24 NEW UNIONIDiE, MELANID^, ETC., 



Unio mediocris. pi. 7, fig. 22. 



Testa Ifevi, lato-elliptica, subinflata, valde inajquilaterali, postice subbiangulata. antice rotundata; valvulis 

 subtenuibus, antice parum crassioribus ; natibus prominulis ; epidermide luteo-fusoa, valde radiata; 

 dentibus cardinalibus parvis, striatis, crenulatis ; lateralibus longis, lamellatis subrectisque ; margarita 

 albida vel purpurea et valde iridescente. 



Shell smooth, widely elliptical, somewhat inflated, very inequilateral, subbiangular 

 behind, rounded before; valves rather thin, somewhat thicker before; beaks slightly 

 prominent; epidermis yellowish brown, very much rayed; cardinal teeth small, 

 striate, crenulate ; lateral teeth lamellar and nearly straight ; nacre whitish, or purple 



and very iridescent. 



Proc. Acad. Nat. Sci., 1863, p. 191. 



jg-aJ.—Neuse River, Ealeigh, North Carolina, E. Emmons, M. D, 



My cabinet and cabinet of Dr. Emmons. 

 Diam. -7, Length 1-1, Breadth 2-1 inches. 



Shell smooth, widely elhptical, somewhat inflated, very inequilateral, subbiangular 

 behind, rounded before ; substance of the shell rather thin, slightly thicker before ; 

 beaks a little prominent, with a few rather coarse undulations at the tips ; ligament 

 rather small and brown ; epidermis yellowish brown, with green oblique rays on the 

 whole disk, and with rather distant marks of growth ; umbonial slope raised and 

 rounded; posterior slope rather wide and slightly carinate; cardinal teeth small, 

 striate, crenulate, single in the right and double in the left valve ; lateral teeth long, 

 lamellar and nearly straight; anterior cicatrices distinct, rather large and well im- 

 pressed ; posterior cicatrices confluent, large and slightly impressed ; dorsal cicatrices 

 placed slightly above the centre of the cavity of the beaks ; cavity of the shell rather 

 shallow and wide ; cavity of the beaks very shallow and rounded ; nacre white or 

 purple and very iridescent. 



Eemarks. — Only three specimens were received. Two appear to be of full size, the 

 third is quite young. It reminds one of Griffiiliianus, (nobis,) but it is not quite so 

 wide and is not so much compressed. It also differs in the teeth. The tips of the 

 beaks were not perfect enough to ascertain well the character of the undulations. 



Anodonta doliaeis. pi. 8, fig. 23. 



Testa IsBvi, oblonga, valde ventricosa, subaequilaterali, postice obtuse biangulata, antice oblique rotundata ; 

 valvulis crassis, antice parum erassioribus ; natibus prominentibus et valde inflatis; epidermide luteo- 

 virente, valde radiata et micante ; margarita dilute carnea et valde iridescente. 



Shell smooth, oblong, very much inflated, subequilateral, obtusely angular behind, 

 obliquely rounded before ; valves thick, slightly thicker before ; beaks prominent and 

 very much inflated; epidermis yellowish green, very much rayed and shining; nacre 

 pale flesh color and very iridescent. 



Proc. Acad. Nat. Sci., 1863, p. 193. 



