COLIMACEA. 



115 



has divided the genus Helix, consisting of Bulinus decollatus, 

 fig. 279, and similar species. See HeHx. 



COCHLICOPA. Fer. A sub-genus of Helix, partly correspond- 

 ing with Polyphemus of De Montfort, and consisting of species 

 of Achatina, which have the outer lip undulated. 



COCHLITOMA. Eer. A sub-genus of Helix, corresponding 

 with the genus Achatina, Auct. not including those with undu- 

 lated outer lips. 



COCHLODESMA. Couthoy. Boston Journal. Forbes and 

 Hanley, British Mollusca. Fam. Myaria. Thin, inaequivalve ; 

 muscular impressions connected by a deeply siuuated palleal 

 impression ; hinge with spoon-shaped process in each valve, with 

 a cartilage ; external Kgament slight ; beaks fissured. Distin- 

 guished from Thracia by the character of the hinge. Ex. C. 

 prgeternis. PI. xxvii. fig. 573. 



COCHLODINA. Fer. A sub-genus of Helix, including the 

 genus Clausilia, Auct. 



COCHLODONTA. Fer. A sub-genus of Helix, containing 

 Pupa IJva, Auct. &c. 



COCHLOGENA. Fer. A sub-genus of Helix, containing pupi- 

 form shells, such as Azeca tridens, fig. 290. 



COCHLOHTDEA. Fer. A sub-genus of Helix, composed of 



■ the genus Succinea, Auct. 



COCHLOSTYLA. Fer. A sub-genus of Helix, composed of the 

 genus Bulinus, Auct. 



COLIMACEA. Lam. This Family, of the order Trachelipoda, 

 Lam. includes all land shells, which might with propriety be 

 divided into three sections, the first of which contain the follow- 

 ing well known genera : — 



1. SucciifEA. Oval, transparent, oblique ; animal amphibious. 



Fig. 265, 266. 



2. Helix. The type of which is the common snail shell. 



The separation of Carocolla, on account of the angulated 

 whorls, or that of Geotrochus, on account of the turbinated 

 shape, cannot be well maintained. Fig. 264, 267, 268, 

 273 to 276, 278 to 281, 294. 



I 2 



