47 



UNIO PEROVATUS. 



Plate 11— Fig. 3. 



DESCRIPTION. 



Shell ovate, rather ventricose, valves thick on the 

 anterior side, thinner posteriorly; anterior margin 

 regularly rounded; basal margin rounded; posterior 

 extremity subangulated; beaks rather elevated, ap- 

 proximate, undvilated; epidermis olive, wrinkled on 

 the margin; cardinal teeth erect and prominent, not 

 very thick; nacre white. 



Uiiio perovatus, nob. Silliman's Journal, vol. xxv. 

 p. 338, pi. i. fig. 3. 



OBSERVATIONS. 



The regular ovate form of the shell will distinguish 

 it from most other species; the young shell, however, 

 is broader behind, approaching to an oval figure, 

 and is ornamented with green rays on an olive yellow 

 ground. It inhabits small streams in Greene county, 

 Alabama. 



ANODONTA TERES. 

 Plate YIL—Mg. 2. 



DESCRIPTION. 



Shell narrow-elliptical, inflated; posterior side pro- 



