60 CONCHOLOGIA CESTRICA. 



Sub-order LIMNOPHILA. 



INOPERCULATA. 



Operculum wanting. 



Animal mostly fluviatile, sometimes amphibious; 

 tentacles two, flattened, or subcylindrical, simply con- 

 tractile ; eyes sessile, at the base of the tentacles. 



OBS. Some of the animals of this order are con- 

 sidered terrestrial, as they are only found in wet places, 

 within reach of the tides. They serve as the connecting 

 link between the Geophila and Limnophila. 



Family AURICULID^. 



Shell spiral, with a horny epidermis ; aperture elon- 

 gated ; inner lip strongly folded ; outer, frequently 

 dentate. 



Animal with subcylindrical, contractile, tentacles; 

 with the eyes at their inner base; usually frequenting, 

 salt marshes. 



Genus CARYCHIUM, MULLER, 1774. 



Animal of Cari/cJiium exiguium. 



Fig. 113, 



Shell elongated, very thin, transparent ; aperture with 

 one columellar tooth ; peristome expanded, its extremi- 

 ties not approximate ; the right one, with a small 

 columellar fold. 



C. exiguium, SAY. 



Pupa exigua, Say, Jour. Acad. Phila. F. S., II., 1822. 



