342 JYew species of Fresh Water Shells. 



nacre waxen yellow, except on the margin, which is pearly white and 

 highly iridescent. 



Cyclas staminea. pi. 1. fig. 5. 



Shell oval, ventricose, inequilateral ; with numerous regular prom- 

 inent concentric lines ; beaks slightly prominent ; anterior and poste- 

 rior ends nearly equally rounded; cardinal teeth none; lateral teeth 

 distinct. 



Inhabits small streams in South Alabama. Figure of the natural 

 size. Cabinet of the Academy of Natural Sciences of Philadelphia. 



Shell oval, regularly convex ; inequilateral ; anterior and posterior 

 ends similarly rounded ; umbo inflated ; beaks a litde prominent, 

 apex obtusely rounded; epidermis yellowish, with darker stains; 

 lateral teeth rather prominent; nacre bluish white; cavity capacious. 



Melania olivula. pi. 1. Fig. 13. 



Shell oblong or narrow-elliptical, smooth and entire ; spine con- 

 ical ; volutions five ; suture impressed ; aperture somewhat elliptical, 

 longitudinal ; about half the length of the shell, color green olive ; 

 with strongly marked brown revolving bands ; about 4 on the body 

 whorl. 



Far. A. Much more elevated, with a truncated or eroded apex ; 

 the whorl flattened, and the spine less conical. 



Observations. Inhabits the Alabama river, adhering to the soft 

 calcareous banks, which it perforates in such a manner that they re- 

 semble honey comb, or wood pierced by Teredo navalis. 



Melania prasinata. PI. 1. Fig. 14. 



Shell subulate, slightly turrited ; whorls 7 or 8, flattened ; aperture 

 elliptical, a little oblique ; about one third of the length of the shell; 

 body whorl sub-angulated at base ; epidermis green olive. 



Far. A. with broad revolving costee, those on the body whorl cre- 

 nulated. 



Inhabits Alabama river, adhering to limestone rocks. Cabinet of 

 ihe Academy of Natural Sciences of Philadelphia. 



Anculosa picta. Fig. 15. 



Shell sub-oval, shoulder obtusely rounded ; aperture obovate, 

 large ; columella callous above ; epidermis olive, with numerous 

 quadrangular small spots disposed in revolving lines, strongly mark- 

 ed in the aperture. 



