POMUS. 



Shell dextral, 

 Fig. 3. 



POMUS, Humphrey. 



Siphon elongate. Operculum horny, dextral 

 globose, widely umbilicated, last whirl very- 

 large, ventricose ; spire short ; aperture en- 

 tire, oblong, large, expanded, peritrerae 

 simple, always thin, sometimes subreflexed. 



The genus Pomus differs from Anipullaria 

 in the absence of the thickened ledge within 

 the peritreme for the operculum, which lat- 

 ter, moreover, is entirely horny. The spe- 

 cies inhabit the lakes and rivers of warm 

 countries, more especially those of South America and the West 

 Indies. In the dry season they bury themselves deeply in the 

 mud, where they remain in a state of torpidity, and, on account 

 of their possessing a pulmonary cavity in addition to the gills, 

 they are enabled sometimes to survive a considerable period after 

 having been removed from the water. The South American 

 Indians term them "Idol Shells," and are said to hold them in 

 great veneration. 



Pomtis deprensa. 



Pomus depressa, Say. — Shell ventricose, subglobular, obsoletely 

 banded with obscure green ; whirls four, 



slightly wrinkled ; body whirl more pro- Fig- 4. 



minent above, somewhat flattened towards 

 the suture, of a pale olivaceous color, 

 which is almost concealed by numerous 

 unequal, longitudinal and transverse 

 greenish and brownish lines ; spire very 

 much depressed ; aperture suboval, within 

 somewhat glancous, on the margin exhi- 

 biting the bands distinctly ; labrum sim- 

 ple, as much rounded above as below ; 

 umbilicus small, nearly closed. Greatest 

 width one inch and nine-twentieths, total 



length one inch and a half; length of the Ampullaria depressa. 



aperture one and one-fifth of an inch nearly. 



Inhabits East Florida. 



