om ae 47 : 
UNIO PEROVATUS. 
Puate Il.—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, undulated; epidermis olive, wrinkled on 
the margin; cardinal teeth erect and prominent, not 
very thick; nacre white. 3 
Unio perovatus, nob. Silliman’s Journal, vol. xxv. 
p. 338, pl. 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. 
Prave VIL=Fig: 2. 
. DESCRIPTION. 
Shell narrow-elliptical, inflated; posterior side pro- 

