MALACOLOGY. 



MALACOLOGY. 



Family ffautiiidtt. 



Diteorbit. Siderolita. Polyttomella. rortidalit. Nummulitet. 

 tfautilta. 

 (") Shell mul tUooular, with chamber* pinked (decoupe's at the edges). 



Family Ammcmilidce. 

 Ammonitti. Orbulittt. Ammonoctrtu. Turrilitet. SaevlittM. 



2nd Division. Monothalamous Cephalopoda. 

 Shell unllocular, entirely external, and enveloping the animal 

 Argonauta. 



3rd Division. Sepiary Cephalopoda, 

 No shell, either internal or external A solid free cretaceous 



or horny body, contained in the interior of the greater part of the 



animal. 



Oetopiu. Loliyopiit. Lollgo. Sepia. 



Order 5. Heteropoda. 



Body free, elongated, swimming horizontally. Head distinct ; two 

 eyes. No arms surrounding the head. No feet under the belly 

 or under the throat for creeping. One or more fins, without any 

 regular order, and not disposed by pairs. 



Carinaria. Ptcrotrachea. Phyliirvr. 



Such was Lamarck's arrangement, as be finally left it, after various 

 modifications in the course of his publications, from the commence- 

 ment of them to the second edition of his ' Animaux sans Vertebres.' 

 During that interval many authors had presented their views to the 

 public, and we proceed to notice some of them. 



In 1800 M. d'Audebard de Fdrussac (the father) produced a system 

 of Conchology based on the consideration of the animal and its shell 

 He introduced some observations on the complete or incomplete state 

 of what he calls the 'spiral cone* of the shell, and the point of attach- 

 ment of the foot, under the neck or under the belly of the Gastropods. 

 lli< views were limited to the Terrestrial and Fluviatile Molluscs, or 

 Musculites, as he calls them, and subdivides them into orders almost 

 as numerous as his genera, among which we find Hdicolimax, forming 

 the passage between the lAmacrs and the Helica. 



The work of M. Bosc, in the supplements to Buffon (Dei, 1802), 

 may be considered as rather of a retrograde character, for it still 

 clung to the system of Linnaeus as amended by Bruguiere ; and, not- 

 withstanding the progress already made, we find him adhering to the 

 terms Molluscous Worms and Testaceous Worms, as designating the 

 Naked and Testaceous Mollutca. His divisions were nearly those of 

 Bruguiere, though he adopted the new subdivisions which Cuvier and 

 Lamarck had established, and appears to have been conscious of the 

 value of those innovations. Bosc was an observer, and had studied 

 many of the Mollutca in a living state. He established many new 

 facts and some new genera. 



In 1803 appeared the 'Prodromus' of the work of Draparnand, which 

 was not published till after his death in 1808, on the Terrestrial and 

 Fluviatile Atolluica of France. This work is conceived and executed 

 in a philosophical spirit, and with rational views of a natural system 

 of classification. He abandoned the arbitrary method of Linnaeus, and 

 returned to the principle proposed by Rcaumer (1711) in his ' Memoir 

 on the Progressive Motions of Shells,' making his classification that of 

 Cuvier. 



The 'Natural History of Molluscs,' for Sonnini's edition of Buffon, 

 was hardly commenced by Denys de Montfort, and almost entirely 

 executed by M. I)e Roissy. The classification is carried out on the 

 principles of Cuvier, but the author differs from Cuvier on some points, 

 as, for instance, in thinking that the section of the Anodons ought not 

 immediately to follow that of the Oysters, and that the aperture which 

 ('iivirr regarded as anterior in Siphora was really posterior an 

 opinion in which he is supported by Messrs. Bosc, Pdron, Do Blainville, 

 Chamiiuo, and Kuhl. In this work the analogy of the Polythalamous 

 or < 'numbered Shells is pointed out M. De Roissy appears to have 

 perceived the passage from the Univalve to the Bivalve Molluscs by 

 means of the Patella, and he seems to have been the first who placed 

 AtpergiUum near to Fittulana, a position which it still holds. 



M. Dumenl, in 1806, published, in his 'Zoologie Analytique,' a 

 clanification of M oilmen nearly similar to that of Cuvier. M. Dumcnl 

 divides the MoUutca into five orders : Cephalopoda, Pteropoda, Gattero- 

 poda, Acrphala, and Braehiopoda. The principal novelties in this 

 publication were a division of the Qaiteropoda, according to their 

 organx of respiration, into three families Dtrnobranchiata, Siphono- 

 brtuichiata, and Adelobranchiata which correspond nearly to the 

 three divisions established on the structure of the shell ; and a separa- 

 tion of the Brachiopnda as a distinct order. 



In 1808 Denys de Montfort published his 'Univalves Cloisonnees,' 

 and in 1810 the second volume of his ' Conchyliologie Systematiqtie,' 

 containing the 'Univalves non Cloisonnees. His genera are very 

 minvrou*, and not many of them are retained at present by zoologists, 

 though they arc for the most part neatly defined. His method is only 

 carried out with regard to the Univalves ; but his primary division 

 rests upon the number of valves, and is separated into Univalves, 

 Multivalves, and Bivalves, as in the systems of the older oonchologist*. 

 He differs however in restricting the term Multivalves to shells made 



up of several united pieces, without any solution of continuity; 

 whilst he applies the term Dissivalves to shells made up of many 

 pieces, but not coherent nor adherent to each other, as Teredo, Fitlu- 

 (ono, Salantu, Ac. 



Oken, in 1810, read to the Society of Qottingen a paper upon the 

 knowledge of Mollutca apart from their shells and upon a natural 

 classification established upon this basis; and carried out this principle 

 in his ' Manual of Nat Hist,' published at Jena in 1816. Our limits 

 will not allow us to do more than call the reader's attention to this 

 work, which he will find well worthy of perusal, though it does not 

 contain any new principle of arrangement, and there is somewhat too 

 much of change of name :>.lx>ut his genera, of which there are but few 

 really new. Nor can we do more than hint at the work of M. Rafinesque 

 (Palermo, 1814). About the year 1816 much light was thrown on the 

 Aggregated Mollusca by Lesueur, Desmarest, and above all by the 

 great Savigny, and in 1817 M. De Blainville first made known the 

 principles of his system, which he afterwards carried out to its com- 

 pletion. The systems of Goldfuss and Ranzani appeared in the same 

 year, 1820, the first at Nuremberg and the second at Bologna ; the 

 first may be regarded as a compilation of the labours of those malaco- 

 logists who had embraced the natural system ; and the basis of the 

 second, as far as the Cirrhipeds are concerned, rests on the structure 

 of the shell and its opercnlum without regard to the animal, and, as 

 far as relates to the Acephalous Molluscs, does little more than give 

 new denominations to the four sections of that division. 



M. De Ferussac (the son) divided (1 81 9) the Mollusca into two grand 

 sections, the Cephalous and the Acephalous. 



Cephalous Mollutca. 



These are divided into three classes Cephalopoda, Pteropods, and 

 Gastropods. 



The first class, Cephalopoda, contained the two orders, Decapods 

 and Octopods, as in the arrangement of Dr. Leach. This class in the 

 system of De Fdrnssac embraces all the naked Cephalopoda and all 

 the animals with multilocular shells ; but was subsequently consider- 

 ably modified in a joint-work with M. D'Orbigny. 



The second class, Pteropods, which originally consisted of the 

 families Jlyalttce, Limacince, the Clios, the Pneumoderms, and the 

 Phyllirhoes, also underwent considerable changes in a subsequent and 

 joint-work with M. Rang. 



The third class, Gastropods, are divided into the following orders 

 and suborders: 1, Nudibrauchians (Anthrobranchians and Poly- 

 branchians). 2, Inferobranchians (Phillidians and Semi-Phillidians). 

 3, Tectibranchians. 4, Pulmonians without an operculum (Geophilians, 

 Gehydrophylians, and Hygrophilians). 6, Operculated Pulmonians. 

 6, Peotinibranchians (Pomastomes, Hcmipomastomes, Apomastomes, 

 and Adeloderms). 7, Scutibranchians, Ormiers (Huliotis, &c.), Calyp- 

 tracians, Heteropods. 8, Cyclobranchians (Chismobranchiaus and 

 Polyplaxiphores). 



Acephalous Molluica. 



These are divided into four classes Cirripedes, Brachiopods, Lamel- 

 libranchians, and Tuniciers. 



The first, Cirripedes, is divided into the orders Sessile Cirripedes 

 and Pedunculated Cirripedes. 



The second, Brachiopods, contains the three families Lingulidrr, 

 Terebratulida, and Cranida;. 



The third, Lamellibranchians, comprehends five orders the Ostra- 

 ceans, Mytilaceans, Benetiers(7Vi'<i<idu>and IJippoptu),t\ie Cardiaceans, 

 and the Enfermea (Myidte, Solenidcf, Pholidte, and Tubicolidce). 



The fourth, Tuniciers, consists of the two orders Tethid Ascidians 

 (Tethidcc and the Pyrosomes) and Thalid Ascidians (liiphora, &c.). 



In England Dr. Leach had been active in introducing a natural 

 system, as appears from his published papers, descriptions, and works. 

 He had it in contemplation to publish a general history of English 

 Molluica; but the most distressing of maladies deprived zoology 

 of one of its most zealous cultivators, and the work has never 

 appeared. 



Dr. J. E. Gray published in the ' London Medical Repository' (1821), 

 his system, which divides the Mollutca (taken in the largest sense of 

 the word) into seven clases. 



The first, Antliobrachiophora (Cephalopoda), consists of three orders 

 Anotteophora, Srpitephora, and Kantilophora. 



The second, Oasteropodophora, is divided into three sub-classes 

 Pneumobranchia, Cryptobranchia, and (lymnobranchia. 



The first of these Sub-classes contains two orders Addopnewnona 

 and Phaneropneumona. The second embraces nine orders the 

 Clcnobranchia, which are divided into six sections by the application 

 of a new principle, namely, the form of the operculum : the Troche- 

 lobranchia ; the Monopteurvbranchia ; the Nolobranckia ; the Chitma- 

 tobranchia; the Dicranobranchia ; the Cyclobranchia ; the Poly- 

 placophora; and the l>ij,Uuroljranchia. The third class consists of 

 two orders Pygobranchia and PolybrancMa. 



Dr. Gray's third class, Oatteropterophora, corresponds with the 

 Heteropoda of Lamarck, and is similar to M.'Do Blainville' order 

 Pfucleobranchiata. 



The fourth class, Stomatopterophora, corresponding with the Ptero- 

 poda, contains two orders, Pterobranchia and JJactyliubranchla. 



