44 AMNICOLlDiE. 



Family AMNIGOLIDM. 

 (Amnicola, Hald., Turbidse, p. 4.) 



Genera. 

 A. SJiell smooth. 



Shell elongated, perforate, smootli, 



Bythinella. 



Shell turbinate ; whorls very convex, umbili- 

 Gate ; aperture round ; peristome continu- 

 ous, acute, .... Amnicola. 



Shell elongated, perforate, smooth, very con- 

 vex ; aperture round ; peristome continuous, 

 slightly expanded or reflected. Amphibious. 

 Animal, foot with lateral sinuses, 



POMATIOPSIS. 



Shell heliciniform, thick ; aperture oblique ; 

 umbilicus large, with an angulated margin, 



COCIILIOPA. 



Shell subglobular, thin ; spire short ; aperture 

 large, half-round ; peristome not continuous ; 

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