1 History. an inconvenient magnitude, the class of Vermes which will be treated of in its proper place in the course of the work.
2 Importance of conchology. The fine polish, splendid colours, and elegant form of shells, have been long admired, and have procured for them a conspicuous place in the cabinets of the curious. Indeed in this respect, mankind have discovered no small degree of folly and extravagance, in the high price which has been given for rare and beautiful shells, and often only on account of their rarity. But the study of conchology acquires a higher degree of importance and utility in another view. In many parts of the world, different kinds of testaceous animals are employed as an excellent and nutritious food; and some tribes supply the table with a delicate luxury. Different shells furnish employment to ingenuity and art, in the manufacture of mother-of-pearl for various purposes; and the pearl itself, so much sought after as an ornament of dress, and often the rival of the richest
3 History. gems, in the estimation of mankind, is the production of testaceous animals. Its nature and mode of formation, therefore, cannot fail to be objects of curious investigation. But testaceous animals and their productions, are not only beneficial and ornamental; some are found to be highly pernicious. The snail ravages the garden and the field, and marks its progress with the destruction of some of the fairest of the vegetable tribes; while the ship-worm is justly the dread of the mariner; feculence, as it were, in its insignificance, humbles the glory and pride of man; and labouring in secret, demolishes the noblest efforts of ingenuity. In these views, then, the economy and habits of testaceous animals, which at first sight might appear a barren and useless pursuit, become an important and beneficial subject of investigation. The following chapters, therefore, shall be occupied in the classification and natural history of this tribe of animals.
CHAP. I. HISTORY OF CONCHOLGY.
3 Cultivated by the ancients. THE few scattered fragments concerning the natural history of shells, or testaceous animals, which are to be found in the writings of the ancients, when compared with the more extended and systematic labours of the moderns, are so unimportant and inaccurate, that it would be altogether superfluous to trouble our readers with an account of the information which they contain. It appears, however, from the works of Aristotle and Pliny, the great naturalists of Greece and Rome, that the study of conchology was not entirely neglected in their time. It appears too, that admirers and collectors of shells were not then wanting. Scipio and Lælius, we are informed, found a relaxation from the toils and cares of war and government, by indulging in this elegant amusement (A).
4 By the moderns. Nor will it be attended with much advantage, to give a particular account of the works of the earlier writers on this subject, among the moderns. These are Gesner, Johnston, Rondeletius, Aldrovandus, Belonius, Wormius, and some other authors, who cultivated this department of natural history, and accompanied their descriptions with figures, illustrative of the objects which they described.
The first author who attempted a systematic division of shells, according to their external form and characters, was John Daniel Major, professor of medicine in the university of Kiel in Holstein. His method is published at the end of his curious and interesting remarks on the treatise concerning the purpura of Fabius Columna, printed at Kiel in 1675. The system of the German naturalist was followed by that of our countryman Dr Lister, on a more extended and improved plan, which was published ten years after. Succeeding naturalists turned their attention to the study of conchology, and to the improvement of the classification of the numerous objects of this department of natural hi-
story. Such were Buonanni, Rumfus, Langius, Breynius, Tournefort, Gualtieri, D'Argenville, Klein, Linnæus, Adanson, Geoffroy, and Müller.
We shall here exhibit some of the most celebrated systems of conchology which have been proposed by writers on this subject. This, we trust, will not be unacceptable to our readers, and particularly as the works of these authors are in few hands, and therefore become less accessible.
5 I. The first general arrangement of shells is that System of Lister, published by Dr Lister in a work with the following title. Martini Lister, M. D. Historia sive Synopsis methodica Conchyliorum libri quatuor, continentur 1057 figuræ ære nitidissime incisæ, a Susanna et Anna Lister depictæ. Londini, 1685—1688, folio. A second edition of the same work was published at Oxford in 1770, with additional figures.
SYSTEM OF LISTER.
Lia. I. De Coelebis Terrestribus.
PARA I. De Buccinis et Turbinibus terrestribus.
Secl. 1. De Buccinis terrestribus a sinistra dextrorsum tortilibus, lœvis, edentulis.
Secl. 2. De Buccinis terrestribus a sinistra dextrorsum tortilibus, edentulis, striatis.
Secl. 3. De Buccinis terrestribus a sinistra dextrorsum tortilibus, apertura dentata.
Secl. 4. De Buccinis terrestribus a dextra sinistrorsum tortilibus, apertura plana.
Secl. 5. De Buccinis terrestribus a dextra sinistrorsum tortilibus, apertura dentata.
Secl. 6. De Turbinibus terrestribus cochleæformibus, id est compaetiore figura.
Secl.
(A) Lælium et Scipionem conchas et umbilicos ad Cæjetam et ad Laurentum legere consueisse, et ad omnem animi remissionem ludumque descendere. Cic. de Orat. lib. ii.
edentulo. Cap. 5. De Neritis edentulis lœvibus.
Cap. 6. De Neritis edentulis muricatis.
Secl. 7. De Auribus marinis.
Secl. 8. Cap. 1. De Trochis pyramidalibus, apertura five basi leviter tumida. Cap. 2. De Trochis pyramidalibus, basi paululum cava five sinuata. Cap. 3. De Trochis, apertura five basi plana. Cap. 4. De Trochis brevioribus, umbilicatis, dentatis. Cap. 5. De Trochis cochleiformibus, umbilicatis, edentulis. Cap. 6. De Trochis clavicula breviori, columella paulo erectiore integra. Cap. 7. De Trochis, basi media leviter tumida, quasi altera clavicula. Cap. 8. De Trochis, unico dente ad columellam acuto.
Secl. 9. Cap. 1. De Conchis venereis unicoloribus. Cap. 2. De Conchis venereis, lineis nigris secundum longitudinem depictis. Cap. 3. De Conchis undatim depictis. Cap. 4. De Conchis venereis fasciatis, immaculatis; et de conchis venereis fasciatis et maculatis, aut alias cum fasciis variegatis. Cap. 5. De Conchis venereis, punctis nigris distinctis. Cap. 6. De Conchis venereis, maculis albis nigrisque interspersis insignitis; et de conchis venereis maculis albis quasi reticulatim depictis. Cap. 7. De Conchis venereis, striis eminentibus conspicuis. Cap. 8. De Conchis venereis, punctis elatis exasperatis, nodisque inaequalibus. Cap. 9. De Conchis venereis, apertura non dentata, basi integra. Cap. 10. De Conchis venereis, basi umbilicata cochleata.
Secl. 10. Cap. 1. De Rhombis cylindraceis columella dentata, crassis, unius coloris. Cap. 2. De Rhombis cylindraceis dentatis, maculosis. Cap. 3. De Rhombis cylindraceis dentatis, fasciatis. Cap. 4. De Rhombis cylindraceis dentatis, undatis. Cap. 5. De Rhombis cylindraceis dentatis, dorso gibboso. Cap. 6. De Rhombis cylindraceis edentulis, ore strictiore. Cap. 7. De Rhombis edentulis tenuibus, ore patulo, clavicula paululum exerta. Cap. 8. De Rhombis edentulis, ore patulo, clavicula compressa.
PART II. Cap. 1. De Rhombis cylindrico-pyramidalibus, unius coloris. Cap. 2. De Rhombis cylindrico-pyramidalibus, quibus lineæ maculate circum injiciuntur. Cap. 3. De Rhombis cylindrico-pyramidalibus, striatis. Cap. 4. De Rhombis cylindrico-pyramidalibus, undatis. Cap. 5. De Rhombis cylindrico-pyramidalibus, fasciatis. Cap. 6. De Rhombis cylindrico-pyramidalibus, reticulatis. Cap. 7. De Rhombis cylindrico-pyramidalibus, dentatis.
Secl. 11. Cap. 1. De Buccinis perficis dictis. Cap. 2. De Buccinis muscis dictis. Cap. 3. De Buccinis columella dentata, clavicula longissima et tenuissima.
Secl. 12. Cap. 1. De Buccinis bilinguibus, lœvibus. Cap. 2. De Buccinis bilinguibus, striatis. Cap. 3. De Buccinis bilinguibus, asperis et muricatis. Cap. 4. De Buccinis bilinguibus, digitatis.
Secl. 13. Cap. 1. De Buccinis ampullaceis lœvibus, aut certe minus asperis. Cap. 2. De Buccinis ampullaceis, muricatis. Cap. 3. De Buccinis ampullaceis, ad sinistram convolutis.
Secl. 14. Cap. 1. De Buccinis utrinque productioribus, lœvibus. Cap. 2. De Buccinis utrinque productioribus, striis densis et tenuioribus exasperatis. Cap. 3. De Buccinis utrinque productioribus, striis pauciori-
bus donatis, labro simplici. Cap. 4. De Buccinis utrinque productioribus, striis paucioribus, labro duplicato donatis. Cap. 5. De Buccinis utrinque productioribus, muricatis.
Secl. 15. Cap. 1. De Buccinis brevirostris, nodosis. Cap. 2. De Buccinis brevirostris, striatis. Cap. 3. De Buccinis brevirostris, lœvibus, fere clavica produciore. Cap. 4. De Buccinis brevirostris, labro repando, tenuibus. Cap. 5. De Buccinis brevirostris, labro repando, crassis. Cap. 6. De Buccinis brevirostris, compressis. Cap. 7. De Buccinis auritis, five rostro recurvo donatis, ventriculosis. Cap. 8. De Buccinis brevirostris, sinu reflexo, lœvibus. Cap. 9. De Buccinis brevirostris, rostro reflexo, clavicula produciore.
Secl. 16. Seu appendix de buccinitis, iisve lapidibus que buccina omnigena valde referant.
II. In 1722, Langius presented to the world the following work on conchology. Caroli Nicolai Langii Lucernen. Helvet. Phil. et Med. Sc. Methodus nova, et facilis testacea marina pleraque, que huc usque nobis nota sunt, in suas debitas et distinctas classes, genera, et species, distribuendi, nominibusque suis propriis, structura potissimum accommodatis nuncupandi, &c. Lucerna, 1722. 4to. p. 102.
SYSTEM OF LANGIUS.
PART I. Testacea marina univalvia non turbinata.
CLASSIS PRIMA. Testacea marina univalvia non turbinata, et in se non contorta.
Secl. 1. Testacea marina univalvia non turbinata, et in se non contorta nullo modo, vel solummodo in summo apice tantillum incurvata. Gen. 1. Patellæ. Gen. 2. Balani.
Secl. 2. Tubuli marini, seu testacea marina univalvia, non turbinata, et in se non contorta, elongata tubuli instar concava. Gen. 1. Penicilla. Gen. 2. Dentales. Gen. 3. Tubuli radiciformes. Gen. 4. Tubuli vermiculares.
CLASSIS SECUNDA. Testacea marina univalvia, non turbinata, sed ita in se contorta, ut eorum spiræ non prominent.
Secl. 1. Testacea marina univalvia ita in se transversim, vel oblique secundum longitudinem contorta, ut eorum circumvolutiones vix appareant. Gen. 1. Nautili. Gen. 2. Nuces marinas.
Secl. 2. Porcellanæ, seu testacea marina univalvia non turbinata. Gen. 1. Porcellanæ vulgares. Gen. 2. Porcellanæ fimbriatæ. Gen. 3. Porcellanæ spirales. Gen. 4. Porcellanæ thoracicæ. Gen. 5. Porcellanæ minores integrie.
Secl. 3. Divis. 1. Cornua ammonis, quæ sunt testacea marina univalvia non turbinata, et serpentum in modum in se contorta, ut eorum circumvolutiones nulla ex parte prominent, et tamen ex utroque latere omnes apparent. Gen. 1. Cornua ammonis unita. Gen. 2. Cornua ammonis anomala. Divis. 2. Gen. 1. Cornua ammonis simpliciter divisa. Gen. 2. Cornua ammonis integre divisa.
PARS SECUNDA. Cochleæ marinæ, seu testacea marina univalvia turbinata, quæ unica tantum constant valva et figura sua cochlearum in modum intorta sunt, ita ut intima eorum spira aliquo saltem modo promineat et producatur.
CLASSIS PRIMA. Cochleæ marinæ longæ, seu cochleæ marinæ ore admodum elongato et superius aperto.
SECT. 1. Cochleæ marinæ longæ ore labiis rectis. Gen. 1. Cochleæ pyramidales. Gen. 2. Cochleæ cylindroides.
SECT. 2. Cochleæ longæ pyriformes, seu cochleæ marinæ longæ ore labiis leviter incurvatis, ideoque etiam leviter ventricosis. Divis. 1. Cochleæ longæ pyriformes minores, vulgares. Gen. 1. Cochleæ longæ pyriformes minores intortæ integræ. Gen. 2. Cochleæ longæ pyriformes minores intortæ et infulcatæ. Divis. 2. Cochleæ longæ pyriformes majores. Gen. 1. Cochleæ longæ pyriformes majores vulgares. Gen. 2. Cochleæ longæ pyriformes majores, intortæ integræ. Gen. 3. Cochleæ longæ pyriformes majores intortæ cylindroides.
CLASSIS SECUNDA. Cochleæ canaliculatæ, seu cochleæ marinæ ore elongato et superius in canaliculum abeunte.
SECT. 1. Cochleæ marinæ canalicula recta. Gen. 1. Cochleæ canaliculatæ rectæ tenuiores. Gen. 2. Cochleæ canaliculatæ rectæ crassiores. Gen. 3. Purpureæ rectirostræ.
SECT. 2. Cochleæ marinæ canaliculatæ incurvatæ. Gen. 1. Cochleæ canaliculatæ introrsum incurvatæ. Gen. 2. Cochleæ canaliculatæ extrorsum incurvatæ. Gen. 3. Murcicus. Gen. 4. Cochleæ muriciformes insigniter incrispatæ. Gen. 5. Purpureæ curvirostræ. Gen. 6. Cochleæ cassidiformes umbilicatæ. Gen. 7. Cassidæ.
CLASSIS TERTIA. Buccina sunt cochleæ marinæ ore et mucrone simul elongatis, primaque spira notabiliter ventricosa.
SECT. 1. Buccina parva mucrone mediocriter elongato et tenuiter acuminato. Gen. 1. Buccina parva pruniformia acuminata. Gen. 2. Buccina parva pruniformia canaliculata. Gen. 3. Buccina parva curvirostra. Gen. 4. Buccina parva sulcata. Gen. 5. Buccina parva sulcata et canaliculata. Gen. 6. Buccina parva integra ore perpendiculari. Gen. 7. Buccina parva integra ore obliquo.
SECT. 2. Buccina majora, quæ sunt buccina mucrone admodum elongato et acuminato. Gen. 1. Buccina majora canaliculata rostrata, ore simplici. Gen. 2. Buccina majora canaliculata, ore labioso. Gen. 3. Buccina majora canaliculata rostrata, ore labioso, fimbriata. Gen. 4. Buccina majora canaliculata et sulcata.
CLASSIS QUARTA. Strombi, qui sunt cochleæ marinæ ore et mucrone simul insigniter elongatis, et prima spira notabiliter angustiore quam in buccinis.
SECT. 1. Strombi ore superius aperto. Gen. 1. Strombi
canaliculati acuminati. Gen. 2. Strombi canaliculati rostrati, ore simplici. Gen. 3. Strombi canaliculati rostrati, ore anguloso. Gen. 4. Strombi canaliculati rostrati, ore labioso. Gen. 5. Strombi sulcati vulgares. Gen. 6. Strombi sulcati, ore labioso.
SECT. 2. Strombi integri, ore superius clauso, seu integro. Gen. 1. Strombi integri vulgares, ore simplici. Gen. 2. Strombi integri, ore labioso. Gen. 3. Strombi integri, ore fimbriato et dentato.
CLASSIS QUINTA. Cochleæ marinæ, ore admodum brevi seu parvo, mucrone vero insigniter elongato.
SECT. 1. Turbinæ aperti, seu cochleæ marinæ ore admodum brevi seu parvo superius aperto, mucrone longissimo. Gen. 1. Turbinæ aperti. Gen. 2. Turbinæ aperti acuminati. Gen. 3. Turbinæ aperti canaliculati recte rostri. Gen. 4. Turbinæ aperti canaliculati oblique incurvati. Gen. 5. Turbinæ aperti sulcati.
SECT. 2. Turbinæ integri, ore superius clauso seu integro. Gen. 1. Turbinæ integri vulgares. Gen. 2. Turbinæ integri acuminati. Gen. 3. Turbinæ integri fimbriati.
SECT. 3. Trochi seu cochleæ marinæ ore admodum brevi, seu parvo e basi lata et quasi plana in mucronem quasi rectilineam conoideum insigniter elongatum abeuntes. Gen. 1. Trochi ore angusto et horizontaliter compresso. Gen. 2. Trochi ore ampliore et subrotundo.
CLASSIS SEXTA. Cochleæ marinæ breviores, seu cochleæ marinæ ore et mucrone breviori magisque contracto.
SECT. 1. Cochleæ breviores proportionatæ. Gen. 1. Cochleæ trochiformes breviores proportionatæ et mucronatæ. Gen. 2. Cochleæ marinæ terrestri-formes breviores proportionatæ. Gen. 3. Cochleæ depressæ.
SECT. 2. Cochleæ marinæ breviores perpendiculariter anomalæ. Gen. 1. Neritæ. Gen. 2. Cochleæ umbilicatæ foramine spirarum semicirculari. Gen. 3. Cochleæ umbilicatæ foramine spirarum rotundo.
SECT. 3. Cochleæ marinæ breviores horizontaliter anomalæ. Gen. 1. Cochleæ planæ. Gen. 2. Aures marinæ.
SECT. 4. Varia hucusque enarratarum cochlearum opercula quæ aut propter usum aut propter singularem structuram, magis nota sunt. Gen. 1. Opercula cochlearum marinarum subrotunda. Gen. 2. Ungues marini, seu opercula cochlearum marinarum oblonga.
PARS TERTIA. Conchæ marinæ, id est testacea marina bivalvia quæ duabus constant valvis in cardine, articulatione quadam inter se conjunctis, ut commode claudi et operiri queant.
SECT. 1. Conchæ marinæ notabiliter umbonatæ et rectæ incurvatæ. Gen. 1. Conchæ marinæ valvis æqualibus æquilateræ. Gen. 2. Conchæ cordiformes umbone cardinum deducto. Gen. 3. Conchæ marinæ cordiformes æquilateræ, umbone cardinum unito.
SECT. 2. Conchæ marinæ valvis æqualibus æquilateræ leviter umbonatæ. Gen. 1. Conchæ crassæ. Gen. 2. Pectinæ.
Pectines tenues. Gen. 3. Pectunculi. Gen. 4. Conchæ pectiniformes æqualiteræ subrotundæ. Gen. 5. Conchæ pectiniformes æqualiteræ.
Secl. 3. Conchæ marinæ valvis æqualibus æqualiteræ, notabiliter umbonatæ et oblique incurvatæ. Gen. 1. Conchæ marinæ incurvatæ subrotundæ vulgares. Gen. 2. Chamæ æqualiteræ.
Secl. 4. Conchæ marinæ, valvis æqualibus æqualiteræ leviter umbonatæ et oblique incurvatæ. Gen. 1. Conchæ marinæ valvis æqualibus subrotundæ. Gen. 2. Tellinæ æqualiteræ.
Secl. 5. Pinnæ, seu conchæ marinæ valvis æqualibus æqualiteræ, cardine umbone destituto. Gen. 1. Pinnæ rectæ. Gen. 2. Pinnæ incurvatæ.
CLASSIS SECUNDA. Conchæ inæqualiteræ, seu conchæ marinæ valvis æqualibus ex utroque cardinis latere inæqualiter effusæ.
Secl. 1. Conchæ marinæ valvis æqualibus inæqualiteræ notabiliter umbonatæ, et rectæ incurvatæ. Gen. 1. Conchæ marinæ valvis æqualibus inæqualiteræ subrotundæ. Gen. 2. Conchæ marinæ cordiformes inæqualiteræ, umbone cardine deducto. Gen. 3. Conchæ marinæ cordiformes inæqualiteræ, umbone cardinum unito.
Secl. 2. Conchæ marinæ valvis æqualibus inæqualiteræ, leviter umbonatæ et rectæ incurvatæ. Gen. 1. Conchæ marinæ leviter umbonatæ et rectæ incurvatæ subrotundæ.
Secl. 3. Conchæ marinæ valvis æqualibus inæqualiteræ, notabiliter umbonatæ et oblique incurvatæ, subrotundæ vulgares. Gen. 1. Chamæ inæqualiteræ. Gen. 2. Conchæ rhomboidales.
Secl. 4. Conchæ marinæ valvis æqualibus inæqualiteræ leviter umbonatæ et oblique incurvatæ. Gen. 1. Conchæ marinæ, &c. subrotundæ. Gen. 2. Conchæ pectiniformes inæqualiteræ triangulares. Gen. 3. Tellinæ inæqualiteræ. Gen. 4. Conchæ tellinæformes. Gen. 5. Musculi. Gen. 6. Conchæ longæ rugosæ. Gen. 7. Conchæ soleniformes. Gen. 8. Mytili.
Secl. 5. Conchæ marinæ valvis æqualibus inæqualiteræ, leviter umbonatæ et oblique incurvatæ, structura et striis peculiaribus. Gen. 1. Conchæ imbricatæ. Gen. 2. Pholades. Gen. 3. Daçyli. Gen. 4. Hylleroconchæ. Gen. 5. Conchæ alæformes. Gen. 6. Conchæ quadratæ.
Secl. 6. Conchæ inæqualiteræ non umbonatæ, seu conchæ marinæ valvis æqualibus inæqualiteræ, cardine umbone destituto. Gen. 1. Solenes. Gen. 2. Conchæ marinæ, &c. structura peculiari.
CLASSIS TERTIA. Conchæ anomalæ, seu conchæ marinæ valvis inæqualibus.
Secl. 1. Conchæ marinæ anomalæ umbonatæ et auritæ. Gen. 1. Pectines anomalæ. Gen. 2. Spondyli.
Secl. 2. Ostreæ, seu conchæ marinæ anomalæ omnino non vel irregulariter tantum umbonatæ rugosæ. Gen. 1. Ostrea vulgaris. Gen. 2. Ostrea denticulata. Gen. 3. Ostrea rostrata. Gen. 4. Ostrea peculiaris.
III. A different system was proposed for the classification of testaceous animals by Breynius, in the following work, which was published in the year 1732.
Joannis Philippi Breynii dissertatio physica de polybalaanis, nova testaceorum classe, cui quædam præmituntur de methodo testacea in classes et genera distribuendi: huic adjicitur commentatiuncula de belemnitis prussicis, tandemque schediaisma de Echinis methodice disponendis; Gedani, 1732, 4to.
In this system the author has divided shells into the eight following classes, viz. 1. Tubulus. 2. Cochlidium. 3. Polythalamium. 4. Lepas. 5. Concha. 6. Conchoidea. 7. Balanus. 8. Echinus.
1. Tubulus, est testa tubulosa monothalamia, vel in lineam rectam extensa, vel incurva, vel contorta, vel aliquando ad spiram, sed irregulariter, accedens. Huic pertinent dentalia, entalis, solenes univalvi, &c.
2. Cochlidium, est testa tubulosa, monothalamia, conica, inspirans constantem regularem, convoluta aliquando opercula prædita, sepius vero eo destituta. Ad hanc classem spectant nautili tenues five vacui vulgo dicti; aures marinæ, neritæ, cochleæ, buccina, murices, cassides, cylindri, volutæ, porcellanæ, et omnes testæ turbinatæ, exceptis nautilo et anomia, ad classem tertiam referendis.
3. Polythalamium, est testa tubulosa polythalamia, conica, recta, vel in spiram regularem convoluta, cum syphunculo thalamos transeunte: huic reducendi nautili, anomia, litui, et orthocerata.
4. Lepas, est testa vasculosa, simplex, referens vasculum magis minusve cavum, orificio multum patenta, ut patellæ simileque.
5. Concha, est testa vasculosa composita, bivalvis, id est que ex duabus componitur valvis, five vasculis magis minusve concavis in cardine articulatione quadam inter se junctis ut aperiri et claudi queant; ut chamæ, mytili, tellinæ, pinnæ, ostreæ, pectines anomalæ.
6. Conchoidea, est testa vasculosa composita bivalvis, sed quæ præterea et aliquot minoribus portiunculis testaceis componitur, ut pholades anatifera.
7. Balanus, est testa vasculosa composita, quæ præter unam testam majorem alias portiones minores habet ex quibus componitur, ut balanus vulgo dictus.
8. Echinus, est testa vasculosa composita undique clausa; magis minusve concava, duobus tantum foraminibus seu aperturis pro ore et ano perforata, externe aculeis vel claviculis mobilibus testaceis armata.
IV. The system of Tournefort appeared for the first of Tournefort's time, and was published from the author's manuscript fort. in the treatise on conchology by Gualtieri. In this system shells are divided into three classes, viz. Monotoma, Ditoma, and Polytona.
Testacea dicuntur quorundam animalium integumenta, quæ testæ seu lateris duritiem habent, et in quibus tantum, in testa animalia vivant.
Testacea autem omnia quæ hucusque in musæis curiosorum adversari et congeri solent, ad tres classes facile revocari possunt. Hæc enim vel monotoma sunt, vel ditoma, vel polytona.
Monotoma testacea appellantur ea quorum testa indivisa est; ditoma quæ geminis constant testis ad cardinem
History. dinem connixis; polytoma vero quæ ex pluribus simul adnexis compinguntur.
CLASSIS PRIMA. Quæ testacea monotoma complectitur. Testacea monotoma quorum testa indivisa est, in tres familias abeant: alia enim univalvia sunt, alia spiralia, alia fistulosa.
Familia I. Testaceorum univalvium. Monotoma univalvia dicimus quorum testa simplex est in os amplius effusa. Gen. 1. Lepas. Gen. 2. Eruca.
Familia II. Testaceorum spiraliium. Monotoma spiralia dicimus testacea quorum pars inferior in spiram contorquetur: horum autem spiræ seu helices exteriorius patent, et simpliciter spiralia dicuntur, vel eorum spiræ intus reconditur, et convoluta dicuntur.
Divis. 1. Testacea monotoma simpliciter spiralia, seu quorum spiræ exterior est. Gen. 1. Murex. Gen. 2. Murex alatus. Gen. 3. Murex aporhais. Gen. 4. Murex venereus. Gen. 5. Murex pyramidalis. Gen. 6. Buccinum. Gen. 7. Buccino-murex. Gen. 8. Parpura. Gen. 9. Buccino-parpura. Gen. 10. Peribolus. Gen. 11. Turbo. Gen. 12. Verticillus. Gen. 13. Cochlea. Gen. 14. Cochlea terrestris. Gen. 15. Ceratites. Gen. 16. Cochlea marina. Gen. 17. Nerita. Gen. 18. Auris marina.
Divis. 2. Testacea monotoma spiralia convoluta, quæ cochleam interiorum habent vix foris conspicuam. Gen. 1. Concha venerea. Gen. 2. Concha perfica. Gen. 3. Nautilus. Gen. 4. Conchilus.
Familia III. Testaceorum fistulorum. Testacea monotoma fistulosa seu tubulosa, ut ex nomine patet, fistula in modum tenentur. Gen. 1. Dentale. Gen. 2. Entale. Gen. 3. Tubuli marini.
CLASSIS SECUNDA, quæ testacea ditoma continet. Testaceaditoma semper ex duabus testis ad cardinem articulatis compinguntur, et vel arcte undique clauduntur, vel utrinque hiant; unde in duas familias dividi possunt.
Familia I. Testaceorum ditomorum quæ arcte clauduntur. Gen. 1. Concha. Gen. 2. Conchula. Gen. 3. Ostreum. Gen. 4. Mytilus. Gen. 5. Pinna. Gen. 6. Perna. Gen. 7. Pholas. Gen. 8. Pecken. Gen. 9. Peftunculus.
Familia II. Testaceorum ditomorum quæ semper hiant. Gen. 1. Chame. Gen. 2. Solen.
CLASSIS TERTIA, quæ testacea polytoma continet. Polytoma testacea dicuntur quorum testæ ex pluribus partibus vel articulatis, vel per cartilaginem connexis compinguntur; unde in duas familias abeant.
Familia I. Eorum quorum partes articulatur. Gen. 1. Ichinus.
Familia II. Eorum quorum partes per cartilaginem connectuntur. Gen. 1. Balanus.
V. M. D'Argenville in 1742, published at Paris a treatise on Conchology with 33 plates. A second edition of the same work appeared at Paris in 1757. In this edition the number of the plates was increased to 41. A more splendid edition was published after the death of the author, by M. M. de Favanne de Montecerville father and son. This edition is extended to 3 volumes, two of which consist of letter prefs, and the 3d contains
the engravings, which are 80 in number, and are executed with great accuracy and elegance. But the descriptions of the genera and species only reach the 19th plate; so that the work which was published in 1780 is still unfinished.
SYSTEM OF D'ARGENVILLE.
In this system shells are divided into four parts. I. Sea-shells. II. Fresh-water-shells. III. Land-shells. IV. Fossil-shells.
PART I. Sea-shells are divided into 3 Classes. 1. Univalves. 2. Bivalves. 3. Multivalves.
Class I. contains 15 families; viz. 1. Lepas. 2. Oreilles de mer. 3. Tuyaux et Vermisfeaux de mer. 4. Nautilus. 5. Limaçons à bouche ronde. 6. Limaçons à bouche demi-ronde. 7. Limaçons à bouche aplatie. 8. Cornets ou Volutes. 9. Olives ou Cylindres. 10. Rochers ou Murex. 11. Tonnes. 12. Porcelaines. 13. Buccins. 14. Pourpres. 15. Vis.
Class II. contains 7 families, viz. 1. Huîtres. 2. Cames. 3. Tellines. 4. Moules. 5. Coeurs. 6. Peignes. 7. Manches de couteaux.
Class III. consists of 7 families, viz. 1. Oscabrians, ou lepas à huit pieces. 2. Ourfins. 3. Glands de mer. 4. Pouffe-pieds. 5. Conques anatifères. 6. Pholades. 7. Tuyaux de mer multivalves.
PART II. Fresh water-shells are divided into 2 Classes. 1. Univalves. 2. Bivalves.
Class I. contains 8 families, viz. 1. Lepas. 2. Nautilus ou cornes d'ammon. 3. Limaçons à bouche ronde. 4. Limaçons à bouche demi-ronde. 5. Limaçons à bouche triangulaire. 6. Tonnes. 7. Buccins. 8. Vis.
Class II. is composed of two families. 1. Cames. 2. Tellines.
PART III. Land-shells, constituting a single class, viz. Univalves, which contains 6 families; viz. 1. Lepas. 2. Limaçons à bouche ronde. 3. Limaçons à bouche demi-ronde. 4. Limaçons à bouche aplatie. 5. Buccins. 6. Vis.
PART IV. Fossil shells, which consist of 3 classes. 1. Univalves. 2. Bivalves. 3. Multivalves.
Class I. is composed of 15 families, having the same names as the first class of sea-shells.
Class II. contains 7 families similar to the 2d class of sea-shells.
Class III. consists of 5 families, viz. 1. Ourfins. 2. Glands de mer. 3. Pouffe-pieds. 4. Pholades. 5. Tuyaux multivalves.
VI. A system of Conchology was published by Klein in 1753, and illustrated with engravings. In the same work the author enters into an investigation concerning the formation, increase, and colours of shells. The following is an abridged view of this arrangement.
SYSTEM
In this system, shells are divided into 6 parts.
PART I. which is entitled Cochlis, is divided into 2 sections, viz. Cochlis simplex, and Cochlis Composita.
SECT. I. consists of 8 classes, viz. 1. Cochlis plana, containing 4 genera. 2. Cochlis convexa, 6 genera. 3. Cochlis fornicata, 5 genera. 4. Cochlis elliptica, 6 genera. 5. Cona-cochlis, 16 genera. 6. Cochlea, 8 genera. 7. Buccinum, 5 genera. 8. Turbo, 14 genera.
SECT. II. consists of five classes, viz. 1. Cochlis rostrata, 7 genera. 2. Voluta longa, 15 genera. 3. Voluta ovata, 8 genera. 4. Alata, 6 genera. 5. Murex, 2 genera.
PART II. Concha is also divided into 2 sections, viz. Monoconchæ and Diconchæ æquales.
SECT. I. contains 2 classes, viz. 1. Patella, 2 genera. 2. Anfata, 4 genera.
SECT. II. consists of three subdivisions, viz. 1. Diconchæ conniventes. 2. Diconchæ interruptæ. 3. Diconchæ inæquales.
Subdiv. 1. is composed of 6 classes, viz. 1. Diconchæ figuratæ, 4 genera. 2. Ostreum, 6 genera. 3. Musculus, 3 genera. 4. Cyclas. 5. Diconcha aurita, 9 genera. 6. Diconchæ cordiformes, 3 genera.
Subdiv. 2. consists of 5 classes, viz. 1. Diconcha fulcata. 2. Diconchæ umbilicatæ, 3 genera. 3. Diconchæ sinu profundo, seu chamae, 3 genera. 4. Diconchæ sinu prominulo, seu tellinae, 6 genera. 5. Pyloris, 9 genera.
Subdiv. 3. Diconchæ inæquales, 7 genera.
PART III. Polyconchæ consists only of one genus.
PART IV. Niduli Testacei comprehends one class, viz. Balanus, which includes 4 genera.
PART V. Echinus marinus, seu echinodermata, is divided into 3 sections, viz. 1. Anocyrti. 2. Catocyrti. 3. Pleurocyrti.
SECT. 1. contains 2 classes, viz. 1. Cidaris, 9 genera. 2. Clipeus, 1 genus.
SECT. 2. is composed of four classes, viz. 1. Fibula, 2 genera. 2. Clasis, 2 genera. 3. Scutum, 2 genera. 4. Placenta, 3 genera.
SECT. III. consists of 3 classes, viz. 1. Arachnoides, 1 genus. 2. Cor marinum, 2 genera. 3. Ovum marinum, 2 genera.
PART VI. Tubulus marinus is composed of 11 genera.
In the systems of Conchology which we have now exhibited, the characters are taken from the shells. In the three following, the marks of discrimination are derived from the animal as well as from the shell. The first by M. Adanson was published in 1757.
This system consists of 3 classes, viz. 1. Limaçons. 2. Les conques. 3. Les conques multivalves.
CLASS I. Limaçons. SECT. I. Limaçons univalves. SECT. II. Limaçons operculés.
SECT. I. Famille. 1. Les limaçons univalves qui n'ont ni yeux ni cornes. Gen. 1. La gondole, cymbium. Famille 2. Les limaçons univalves qui ont deux cornes, et les yeux placés à leur racine et sur leur côté interne. Gen. 2. Le bulin, bulinus. Gen. 3. Le coret, coretus. Gen. 4. Le pietin, pedipes. Famille 3. Les limaçons univalves qui ont quatre cornes, dont les deux extérieures portent les yeux sur leur sommet. Gen. 5. Le limaçon, cochlea. Gen. 6. L'ormier, halotis. Famille 4. Les limaçons univalves qui ont deux cornes, et les yeux placés à leurs racines, et sur le côté externe, ou par derrière. Gen. 7. Le lepas, lepas. Gen. 8. L'yet yetus. Gen. 9. La vis, cerebra. Famille 5. Les limaçons univalves qui ont deux cornes et les yeux posés un peu au-dessus de leur racine, et sur leur côté externe. Gen. 10. La porcellaine, porcellana. Gen. 11. Le puelage, cypræa. Gen. 12. Le mantelet, peribolus.
SECT. 2. Famille 1. Limaçons operculés qui ont deux cornes, avec un renflement, et qui portent les yeux ordinairement au-dessus de leur racine, et à leur côté externe. Gen. 1. Le rouleau, strombus. Gen. 2. La pourpre, purpura. Gen. 3. Le buccin, buccinum. Gen. 4. Le cerite, ceribium. Famille 2. Limaçons operculés, qui ont deux cornes sans renflement, et les yeux placés à leur racine, et sur leur côté externe. Gen. 5. Le vermet, vermetus. Gen. 6. La toupie, trochus. Gen. 7. La natic, natica. Famille 3. Les limaçons operculés, qui ont quatre cornes, dont les deux extérieures portent les yeux sur leur sommet. Gen. 8. Le fabot, turbo. Gen. 9. La nerite, nerita.
CLASS II. Les conques. SECT. I. Les conques bivalves. Famille 1. Les conques bivalves, qui ont les deux lobes du manteau séparés, dans tout leur contour. Gen. 1. L'huître, ostreum. Famille 2. Les conques bivalves dont les deux lobes du manteau forment trois ouvertures sans aucun tuyau. Gen. 2. Le jataron, jataronus. Gen. 3. Le jambonneau, perna. Famille 3. Les conques bivalves dont les deux lobes du manteau forment trois ouvertures dont deux prennent la figure d'un tuyau assez long. Gen. 4. La came, chama. Gen. 5. La telline, tellina. Gen. 6. Le pectoncle, pectunculus. Gen. 7. Le solen, solen.
CLASS III. Les conques multivalves. Famille 1. Les conques multivalves, dont aucune des pièces de la coquille ne prend la forme d'un tuyau. Gen. 1. La pholade, pholas. Famille 2. Les conques multivalves, dont une des pièces de la coquille prend la forme d'un tuyau qui enveloppe entièrement toutes les autres. Gen. 2. Le taret, teredo.
VIII. The method of Geoffroy, formed on similar principles with the last, was published at Paris in 1767, in a work entitled "A Summary Treatise on the testaceous Animals found in the vicinity of Paris." The following is a view of this method.
SECT. I. Coquilles univalves. Gen. 1. Le limax, cochlea. Quatre tentacules, dont deux plus grands portent des yeux à leur extrémité. Coquille univalve en spirale.
History. Gen. 2. Le baccin, buccinum. Deux tentacules plats en formes d'oreilles. Les yeux placés à la base des tentacules du côté intérieur. Coquille univalve en spirale et conique.
Gen. 3. Planorbe, planorbis. Deux tentacules filiformes. Les yeux placés à la base des tentacules du côté intérieur. Coquille univalve en spirale, et ordinairement aplatie.
Gen. 4. La nerite, nerita. Deux tentacules. Les yeux placés à la base des tentacules du côté extérieur. Opércule à la coquille. Coquille univalve en spirale et presque conique.
Gen. 5. Ancile, ancylus. Deux tentacules. Les yeux placés à la base des tentacules du côté intérieur. Coquille univalve concave et unie.
Gen. 1. La côme, chama. Deux siphons simples et allongés. Charnière de la coquille dentelle. Coquille arrondie.
Gen. 2. La moule, mytilus. Deux siphons courts et franchés. Charnière de la coquille membraneuse et sans dents. Coquille allongée.
15
Of Muller. IX. The system of Muller first published in 1773, and afterwards extended in a different work which appeared in 1776, arranges testaceous animals into three families. The following is a view of this arrangement taken from the latter work on the zoology of Denmark and Norway.
Sect. I. Testacea univalvis, testa pervia.
Gen. 1. Echinus. Testa crustacea, ano verticali, tentaculis simplicibus.
Gen. 2. Spatagus. Testa crustacea, ano infero, tentaculis penicillatis.
Gen. 3. Dentalium. Testa calcarea, testa rudi, tentaculis nullis.
Sect. II. Testacea univalvis, testa patula.
Gen. 4. Alera. Apertura effusa, tentaculis nullis.
Gen. 5. Argonauta. Apertura profunda, tentaculis binis.
Gen. 6. Bulla. Apertura repanda, tentaculis binis fetaceis, colliculo extrinsecus oculatis.
Gen. 7. Buccinum. Apertura ovata, tentaculis binis triangularibus, angulo intrinseco oculatis.
Gen. 8. Garyebium. Apertura ovata, tentaculis binis truncatis conspicuis, angulo intrinseco oculatis.
Gen. 9. Vertigo. Apertura subquadrata, tentaculis binis sublinearibus, apice oculatis.
Gen. 10. Turbo. Apertura orbiculari, tentaculis binis fetaceis, conspicuis, angulo extrinseco oculatis.
Gen. 11. Helix. Apertura lunari, tentaculis quatuor linearibus, apice oculatis.
Gen. 12. Planorbis. Apertura semilunari, tentaculis binis fetaceis, angulo intrinseco oculatis.
Gen. 13. Ancylus. Apertura totali tentaculis binis truncatis, occultis, angulo extrinseco oculatis.
Gen. 14. Patella. Apertura totali, tentaculis binis fetaceis, occulto angulo, extrinseco oculatis.
Gen. 15. Haliotis. Apertura repanda, poris pertusa.
Sect. III. Testacea univalvis, testa operculata.
Gen. 16. Tritonum. Libera, apertura canaliculata, tentaculis duobus linearibus, angulo extrinseco oculatis.
Gen. 17. Trochus. Libera, apertura sub-tetragona, tentaculis duobus fetaceis, colliculo extrinseco oculatis.
Gen. 18. Nerita. Libera, apertura lunari, tentaculis duobus fetaceis, angulo extrinseco oculatis.
Gen. 19. Valvata. Libera, apertura circinnata, tentaculis duobus fetaceis, angulo postico oculatis.
Gen. 20. Serpula. Adnata, apertura orbiculari, tentaculis pinnatis.
Sect. I. Testacea bivalvis cardine dentata.
Gen. 1. Mya. Testa altera extremitate hiant; cardine dente crasso solitario.
Gen. 2. Solen. Testa utraque extremitate hiant; cardine dente reflexo, siepe gemino.
Gen. 3. Tellina. Siphone duplici murico; cardine dentibus utrinque tribus alternis.
Gen. 4. Cardium. Siphone duplici, cirrato, pedequo falciformi; cardine dentibus mediis alternis, remotis penetrantibus.
Gen. 5. Venus. Siphone duplici, cirrato, pedequo laminaformi; cardine dentibus tribus approximatis, lateralibus divergentibus.
Gen. 6. Mactra. Cardine dente medio complicato, adjacente foveola.
Gen. 7. Donax. Cardine dentibus duobus, lateralique solitario.
Gen. 8. Area. Cardine dentibus numerosis, alternis, penetrantibus.
Gen. 9. Terebratula. Branchiis circinnatis; cardine dentibus alterius uncinatis, valvula superiore deorsum perforata.
Gen. 10. Anomia. Branchiis simplicibus; valvula inferiore perforata.
Gen. 11. Ostrea. Branchiis simplicibus, pede sullo; cardines fossula cava.
Gen. 12. Pecten. Branchiis cirratis, pede juxta auriculam cardine fossula ovata, byssum emittens.
Gen. 13. Mytilus. Siphone duplici brevi; fossula lineari, byssum emittens.
Gen. 1. Gibton. Valvulae dorsales, tentacula nulla.
Gen. 2. Lepas. Valvulae erectae, tentacula bipartita.
Gen. 3. Pholas. Valvulae ad cardinem minores.
X. To this account of the different methods of arranging shells we shall only add the system proposed by Da Costa in his Elements of Conchology. In this system the author adopts the usual general division into Univalves, Bivalves, and Multivalves.
I. UNIVALVES are distributed into 16 families which are divided into four orders.
Order I. Simple; consists of four families. 1. Patella. 2. Haliotis. 3. Vermiculi. 4. Dentalia. Order II. includes only one family. 5. Polythalamia. Order III. Revolved. Fam. 6. Turbinata involuta. Order IV. Turbinated
Animals which inhabit shells. binated. Fam. 7. Cymbium. Fam. 8. Auris cochlea. 9. Cyndri. Fam. 10. Voluta. Fam. 11. Globosa. Fam. 12. Cassides. Fam. 13. Trochi. Fam. 14. Cochlea. Fam. 15. Buccina. Fam. 16. Murex.
II. BIVALVES composed of 3 orders.
Order I. With unequal valves, and shut close. Fam. 1. Pecken. Fam. 2. Spondylus. Fam. 3. Ostrea. Fam. 4. Anomia. Ord. II. With equal valves,
and shut close, is divided into three sections. Sect. 1. Mult. Articulate. Fam. 5. Peclinoidea. Fam. 6. Peclunculi. Fam. 7. Area. Sect. 2. Articulate. Fam. 8. Peclunculus. Fam. 9. Tellina. Fam. 10. Placenta. Sect. 3. Inarticulate. Fam. 11. Margaritifera. Fam. 12. Musculus. Ord. III. With valves that never shut close. Fam. 13. Chama, Gapers.
III. MULTIVALVES contains one order. Fam. 14. Pholas. Fam. 15. Anatifere. Fam. 16. Balani.
CHAP. II. OF THE ANIMALS WHICH INHABIT SHELLS.
BEFORE we proceed to the classification of shells, we shall here give a short description of the animals which inhabit them. Of these, however, a minute and accurate anatomical description is not to be expected; for little more is known of the structure of these animals than what has been given by naturalists concerning their external characters.
Some of the animals, which inhabit shells, are also found in the mollusca state; that is, without any testaceous covering. Such, for instance, is the limax, or snail.
The animals which have been found inhabiting shells, are the following; viz. Doris, Triton, Ascidia, Tethys, Limax, Spio, Amphitrite, Terebella, Nereis.
Doris.—The body is creeping, oblong, and flat beneath; the mouth is placed below, on the forepart; vent behind on the back, and surrounded by a fringe. Feelers two or four, situated on the upper part of the body in front, and retractile within their proper receptacles.
The animal which inhabits the chiton belongs to this genus.
Triton.—The body is oblong, and the mouth is furnished with an involute spiral proboscis: tentacula or arms 12, six on each side, divided nearly to the base. The hind ones cheliferous.
The triton inhabits different species of lepas.
Ascidia. The body is fixed, roundish, and apparently issuing from a sheath; apertures two, generally placed near the upper end, one beneath the other. The animals are found in the sea, and adhere by their base to rocks, shells, and other submarine substances: they are more or less gelatinous. The only powers of motion which they possess seem to be that of contracting and dilating themselves alternately; by which means they are enabled to throw out the water which they take in with considerable force.
This animal inhabits the pholas, solen, some species of the mya, mactra, and other bivalves.
Tethys.—The body is detached, rather oblong, fleshy, without peduncles: the mouth is furnished with a terminal cylindrical proboscis, under an expanded membrane or lip: apertures two, on the left side of the neck.
The tethys inhabits a great proportion of bivalve
shells, as many species of tellina, cardium, mactra, venus, ostrea, and others.
Limax.—The body is oblong, creeping, with a fleshy kind of shield above, and a longitudinal flat disc beneath: aperture placed on the right side within the shield: feelers 4, situated above the mouth, with an eye at the tip of each of the larger ones.
The animals belonging to this genus inhabit the turbinated univalve shells; but it appears that all the animals which inhabit these shells do not exactly correspond with the above generic characters.
Spio.—The body projecting from a tube, jointed and furnished with dorsal fibres; peduncles or feet rough with bristles, and placed towards the back; feelers 2; long, simple; eyes 2; long.
This animal inhabits some species of fabella.
Amphitrite.—Body projecting from a tube, and annulate; peduncles or feet small, numerous, with lateral fasciculi, and branchiae; feelers 2, approximate, feathered; no eyes.
The amphitrite inhabits some species of fabella and serpula.
Terebella.—Body oblong, creeping, naked, furnished with lateral fasciculi, or tufts, and branchiae; mouth placed before, furnished with lips, without teeth, and protruding a clavated proboscis; feelers numerous, ciliated, capillary, and placed round the mouth.
This animal is an inhabitant of many species of dentalium, serpula and fabella.
Nereis.—Body long, creeping, with numerous lateral peduncles or feet on each side; feelers simple, rarely none; eyes 2 or 4, rarely none. According to some naturalists, the nereis inhabits some species of fabella.
Spio.—Body fleshy, receiving the breast in a sheath, with a tubular aperture at its base; arms 8, beset with numerous warts or suckers, and in most species 2 pedunculated tentacula; head short; eyes large; mouth resembling a parrot's beak.
The animal which inhabits the argonauta is considered by naturalists as belonging to this genus.
Glio.—Body oblong, naked, generally sheathed and furnished with two dilated membranaceous arms or wing-like processes; tentacula 3, besides 2 in the mouth.
According to some naturalists, it is an animal belonging to this genus, which inhabits the argonauta.
AS it will tend to facilitate our progress in the study of Conchology, clearly to understand the terms which are employed in describing shells, and the names by which the different parts have been distinguished by naturalists; we shall here give a few definitions of the principal terms. And that these definitions may be easily consulted, we shall observe the same order as in the classification which is to be adopted. They may be conveniently arranged, therefore, into the three divisions of multivalves, bivalves, and univalves.
MULTIVALVE shells are composed of more than two pieces.
Articulated (testæ articulatæ), when the different pieces of which the shell is composed are so strongly united that they seem to form one shell.
Equivalue shells (testæ equivalves), when the valves of the two sides have the same form, size, and position.
A shell is said to adhere (testæ adherens), when it is attached to solid bodies by some of the pieces of which it is composed: It is said to be loose (testæ libera), when it is not attached by any point.
Pedunculated (testæ pedunculata), when all the pieces of which it is composed, are supported by a tendinous peduncle which is fixed to solid bodies.
Tubular (testæ tubulosa), when the greatest part of the shell is formed of a cylindrical tube.
Base of the shell (basis testæ), that part on which it is supported.
Ligament (ligamentum), is a membranous or tendinous substance which connects the valves together, and sometimes lines the cavity of the shells. Of this there are several varieties.
— scaly (ligamentum squamatum), when the surface is covered with small granular scales.
— prickly (ligamentum aculeatum), when the surface is furnished with small rough points.
— smooth (ligamentum leve), when the surface has neither points, scales, nor tubercles.
— punctated (ligamentum punctatum), when the surface is marked with small cavities.
Lid (operculum), is the name given to four small triangular valves articulated in the form of a cross, which shut up the superior orifice of some species of multivalve shells.
Peduncle (pedunculus) is the tendinous substance which supports some of the multivalve shells. It is flexible while the animal is alive, and is smooth or scaly.
Radii (radii); these are impressions on the external surface of some shells; they are of a conical form, having the vertex turned towards the base of the shell. They are only distinctly seen in adult shells.
— filiform (radii filiformes) are long and narrow.
— smooth (radii leves.) —
— striated (radii transversim striati.) —
Valves (valvulæ) are the different pieces of which multivalve shells are composed.
A BIVALVE shell is said to adhere (testæ adherens), when it is fixed by any part of one of its valves to a solid body.
It is said to have ears (testæ aurita), when it forms at its base, one or two compressed angles.
Gaping (testæ hians), when the valves do not shut close.
Bearded (testæ barbata), covered externally with an epidermis composed of strong hair or bristles.
Compressed (testæ compressa), when the valves are flat, forming a small cavity.
Heart-shaped (testæ cordata), having the form of a heart; (subcordata) approaching to that form.
Toothless (edentula), without teeth at the hinge.
Equilateral (testæ equilatera) when the anterior and posterior part of the shell is equal in form and figure.
Equivalue (equivalvis), when the two valves are similar in form and convexity.
Irregular (testæ irregularis), when the form varies in the individuals of the species.
Lenticular (lenticularis), when the valves are round, and little elevated in the middle, and diminish gradually in thickness towards the edges.
Linear (testæ linearis), when the length considerably exceeds the breadth, but without a cylindrical form.
Tongue-shaped (linguæformis), flat and oblong, having the two extremities round and obtuse.
Boat-shaped (navicularis) resembling the figure of a boat.
Peclinated (peclinata), when the valves being furnished with longitudinal ribs, have on their anterior surface ribs nearly transverse which form by their union with the first acute angles.
Radiated (radiata), when it is marked on the external surface with rays, ribs, or elevated striae, which proceed from the extremity of the summits, and terminate in the circumference of the valves.
Beaked (rostrata), when one of its surfaces, either anterior or posterior, being contracted and elongated, terminates in form of a beak.
Base (basis). The situation in which Linnæus has described and considered bivalve shells, consists in placing the beaks of the shell turned downwards, in such a way that the ligament of the valves may be seen, so that the base of the shell is the region of its beaks.
Margin of the shell (margo testæ) signifies the whole circumference of the shell, parallel to the edge of the valves. It is divided into anterior, posterior, and superior.
— anterior (margo anterior), when the shell is placed on the beak of the valves, commences at the side of the ligament, on the fore-part of the beaks,
mits, and extends to one third of the whole circumference of the valves,
Margin posterior (margo posterior), extends to one-third of the circumference from the beaks of the valves behind.
— superior (margo superior), includes the upper part of the circumference of the valves comprehended between the superior extremity of the anterior margin, and the superior extremity of the posterior margin. Hence the whole circumference of the shell is divided into 3 equal parts.
Margins of the valves (margines valvularum), signify the whole interior circumference of the valves, including about the breadth of a line of the outer edge. They are divided into
— farrowed (margines canaliculati), having on some part of the anterior circumference, a small gutter parallel to it.
— notched (margines crenulati), furnished interiorly with rounded notches.
— toothed (margines dentati), provided with pointed teeth.
— folded (margines plicati), furnished with folds which reciprocally correspond with those of the opposite valve.
— simple (margines simplices) having neither folds, teeth, nor notches.
— striated (margines striati), having longitudinal striae.
Hinge. The hinge of a shell is the most solid and thickest part of the circumference of the valves, constituting their base. It is almost always furnished with teeth of different proportions, which serve to fix the valves together. The hinge is
— compressed (cardo depressus), formed of one compressed tooth.
— lateral (cardo lateralis), when it is placed at one of the sides of the shell.
— oblong (cardo oblongus), when it occupies the whole base of the shell.
— reflected (cardo reflexus), when its edges are folded back externally towards the convexity of the valves.
— terminal (cardo terminalis), situated at the inferior extremity of the shell.
— truncated (cardo truncatus), when the base of the shell terminates transversely and suddenly, and the teeth of the hinge are fixed in this part.
Teeth (dentes), are solid protuberances, commonly pointed, with which the hinge of shells is usually furnished, and which are destined to fix the two valves together. They are divided into
— alternate (dentes alternati) when they are placed in a line parallel to the edges of the hinge; and when the teeth of one valve are received into the interstices of the teeth of the other valve.
— articulated (dens insertus), when it is received in a corresponding cavity at the opposite valve.
— forked (dens duplicatus seu bifidus), having the point divided into two.
— cardinal (dens primarius seu cardinalis), is the tooth which is placed immediately opposite.
— compressed (dens depressus), which is very much flattened.
Teeth erect (dens erectus), when the valve is laid on the convex side, the tooth rises perpendicularly.
— longitudinal (dens longitudinalis), when it extends like a rib on the base of the valves.
The disk (discus), signifies the convex centre of the valves, which is usually situated between the belly of the shell and its limb.
Limb (limbus) is the circumference of the valves from the disk to their edges.
Belly of the shell (testæ umbo), is the most inflated part of the valves.
It is vaulted (umbo fornicatus) when in the interior of the valves it exhibits a cavity separated from the hinge by a vertical membrane.
Nates signify two protuberances of a conical figure, somewhat spiral, which accompany the external base of most bivalve shells. They are
— flattened (nates depressæ), when the surface is sensibly compressed.
— approximate (nates approximatae) meeting together, when the shell is shut.
— horned (nates corniformes), when the angles being considerable, and their direction waved or spiral, they resemble a horn.
— bent (nates incurvatae), when the curvature of the one is directed towards that of the other.
— separated (nates distantes), when they are separated from each other, at least the distance of a line.
— distant (nates remotissimæ), when the interval is very great.
— reflected (nates recurvæ), when the curvature is directed towards the posterior surface of the shell.
— wrinkled (nates rugosæ), when the surface is marked with unequal lines.
— spiral (nates spirales), when the curvature exhibits more than one circumvolution.
Valva, is situated at the lower part of the anterior margin of the valves. It is divided into
— hollowed (excisa, seu canaliculata), when it is marked with a groove during its whole length.
— distinct (distincta), marked by a perceptible difference of colour.
— lettered (scripta seu literata), when the surface is marked with lines resembling written characters.
— inflected (inflexa), when the edge of the lips is bent towards the inner surface of the valves.
Anus, signifies an impression usually hollow, placed at the lower part of the posterior surface. It is divided into
— bordered (marginatus), when it is circumscribed by a distinct elevation.
— heart-shaped (cordatus), exhibiting the form of a heart.
— toothed (dentatus), furnished with teeth or notches.
— lanceolated (lanceolatus), when the length is greater than the breadth, and the extremities are pointed.
— open (patulus seu hians), forming by the separation of its edges, a considerable opening, which penetrates into the interior of the shell.
— oval (ovatus), of an elliptical figure.
Valves, of bivalve shells, are divided into right and left, equal and unequal, equilateral and inequilateral, superior and inferior.
— right valve (dextra), is distinguished from the left, by placing the shell on its base, having the cardinal ligament before, and the anus behind. In this position the right valve of the shell corresponds to the left of the observer, and the left valve (sinistra) to the right of the observer.
— equal (equales), when the right valve corresponds with the left in form, size, and other external characters.
— superior (valvula superior). In an irregular shell, such as the oyster, one of the valves is attached to solid bodies; the other in this case is superior. This valve is sometimes called by Linnaeus, the lid (operculum): in some species it is flat and small, and in others more convex than the inferior valve.
— keel-shaped (valvulae carinatae), when one part of their convexity presents a sharp edge.
— chambered (concameratae), when they exhibit in their cavity testaceous plates, detached and raised.
— spinous (spinose), when the whole surface is furnished with spines.
— banded (fasciatæ), exhibiting large coloured transverse stripes or bands.
— lamellated (lamellosæ), when the surface is furnished with plates more or less separated.
— radiated (radiatæ), exhibiting divergent or coloured rays.
— sinuated (lacunosæ), when one of the valves has a sensible depression at the middle of its margin, and a corresponding elevation of the opposite valve.
— striated (striatæ) when the surface is marked with striae.
— transverse, when the striae are parallel to the margin of the valves.
— longitudinal, when they run from the base to the circumference.
Muscular impressions (impressiones), are marks on the interior surface of the valves, where the muscles of the animal are attached.
— solitary (solitarie), when the inner surface of each valve has only one.
— double (duPLICATE), two on the inner surface of each valve.
— triple or ternate (ternatæ), three in each valve.
Ligament (ligamentum), is a horny substance, of little flexibility, which unites the two valves near their base, and which in almost all bivalve shells is placed at the lower part of their anterior surface. It is divided into.
— gaping (bians), when its upper extremity is divided into two.
— double (duplex), when under the external ligament there appears a second, in a particular hollow of the hinge, which does not appear externally.
— internal (internal), when it unites the valves without appearing externally.
— profound (retractum seu intractum) when it is so deep in the suture as scarcely to be seen when the valves are shut.
— truncated (truncatum) when shorter than its suture.
Furrows (salci), are those impressions or interstices between the ribs or rays on the surface of the valves.
— square (quadrati), when the bottom is flat.
— lamellated (lamellosi), when the bottom is marked with small transverse scales.
— punctated (excavato punctati), when the whole surface is marked with small cavities or dots.
3. Explanation of Terms applied to Univalve Shells.
The base, (basis) is the most elevated part of the Univalve shell, opposite to the spire. It is divided into
— notched (emarginata), when it is accompanied with a deep notch.
— tubular (tubulosa seu cordata), when it is formed by a tube.
— simple or entire (simplex aut integra), without notch or tube.
Summit (vertex) signifies the top of some patellæ, and from its position is central, marginal, or submarginal.
The shell (testa) is divided with regard to its position into superior and inferior.
The anterior part (pars antica), is that which forms the spire of the shell; and it is also the superior part.
The form of shells is
— bordered (marginata), when the two sides of the opening are broader and thicker than the rest of the diameter.
— chambered (polythalamia), when it is internally divided by different partitions parallel to the opening.
— convoluted (convoluta), when the spires turn round a lengthened cone, nearly vertical to each other.
— rooted (radicata), when it is attached to a solid body by a ligament proceeding from its base.
— interrupted (interrupta), when the successive additions to the shell are marked with distinct rings.
— umbilicated (umbilicata), when the axis round which the sphere turns, being empty, forms a cavity at the base of the shell, whose diameter is at least a sixth part of that of the shell.
— imperforated (imperforata seu exumbilicata), when its inferior axis has neither hole nor umbilicus.
— oval or elliptic (ovales), the longitudinal diameter exceeding the transverse, and the two extremities equal and a little contracted.
— egg-shaped (ovata), the longitudinal diameter exceeding the transverse, and the extremities terminated by the segment of a circle.
— beaked (rostrata), when the two extremities, sometimes tubular, form a projection in form of a beak.
— imbricated (imbricata), when the surface is covered with parallel scales, so arranged as to cover each other.
— turbinated (turbinata), when the belly of the shell is large in proportion to the spires, which seem to proceed from its center.
Opening or mouth (apertura), is that part of the cavity of the shell which is visible. It is
- _____ angular (angulata), when its circumference has several angles.
- _____ gaping (deliscens), when one of the extremities is wider than the other.
- _____ bimarginated (bimarginata), when the right lip forms a double margin.
- _____ compressed (coarctata), when it is distinctly flattened.
- _____ femicircular (semiorbiculata), when it forms half a circle.
- _____ linear (linearis), when it is narrow, and the length considerably exceeds the breadth.
- _____ longitudinal (longitudinalis), when the length is greater than the breadth, and the greatest dimension is parallel to the axis of the shell.
- _____ orbicular (orbicularis), forming an entire circle.
- _____ striated (striata), when the cavity is marked with striae, parallel to the direction of the convolutions.
- _____ transverse (transversa), when the breadth is greater than the length.
Pillar (columella), is that part of the shell situated within the opening, near its axis, round which the spires turn. It is brought into view by dividing the shell its whole length. It is
- _____ flattened (plana), when the surface is flat and smooth.
- _____ caudated (caudata), when it is lengthened beyond the base of the shell.
- _____ folded (plicata), marked with transverse and distinct folds.
- _____ spiral (spiralis), proceeding from the base, and forming a small, twisted elongation.
- _____ truncated (truncata), cut transversely at the base.
Convolutions (anfractus), are the turnings of the spire round the pillar, from the opening to the base of the shell. They are
- _____ bifid (bifidi), when each is divided into two equal parts by a furrow or spiral line.
- _____ grooved (canaliculati), when the superior edge is marked with a groove.
- _____ keel-shaped (carinati), when the outer turn of the shell is marked with an angle more or less acute.
- _____ crowned (coronati), when the upper surface is bordered at a little distance from the futures, with a single row of tubercles or spinous scales.
- _____ dextral (dextris), turning from the left to the right.
- _____ sinistral (sinistris), turning from the right to the left.
- _____ lettered (scripti), marked with characters.
- _____ spinous (spinosi), having short spines on the surface.
- _____ entire (simplices), without furrows or tubercles.
- _____ banded (fasciati), when the surface is marked with broad coloured stripes.
- _____ lamellated (lamellati), the surface marked with longitudinal or transverse excrescences, and laminated like membranes.
_____ lineated (lineati), marked with coloured lines.
_____ radiated (spinolo-radiati), having the circumference bordered with straight spines, separating and divergent.
_____ separated (disjuncti), having an interval between each convolution.
_____ furrowed (fulcati), having the surface marked with furrows, which are always broader than striae.
_____ decussated (decussati), when the striae cross each other at right angles.
Spire (spira), signifies all the convolutions taken together. It is
- _____ pointed (acuta), when the convolutions joined together form an acute angle.
- _____ flattened (depressa), forming a flat surface.
- _____ convex (convexa), when it is rounded, and the point of the base has little elevation.
- _____ convex (convexo-acuta), rounded at the outer edge, but elevated into an acute angle.
- _____ convex and elevated (convexo-exerta), rounded at the outer edge, and elevated without forming an acute angle.
- _____ convex and pointed (convexo-mucronata), obtuse and almost rounded at the outer edge, and terminated at the center with a pointed elevation.
- _____ crowned (coronata), when the outer edges of each convolution are accompanied with a row of spines or tubercles.
- _____ capitate (capitata), the convolutions united, forming a swelling resembling a head.
- _____ obtuse (obtusa), the convolutions united, forming an obtuse angle.
- _____ plano-concave (plano-concava), the convolutions forming no elevation, but are slightly grooved.
- _____ pyramidal (pyramidata), of a conical form.
Sutures (futurae), signify the place of junction of the different convolutions, forming a spiral line. They are
- _____ grooved (canaliculatae), when they are so deep as to form a small canal.
- _____ notched (crenulatæ), when the points of contact are marked with notches.
- _____ double (duplicateæ), accompanied with two striae, which run parallel.
- _____ effaced (obsoletæ), when the place of junction is not perceptible.
Siphon (sipho), is a small canal situated in the internal part of the shell of the nautili, which penetrates into the divisions of which it is composed. It is
- _____ central (centralis), when it is situated in the middle of the divisions.
- _____ lateral (lateralis), situated at one side.
- _____ oblique (obliquus), cutting the axis of the divisions obliquely.
Veins (varices) are elevations or ribs, running in the direction of the length of the shell, formed by the junction of the different additions which the shell has received. They cut the convolutions of the spire transversely. They are
- _____ continued (continuatae), proceeding from the base of the spire to the convolution at the opening, without interruption.
- _____ spinous (spinoseæ), furnished with strong spines.
- _____ interrupted (decussatae), not corresponding with the different convolutions.
SHELLS are divided by Linnaeus into multivalve, bivalve, and univalve. In the following classification the same arrangement will be adopted; and we shall first exhibit in one view the characters of each genus, in the original language of Linnaeus, with a translation opposite, for the sake of the English reader; so that the genus of any shell may be easily determined. In
describing the species, we shall observe the utmost brevity, giving such characters only as are necessary to afford precise marks of distinction. In arranging the species under each genus, the British species will be distinguished with an asterisk; so that, with the advantage of a general classification, this will answer the purpose of a British conchology.
1. CHITON. Animal doris. Testæ plures, secundum longitudinem sibi oppositæ dorso incumbentes.
2. LEPAS. Animal triton. Testa basi affixa multivalvis: valvis inæqualibus erectis.
3. PHOLAS. Animal ascidia. Testa bivalvis divaricata, cum minoribus accessoriis difformibus: cardo recurvatus cartilagine connexus.
1. C. Animal inhabiting the shell a doris. Shell consisting of several segments or valves disposed down the back.
2. L. Animal a triton. Shell affixed at the base, and consisting of many unequal erect valves.
3. P. Animal an ascidia. Shell bivalve, divaricate, differently shaped; accessory valves: hinges bent back, united by a cartilage: beneath the hinge internally, is an incurved tooth.
4. MYA. Animal ascidia. Testa bivalvis hians, ut plurimum, altera extremitate: cardo dente (plerisque uno) solido, crasso, patulo, vacuo; nec inserto testæ oppositæ.
5. SOLEA. Animal ascidia. Testa bivalvis oblonga, utroque latere hians. Cardo dens subulatus reflexus, siepe duplex, non insertus testæ oppositæ, margo lateralis magis obsoletus.
6. TELLINA. Animal tethys. Testa bivalvis, anterus hinc ad alterum latus flexa. Cardinis dentes ut plurimum tres: laterales plani alterius testæ.
7. CARDIUM. Animal tethys. Testa bivalvis subæquilatera, æqualvis plerumque convexa, longitudinaliter costata, striata aut sulcata, margine dentata. Cardo dentibus mediis binis alternatis: altero ut plurimum incurvo; lateralibus remotis insertis.
8. MACTRA. Animal tethys. Testa bivalvis, inæquilatera, æqualvis. Cardo dente medio complicato cum adjecta foveola, lateralibus remotis insertis.
9. DONAX. Animal tethys. Testa bivalvis, margine siepe crenulato antico obtusissimo. Cardo dentibus duobus; marginalique solitario (rarius duplici, triplici, aut nullo) subremoto sub ano.
10. VENUS. Animal tethys. Testa bivalvis; labiis margine antico incumbentibus. Cardo dentibus tribus, omnibus approximatis, lateralibus apice divergentibus.
4. M. Animal an ascidia. Shell bivalve, generally gaping at one end. Hinge with broad, thick, strong teeth (seldom more than one), and not inserted into the opposite valve.
5. S. Animal an ascidia. Shell bivalve, oblong, open at both ends. Hinge with a subulate, reflected tooth, often double, and not inserted in the opposite valve, the lateral margin more effaced.
6. T. Animal a tethys. Shell bivalve, generally sloping on one side, in the fore part of one valve a convex, of the other a concave fold. Hinge usually with three teeth: the lateral ones in one shell being smooth.
7. C. Animal a tethys. Shell bivalve, nearly equilateral, æqualvalve, generally convex, longitudinally ribbed, striated or grooved, with a toothed margin. Hinge with two teeth near the beak, and a larger remote lateral one on each side, each locking into the opposite.
8. M. Animal a tethys. Shell bivalve, of unequal sides, and æqualvalve. Middle tooth of the hinge complicated, with a small hollow on each side, lateral ones remote and inserted into each other.
9. D. Animal a tethys. Shell bivalve, generally with a notched margin: the frontal margin very obtuse. Hinge with two teeth, and a single marginal one placed behind (rarely double, triple, or none).
10. V. Animal a tethys. Shell bivalve; the frontal margin flattened with incumbent lips. Hinge with three teeth, all approximate; the lateral ones divergent at the tip.
11. SPONDYLUS. Animal tethys. Testa inequalivalvis rigida. Cardo dentibus duobus recurvis, cum foveola intermedia.
12. CHAMA. Animal tethys. Testa bivalvis crassior, cardo callo gibbo, oblique inserto fossulae oblique.
13. ARCA. Animal tethys? Testa bivalvis sequivalvis. Cardo dentibus numerosis, acutis alternis insertis.
14. OSTREA. Animal tethys. Testa bivalvis (plurimis inequalivalvis subaurita). Cardo edentulus, fossula cava, ovata, sulcisque (in plurimis) lateralibus transversis.
15. ANOMIA. Animal corpus ligula emarginata ciliata: ciliis valvae superiori affixis: brachiis duobus lineariibus corpore longioribus conniventibus porrectis, valvae alternis utrinque ciliatis: ciliis affixis valvae utrinque: testa inequalivalvis, valva altera planiuscula, altera basi magis gibba: parum altera basi saepe perforata. Cardo cicatricula lineari prominente introrsum dente laterali; valvae vero planioris in ipso margine. Radii duo offei pro basi animalis.
16. MYTILUS. Animal ascidia? Testa bivalvis, rudis, sepius affixa bysso, ut plurimum, crassiori. Cardo in plurimis edentulus, distinctus, paucis exceptis, linea subulata, excavata longitudinali.
17. PINNA. Animal limax. Testa sub-bivalvis fragilis, erecta hians, emittens barbam byssinam. Cardo edentulus, coalitis in unam valvis.
11. S. Animal a tethys. Shell hard, solid, with unequal valves. Hinge with two recurved teeth, separated by a small cavity.
12. C. Animal a tethys. Shell bivalve, rather coarse. Hinge with a callous protuberance, obliquely inserted in an oblique hollow.
13. A. Animal a tethys? Shell bivalve equivalve. Hinge with numerous sharp teeth, alternately inserted between each other.
14. O. Animal a tethys. Shell bivalve, generally with unequal valves, and slightly eared. Hinge without teeth, but furnished with an ovate cavity, and in most with lateral, transverse furrows.
15. A. Animal an emarginate, ciliated, strap-shaped body, with bristles attached to the upper valve; arms two, linear, longer than the body, projecting and approaching together, alternate on the valve, and ciliated on each side, with bristles affixed to each valve. Shell inequalivalve, one of the valves flattish, the other protuberant at the base: one of the valves often perforated near the base. Hinge with a linear prominent cicatrix, and a lateral tooth placed within; but on the very margin of the flat valve there are two bony rays for the base of the animal.
16. M. Animal an ascidia? Shell bivalve, rough, generally affixed by a byssus or beard of silky filaments. Hinge mostly without teeth, and in most cases with a subulate, hollow, longitudinal line.
17. P. Animal a limax. Shell bivalve, brittle, gaping at one end, and having a byssus or beard. Hinge without teeth, the valves being united into one.
III. UNIVALVE SHELLS.
18. ARGONAUTA. Animal sepia aut clio. Testa univalvis, spiralis, involuta, membranacea, unilocularis.
19. NAUTILUS. Animal? Testa univalvis, isthmis perforatis concamerata, polythalamia.
20. CONUS. Animal limax. Testa univalvis convoluta, turbinata; apertura effusa, longitudinalis, linearis, edentula, basi integra; columella levis.
21. CYPRÆA. Animal limax. Testa univalvis, involuta, sub-ovata, obtusa, levis. Apertura utrinque effusa, linearis utrinque dentata longitudinalis.
22. BULLA. Animal limax. Testa univalvis convoluta, inermis. Apertura sub-coarctata, oblonga, longitudinalis, basi integerrima. Columella obliqua, levis.
23. VOLUTA. Animal limax. Testa unilocularis spiralis. Apertura ecaudata, sub-effusa. Columella plicata: labio umbilicove (ut plurimum) nullo.
24. BUCCINUM. Animal limax. Testa univalvis, spiralis, gibbosa. Apertura ovata desinens in canaliculum (retusam lacunam) dextrum, cauda retusa. Labium interius explanatum.
25. STROMBUS. Animal limax. Testa univalvis, spiralis, latere ampliata. Apertura labro saepius dilatato, desinens in canalem sinistrum.
26. MUREX. Animal limax. Testa univalvis, spiralis, exasperata futuris membranaceis. Apertura defi-
18. A. Animal a sepia or clio. Shell univalve, spiral, involute, membranaceous, one cell.
19. N. Animal? Shell univalve, divided into several chambers communicating with each other.
20. C. Animal a limax. Shell univalve, convolute, turbinata; aperture effuse, longitudinal, linear, without teeth; entire at the base. Pillar smooth.
21. C. Animal a slug. Shell univalve, involute, subovate, smooth, obtuse. Aperture effuse at each end, linear, extending the whole length of the shell, and toothed on each side.
22. B. Animal a limax. Shell univalve, convolute, without teeth. Aperture a little narrowed, oblong, longitudinal, quite entire at the base. Pillar oblique and smooth.
23. V. Animal a limax. Shell one cell, spiral. Aperture without a beak, and somewhat effuse. Pillar twisted or plaited: generally without lips or perforation.
24. B. Animal a limax. Shell univalve, spiral, gibbous. Aperture ovate, ending in a short canal, leaning to the right, with a retuse beak. Internal or pillar lip expanded.
25. S. Animal a limax. Shell univalve, spiral, enlarged at the side. Aperture dilated with the lip expanding, and ending in a groove towards the left.
26. M. Animal a limax. Shell univalve, spiral, rough, with membranaceous sutures. Aperture oval,