CUVIER. 



523 



D. shell turbinate, the aper- 

 ture channelled . 



ACEPHALES 



A. A. naked 



Murex, 

 Strombus, 

 Cassis, 

 Buccinum, 



Ascidia, 



B. A. conchiferous and apod-\ o Vi 

 ous, the shell inequivalve . \ pi ' 



Lima, 



Perna, 

 Avicula, 



C. A. conchiferous and ivith 

 a foot, the valves equal, J ^ 

 and the lobes of the mantle ' 

 open in front .... 



Voluta, 

 Oliva, 

 Cypraea, 

 Conus. 



Bipliores, 

 Anomia, 

 Pecten. 



Tellina, 



Cardium, 



Mactra, 



Venus, 



Chama, 



D. A. conchiferous and with\ 



Pinna, 



Anodonta, Area 

 Unio, 



en, 



Sol 

 Mya, 



Pholas, 

 Teredo. 



.Terebratula, Orbicula. 



.Anatifa, Balanus. 



afoot, the valves equal, the 



shell gaping at both ends, 



the lobes of the mantle close 



in front 



E. A. conchiferous and apod- 



ous, furnished with two 



fleshy ciliated spiral ten- i Lingula. 



taenia 



E. A. testaceous, furnished. 



with a number of jointed 



and ciliated tentacula ar- 

 ranged in pairs 

 There are, you perceive, three primary sections of equal 

 value, and their characteristic names are for the first time in- 

 troduced into science. In preceding systems the Cephalo- 

 pods were considered to be constituents of the order of soft 

 worms, while the Nautilus and Argonauta were members of 

 the order Testacea. The division of the Gasteropods into 

 two subsections from the absence or presence of a shell was 

 not a happy one ; and the unnatural result was to remove 

 the Limax far away from its near relative the Helix. The 

 claims of the Thalides and Lernaea to a place in this order 

 were subsequently proved to be unfounded. The arrange- 

 ment of the testaceous Gasteropods is borrowed partly from 

 Linnaeus and partly from Adanson ; and Poli professedly 

 supplied the characters on which Cuvier distributed the Bi- 

 valves into their families. He was more original and acute 

 when he embodied with them the naked Acephales, although 

 it is probable that he may have found the hint of their 



