VALVATA HUMERALIS, Say. 



SYNONYMS AND REFERENCES. 



V. HUMERALIS, SAY. Disseminator, Aug. 12, 1829, p. 244. 



j.t j 

 DESCRIPTION. 



SHELL " subglobose, depressed: spire convex, 

 not prominent: whirls three and a half; with 

 the shoulder depressed, plane: wrinkled across, 

 or rather with slightly raised lines: aperture 

 appressed to the penultimate whirl, but not in- 

 terrupted by it: umbilicus rather large. 



"Greatest breadth less than one-fifth of an 

 inch. 



"Inhabits Mexico. 



OBSERVATIONS. 



"Differs from V. sincera of the Northwest 

 Territory in being more depressed and in having 

 a shoulder or plane surface near the suture. 

 The umbilicus is larger than that of V. pisci- 

 nalis, Mull., and the spire more depressed; the 

 species is also destitute of the depressed 

 shoulder." Say. 



