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. 
Oxs.—Some of the animals of this order are con- 
sidered ¢errestrial, 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 Carychium exiguium. 
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. 
