Miscellaneous. 301 



more distinct rays, and is proportionally longer ; the cardinal tooth in 

 the left valve is longer and less lobed, and the lateral teeth are 

 straight, without granules, and less oblique than in the preceding 

 species, which is a larger shell. 



U. oratus. Widely elliptical, ventricose, gaping at both ends ; 

 posterior gape wide ; anterior extremity rather acutely rounded ; 

 posterior margin sinuous, extremity subangular ; basal margin form- 

 ing a nearly regular curve ; summits prominent ; umbo and beak 

 eroded ; epidermis ochraceous, polished ; cardinal teeth compressed, 

 oblique ; lateral teeth straight ; within white, much stained with 

 waxen yellow. 3;^. 



Inhabits Flint River, Georgia. 



This shell has the polished epidermis of U. cariosus, but is with- 

 out a ray. It is longer in proportion than that species, with very 

 different cardinal teeth, which are much nearer parallel with the 

 margin above ; the shell also gapes far wider in the only specimen 

 I have seen. 



U. rosaceus. Widel}?^ elliptical, ventricose above ; posterior mar- 

 gin obliquely truncated, slightly sinuous ; extremity subangular or 

 acutely rounded ; epidermis ochraceous and dark brown ; rays indi- 

 stinct, frequently broad, but composed of fasciculi of lines ; surface 

 with fine radiating wrinkles ; within deep rose-purple ; cardinal 

 teeth prominent, oblique, compressed, trifid, or three teeth in the left 

 valve. 3^. 



Inhabits Savannah River. 



Allied to U. oclwaceus, Say, 



U. contrarius. Elliptical, moderately thick ; valves somewhat 

 flattened or plano-convex ; umbo and beak not prominent, much 

 eroded ; umbonial slope acutely rounded ; posterior margin straight 

 above, truncated, direct ; epidermis deep ochraceous, with linear 

 radiating wrinkles, and obscurely rayed about the umbo ; within pale 

 flesh-colour stained with waxen yellow ; cardinal teeth direct, thick, 

 sulcated, not very prominent ; lateral teeth reversed, or the double 

 tooth in the right valve. 3 1-5. 



Inhabits the Ogeechee River. 



U. nucleopsis. Obtusely subovate, slightly oblique, thick, not 

 ventricose ; umbonial slope rounded ; posterior slope with a few 

 obscure plaits ; posterior margin subtruncated ; basal margin slightly 

 tumid near the middle ; epidermis ochraceous, with a series of green 

 spots along the umbonial slope ; posterior slope obsoletely striated ; 

 within bluish white ; cardinal teeth thick, direct, single in the right 

 valve. 1^. 



Inhabits Etowah River. 



U. limatulus. Subelliptical, convex ; posterior side somewhat 

 pointed ; umbonial slope angular ; posterior slope subcarinated in the 

 middle ; posterior margin obliquely truncated ; extremity truncated, 

 direct; basal margin regularly rounded; beaks not prominent, eroded; 

 epidermis highly polished, dark brown and ochraceous, obscurely 



