 4-partite hinge-plate, with processes from the outer angles of the dental sockets; crura of the spires united by a transverse band supportiny a small process. ossil, 2 species. Upper Lias, Normandy. ATHYRIS, M‘Coy. Litymelogy, a, without, thuris, a door* (i.e. deltidium). Synonyms, Spirigera, D’Orbigny. OCleiothyris, King (not Phil.), Types, A. concentrica, Buch. / unas Fig. 186. Produetus? Leonhardi, 2.* spiral cavities, once occupied by the arms, and now filled with spar, may be seen in specimens with both valves, by holding them tothe light. M. Suess, of Vienna, states that he has found traces of very slender spiral lamellee occupying the furrows. This curious little shell most resembles the Triassic Leptena dubia (Productus), Minster (= Crania Murchisoni, Klipst!). DavipsontiA, Bouchard. Dedicated to the author of the Monograph of British Fossil Brachiopoda. Type, D. Verneuili, Bouchard. Fig. 187. Devonian, Eifel. Dorsal valve. Fig. 187. Ventral valve.2 Shell solid, attached by outer surface of the ventral valve to rocks, shells, and corals; valves plain, articulated ; ventral valve with a wide area (h); foramen angular, covered by a convex deltidium (d); disk occupied by two conical elevations, obscurely grooved by a spiral furrow of 5-6 volutions; dorsal valve with two shallow lateral cavities; vascular impressions consisting of two principal sub-marginal trunks, in each valve, * A, translucent specimen; B, interior of dorsal valve. af E ‘ BRACHIOPODA, | 383 with diverging branches; cardinal and adductor impressions distinct. The furrowed cones undoubtedly indicate the existence of spiral arms, similar to those of Atrypa (Fig. 180), but desti- tute of calcified supports. The upper valve sometimes exhibits markings derived from the surface on which the shell has grown. The mantle-lobes seem to have continued depositing shell until the internal cavity was reduced to the smallest possible limit. Fossil, 3 species. Devonian—Trias. Dorsal valve Fig. 188. Ventral valve, CALCEOLA, Lamarck. Htymology, calceola, a slipper. Type, C. sandalina, Pl. XV., Fig. 26. Fig. 188. Shell thick, triangular ; valves plain, not articulated ; ventral valve pyramidal; area large, flat, triangular, with an obscure central line; hinge-line straight, crenulated, dorsal valve flat, semicircular, with a narrow area (), a small cardinal process (7), and two lateral groups of small apophysary (?) mules (0) ; internal surface punctate-striate. Fossil, Devonian, Hifel, Britain. The supposed dechome boone species (Hypodema, D. K.) is, per- haps, related to Pileopsis. Calceola is shaped like Oyrtia, and its hinge-area resembles that of some Strophomenas. FAMILY V.—PRODUCTIDA, Shell concayo-convex, with a straight hinge-line; valves rarely articulated by teeth; closely appressed, furnished with tubular spines; ventral valve convex ; dorsal concave; internal surface dotted with conspicuous, funnel-shaped punctures; dorsal valve with a prominent cardinal process; brachial pro- cesses (?) sub-central; vascular markings lateral, broad, and simple ; adductor impressions dendritic, separated by a narrow central ridge ; ventral valve with a slightly notched hinge-line ; o84 MANUAL OF THE MOLLUSCA. adductor scar central, near the umbo; cardinal impressions lateral, striated. LN Aliph in | At AM) \ vy |i i i ly a iy s Seip NAl | A Rall. ] HN iN ee i) Ws an HOON (iw Fig. 189. Productus giganteus, 1 Carb. limestone. A, interior of dorsal valve; B, interior of ventral vaive, with the umbo removed; C, ideal section of both valves; D, hinge-line of A; 7, cardinal process; a, adductors r, cardinal muscles; 4, oral processes?; s, hollows occupied by the spiral arms; v, vascular impressions ; /, hinge-area. PRoDUCTUS, Sowerby. Types, P. giganteus, Martin. —Anomia producta, Martin. Examples, P. horridus, Pl. XV., Fig. 27. P. proboscideus, PINKY; Hig. 28: Shell free, auriculate, beak large and rounded; spines scat- tered; hinge-area in each valve linear, indistinct; no hinge- teeth ; cardinal process lobed, striated; vascular impressions simple, curved; ventral valve deep, with two rounded or sub- spiral cavities in front. These shells may have been attached by a pedicle when young, the impressions of the pedicle-muscle blending with those of the hinge-muscles (c) in the ventral valve. A few species appear to have been permanently fixed. P. striatus is irregular in its growth, elongated and tapering towards the beak, and occurs in numbers packed closely together. P. proboscideus seems to have lived habitually in cayities, or half-buried in mud, as suggested by M. D’Orbigny; its ventral valve is prolonged seyeral inches beyond the other, and has its BRACHIOPODA. 885 edges rolled together and united, forming a large permanently open tube for the brachial currents. The large spines are most usually situated on the ears of the ventral valve, and may have seryed to moor the shell; being tubular they were permanently susceptible of growth and repair. Although edentulous, the dorsal valve must have turned on its long hinge-line with as much precision as in those genera which are regularly articulated by teeth. Fossil, 81 species. Devonian—Permian. North and South America, Europe, Spitzbergen, Thibet, Australia. Exterior. Fig. 190. Interior. Sub-genus. Aulosteges, Helmersen. A. Wangenheimii, Vern., Fig. 190. Permian, Russsia; Carb. Shell like Producta; ventral valve with a large flat triangular hinge-area (i), with a narrow convex pseudo-deltidium (d) in the centre; beak a little distorted, as if attached when young; dorsal valve slightly convex near the umbo; interior as in Productus (longi-spinus). STROPHALOSIA, King. Example, 8. Cancrini, De Vern., Fig. Gite Synonym, Orthothrix, Geinitz. Shell attached by the umbo of the ventral valve; sub-quadrate; covered with long slender spines; valves arti- culated, dorsal moderately concave, ventral convex, each with a small area; fissure covered; vascular impressions conjoined, reniform. Fossil, 8 species. Devonian—Carb. Fig. 191. 8. Cancrini. Europe, Himalaya (Gezard). 3 s ’ ae oh ay ach \R\ \ os SY aiii\he\\ Va We 386 MANUAL OF THE MOLLUSCA. CHONETES, Fischer. Example, CO. striatella, Pl. XV., Fig. 29. Etymology, chone, a cup. Shell transversely oblong, with a wide and straight hinge-line; area double; valves radiately striated, articulated; hinge-margin of ventral valve with a series of tubular spines; fissure covered; interior punctate-striate; vascular impressions (v) very small. (Davidson. ) Fossil, 47 species. Silurian—Carboniferous. Europe, North America, Falkland Islands. Dorsal valve. Fig. 192. Ventral valve.* Faminy VI.—CRANIADA. Shell orbicular, calcareous, hinge-less ; attached by the umbo, or whole breadth of the ventral valve, rarely free; dorsal valve limpet-like ; interior of each valve with a broad granulated border ; disk with four large muscular impressions, and digitated Secular a impressions ; structure punctate. Animal with free spiral arms, directed towards the concavity of the dorsal valve, and supported by a nose-like prominence in © the middle of the lower valve; mantle extending to the edges of the valves, and closely adhering; its margins plain. © (Fig. 195.) CRANIA, Retzius. Etymology, kraneia, capitate. Type, Anomia craniolaris, L. Examples, O. Ignabergensis, Pl. XV., Fig. 30. C. anomala, Figs. 193—195. Synonyms, Criopus, Poli. Orbicula (anomala), Cuvier, =O. Norvegica, Lam. * Interiors of two sp. of Chonetes, from Nehou and the Eifel, after Davidson: a, adductor ; ¢, cardinals. BRACHIOPODA. } 387 Shell smooth or radiately striated ; umbo of dorsal valve sub- central ; of ventral valve sub-central, marginal, or prominent and cap-like, with an obscure triangular area traversed by a _ central line. The large muscular impressions of the attached valve are Fig. 193. Ventral valve. Fig. 194. Dorsal valve. Crania anomala, Muller. | Zetland. a, anterior adductors; a’, posterior adductors; c, posterior adjustors; c', cardinal muscle ; 7, 0, central and external adjustors. sometimes conyex, in other species deeply excavated; those of the upper valve are usually convex, but in C. Parisiensis the anterior (central) pair are developed as prominent diverging apophyses. In C. tripartita, Minster, the nasal process divides the fixed valve into three cells.* | C. Ignabergensis is equivalve, and either quite free or very slightly attached. C. anomala is gregarious on rocks and stones in deep water, both in the North Sea and Mediterranean (40—90 fathoms, living ; 150 fathoms, dead ; Forbes); the animal is orange-coloured, and its labial arms are thick, fringed with cirri, and disposed in a few horizontal gyrations (Fig. 195). Distribution, 5 species. Spitzbergen, Britain, Mediterranean, India, New South Wales. —150 fathoms. Fossil, 37 species. Lower Silurian—. Europe C. antiquissima, Hichw. (Pseudo-crania, M‘Coy), is free, and has the internal border of the valves smooth; the branchial impressions blend in front. Spondylobolus craniolaris, M‘Coy, is a small and obscure fossil, from the Lower Silurian shale of Builth. The upper valve appears to have been like Orania, the lower to have had a small grooved beak, with blunt, tooth-like processes at the hinge-line. * M. Quenstedt has placed the Oolitic Cranias in Siphonaria ! $2 ~ 388 MANUAL OF THE MOLLUSCA. FAMILY VII.—DIscin1pZ&. ; Shell attached by a pedicle, passing through a foramen in tho ventral valve; valves not articulated ; minutely punctate. Fig. 195. Crania.* Fig. 196. Discina.+ Animal with a highly vascular mantle, fringed with long horny setze; oral arms curved backwards, returning upon them-~ selves, and ending in small spires directed downwards, towards the ventral valve. Disctna, Lamarck. Synonyms, Orbicula, Sby. (not Cuviert). Orbiculoidea (elliptica), D’Orbigny. Schizotreta, Kutorga. Types, D. lamellosa, Pl. XV., Fig. 31. (=D. ostreoides, Lamarck.) . Shcli orbicular, horny ; upper valve limpet-like, smooth or concentrically lamellose, apex behind the centre; lower valve flat or conical, witha sunk and perforated disk on the posterior side ; interior polished; lower valve with a central prominence in front of the foramen. Animal transparent ; mantle lobes distinct all round; labial folds united, not extensile, ; alimentary canal simple, bent upon itself ventrally, and terminating between the mantle-lobes on the right side. There are four distinct adductor muscles as in * Dorsal valve, with the animal, seen by removing the mantle. + The animal as seen on the removal of part of the lower mantle-lobe ; the extremities of the labial arms are displaced forwards, in order to show their spiral terminations : y is the expanded surface of the pedicle; the mouth is concealed by the overhanging cirri. The mantle-fringe is not represented. t The Orbicula of Cuvier was the Patella anomaila, mili (= Crania), as pointed out by Dr. Fleming, in the ‘“‘ History of British Animals,” 1828.. BRACHIOPODA. 3889 ‘Orania; and three pair of adjustor muscles for keeping the valves opposed to each other. Some of these are probably inserted in the pedicle. The oral cirri are extremely tender and flexible, contrasting with th: stiff and brittle setze of the mantle, wii » Y typ yy \\ AK MES; \\ \\ Za SST \\\ = \ ——_ TO SIS YY Mi) i i] ANI Wiis at HHL i A Fig. 202. Dorsal.* Fig. 203, Ventral. Fig. 204. Ventral. Lingula anatina, Lam. (original). Syn. Patella unguis, L. (part.) aa, anterior adductors ; a', posterior adductor; p p, external adjustors ; p'p', central adjustors; r 7, anterior retractors (the anterior occlusors of Hancock); 7’r'r', posterior adjustors; c, capsule of pedicle; mm, visceral sheath; 0, cesophagus; s, stomach , 1, liver ; 1,intestine; v, vent; 0, branchial vessels ; m', mantle margin ; m, inner lamina of mantle margin retracted, showing bases oi setae; $, Sete. ing the posterior half of the shell, and surrounded by a strong muscular sheath; pedicle elongated, thick ; stomach long and straight, sustained by inflections of the visceral sheath ; intes- tine convoluted dorsally, terminating between the mantle-lobes on the right side, oral arms disposed in about six close whorls, their cavities opening into the prolongation of the visceral sheath in front of the adductors. Observations on the living lingula are much wanted; the oral arms probably extended as far as the margins of the shell ; and the pedicle, which is often nine inches long in preserved specimens, is doubtless much longer, and contractile when * In Fig. 202 a small portion of the liver and visceral sheath have been removed, to show the course of the stomach and intestine. In some specimens the whole of the vis_era, except a portion of the liver, are concealed by the ovaries. In Fig. 204 the front half of the ventral mantle-lobe is raised, to show the spiral arms; the black spot in the centre is the mouth, with its upper and lower lips, one fringed, tlre other plain. The manile-fringe has veen omitted in Figs. 202, 204. 392 MANUAL OF THE MOLLUSCA. alive. The shell is horny and flexible, and always of a greenish colour. Distribution, 16 species. India, Philippines, Moluccas, Aus- tralia, Feejees, Sandwich Islands, West America. Fossil, 91 species. Lower Silurian—. North America, Europe, Thibet. Lingule existed in the British seas as late as the period of the Coralline Crag. The recent species have been found at small - depths, and even at low water half buried in sand. L Davisit, Lower Silurian, Tremadoe, has a pedicle-groove like Obolus, Fig. 205. (Salter.) ' Fig. 205. Ventral valve. Fig. 206. Dorsal valve. . Obolus Davidsoni. (Salter.) Wenlock limestone, Dudley. A, posterior adductors; B, adjustors; C, anterior adductors. The pedicle-scar in the centre of Fig. 168 has no letter. Oxouus, Hichwald. Synonyms, Ungula, Pander; Aulonotreta, Kutorga. Etymology, obolus, a small Greek coin. Type, O. Apollinis, Eichw. Shell orbicular, caleareo-corneous, depressed, sub-equivalve, smooth; hinge-margin thickened inside, and slightly grooved in the ventral valve; posterior adductor impressions separate ; anterior pair sub-central; impressions of adjustors lateral. Fig. 205, 206. (After Davidson.) Fossil, 8 species. Lower and Upper Silurian. Sweden, Russia, England, United States. CONCHIFERA. ood CHAPTER IY. CLASS V. CONCHIFERA, LAMARCK. (Lamelli-branchiata, Blainville.) The bivalve shell-fish, or Conchifera, are familiar to every one, under the form of oysters, scallops, mussels, and cockles.* They come next to the univalves (gasteropoda) in variety and importance, and though less numerous specifically, are far more abundant individually.t The bivalves are all aquatic, and excepting a few widely-dispersed and prolific genera, are all inhabitants of the sea; they are found on every coast, and in every climate, ranging from low-water mark to a depth of more than 200 fathoms. In their native element the Oyster and Scallop lie on one side, and the lower valve is deeper and more capacious than the upper; in these the foot is wanting, or else small, and not used for locomotion. Most other bivalves live in an erect position, resting on the edges of their shells, which are of equal size. Those which move about much, like the river-mussel, maintain themselves nearly horizontally,{ and their keel-shaped foot is adapted for ploughing through sand or mud. The position of those bivalves which live half-buried in river-beds or at the bottom of the sea, is often indicated by the darker colour of the part exposed; or by deposits of tufa, or the growth of seaweed on the projecting ends of the valves. In Nucula and some others the foot is deeply cleft, and capable of expanding into a disk, like that on which the snails glide; whilsf in the mussel, pearl-oyster, and others which habitually spin a byssus, the foot is finger-like and grooved. The burrowing species have a strong and stout foot with which they bore vertically into the sea-bed, often to a depth far exceeding the length of their valves; these never volun- tarily quit their abodes, and often become buried and fossilised in them. They most usually burrow in soft ground, but also in“coarse gravel, and firm sands and clays; one small modiola makes its hole in the cellulose tunic of Ascidians, and another in floating blubber. * They are the Dithyra of Aristotle and Swainson, and constitute the second or sub-typical group in the quinary system. + It has been stated that the predatory mollusca are more numerous than the vegetable-feeders ; but it is not so with the individuals constituting the species. ¢ This is the position in which they are always figured in English books, being best suited for the comparison of one shell with another. s3 594 MANUAL OF THE MOLLUSCA. The boring shell~fish have been distinguished from the mere burrowers, perhaps without sufficient reason, for they are found in substances of every degree of hardness, from soft mud to compact limestone, and the method employed is probably the same. * | The means by which bivalves perforate stone and timber has been the subject of much inquiry, both on account of its phy- siological interest, and the desire to obtain some remedy for the injuries done to ships, and piers, and breakwaters. The ship-worm (éeredo) and some allied genera, perforate timber only ; whilst the pholas bores into a variety of materials, such as chalk, shale, clay, soft sandstone and sandy marl, and decomposing gneiss ;+ it has also been found boring in the peat of submarine forests, in wax, and in amber.t It is obvious that these substances can only be perforated alike by mechanical means; either by the foot or by the valves, or both together, as inthe burrowing shellfish. The pholas shell is rough, like a file, and sufficiently hard to abrade limestone; and the animal is able to turn from side to side, or even quite round in its cell, the interior of which is often annulated with furrows made by the spines on the front of the valves. The foot of the pholas is very large, filling the great anterior opening of the valves: that of the ship-worm is smaller, but surrounded with a thick collar, formed by the edges of the mantle, and both are armed with a strong epithelium. The foot appears to be a more efficient instrument than the shell in one respect, inasmuch as its surface may be renewed as fast as it is worn awav.§ (Han- cock. . A mechanical explanation becomes more difficult in the case of another set of shells, lithodomus, gastrochena, saxicava, and wngulina, which bore only into calcareous rocks, and attack the hardest marble, and still harder shells. (Fig. 25, p. 34). In these the valves can render no assistance, as they are smooth, and covered with epidermis; neither does the foot help, being small and finger-like, and not applied to the end of the burrow. Their power of movement also is extremely limited, their cells not being cylindrical, whilst one of them, sawicava, is fixed in * See the admirable memoir by Mr. Albany Hancock, in the An. Nat. Hist. for October, 1848. + There is a specimen from the coast of France, in the Brit. Museum. { Highgate resin, in the cabinet of Mr. Bowerbank. § The final polish to some steel goods is said to be given by the hands of work- women. In Carlisle Castle they point to the rude impress’on of a hand on the dungeon wall, as the work of Fergus M‘Ivor, in the two years of his solitary im- prisonment. CONCHIFERA. 395 its crypt by abyssus. These shell fish have been supposed to dissolve the ruck by chemical means (Deshayes), or else to wear it away with the thickened anterior margins of the mantle. (Hancock.)* The holes of the lithodomi often serve to shelter other animals after the death of the rightful owners ; species of Modiola, Arca, Venerupis, and Ooralliophaga, both recent and fossil, have been found in such situations, and mistaken for the real miners.+ The boring shell-fish have been called ‘‘ stone-eaters ”’ (lithophagi) and ‘‘ wood-eaters”’ (xylophagi), and some of them at least are obliged to swallow the material produced by their operations, although they may derive no sustenance from it. The ship-worm is often filled with pulpy, impalpable sawdust, of the colour of the timber in which it worked. (Hancock.) No shell-fish deepens or enlarges its burrow after attaining the full growth usual to its species (p. 35). The bivalves live by filtering water through their gills.t Whatever particles the current brings, whether organic or inorganic, animal or vegetable, are collected on the surface of the breathing-organ and conveyed to the mouth. In this manner they help to remove the impurities of turbid water.§ The mechanism by which this is effected may be most conye- * All attempts to detect the presence of an acid secretion have hitherto failed, as might be expected; for the hypothesis of an acid solvent supposes only a very feeble but continuous action, such as in nature always works out the greatest results in the end. See Liebig’s Organic Chemistry, and Dumas and Boussingault on the “Balance of Organic Nature.” Intimately connected with this question are several other phenomena; the removal of portions of the interior of univalves, by the animal itself, as in the genera Conus, Auricula, and Nerita (Fig. 24, p. 32); the perforation of shells by the tongues of the carnivorous gasteropods, and the formation of holes in wood and limestone by limpets. Some facts in surgery also illustrate this subject, (1) dead bone is removed when granulations grow into contact with it: (2) if a hole is bored in a bone, and an ivory peg driven into it, and covered up, so much of the peg as is embedded in the bone will be removed. (Paget.) The “absorption” of the fangs of milk-teeth, previous to shedding, is well known. In these cases the removal of the bone earth is effected without the development of an acid, or other disturbance of the neutral condition of the circulating fluid. + Fossil univalves (trochi) occupying the burrows of a pholas, were discovered by Mr. Bensted in the Kentish-rag of Maidstone. See Mantell’s Medals of Creation. M. Buvignier has found several species of Arca fossilised in the burrows of lithodomt. ft It seems scarcely necessary to remark that the bivalves do not feed upon prey caught between their valves, Microscopists are well aware that sediment taken from the alimentary canal of bivalve shellfish contains the skeletons of animalcules and minute vegetable organisms, whose geometrical forms are remarkably varied and beautiful ; they have also been obtained (in greater abundance than ordinary) from mud filling the interior of fossil oyster-shells. 9 When placed in water coloured with indigo, they will in a short time render it clear, by collecting the minute particles and condensing ‘hem into a solid form. 396 MANUAL OF THE MOLLUSCA. niently examined in a bivalye with a closed mantle, like the great Mya (Fig. 207), which lives in the mud of tidal rivers, with only the ends of its long combined siphons exposed at the surface.* The siphons can be ex- tended twice the length of the shell, or drawn completely with- in it; they are separated, in- ternally, by a thick muscular wall. The branchial siphon (s) has its orifice surrounded by a double fringe; the exhalent siphon (s') has but a single row of tentacles; these organs are very sensitive, and if rudely touched the orifices close and the siphon itself is rapidly with- drawn. Whenunmolested, acur- rent flows steadily intothe orifice of the branchial siphon, whilst another current rises up from the exhalent tube. There is no other opening in the mantle ex- cept a small slit in front (p) through which the foot is pro- truded. The body of the animal occupies the centre of the shell (6), and in front of it is the mouth (0) furnished with an upper and a lower lip, which are ff prolonged on each side into a pair of large membranous palpi (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; 0, body; c, cloaca; f, foot; g,branchize; A, 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. CONCHIFERA. 397 and to the siphonal partition. Each gill is composed of two laminze, 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 laminze 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 gill, and propel them along the grooved edge of its free margin, in the direction of the mouth; they are then received between the palpi in the form of rayelled 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 ‘fdorsalchannels” still exist,and carry out the filtered water. In some genera the gills subserve a third purpose; the oviducts open into the dorsal channels and the eggs are received into the gill-tubes and retained there until they are hatched. In the river-mussel the outer gills only receive the eggs, with which they are completely distended in the winter months (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.* 4 The valves of the Conchifera are bound together by an elastic ligament, and articulated by a hinge furnished with interlock- ing teeth. The shell is closed by powerful adductor muscles, but opens spontaneously by the action of the ligament, when the animal relaxes, and after it is dead. Kach valve 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 TITE 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 Isocardia and Diceras. In the latter case each valve is like a spiral univalve, especially those with a large aperture and small spire, such as Concholepas ; it is the left valve which resembles the ordinary univalve, the right valve being a le/t- handed spiral like the reversed gasteropods. When one valve is spiral and the other flat, as in Chama ammonia (Fig. 224), mute Fig. 208, River-mussel. (Anodon cygneus 9). * the resemblance to an operculated spiral univalve becomes very striking. The relation of the shell to the animal may be readily deter- mined, in most instances, by the direction of the 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 thickness from the centres of the closed valves.f The Conchifera are mostly equivalve, the right and left valves * The valves are forcibly opened and the foot (7) contracted; a, anterior adductor- muscle, much stretched; py, p, palpi; g, inner gills; 0, o, outer gills distended with spawn; 8, 4, a bristle passed through one of the dorsal channels. + Linneus and the naturalists of his school described the front of the shell as the 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 unterzor; 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. CONCTIFERA. 899 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 bivalves are all more or less inequilateral, the anterior Dorsal Margin. 7) _\, Anterior Posterior gSss? é 5 ie \ side. | side. Ventral margin or base. Fig. 209. Unio pictorum, L. (original), with the right valve and mantle-lobe removed ; a, a, adductor muscles; p, p, pedal muscles; z, accessory pedal muscle; u, umboj 1, ligament ; 6, branchial orifice ; v, anal opening ; ,f, foot; o, mouth; Z, palpi. being usually much shorter than the posterior side. Pectunculus is nearly equilateral, and in Giycimeris and Solemya the anterior is much longer than the posterior side. The front of the smaller Pectens is shown by the byssal notch; but in the large scallops, oysters and Spondyli, the only indication of the posi- tion of the animal is afforded by the large internal muscular impression, which is on the posterior side. The ligament is sometimes between the umbones, but is never anterior to them. The siphonal impression, inside the shell, is always posterior. Bivalves are said to be close, when the valves fit accurately, and gaping, when they cannot be completely shut. In Gastro- chena (Pl. XXIII, Fig. 15), the opening is anterior, and serves for the passage of the foot; in Mya it is posterior and siphonal; in Solen and Glycimeris both ends are open. In Bysso-arca (Pl. XVII., Fig. 13), there is a ventral opening formed by corresponding notches in the margin of the valves, which serves for the passage of the byssus; in Pecten, Avicula, and Anomia (Fig. 211, s), the byssal notch (or sinus) is confined to the right valve. The surface of bivalve shells is often ornamented with ribs which radiate from the umbones to the margin, or with con- centric ridges, which coincide with the lines of growth. Some- times the sculpturing is oblique, or wavy; in Tellina fabula it is confined to the right valve. In many species of Pholas, 400 “MANUAL OF THE MOLLUSCA. Teredo, and Cardium, the surface is divided into two areas by a transverse furrow, or by a change in the direction of the ribs. The lunule (see Fig. 14, p. 20) is an oval space in front of the beaks; it is deeply impressed in Cardium retusum, L. Astarte excavata, and the’genus Opis. Whena similar impression exists behind the beaks, it is termed the escutcheon.* The ligament of the Conchifera forms a substitute for the muscles by which the valves of the Brachiopoda are opened, It consists of two parts, the ligament properly so called, and the cartilage; they exist either combined or distinct, and some- times one is developed and not the other. The external ligament is a horny substance, similar to the epidermis which clothes the valves; it is usually attached to ridges on the posterior hinge- margins, behind the umbones, and is consequently stretched by the closing of the valves. The ligament is large in the river- mussels, and small in the Mactras and Myas, which have « large internal cartilage; in Arca and Pectunculus the ligament is spread oyer a flat, lozenge-shaped area, situated between the umbones, and furrowed with cartilage grooves. In Chama and Isocardia the ligament splits in front, and forms a spiral round each umbo. The Pholades have no hgament, but the anterior adductor is shifted to such a position on the hinge-margin that it acts as a hinge-muscle. (Pl. XXIIL., Fig. 13.) The internal ligament, or cartilage, is lodged in furrows formed by the ligamental plates, or in pits along the hinge- line; in Mya and Nucula it is contained in a spoon-shaped process of one or both valves. It is composed of elastic fibres placed perpendicularly to the surfaces between-which it is contained, and is slightly iridescent when broken; it is com- pressed by the closing of the valves, and tends forcibly to open them as soon as the pressure of the muscles is removed. The © name Amphidesma (double ligament) was given to certain — bivalves, on the supposition that the separation of the cartilage from the ligament was peculiar to them. ‘The cartilage-pit of many of the Anatinide is furnished internally with a movable ossicle. ) The ligament is frequently preserved in fossil shells, such as the great Cyprinas and Carditas of the London Clay, the Unios of the Wealden and even in some lower Silurian bivalves. All bivalves are clothed with an epidermis (v. p. 33) which is organically connected with the margin of the mantle. It is developed to a remarkable extent in Solemya and Glycimeris * Only those technical terms which are used in a peculiar sense are here referred to; fo1 the rest, any Dictionary may be consulted, especially Roberts’s “ Etymolcgical Dictionary of Geology ” published by Longman and Co. CONCHIFERA. 401 (Pl. XXII., Figs. 13, 17), and in Mya it is continued oyer the siphons and closed mantle-lobes, making the shell appear anuternal. ‘The interior of bivalves is inscribed with characters borrowed directly from the shell-fish, and affording a surer clue to its affinities than those which the exterior presents. The structure of the hinge characterises both families and genera, whilst the condition of the respiratory and locomotive organs may be to some extent inferred from the muscular markings. The margin of the shell on which the ligament and teeth are situated, is termed the hinge-line. It is very long and straight in Avicula and Arca, very short in Vulsella, and curved in most genera. The locomotive bivalves have generally the strongest hinges, but the most perfect examples are presented by Arca and Spondylus. The central teeth, those immediately beneath the wmbo, are called hinge (or cardinal) teeth; those on each side are lateral teeth. Sometimes lateral teeth are developed, and not cardinal teeth (Alasmodon ; Kellia): more frequently the hinge-teeth alone are present. In young shells the teeth are sharp and well-defined ; in aged specimens they are often thickened, or even obliterated by irregular growth (Hippopodium) or the encroachment of the hinge-line (Pectun- culus). Many of the fixed and boring shells are edentulous.* The muscular impressions are those of the adductors, the foot and byssus, the siphons, and the mantle (see pp. 19, 20). ( Pecten v 1; tus.) Right valve. a, a, adductor; p, pedal impression; m, palial line; 7, ligamental margin; c, c, cer- tilage ; e, e, anterior ears ; 0, byssal sinus. The adductor impressions are usually simple, although the * The dentition of biyalve shells may be stated thus:—cardinal teeth, 2.3 or 2— Meaning 2 in the right valve, 3 in the Jef ; lateral teeth 1—], 2-+2, or 1 anterior and 1 posterior in the right valve, 2 anterior ard 2 po:terior lateral teeth in the /ef¢ valve. 402 MANUAL OF THE MOLLUSCA. muscles themselves may be composed of two elements,* as in Cytherea chione (Fig. 14, p. 20) and the common oyster. The impression of the posterior adductor in Spondylus is double | (Pl. XVI., Fig. 15). In Pecten varius (Fig. 210, a a), large independent impressions are formed by the two portions of the adductor, and in the /eft valve there is a third impression (p) produced by the foot, which in the byssiferous pectens is a simple conical muscle with a broad base. In the left valve of Anomia there are four distinct muscular impressions (Fig. 213). Of these, the small posterior spot alone is produced by the adductor, and corresponds with the solitary Fig. 211. Right valve. Fig. 212, Fig. 213. Left valve.t impression in the right valve. The adductor itself (Fig. 212, a’) is double. The large central impression (p) is produced by the muscle of the plug (the equivalent of the byssal muscle in Pinna and Modiola). The small impression within the umbo (w) and the third impression in the disc (p’) (wanting in Placunomia) are _ caused by the retractors of the foot. The term monomyary, employed by Lamarck to distinguish the bivalves with one adductor, applies only to the Ostreide, part of the Aviculide, and to the genera Tridacna and Miilleria. The dimyary bivalves have a second adductor, near the anterior margin, which is small in Mytilus (Fig. 30), but large in Pinna. The retractor muscles of the foot (already alluded to at p. 20) have their fixed points near those of the adductors; the anterior pair are attached within the umbones (Fig. 214, wu uw), or nearer the adductor, as in Astarte and Unio (Fig. 209). The posterior pair (p’p) are often close to the adductor, and leave no separate * Compare the shell of modiola, Pl. XVII., Fig. 5, with the woodcut, Fig. 214. 1 Fig. 211. Right valve of Anomia ephippium, L. 1, ligamental process; s, sinus. Fig 213. Left valve; J, ligament pit. Fig. 212. Muscular system, from a drawing communicated by A. Hancock, Esq. 7, the foot; pl, the plug. The muscle p38 generaily described as a portion of the addyctor ; but it is certain, from a comparison of tis shell with Carolia and Placuna, that a! represents the entire adductor, and p the byssal muscle. CONCHIFERA. 403 impression. The Unionide have two additional retractors of the foot, attached laterally behind the anterior adductors; in Leda, Solenella, and a few others, this lateral attachment forms a line extending from the anterior adductor backwards into the umbonal region of the shell. (See Pl. XVII., Figs. 21, 22.) In those shellfish like Pinna and the mussel, which are per- manently moored by a strong byssus, the foot (/) serves only to mould and fix the threads of which it is formed. The fibres of the foot-muscles pass chiefly to the byssus (6), and besides these two additional muscles (pp) are developed. In Pinna, Fig. 214. Muscles of Modiola. * Modiola, and Dreissena the byssal muscles are equal to the great adductors in size. In a few rare instances the muscles are fixed to promi- nent apophyses. The falciform processes of Pholas and Teredo (Pl. XXIII., Figs. 19, 26) are developed for the attachment of the foot-muscle; the posterior muscular ridge of Diceras and Cardilia resembles a lateral tooth, and in the extimct genus Radiolites both adductors were attached to large tooth-like pro- cesses of the opercular valve; but, as a rule, the muscles deposit * Fig. 214. Muscular system of Modiola modiolus, L., from a drawing ecommuni- cated by A. Hane:ck, Esq. aa, anterior, a'a', posterior adductors ; wu and p'p’, pedai muscles ; yp, byssal muscles ; 7, foot; &, byssus; m, pallial line. 404 MANUAL OF THE MOLITUSCA. less shell than the mantle, and their impressions deepen with age. The pallial line (Fig. 214, m)1is produced by the muscular fibres of the mantle-margin; it is broken up into irregular spots in the monomyary bivalves, and in Sawxicava and Panopeu Norvegica. The siphonal impression, or pallial sinus (Fig. 14, p. 20), only exists in those shells which have retractile siphons; its depth is an index to their length. The large combined siphons of Mya (Fig. 207) are much longer than the shell; and those of some Tellinide three or four times its length, yet they are com- pletely retractile. The small siphons of Cyclas and Dreissena cause no inflection of the pallial line. The form of the sinus is characteristic of genera and species. In the wmbonal area (within the pallial line) there are some- times furrows produced by the viscera, which may be distin- guished from the muscular markings by absence of polish and outline. (See Lucina, Pl. XIX., Fig. 6.) Fossil bivalves are of constant occurrence in all sedimentary rocks; they are somewhat rare in the older formations, but increase steadily in number and variety through the secondary and tertiary strata, and attain a maximum of development in existing seas. Some families, like the Cyprinide and Lucinide are more abundant fossil than recent; whilst many genera, and one whole family (the Wippuritide), have become extinct. The determi~ nation of the affinities of fossil bivalves is often exceedingly difficult, owing to the conditions under which they occur. Sometimes they are found in pairs, filled up with hard stone; and frequently as casts, or moulds of the interior, giving no trace of the hinge, and very obscure indications of the muscular markings. Casts of single valves are more instructive, as they afford impressions of the hinge.* Another difficulty arises from the frequent destruction of the nacreous or lamellar portion of the fossil bivalves, whilst the cellular layers remain. The Aviculide of the chalk have entirely lost their pearly interiors; the Spondyli, Chamas, and Radiolites are in the same condition, their inner layers are gone and no vacancy left, the whole interior being filled with chalk. As it | is the inner layer alone which are the hinge, and alone receives the impressions of the soft parts, the true characters of | * These impressions may be conveniently moulded with gutta-percha. M. Agassiz published a set of plaster-casts of the interiors of the genera of recent shells, which, may be seen in the Brit. Museum. [MWemoire sur les moules des Mollusques, vivans et Joussiles, par L. Agassiz, Mem. Soc. Sc. Nat. Neuchatel, t. 2.] | CONCHIFERA. 405 the shells could not be determined from such specimens. Our knowledge of the extinct Radiolite is derived ftom natural inoulds of the interior, formed before the dissolution of the inner layer of shell, or from specimens in whieh this layer is replaced by spar. The necessities of geologists have compelled them to pay very minute attention to the markings in the interior of shells, to their microscopic texttire, and every other available source of comparison and distinction. It must not, however, be expected that the entire structure and affinities of molluscous animals can be predicated from the examination of an internal mould or a morsel of shell, any more than that the ferm and habits of an extinct quadruped can be inferred from a sees tooth or the fragment of a bone.* The systematic arrangement of the bivalves now employed is essentially that of Lamarck, modified, however, by many recent observations. The families follow each other according to rele- tionship, and not according to absolute rank; the Veneride are the highest organised, and from this culminating point the stream of affinities takes two courses, ohne towards the Myas, the other in the direction of the oysters; groups analogically related to the Tunicaries and Brachiopoda. SECTION A. ASIPHONIDA. a. Pallial line simple: Integro-pallialia. Fam. 1. Ostreide. 4. Arcade. 2. Aviculidee. 5. Trigoniadee. 3. Mytilide. 6. Unionidee. SECTION B. SIPHONIDA. 7. Chamide. | 114. Lucinide. 8. Hippuritide. 12. Oycladide. 9. Tridacnide. 13. Cyprinide. 10. Cardiadee. b. Pallial line sinwated : Sinu-pallialia. 14, Veneride. 18. Myacide. 15. Mactride. 19. Anatinide. 16. Tellinidee. 20. Gastrochezenidee. 17. Solenidee. - 21. Pholadide. The characters which have been most relied on for distin- * Etudes Critiques sur les Mollusques Fossiles, par L. Agassiz, Neuchatel, 1840. 406 ) MANUAL OF THE MOLLUSCA. guishing these groups and the genera of bivalves are the fol- lowing, stated nearly in the order of their value :— 1. Extent to which the mantle-lobes are united. 2. Number and position of muscular impressions. 3. Presence or absence of a pallial sinus. 4, Form of the foot. 5. Structure of the branchie. 6. Microscopic structure of the shell. (v. p. 31.) 7. Position of the ligament, internal or external. 8. Dentition of the hinge. 9, Equality or inequality of the valves. 10. Regularity or irregularity of form. 11. Habit ;—free, burrowing or fixed. 12. Medium of respiration, fresh or salt water. A few exceptions may be found, in which one or other of these characters does not possess its usual yalue.* Such in- stances serve to warn us against too implicit reliance on single characters. Groups, to be natural, must be based on the con- sideration of all these particulars—on ‘‘ the totality of the animal organisation.” (Owen.) SECTION A.—ASIPHONIDA. Animal unprovided with respiratory siphons; mantle-lobes free, or united at only one point which divides the branchial from the exhalent chamber (cloaca); pallial impression simple. Sheli usually pearly or sub-nacreous inside; cellular ex- ternally ; pallial line simple or obsolete. * 1. Cardita and Crassatella (Fam. 13) have the mantle more open, whilst in Fridina (6), and especially in Drezssena (3) it is more closed than in the most nearly allied genera. 2. Mulleria (6) and Tridacna (9) aré monomyary. 3. Leda (4) and Adacna (10) have a pallial sinus ; Anopa (16) has none. 4. The form of the foot is usually characteristic of the families; but sometimes it is adaptively modified. 5. Dzuplodonta (11) has four gills. 6. Pearly structure is variable even in species of the same genus. 7. Crassatella (13) and Semele (16} have an internal ligament; in Solenella and Isoarca (4) it is external. 8. Anodon (16), Adacna, Serripes (10), and Cryptodon (11) are edentulous. 9. Corbula (18) and Pandora (19) are more inequivalve than their allies; Chama arcinella (7) is equivalve. 10. Hinnites (1), theria (6), Myochauma and Chamostrea (19) are irregular. 11. Pecten is free, byssiferous, or fixed: Arca free or byssiferous. This chegract varies with age and locality in the same species. It does not always depend on the form of the foot, as Lithodomus and Unyulina—boring shells—have the fyot like Alytitus and Lucina. 12. Novaculina is a river Solen, and Scaphula a fresh-water Arca. CONCHIFERA. 407 Faminy I,—OsTREIDA. Shell inequivalve, slightly inequilateral, free or adherent, resting on one valve; beaks central, straight; ligament in- ternal; epidermis thin ; adductor impression single, behind the centre; pallial line obscure; hinge usually edentulous. Animal marine; mantle quite open; very slightly adherent to the edge of the shell; foot small and byssiferous, or obsolete; gills crescent-shaped, 2 on each side; adductor muscle composed ef two elements, but representing only the posterior shell-muscle of other bivalves. The union of the Ostreide and Pectinide, as proposed by the authors of the ‘‘ History of British Mollusca,” has not proved satisfactory. The genus Ostrea stands quite alone, and distinct from all the Pectinide in the structure of its gills, which are like those of Avicula, and by resting on its left valve. The shell also is more nacreous than that of the scallops OsTREA, L.—OYSTER. Synonyms, Amphidonta and Pycnodonta, Fischer. Peloris, Poli. Type, O. edulis, L. Example, O. diluviana,. Pl. XVI., Fig. 1. Shell irregular, attached by the left valve; upper valve flat or concaye, often plain; lower convex, often plaited or foliaceous, and with a prominent beak; ligamental cavity triangular or elongated; hinge toothless; structure sub- nacreous, buna aN prismatic cellular ose: between the margins of the lamine. Animal with the mantle-margin double, finely fringed; gills nearly equal, united posteriorly to each other and the mantle- lobes, forming a complete branchial chamber ; lips plain ; palpi triangular, attached ; sexes distinct.* Distribution, 70 species. Tropical and temperate seas. Norway, Black Sea, &c. Fossil, 200 species. Carb. —. United States, Europe, India. The interior of recent oyster-shells has a slightly nacreous lustre; in fossil specimens an irregular cellular structure is often very apparent on decomposed or fractured surfaces. Fossil oysters which have grown upon Ammonites, Trigonie, &c., frequently take the form of those shells. In the ‘‘cock’s-comb” oysters both valves are plaited; O. »diluviana sends out long root-like processes from its lower * The course of the alimentary canal in the common oyster is incorrectly repre- sented by Poli, and copied in the Crochard ed. of Cuvier. 408 MANUAL OF THE MOLLUSCA. valve. The ‘‘tree-oyster” (Dendrostrea, Sw.) grows on the root of the mangrove. Oyster shells become very thick with age, especially in rough water; the fossil oyster of the Tagus (0. longirostris) attains a length of two feet. The greatest enemy of oyster-banks is a sponge (Cliona), which eats into the valves, both of dead and living shells; at first only small round holes, at irregular intervals, and often disposed in regular patterns, are visible; but ultimately the shell is completely mined and falls to pieces. Natural oyster-banks usually occur in water several fathoms deep; the oysters spawn in May and June, and the fry (‘‘ spats”) are extensively collected and removed to artificial grounds, or tanks, where the water is very shallow; they are then called ‘‘ natives,” and do not attain their full growth in less than five or seven years, whilst the ‘‘ sea-oysters ” are full-grown in four yeais. Native oysters do not breed freely, — and sometimes many die in the spawning season; they are also liable to be killed by frost. The season isfrom August 4to May 12. From 20,000 to 30,000 bushels of ‘‘ natives’? and 100,000 bushels of sea-oysters are annually sent to the London market. Many ~ other species of ee are eaten in India, China, Australia, &c. ‘Green oysters” are those which © \ have fed on conferve in the tanks. \ Sub-genera. Gryphea, Lamarck. iG. incurva, Sby. (section), Fig. } 215. Free, or very slightly at- tached; left valve with a promi- nent, incuryed umbo; right valve —=S= small, concave. Sossil, 30 species. Fig. 215. Gryphea. Lias — Chalk. Europe, India. Exogyra, Sby. E. conica, Pl. XVI., Fig. 2. Shell chama- shaped, attached by the left valve; umbones sub-spiral, turned _ to the posterior side (i.e. reversed); right valve opercular. Fossil, 46 species. Lu. Oolite — Chalk. United States; Europe. | Dimya (Deshayesana), Rouault, 1859. Mém. Soc. Géol. b. ID. 471, t. 15..Fig. 3... Hocene, Paris. The figure is most like an oyster, and the ‘‘ second adductor impression,” op. account of which it is named Dimya, is rather like the small anterior scar in Pecten (Fig. 210). AwnomiA, L. } Etymology, anomios, unequal. i Example, A. Acheeus, Pl. XVI., Fig. 3. Synonyms, Fenestrella, Weiter: Goya, Humph. Aenigma Koch. Shell sub-orbicular, very variable, translucent, and slight CONCHITFERA. 409 pearly within, attached by a plug passing through a hole or _xotch in the right valve: upper valve convex, smooth, lamellar or striate1; interior with a sub-marginal cartilage-pit, and © four iuscular impressions, 3 sub-central, and one in front of the cartilage (see Fig. 213, p. 402): lower valve concave, with a deep, rounded notch in front of the cartilage process; disk with a single (adductor) impression. Animal with the mantle open, its margins with a short double fringe; lips membranous, elongated; palpi fixed, striated on both sides; gills 20n each side, united posteriorly, the outer laminee incomplete and free ; foot small, cylindrical, subsidiary to a lamellar and more or less calcified byssal plug, attached to the upper valve by three muscles; adductor muscle behind the _byssal muscles, small, composed of two elements; sexes dis- tinct ; ovary extending into the substance of the lower mantle- lobe. _ In A. pernoides, from California, there is an anterior (pedal) muscular impression in both valves. _ “There is no relationship of affinity between Anomia and Terebratula, but only a resemblance through formal analogy ; the parts which seem identical are not homologous.” (Forbes.) The Anomiz are found attached to oysters and other shells, and frequently acquire the form of the surfaces with which their growing margins are in contact. They are not edible. Distribution, 20 species. North America, Britain, Black Sea, India, Australia, West America, Icy sea. Low water — 100 fathoms. _ Fossil, 36 species. Oolite —. Chili, United States, Europe, India. _ Sub-genera. Placunomia (Cumingii), Broderip. Synonym, Pododesmus, Phil. P. macroschisma, Pl. XVI., Fig. 4... Upper valye with only two muscular impressions; the pedal scar radiately striated; the byssal plug is often fixed in the lower valve, and its muscle becomes (functionally) an adductor. Dis- tribution, 13 species. West Indies, Britain (P. patelliformis), New Zealand, California, Behring’s Sea, Ochotsk. — 60 fathoms. Limanomia (Grayana), Bouchard. Shell eared like Lima. Fossil, 4 species. Devonian; Boulonnais, China? PrLaAcunA, Solander.—Window-Shell. ‘ Etymology, plakous, a thin cake. Example, P. sella, Pl. XVI., Fig. 5 Shell suborbicular, compressed, translucent, free, resting on i T e 410 MANUAL OF THE MOLLUSCA. the right valve; hinge area narrow and obscure; cartilage supported by two diverging ridges in the right valve and cor- responding grooves in the left; muscular impressions double, the larger element round and central, the smaller distinct and crescent shaped, in front of it. The Placunee are very closely allied to Anomia; and many intermediate forms may be traced. The shell of each consists entirely of sub-nacreous, plicated laminee, peculiarly separable, and occasionally penetrated by minute tubuli. (Carpenter.) P. sella, called, from its shape, the ‘‘ saddle-oyster,” is remarkably striated. In P. placenta, Pl. XVI., Fig. 6, the anterior carti- lage ridge is only half as long as the other, which appears to be connected with the economy of the shell when young; in speci- mens 1 inch across, there is a pedal imvression below the cartilage grooves of the upper valve, and a shallow sinus in the margin of the lower valve, indicating a slight byssal attach- ment at that age. Placuna* is essentially like Anomia, having the generative system attached to the right mantle-lobe, and the ventricle exposed. The mantle-margin is cirrated, and furnished with a curtain, as in Pecten; the foot is tubular and extensile, but has no distinct muscles except the small one, whose existence in P. placenta (Pl. XVI., Fig. 6) we had predicated from examina- tion of the shell. + The small muscular impressions before and in the rear of the adductor are produced by suspensors of the gills. Distribution, 4 species. Scinde, North Australia, China. Sub-genera. Carolia, Cantraine, 1835 (after Prince Charles Bonaparte). Synonym, Hemiplacuna, G. Sby. Type, C. placu-_ noides, Pl. XVI., Fig. 7. Shell like Placuna; hinge, when | young, like Anomia, with a byssal plug passing through a | small deep sinus in front of the cartilage process, which is closed ; in theadult. Distribution, 3 species. (British Museum), Tertiary, Egypt; America ? ) Placunopsis, Morris and Lycett. P. Jurensis, Roemer. Sub- orbicular, upper valve convex, radiately striated, or taking th form of the surface to which it adheres; lower valve flat; liga mental groove sub-marginal, transverse; muscular impressio large, sub-central. fossil 4 species. Lower Oolites, Europe. Placenta, Retzius. Cartilage grooves slightly divergent, t posterior one the longer of the two; muscular impression sub- central. * Original figures and descriptions will be found in the An. Nat. Hist. 1855, p. 2 + This organ appears to represent the byssal-sheath of Anomia, rather than the fdot, as there is no other opening for the passage of a byssus. CONCHIFERA. 411 PxcTEN, O. F. Miller. Scallop. Etymoloyy, pecten, a comb. Type, P. maximus (Janira, Schum.) Synonyms, Argus, Poli. Discites, Schl. Amusium, Muhlfeldt. Shell sub-orbicular, regular, resting on the right valve, usually ornamented with radiating ribs; beaks approximate, eared; anterior ears most prominent; posterior side a little oblique ; right valve most convex, with a notch below the front ear; hinge-margins straight, united by a narrow ligament; cartilage internal, in a central pit; adductor impression double, obscure; pedal impression only in the left valve, or obsolete (Fig. 210). Animal with the mantle quite open, its margins double, the inner pendent like a curtain (m) finely fringed; at its base a row of conspicuous round black eyes (ocelli) sur- rounded by tentacular fila- ments; gills (br) exceed- ” ingly delicate, crescent- shaped, quite disconnected posteriorly, having separate pas excurrent canals; lips folia- EL Ee AEE _ceous; palpi truncated, plain outside, striated within; foot finger-like, grooved, byssiferous in the young. The Scallop (P. maximus) and ‘‘quin” (P. opercularis) are esteemed delicacies ; the latter covers extensive banks, especially on the north and west of Ireland, in 15 to 25 fathoms water. The scallop ranges from 3—40 fathoms; its bodyis bright orange, or scarlet, the mantle fawn-colour, marbled with brown; the shell is used for ‘‘ scalloping” oysters, formerly it was em- ployed as a drinking-cup, and celebrated as such in Ossian’s “‘hall of shells.” An allied species has received the name of «St. James’s shell” (P. Jacobeus); it was worn by pilgrims to the Holy Land, and became the badge of several orders of knighthood.+ Most of the Pectens spin a byssus when young, and some, like P. varius, do so habitually ; P. niveus moors itself to the fronds of the tangle (Laminaria). * The Pectens do not open so wide as here represented; their “ curtains”? remain ix. contact at one point on the posterior side, separating the branchial from the exhalent currents. + When the monks of the ninth century converted the fisherman of Gennesaret into a Spanish warrior, they assigned him the scallop-shell for his “cognizance.” (Moule’s * Feralury of Fish.’’) T 2 412 MANUAL OF THE MOLLUSCA. The Rey. D. Landsborough observed the fry of P. opercular’s, when less than the size of asixpence, swimming in a pool of sea-water left by the ebbing of the tide. ‘‘ Their motion was rapid and zig-zag; they seemed, by the sudden opening and closing of their valves, to have the power of darting like an arrow through the water. One jerk carried them some yards, and then by another sudden jerk they were off in a moment on a different tack.” The shell of Pecten and the succeeding genera consists almost exclusively of membranous laminee, coarsely or finely corru- gated. Itis composed of two very distinct layers, differing in colour (and also in texture and destructibility), but having essentially the same structure, Traces of cellularity are some- times discoverable on the external surface; P. nobilis has a distinct prismatic-cellular layer externally. (Carpenter.) Sub-genera, Neithea, Drouet, Vola, Klein. P. quinque- costatus and other fossil species with concayo-convex valves and distinct hinge-teeth; the inner layers of these shells are wanting in all specimens from the English chalk. Pailium, Schum. P. plica, Pl. XVI., Fig.8. Hinge obscurely toothed. Hinnites (Cortesii) Defr. P. pusio, Pl. XVI., Fig. 10. Shell regular and byssiferous when young; afterwards cementing its lower valve and becoming more or less irregular. Distribution, 2 species. Fossil, Trias? Upper Greensand —, Europe. Hemipecten, A. Adams. H. Forbesianus, Pl. XVI., Fig. 9. Shell hyaline, posterior ears obsolete, anterior prominent; right valve flat, byssal sinus deep; structure permeated by microscopic tubuli, as in Lima. Amusium, Klein. Shell nearly equivalved, gaping in front and behind; smooth outside, generally marked with radiating grooves inside. | Distribution, 176 species. World-wide; Nova-Zembla—Cape Horn ; — 200 fathoms. Fossil, 450 species (including Ayiculo-pecten). Carb.—. World-wide. | Lima, Bruguiere. Etymology, lima, a file. Example, Li. squamosa, Pl. XVI., Fig. 11. (Ostrea lima, L Synonyms, Plagiostoma (Lluwyd), Sby. P. cardiuformé, Pi oyih,, sites 2. Shell equivalye, compressed, obliquely oval; anterior sife CONCHIFERA. == 413 straight, gaping, posterior rounded, usually close; umbones apart, eared; valves smooth, punctate-striate, or radiately ribbed aud imbricated; hinge area triangular, cartilage pit central; adductor impression lateral, large, double; pedal scars 2, small. Animal, mantle-margins separate, inner pendent, fringed with long tentacular filaments, ocelli inconspicuous; foot finger-like, grooved; lips with tentacular filaments, palpi small, striated inside; gills equal on each side, distinct. The shell is always white; its outer layer consists of coarsely- plicated membranous lamelle ; the inner layer is perforated by minute tubuli, forming a complete network. (Carpenter.) The Limas are either free or spina byssus; some make an artificial burrow when adult, by spinning together sand or coral- fragments and shells, but the habit is not constant. (Forbes.) The burrows of LZ. hians are several times longer than the shell, and closed at each end. (Charlesworth.) ‘‘ This species is pale or deep crimson, with an orange mantle; when taken out of its nest it is one of the most beautiful marine animals to look upon, it swims with great vigour, like the scallop, by opening and closing its valves, so that it is impelled onwards or upwards in a succession of jumps. The filaments of the fringe are easily broken off, and seem to live many hours after they are detached, twisting themselves like worms.” (Landsborough.) L. spinosa has conspicuous ocelli, and short filaments. Sub-generu, Limatula, 8. Wood. L. sub-auriculata, Pl. XVI., Fig. 18. Valves equilateral; 8 species. Greenland—bBritain. Fossil, Miocene—. THurope. Limea, Bronn. UL. strigilata, Pl. XVI. Fig. 14.* Hinge minutely toothed. Fossil, 4 species. Lias—Pliocene. The recent Limca ? Sarsii (Lovén), Norway (=L. crassa of the #gean ?) has the mantle-border plain. Some of the larger recent species have obscure lateral teeth. Distribution, 20 species. Norway, Britain, West. Indies, Canaries, India, Australia; 1—150 fathoms. The largest living species (L. excavata, Chemn.) is found on the coast of Norway. Fossil, 200 species. Carb.? Trias—. United States, Europe, India. The so-called Plagiostoma spinosum is a Spondylus. SPONDYLUS (Pliny) L. Thorny-oyster. Type, S. geedaropus, L. Hxample, 8. princeps, Pl. XVI., Fig. 15 * After Bronn; the figure in Brocchi does not show the teeth. 414 MANUAL OF THE MOLLUSCA. Synonyms, Dianchora, Sby. Podopsis, Lam. Pachytes, Defr. © Shell irregular, attached by the right valve, radiately ribbed, spiny or foliaceous; umbones remote, eared; lower valve with a triangular hinge-area, cartilage in a central groove, nearly or quite covered; hinge of two curved interlocking teeth in each valve; adductor impression double. Animal, with the mantle open and gills separate, as in Pecten ; lips fohaceous, palpi short; foot small, cylindrical, truncated. In aged specimens the circular portion of the muscular scar exhibits dendritic vascular markings. The lower valve is always most spiny and least coloured ; in some species (like S. imperialis) the shell is scarcely, if at all, attached by its beak or spines. The inner shell-layer is very distinct from the outer, and always wanting in fossil specimens from calcareous rocks, then called Dianchore. Specimens from the Miocene of St. Domingo, which have lost this layer, contain a loose mould of the original interior. Water-cavities are common in the inner layer, the border of the mantle having deposited shell more rapidly than the umbonal portion. (Owen, Mag. Nat. Hist. 1838, p. 409.) Distribution, 68 species. West Indies, Canaries, Mediter- ranean, India, Torres Straits, Pacific, West America :—1065 ~ fathoms. Fossil, 80 species. Carb—. Europe, United States, India. Sub-genus, Pedum, Brug. P. spondyloides, Pl. XVL, Fig. 16. Shell thin, smooth, compressed, attached by a byssus passing through a deep notch in the right valve. Inhabits coral-reefs, where it is found half-embedded; Red Sea, Indian Ocean, Mauritius, Chinese Seas. PLICATULA, Lamarck. Etymology, plicatus, plaited. Tape. we. cristaua, Pix VL Wie 17, Shell irregular, attached by the umbo of the right valve valve smooth or plaited; hinge-area obscure; cartilage qui internal; hinge-teeth, two in each valve; adductor scar simpl¢. Animal resembles spondylus. Distribution, 9 species. West Indies, India, Philippine, Australia, West America. Fossil, 40 species. Trias—. United States, Hurope, Algeria, India. | P. Mantelli (Lea) Alabama, has the valves eared. CONCHIFERA. 415 Famity IJ.—Avicunip#. Wing-shells. Shell inequivalve, very oblique, resting on the smaller (right) valve, and attached by a byssus; epidermis indistinct: outer layer prismatic-cellular (Fig. 217), in- terior nacreous; posterior muscular im- pression large, sub-central, anterior small, within the umbo ; pallial line, irregularly dotted; hinge-line straight, elongated ; umbones anterior, eared, the posterior ear wing-like; cartilage contained in one or several grooves; hinge edentulous, or obscurely toothed. Animal with the mantle-lobes free, their margins fringed ; foot small, spinning a byssus; gills two on each side, crescent-shaped, entirely free (Desh.) or united to each other posteriorly, and to the mantle (as in the Oyster, and not as in Pecten). The wing-shells, or pearl-oysters, are natives of tropical and temperate seas; there are no living species in northern latitudes, where fossil forms are very numerous. Fig. 217. Pinna.* AvIcULA (Klein), Bruguiere. Etymology, avicula, a little bird. Type, A. hirundo, Pl. XVI., Fig. 18. Shell obliquely oval, very imequiyalye; right valve with a byssal sinus beneath the anterior ear; cartilage pit single, oblique; hinge with one or two small cardinal teeth, and an elongated posterior tooth, often obsolete; posterior muscular impression (adductor and pedal) large, sub-central; anterior (pedal scar) small, umbonal. Animal (of meleagrina) with mantle-lobes united at one point by the gills, their margins fringed and furnished with a pendent curtain; curtains fringed in the branchial region, plain behind ; foot finger-like, grooved; byssus often solid, cylindrical, with an expanded termination; pedal muscles four, posterior large in front of the adductor; adductor composed of two elements ; retractors of the mantle forming a series of dots, and a large spot near the adductor; lips simple; palpi truncated; gills equal, crescentic, united behind the foot. (British Museum.) * The cellular structure may be seen with a hand-lens, in the thin margin of the shell, by holding it up to the light ; or on the edges of broken fragments. 416 MANUAL OF THE MOLLUSCA. Distribution, 25 species. Mexico, South Britain, Mediter- ranean, India, Pacific :—20 fathoms. Fossil, 300 species. Lower Silurian —. World-wide. Sub-genera Maleagrina, Lam. Margaritophora, Muhlfeldt. M. margaritifera, Pl. XVI., Fig. 19. The ‘‘ pearl-oysters” are less oblique than the other avicule, and their valves are flatter and nearly equal; the posterior pedal impression is blended - with that of the great adductor. They are found at Madagascar, Ceylon, Swan River, Panama, &c. Manillais the chief port to which they are taken. There are three principal kinds, which are worth from £2 to £4 per cwt. :—1. The silver-lipped, from the Society Islands, of which about twenty tons are annually im- ported to Liverpool. 2. The black-lipped, from Manilla, of which thirty tons were imported in 1851. 38. A smaller sort from Panama, 200 tons of which are annually imported; in 1851 a single vessel brought 340 tons. (T.C. Archer.) These shells afford the ‘‘ mother-o’-pearl” used for ornamental pur- poses; and the ‘‘ oriental”’ pearls of commerce (p. 30, 31). Mr. Hope’s pearl, said to be the largest known, measures 2 inches long, 4 round, and weighs 1,800 grains. Pearl-oysters are found in about 12 fathom water; the fisheries of the Persian Gulf and Ceylon have been celebrated from the time of Pliny. Malleus, Lam. M. vulgaris, Pl. XVI., Fig. 20. The ‘‘hammer- oyster”? is remarkable for its form, which becomes extremely elongated with age; both ears are long, and the umbones central. When young it is lke an ordinary Avicula, with a deep byssal notch in the right valve. 6 species. China, Australia. Vulsella, Lam. YV. lingulata, Pl. XVI, Fig. 21. Synonym, Reniella, Sw. Shell, oblong, striated, sub-equivalve; umbones straight, earless. Often found imbedded in living sponges. Distribution, 7 species. Red Sea, India, Australia, Tasmania. Fossil, 7 species. U. Chalk —. Britain, France. Pteroperna, Lycett, 1852. P. costatula, Desl. Sell with a long posterior wing; hinge-line bordered by a groove; anterior teeth numerous, minute; posterior one or two, long, nearly parallel with the hinge-margin. /ossi/,3 species. Bath oolite ; Britain, France. ? Aucella (Pallasi1), 1846. Very inequivalye; left umbo pro- minent, earless; right valve small and flat, with a deep sinu beneath the small anterior ear. fossil, 4 species, Permian Gault. Europe. ‘‘In A. cygnipes we find no trace of prismati cellular structure or nacre, but the coarsely corrugated an somewhat tubular structure of the Pectens.” (Carpenter.) —_ = i CONCHIFERA. 417 Ambonychia (bellistriata), Hall, 1847. Nearly equivalve, gibbose, oblique, obtusely winged. A. vetusta (Inoceramus, Sby.) is concentrically furrowed; the right valve has a small anterior ear (usually concealed) separated by a deep and narrow sinus. fossil, 12 species. Lower Silurian — Carb. United States, Hurope. ? Cardiola (interrupta), Broderip, 1844. Hquivalve, gibbose, obliquely oval, radiately ribbed; beaks prominent; hinge-area short and flat. Jossil, 17 species. Upper Silurian — Dev. United States, Europe. ? Hurydesma (cordata), Morris; Devonian? New South Wales. Shell equivalve, sub-orbicular, ventricose, very thick near the beaks; ligimental area long, wide, sub-internal; byssal groove close to the umbo; right valve with a large, blunt hinge-tooth; adductor impression single, placed anteriorly; pallial line dotted. Pterinea (levis), Goldf. 1832. Shell thick, rather inequivalve, very oblique and broadly winged ; beaks anterior; sinus shallow; hinge-area long, straight, narrow, striated lengthwise; ante- rior teeth few, radiating; posterior teeth laminar, elongated ; anterior (pedal) scar deep, posterior (adductor) impression large, very eccentric. Jossil, 32 species. Lower Silurian — Carb. United States, Hurope, Australia. Pteronites (angustatus) M‘Coy, 1844, is thinner and has the teeth, &c., less developed. Monotis, Bronn, 1830. M. Salinaria, Schl. Trias, Hallein. Obliquely oval, compressed, radiated; anterior side short, rounded ; posterior slightly eared. Synonym, ? Halobia (salinarum) Br. 1830. Trias, Hallstadt. Semi-oyal, radiated, compressed, with a shallow sinus in front ; hinge-line long and straight. PosipONoMYA, Bronn. Synonym, Posidonia, Br. 1838 (not Konig). Poseidén, Neptune. Type, P. Becheri, Pl. XVI., Fig. 22. Shell thin, equivalve, compressed, earless, concentrically furrowed; hinge-line short and straight, edentulous. Fossil, 50 species. Lower Silurian — Trias. United States, Eurcpe. P AVicULO-PECTEN, M‘Coy, 1852. Type, Pecten granosus, Sby. . Min. Con. t. 574. Shell inequivalve, sub-orbicular, eared; hinge-areas flat, with several long, narrow cartilage furrows, slightly oblique on each side of the umbones ; right valve with a deep and narrow byssal snus beneath the anterior ear; adductor impression large, T 3 418 MANUAL OF THE MOLLUSCA. simple, sub-central; pedal scar small and deep, beneath the umbo. Fossil (see Pecten). Lower Silurian — Carb. Spitzbergen — Australia. GERVILLIA, Defrance. Etymology, dedicated to M. Gerville, a French naturalist. Example, G. anceps, Pl. XVIL., Fig. 1. Sheil like Avicula; elongated; anterior ear small, posterior wing-like; area long and flat, cartilage pits several, wide apart ; hinge-teeth obscure, diverging posteriorly. Fossil, 37 species. Carb. — Chalk. Europe. Sub-genus? Bakewellia, King. B. ceratophaga, Schl. Fossil, 5 species. Permian, Britain, Germany, Russia. Shell small, inequivalve, cartilage pits 2—d; hinge with anterior and pos- terior teeth; anterior muscular impression and pallal line distinct. PERNA, Bruguiere. Etymology, perna, a shell-fish (resembling a gammon), Pliny. Synonyms, Melina, Retz. Isognomon, Klein. Pedalion, Solander. Type, P. ephippium, L. Pl. XVII, Fig. 2. | Shell nearly equivalve, compressed, sub-quadrate; area wide, | cartilage pits numerous, elongated, close-set ; right valve with a Se sinus; muscular impression double. The Pernas vary in form like the Avicule; some are very obliqtie, some very inequivalve, and many fossil species have the posterior side produced and wing-like. In some Tertiary Pernas the pearly layer is an inch thick. Distribution, 18 species. Tropical seas; West Indies — India — West America. Fossil, 30 species. Trias —. United States, Chili, Europe. Sub-genera, Crenatula, Lamk. C. viridis, Pl. XVI., Fig. 24. Shell thin, oblong, compressed ; byssal sinus obsolete; cartilage pits shallow, crescent-shaped. Distribution, 8 species, North Africa, Red Sea — China; in sponges. Jossi/, 4 species. ' Hypotrema, D’Orb, 1853. H. rupellensis (= ? Pulvinites Adansonii, Defrance, 1826); Coral-rag, Rochelle. Shell oblong, inequivalye; right valve flat or concave, with a round byssal foramen near the hinge; left valve convex, with a muscular impression near the umbo; hinge-margin broad, curved, wit about twelve close-set transverse cartilage grooves. ; CONCHIFERA. 419 INOCERAMUS, Sowerby (1814). Hiymology, ts (inos), fibre, keramos, shell. Haxample, I. sulcatus, Pl. XVII., Fig. 3. Synonym, Catillus, Brongn. Shell inequivalve, ventricose, radiately or concentrically furrowed, umbones prominent; hinge-line straight, elongated ; cartilage pits transverse, numerous, close-set. This genus differs from Perna chiefly in form. TJ. involutus has the left valve spiral, the right opercular. J. Cuviert attains the length of a yard. Large flat fragments are common both in the chalk and flints, and are often perforated by the Cliona. Hemispherical pearls have been found developed from their inner surface, and spherical pearls of the same prismatic-cellular structure occur detached, in the chalk. (Wetherell.) The Jno- cerami of the gault are nacreous. Fossil, 75 species. ? Silurian — Chalk. South America, United States, Europe, Algeria, Thibet. Pinna, L. Etymology, pinna, a fin or wing. Type, P. squamosa, Pl. XVI., Fig. 23. Shell equivalve, wedge-shaped; umbones quite anterior; posterior side truncated and gaping; ligamental groove linear, elongated; hinge edentulous; anterior adductor scar apical, posterior sub-central, large, ill-defined; pedal scar in front of posterior adductor. Animal with the mantle doubly fringed; foot elongated, grooved, spinning a powerful byssus, attached by large triple muscles to the centre of each valve; adductors both large; palpi elongated; gills long. Distribution, 80 species. United States, Britain, Mediter- ranean, Australia, Pacific, Panama. Fossil, 60 species. Devonian —. United States, Europe, South India. The shell of the Pinna attains a length of two feet; when young it is thin, brittle, and translucent, consisting almost entirely of prismatic cell-layers; the pearly lining is thin, divided, and extends less than half-way from the beak. Some fossil Pinnas crumble under the touch into their component fibres. The living species range from extreme low water to 60 fathoms ; they are moored vertically, and often nearly buried in sand, with knife-like edges erect. The byssus has sometimes been mixed with silk, spun, and knitted into gloves, &c. (Brit. 420 MANUAL OF THE MOLLUSCA. Mus.} A little crab which nestles in the mantle and gills of the Pinna, was anciently believed to have formed an alliance with the blind shell-fish, and received the name of Pinna-guardian (Pinnoteres) from Aristotle; similar species infest the Mussels and Anomic of the British coast. Sub-genus, Trichites (Plott), Lycett. T. Plotti, Llhwyd. (‘‘Pinnigene,” Saussure.) Shell thick, inequivalve, somewhat . irregular, margins undulated. fossil, 5 species. Oolitic strata of England and France. Fragments an inch or more in thick- ness are common in the Cotteswold-hills; full-grown individuals are supposed to have measured a yard across. Faminy IIl.—Myritipm. Mussels. Shell equivalve, oval or elongated, closed, umbones anterior, epidermis thick and dark, often filamentose; ligament internal, sub-marginal, very long; hinge edentulous; outer shell layer obscurely prismatic-cellular ;* inner more or less nacreous; pallial line simple; anterior muscular impression small and narrow, posterior large, obscure. | Animal marine or fluviatile, attached by a byssus; mantle- lobes united between the siphonal openings; gills two on each | side. elongated, and united behind to each other and to the | ' mantle, dorsal margins of the outer and innermost laminz free ; foot cylindrical, grooved. The members of this family exhibit a propensity for conceal- ment, frequently spinning a nest of sand and shell-fragments, burrowing in soft substances, or secreting themselves in the burrows of other shells. Mytinus, L. Sea-mussel. Example, M. smaragdinus, Pl. XYVII., Fig. 4. Shell wedge-shaped, rounded behind; umbones terminal, pointed ; hinge-teeth minute or obsolete ; pedal muscular im- pressions two in each valve, small, simple, close to the adductors. Animal with the mantle-margins plain in the anal region, and projecting slightly; branchial margins fringed; byssus strong and coarse; gills nearly equal; palpi long and pointed, free. The common edible mussel frequents mud-banks which are uncovered at low-water; the fry abound in water a few fathom deep; they are full-grown in asingle year. From some un * A thin layer of minute cells may frequently be detected immediately under epidermis. (Carpenter.) CONCHIFERA. 491 known cause they are at times extremely deleterious. The consumption of mussels in Edinburgh and Leith is estimated at 400 bushels (= 400,000 mussels) annually ; enormous quan- tities are also used for bait, especially in the deep sea fishery, for which purpose thirty or forty millions are collected yearly in the Firth of Forth alone. (Dr. Knapp.) Mussels produce small and inferior pearls. At Port Stanley, Falkland Islands, Mr. Macgillivray noticed beds of mussels which were chiefly dead, being frozen at low-water. UM. bilocularis (Septifer, Recluz) has an umbonal shelf for the support of the anterior adductor, like Dreissena ; it is found at Mauritius and Australia. M. exustus (Brachydontes, Sw.) has the hinge-margin denti- culated continuously. Distribution, 65 species. World-wide. Ochotsk, Behring’s Sea, Russian Ice-meer; Black Sea, Cape Horn, Cape, New Zealand. Fossil, 100 species. Silurian —. United States, Europe, South India. ? Myaina, Koninck, 1842. Types, M. Goldfussiana, Kon. Carb. M. acuminata, Sby. Permian. Shell equivalve, mytili-form; beaks nearly terminal, septi- ferous internally; hinge-margin thickened, flat, with several longitudinal cartilage-grooves; muscular impressions two; pallial line simple. Fossil, 6 species. Carb. — Permian. Hurope. The liga- mental area resembles that of the recent Arca obliquata, Chemn. India. MopioLa, Lam. Horse-mussel. itymology, modiolus, a small measure, or drinking-vessel. Haample, M. tulipa, Pl. XVII., Fig. 5. M. modiolus, p. 403, Fig. 214. Shell oblong, inflated in front; umbones anterior, obtuse; hinge toothless; pedal impressions three in each valve, the central elongated; epidermis often produced into long beard- like fringes. . Animal with the mantle-margin simple, protruding in the branchial region; byssus ample, fine; palpi triangular, pointed. The Modiole are distinguished from the Mussels by their habit of burrowing, or spinning a nest. Low water—100 fathoms. 492 MANUAL OF THE MOLLUSCA. Distribution, 70 species, chiefly tropical; I. modiolus, Arctic seas — Britain. Fossil, 150 species. Silurian? Lias —. United States, Europe, Thibet, South India. | Sub-genera. Lithodomus, Cuy. M. lithophaga, Pl. XVIL., Fig. 7. Shell cylindrical, inflated in front, wedge-shaped behind; epidermis thick and dark; interior nacreous.* Distribution, 40 species. West Indies — New Zealand. Fossil, 35 species. Carb. —. Europe, United States. The ‘‘date-shell” bores into corals, shells (Fig. 25, p. 84), and the hardest limestone rocks ; its burrows are shaped like the shell, and do not admit of free rotatory motion. The animal, which is eaten in the Mediterranean, is like a common mussel; in L. patagonicus the siphons are produced. Like other burrowing shell-fish, they are luminous. Perforations of Lithodomi in limestone cliffs, and in the columns of the Temple of Serapis at Puteoli, have afforded conclusive evidence of changes in the level of sea- coasts in modern times. (Lyell’s ‘‘ Principles of Geology.’’) Crenella, Brown. OC. discors, Pl. XVII., Fig. 8. (Lanistes, Sw. Modiolaria, Beck.) Shel/ short and tumid, partly smooth, and partly ornamented with radiating strize; hinge-margin crenulated behind the ligament; interior brilliantly nacreous. Animal with the anal tube and branchial margins prominent. Distribution, 24 species. Temperate and arctic seas; Nova Zembla, Ochotsk, Britain, New Zealand. Low water — 40 fathoms. Spinning a nest, or hiding amongst the roots of sea- weed and corallines. JM. marmorata, Forbes, burrows in the test of Ascidia. fossil, 12 species. Upper Greensand —. Europe. Modiolarca (trapezina), Gray ; Falkland Islands — Kerguelen, attached to floating sea-weed ; mantle-lobes united, pedal open- - ing small, foot with an expanded sole, front adductor round. M. ? pelagica, Pl. XVII., Fig. 6, is found burrowing in floating blubber, off the Cape. (Forbes.) 2 living species. ? Mytilimeria (Nuttall), Conrad. Shell irregularly oval, thin, edentulous, gaping posteriorly ; umbones sub-spiral; ligament short, semi-internal. Distribution, California; animal gre- garious, forming a nest. Modiolopsis (mytiloides), Hall, 1847 ( — Cypricardites, part, Conrad. Lyonsia, part, D’Orb.). Shell like modiola, thin and smooth, front end somewhat lobed; anterior adductor scar * The outer shell-layer has a tubular structure; the tttbes are excessively minut seldom branching, oblique and parallel. Carpenter.) CONCHIFERA. 493 large and oval. Fossil, 15 species. Silurian, United States, Kurope. ? Orthonotus (pholadis), Conrad. Lower Silurian, New York. Shell elongated, margins parallel, umbones anterior, back plaited.* ; - Myrina, Adams. Modiola pelagica, has the mantle open; the shell is peculiar from the large size of the anterior muscular impression; and the subcentral umbones distinguish it from Modiolarca. Hoplomytilus (crassus), Sdbgr. Devonian, Nassau. Shell with a muscular plate in the umbo, like Septifer. The Mytilus squamosus, Sby. Magnesian limestone, Brit., has a similar plate. HIerpomMya. Salter. Shell gibbous, with anterior inflated close beaks, a long cardinal edge; anterior edge short, rounded, and separated by a strong sinus from the inflated posterior ridge and slope. Fossil, 1 species. Devonian. DREISSENA, Van Beneden. Etymology, dedicated to Dreyssen, a Belgian physician. Synonyms, Mytilomya, Cantr. Congeria, Partsch. Ticho- -gonia, Rossm. Type, D. polymorpha, Pl. XVII., Fig. 9. (Mytilus Volge, Chemn.) Shell like Mytilus, without its pearly lining; inner layer com- posed of large prismatic shells; um- bones terminal; yalves obtusely keeled ; right valve with a slight byssal sinus; anterior adductor supported on a shelf within the beak ; pedal impression single, * @, posterior. r Animal with the mantle closed ; byssal orifice small; and siphon very small, coni- cal, plain, branchial prominent, fringed _—‘Fig: 218. Dreissena. inside; palpi small, triangular; foot-muscles short and thick, close in front of the posterior adductor. ~ D. polymorpha is a native of the Aralo-Caspian rivers; in 1824 it was observed by Mr. J. Sowerby in the Surrey docks, * Hall and Salter employ the name 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 Mucula. 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. Hurope, America, Africa. Fossil, 13 species. Hocene—. Britain, Germany. Famity 1V.—ARcADz. Shell regular, equivalve, with strong epidermis; hinge with a long row of similar, comb-like teeth; pallial line distinct ; muscular impressions subequal. Structure corrugated, with vertical tubuli in rays between the ribs or strize. (Carpenter.) Animal with the mantle open; foot large, bent, and deeply grooved; gills very oblique, united posteriorly to a membranous septum. . Arca, L. ktymology, arca, a chest. Type, A. Nox, Pl. XVII, Fig. 12. Synonyms, Barbatia, Gray; Anomalocardia, Klein; Scapharca, Gray; Scaphula, Benson. Examples, A. granosa, Pl. XVIL., Fig. 10. A. pexata, Fig. 11. A. zebra, Fig. 13. Shell equivalve or nearly so, thick, sub-quadrate, ventricose, strongly ribbed or cancellated; margins smooth or dentated, close or sinuated ventrally; hinge straight, teeth very numerous, transverse; umbones anterior, separated by a flat, iozenge- shaped ligamental area, with numerous cartilage-grooves; pallial line simple; posterior adductor impression double; pedal scars 2, the posterior elongated. ; Animal with a long pointed foot, heeled, and deeply groved ; mantle furnished with ocelli; palpi 0; gills long, narrow, less striated externally, continuous with the lips; hearts two, each with an auricle. The name Bysso-arca was chosen unfortunately by Swainson, for the typical species of the genus, in which the byssal orifice is sometimes very large (Pl. XVII., Fig. 13). The byssus is a horny cone, composed of numerous thin plates, occasionally becoming solid and calcareous ; it can be cast off and re-formed with great rapidity. (Forbes.) ‘The Arcas with close valves have the left valve a little larger than the right, and mor ornate. The Bysso-arks secrete themselves nder stones at low water, CONCHIFERA. 495 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. ITT., 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, 1s found in the Ganges and its branches, from Calcutta to Humeerpoor on the Jumna, 1,000 miles from the sea. A second species has been found in the river Tenasserim, Birmah. The hinge is edentulous in the centre, and the posterior teeth are laminar and branched; the elements of the posterior muscular impres- sion are distinct. | Fossil, 400 species. Lower Silurian—. United States, Europe, South India. CucuLL@A, Lamarck. Hiymology, cucullus, a cowl. Type, C. concamerata, Pl. XVIT., 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, Kurope. Sub-genus, Macrodon, Lycett. M. Hirsonensis, Pl. XVII., Fig. 15. Shell with a few oblique anterior teeth and one or more long laminar posterior teeth. The Ark-shells of the Paleozoic and secondary strata have their anterior teeth more _or less oblique, like 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. PECTUNCULUS, Lam. _ Type, P. pectinifermis, Pl. XVII., Fig. 16. (Arca pectun- culus, L.) Shellorbicular, nearly equilateral, smooth or radiately striated ; umbones central, divided by a striated igamental 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 Sem 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 seen are obliterated by encroachments of the liga- ment. Limopstis, Sassi, 1827. Tape, Ma. anurite, el Xev ale abet ie Synonym, Trigonocceia, Nyst. Pectunculina, D’Orb. Shell orbicular, convex, shghtly oblique; hgamental area with a trianguiar cartilage-pit in the centre; hinge with 2 equal, curved cee of transverse teeth. | Distribution, 4 species. Red Sea (Nyst.), Japan, Britain. Mr. M‘Andrew has dredged LZ. pygmea, living, on the coast of Finmark; it isa fossil of the Pliocene of England, Belgium, and Sicily. Fessil, 36 species. Bath-oolite—. United States Hurope. Nucuta, 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 th CONCHIFERA. 497 foot. N. mirabilis, Adams, from Japan, is sculptured like the extinct NV. Cobboldic. Distribution, 70 species. United States, Norway, Cape, Japan, Sitka, Chili. On coarse bottoms, from 5—100 fathoms. Fossil, 177 species. Lower Silurian?—. Trias—. America, Europe, India. Sub-genera. Nuculina, D’Orb.* 1847. N. miharis, Pl. XVITI., 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 haying an external ligament. ? Stalagmium (margaritaceum), Conrad, 1833—Myoparo cos- tatus; Lea. Hocene; Alabama. ? S.Nysti7, Galeotti (Nucunella, D’Orb.). ocene, Belgium. Shell like Limopsis; ligamental area narrow, wholly posterior. IsoArcA, Minster, 1842. Type, 1. 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, 1s 3 inches long, and has the ligament preserved. Fossti, 14 species. Lower Silurian—Chalk. North America. Europe. Sub-genera. Cucullella, M‘Coy. OC. antiqua, Sby. Upper Silurian, Herefordshire. Shelli elliptical, with a strong rib behind the anterior adductor impression. Lunularca, 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. Euample, lL. caudata, Pl. XVII., Fig. 20. Shell resembling Nucula ; oblong, rounded in front, produced and pointed behind; margins even; pallial line with a snall sinus; umbonal area with a linear impression joining the ante- rior adductor. Animal furnished with two partially-united, slender, unequil, * WN. 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). 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. a, a, adductors ; p, p, pedal muscles; J, ligament; g, gills; s, siphons (much con- tracted); ¢, c, labial palpi and appendages ; 7, intestine ; f, foot ; x, z, lateral muscles of 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 shell; mantle-margiz plain in front, fringed behind; destitute of ventral lobes. Distribution, Arctic and Antarctic Seas, Green- land, Massachusetts, Brazil, Norway, Kamtschatka. Yoldia limatula (Fig. 220) has been dredged, alive, by Mr. M‘Andrew, on the coast of Finmark. Itis also found in Portland Harbour, Massachusetts. The animal is very active, and leaps to an astonishing height, exceeding in this faculty the scollop-shells. CONCHIFERA. 429 (Dr. Mighels.) Fossil, Phocene—. (Crag and Glacial deposits.) England, Belgium. Fig. 220. Yoldia limatula (after Barrett). SOLENELLA, Sowerby. Type, S. 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. Pr SoLEMYA, 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; ampones poste- rior; hinge edentulous; ligament Epmecalede pallial line obscute. Outer layer oO 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 gills, 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. TrRIGONIA, 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 ee Bde vt concentric ribs; posterior side —— angular; ligament small and prominent; hinge-teeth 2.3, diverging, transversely stri- \.----0 ated; centre tooth of left valve \rc4? divided; pedal impressions in \ASil--m front of the posterior adductor, \c and one in the umbo of the x left valve; anterior adductor Iii pression close to the umbo. Animal with a long and pointed foot, bent sharply, heel prominent, sole bordered by two crenulated ridges; palpi small and pointed; gills ample, the outer smallest, united behind the .- body to each other and to the mantle. The shell of Trigonia is almost entirely nacreous, and usually wanting or metamorphic in limestone strata; casts of the in- * Fig. 221. From a specimen in alcohol; the gills slightly curled and contracted, they should terminate near the margin, between the arrows which indicate the inhalent and exhalent currents: a, a', adductors; AJ, ligament ; ¢, t’, dental sockets ; 0, mouth; é t, labial tentacles or palpi; p, pallial line; m, margin ; f, foot; »v, cloaca. CONCHIFERA. 431 terior are called ‘‘ horse-heads” by the Portland qtiarry-men ;* they spoil the stone. Silicified casts have been found at Tisbury, in which the animal itself, withits 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. 8. 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 ’), Austraha. Fossil, 100 species. Trias — Chalk (not known in Ter- tiaries). Hurope, 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 Trigonia. 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 ; hgament 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, Hurope. 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. } 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. ne 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 Gs) radiating teeth, striated ACTOSS ; Hornet) external. Fossil, 4 species. Lower Silurian: Canada, United States, Britain. af Famity VI.—UNIonNIDmA. Naides. Shell usually regular, equivalve, closed; structure nacreous, with a very thin prismatic-cellular layer beneath the epidermis ; epidermis thick and dark; ligament external, large and pro- minent; margins even; anterior hinge-teeth thick and striated, posterior laminar, sometimes wanting ; adductor scars deculy impressed ; aeial 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 aise by the admirers of artificial systems; fortunately, how- ever, M. D’Orbigny has ascertained that the Mulleria, which CONCHIFERA. 435 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 unionide 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. Htymology, unio, a pearl (Pliny). Haample, U. litoralis, Pl. XVITI., 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, lateraliy 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. { 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. ° } 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 im 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 peazl, 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.) Anaccount of the Irish pearl- fishery was given by Sir R. Redding, in the Phil. Trans., 1693. The mussels were found set up im 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, Pe OVE ieee 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. XVIIT., Fig. 3. Synonyms, Pachyodon and Prisodon, Schum. Shell Arca-shaped, hinge-line straight, with a dorsal wing on the posterior side; teeth elon- gated, transversely striated. Distribution, 4 species. S. America. CasTALTA, 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. | Awnopon, Cuvier. Swan-mussel. Type, A. cygneus, Fig.:208, p. 398. Etymology, 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—. Hurope. M. D’Orbigny relates that he found great quantities of small Anodons (Bysso-anodonta Paraniensis, D’Orbigny) 4 lines in length, attached by a byssus, in the River Parana, above Corrientes. | CONCHIFERA. 435 Iripina, Lamarck. Synonyms, Mutela, Scop. Spatha, Lea (including Mycetopus). Leila, Gray. Type, 1. exotica, Pl. XVIII., Fig. 5. Etymology, iris, the rainbow. Shell oblong ; umbones depressed ; hinge-line long, straight, attenuated towards the umbones, crenated by numerous unequal teeth ; ligament long and narrow. Animal with mantle-lobes united posteriorly, forming two short siphons; mouth and lips small; palpi immense, oval; gills united to the body. Iridina ovata (Pleiodon, Conrad) has a broader hinge-line. Distribution, 9 species. Rivers of Africa, Nile, Senegal. Mycetorus, D’Orbigny. Etymology, mukes, a mushroom, pous, the foot. Type, M. soleniformis, Pl. XVIII., 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. AMTHERIA, Lamarck. Type, Ai. semilunata, Pl. XVITI., Fig. 7. (Aitherios, aérial.) Shell irregular, mequivalve ; 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, Acostea (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; umboues 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 Granada. 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.f 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.—CHAMIDA. 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. bad CHAMA (Pliny), L. Example, C. macrophylla, Pl. XVIII., Figs. 8, 9. Synonym, Arcinella, Schum. Shell attached usually by the Je/¢ 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 shghtly prominent, fringed, anal with a simple valve; foot bent, or heeled; liver occupying the umbo of the attached valve only ; ovary extending into both mantle-lobes, as far as aN SE £Qz = S== SS i z hj Z tf Ati ANN | a | iy AN x eee Fig. 223. Right side. Fig. 224. Left side. Fig. 223. 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; 6, branchial; 7, foot and pedal orifice; p, posterior pedal muscle; ¢, palpi; g, gills (contracted) ; J, liver; o, 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, J, m). Some Chamas are attached indifferently by either valve ; when fixed by the right valve the dentition is reversed, the left valve having the single tooth. 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? Monopleura; Matheron (= Dipilidia, Math.). M. imbricata, Math. Fig. 226. Neocomian, Southern France. Fig. 225. Bi-radiolites, 3- Fig 226. Monopleura, +. 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 lhgamental 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 DicEeRAs, Lamarck. Type, D. arietinum, Pl. XVIII., Figs. 10 and 11, and Figs. 227 and 228. Shell sub-equivalve, attached 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 haying constantly two hinge-teeth in the right a aA mr UL 5 Me | ites i fy \ \K \ tel tly oy UK Ql \ \\\ Fig. 227. Diceras arietinum, $. Fig. 228. Requienia ammonia, +. a, point of attachment ; 7, 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,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. Lonsdalii, Pl. XVIII, Fig. 12 and Fig. 230. R. ammonia, Fig. 189. Shell thick, very inequivalve, attached by the /e/t umbo; liga- ment 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, 4. Fig. 230. Requienia, + Internal casts; a, point of attachment; c, c', casts of dental pits; 7, ¢’, 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, ¢). The internal muscular ridges are produced by duplicatures of the shell-wall, and are indicated outside by grooves (Fig. 229, 7’). In R. sub- equalis and Toucasiana there is a second parallel ridge, as in Hippurites and Caprotina. Fossil, 7 species. Neocomian — lL. Chalk. Britain, France, Spain, Algeria, Texas. Famity VIII.—HIPPurRitTip#, (Order Rudistes, Lamarck.) Shell inequivalve, unsymmetrical, thick, attached by the right umbo; umbones frequently camerated; structure and sculpturing of valves dissimilar; ligamentinternal ; 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 Kastern 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 CONCHIFNRA: 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 laminge 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. xi. p. 40.) They are the most problematic of all fossils; there are no recent shells which can be supposed to belong to the same family; and the condition in which they usually occur has in- volved them in greater obscurity.* The characters which determine their position amongst the ordinary bivalves are the folowing :— 1. The shell is composed of three distinct layers. 2. They are essentially unsymmetrical, and right-and-left valved. 3. The sculpturing of the valves is dissimilar. 4. There is evidence of a large internal ligament. 5. The hinge-teeth are developed from the free valye. 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, Leoni. and Bronn Jahrb, p. 573. 2. Desmoulins, as a combination of the Tiinicary and Sessile Cirripede. 3. Dr. Carpenter, as a “ group intermediate between the Conchifera and Cirripeda.” An. Nat. Hist. XII. 390. 4, Prof. Steenstrup, of Copenhagen, as Annelids. 5. Mr. D. Sharpe refers Hippurites to the Balani; Caprineila to the Chamacee. 6. La Peyrouse considered the Hippurites Orthocerata; the Radiolites, Ostracea. 7. Goldfuss and D’Orbigny place them both with the Brachiopoda. 8. Lamarck and Rang, between the Brachiopoda and Ostracee. 9. Cuvier and Owen, with the Lamellibranchiate bivalves. 10. Deshavyes, 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. vu 3 442 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 cavity of the long-beaked oysters.* The inner layer ceases at the pallial line, beyond which, on the rim of the shell, the cellular structure is often apparent ; Fig. 231. Section of a fragment of Ostrea Cornucopie. obscure bifurcating impressions radiate from the pallial line ta the outer margin (Fig. 232, v, v). These have been compared to the vascular impressions of 45S Crania (Figs. 193, 194), and constitute the only argument for supposing the Ludistes 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 dental sockets, resembles an Orthoceras with a lateral siphuncle; whilst a Caprinella (Fig. 246), which has lost its outer layer, mu; ht be mistaken for an Ammonite. + Traced from the original specimen in the Museum of the School of Mines. 48, is the inner edge ; a, the outer edge; v, v, the dichotomous impressions; the horizontal laminz are seen on the shaded side. Lower chalk; Sussex. ra CONCHIFERA. 4438 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. XITX,, 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 hawe been exactly suited by its position and magnitude, but it is probable that,.like other bivalves, they opened to a very small extent. HIPPURITES, Lamarck. Name, adopted from old writers, ‘‘ fossil Hippuris,” or Horse-tail. Types, H. bi-oculatus, Lamarck, and H. cornu-vaccinum, Fig. 237. Shell very inequivalve, inversely conical, or elongated and cylindrical ; fixed valve striated or smooth, with three parallel furrows (J, m, n) on the cardinal side, indicating duplicatures _ of the outer shell layer; internal margin slightly plaited; pallial line continuous ; umbonal cavity moderately deep, ligamental inflection (/) 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 Aippurites, 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, andsome 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-1 allits layers (p. 361). me, 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 processes; ¢, c, cartilage pits; t,t’, teeth and dental sockets; «, umbonal cavity; p, orifices of canals; /, ligamental inflection; m mus- cular, 2 siphonal inflection. depressed. with a central umbo, and two grooves or pits cor- ase > 772 : AE I A A >») >. 1 7 5S Du pc Ih j Fig. 235. H. Toucasianus, upper valve, 3.4 Fig. 236. Lower valve, with mould, 3. i ligamental, m muscular, m siphonal inflections; -z, fracture, showing canals 3 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. { 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 imner margin; anterior cartilage-pit deep and conical, posterior shallow; umbonal cavity turned to the front (wv); 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, HA. cornu-vaccinum attains a length of more than a foot, and is curved like a cow’s horn; the outer layer separates readily from the core, which is furrowed longitudinally. The ligamental inflection (/) is very deep and narrow, and the anterior tooth farther removed from the side than in H. bi-oculatus and radiosus (Figs. 233, 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 Trigonia. The development of processes from the upper valve, for the Fig. 237. Longitudinal section ; upper half,+. Fig. 238. Transverse section, 4. Hippurites cornu-vaczinum, Bronn. Salzburg, 1, m, n, duplicatures ; u, umbonal cavity of left valve; 7, of right valve; c, c', care tilage-pits; ¢, t', teeth; a, a’, muscular apophyses; d, outer shell-layer. Fig. 257 is taken in the line d 6 of Fig. 238, cutting only the base of the posterior tooth (¢’). Fig. 238 is from a larger specimen, at about the ievel d 6 of Fig. 237, cutting the point of the posterior apophysis (@'), 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 c= BV S| SN ef ao re ' | a i \ A — a: raga (| CASTILE GI iy Z cw \\\ he , iI | iF Na Ta NE Sl Iv NE Fig. 239. Hippurites eornu-vaccinum. Fig. 240. Radiolites cylindraceus, +. Longitudinal sections taken through the teeth (¢, ¢') and apophyses (a, a’). @ outer, rv inner shell-layer ; 2, dental plate of lower valve; uw, umbonal cavity of upper valves ; 2, intestinal channel. Originals in Brit, Mus. and posterior adductor, winds round outside that muscle, and terminates in the linetof the exhalent current. There is a groove (sometimes an inch deep) round the second and third duplica- tures in the upper valve, which seems intended to facilitate the passage of the alimentary canal, and the flow of water from the gills into the exhalent channel. The smallness of the space for the branchize may have been compensated by deep plication of those organs, as In Chama and Tridacna. . Fossil, 30 species. Chalk. Bohemia, Tyrol, France, Spain, Turkey, Syria, Algeria, Egypt. RavDIoLITES, Lamarck, 1801. Etymology, radius, a ray. Synonym, Spheerulites, De la Metherie, 1805. Shell inversely conical, bi-conic, or cylindrical; valves dis- similar in structure; internal margins smooth or finely striated, simple, continuous; ligamental inflection very narrow, dividing CONCHIFERA. 447 the deep and rugose cartilage pits: lower valve with a thick outer layer, often foliaceous; its cavity deep and straight, with two Fig, 241. Interior of lower valve. Fig. 242. Interior of upper valve. Radiolites mammillaris, Math. 3. L. Chalk. S. Mamest, Dordogne. 1, ligamental inflection; m, pallial line; c, c, cartilage pits; a, a, adductor impressions and processes ; ¢, teeth and'dental sockets. : dental sockets and lateral muscular impressions; upper valve flat or conical, with a central umbo; outer layer thin, radiated ; | Fig. 243. Side views of the upper valve of R. mammillaris; 1, ligamental inflection 4 t, teeth; a, a’, muscular processes. umbonal cavity inclined towards the, ligament; teeth angular, striated, supporting,curved and sub-equal muscular processes. The upper yalve of #. flewriausus has an oblique umbo, with a distinct ligamental groove. The’foliations of the lower valve are frequently undulated; they are sometimes as thin as paper, and several inches wide. The umbonal cavity of the lower valve is partitioned off by very delicate funnel-shaped laminz. Specimens frequently occur in which the outer shell layer is preserved, whilst the inner is wanting, and the mould (‘ birostrites”’”) remains loose ‘a the centre. The interior of the outer shell layer is deeply 448 MANUAL OF THE MGLLUSCA,. grooved with lines of growth, and exhibits a distinct ligamental ridge in each valve. _ Im aged examples of R. calceoloides the ligamental inflection ~ 1s concealed, the cartilage pits partially filled up and smoothed, y) = —— 4, / Ys / Fig. 244. Upper view. Fig. 245. Side view. Internal mould of &. Heninghausii, Desm., 3. Chalk. &, umbe of left valve; r, right umbo; J, ligamental groove; c,c, cartilage; a, anteriof adductor muscle ; a’, posterior. and the teeth and apophyses so firmly wedged into their re- spective cavities, as to suggest the notion that the valves had become fixed about a quarter of an inch apart, and ceased to open and close at the will of the animal. Fossil, 42 species. Neocomian—Chalk. Texas; Britain, France, Bohemia, Saxony, Portugal, Algeria, Egypt. Sub-genus 2 Bi-radiolites, D’Orbigny. R. canaliculatus (Fig. 225, upper valve). Ligamental groove visible in one or both valves, sometimes occupying the crest of a ridge, and bordered by two similar areas (a, a). Fossil, 5 species. Chalk, France. CAPRINELLA, D’Orbigny. Type, C. triangularis, Desm. (Fig. 246). Synonym, Caprinula (Boissi), D’Orbigny. Shell fixed by the apex of the right valve, or free; composed of a thick layer of epen tubes, with a thin compact superficial lamina; cartilage internal, contained in several deep pits; umbones more or less camerated ; right valve conical or elon- gated, with a hgamental furrow on its convex side, and furnished with one strong hinge-tooth supported by an oblique plate: left CONCHIFERA, 449 valve oblique or spiral, with two hinge teeth, the anterior Fig. 246. Caprinella triangularis, Desm. U. Greensand, Rochelle, 2. A, portion of the left valve, after D’Orbigny,* the shell-wall is removed by weather- ing, exposing the camerated interior. B, mould of five of the water-chambers. C, mould of the body-chamber; u, umbo of right valve; s, of left valve; ¢, dental groove; a, surface from which the posterior lobe has been detached. From the originals in the Brit. Mus., presented by S. P. Pratt, Esq. supported by a plate which divides the umbonal cavity length- wise. In C. triangularis the umbonal cavity of the spiral valve is Fig. 247. Straight valve. Fig. 248. Spiral valve. Transverse sections of C. Boissiz, L. Chalk, Lisbon (Mr. Sharpe). J, position of ligamental inflection ; t, teeth ; c, cartilage pits ; u, umbonal cavity. Fig. 248 is from a weathered specimen, which has lost the outer layer. The tubes of the shell-wall are filled with limestone containing small shells. partitioned off at regular intervals (Fig. 246, A); the length of the water chambers is sometimes 3% inches, and of the body- * In M. D’Orbigny’s figure the smaller valve has been added from another speci- men, and is turned towards the spire of the large valve, (Pal. Franc. pl. 542, fig. — 1). In Mr, fratt’s specimens, and those collected by Mr. Sharpe in Portugal, the umbo of the smaller yalve is turned away with a sigmoid flexure. (Q. J. Geol. Soc, VI. pl. 18.) 450 MANUAL OF THE MOLLUSCA. chamber from 2 to 7 diameters; specimens measuring a yard across may be seen on the cavernous shores of the islets near Rochelle.* (Pratt.) Fossil, 6 species. Neocomian—Lower Chalk. France, Portugal, Texas. ~ KH > IN Res, oe Se ea i yj Fig. 249.C. Aguilloni, left valve. Fig. 250,.C. adversa (after D’Orb.). a, a, position of adductors; /, ligament; u, umbonal cavity; t, tooth of fixed valve, broken off and remaining in its socket ; c, original point of attachment, Caprina, C. D’Orbigny. itymology, caprina, pertaining to a goat. Synonym, Plagioptychus, Matheron. Type, O. Aguilloni, C. D’Orbigny. Lower Chalk, Tyrol (= C. Partschii, Hauer). Shell with dissimilar valves, cartilage internal; fixed valve conical, marked only by lines of growth and a ligamental groove; hinge-margin with several deep cartilage-pits ; and one large and prominent tooth on the posterior side; free valve oblique or spiral, thick, perforated by one or more rows of flattened canals, radiating from the umbo and opening around the inner margin; anterior tooth supported by a plate which divides the umbonal cavity lengthwise, posterior tooth obscure; hinge-margin much thickened, grooved for the cartilage. In C. adversa (Fig. 250) the free valve is (6) sinistrally spiral ; its cavity is partitioned off by numerous septa, and divided longitudinally by the dental plate. When young it is attached by the apex of the straight valve (c), but afterwards becomes detached, as the large specimens are found imbedded with the spire downwards. (Saemann.) The lower valve of C. Coquandiana is sub-spiral. * These singular fossils were called ichthyosarcolites by Desmarest, from their resemblance to the flaky muscles of fishes, CONCHIFERA. 451 Fossil, 10 species. Upper Greensand and Lower Chalk. Bohemia, France, Texas. Fig. 251. Internal mould of Caprotina quadripartita, D’Orb., $. u, left umbo; 7, right umbo; J, ligamental inflection; c, cartilage ; ¢,¢', dental sockets a, a', position of adductors; at e, a portion of the third lobe is broken away.* From a specimen collected by Mr, Pratt. CAPROTINA, D’Orbigny. Type, C. semistriata, Pl. XIX., Figs. 13 and 14. Le Mans, Sarthe. Shell composed of two distinct layers; yvalves-alike in struc- ture, dissimilar in sculpturing ; ligamental groove slight ; cartilage internal ; right valve fixed, striated, or ribbed, with one narrow tooth between two deep pits, cartilage pits several on each side of the ligamental inflection, posterior adductor sup- ported by a plate: free valve flat or convex, with a marginal umbo; teeth 2, very prominent, supported by ridges (apophyses) of the adductor muscles (a a’), the anterior tooth cannected with a third plate (nm), which divides the umbonal cavity. The smaller Caprotine occur in groups, attached to oyster- shells; their muscular ridges are much less developed than in the large species (Fig. 251). C. costata is like a little Radiolite. Fossil, 10 species. Upper Greensand, France. (The rest are Chamas, &c.) FamiIty [X.—TRIDACNIDE. Shell regular, equivalve, truncated in front; lgament external; valves strongly ribbed, margins toothed; muscular impressions blended, sub-central, obscure. * The first and fourth lobes, those on each side of the ligamental inflection, appear to be the two divisions of a great internal cartilage, like that of the Radiolite, (Figs 244, 244, c, c.) 452 MANUAL OF THE MOLLUSCA. Animal attached by a byssus, or free ; mantle-lobe extensively united; pedal opening large, anterior; siphonal orifices sur- rounded by a thickened pallial border; branchial plain; anal remote, with a tubular valve; shell-muscle single, large and round, with a smaller pedal muscle close to it behind; foot finger-like, with a byssal groove; gills 2 on each side, narrow, strongly plaited, the outer pair composed of a single lamina, the inner thick, with margins conspicuously grooved; palpi very slender, pointed. The shell of Tridacna is extremely hard, being calcified until almost every trace of organic structure is obliterated. (Car- penter.) TrRIDACNA, Bruguiére. Clam-shell. Etymology, tri, three, dakno, to bite; a kind of oyster. (Pliny.) Example, T. squamosa, Pl. XVIII,, Fig. 15. Shell massive, trigonal, ornamented with radiating ribs and imbricating foliations: margins deeply indented; byssal sinus hii Sar Y So Ly, Dy NN Z yy N NOT QU Fig. 252. Tridacna Crocea, Lam. (Original. ) a, the single adductor muscle; y, pedal muscle, and pedal opening in mantle. Ff, the small grooved foot; 6, byssus: t, labial tentacles; g, gills; J, the broad pailial muscle; between g and 7 is the renal organ; m, the double mantle-margin; s, the siphonal border; 72, inhalent orifice; e, valvular excurrent orifice. An. Nat. Hist. 1855, p. 190. in each valve large, close to the umbo in front; hinge teeth 1.1, posterior laterals 2.1. A pair of valves of 7’. gigas, weighing upwards of 500 Ibs. and measuring about 2 feet across, are used as benitiers in the Church 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 Tridacna, 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. Hippopis, 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, equivalye, 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 line more or less sinuated. Animal with the mantle-margins plaited; siphons clothed with tentacular filaments anal orifice with a tubular valve; branchial fringed; foot long, cylindrical, sickle-shaped, heeled. The cockle (C. edule) frequents sandy bays, near low water; a small variety liyes 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 Deyon the large prickly cockle (C. aculeatwm) is eaten. * “We stayed a long time in the lagoon (of Keeling Id.), examining the fields of corel and the gigantic clam-shells, into which if a man 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 ayiculare, 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. ZL. cymbulare, Lam,. exhibits slight indications of a byssal sinus in the front margins of the valves. Fossil, Hocene, 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 (f/f) 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. C. Caspicum (Monodacna, Hichw.) has a single hinge-tooth, and C. trigonoides (Didacna, EH.) 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 — Southern India. ’ C. Hillanum, Sby. (Protocardium, Beyr.), is the type of a small group in which the sides are concentrically furrowed, the posterior slope radiately striated; the pallial line is slightly sinuated. Jura — Chalk; Europe, India. ConocARDIUM, Bronn. Synonyms, Jiychas, Stein. Pleurorhynchus, Ph. Lunulo- cardium, Minster. CONCHIFERA. 455 Type, C. Hibernicum, Pl. XIX., Fig. 5. OC. aliforme, Fig. 254. - Shell, equivalve trigonal, conical and gaping infront, truncated behind, with a long siphonal tube near the umbones ; anterior Fig. 254. Conacardium 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, like 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. Faminry XI.—Lvcrnipa. 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 haying 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 removing the left valve, and part of the mantle within the pallial line; b-c, the large pedal é opening; the arrows indicate the small plain incurrent orifice, and the valvular excwrrent ori- fice; 7, the foot, contracted in spirit; pp, the large striated. palpi; /, 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, Li. Pennsylvanica, Pl. XTX., Fig. 6. Shell orbicular, white; umbones depressed; lunule distinct; — margins smooth or minutely crenulated; lgament 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. i 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. L. lactea (Loripes, Poli.) has a long contractile anal tube. JL. 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; Hurope — Southern India. — Sub-genera, Cryptodon, Turton. I. 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 CoRBIS, Cuvier, Etymology, corbis, a basket. Type, C. elegans. Pl. XIX., Fig. 8. Synonyms, Fimbria, Muhl. not Bohadsch. ‘‘ Idotzea,’’ Schum. Shell oval, ventricose, sub-equilateral, concentrically sculp- tured ; margins denticulated within; hinge-teeth 2, laterals 2, in each yalye ; pallialline 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 C. dubia (Semi-corbis) Desh., from the Hocene, 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. LHurope. Sportella, Deshayes. Like Sphera, but with 2.1 hinge-teeth. ? Unicardium, D’Orb. (Mactromya, Ag. part.) = Corbula cardioides, Sby. Shell thin, oval, ventricose, concentrically striated ; hgamental plates elongated ; pallial line simple ; hinge with an obscure tooth, or edentulous. Fossil, 40 species? Las — Portlandian. Europe. ? TANCREDIA, 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. 458 MANUAL OF THE MOLLUSCA. DrIPLopontTa, Bronn. Etymology, diplos, twin, odonta, teetn. Synonym, Spheerella, Conrad. Type, D. lupinus (Venus) Brocchi. Pl. XIX., Fig. 9. Shell sub-orbicular, smooth; ligament 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. P 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. fossil, 1 species. Tertiary, Europe. Uneutina, Daudin. Etymology, ungulina, like a hoof. Type, U. Oblonga. Pl. XITX., Fig. 10. Shell sub-orbicular ; ligament very short; epidermis thick, wrinkled, sometimes black; hinge-teeth 2.2; muscular im- pressions long, rugose. Animal with the mantle open below, fringed ; siphonal orifice single; foot vermi-form, thickened at the end and perforated, projecting from the base of the shell or folded up between the gills, palpi pointed; gills two on each side, unequal, the external narrower, with a free dorsal border, inner widest in front. Distribution, 4 species. Senegal, Philippines, excayating winding galleries in coral. ao CONCHIFERA. 459 KEELE Pharun, tole. | 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 yalve. 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 lttle 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. K. rubra is found in creyices of rocks at high-water mark, and often in situations only reached by the spray, except at spring-tides; other species range as deep as 200 fathoms. K. Laperousii (Chironia), Desh. Pl. XTX., Fig. 11, was obtained, burrowing in sandstone, from deep water, at Monterey, California. vs Distribution, 20 species. Norway— New Zealand— California. Fossil, 20 species. Hocene—. 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.) Shelli trigonal, divaricately sculptured ; ligament internal; right valve with 2 lateral teeth, left with 1 cardinal and 2 laterals, Distribution, 8 species, New Ireland, Australia, Philippines. Fossil, 2 species, 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. 18. Shell minute, thin, oblong, anterior side longest; hinge-line notched ; ligament internal, between 2 laminar, diverging teeth (with a minute ossicle. Loven.) Animat with the mantle open in front; margins simple; siphonal orifice single; foot large and broad, grooved. The Montacutce moor themselves by a byssus, or walk freely ; M. 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. LEptTon, Turton. Etymology; lepton, a minute piece of money (from leptos, thin). Synonym ? Solecardia (eburnea), Conrad, Lower California. Type, L. squamosum. 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 Lepton; minutely punctate; ligament internal, oblique; hinge-teeth 1. 2; posterior laterals 1. 2. Distribu- tion, 37 species (?), Philippines, North Australia, Panama. Distribution, 50 species. United States, Britain, Spain. Laminarian and Coralline Zones. fossil, 5 species. . Pliocene—. United States, Britain. a 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; ligament internal; teeth 0.1. Animal with the mantle-lobes united behind and pierced with one siphonal orifice, margins double, the inner with a row of eye-like tubercles; gills large, sub-equal, united behind ; lips large, palpi lanceolate, plaited; foot long, compressed, with a narrow flat sole. The 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 X1II.—CycLapDIp&. 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. Htymology, kuklas, orbicular. Type, C. Cornea, Pl. XIX., Fig. 17. Synonyms, Spherium, Scop. Pisum, Muhlf. (not L.) Mus- eulium, Link. 462 MANUAL OF THE MOLLUSCA. Shell thin, ventricose, nearly equilateral; cardinal teeth 2.1, minute, laterals 1—1: 2—2, elongated, compressed. Animal ovo-viviparous; siphons partly united, anal skortest, 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 branchie, they are few in number and very unequal in size; a full-grown C. cornea has about 6 in each gill; the largest being 4 to 4+ the length of the parent. The young Cyclades and Pisidia are very active, climbing about submerged plants and often suspending themselves by byssal threads; the stziated 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. CyRENA, 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 valve; 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, Muhblf. . C. consobrina, Pl. XIX., Fig. 21. Shell orbicular, concentrically furrowed, epiderrfis polished ; lateral teeth elongated, striated across. CONCHIFERA. 466 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, 105 species. Wealden—. LHurove, United States. ? CYRENOIDES, Joannis. Synonym, Cyrenella, Desh, Type, C. Duponti, 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 XIII.—Cyprinipz. 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. XTX., Fig. 22. * Associated with the bones of Elephas meridionalis, Rhinoceros leptorhinus, Mastodon Arvernensis, Hippopotamus major, ec. 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 yalve; epidermis thick and dark; ligament 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 giils 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. Example, C. corrugata, Pl. XX., Fig. 2. Synonym, Paphia (undulata), Lamarck.* Sheil sub-orbicular, compressed, thick, often sculptured with diverging strie; umbones flat; lunule distinct; ligament nearly concealed; margins smooth; hinge-teeth 3:3; laterals obscure; pallial line entire. Animal (of C. minima) with the mantle open, margins denti- culate, siphonal orifices close together, scarcely projecting, feieed foot large, heeled ; palpi ORE 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. Goodall, Turton. Example, A. sulcata, Pl. XX,, Fig. 1. A. borealis, Fig. 258. ‘(Astarte, the Syrian Venus.) Sheld 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 simple. 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 y’), distinct from adductors ; gills flat, finely striated, destitute of internal partitions; outer Fig. 258. Astarte boreahs, var. semi-sulcata, Leach, 3. Wellington Channel. pill 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, Aigean (80—112 fathoms). Fossil, 285 species. Carb.—. North and South America, Europe, Thibet. ? Digitaria, Wood; Tellina digitaria, Lower Mediterranean. Fossil, Pliocene, Britain. Govupra, C. B. Adams. Shell minute, triangular, furrowed: hinge like Asturte, 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 O—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 on the removal of right valve, and portion of the mantle. In Crassatella pulchra the animal is like Astarte ; foot lingui- form, slightly grooved ; palpi short and broad, few-plaited ; outer gill narrower in front. Rishi Distribution, 34 species. Australia, New Zealand, Philippines, India, West Africa, Canaries, Brazil. Fossil, 64 species. Neocomian —. Patagonia, United States, Europe. TsocarpiA, Lamarck. Heart-cockle. | Etymology, isos, like, cardia, the heart. Type, I. cor. Pl. XX., Fig. 3. CONCHIFERA. AGT Synonyms, Glossus, Poli; Bucardium, Muhlfeldt; Pecchiolia, Meneghini. Shell cordate, ventricese; umbones distant, sub-spiral; ligament external; hinge-teeth 2.2 ; laterals 1—1 in each valve, the anterior sometimes obsolete. Animal with the mantle open in front; foot triangular, pointed, compressed; siphonal orifices close together, fringed; palpi long and narrow; gills very large, nearly equal. Fig. 260 sfsocardza core 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, Hurope, South India. The Isocardia-shaped fossils of the old rocks belong to the genera Cardiomorpha and Tso-arca ; many of those in the Oolites to Ceromya. Casts of true Jsocardie have only two transverse dental folds between the beaks, and no longitudinal furrows. CYPRICARDIA, Lamarck. Example, C. obesa, Pl. XX., Fig. 4. OC. 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 small; gills unequal, the outer narrower and shorter, deeply lamellated, united posteriorly, the inner prolonged between the palpi. Animal of Cypricardia rostrata, Lamarck, Philippines (Fig. and covered with wrinkled epi- : dermis ; siphonal orifices fringed; = \= gills deeply plicated, anterior )) part of the outer gill united to the inner ; dorsal border narrow, plaited ; adductor muscles of two elements, Distribution, 13 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. C. coralliophaga, Lamarck. Shell long, cylindrical, thin, slightly gaping behind; hinge- teeth 2.2, and a laminar posterior tooth; pallial line with a wide and shallow sinus. Distribution, 5 species, Mediterranean, 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. ; Gontophora, 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 ? Cleidophorus, Hall (cast only). Unionites, Wissm. ? Mzeonia, 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, with a small pedal scar close to it, and bounded posteriorly by a strong rib from the hinge; pallial line simple. 300), with mantle-lobes united, ~ ——————— CONCHIFERA. 469 ? Sub-genus. Redonia, Rouault, Bull Soc. Geol., 8, 862. Shell oval, tumid; hinge with cardinal and posterior teeth ; anterior adductor bounded bya ridge. /ossil, Lower Silurian, Brittany, Portugal. (Sharpe.) Fossil, 5 species. Lower Silurian—Trias. United States, Hurope, New South Wales, Tasmania. ? CARDILIA, Deshayes. Type, C. semisulcata, Pl. XVIII., 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. MzGALODON, J. Sowerby. Type, M. cucullatus, Pl. XTX., 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. Fossil, 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. Pacuypbomus (Morris), J. Sowerby. Etymology, pachus, thick, domes, 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 Australia. 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, 5 speeies. 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 ?); hgamental plates short and deep. Opts, Defrance. Example, O. lunulata, Pl. XTX., Fig. 24. (Opis, a name of Artemis.) Shell strong, ventricose, cordiform, obliquely keeled; beaks prominent, incuryed, or sub-spiral; cardinal teeth 1.1; lunule distinct. Fossil, 42 species. Trias—Chalk. Europe. CARDINIA, Agassiz. Etymology, cardo-inis, a hinge. Type, OC. Listeri, Pl. XTX., 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; ligament 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-genus ? 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 Nawtili, 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; palliak line simple. This shell, which is not nacreous inside, is distinguished from any of the Mytilide by the form of its liigamental 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. Tias, Hurope. Shell oblong, thick, yentricose ; 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. Carpira, Bruguiére. Synonyms, Mytilicardia and Cardiocardita (ajar), Bl. Arcinella, Oken. Type, ©. calyculata, Pl. XX., Fig. 5. Hiymology, 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. VY. 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 Venericardie on coarse sand and sandy mud. West Indies, United States, West Africa, Mediterranean, Red Sea, India, China, Australia, New Zealand, - Pacific, West America. O. borealis, Conrad, inhabits the sea of Ochotsk; C. abyssicola, Hinds, ranges to 100 fathoms; (. sguamosa, 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. XVIL., Fig. 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, Hocene, 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 T'rigoniade, to which family it undoubtedly belong SECTION 6.—SINU-PALLIALIA. Respiratory siphons long ; pallial line sinwated. FAmMIty XIV.—VENERIDZ. Shell regular, closed, sub-orbicular, or oblong; lgament external; hinge with usually 3 diverging teeth in each valve; muscular 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 ; branchiz large, 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. N.papma, 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 rubbed, 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 Adgean island, 474 MANUAL OF THE MOLLUSCA. Synonyms, Meretrix, Gray. Dione, Megerle. Cryptogramma, Morch. Examples, C. dione, Pl. XX., Fig. 8. C. chione, Fig. 14, p- 26. Shell like Venus; margins simple; hinge with 3 cardinal teeth and an antenioe tooth a the lunule; pallial sinus moderate, angular. Animal with plain sateen ; siphons united half-way. Distribution, same as Venus, Recent 113 species, Fossil, 80 species. MEROE, Schum. Etymology, Meroé, an island of the Nile. Synonyms, Cuneus (part) Megerle (not Da Costa). Sunetta, Link. Type, M. picta (=Venus Meroé, L. Donax, Deshayes). PT XcXe ie 9. Shell oval, compressed ; anterior side rather longest; hinge with 3 cardinal teeth, and a long narrow anterior tooth; lunule lanceolate ; ligament in a deep escutcheon. Distribution, 11 species. Senegal, India, Japan, Australia, TRIGONA, Muhlfeldt. 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., Fie iit 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; orifices simple; palpi narrow. Distribution, 100 species. Boreal—Tropical seas; low water 80 fathoms. Fossil, 13 species. Carb—. United States, Hurope, South India. Sub-genera, Cyclina, Desh. VY. Sinensis, Chemn. Orbicular, ventricose, margins crenulated, no lunule, sinus deep and angular. Distribution, 10 species, Senegal, India, China, Japan, West America. fossil, 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. Lucinorsis, 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. (Lucina 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 L. decussata, Philippines, a fossil of the English Pliocene, but still living in the Mediterranean. Distribution, 10 species. North America, Norway, Britain. Fossil, 3 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 valve, more or less bifid; pallial sinus deep, rounded, 476 MANUAL OF THE MOLLUSCA. Animal spinning a byssus; foot thick, lanceolate, grooved 3 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. Low 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. Hixample, V. exotica, Pl. XX., Fig. 15. Shell oblong, a little gaping posteriorly, radiately striated. and ornamented with concentric lamelle; three small teeth in each valve; one of them bifid; pallial smus 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. Etymology, petra, stone, colo, to inhabit. Synonyms, Rupellaria, Bellevue; Choristodon, Jonas; Na- ranio, Gray. Type, P. lithophaga, Pl. XX., Fig. 16. P. pholadiformis, PL axes her i. 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, 80 species. United States, France, Red Sea, India, New Zealand, Pacific, West America (Sitka—Peru), Burrows in limestone and mud. Fossil, 20 species. Hocene—. United States, Hurope. GLAUCOMYA (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 yery 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. Toarysiphon, Benson. Differs from Glaucomya in haying the siphons united up to the end. Distribution, 12 species. Hmbouchures of rivers; China, Philippines, Borneo, India. Fossil, 2 species. Tertiary. Hurope. Famity XV.—MAcTRIDA. Shell equivalve, 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 frmged; 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.) Mactra, L. Etymology, mactra, a kneading trough. : Synonyms, Trigonella, Da Costa (not L.), Schizodesma (Spengleri), Spisula (solida), Mulinia (lateralis), Gray. Type, M. stultorum, Pl. XXI., Fig. 1. Shell nearly equilateral; anterior hinge-tooth A-shaped, with 478 MANUAL OF THE MOLIUSCA. 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 moved 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 MW. 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. 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; ligament 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. XXI., Fig. 2. Shell oval, ventricose; valves thick, smooth, eroded; epider= mis olive; cartilage-pit central; hinge-teeth 2; laterals doubled in the right valve, elongated, striated transversely ; 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. (3 other species? Ma- vatlan, 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 im 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. Oitter’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, Hurope. Resembles Mya; burying vertically in sand or mud, especially of estuaries; low water, 12 fathoms. JZ. rugosa, found living 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 from the hinge to the ventral edge. ANATINELLA, G. Sowerby. 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. Mstribution, 3 species. Ceylon, Philippines; sands at low water. Famity XVI.—TELLINIDZ. 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, its 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. Litymology, 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. Engua-felis, Pl. XXI., Fig. 5. T. 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. XX1., Fig. 7. Valves with no posterior fold; lateral teeth wanting. T. carnaria (Strigilla, Turt.) has the ae obliquely sculp- tured; 7’. fabula, Gron., has the right valve striated, the other plain. TZ. Burneti, California, has the right valve flat; 7’. lunu- 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, conyex, 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 valve with obtuse, oblong, transverse teeth ; pallial sinus small; ligament in a narrow groove; cardinal teeth 0.1. PSAMMOBIA, Lamarck. ‘Sunset-shell. Eiymolegy, psammos, sand, bio, to live. Y 482 | MANUAL OF THE MOLLUSCA. Synonyms, Psammotea (zonalis) Lamarck. Psammocola, Bt. Gari, Schumacher. : Fig. 262. Psammobia vespertina, Chemn, 3. Brit. Example, P. Ferroénsis, Pl. XXI., Fig. 9. P. squamosa, Pl, XX, Fig. 10° P. pallida, Fig. 263. Ps yespernmasn 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, Pp, P, pedal muscles. Animal, mantle open, fringed; siphons verylong, 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? Hocene—. United. States, - Kurope. SANGUINOLARIA, Lamarck. Name, from the type, Solen sanguinolentus, Chemn. Synonyms, Soletellina (diphos), Bl. Lobaria, Schumacher. Aulus, Oken. $ AS hig fie Fi, win few © CONCHIFERA. 483 Example, S. livida, Pl. XXII., Fig: 1. 8. diphos, Fig. 2. S. orbiculata, Fig. 3. Shell oval, compressed, rounded in front, attenuated and slightly gaping behind ; hinge-teeth 2, small; siphonal inflec- tion yery deep, connected with the pallial hne; hgament 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 laminze free, dorsal border wide. Distribution, 20 species. West Indies, Red Sea, India, Mada- gascar, Japan; Australia, Tasmania, Peru. Fossil, 30 species. Hocene—. United States, Hurope. SEMELE, Schumacher, 1817. Etymology, Semele, in Greek myth. the mother of Bacchus. Synonym, Amphidesma, Lamarck, 1818.* Type, S. reticulata, Pl. X-XI., 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. Hocene—. United States, Europe. Sub-genera. Cumingia, G. Sowerby. C. lamellosa, Pl. X XI, 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 Caroling. . ; Syndosmya, Recluz. Synonyms, Abra, Leach MS. Erycina (part), Lamarck, 1805.¢ Type, 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 Arycina 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. yw 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 lve buried in sand and mud, but when confined are able to creep up the sides of the vessel with their foot. (Bouchard.) fossil, 6 species. Hocene—. Britain, France. Scrobicularia, Schumacher. Synonyms, Trigonella (part), Costa (not L.), Ligula (part), Mont. ‘‘Le Lavignon”’ (Reaumur), Cuv. lListera, Turt. (not R. Brown). Liutricola, Bl. Mac- tromya, D’Orbigny (not Ag.) Type, 8. 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. MesopEsMA, Deshayes. Etymology, meso, middle, desma, ligament. Synonyms, Eryx, Sw. (not Daud.). Paphia (part), Lamarck, 1799 (see p. 464, note). Erycina (part), Lamarck, 1818 (not Lamarck, 1805, nor Fabr., sinh ‘* 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 striee. ? 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.) ERvILtA, Turton. Lentil-shell. Etymology, ervilia, diminutive of ervwm, the bitter-vetch. Type, KH. nitens, Pl, X X1., Fig. 18. Shell minute, oval, close ; cartilage in a central pit; night 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. —250 fathoms. Donax, L. Wedge-shell. Hxample, D. denticulatus, Pl. XXI., Fig. 19. Ltymology, donax, a sea-fish. (Pliny.) Synonyms, Chione, Scop. Cuneus, Da Costa. Capisterium, Meuschen.* lLatona and Hecuba, Schum. LEHgeria, 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, alk tropical seas. In sands near low-water mark (—8 Lars) 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.” Adiste 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. ventricose, Deshayes, is rayed like Galatea, and has its beaks eroded. ? Isodonta (Deshayesii). Buy. Bull. Soc. Geol. Oolite. France, England. GALATEA, Bruguieére. Synonyms, Egeria, Roissy. Potamophila, Sowerby. Mega- desma, Bowdich. Type, G. reclusa, Pl. XXI., 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—S 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. Famity XVII.—SoLENIDz. Shell elongated, gaping at the ends; lgament external; hinge-teeth usually 2.3, compressed, the posterior bifid. External shell layer with definite cell-structure, consisting of long prisms, yery 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, S. siliqua, Pl. XXII., Fig. 4, CONCHIFERA: 487 Synonyms, Hypogeea, 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. 4+; 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. Htymology, 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, Pl. XXII, Fig. 6. Shell narrow, sub-equilateral, anterior adductor 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. Jossil, 3 species. Pliocene—. Italy. Machera, Gould. (Siliqua, Megerle. Leguminaria, Schum.) M. polita, Pl. XXIT., 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. WM. costata, Say, is 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. SoLEcuRTUS, Blainville. Hiymology, solen and, curtus, short. Synonyms, Psammosolen, Risso. Macha, Oken. Suliquaria, Schum. Tagelus, Gray. Examples, 8. strigilatus, Pl. XXII., Fig. 8. 8. Caribzeus, Pl. XXII, Fig. 9. Shell elongated, rather ventricose, with sub-central beaks ; margins sub-parallel; ends truncated, gaping ; ligament promi- nent ; hinge-teeth 2; 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, Madeira. Fossil, 30 species. Neocomian—. United States, Hurope. - CONCHIFERA. x 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. J)istribution, India, China. In the mud of river-estuaries. Famity XVITI.—Myacipz. 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. Fig. 265. Mya truncata, L. 4. Brit. (after Forbes.) Mya, L. Gaper. Hiymology, myac (-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. ossil, 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 148 Y3 490 % MANUAL OF THE MOLLUSCA. fathoms. Jf. arenaria burrows a foot deep; this speciesand 2, - 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 Pholademya. CorrRULA, Bruguiére. Etymology, corbula, a little basket. Type, C. sulcata, Pl. XXITI., Fig. 2. Synonyms, Erodona, Daud. (=Pacyodon, Beck.) Agina, Turt. Shell thick, inequivalve, gibbose, closed, produced posteriorly ; nght 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 fringed ; anal valye tubular; foot thick and pointed; palpi moderate ; gills 2 on each side, obscurely striated. | Distribution, 66 species. United States, Norway, Britain, Mediterranean, West Africa, China. Inhabits sandy bottoms; lower laminarian zone—80 fathoms. Fossil, 120 species. Inferior Oolite—. United States, Hurope, 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, Hocene, 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. §S. Binghami, Pl. XXIII., Fig. 4. Shell CONCHIFERA. 491 oblong; right valve with a curved, conic tooth in front of the 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 10—25 fathoms. fossil, 20 species. Tertiary. Europe. NERA, Gray. Etymology, Necera, a Roman lady’s name. Type, N. caspidata, Pl. XXTII., 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, Mediterranean, 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. Litymology, 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. XXTII., Fig. 11. Shell sub-orbicular, ventricose, thin, translucent, 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. PaNnopma, Menard de la Groye. Etymology, Panope, a Nereid. Example, P. Americana, Pl. XXII., 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 grooyed 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 Sawicava; the animal itself is like a gigantic Saxicaya. (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 ee: P. g'ycimeris attains a length of 6 or 8 inches. CONCHIFERA. 493 Fig. 267 represents the animal of Panopeea glycimeris, as seen on the removal of the left valve 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 (0), with a prominent heel ; pallial muscle (m) continuous ; with aGeep siphonal inflection (s); lips broad and plain, palpi triangular, deeply plaited (¢); 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. Panopea Glycumerss 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 MOLLUSCGA. Shell oblong, gaping at each end; posterior side shortést; 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 ; Mf SQW hy Fig. 268. Glycimeris siliqua, Chemn. Newfoundland. a a, adductor muscle; p, pedal muscle; s, siphonal muscle; f, foot; ¢, 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. FAMILY X1X.—ANATINIDZ. Shell 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; pallia 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. UONCHIFERA. 495 ANATINA, Lamarck. Lantern-shell. _ Type, A. rostrata, Pl. XXIIT., 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-equivalve, 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 valve, 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, 560 species. Devonian ?—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. Distrihutton, West Indies, South America. Cochlodesma, Couthouy. CO. preetenue, Pl. XXIII, Fig. 8. (Bontia, Leach MS. Ligula, Mont., part.) Oblong, compressed, thin, slightly inequivalve ; 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 furrow into two parts, the dorsal portion bemg narrower, com- posed of a single lamina only, and attached by its whole inner surface. (Hancock.) Distribution, 2 species. United States, Britain, Mediterranean. fossil, Pliocene, Sicily. Cercomya, Agassiz. C. undulata, Sowerby. (—Rhynchomya, Agassiz.) Shell very thin, elongated, compressed, attenuated posteriorly ; sides concentrically furrowed, umbones fissured, posterior (cardinal) area more or less defined. fossil, 12 species. Oolite—Neocomian. Europe. Tract (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, slightly compressed, 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, nucleatza 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 J’. distorta, Mont., are found in the crevices of rocks, and burrows of Saxicuva ; they have been mistaken for boring-shells. Distribution, 17 species. Greenland, United States, Norway, Britain, Mediterranean, Canaries, China, Sooloo; 4—110 fathoms. Fessil, 36 species. (Trias?) Lower Oolite—. United States, Europe. PHOLADOMYA, G. Sowerby. Recent Type, P. candida. Pl. XXII., Fig. 15. - 1. Tortola. Shell oblong, equivalve, veutricose, gaping behind; thin and translucent, ornamented with radiating ribs on the sides; lga- ment external; hinge with one obscure tooth in each valve; pallial sinus large. Animal with a single gill on each side, thick, finety 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, Kurope, Algeria, . Thibet. | Homomya (hortulana), Agassiz. Shell thick, concentrically furrowed, without radiating ribs; 12 species. Oolites, Europe. Tyleria, Adams. Cartilage inserted in a spoon-shaped hollow; interior of shell with a layer of carbonate of lime between the spoon-shaped hollow and the anterior edge. Myacitss (Schlotheim), Bronn. Synonyms, Myopsis (Jurassi), Agassiz. Pleuromya, Agassiz. Arcomya (Helvetica), Agassiz. Mactromya (mactroides), Ag. Anoplomya (lutraria), Krauss. Example, M. sulcatus, Fleming. (Allorisma, King, Pal. Tr., 1850, Pl. XX., Fig. 5.) 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, Hurope, South Africa. Sub-genera ? Goniomya, Agassiz. Mya literata, Pl. X-XIT., - Fig. 16. (Lysianassa, Minster, not M. Edwards.) Shell equi- valve, thin, granulated; ligament external, short, prominent. Fossil, 33 species. Upper Lias—Chalk, Hurope. Tellinomya (nasuta), Hall; Silurian, United States, Hurope. 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‘Ooy.. Shell thin, ventricose, concentrically furrowed in front ; escutcheon long and flat. Silurian—Carb. Hurope. 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. tymology, keraos, horned, mya, mussel. Type, C. concentrica (Isocardia) Sowerby, Min. Con. 491, Hig. 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? Hurore. Sub-genus ? Gtresslya(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. Jias—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, HK. sulcata, Ph. (T. Pal. Soc. 1850, Pl. XX., Fig. 5.) Carb. Britain. Synonyms, Allorisma, King (part). Sanguinolites, M‘Coy (part). Shell oblong, equiyslve, thin, concentrically striated, close; umbones anterior; lgamental grooves narrow, external ; hinge-line thin, edentulous, furnished with large oblique cartilage plates, placed beneath the umbones, and leaying space for an ossicle? or the plate may be equivalent to the sub-um- bonal blade in Pholas ; pallial line simple ? Fossil, 4 species. tha. —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, Li. 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. CONCHIFERA. 499 Fossil ? Miocene—. Europe. (100 species. Lower Silurian—. D’Orbigny. ) ? Entodesma (Chilensis), Phil. Shell thin, saxicava-shaped, slightly inequivalve and gaping, covered with thick epidermis ; hinge edentulous; each valve with a semicircular process con- taining the cartilage. PanporA (Solander), Bruguieére. Type, P. rostrata, Pl, X-XII., Fig. 11. (Pandora, the Grecian Hye.) 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. MyYapora, Gray. Type, M. brevis, Pl. X-XIII., 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 like Anatina ; outer cells large, rather prismatic. Distribution, 10 species. New Zealand, New South Wales, Philippines. Myocuama, Stutchbury. Type, M. anomioides, Pl. XXIII., 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-lke 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 506 MANUAL OF THE MOLLUSCA. surrounded by separate areas ; siphons distinct, unequal, small, shightly 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-hke; 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, Cleidothzerus, Stutch. Shell inequivalve, 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.—GASTROCHANIDA. 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 twhicalide 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. GASTROCHANA, Spengler, 1783. Type, G. modiolina, Pl. XXIII., Fig. 15. (Guster, ventra', cheena, gape.) Shell regular, wedge-shaped, umbones anterior; gaping widely in front, close behind; lgament 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. 15a. 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. XXIII., Fig. 16. (= Fistulana clava, 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 diaphragm behind the valves. Distribution, 3 species. Madagascar, India, Philippines, Australia; burrowing in sand or mu¢. Fossil, Inf. Oolite—. United States, Europe, Southein India. SAXICAVA, Bellevue. Etymology, saxwm, stone, cavo, to excavate. SS. rugoca, PIOXXE., Fig. 13. 502 MANUAL OF THE MOLLUSCA. Synonyms, Byssomya, Cuv. 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 byit. Its crypts are sometimes 6 inches deep (Couch); they are not quite symmetrical, and like those of the Lithedomus, 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 Hurope and in the United States, and in all the glacial deposits. CLAVAGELLA, Lamarck. Example, C. bacillaris, Pl. X XTIIL., 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 contral 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. 5038 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 Suwicava or Petricola beside the loose valve of the Clavagella, into whose tube they.must have entered after its death. 0. elongatw 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, Pl. X-XIII., 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) rufiles. 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, Java, 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. Faminy 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 valves; 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 hgament. The Pholadide perforate all substances that are softer than their own valves (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; Teredina cements its valves 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 epitheihum; 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. PHOLAS, L. Piddock. - _ Hiymology, pholas, a.burrowing shell-fish, from pholeo, to bore. Synonyms, Dactylina, Gray. Barnea, Risso. Type, P. dactylus, Fig. 269. Example, P. Bakeri, Pl. XXIII., 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. 311.) 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 dwarted 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. ———— CONCHIFERA. 505 The commun 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 is 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- Hie | 269. Pholas iene Chalk, Sussex Coast. u, umbonal valves; p, 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, L. (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—) Hocene—. United States, Europe. The secondary species belong to the next group. PHOLADIDEA, Turton, 1819. Pype, P. papyracea, Pl. X XII1.; 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 valves. 11 species. West Indies, Africa, India. Jf. striata burrows in hard timber. a 506 MANUAL OF THE MOLLUSCA. If. terediniformis was: found in cakes of floating wax on the coast of Cuba. (G. B. Sby.) JZ. australis in (fossil F) resin, on the coast of Austraha. JM. rivicola in timber twelve miles from the sea, in Borneo. JM. scutata, Hocene, 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 deve- 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. /ossil, Miocene —. France. Parapholas, Conraé, P. bisulcata, Pl. XXTIT., Fig. 22. Valves with 2 radiating furrows. Distribution, 4 species. Panama, Torres Straits. XYLOPHAGA, Turton. Se, euion, wood, phago, to eat. Types, X. incertae, Pl. XXII, 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 slerder con- tractile siphons, which are furnished with pectinated oe and divided at the end; foot thick, very extensile. Distribution, 2 encemee. Norway, Britain, South ae 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. XXIII., Figs. 26, 27. Synonyms, Septaria, Lamarck. UHyperotis, Guettard. S 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 furrow ; 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 front, with a minute pedal opening; foot sucker-like, with a foliaceous border; viscera included in the valves, heart not pierced by the intestine; mouth with palpi; gilly 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 verry eV PEEP ay) UE WAU pire ne ncn! LO yy RTL) Fig. 270. Ship-worm, Teredo Worvegica, 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 haye 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. LLias—. United States, Hurope. Sub-genus. Teredina, Lamarck. T. personata, Pl. XXIIT., Figs. 24, 25. Eocene, 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 contracted by a lining which makes it hour-glass shaped, or six-lobed (Fig. 26 a.). * The operations of the Teredo suggested to Mr. Brunel his method of tunnelling the Thames, INDEX. The synonyms are printed in italics, and the pages where the genera are described ars Abbreviations, 49. Abra, 483. Abralia, 171. Acanthina, 223. Acanthochites, *284. Acanthodoris, 3 Bo2. 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. Acmea, #281. _Acmaed, 311. Acme, 3ll. Acceli, *174. _dcosted, 435. _Acroculia, 277. Acroloxus, 302. _Acrotreta, #590. Acte@on, 313, 339, Acteonelia, *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. Afgean Sea Shells, 67. AMgirus, 327, *330, AENIgMa, ae Ev lide, *3 ZEolis, 328, — ZEstivation, 13, /Etheria, #435. Affinities, 45. indicated by an asterisk (*). African region, 97. Aganides, 196. Agaronia, #227. Agina, 490. Alasmodon, 433. Alcadia, #310. Alcynus, 265. Alderia, *338. Aleutian province, 76. Alexia, #305. Alicula, 3516. Allorisma, 496, 498. Alvania, 240. Amalthea, *278. Amalthei, *193. Amathina, *277. Ambonychia, *417. Amicula, 284. Ammonites, 35, 37, *197. Ammonitidee, #195. Amnicola, *247. Amoura, 239. Amphibola, *259. Amphibulima, 290. Amphiceras, 234. Amphichena, *486. Amphidesma, 451, 483, 497. Amphidonta, 407. Amphipeplea, *301. Amphisphyra, *317. Amphorina, 335. Ampulina, 236. Ampullacera, 259. Ampullaria, 14, 27, 52, #208. Ampuitina, 310. Amusium, 411. Amusium, #412. Anadenus, *296. Analogies, 45. Anapa, *485. Anastoma, *289. Anatina, *495. . 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. Apnoceras, 193. Apleza, 302. Aploceras, 194. Aplustrum, *318. Aplysia, 11, 22, 23, 24,*320. Aplysia, 321. Aplysiadee, *3520. Aporrhais, 211, *244. Aptychus, 182. Aquiferous system, 24. Arabian shells, 98. Aralo-Caspian prov., 68. Arca, 80, 395, #424, Arcadee, #424. Architectoma, 253. Arcinella, 437, 471, 502. Arcomya, 497. Arctica, 464, Arctic province, 57—59. Areopagia, 480. Argentine region, 114. Are ciope, *368. Argonauta, 28, 31, 39, 56, PGT oa Argus, 411. Arietes, *198. Arion, #296. Ariophanta, *290. Armati, *198. Artemis, *474. Articulated operc., 208. Ascoceras, 189. Asiphonida, 406. “Asolene, *259. Aspergillum, 55, *503. Assiminea, 256. Astarte, 33, 55, *464, _ Astartela, 469. Asteronotus, *329. Atagema, *329. Athoracophorus, 297. Athyris, *373. Atlanta, 29, 341, *344. Atlantide, *343. Atlas, *320. Atrypa, *378. Aturia, *189. Atys, 316. Aucella, *416. Aulonotreta, 392. Aulopoma, 308. _Aulosteges, #385. Aulus, 482. Auricelia, 805. Auricula, *304. Auriculide, 36, *303. Auriscalpium, 495. Australian region, 103. Austraiian shells, 74, Avellana, 314. = Avicula, 80, *415. Aviculide, *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. Balantium, 349. Balea, *293. Balearic Isles shells, 92, Baphia, 433. Barbatia, 424. Barnea, 504. Base of shell, 206. Baiillus, 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. Berthella, 322. Bezoardica, 224, Biapholius, 502. Bifrontia, *253. Biradiolites, *448.. errr — INDEX. Birostrites, 447. Bithynia, 33, *258. Bittium, *242. Black Sea shells, 67. Body whorl, 206. Bolitena, *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. Buecinum, 55, *219. Buchanania, *299, Buckie, 218. Bulimulus, *291. Bulimus, 15, 32, 36, 37, 44, 111—118, *291. Bulin, 301. Bulinus, 291. Bulla, *316. Bulla, 315. Bullea, 318, Bullia, 220. Bullide, *815. Buillina, 317, 318. Bullinula, 318. Bursatella, 321. Lusiris, *821. T-ysso-anodonta, 434, J'ysso-arca, 424, Byssomya, 502. | Byssus, 19, Cecum, *249. Calcar, 264. Calearella, *284. Calceola, *883. Californian province, 78. California, shells of, 109, Callia, 309. Calliopza, *336. Callo-chiton, 283. Callopoma, 263. Calma, *337. Calpurna, *234. Calpurnus, 234, Calypeopsis, *276, Calyptreea, *276. Calyptreeide, *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. Cajyisterium, 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. Carinaria, 9, 12, 29, 341, *343, Carinaroides, 343. Carocolla, *289. Carolia, *410. Cartilage, 400. Carychium, “308, Casella, *332. Cassiani, *199. Cassidaria, *225. ‘assidula, 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, 285. . Cephalopoda, 4, 27, 155. Cephalopoda, range in time, 127. Ceratisolen, *487. Ceratites, *197. Ceratosoma, *331. Cercomya, *495. 510 Ceriphasia, *247. Cerithiadee, *242. Cerithidea, 36, *243. Cerithiopsis, *242 Cerithium, *242. Cernina, *236. Ceromya, 467, *497. Ceronia, *485. Cerophora, 342, Ceylonese shells, 100. Chena, *501. Chalidis, 340. Chama, 38, 131, *437. Chamide, *437. Chamostrea, *500. Cheiroteuthis, *170. Cheletropts, 212, 352. Chelidonura, *319. Chemnitzia, *239. Chenopus, 245. Chili, shells of, 114. Chilinia, *3801. Chilostoma, *247. Chinese snails, 101. Chione, 473, 485. Chioreera, *338. Chironia, 459. Chiton, 23, 28, *282. Chitonellus, *28+. Chitonide, *282. Chlorostoma, 264. Choanopoma, *307, 308. Chondropoma, 307. Chondrosepia, 168. Chonetes, *326. Choristites, 371. 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, *271. 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. Clerdophorus, 468. Cleidotherus, 500. Cleiothyris, 373, 378. Clementia, *475. Cleobis, 469. Cleodora, 347, *349. Clepsydra, 503. Cliidze, *353. INDEX. Climate, inf. of,on dist.,53. Clio, *353. Clio, 349. Cliodita, *353. Cliona, 34. Clone, 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, 34. Collecting shells, 136. Collonia, *266. Colour of shells, 38. Columbella, 55, *226. Colurhbian 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. Corbis, *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. Craniadee, *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. Cuittle 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. Cyctostomide, *306. Cyclostrema, *266. Cyclothyris, 375. Cyclotopsis, 308. Cyclotus, *308, Cylichna, *317. Cylindra, *231. Cylindrella, 36,.*293. Cylindrites, *313. Cyllene, *221. Cymba, 28, #231. Cymba, 278. Cymbiola, 230. Cymbulia, *351. Cymodocea, *354. Cynodonta, 216. Cypreea, 12, 24, 32; 55, 37, 55, *232. Cyprecassis, 24a Cypreeida, *23°. Cypricardia, *463 Cypricardites, 422, 468. Cyprina, 33, 55, *463. Cyprinidee, *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. -Dayidsonia, *382. Davila, *485. Decapoda, *166. Decollated shells, 36, 206. Defrancia, 229. ~ Delphinoidea, 256. Delphinula, 266. Delthyridea, 365. Delthyris, 371. Dendrodoris, 328. Dendronotus, 827, *334. Dendrostrea, 408. Dentaliade, *282. Dentalium, 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. 2 Discina, 357, *388, Discinide, *388. Discites, *189. Disciées, 411. Discohelix, 253. Discosorus, *193. Dispotea, 276. Dithyra, 393. INDEX. Ditremaria, 271. Dolabella, *321. Dolabra, 431. Dolabrifera, *521. 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. Eichinospira, 285. Edmondia, *498. Hgeria, 485, 486. Eggs, 40. Eylusia, 248. Fiidothea, 319. fllasmatina, 294. Electrina, 310. Eledone, 27, *165. Elenchus, 12, *265. Elysia, *339. Elysiade, *339. Emarginula, *275. Embla, 491. Embletonia, *336. Embryo, 44. Encephala, 3. Endemic species, 51. Endoceras, *192. Eindosiphonites, 190. Enida, 265. Enoplo-chiton, 284 . Enoploteuthis, *171. Ensatella, 487. Ensis, 487. Enieletes, 380. Entodesma, *499. Enzina, 214. Eolis, 23, 40. Epidermis, 33, 400. Epiphragm, 288. LH pithyris, 363. Erato, *234. Erodona, 490. Ervilia, *485. Erycina, 459, 473, 483, 484. Eryx, 484. Escutcheon, 400. Fubranchus, 335. Eucharis, *492. Eudesia, 365. Hulima, *240. Eulimella, *239. Foumenis, 334. Euomphalus, 36, *267, 346. FZuphemus, 344. Euplocamus, 331. Eurybia, *350. Eurydesma, *417. Eurydice, 338. Huthria, 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, 31. Ficula, 217. Filurus, *387. fimbria, 333, 457. Fimbriati, *199. Fiona, *336, Firola, 9, 341, *342. Firolidee, *342. Firoloides, *342. Fisstrostra, 365. _ Fissurella, 27, *272. Fissurellidee, *272. Fissurellidxa, *273. Fistulana, 35. 501. Flabellina, *335. Foed, 8, 9. Formation of shells, 34, Forms of shells, 36. Fossarus, 131, *253 fragilia, 481. Fryeria, *525. Fucola, 339. Fulgur, *217. Funnel, 187. Fusulus, 2938. Fusus, 29, 35, 37, *218. Frusus, 212. Gadinia, *281. Galapagos Islands, 112. Galapagos Isles shells, £Q, Galatea, *486. Galeomma, *461. Galerus, 276. Galvina, *537. Ganglia, 16. Gari, 482. Gasteropoda, 4. Gasteropoda, time, 128. Gastrana, “481. Gastrana, 476. Gastridium, 219. Gastrocheena, *501. Gastrocheenidee, *5CC. Gastroceeli, *174. Gastroplaz, 323. Gastropteron, *319 Gellina, 334 Gena, *267. range in 512 Genera, 46, 52. Generic areas, 52, 53. Genetic aflinity, 45. Geographical dist., 50. Geological strata, 118. Geomalacus, *296. Geomelania, *311. Geoteutisis, *168. Geotrochus, *289. Geovula, 304. Germanic region, §9. 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, *195,. Gonambonites, 380. Gonatus, *168. Goniatites, *196. Gonioceras, 190. Goniodoris, *3830. Goniomya, *497. Goniophora, 468. Goodallia, 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, *333. Gypidia, 377. Halia, *220. Haliotide, *268. Haliotis, 24. 27, *268. Halobia, 417. Halopsyche, 350. Haminea, 316. Hamites, *201. Hamulina, 201. Harpa, 55, *226. Tajpila, 230. Harvella, *478. Hastati, *174. Head, 42. Heart, 24, 42. Hectocotyle, 159-163, Flecuba, 485. Heicion, 278. INDEX. Helicarion, 290. Tielicella, *289. Helicerus, *178. Helicide, #288. Helicina, *800. FAlelicina, 265. Helicoceras, *200. Helicocryptus, 253. Flelicolimar, 290. Heliconoides, 352. Helicophanta, 290. ffelicophlegma, 344. Hlelicteres, 292. Ffelisiga, 290.. Helix, 11, 14, 33, 35, 37, *288. Helix distribution, 87. Helminthochiton, 284. Hemicardium, *454. Hemicyclonosta, 469. Hemidoris, 328. Hemimitra, 247. Hemipecten, *412. Hemiplacuna, 410. Hemipronites, 389. Hemisinus, *247. Hemithyris, 375. Hemitoma, #274. Heptabranchus, *329. Hermea, 338. Heteroceras, *200. Heterofusus, 352. Heterogangliata, 2, Heterophylh, 199. Heteroteuthis, 170. Hettangia, 457. Hexabranchus, *329. Fiiantula, 273. Fiatella, 461, 502. Hinge line, 401. Hinnites, #412. Tippagus, 472. Hipparionyz, 378. Hiippochrenes, 212, Hippomya, *425. Hipponyx, 7, #278. Hippopodium, *471. Hippopus, *453. Hippurites, 32, *443, Hippuritidee, *440. Fiirundinella, 319. Histioteuthis, *170. Holopea, *272. Holostomata, *234, Homoganegliata, 2. Homoiozoic belts, 54. Homologies of shell, 39. Homomya, *496. Hoplomytilus, *425. Hortolus, 189. Humphreyia, *503. Huronia, *191. Hyaleea, *348. Hyaleidz, *348. Hyalina, *252. Hyaloteuthis, 172. Hybernation, 39, 40. Hybocystis, *509. Hybrids, 46. 1 Hydatina, 318. Hydrobia, *256. Hydrocena, 307. Hyolites, 191. Fyperotis, 506. Hypobranchea, *325. HHypodema, 383. Aypogea, 487. Hypostoma, *289. Hypothyris, 375. Hypotrema, *418. Hyria, *434. Hysterolites, 379. Tanthina 23, 31, *271. Icarus, *322. Ichthyosurcolites, 450. Idalia, *331. Idotaa, 457. Imbricaria, *231. Imbricated operc., 207. Imperator, *264. Imperforate shells, 205. Impregnation of egg» 41. Incilaria, *296. Indian region, $9. Indo-Pacific province, 71. Infero-branchia, 312. Infundibulum, 264, 276. Thnk bag, 157, 173. Tnoceramus, 31, #419. Inoceramus, 491. Inoperculata, 285. Integro-pallialia, #436. Io, 247. Iphigenia, *486. Ischnochiton, 283. Isidora, 301. Ismenia, *368. Tsoarea, *427, 467. Tsocardia, *466. Isocardia, 431. Isodonta, 478, 486. Lsegnomon, 418. Ttieria, 314. Jamaica, shells of, 110. Jamaicia, 307. Jaminea, 239. Janella, *297. Janus, 337. Japanese snails, 101. Japonic province, 75. Jasoniila, 285. Javanese shells, 102, Jeffreysia, *256. Jouannetia, *o06 Kaleno, 175, Katharina, #284. Kellia, #459. Kingena, *368. Kleinella, *317. Koninckia, *381. Kraussia, *367. Labio, 265. Lachesis, *229, } Lacuna, 55, *255. Ladas, 344. Levigati, *189. Lagena, 216 Lajonkairtia, 475. Lamellaria, *237. Lamellibranchiata, 5, 393. Laminarian zone, 151. Lampania, *244, Lanupas, 363. Land provinces, 51. Laniogerus, 336. Thanistes, *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. Letodomus, 220. Leiostoma, 218. Lembulus, 427. Leonia, 306. Lepeta, *281. Leptena, 380, 381. Leptagonia, 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. Limacella, 296. Limacide, *295. Limacina, *351. Limacinide, *351. Limeea, *413. Limanomia, *409. Limapontia, *340, TLimatula, *413. Limax, *295. Limnea, *300. Limneeidee, *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. Littorinide, *250. Lituites, *189, Lituus, 174. Liver, 22. Livona, 264. Lobaria, 482. Lobiger, *322, Loligo, “167. Loligopsis, *170. Laligosepia, 168. Loliolus, 168, 172. Lomanoius, *334. Lomastoma, *309. Lophocercus, 222. Lophurus, 283. Loripes, 456. Lottia, 281. T.oxonema, *241. Lucapina, *273. Lucidella, *310. Lucina, 38, 56, *456. Lucinidee, *455. Lucinopsis, 131, *475. Lunatia, *236. Lunularea, *427. Lanulocardium, 454. Luponia, *233. Lusitanian region, 91—97. Lusitanian prov., 63, 67. Lutraria, *479. Lutricola, 484. Lychas, 454. Lychnus, *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. Meonva, 468. Magas, *366. Magdala, 498. Magellanica, 365. Magellanic province, 82. Magilus, 36, *224. Zo 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 IMarinula, 304, Marisa, *259. Marmorostoma, 263. Marsenia, 237. Martesia, *505. Martinia, 371. Mauritius shells, 99. Mediterranean shells, 65. Medoria, 255. legadesma, 486. Megadesmus, 470. Megalodon, *469. Megaloma, *469. Megalomastoma, 309. Meganteris, *365. Alegasiphonia, 189. Megaspira, 286, *294. Megathyris, 368. iegatrema, 278, Megerlia, *367. Ifeghimatium, 296. Meladomus, *259. Melafusus, *247. ° Melampus, 804, Melanatria, *247, Melania, *246. Melaniade, *246. Melantotdes, 240. Melanopsis, 338, 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. Ifiranda, 331. Mitra, 53, *231. Mitrella, 231. Modiola, 11, 33, *421. Modiolarea, *422. Modiolaria, 422. Modiolopsis, *422. Modulus, *252. Molluscoida, 5, 6. Alonilea, 264. o14 Monoceros, *223. Monocondylea, *454. Monodaena, 454. Monodonta, *265. Moneecious, 40. Monomyary, 402. Monopleura, *438. Mono-pleuro-branchiata, 312. Monoptigma, *240. Monoptigma, 239. Monoptygma, 313. Monotis, *417. Monstrosities, 37. Montacuta,*460. Montagua, 335. Mopalia, 284. Morio, 225. Morrisia, *367. Morum, 225. Mouretia, 281. Mulinia, 477. Mulleria, 432, *435. Multispiral operc., 208. Munsteria, 182. Murchisonia, *270. Murex, 23, 35, 36, *213. Muricide, *212. Muscular system, 18, 355, 401. Musculium, 461. Mutela, 435. Mya, *489. Myacide, *489. Myacites, *497. Myadora, *499. Myalina, *421. Myatella, 498. Mycetopus, *435. Mycetopus, 435 Myochama, #499. Myoconcha, *471. Myonia, *241. Myoparo, 427. Myophoria, *431. Ayopsis, 497. Myrina, #423. Myristica, *217. MMysia, 475. Myllita, 459. Mytilicardia, 471. Mytilide, *420. Mytilimeria, *422. Mytilomya, 425. Mytilus, 30, 31, 45, *420. Myxostoma, 308. ANacca, 235. Nacella, *280. Nacreous shells, 29. Nanina, 290. Naranio, 476. Narica, *237. Nassa, *221. Natica, 38, #23 35 Naticella, 23 36. Naticide, *OB5. Naticina, *236. Naticopsis, *235, INDEX. Natural barriers, 55. Naiural history provinces, 50—54. Nautilide, *185. WVautiloceras, 194. Nautilus, 161. Nautilus, 55, 185. Navicella, *262. Nezra, *491. Neda, *323. Nelo, 429. Neithea, *412. Nematura, *256. Nerinza, *244, 314. Nerinella, *244. Nerita, 38, 55, *260. Neritidz, 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, Noetia, 427. Nomenclature, 48. Northia 221. Notarchus, *321. Nothoceras, *195. Notocceli, *174. Notomya, 469. Novaculina, *489. Nucinella, 427. WNucleobranchiata, 340, Nucleus, 205. “Nucula, *426. Nucula, *497. Nuculina, *427. Nucunella, 427. Nudibranchiata, *825. Obeliscus, 238. Obolus, *392. Octopoda, *158. Octopodoteuthis, 171. Octopus, 56, *163. Ocyzhoe, 161, Odoneimetus, 495. Odontidium, 249. Odontostomus, *291. Odostomia, *239. Oleacina, 292 Oligyra, 310. Oliva, 82, 55, *227. Olivancillart 1A 22. Olivella, *227. Olivia, 265. Omala, 480. Omalazxis, 253. Omalia, 475. Omalonyx, *291. Ommastrephes, *172. Omphalotropis, 507. Oncidiade, *299. Oncidium, *299. Oncidoris, *329. Oncoceras, *193. Oniscia, *225. Onustus, 254. Onychia, 171. Cnychochi‘on, 284. Oxychoteu his, *171. Operculata, *305. Operculum, 38, 182, 237. Ophileta, 267. Opis, *470. Opistho-branchia, *311. Opisthophorus, *309. Orbicelia, 389. Or bicula. 358, 386, 388. Orbrculoidea, 388. Orbis, *253. Orbulites, 187. Oregon, shells of, 109. Ormoceras, *191. Ornati, *198. Orthambonites, 380. Orthide, +379, Grthis, #380. Orthisina, *380. Orthoceras, 38, *190. Orthoceratidee, *190. Orthona, 336. Orthonotus, *423. Orthothriz, 385. Oscanius, 322. Osteodesma, 495. Ostrea, 31, *407. Ostreidee, *407. Otina, *238. Otolithes, 17. _ Otopoma, *307. Oviducts, 359. Oviparous repr., 40. Ovulum, 27, *234. Ovum, 41. Owenia, 169. Oxygyrus, *344. Oyster shell, 31. Pachydomus, *469. Pachylabra, 258. Pachymya, 492. Pachyodon, 434, 470. Pachyotis, 291. Pachyrisma, *470, FPachytes, 414. Pachytoma, 310. Pacyodon, 490. Padoillus, 268. Pagodella, 252. Patleoteuthis, 177, 182. Pallial impression, 20. Pallial line, 404. Pallial sinus, 404. Pallio-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. Pandora, *499. Pandorina, 498. Panopeea, 53, *492. Paphia, 464, 465, 475, 464. Papuan shells, 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. Patellidee, *278. Patelloidea, 281. Patina, 280. Paucispiral operc., 207. Paxillus, *294. Pearls, 30, 433. fecchiolia, 467. Pecten, 8, 29, 38, *411. Pectunculina, 426. Pectunculus, *425. Pedalion, 418. Pedicularia, *223. Pedipes, *304. Pedum, #414. Pelagella, *332. Pelagia, *354. Peilli-branchiata, 359. Peloris, 407. Peilta, 290, 323. Peltella, 297. Pen, 178. Pentamerus, *377. Peplidium, 331. Feracle, 352. Periostracum, 33, Periploma, *495. Peristome, 206. Perna, 55, *418. Peroneda, 480. Perotis, 170. Persian Gulf shells, 73. Persicula, 232. Persona, 214. Peru, shells of, 113. Peruvian province, 81.. Petal iconchus, *249. Petricola, 476. Pfeifferia, *290. Phanera-pneumona, 305. Phanerophthalmus, *316. Phanerotinus, *267. Pharella, *488. Pharus, 487. Phasianella, *263. Phasianema, 253. Philine, 10, *818. Philippia, 253. Philippine Island snails, 101. Philomycus, 296. INDEX. Philonexis, *165. Phlebenterata, 339. Pholadidze, *503. Pholadidea, 35, *505. Fholadomya, 454. Pholadomya, *496. Pholadopsis, 506. Pholas, 28, 102, *504. Phorus, *254. Phos, *221. Phosphoraz, 23, 295. Photinula, *265. Phragmoceras, *194. Phragmocone, 39, 173. Phyllidia, #324. Phyllidiade, *324. Phyllirhoe, *338. Phyllirhoide, *338. Phylloda, 480. Piyllodesmium, 335. Physa, 387, *301. Physema, *320. Physiology, 15. Physopsis, *302. Pileolus, #261. Pileopsis, *277. Pilidium, #281. Pinna, 30, 31, *419. Pinnoctopus. *165. Pirena, 36, *248. Pireneila, 243. Pisania, *214. Pisidium, *462. Pisum, 461. Pitonillus, 310. Placenta, *410. Placo-branchus, 339. Placuna, *409. Placunomia, 409. Placunopsis, *410. Plagioptychus, 450. Plagiostoma, 412. Planaxis, #223. Planorbis, *302. Planorbula, 303. Pranulites, 197. Platyceras, 277, Piatyodon, 489. Platyschisma, 267. Platystoma, *254. Platystrophia, 380. Plaxiphora, 284. Plectambonites, 381. Plectrophorus, 297. Pleiodon, 435. Plesioteuthis, *172. Pleure, 21. Pleurobrancheea, *323. Pleurobranchide, *322. Pleurobranchidium, 323. Pleurobranchus, *822. Pleurodon, 427. Pleuromya, 497. Pleurophorus, *468. Pleurophyllidia, 325. Pleuropus, 386, 349. Pieurorhynchus, 454. Pleurotoma, *228. Pleurotomaria, *270. licatula, 55. *414, Plocamophorus, 331. Pneumodermon, 347, *355 Pododesmus, 409. Podopsts, 414, Polia, 487. Polinices, *236. Pollia, 214. Potycera, *330. Polydonta, #304. Polygyra, 289. Polynesian recion, 104. Polyphemopsis, 241. Polyphemus, 292. Polytremaria, *270. Pomatias, *307. Pomato-branchia, 312. Pomus, 259. Pontolimax, 340. Porambonites, *376. Porcellanous shells, 32. Porcellarius, 232. Porcellia, *344. Poromya, 491. Poronin, 459. Portuguese shells, 64. Posidonia, 417. Posidonomya, *417. Posterobrancheea, *322. Potamides, *243. Potamomya, *490, Potamophila, 486, Poterioceras, 193. Priamus, 220. Prisodon, 434. Proctonotus, *337. Productide, *383, Productus, *384. Pronites, 380. J'ronoe, 470. _Pro-pilidium, 281. Proserpina, 286, *289. Prosobranchiata, *209. Proto, 249. Protocurdium, 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. Pteriza, *417. Pterochilus, 336. Pterocyclos, *308. Pterodonta, *315. Pterodoris, 329. Pteronites, 417. Pteroperna, *416. Pteropoda, 346. Pterotheca, *350. Pterotrachea, 342. Ptychina, 456. - Ptychoceras, *201. Cr 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. Pyramnus, 469. Pyraaus, *245, Fyreila, 217. Pyrgula, 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. Reniella, 416. Representative species, 54, 129. Reproduction of lost parts, 40. Requienia, 346, *439. Respiration, 596. Respiratory system, 25. Retractors, 20, 402, Retzia, *374. Reversed shells, 37. Rhabdoceras, *196. Rhegostoma, *309. Rhinoclavus, *242, Rhinodomus, 221. Rhizochilus, 222. Fhizorus, 317. Rhodope, *340. Rhodostoma, 304. Rhomboides, 502. Rhyncholites, 182. Rhynchomya, 495. INDEX. Rhynchonella, 308 ~*310- Rhynchonellide, *375. Rhynchora, 365. Rhynchoteuthis, 182. Ribeiria, *497. Ricinula, *223. Rimella, 211. Rimula, *274. Rimularia, 275. Ringicula, *222. Ringine'la, 314. Risella, *253. Rissoa, *255. Rissoella, 256. Rissoina, *256. Rivicola, 301. Rossia, #170. Rostellaria, 35, 55, *212. Rotella, *265. ‘ Rothomagenses, *193. Roxania, 316. Rudistés, 440. Runcina, *323. Fupellaria, 476. Fiupicola, 495. 5d5 ? 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. Sced, 352. Sceeureus, “165. Scalaria, *250. Scaldia, *498. Scalites, *270. Scapha, 230. Scaphander, *318. Scaphaniadia, 182. Scapharea, 424. Scaphella, *230. Scaphites, *20G. 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. Sedewickia, *497. Segmentina, 303. Semele, *483. Semicorbis, 457. Sepia, *177. Sepiadee, *176. Sepiola, *169. Sepioteuthis, *168. Septa, 184. Septaria, 506. Septifer, 421. Seraphs, *212. Serpularia, 266. Serripes, *454. Shell, 28, 204. Sigaretus, *236, Swliqua, 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, *2&9. Siphonotreta, #390. Siphonotus, 320. Siphopatellu, 276. Siphuncle, 39,174,180, 184. Skenea, *256. Smaragdinella, 316. Smell, 18. Solarium, *253. Solecardia, 460. Solecurtoides, 488. Solecurtus, *488. Solemya, *429. Solen, *486. Solenella, *429. Solenidee, *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. Sptratella, 351. Spirazis, 293, Spirialis, 347, *351. Spirifera, *371. Spiriferidee, *371. Spiriferina, *372. Spirigera, 373. Spiroglyphus, 249. Spirula, 9, *178. Spirulidee, *178. Spirulirostra, *177. Spisula, 477. Sponsiylobolus, 387. Spondylolites, 183. Spondylus, 7, 30, 35, 38, 55, *413. Spongaria, 180. - Spongiobrancheea, *354. Sporadic species, 51. Sportella, 457. Stalagmium, 427. Steganostoma, 308. Stenoceras, 197. Stenogyra, *293. Stenopus, *289. Stilifer, 9, *24%. Stoastoma, *310. Stomatella, *267. Stomatia, *268. Stomatia, 236. Straparollus, 267. Strephona, 227. Strepsidura, 218. Streptaxis, *289. Streptorhynchus, 380. Striati, *189. Strigula, 480. Strobilus, 294. Strombidee, *210. Strombus, 31, *210. Strophalosia, *885. Stropheodonta, 381. Strophomena, *3880. Strophostoma, 308. Structure of shell, Brachi- opoda, 360. Struthiolaria, *246, Stylina, 241. Styliola, 349. Stylocheilus, *821. 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. Sunetta, 474. Susaria, *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. Tegula, 264. Teinotis, *269. Tetlina, 458. Teilina, *480. Tellinide, #479. Tellinides, *480. Tellinodora, 480. Tellinomya, *497. Temnocheilus, 189. Temperature, 39. Tentaculites, *190. Tentaculites, 350. Terebellum, *212. Terebellum, 248. Terebra, 55, *220. Terebralia, *243. Terebratella, *365. Terebratula, 19, 38, 3857, 358, *363. Terebratulide, *363. Terebratulina, *364. Terebrirostra, 365. Teredina, *507. Teredo, 35, 341, *506. Tergipes, *335. Tertiary shelis, 130. Testacella, 9, *298. Tethys, *333. Tetrabranchiata, *178. Tetraplodon, 434. Teudopsis, *168. Teuthide, *167. Teuthis, 167. Texture of shells, 29. Thalassides, 470. Thallicera, 259. Theea, 190, 346, *349. Thecacera, *330. Theceurybia, 350. Thecidium, 358, *369. Thecosomata, *348. Thetis, *491. Thiara, 246. Thoracoceras, *191. Thoracoceras, *195. Thracia, *495. Thyatira, 456. Thysanoteuthis, *172. Tiara, 231. Tichogonia, *423. Tiedemannia, *351. Tomella, *229. Tomigerus, 289. Tongue, 287. Tonicia, 283. Torcula, 248. Torinia, *253. Tornatella, *313. Tornatellide, *312, 517 Tornatellina, *294, Tornatina, *315. Torquilla, 292. Toxoceras, *200. Trans-Atlantic prov., 85. Trapezium, 467. Trawling, 139. Tredopsis, *289, Trematis, *389. s Tremoctopus, 159, *164. Trevelyana, #331. Triboniophorus, *297. Trichites, 31, *420. Trichocyclus, *354. Trichotropis, 33, 55, *216. Tricolea, 263. Tridacna, 13, 35, 55, *452. Tridacnidee, *451. Tridonta, 464. Triforis, 37, *242. Trigona, *474, Trigonella, 375, 477, 484. Trigonellites, 182. Trigonia, *430. Trigoniade, *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, 52. Tudora, 307. Tugonia, 489. Tunicata, 5. Turbinella, *216. Turbinellus, 31. Turbinide, *263. Turbo, 23, *265. 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. 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. OUnionites, 468. United States shells, 85. Otricuius, 317. Vaganella, *479. Vagina, 487. Vaginella, *349. Vaginulus, *300. Valvata, *260. Vanicoro, 237. Varices, 135. INDEX. Varieties, 46. Varigera, *314. Varix, 35. Velates, #261. ~ Velletia, 286, *302. Velorita, *463. Velutina, 55, *237. Venericardia, *472. Veneridze, *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 repreduction, 40 Viviparus, 257. Vola, 412. Volupia, *473. Voluta, 32, 55, *239. Voluteila, 230. Volutide, *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, *478. Zaria, 248. Zellania, *368. Zephrina, 331. Zierlania, 231. Zirfed, 505. Zonites, 289. Zua, *252. INDEX TO FIGURES. Achatina, 286. Actinoceras, 191. ALCS, 327. Ammonite, 179, 181, 197, 199 Ampullaria, 258, 259. Ancula, 327. Anodon, 398. Anomia, 402. Aporrhais, 245. Argiope, 368, 359. _Argonauta, 161, 162. Ascidia, 6. Astarte, 465. Athyris, 373. Atrypa, 378. Aulosteges, 385. Auricula, 503, 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, 245. Chama, 437. Chilinia, 301. Chitonellus, 284, Chonetes, 386. Clymenia, 180, 199, Conocardium, 455. Conularia, 350. Conus, 32, 34. Crania, 387, 388. Crassatella, 466. Crenella, 43. Crepidula, 275. Cyclophorus, 306. Cyclostoma, 307. Cymba, 29, 251. Cypreea, 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, 208. Fasciolaria, 215. Fissurella, 273. Glycimeris, 494. Gomphoceras, 181. Goniatites, 181, 193, 196. Gryphea, 35, 408. Gyroceras, 194, Hamites, 180, 201. Helix, 4. Hippurites, 444, 445, 446. Huronia, 192. * Hyalea, 4, 348. Tanthina, 6,271. —~ Isocardia, 467. Kingena, 368. Kraussia, 367. Lepteena, 381. Lepton, 18, 460. Limax, 295. Lingula, 391. Littorina, 207, 250, 251. Loligo, 4. Lymneza, 301. Maclurea, 345. Magas, 366. Merista, 374. Modiola, 403. Monopleura, 438. Morrisia, 356. Mulleria, 436. Murex, 213. Mya, 6, 3965 489. Mytilus, 48. 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. Panopeea, 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. Prigonia, 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 Tennant, and Mr. Lovell Reeve. The fractions show the number of times (or diameters) the figures are reduced, or magnified. PAE a Octopodide. Page 1. Octopus tuberculatus, Bl. 3. Mediterranean .......... Seite Oe 2. COMLLESESNe BEADS Ab AGN oI Ojo Os IgOD 66055520 156 8. Tremoctopus violaceus, ¢.' Chiaje. Messina .......... 159, 164 Teuthide. 4S Sepiola Atlantica; Orb. Atlantiécs .j2is aaa 185 11. — —hidorsatus, Schl. (upper mandible = Rhynhcolites hirundo, F. Biguet). #2. 'Muschelkalk, Bavaria 183 12: —{Aturia) zic-zac, Sby. Eocene, Highgate ........ 189 16. Clymenia striata, Minst. Devonian, S. Petherwin ........ 190 15. 13. Orthoceratide. . Orthoceras Ludense, Sby. (section). +. Ludlow Rock, Britain 190 Phragmoceras ventricosum, Stein. =.‘ L. Ludlow-rock, Salop 194 Gyroceras eifeliense, Arch. (section). 4. Devonian, Hifel .. 194 o2 2 MANUAL OF THE MOLLUSCA. PLATE IIT. Aimmonitide. Page 1. Goniatites Henslowi, Sby. 4. Carb. limestone, Isle of Man 196 2. Ceratites nodosus, Brug. +. Muschelkalk, Wiirtemberg .. 197 3. Ammonites planulatus, Sby. 4. Chalk-marl, Sussex ...... 199 4, rothomagensis, Brongn. 4. Chalk-marl, Sussex 198 5. —————— spinosus, Sby. 3. Oxford Clay, Caan 4 198 6. ——— bifrons, Bruce. 4. “Lias, sW bitbyeess. eee 198 7. bisulcatus, Brug. +. Lias, Lyme-Regis........ 198 8. Crioceras cristatum, Orb. #2. Gault, S. France............ 199 9. Scaphites equalis, Sby. 2. Chalk-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 id Baculutes anceps, lam. 3.’ Chalk, Wiramce. 77)... ores 9 ere 201 14, Ptychoceras Emericianum, Orb. 2. Neocomian, 8. France 201 15. Hamites attenuatus, Sby. 4. Gault, Folkestone .......... 201 16. Turrilites costatus, Lam. 4. Chalk-marl, Sussex.......... 200. SP Woedwerd. SW. Lowry Je - PLA. ny Blane NAN eM f | LLP MVE PUEDE a _——— JP Woodward EXPLANATION OF THE PLATES. PLATE LY. Strombide. Page J, Strombus pugilis, Lb. 3}. W. Indies ...........e seve eee 210 pA ——- Bartonensis, Sby. Eocene, Hants .............. si: eeucrmome lamps, U5. Chinad?.... sects see ce one PAU APehosneiania cura. spy. +. Kurachee *)... 5. ca... cee 212 5. Seraphs terebellum, L. 2. Chima............ NER 212 6. Struthiolaria straminea, Gm. 4. New Zealand............ 246 7. Aporrhais pes-pelecani, L. %. Britain ...... ide ty See 245 Muricide. Sete bamstellum, Ey. Se Chinas. hes oc cates iw Qiagen alas 213 9. fenuispma, Lam.» +.) Moluctastin 1 ade. eumeiad. 20S 10. palma-rasceydaam: +. Ceylon. tac whe Con sonpelan 213 10.* erimaceus, L. (operculum). Brita 2... 0.0.6 cass e ees 213 11. Typhis pungens, Soland. ocene, Barton .....° = ioe: nee 214 12. Ranella granifera, Lam. 2. N. Australia ........ Aise Eads. 214 13. Triton tritonis, L. 1. New Guineas Pace weevsey: das 214 14, Pisania striata, Gm. sp. Mediterranean ..........0000 0008 214 15. (Enzina) turbinella. Kiener. Ne Revco hs haveeee esa 214 16. Trophon Magellanicus, Gm. 4. Tierra-del-fuego ........ 218 524 MANUAL OF THE MOLLUSCA. PLATE ey: Muricide. Page i: Basciolaria tulipa, ti.. /4. “W.. Undies®. |... sare) ete) 2. Lurpineila pyrum, 1. 2. sCeylongei.... > ay oes eee oe 216 3. ———— (Cynodonta) cornigera, Lam. 3. Moluccas ...... 216 4, — (Latirus) gilbula, Gm.sp. 4. Australia ...... BP AES 5. Cancellaria reticulata, Dillw. sp. W.Indies ............ els GocPyruladious, Gam... Chima ye... a. <6 pane oe eer oe eigen We (Myristica) melongena, L. 4. W. Indies ...... ceo, ae Saebsus-colus, ia; 2. sey lOM 2). epi ac. be eee 218 9. —— (Chrysodomus) antiquus, Mull. (var. contrarius, Sby-) oes (operculum). [Red Crag, Walton, Essex 218 Buccinide. 20. Buccinum undatum, i. e. Mibritam<., . 0. inert eee cee 219 i. Kburna, spirata; Ju. sp. 92. Ceylon.” ...5¢2 ee eee 221 12. Pseudoliva plumbea, Chemn. sp. . 2... Capes.cc.ee. ech ™ >. 220 3.” Lerebraamaculata, du.sp. i. . Moluccas)... eee emer 220 14, — (Builia) semiplicata, Gray. 8. Africa ........0..60. 220 15. Nassa arcularia, L.sp. 2%. Moluccas ...... Selah eke eee 221 16. —— (Cyclonassa) neritea, L. sp. Mediterranean .......... 221 7. ——. (Cyllene) Owen, Gray. “HK. Africa .2..020. Uae dates 221 18. Phos senticosus, L. sp. SV EN dAoistralia ‘iyi, Lee cee 221 19) Macilus-antiquus, Montf. 4. Red Seas... 00 See 224 20. == (do. young. — {LeEptaconchus) oe... sss sos oe eee ene 224 21. ? Ringicula ringens, Lam. 2. Tocene, Paris ..........,. 222 al haan) Ky WANG RRS SP Woodward. \\ oN \ atl SSX \ \ = ... eee 1 eee eee 247 24, Litiopa bombyx, Kiener. Mediterranean.................. 250 25. Truncatella subtruncata, Mont. sp. 2. Mediterranean .... 286 Paludinide. 9orPaludina ListermsHanley. 4, Norwich! nanos 4. 5 eee 257 27. (Bithynia) tentaculata, Mont. Norwich............ 258 25..Valvata piscmalis, Mull. - Norwich) .,...2... ens - = - ata 260 29 —— Cristaraeavulle, Norwich —.. d,s ete me iene 260 30:-Ampullariatelobosayew./ 4./2ndia 622... eee eee 258 31. ————— (Marisa) cornu-arietis, L. sp. Brazil .......... 259 32, —— (Lanistes) Bolteniana, Chemn. sp. 3, Nile .... 209 33. Amphibola australis. New Zealand ........ aye tte a ees 259 34, Paludomusaculeatus~Gmesp.: iCeylons 20. 2) Ae eee 247 Neritide. S5eeN ertta usp late: gas. G WOCUNGE 6 Sites + «+ ass adele ee eee ele eae 260 36. (Velates) perversus, Gm. sp. Eocene, Soissons ...... 261 37, 88. Pileolus plicatus, J. Sby. Bath Oolite, Ancliff........ 261 38; Nerina zebras Brug. . Paeie 2:2... . «ase a Beare ee 261 40. crepidularia, Less. India ..........-- esses cerees 261 41. Navicella porcellana, Chemn. sp. Mauritius—Pacific ...... 262 SE Woodward TWLowry 7. 3 me awa; r pea an vee HALO) EXPLANATION OF THE PLATES. 029 PLATE X. Page 1. Phorus corrugatus, Reeve. 4. Kurachee, India .......... 204 Turbinide. Seburmemmarmorazus, b. +. China... ..ciess scaces se nwas 263 3. Phasianella australis, Gm. sp. 3 “New Zealand .......... 963 4. Imperator imperialis, Chemn. sp. 4. New Zealand........ 264 ercocmus niloweus, Li. to “CMA Yee ae oo di ink «oS es ee 264 6. (Pyramis) obeliscus, Gm. sp. China ...... 265 7. —— (Margarita) helicinus, O. Fabr. Britain 265 8. ——— (Hlenchus) iris, Chemn. New Zealand ............ 265 S (Bankivia) varians, Gray. New Zealand ....... Fh eos 10; Rotella vestiaria, lu. sp. New Zealand .....c0e0ei. ce eee 265 i viGmodontatlabto, Wo sp. AV. Africa)... d kit tae tes 265 12. —————— (Clanculus) Pharaonis, L. sp. Red Sea ........ 265 13. Delphinula laciniata, Lam. China ........ btiin ard o, ceoleererste 266 14, — (Liotia) Gervillii, Defr. Eocene, Sussex ...... 266 15. ——_——_— (Cdllonia) marginata, Lam. 14. Eocene, Paris 266 16. —— (Cyclostrema) cancellata, Marryatt. Philippines... 266 17. Adeorbis sub-carinatus, Mont. sp, Britain ...........4...: 26€ 18. Euomphalus pentangulatus, Sby. 4. Carb. limestone, Ireland 267 19. Stomatella imbricata, Lam. India ee en ear PDAS 20. (Broderipia) rosea, Brod. 2. 8. Seas ........0, 267 . Halotide. 21. Haliotis tuberculata, L. Guernsey .:...... parks ate Dyctearay ee 268 22 Sromanaspayanots, Evel blin. “Java... 22. .cc sae ses va ee oe 268 23. Scissurella crispata, Fleming. #. Britain ................ 269 24. Pleurotomaria Anglica, Sby.- 4. Dias, Gloucester ........ 270 25. Murchisonia bilineata, D’Arch. Devonian, Hifel .......... 270 26. Trochotoma conuloides, Desl. Bath oolite, Stroud.......... 271 . Ianthina fragilis, Lam. 2. W. Indies — BIG MODE eRe SSO COORDS io 9 OSI TE OY Oe 05.0 oe 2 Wa) . Fissurella Listeri, Orb. “W. Indies ..... ‘ . Puncturella Noachina, L. sp. N. Britain . Rimula Blainvillii, Defr. Philippines . “I CV Be oo bo 0 MANUAL OF THE MOLLUSCA. PLATE XI. Fissurellid@. macrochisma, Humphr. Philippines. 6. Emarginula recticulata, Sby. Britain 8. 2° Calyptreide. 10. Calyptreea equestris, L. sp. Philippines ........ AM: — .Dillwynnii, Gray. W. Indies ...:.. 12. — (Crucibulum) radis, Brod. W. America, 73, 14. —— (Wrochita) radians, Lam. W. America io 1o*. ————— Sinensis, L. Britain........ 16. Crepidula fornicata, L. sp. W. Indies..... Ar (Hemitoma) rugosa, Quoy. Tasmania,. . Parmophorus australis, Bl. 4. New Zealand ee es ee re 08 i Pdleopsis Gungaricns, U2) Torbay. aoe oe eee ee a 18. ———. militaris, 1... W. Indies 2...0... 2 2S 19. ——— (Amathina) tricarinata, Gray. 2. India .......... 20. Hipponyx cornucopie, Defr. 4. Eocene, Paris .......... DN oe SCL hy Gdasie)icy ein Seven cio ceiee eee oe Patellide. 22. Patella longicosta, Lam. 2 Cape TE WN ey 2306 (-Naceia), pellucida, Au. iriaun oe Aa ee 24. Acmea testudinalis, Mull. sp. Britain........0.......ven. 25. Siphonaria sipho. Kurachee, India gies ath ts eon 26. Gadinia peruviana, Gray. Peru 27. . Chiten squamosus, L. 34. W. Indies - ——— (Acanthochites) fascicularis, L. Britain (Chitonellus) fasciatus, Quoy. 4. Philippines Dentaliade. Dentalium elephantinum, L. 3. Red Sea Chitonide. ee eee eee ee eecereece rene ——— (Acanthopleura) spinosus, Brug. N. Australia ...... sD bo ee) Co bb ho ao > SS Whowry 40 SL Woodward. : SP Weedwarid. JM Lowry fe. £O DOT SrA G9 PO Es EXPLANATION OF THE PLATES. PLATE XII. Helicide. ..Helix (Acawus) heemastoma, L. 2. Ceylon ..sccseceeeee — (Polygyra) polygyrata, Born. 3. Brazil ............ — (Carocolla) lapicida, L. Britain ..... ev oleleketeFotelene aisesers —— (Anastoma) globulosa, Lam. Brazil ..............5. —— *(Tridopsis) hirsuta, Sby. U. States ........0... 000. —— (Streptaxis) contusa, Fér. Brazil ............ Be diate ——— (Sagda) epistylium, Mull. Jamaica ............66.. eee (Aehicelia) cellaria, MULL, Britain ... «60 eie4 es aeiee seins —— (Stenopus) levipes, Mill. Malabar..... iarbaccmeneseos Os . Bulimus oblongus, Mull. $. Guiana...,.. Sear ALe a Rhee ens IT, 12. decollatus, L. S. Europe......... Pe eR ny CeReeR (Partula) faba, Martin. Tahiti ........0...s.ee0- (Zua) lubricus, Mull. Britaim 1... sees eee ns (Azeca) tridens, Pulteney. Britain .............. . Pupa uva, L. sp. Guadaloupe .........ceeeeee reve eeeees (Vertigo) Venetzii, Charp. 3. Pliocene, Essex ...... . Megaspira elatior, Spix sp. 3 Brazil ........ see eseevees . Clausilia plicatula, Drap. Kent. ... 0... cc cece cee e cece eens . Cylindrella cylindrus, Chem. sp. 3. Jamaica ........+4.. . Balsa perversa, L. sp. Britain ...... cc ceee eee e cece neve ne . Achatina variegata, Fab. Col. 3. W. Africa ..........5% SSmecmiea, puter tis. Britaits spci elt la a) 5 «je'% «athyebns! ojele opaser'e (Omalonya) unguis, Orb. Paraguay ......... ee Limacide. . samax maximus, L. Britain ......... Manis Ia aera ieee 2 . Testacella haliotoides, Fér. +. Britain ......cceceeenees . Parmacella (Cryptella) calyculata, Sby. Canaries .......... . Vitrina Draparnaldi. Cuy. Britain .. .......ssseseeeee (Daudebardia) brevipes, Drap. 2. AMSEC, Australian un oes. i ieienke itn 424 11 PeKata, Say. saeco) Oo Warpling ).haras | sotreee ae wee ADA 12. —— (Bysso-area) Now, L. 3. Medit.....c..e.ssee eens napa ee ——————— zebra, Sw. 3. Australia ....... Bee en 494 14. Cucullza concamerata, Martini. 4. India...........en00. 425 15. Macrodon Hirsonensis, D’Arch. sp. 4. Bath Oolite, Brit... 425 16.*Pectunculus pectiniformis, Lam. 3. India................ A425 17.*Limopsis aurita, Broc..sp., Crag, Suffolles....ccignatisn 2 aoe 426 18. Nucula Cobboldiz, Sby. 4. Crag, Norwich.............. 426 19.*Nuculina miliaris, Desh. #. Hocene, Pamrigey. $e teh a sake aga ADT . 20.*Leda caudata, Donoy. Brit....... este Mea rem eee probe teestie ok 21.*—( Yoldia) myalis, Couthouy .2. Crag, Norwich ........ 498 22,*Solenella Norrisii, G. Sby. 3. Valparaiso............ By ee) 23. ——-ornata, G. Sby. sp. 3. Miocene, Patagonia...... 429 Trigoniade. 24: Triconia costata, Park. +.* Oolite; Brit. “issn meaner , 480 25. Myophoria decussata, Mimst. sp. ‘Trias, Tyrol ............ 431 26. Verticordia cardiiformis, Wood. 3. Crag, Suffolk ........ 472 io it NA 1 Ih & y fi ng ig MMi AK wv ASS NS 3F Moedward TW Lowry fc. EXPLANATION OF THE PLATES. 5387 PLATE XVIII. * he figures marked are /eft valves. Unionide. a { Page 1 Umno hitorahs, Drap. +. Auvergne «.......:.... erefetiedteree 433 2. —— (Monocondylea) Paraguayanus, D’Orb. 4. S. America 434 seatana ambiena, Lam. +. RR: Amazon...i..2 woes sce es 434 4, Hyria syrmatophora, Gronovy. 3. 8S. Americaf .......... 434 a aodmmexcitca, Lam. ¢. Africa, RiNile....i.cc.. esses 435 6. Mycetopus soleniformis, D’'Orb. 2. 8. America, R. Parana 435 7. Adtheria semilunata, Lam. +. Senegal ......... bia «eens es ate - 435 Chamide. 8. Chama macrophylla, Chemn. 4. Antilles ..............0- 437 lef CGWOR re alate «cares Sacecitmant < 6 OGL 437 10. Diceras arietinum, Lam. 4. Coral Oolite, France ..... eae 439 11. — VOfE COVE 0 ta Woe ek Palate ee nteat ic ic Se 439 12. (Requienia) Lonsdalii, J. Sby. 4%. Neocomian, Spain _ —Brit. eoeeoee ee cee eee ee eeeoes ee eoeevneseeeoesee eeevvs0e 439 Hippuritide. 13. Caprotina striata, D’Orb. U. Greensand, France .......... 451 14, WEfEUGIVE™ 72. epee ss az, os stonnis Stuace Soocdbee 451 Tridacnide. 15. Tridacna squamosa, Chem. 3. Bombay............-.-.+. 452 16. Hippopus maculatus, Lam. 4. N. Australia........ eer 453 Cardiade (part). 17. Lithocardium aviculare, Lam. 4. Eocene, Paris.......... 454 Cyprinide (part). se, Cardilia semi-suleaia, slam. ~ Amboima. ./ $<... iu.es ss: ose 469 19.*Megalodon cucullatus, J. Sby. 4. Devonian, Hifel........ 469 { The animal of Hyria has two siphonal orifices. 538 MANUAL OF THE MOLLUSCA. Cardiade. Page - i Gardium costatum, L.: (45. Clmap ak. -. 5. cen sens pee 453 2, ——— lyratum,G.Sby. 3. Madagascar..............+. 453 3. hemicardium, Bali ten. Chimnans.e%. jaebeaanar tees 454 4,* (Adacna) edentulum, Pallas. 3. Caspian ........ 454 5. Conocardium Hibernicum, Sby. 3. Carb. limestone, Kildare 455 LIucinide. 6.*Lucina Pennsylvanica, L. 2. W.Indies...... in ae etter ee Te (Cryptodon) flexuosa, Mont. Brit................. .. 406 S$: ‘Corbis elecans, Desh. 932) "Chima... cauise sedis 056 sneer iets 457. 9. Diplodonta lupinus, Broce. sp. Miocene, Turin ,........... 458 10. Ungulina oblonga, Daud. 2. W. Africa oe ésiieatos 11 Kellia Gaperousi, Desh. Californias. <<...4- -chewtebigeeene 459 12 (Poronia) rubra, Mont. 4. Brit. ........... pee ee mii 459 13. Montacuta substriata, Mont. ca Brite. oo gee A satin sousrole peewee 460 14. Lepton squamosum, Mont. 4. Brit. .......... see eeeeee 460 15. Galeomma Turtoni, Sby. Brit....... TS TS Sry isi 3 461 16.*Cyamium antarcticum, Phil 2. Falkland Ids. .......... 458 Cyclacide. A7ewCvelas cornea, i. “RR. Whames.... <2 1s... = 5 s+ - =jengeet © wie bose 18. = (Pisidium) amnica, Mull. 3. R. Thames .......... 462 19. Cyrenoides Dupontii, Joan. 3. ........0000e ere jae chorea 463 20. Cyrena cyprinoides, Quoy. 3. Ceylon .........sseeeneee 462 Dil (Corbicula) consobrina, Caillaud. Alexandrian Canal 462 Cyprinide. 22 Cy prinadslandica, Vs. Ns Brite os suse awl a eter ere onto 462 23. Cardinia Listeri, Sby. sp. 3. lias, Cheltenham .......... 470 94, Opis lunulata, Miller sp. Inf. Oolite, Bridport ............ 479 20. PLATE XIX: The figures marked are /eft valves. Myoconcha crassa, Sby. 3. Inf. Oolite, Dundry .......... 471 EI ALS), S My lf il i m . 4 2 \\ Hii \" iii, \ Anil i ii li é mil “4 ST ‘PWeedward . Es WY. Lowry Ic. ry uh ale EXPLANATION OF THE PLATES. 5389 PLATE) XX, * (All the interiors are right valves.) Cyprinide. Page I. Astarte suleata, Da Costa. Brit. ....... suarivers eae eherain Warente 464 2, Ciree corrugata, Chem. 4. Red Sea ........secerecseeee 464 eee OG. . a. - DLIbs .. Seca ds cuss so avanrale ae Gua eaes 466 4, Cypricardia obesa, Reeve. 34. India ...... OR te oe 467 5. Cardita calyculata, L. §. Africa ...... boi ete se 471 6. (Venericardia) ajar, Adans. W. Africa ............ 472 Veneride. an marempranpiia, Ti.’ * W. Tndiegin Po. s cad He auth sa See 473 Come yencroa dione, Li: *-2.~ W. Indies’. 5 is oss. oe eieees 474 9. ———— (Meroe) picta, Schum. 2. Chima,..0....ci.see0s AT4 10. ———— (Trigona) tripla, L. 2. Wz. Africa .........cce0e 474 . ———— (Grateloupia) irregularis, Baster. 2. Miocene, Bor- ROMA ah clio) ch aloe eL oneness «, © Sregene “whee ot we Ne SAE OSS 474 eee eceminsexOleta, Une 5. Britvey cc. ..t « 4 cee tm erane gen pale 474 13., lucinopsis undata, Pennant sp. Brit. ....)..-.0. e800 venees 475 ia weapes| pullasira; Wood. 2. ‘Brit. 5.0 cs0cssceecece veer Pees 475 15. Venerupis exotica, Lam. N.Australia................e005 476 ica Perecola lihophava, Retz.-" Medit.™ i... sis cee eee we eels wan 406 17. ———— pholadiformis, Lam. 2. New York ..........+. 476 18. Glauecomya Chinensis; Gray. Chima. .) 0.00. noeseceelee es 477 19. Capsula rugosa, Lam. sp. 3. N. Australia....cesseesees fie SOL 040 Mactride. Page i Macivarstultorum, i. yee. Writ... see oe Pre tice AERC E 477 2. Gnathodon cuneatus, Gray. 34. New Orleans ..... todas eats 478 3. Jautraria oblonga, Gmel, 74.) Brit. oy... «sees arias espana 479 4. Crassatella ponderosa, Gmel. sp. 4. Australia........... . 466 Tellinide. o. Telling lingua-telisy i. S. Antilles). an.c om seem ee ee 480 6. earnaria, 1.\ Amtilles' (2s tone ssa sss «oie eer eee 480 We planissima, Anton. 3. India. (TZ. rosea, Sby.)...... 480 8) Gastrana fragilis, 1.2. “Galway. ..2..+2% ~. -ee eee eee 481 9. Psammebia Ferroénsis, Chemn. Brit. ....... ats 482 10. —— squamosa,; ame: -Bormediy os)... sae eee 482 118 Semele reticulata,,Chemmns + tAntilles*. 2 = a... ssaceeee eee 483 12 (Cumingia) lamellosa, G. Sby. Peru .............. 483 13. (Syndosmya) alba, Wood. Brit..........:.06e...2-: 4§ 142 Scrobiculania piperata, Gm. sp. .4.- “Brit..¢-5 eee eee eee 15. Mesodesma glabratum, Lam. Ceylon ......... ci poke pag 16. —————— (Donacilla) Chilensis, D’Orb. 4. Peru ........ 484 17(: — (Anapa) Smithii, Gray. Tasmania ..,., aes 485 — 18. Ervilia nitens, Mont. Antilles .......... MEI ss S » 485 0; Donax denticulatus i: ~eAmtilles: 2a. .4\.2 5. acre 496 10: *Iiyonsia Norvesica,:Chemn. sp. °3,> Brit. 50. e ieee 498 112 Pandora rostrata, liam. . 3." Guernsey. 22.2002 cease 499 12. Myodora brevis, Stutch. New South Wales .............. 499 13. Myochama anomioides, Stutch. New South Wales ........ 499 14, Chamostrea albida, Lam. sp. 3. New South Wales ...... 500 Gastrochenide. 15. Gastrochzena modiolina, Lam. Galway .........-..-s+-0: 501 da. sp. siphonal orifices, in U. Greensand, Haldon, Devonshire... Sete eicemes jo cies te ticles ota Vor ee 501 16. mumia, Spengl. 3, Ta, diy 5 See eee 501 17. Clavagella bacillaris, Desh. 4. Pliocene, Sicily ........ .- 602) 18. Aspergillum vaginiferum, Lam. §. Red Sea.............. 503 | Pholadide. d 19. Pholas Bakeri, Desh. 4. India ..... Bs aay Saogoo 24 le 20. (Pholadidea) papyracea, Solr. 2. Brit. ............ 505 21. (Uariesia) striata, a, "We dndies=..../5.. 51> ee seid 505 22. (Parapholas) bisuleata, Conrad .........-..-.---- 506 23) Xylophaca dorsalis, urt. ip eBrit. 1°.) cles > -ielecee ee ee eee 506 24, 25. Teredina personata, Lam. London Clay, Bosnor, .veeee 507 25a. ——————- siphonal orifice........ é Thiele s eee CRORE ee 26.*Teredo Norvegica, Spengl. Brit. ...... ey aS i 3 - 506 27, -—_—_—__—————_ siphonal end of the tube, broken to show ENE Fo5554 Ar jo MUAA SO NGO IOSD AOA Sods O.0075 552 506 28. palmulata; Tart. (styles). Brite. ~. - 2s eee 507 ———— oo VIRTUE AND CoO., PRINTERS, CITY ROAD, LONDON. *2>d9> 55 WO HE TE Lowri Je. SIP Moedivuard - ae APPENDIX MANUAL OF MOLLUSCA, OF S. P. WOODWARD, A.LS., CONTAINING SUCH RECENT AND FOSSIL SHELLS AS ARE NOT MENTIONED IN THE SECOND EDITION OF THAT WORK. By RALPH TATE, A.L.S., F.GS. LONDON: VIRTUE & CO, 26, IVY LANE. NEW YORK: VIRTUE & YORSTON. 1868. , grande 9 “ i if a ‘F ys ; ears) * k e (tieakch “ 4a ah AY CLASS I.—CHPHALOPODA. ORDER J.—DIBRANCHIATA. Famity II1.—TEvUTHIDé. PHYLLOTEUTHIS, Meek and Hayden. Type, P. subovatus. Cretaceous. Nebraska. Pen corneous, thin, subovate, slightly concave below, and conyex above. From behind the mid- dle it narrows towards the front, the outline of the lateral margins being conyex, while the posterior end is more or less obtusely angular. Apparently related to Beloteuthis. and Teudopsis. (See p. 168.) Famity [V.—BELEMNITIDA.* The Shell of Belemnites consists fundamentally of :— 1. A hollow cone, the phragmocone, Fig. 1, », with a thin shelly wall, termed the conotheca, c, and which is divided by transverse septa, concave above and convex below, into cham- bers or loculi; the septa are perforated nearthe ventral margin bya siphuncle. 2. A guard or rostrum, g, more or less extensively enveloping the apical part of the phragmocone. ‘‘ The phragmocone is not a chambered body made to fit into a conical hollow previously formed in the rostrum, as some have conjectured, but both rostrum and cone grew together; the former was formed on the exterior of a secretive surface, and the latter on the interior of another secretive sur- face.”? (Phillips.) The rostrum is composed of calca- Fig. 1. reous matter arranged in fibres per- pendicularly to the planes of the lamine of growth. Pro- * See p. 173. B2 3 Dorsal aspect. = Ventral aspect. MANUAL OF THE MOLLUSCA. fessor Owen describes the fibres, in specimens from Christian Malford, as of a trihedral prismatic form, and zoooth of an inch in diameter. These fibres are disposed concentrically around an axis, a, the so-called apical line, which extends from the extremity of the phragmocone to that of the rostrum. Indica- tions of a thin capsule or formative membrane appear in some — Belemnites investing the guard; in those of the Oxford clay it is represented by a granular incrustation; in some hassic species it appears in delicate plaits, like ridges or furrows; in some specimens of Belemnitella mucronata from the upper chalk of Antrim, it is in the form of a very thin nacreous layer. 3. A pro-ostracum, or anterior shell, which is a dorsal exten- sion of the conotheca beyond the end where the guard disappears. The surface of the conotheca is marked by lines of growth, and, according to Voltz, it may be described in four principal regions radiating from the apex: one dorsal, Fig. 2, a, with See ao | Zea ———S Fig. 2. Fig. 3. Fig. 4. loop lines of growth advancing forward; two lateral, 6, separated from the dorsal by a continuous straight or nearly straight line, and covered with very obliquely arched strize in a hyperbolic form, in part nearly parallel to the dorso-laterai boundary line, and in part reflexed, so as to form lines in retiring curves across the ventral portion nearly parallel to the edges of the septa. ae CEPHALOPODA. There were at least three kinds of pro-ostracum in the family Belemnitide. A. Inmany Belemnites the extension of the conotheca seems to run out in one simple broad plate, Fig. 3, as in B. hastatus from Solenhofen. B. In Belemnites Puzosianus, D’Orbigny, the pro-ostracum is very thin, and apparently horny or imperfectly calcified in the dorsal region, supported laterally by two long, narrow, parallel, calcareous plates, Fig. 4, as in B. Puzosianus from the Oxford clay. Professor Huxley considers this difference between the pro-ostraca of generic importance. C. The third kind of pro-ostracum is exhibited by Orthocera elongata, De la Beche, the type of the genus Xiphoteuthis, Huxley ; it is calcareous, and is composed of concentric lamelle, each of which consists of fibres disposed perpendicularly to the plane of the lamella; the phragmocone is very long and narrow, and the guard cylindroidal. “Professor Huxley suspects that a thoroughly well-preserved specimen of Belemnoteuthis will some day demonstrate the exist- ence of a fourth kind of pro-ostracum among the Belemnitide. The genera in the family are:—1, Belemnites ; 2, Belemnitella ; 3, Aiphoteuthis ; 4, Belemnoteuthis ; 5, Plesiotewthis ; 6, Celceno ; 7, Beloptera ; 8, Belemnosis; 9, Conoteuthis; and ? Helicerus. *‘The A anthoteuthes of Munster, so far as they are known only by hooks and impressions of soft parts, may have been either Belemnites, or Belemnoteuthis, or Plesioteuthes, or may have belonged to the genus Celeno.”” (Huxley.) The genus Belopeltts, Voltz, was founded on the pro-ostraca _ of Belemnites, species of which were unknown. The genus Actinocamax, Miller, was founded on the guard of Belemnites and Belemnitella, the upper parts of which had decayed, and thus presented no alveolar cavity. OrDER II.—TETRABRANCHIATA. Faminty J.—NAvUTILIDA (including Famity I].—ORTHOCERATID#). DIVISION a@.—AIR-CHAMBERS CONFINED TO ONE PART OF THE SHELL. ASCOCERAS, Barrande, 1846.* Etymology, askos, a leathern bottle, and ceras. * At p. 185 Mr. Woodward refers to M. Barrande’s second volume of the ‘‘ Cephalo- pods of Bohemia.” The Ascoras, Glossoceras, and Aphragmites are here described. a?) MANUAL OF THE MOLLUSCA. Type, A. Bohemicum, Barr., Fig. 5. Shell flask-shaped, smooth, transversely or longitudinally striated, or ornamented with annular folds, or plicated. The terminal cham- ber (r) occupying the space above the air- chambers (s), and extending down one side of nearly the whole length of the shell in the form of a wide and deep cavity, which is embraced by the decurrent edges of the in- complete septa (four or fiveim number). This cavity also communicates at its base with a small siphuncle which traverses the minute apical air-chambers. Aperture of shell simple. The wide ventral cavity of Ascoceras is of the same nature as the large lateral siphuncle of Cameroceras. Distribution, 16 species. Lower—Upper Diagram of Ascoceras Q- = : i ( after Barvande). ieee B ohemia, Norway, England, Ca nada. GLOSSOCERAS, Barrande, 1865. Etymology, glossa, a tongue, and ceras. Type, G. gracile, Barrande. Upper Silurian. Bohemia. Shell similar to that of Ascoceras, but the dorsal margin of the aperture is extended in the form of a ligulate projection, sub- triangularly rounded at the end, and recurved towards the inte- rior of the shell. This process gives rise to a distinct lobe on each side of the opening, which is analogous to that which exists in Hercocerus, Ophidioceras, and in certain species of Phragmoceras and Gom- phoceras. Distribution, 2 species. Middle and Upper Silurian. Anti- costi; Bohemia. APHRAGMITES, Barrande, 1865. Etymology, a, without phragmos, a partition; and the usual termination. ; Type, Ascoceras Buchi, Barrande. Shell, similar to that of Ascoceras, but the air-chambers are ileciduous. Distribution, 2 species. Upper Silurian. Bohemia. g CEPHALOPODA. DIvIsiIon b.—AIR-CHAMBERS OCCUPYING THE WHOLE CAVITY OF THE SHELL. PILOCERAS, Salter, 1859. Hiymology, pilos, a cap, and ceras, a horn. Type, P. nvaginatum, Salter, Fig. 6. Shell, broad, conical, sub-cylindrical, or com- ressed, and slightly curved. Siphuncle and septa combined as a series of conical concave septa, which fit into each other sheathwise. Distribution, 3 species. Lower Silurian. Scot- land. Canada. Fig. 6. Diagram oO1 Liweerus ORTHOCERAS.* (after Salter). Sub-genera :— 1. GonrIocERAS, Hall, 1847. Etymology, gonios, an angle. _ Type, G. anceps. Lower Silurian. United States. Shell, having the general form and structure of Orthoceras, flattened with extremely salient angles; septa sinuous; section of shell, an extended ellipse with projecting angles; siphuncle ventral. 2. ENDoOcERAS, Hall, see W. M., uu. p. 192. 3. TRETOCERAS, Salter, 1858 (Diploceras, Salter, 1856). Etymology, tretos, pierced. Type, Orthoceras bisiphonatum, Sowerby. Lower Silurian. Wales. Shell elongated ; septa pierced by a sub-central beaded siphuncle, and also by a deep lateral cavity continuous with the terminal chamber, and passing down side by side with the siphuncle—the cavity affecting at least seven of the upper- most septa, if not the whole. CYRTOCERAS. tT Sub-genera :-— 1. ONOCERAS, see W. M., ii. 193. ‘‘ The shells of this genus and Cyrtoceras pass gradually into each other, but Onoceras may be retained for those species which are much inflated in the ante- rior half or two-thirds of the shell length” (Billings); and ‘‘ which have a more or less strangulated aperture” (Barrande), * See p. 190. + See p. 194. 7 MANUAL OF THE MOLLUSCA. 2. CYRTOCERINA,* Billings, 1866. Type, ©. typica, Billings. Shell having the general characters of Cyrtoceras, but differs in the short, thick form, and in the large siphuncle on the dorsal side. Distribution, 2species. Silurian. Canada. 3. STREPTOCERAS, Billings, 1865. Etymology, streptos, curved, and ceras. Shell having the form of Onoceras, but with a trilobed aperture like Phragmoceras. Distribution, 2 species. Middle Silurian. Canada. Litvuires, Breynius.t Type, L. lituus, Hisinger. Shell discoidal, whorls (2—5) close or separate; last chamber produced in a straight, or nearly straight line, sometimes slightly curved, in a direction contrary to that of the spire ; lateral margins of the aperture extended and curved towards the interivr of the shell; the aperture contracted thus presents two distinct orifices, the smaller corresponding to the convex or ventral side, the larger to the concave or dorsal side of the shell. L. lituus is the only species in which the aperture has been observed. 28 species from the Middle and Upper ? Silurian rocks of Kurope and North America, belong here or to allied genera. Sub-genus :—OPHIDIOCERAS, Barrande, 1867. Synonym, Ophioceras, Barrande, 1865. Etymology, ophiodes, shaped like a serpent, and ceras. Type, O. Nakholmensis, Kjerulf (Litwites). Shell with the produced portion very short or wanting. The shells of the Bohemian species are keeled on the convex side. Distribution, 7 species. Middle Silurian; Norway (1). Upper Silurian, Bohemia (6). LitvuuncuLvs, Barrande, 1867. Shell as in Lituites, but with a simple aperture. No species have been yet observed. Sub-genus :—DiscocERas, Barrande, 1867. Litymology, diskos, a quoit, and ceras. Type, D. antiquissimus, Hichwald (Litwites). 5 * See p. 194. t See p. 189. CEPHALOPODA. Shell with the produced portion very short or wanting. This sub-genus bears the same relation to Litwunculus (the existence of which is supposed) that Ophidioceras does to Lituites. Distribution, 3 species. Middle Silurian. Russia, Germany, Norway. HERCOCERAS, Barrande, 1867. Etymology, erkos, a wall, and ceras. T'ype, H. mirum, Bar. Middle Silurian, Bohemia. Shell usually involute, as in Nautilus, rarely with separated whorls as in Gyroceras, or with a spire as in T'rochoceras. Body- chamber with a diaphragm perpendicular to the axis of the shell, the concavity of which is opposed to that of the last septum. This disposition throws the aperture on the convex side of the shell, which is deeply excavated. Siphuncle dorsal, cylindrical, inflated between the chambers, separated from the shell. Nautilus subtuberculatus, Sandberger, from the Devonian of Nassau, may belong to this genus. BATHMOCERAS, Barrande, 1867. Hiymology, in allusion to the imbricated arrangement of the partitions. Type, B. complexum, Barr. (Orthoceras). Sheli having the general appearance of Orthoceras. Part of the body-chamber occupied by a series of imbricating plates, which decrease in horizontal extension from below upwards. Siphuncle composed of a series of superimposed funnel-shaped tubes, the narrow end directed towards the aperture of the shell. Distribution, 2 species. Middle Silurian, Bohemia. AULACOCERAS, Hauer, 1860. Hiymology, aulax, a furrow, and ceras. Type, A. sulcatum, Hauer, Fig. 7. Shell straight, like Orthoceras ; corrugated, with two deep lateral furrows; siphon simple, very small, marginal and dorsal, situated between the longitudinal sulci. The test increases rapidly in thickness towards the — apex of the shell. The genus is a transition form between Fig. 7. Transverse sec- the Nautilide and the Belemnitide. timotl -Adiacocer tes aid: Distribution, 4 species. Upper Trias, catum. Austria. B3 9 ‘MANUAL OF THE MOLLUSCA. aot [FamiIty GonraTip#. Barrande. | Shell involute or straight; septa concave in their median section ; sutures usually with angular lobes; septai tubes coni- cal, more or less prolonged, but always directed backwards. Siphuncle cylindrical, of small diameter, always marginal ; siphonal investment not persistent; convexo-ventral margin of the aperture sloped, lines of growth and ornamentation of the shell with a corresponding sinuosity. The genera enumerated in this family are Goniatites, Clymenia, and Bactrites. Dr. Woodward includes the Goniatites and the Bactrites (pp. 196, 197) with the Ammonitide ; and the Cly- menia with the Nautilidee (p. 190). Famity IJ1.—AMMONITIDA. Shell various ; septa convex in their median section ; sutures always lobed, ramified, or denticulated ; septal tube cylindrical and always directed forwards. Siphuncle cylindroid of small diameter, always marginal; siphonal investment more or less solid and persistent. Convexo-ventral ? margin of the aperture more or less prolonged, which determines a similar convexity in the lines of growth and ornamentation of the test; there are rare specific exceptions. 5 DIvIsion I.—SUTURES LOBED OR DENTICULATED AT THE BASE. 1. RHABDOCERAS (see p. 196). 2. Bacutina, D’Orbigny, 1850. Example, B. Rouyana, D’Orb. Neocomian, France. Shell like Baculites, but its lobes and saddles are not foliated, there being between these forms a similar distinction to that between Ceratites and Ammonites. B. acuarius, Schlotheim, is from the Oxfordian strata of Gammelshausen in Wurtemberg. 3. COCHLOCERAS, Hauer, 1860. Etymology, cochlos, a snail-shell, and ceras. Type, C. Fischeri, Hauer, Fig. 8. Shell resembling that ae Turrilites, with the sutural lobes simple, as in RLhabdoceras and Clydonites, 10 CEPHALOPODA. Distribution, 3 species. Upper Triassic strata of Hallstadt, Austria. Fig. 8. Shell and sutural lobes of Cochloceras Fischeri. 4, CHORISTOCERAS, Hauer, 1865. Type, C. Marshii, Hauer. Shell somewhat similar in form to Crioceras, with the lobular ornamentation characteristic of Ceratites. Distribution, 4 species. Upper Trias, Austria. 5. CLYDONITES, Hauer, 1860. | ! I rl a AN | a ee Sk BOG ds al Fig. 9. Shell of Clydonites costatus, Hau. Figs. 10a, 10b. Shell and suturallobes of C. delphinocephalus, Hau. Etymology, kludon, the surge, with the usual termination. Examples, Goniatites Eryx, Minst; Ammonites delphino- cephalus, Hauer. Figs. 9, 10. Shell, discoidal; sutures lobed; lobes entire, not crenulated as in Ceratites. Distribution, Upper Triassic strata, Hallstadt and St, Cassian, in the Austrian Alps ; North-western Himalayas; 21 species. Upper Cretaceous, 2 species described as Ceratites by D’Orbigny. 11 MANUAL OF THE MOLLUSCA. 6. CERATITES (see p. 197). Division I1.—SUTURES FOLIATED Including the genera Ammonites (p. 197), Toxoceras, Ancylo- ceras,* Scaphites, Helicoceras, and Twurrilites (p. 200), Hamites, Piychoceras, and Baculites (p. 201), and the following. ANISOCERAS (see p. 200), Pictet, 1854. iitymology, anisos, unequal; and ceras. Hxample, Hamites armatus, Sowerby. Shell at first growing in an open helicoid spire, afterwards more or less prolonged and reflected; ornamented by trans- verse ribs. Sutures of septa divided into 5 lobes and 5d saddles, all bipartite ; the lateral saddles are the largest. Fossil, 12 species. Gault—Upper Green Sand, Europe. Cre- taceous, India. 1 species, Jurassic. North-west Himalayas. Species of Helioceras founded on helicoid portions of shells may belong to this genus. HAMULINA (see p. 201), D’Orbigny, 1852. Example, H. dissimilis, D’Orb. Shell conical prolonged, having a portion of the body chamber reflected, but not touching the other portion; section of the shell round or laterally compressed; sutures of the septa divided into six lobes, and as many saddles. | Hamulina differs from Hamites in bemg only once reflected instead of twice, and from Ptychoceras in haying the reflected portion of the shell separate from the other, not close together. Distribution, 15 species. Neocomian, France. Ootatoor group (= ? Gault), India. PELTARION, Deslongchamps, 1859. Founded on the mandibular armature of tetrabranchiate cephalopods * Many of the forms considered to belong to Crioceras have been ascertained by M. Astier to be only more or less incomplete individuals of species belonging to Ancyloceras. That Crioceras must merge into Ancyloceras appears inevitable. GASTEROPODA. Ewample, P. bilobatum. Upper Lias, Normandy. Fig. 11. Calcareous plates nearly circular or transversely oval ; ante- Fig. 11. rior border rounded, posterior produced and truncated ; concave above and flattened below; the two faces have one-half smooth and the other concentrically striated in an inverse direction to each other. fossil, 3 or 4 species. Up. Lias— Oor. Rag. England ; Normandy ; Wurtemberg. CLASS II.—GASTEROPODA. ORDER I.—PROSOBRANCHIATA. Famity I1.—MouRIcip& (see p. 212, &c.). The genera included in this family are :— Murex, TYPHIS, PISANIA, TROPHON, FASCIOLARIA, TURBI- NELLA (Cynodonta, Latirus, Lagena), Eusus (Clavella, Chryso- domus, Pusionella, Tritonidea), FULGUR, COMINELLA, MyRIs- TICA, and LACHESIS AwnaAcuHis, H. and A. Adams. Type, Columbella scalarina, Sowerby. Shell like Columbella; operculum elongated, unguiform, nucleus terminal, having close analogies with Pisania. Distribution, 27 species. Tropical America. PTYCHATRACTUS, Stimpson, 1865. Etymology, ptych, a fold; atractus, a spindle. Type, Fasciolaria ligata, Mighels and Adams. Deep water; United States. 13 MANUAL OF THE MOLLUSCA. Shell fusiform, spirally striated ; aperture with a rather long canal; columella plicated as in Fasciolaria; operculum like that of Chrysodomus. Lingual dentition, resembles that of the Purpuride, 1:1:1. | Rhachidian tooth, deeply arched, with three denticles; lateral teeth versatile, elongated, simple, hook- shaped, base swollen. Buccrnopsis, Jeffreys, 1859. Etymology, having the aspect of Buccinum. Synonym, Liomesus, Stimpson, 1865. Type, Buccinum Dalei, J. Sowerby, Britain. Shell oval, spirally striated; epidermis filmy; spire short, obtuse; outer lip smooth within; canal short and open; oper- culum triangular; nucleus placed on the inner base of the aperture. The lingual dentition makes an approach to Maes and consists of a single plain and slightly curved tooth on each side of a thin non-denticulated plate. The egg cases of Buccinopsis are separate. Distribution, 3 species. German Ocean, North Atlantic, Spitz- bergen, Behring’s Straits. Fossil. B. Dalei occurs in the Red, Antwerp, and Coralline Crags. England, Belgium. Cheletropis is the fry of species belonging to the Muricide. Adamsia, Dunker, resembles a sculptured Cominella without the sutural construction of the whorls. 2 species. Australia. Famity II1.—Bvuccmnipz.* The enumerated genera are :— BuccINuM, PSEUDOLIVA, BuLLIA, EspurNA, PHos, NAsSsA (Oyllene, Northia, Cyclonassa), COLUMBELLA, TRUNCARIA, and TEREBRA (Myurella), SUBULA (Huryta). TruncARIA, A. Adams and Reeve, 1848. Synonym, Buccinopsis, Deshayes. Type, T. filosa (Buccinum). Adams and Reeve. China. Shell oval, oblong; spire elongated; apex acute, often chan- nelled at the suture; aperture oblong, dilated in front, angu- lated, sometimes with a small canal behind; outer lip simple or bordered; columella concave, abruptly truncated, and shorter than the right lip. * See p. 218, &e. 14 GASTEROPODA. Species of this genus are Buccinums with a truncated colu< mella. Distribution, 5 species. China, Central Ameria, Vigo Bay. Fossil, 3 species. Hocene. Paris basin. [FAMILY PURPURIDZA] Is composed of the following genera :— PuRPURA, including Monoceros (of sectional value)* and the sub-genera :— Concholepas, Cuma, Rapana (see p. 217, under Pyrula), Pinaxia, Adams. lopas, H. and A. Adams, 1853. Shell bucciniform, with a small canal in the posterior angle of the aperture. Fossil, 3 species. Eocene. Paris. Vitularia, Swainson, 1840. YV. salebrosa. South and Central America. Shell with irregular varices; operculum as in Purpura. Nitidella, Swainson. Shell as Cylindra; spire sometimes decollated; lip continuous or crenated; operculum elongate; nucleus lateral. RIcINULA, HARPA, RHIZOCHCHILUS (Coralliophila, Adams), and MAGILUS, with the Sub-genus Leptoconchus, Riippell. Shell similar to that of Magilus; young shell only with an operculum. [FAMILY CASSIDZ. ] The genera referred to this family are :— RANELLA (p. 214), TRITON (p. 214), PyRULA (p. 217), Cassis (p. 224), ONISCIA (p. 225), CASSIDARIA (p. 225), Dorium (Malea) (p. 226), and NassaRiA, Pfeiffer. Animal analogous with that of Ranella, as regards the length of the tentacles, position of the eyes, smallness of the head, and by the form of the operculum, but is provided with a long branchial siphon. Shell sub-canaculated in front, and deeply notched. [FamiIty OLIvipz] Includes Oxiva (Olivella, Scaphula, Agaronia), ANCILLARIA (Monoptygma, Lea). * See p. 223, } See p. 227. 15 MANUAL OF THE MOLLUSCA. [FAMILY VOLUTIDZ] Contains COLUMBELLINA (p. 227), Mirra (Imbricaria, Cylindra, Strigatella, and Hyalina) (p. 231), VoLuTA (Volutilithes, Scaphella, Volutomitra, and Melo) (p. 230), CymBA (p. 231), MARGINELLA ~ (p. 232), VOLVARIA (p. 232), and | Lyris, Gray, 1847. Synonyms, Harpella, Gray; Eneeta, Gray. Types, Li. deliciosa, Montf.; L. harpa, Barnes. Shell ovate oblong, mitriform, thick, sometimes longitudi- nally costated ; aperture subovate, with a large number of columellar plaits, the two anterior of these being the strongest ; posterior portion of the inner lip provided with a large number of short cross-plaits. Operculum ovate-clongate, thin ; corneous nucleus at first nearly central, at a more advanced age sub- apical. Distribution, 14 species. Pacific Ocean, America, Madagascar, Australia, Japan, New Caledonia, Antilles. Fossil, 8 species. Cretaceous. India. The species in the Tertiary strata have not been distinguished from Voluta. Cystiscus, Stimpson, 1865. Type, O. capensis, Cape of Good Hope. Shell resembling that of Marginella; small, thin, ovate, inflated, smooth, and polished; aperture narrow, columella plaited. Animal with an elongated foot, truncated in front; head ob- long, depressed ; tentacles triangular, flattened, and horizontal ; eyes at the lateral margins of the head, at the bases of the ten- tacles. Lingual dentition, 0°1:0, resembling the rhachidian teeth of Murex, thick and strong, with seven unequal conical denticles. [FAMILY OCYPREIDZE] Includes Erato, Cyprma (Cyprovula, Luponia, and Trivia), OvuLa (Volva and Radius), PACHYBATHRON, PEDICULARIA, and DENTIORA, Pease, 1862. Type, D. rubida, Sandwich Islands. Shell differs from that of Pedicularia in the flat or excavated columella, compressed, and toothed. 16 GASTEROPODA. Faminy Conipz# Contains Conus (Conarbis), DisAPHUS, PLEUROTOMA (Drillia, Bela, Clionella, Daphnelia), CLAVATULA (Tomellia), MANGELIA (Clathurella), LACHESIS, CITHARA, and BorsontA, Bellardi, 1839. Synonym, Cordieria, Ronault, 1848. Shell like Pleurotoma, with oblique folds on the thick colu- mella, and thus establishes a passage between Plewrotoma and Turbinella. Distribution, 4 species. Hast Indies. Fossil, 23 species. Eocene—. France, Italy, England, United States. GOSAYVIA, Stoliczka, 1868. Type, Voluta squamosa, Zekeli. Shell similar to that of Conus; aperture narrow, elongated ; base emarginate ; outer lips notched near the posterior suture ; columella lip plicated, the anterior plaits being always the strongest. Fossil, 8 species. Cretaceous. — Hocene? Gosau; India. [Faminty NATIcIDsé. | The genera are— NATICA, containing as sub-genera WNaticospis, Neverita, Lunatia, Globulus, Globularia, Polinices, Cernina, and Euspira (Agassiz), Morris and Lycett, 1850. Spire more or less elevated ; whorls few, distinct, angulated, or carinated. Fossil, 6 species. Inferior Oolite—. Forest Marble. Eng- land, ‘‘ Huspira presents considerable affinities to the Paleeozoic genus, Scalites (Hall), in the lines of growth having the appear- ance of a slight fissure, where the angle occurs in the volution.” (Mor. and Lyc.) SIGARETUS (and sub-genus Naticina). LAMELLABIA (Oncidiopsis and Marsenia), VELUTINA. AMAURA. Type; A. candida, Moller. Greenland. 17 MANUAL OF THE MOLLUSCA. “Animal allied to Natica; foot small, compact without any posterior lobe ; the front lobe deeply sinuated; eyes subcuta- neous, situated at the internal base of the lobe; operculum terminal, few-whorled, horny, thin. “Shell ovate, imperforate, spire small, produced; mouth reversed, pear-shaped, about half the length of the shell.” | (Moller. ) Fossil, species. Cretaceous. Germany, Britain. DESHAYESIA, Raulin, 1844 (see p. 236). Dedicated to M. Deshayes, author of ‘‘ Description des Ani- maux sans Vertébres dans le bassin de Paris,”’ &c. Synonym, Naticella, Grateloup (non Minster). Type, D. Parisiensis, Raulin. Shell subglobose, thick, umbilicated; spire short; aperture entire, semicircular, oblique ; columella oblique ; callosity den- ticulated; umbilicus covered by the callosity; right lip acute, smooth internally. This genus presents a very remarkable combination of the characters of Natica and Nerita, and appears to establish a pas- sage between these two genera, types of distinct families. Distribution, 2 species. Oligocene and Miocene. Paris and Bordeaux Basins PTycHOsToMA, Laube. Fossil, 3 species. St. Cassian. [FAMILY CANCELLARIDZ. | The genera are— CANCELLARIA (Admete, p. 216), TRIcHOTROPIS (p. 216), ? CERITHIOPSIS (p. 242), P SEPARATISTA, and PurPurina,* D’Orbigny, 1850 (p. 222). Type, Purpurina Bellona, D’Orbigny, Fig. 12. * This genus has been the subject of careful research and revision by Messrs, Eugene Deslongchamps and Piette ; and I think it advisable to replace the characters. of this group, given in p. 222 of the Manual, by those emended by the authors above wentioned, 18 GASTEROPODA. Shell oval, elongated, -ventricose, thick ; whorls rounded or rendered angular by the upper portion being channelled ; last whorl much developed. Ornamentation usually of : large longitudinal ribs, crossed by numerous #¥ striz ; aperture large in the young state, fa shghtly notched in front ; columella rounded ; umbilical groove deep, narrow, but well de- fined. Fossil, 8 species. Inferior Oolite—Kelloway Rock. England, France, Germany. Fig, 12 Pdrpurina Bellona. TORELLIA (Loven), Jeffreys, 1867. Dedicated to Dr. Otto Torell, of Norway. Type, T. vestita, Jeffreys. Shetland and Norway. Animal with the produced lips and lingual dentition of Capulus. Shell globose, covered with a velvety epidermis; spire very short ; apex depressed ; aperture roundish ; pillar with a blunt tubercle at its base; groove internal, scarcely perceptible ; operculum like that of T'richotropis. [FAMILY NERITOPSIDZ. ] Genera :—NERITOPSIS and NARICA with Naticella as a sub- genus (see p. 261). [FAMILY PYRAMIDELLIDZ.*] The following genera and sub-genera are additional :— PYRAMIDELLA. Sub-genus Chrysallida, P. Carpenter, 1857. Shell pupiform; peristone continuous; edge of lip thin; columella-plait distinct, though hidden; operculum in the typical species radiately corrugated. Distribution, 25 species. EH. and W. Indies, Japan, Mazatlan. OpostomIA. Some of the Mazatlan species have the peri- stone continuous. Sub-genera :—Auriculina, Gray. Shell haying the general aspect of Odostomia, but presenting no vestige of a plait. Mazatlan, 3 species. Fossil, 4 species. Tertiary. United States. Parthenia, Lowe (Hbalia, Adams). Surface sculptured ; columella plaited. Distribution, 10 species. Mazatlan, Japan. * See p. 238. 19 MANUAL OF THE MOLLUSCA. ScALENOSTOMA, Deshayes, 1863. Type, 8. carinatum, Isle of Bourbon. Shell in form allied to Pyramidella and Niso, turriculated, white, imperforate; columella not plicated; opening subtri- angular, slightly bent in the direction of its length; margin simple, notched near the suture. CHEMNITZIA. Sub-genera :—Dunkeria, P. Carpenter (dedi- cated to Professor W. Dunker). Aperture as in Chemnitzia, but the whorls rounded as in Aclis; whorls cancellated. Distribution, 7 species. Mazatlan, Japan. Pseudomelania, Pictet and Campiche, 1864. Hiymology, pseudo, false, and Melania, a generic name. Shell turriculated, spire acute, test thick, imperforate, without ornamentation. Aperture oval, rounded in front, more or less angulated behind; columella thick, conforming to the general curvature of the aperture; lip simple. Distribution. Trias—Chalk. Europe, South Africa. The cretaceous species are 14 in number. . Hutima. Sub-genus :—Leiostraca, H. and A. Adams (Balcis, Leach). Shell with a slight varix on each side of the spire. Distribution, 8 species. Mazatlan, Taboga. ActouLiIna, Deshayes, 1864. Shell small, aciculated; apex laterally inclined; whorls numerous, convex, smooth; aperture entire, small, subqua- drangular; columella straight, narrow, cylindrical, and simple. Distvyibution, 6 species. Eocene. Paris basin. MATHILDA, Semper, 1865. Shell turriculated, apex revolute, abruptly turned from left to right; whorls in the typical species transversely cingulated and reticulated, longitudinally striated; aperture entire, subro- tund, base sometimes subeffuse; lip acute; columella smooth, not plicated. Distribution. The type Turritella quadricarinatus, Brocchi, is living in the Mediterranean, and is fossil in the Crag of Anvers, and at Bologna. Fossil, 13 species. Hocene—. Europe, United States. SoLEniscus, Meek and Worthen, 1860. Htymology, soleniskos, a little channel or gutter. 20 GASTEROPODA. Type, 8. typicus. Upper Coal Measures. Springfield, Illinois. | Shell fusiform, smooth, body whorls contracted below into a | distinct straight canal, with an oblique plait on the columella. Agrees with Macrocheilus in its smooth surface and columella fold, but differs in its fusiform outline, narrow aperture, and distinct canal. In its general appearance resembles Fasciolaria, but has only one instead of two or three columella folds, and is destitute of ornamentation, and its outer lip is smooth within. KUCHRYSALIS, Lambe. Fossil, 6 species. St. Cassian, Austria. [FAMILY STILIFERIDZ. | The genera are :— STILIFER.—Dr. Fischer supposes that Stilifer, though living like a parasite on the tegumentary system of the echinoderms or their appendages, does not feed on their substance, as has been supposed. Mr. Gwyn Jeffreys’s impression is that it feeds on the excretions of the echinoderms. STYLIFERINA, Adams. Shell imperforated, ovate conical, thin, smooth; whorls many, produced in a styliform spire; nucleus sinistral; aperture sub- quadrate; lp simple, straight. Distribution, 2 species. Japan. M. Freyer, of Trieste, is of opinion that Entoconcha (L. murabilis), which is parasitic on Synapta digitata, is the embryonic condition of a species of Natica. Famity IL1.—CERITHIADZ.* Includes CERiITHIumM (LRhinoclavis and Bittiwm), TRIFORIS, PoramipEs (Vicarya, Cerithidea, Terebralia, Pyrazus, and Lampania), NERIN@HA, and the following additional genera and sub-genera :— CERITHIUM.—Sub-genus. Sandbergeria, Bosquet, 1860. Dedicated to Professor Sandberger. Z'ype, Cerithium cancel- lata, Nyst. sp. Shell short, like Cerithium, canal terminal, very broad, and short. M. Bosquet describes the type as haying an operculum as in Stenothyra; it is very questionable as to whether the operculum belonged to the shell. *® See p. 242, &c. 21 — MANUAL OF THE MOLLUSCA. Distribution, 29 species. Cretaceous; India. Eocene. France, Netherlands. Evstoma, Piette, 1855. Type, HE. tuberculosa, Piette. Shell in the young state resembling Cerithiwm ; in the adult, the margins of the aperture are much expanded and posteriorly united by an indistinct canal; canal elongated. Fossil, 2 species. Great Oolite. Ardennes. EXELISSA, Piette, 1861. Litymology, exelisso, to unfold. Synonym, Kilvertia, Lycett, 1863. Type, Cerithium strangulatum, D’Archiac. Shell small, elongated, subcylindrical, somewhat pupeeform, many whorled, perpendicularly costated, tuberculated or spined ; last whorl cylindrical, contracted at the base, with a tendency to separate from the axis; aperture orbicular, entire, the lips elevated, produced, and slightly thickened ; columella solid. Fossil, 14 species. Mid. Lias—Kimmeridge Clay. England and France. The shelly freestone of the Inferior Oolite, Glou- cestershire, contains some undescribed species. Cretaceous, 1 sp. ? India. FIBULA, Piette, 1857. Example, Turritella Roissyi, D’Archiac. Shell elongated, columella straight, with a rudimentary groove near the base; outer lip arched, slightly notched at the suture; base of the aperture forming a slight canal, or rounded and entire, depending upon the exact period of growth at which — the animal perished. 4 The species of this genus possess characters intermediate and approximating them to Turritella and to Cerithium. Fossil, 21 species. Triassic—Oretaceous. Europe, India. « CRYPTOPLOCUS, Pictet and Campiche, 1854. Litymology, cryptos, hidden ; ploce, a plait. Example, Nerinzea monilifera, D’Orb. Shell, as in Nerincea, without columella and labial plaits ; one plait on the posterior face of the aperture, a disposition very analogous to that in some Cerithiwms, such as C. nodulosum { aperture rounds‘, not channeled in front; umbilicated or im- perforate. 22 GASTEROPODA. Distribution, 7 species. Jurassic and Cretaceous. France, Switzerland, Germany. PLANAXIS. M. Deshayes places this genus in Littorinide, but Dr. Macdonald states that it is anatomically closely related to Cerithium, the lingual teeth are similar, and that the audi- tory sacs contain spherical otoliths. QuoyiA, Deshayes, 1830. Dedicated to the celebrated naturalist to the Astrolabe. Synonyms, Fissilabria, Brown ; Leucostoma, Swainson. Shell solid, elongated, conical, apex decollated; whorls flat, the body whorl sub-angular at the base; aperture small, semi- lunar, produced in front; columella thick, curved, truncated anteriorly, with a spiral fold posteriorly, operculum horny, paucispiral, nucleus lateral. Distribution, 2 species. New Guinea, Cochin China. Fossil. Hocene, Paris (1). Miocene, Dax (1). The three following genera are provisionally referred to Cer- thiade. CERITELLA, Morris and Lycett, 1850. Ltymology, diminutive of Cerithium. Synonym, Tubifer (pars), Piette, 1856. Type, Ceritella acuta, Mor. and Lyc. Shell turreted, subulate, spire acute; whorls flat, margins usually sulcated; last whorl large; aperture elongated and narrow; canal short; columella smooth, rounded, and slightly reflected at the base; outer lip thin. Fossil, 17 species. Middle Jurassic strata. Hingland, France. BRACHYTREMA, Morris and Lycett, 1850. Etymology, brachyos, short, and tremos, a cut. Examples, B. Buvignieri, Mor. and Lyc., R. Wrightii, Cotteau (Fig. 13). Shell s small, turreted, turbinated; whorls either costated, owimilesi. or cancellated; the last whorl large and REE aOR: columella erin rounded, ¢ ‘ twisted near its base, and reflecting outwards, Ee forming a short, oblique canal; aperture moderately subovate, its length being usually less than that of the spire. Some species, as B. varicosa and B. pygymea, Fig. 1 acquired at certain arrests of growth thickened Brazhytroma outer lips or varices, as in T’riton. ce 23 MANUAL OF THE MOLLUSCA. Fossil, 16 species. The greater number belong to the Great Oolite, others occur in the Kelloway Rock. England, France. MesostomA, Deshayes, 1864. Example, M. grata, Dh. Shell elongated, turreted, scalariform; aperture nearly cir- cular, dilated, obliquely cut, terminating in front by a semi< canaliculated angle; columella slightly concave, cylindrical, obliquely truncated, lip simple, and slightly expanded. Fossil, 4 species. Hocene. Paris basin. [Famity APORRHAIDA, Gray, 1856, | Includes the genera APORRHAIS (see p. 244), PTERODONTA, STRUTHIOLARIA (p. 246), and HALIA; also ALARIA, Morris and Lycett, 1854. Synonym, Tessarolax, Gabb, 1864. Etymology, ala, a wing. Examples, Alaria trifida, Phillips, sp.; A. cingulata, Pictet and Roux, sp. Shell turreted, fusiform, terminating anteriorly by a canal; wing digitated or palmated, formed by the prolongation of the free border of the last whorl, and which is applied against the last whorl but one, but never adheres to the rest of the spire; posterior canal wanting; right ip without a sinus. Distribution, about 50 species. Jurassic. Hurope, Himalaya Mountains, South Africa. Cretaceous, 9 species. England, France, Germany. The species of this genus have been referred to Rostellaria, Pierocera, and Aporrhais. DIARTHEMA, Piette. Shell with continuous varices. Distribution. Lower Oolites. France. Pelicaria vernis, Adams, has a spiral shell; the spire of adult covered with an enamel coat ; aperture ovate; outer lip sinuous, sharp-edged. ? BULIMELLA, Hall, 1857. Shell more or less fusiform; whorls convex, the last one much enlarged; columella truncated; outer lip thin, with a slight notch or sinus at the margin near its junction with the pillar. Distribution, 3 species. Carboniferous. Indiana. 24 GASTEROPODA. [FAMILY VERMETIDZ. | The shells of species of this family are distinguished from those of the Serpule by the presence of a spiral nucleus and of concave smooth interior septa. If the shell is formed of a solid matter strongly sculptured with longitudinal grooves or scales, or of a brownish colour, it is certainly formed by a Vermetus; but if the shell is of a soft earthy matter, feebly longitudinally grooved, it is deubtful to which it belongs. The shells of the Serpulide have an anal opening (except Cymospira), and appear only to be composed of two layers, the Vermetide haying three. The interior of several species contains very long lamellz, generally regarded of generic value; but they are dissolved with age, like the teeth of some species of Pupa. All the Vermeti are viviparous, and the lamelle within the tubes may serve for the retention of the fry. The genera and sub-genera contained in this family are VER- METUS (Petaloconchus, Serpulorbis) (p. 249), and SILIQUARIA (p. 249). [Faminy Cacrp&. | Shell with a spiral nucleus; tubular, regular, sometimes fixed aperture orbicular ; ; operculum horny, multispiral ; margin sometimes fimbriated. CzacumM, Fleming.* Nuclear whorls orbicular, in the same plane as the adult, fre- quently decollated; operculum concave or flattened. Sections :—EHlephantulum. Comparatively of large size, tapering; sculpture longitudinal. Distribution, 9 species. Mazatlan (6), West Indies, Mauritius. Fossil, 1 species (C. liratum), Carpenter. Cor. Crag. Sutton. Anellum (typical Czeca). Adult shell annulated. Distribution, 14 species. Europe, Matzatlan, Australia, Japan. Fossil, 2 species. Hocene. Paris, Suffolk. Fartulum. Smooth, cylindrical. Distribution, 10 species. . Mazatlan, Teneriffe, Singapore, Australia. Fossil, C. mamillatum, 8. Wood. Cor. Crag. Sutton. Sub-genera :—BROCHINA, Gray. Type, Dentalium glabrum, Mont. * See p. 249, Cc bo Ou MANUAL OF THE MOLLUSCA. Shell like Coecum, smooth; aperture simple, acute; apex closod by a mamillated plug; operculum, convex. Distribution, 2 species. Europe, West Indies, Mazatlan. MEIOCERAS, Carpenter. Etymology, meion, rather small; ceras, horn. Young shell spiral or flat; adult somewhat inflated; aperture oblique; operculum spiral, scarcely concave. Distribution, 3 species. West Indies. STREBLOCERAS, Carpenter, 1858. Etymology, streblos, twisted; ceras, horn. Shell with the spire not decollated, no plug formed; nuclear whorls orbicular, perpendicular to the plane of the adult; the plane of growth is flat, asin Cecum, but some examples haye a slight twist, forming an approach to Meioceras. Fossil, 4 species. Hocene. Hampshire, Paris. Faminty V.—TURRITELLIDZA* Includes TURRITELLA, PROTO, MESALIA, and CASSIOPE, Coquand, 1865. Synonym, Omphalia, Zekeli, 1852 (non Omphalius, Philippi, 1847). Example, Turritella Renauxiana, D’Orbigny. Shell thicker, and with more rapidly increasing whorls than in Turritella, often pupiform; aperture rounded, continuous; outer lip notched or sinuated by an impressed furrow, which winds round the last whorl; columella usually distinctly um- bilicated. Distribution, 32 species. Cretaceous. Europe, India, and America. _ [Faminy ScALARIADAT | Includes ScALARIA and the sub-genera Lglisia, Pyrgiscus, and Cirostrema, Morch. Shell solid, varices irregular, whorls generally cancellated. CocHLEARIA, Braun. Synonym, Chilocyclus, Bronn. * See p. 248, T See p. 250. 26 GASTEROPODA. Shell turriculated, thick; aperture circular, continuous, with a large expanded border. Fossil, 2 species. Saint Cassian beds, Austria. HOLOPELLA, McCoy, 1882. Evample, H. gregaria, Sow. (Turritella), Sil. Syst. t. 3, f. 1. Htymology, ’olos, entire, and ope, an aperture. Shell elongated, slender, of numerous gradually increasing whorls, generally crossed by slightly arched strize; mouth cir- cular, with the peristome entire; base rounded, with or without a minute umbilicus. The shells of the species composing this genus differ from those of .Turritella in the continuous peristome and definite round margin to the aperture, thus approaching much nearer to Scalaria. Fossil, 12 species. Silurian—Trias. Europe, United States. Famity [TV.—MELANIADZ.* MELANIA.—Tentacles long, with eyes on the exterior side at about a third of the length; margin of the mantle festooned. Sub-genera, Vibex, Melanatria, Hemsinus, and Philopotamis, Layard, P. sulcata, Reeve, sp. Operculum sub- spiral; nucleus marginal. Shell solid, paludiniform. Distribu- tion, 5 species. Ceylon. Habit of Tanalia. PaLupomus (Type, P. conicus, Gray), as restricted by the separation of Philopotamis and Tanaiia, is characterised by the conceutric structure of the adult operculum resembling that of Paludina, and a spiral nucleus situated about the middle of its height, and nearest to the left margin. Distribution, India, Burmah, Egypt, Kast Indian Archipelago, Mauritius, Ceylon (2 species, reduced from 14). In tanks and marshes. Sub-genus, Tanalia, Gray. Synonym, Ganga, Layard, founded upon certain monstrous forms of TZ’. aculeata. Type, T. aculeata Chemnitz. Shell semiglobose, costate, nodulose; mouth very large, ovate; operculum unguiculate; nucleus marginal. Distribution, 2 species. Inhabiting mountain streams, ad- hering to rocks, or crawling over sandy bottoms, Ceylon. Fossil, 2 species. Upper Chalk. Gosau * See p. 246, &c. c2 27 MANUAL OF THE MOLLUSCA. Io, Lea, 1831. Synonyms, Melafusus and Ceriphasia, Swainson; Pleurocera and Strepoma, Raf.; Trypanostoma, Lea; Telescopella, Gray. Type, I. fluvialis, Say (Fusus). Animal with the mantle margin plain; eyes at the base of the tentacles, which are short; operculum subspiral. Shell fusiform, inflated, conical or oval; aperture produced into a more or less obvious canal in front. Distribution, 100 species. North America. Sub-genera, Lithasia, Haldeman, 1840. Synonyms, Angi- trema, Haldeman ; Potodoma, Sw.; Glotella, Gray. Columella callously thickened. above and below; base of aperture notched. Distribution, 31 species. North Andover: Strephobasis, ea, 1861 (Megara sp., A. and H. Adams). Shell with a retorse canal at the base of the squarish aperture. Distribution, 8 species. North America. GYROTOMA, Shuttleworth, 1845. Synonyms, Gontobasis, Lea, 1862; Huryccelon, Lea. Shell solid, oval, oblong, or turreted ; many forms resemble Paludomus; aperture subrhomboidal, subangular in front, without a canal; columella frequently callously thickened above; operculum subspiral, as in Melania. Distribution, 289 species. United States. Fossil, 8 species. Eocene. North America. Sub-genera, Schizostoma, Lea, 1842 (Schizochilus, Lea; Mela- toma carinifera, Anthony); aperture with a slit in the upper part of the outer lip immediately under the suture. Distribu- tion, 27 species. North America. Meseschiza, Lea, 1864. Slit in the middle of the outer lip. M. Grosvenorit. Indiana. PALADILHEA, Bourguignat, 1865. Dedicated to Dr. Paladilhe. Shell somewhat resembling that of Acme; test thin, crystal- line, extremely fragile; base of aperture produced in front; peristome continuous, thin, truncated; outer lip with a slit towards the suture. Distribution, 3 species. Fresh-water deposits. Herault, One of the species is living in the neighbourhood of Montpellier. 28 GASTEROPODA. BucGzEsIA, Paladilhe, 1866. Shell resembling somewhat a very small Cerithiwm or micro- scopic Lithasia, but differing generically in having a wide, compressed, not callous columella like that of Lacuna. Distribution, B. Bourguignati. In washings of the River Lez, Montpellier. . ANcULOSA, Say, 1821. Synonyms, Leptoxis, Rafinesque; Anculotus auctores. Type, A. preemorsus. Shell oval; aperture entire and rounded in front; columella callously thickened above. Distribution, 31 species. North America. MELANOPSIS, including Pirena, see p. 248, W. M., u. Famity VII.—PALUDINID.* The genera contained in this family are— PALUDINA, AMPULLARIA (Pomus, Marisa, Asolene), LANISTES, MELADOMUS, BITHINIA, with the following sub-genera of the last :— Stenothyra (Nematura), Hydrobia, Syncera, Paludinella, Lit- torinella, Amnicola, and MoiITEssIERIA, Bourguignat, 1863. Type, Paludina Simoniana, Charpentier. Shell somewhat similar to that of Acme; test pitted; de- pressions octagonal, tetragonal, and rounded according to their position; peristome externally thickened; no operculum has been observed. Distribution, 1 species. Saline springs at Fouradade (Py- renees). Fossil, 3 species. Alluvium of the river Garonne, at Toulouse. PoMATIopsis, Tyron, 1865. Synonym, Chilocylus, Gill. Shell elongated ; margin of aperture slightly expanded ; oper- culum corneous, subspiral, without an internal process. Animal like that of Hydrobia, but the foot is furnished with lateral sinuses ; terrestrial or amphibious. Distribution, species. America. * See p. 257, &c. 29 MANUAL OF THE MOLLUSCA. [Faminy Risso] Includes LiTiopa (p. 255), Rissorna (p. 256), Rissoa (p. 258), and the following additional genera :— DrastomaA, Deshayes, 1864. Type, Melania costellata, Lamarck. Shell elongated, turreted; whorls with varices; aperture very oblique, semi-lunate, entire; base sinuated, smiitectiien: pos- terior angle acute, detached from the penultimate whorl; lip thin, curved; columella concave, depressed, narrow. Fossil, 4 species. Eocene. Paris basin. AMPHITHALAMUS, P. Carpenter, 1864. Type, A. inclusus. West Coast of North America. Sheli like Rissoa, nucleus large; aperture with a produced lip, suddenly contracted in the adult. This genus bears the same relation to Rissoa that Stoastoma does to Helicina. Kritostoma, Deshayes, 1848. Type, Melania marginata, Lamk. Shell elongated, turriculated, regularly conical; generally striated transversely. Aperture entire, short, effuse at the base, angulated posteriorly; columella short, callous; the peri- stome entire, the left lip broad and thick, the right broadly margined. . Fossil, Hocene, 6 species; Paris basin. Belgium, England, Punjaub. Cretaceous, 5 species; India, Gosau. PTEROSTOMA, Deshayes, 1864. Type, P. tuba. Eocene. Grignon, Paris. Shell elongated, turriculated ; peristome continuous, circular, very dilated and margined; columella very broad, expanded, and continuous with the peristome. ScaLioLa, Adams, 1860. Type, 8. bella. Animal with the rostrum elongated, Petrik annulated, bifid at the end; tentacles filiform, eyes »rominent, black at the outer base of the tentacles; foot short, ovate, posteriorly sub-acuminate; operculum corneous, ovate, suhspiral; nucleus subterminal. jt GASTEROPODA. Shell turreted, umbilicated or rimose; aperture more or less circular; peristome continuous; margin straight, acute. The species have the habit of agglutinating grains of sand to the surface of the shell. Distribution, 4 species. Japan, Philippines, 2—70 fathoms. Fossil, 1 species. Oligocene, Latdorf. MicrostELMA, A. Adams, 1863. Type, M. Deedala, Adams. Japan, 48 fathoms. Shell turreted, ovate, rimose, somewhat resembling Pyrami- della ; spire conical; whorls longitudinally plicated. Aperture oblong, produced in front, sub-canaliculate; columella thick- ened, straightish ; lip simple. Fossil, 1 species. Sub-apennine formation. Asti, Italy. BARLEEIA, Clark. Named in honour of the late G. Barlee. Type, Turbo ruber, Montagu. Britain, Mediterranean. Animal and shell related to Rissoa ; mantle and opercular lobe destitute of filaments; operculum solid, auriform, and gibbous, nucleus excentric. Distribution, 3 species. Atlantic and Pacific Oceans. [FAMILY SKENEIDZ | Includes Skenea (p. 256), and HomaALoGyRa, Jeffreys, 1867. Synonyms, Omalogyra, Jeffreys; Spira, Brown; Ammoni- cerina, Costa, 1861. Etymology, a flat circle. Tyve, H. atomus, Philippi (Skenea nitidissima, F. and H.). Animal with a flattened body, no tentacles ; eyes sessile, and placed behind the head. Shell minute, forming a flat coil; spire involute; whorls more or less angulated ; mouth clasping both sides of the peri- phery ; operculum few-whorled, with a central nucleus. The upper part of the body of H. atomus is partially ciliated. The tongue has only a single row of teeth, resembling miniature shark’s teeth. Distribution, 2 species. In pools, and just beyond low water, on sea-weeds and Zostera. Norway, Britain, France, shores of the Mediterranean. Fossil, upper tertiary deposits. . 31 MANUAL OF THE MOLLUSCA. Faminty VI.—LItTToORINIDZ.* The genera are— Lirrormva, including Tectaria, Modulus, and Risella ; LAcUNA, and Fossarus, Philippi (p. 253). Synonyms, Phasianema, Wood; Maravignia, Arados. Shell perforated, sculptured ; inner lip thin; aperture semi- lunate; operculum not spiral. Animal with two frontal lobes between the tentacles. Distribution, 43 species, including species of the sub-genera. Mediterranean and tropical seas. Fossil, 4 species. Miocene. Europe. Sub-genera, Conradia, Couthouyia, Cithna, Gottoina. Fossarina, Adams, differs from Fossarus in the curyed inner lip and circular aperture. 2 species. Australia. Isapis, H.and A. Adams. Columella with a plait; in J. anomala it is almost obsolete. 4 species. Jamaica and Mazat- lan. LACUNELLA, Deshayes, 1864. Etymology, diminutive of Lacuna (see p. 255). Type, Li. depressa, Desh. Eocene. Paris. Shell ovate, thin, pellucid, shining, very depressed; apex obtuse; aperture large, dilated; outer lip thin, reflected; colu- mella narrow, thin, concave, grooved, with the base perforated. P RAULINIA, Mayer, 1864. Dedicated to M. Raulin. Type, Odostomia alligata, Deshayes. Eocene. Paris basin. Shell turbinated, oval-oblong, moderately thick, spirally sul- cated; whorls rapidly increasing, convex; last whorl very large; aperture large, angulated posteriorly, expanded in front; columella broad, arcuate, flattened, with a prominent tuber- culous tooth. Evucyctius, E, Deslongchamps, 1860. Etymology, eu-kuklos, circling, in allusion to the numerous plications or rings of the spire and base. Examples, Turbo ornatus, Sow. ; T. capitaneus, Mist. * See p. 250. 32 GASTEROPODA. Synonym, Amberleya,* Morris and Lycett. Shell very thin (without a nacreous layer?); spire elongated, almost turriculated ; surface ornamented by longitudinal plica- Fig. 14. Hucyelus goniatus, Desi.. tions and nodes; aperture oval, angular above; lip semi- circular, thin; columella flattened, imperforated. Fossil, 23 species. Upper Lias— Kelloway Rock. England, France, Germany. [FAMILY SOLARIDE | Contains— SOLARIUM (see p. 253). Sub-genera, Torinia, Gray. Philippia, Gray (p. 253). Shell trochiform ; umbilicus small. Fossil, 3 species. Miocene. America. Disculus, Deshayes. Shell discoid; umbilicus very narrow, inferior angle of the aperture extended and oblique. ADEORBIS (p. 266), Cirrus (p. 271), DIscoHELIXx (p. 253), HKUOMPHALUS (pp. 267, 346), BIFRONTIA (p. 253), PLATYSTOMA (p. 254), PHANEROTINUS (p. 267), MACLUREA (p. 345). * This name was published in 1854, but the genus was insufficiently characterised. c3 33 MANUAL OF THE MOLLUSCA. OPHILETA, Vanuxem (p. 267), was founded on species of Maclurea, with very slender whorls. Mr. Billings regards them as distinct, and distinguishes them as follows :—‘‘ In Maclurea the aperture is entire, and the whorls usually large, but in Ophileta it has a sinus below and a notch above, while the whorls are usually more slender. “In Maclurea crenulata (Billings) there isa sort of spiral band, and also there are indications of a sinus in the lip on the flat side, but they are only incipiently developed.” —(Billings.) STROPHOSTYLUS, Hall. Etymology, strepho, I turn, and stylus, columella. Shell subglobose or ovoid ; spire small, body whorl large and ventricose; outer lip thin; columella twisted or spirally grooved within, not reflected; umbilicus wanting; aperture ovate or transversely oval; apparently related to Platystoma. Distribution, 10 species. Silurian. United States. HEtiocryprus, D’Orbigny, 1850. Shell depressed, orbicular; whorls embracing; umbilicated on both sides; aperture vertical, oval transverse. Distribution. H. pusillus, Coral Rag, France, Germany ; A. radiatus, U.G.S. Blackdown, Mans. [Famity JANTHINIDE ] Includes— JANTHINA and RECLUZIA (see p. 285). FAMILY XII.—CALYPTREZIDA.* PLATYCERAS, Conrad, 1840 (see p. 277). Type, Pileopsis vetusta, Sowerby. Synonyms, Acroculia, Phillips, 1841; Orthonychia, Hall, 1843. Shell depressed, subglobose to oblique, subconical; spire small; whorls few, free or contiguous; aperture more or less expanded, often campanulated, entire or sinuous. Many species show asinuosity of the striz, indicating a notch in the margin of the aperture during the first stages of growth. Mr. Hall has been unable to recognise the peculiar muscular impressions which are characteristic of Pileopsis. Specimens of some species show the expansion of the columellar lip, and its partial or entire union with the volution, presenting all the * See p. 278. 34 GASTEROPODA. appearance of a thin columella with a deep umbilicus. P. dwmosum is spiniferous ; P. swbrectwm is simply bent or arcuate. Distribution, 46 species. Silurian—Carboniferous. Europe, North America. Famity [X.—TuRBINIDE* Includes PHASIANELLA (p. 263), IMPERATOR (p. 264), TURBO (p. 263), with the following sub-genera :— Callopoma, Gray. Distinguished by the extreme complexity of the operculum. ‘‘ The opercula of C. fluctuoswm, Gray (Turbo) (Maz. ), are flat, and covered with a dark horny layer inside, dis- playing about 6 whorls. Outside with a broad, central, spiral callus, white and granular, concealing the umbilicus, with extremely minute pustules over the surface, sometimes with a few sharp prickles. A deeply cut groove surrounds the callus, followed by a green, plaited, spiral frill prickly inside. Between this and the outer margin are 4—6 fine emerald necklaces, sup- ported on slender spiral ribs, with deeply channeled interspaces. The operculum of C. sawoswm, inhabiting Panama, is formed on a much coarser plan.” —(P. Carpenter.) Uvanilla, Gray. Example, U. olivacea, Mexico. Distinguished by the absence of an umbilicus, and the bi- ridged operculum. Distribution, 3 species. Mazatlan, Mexico. PHASIANELLA. Sub-genus, Hucosmia, P. Carpenter, 1864. Hitymology, eu, well, and cosmia, adorned. Shell solid, variegated as in Phasianella ; aperture and whorls round ; axis wmbilicated. Distribution, 4 species. Cape St. Lucas. TROCHUS. With the following sub-genera and sections :— Margarita, Leach (p. 265). Example, T. helicinus, Fabr. Shell small, pearly, and umbilicated ; lateral cirri, 3—7 in British species. No typical Trochi appear to inhabit North-East America, only those of this section. 3 species, Britain. Gibbula, Leach (p. 265). Example, T. magus, Linné. Shell low-spired and umbilicated ; lateral cirri, 3 on each side in the British species. Circulus, Jeffreys. Shell very small, nearly flat-spired, with an exceedingly wide and open umbilicus. Example, Delphinula * See p. 263. 35 MANUAL OF THE MOLLUSCA. Duminyi,* Requien; lateral cirri, 8 on each side (sometimes 4 on one side, and 3 on the other.—Clarke). Fossil, in the Coral- line Crag; Britain; Catania. Living, Britain; Mediterranean. Trochocochlea, Klein. Spire moderately raised ; base, shightly umbilicated in the adult, perforated in the young, pillar lip with a strong tubercular tooth. Lateral appendages 3 to 4 on each side. Example, T. lineatus, Da Costa. Britain, France, Spain, . Mogador. Ziziphinus, Leach. Spire pyramidal, base imperforated ; pillar lip notched or angulated at the lower part. Haxample, i. granulatus, Born. 7 species, Britain. Omphalius, Philippi. Type, Trochus viridulus, Gmel. Mazatlan. Shell with a spiral ridge surrounding the umbilicus, ending in one or more tubercles on the columella. Distribution, 4 species. Mazatlan, China. Pyramnis, Enida, kc. ROTELLA (see p. 265). Sub-genera. Jsanda (I. coronata), Adams. Shell orbicular, conical, pillar edge crenated; whorls rounded; axis umbili- cated ; operculum orbicular, of many whorls. Chrysostoma, Gray. Turbo Nicobaricum, Gmel., related to Isanda. Pillar edge callous; operculum horny, spiral. Microthyca, Adams, differs from Isanda in its continuous peri- stome and thickened outer lip. 1 species, Japan. Umbonella, Adams. Shell porcellanous, smail, turbinated, allied to Chrysostoma, but the aperture is circular, and the axis imperforate. 1 species, Japan. LEUCORHYNCHIA, Crosse, 1867. Etymology, leucon, white; rhynchion, a beak. Type, L. Caledonica, Crosse; inhabits under stones, New Caledonia. Shell depressed, sub-discoid, umbilicated, polished, of few whorls; aperture rounded, not nacreous. 56 0. GREECE, History of, by W. D. Hamilton | and Hi. Levien, M.A. : 26/36 40 7. ROME, History of, by E. Levien, wee Ve 1S | 4-0 9. CHRONOLOGY OF HISTORY, LITE- | rature, Art, and Progress, from the earliest period to the present time : 26/386 40 1l. 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