522 



LETTER XXVII. 



THE HISTORY OF SYSTEMS OF CONCHOLOGY FROM THE 

 PUBLICATION OF CUVIER's SYSTEM TO ITS COMPLETION. 



I have, in my last letter, sketched rather than written the 

 history of Conchology from its first origin to the end of the 

 last century ; but I must trace its future progress with a 

 more tedious pen, and travel, moreover, with a guide through 

 its cross and reticulated byepaths. For the names which 

 claim a place in this history are many, and being often those 

 of contemporaneous men, I might find a difficulty in assign- 

 ing each his place, — the works of many of them being placed 

 far beyond my reach by the expensive manner in which they 

 have been published ; nor does my library furnish the various 

 editions even of those which have been most influential. I 

 shall, therefore, assume Deshayes for my guide ; * who, so 

 far as my means enable me to judge, is both an honest and 

 a learned one. 



It was in 1798 that Cuvier published this his first arrange- 

 ment : 



MOLLUSCA. 



Genera. 



r, f Sepia, Argonauta, 



Cephalopodes r\ \ AT +-1 



I Octopus, JN autilus. 



/Limax, Phyllidia, 



Tethys, Scyllaea, 



Gasteropodes. G. naked . A Aplysia, Thalides, 



Doris, Lernaea. 



^Tritonia, 



G. testaceous 



A. shell multivalve . . Chiton. 



B. shell univalve, not spiral Patella. 



Haliotis, Bulimus, 



. shell turbinate, the aper- 

 ture entire .... 



Nerita, Bulla, 

 Planorbis, Turbo, 

 Helix, Trochus. 



* Traite Ele'mentaire de Conchyliologie, avec l'application de cctte Science 

 a la Ge'ognosie. Par G. P. Deshayes, 2 vols. 8vo. 1839. This work, which 

 1 cannot too highly commend, is indispensably necessary to the Conchologist. 

 It is not yet completed. 



