68 NEW UNIONIDvE OF THE UNITED STATES. 



cardinal teeth rather large, striate, and somewhat compressed ; lateral teeth long, 

 thick, corrugate and somewhat curved ; nacre silver white and iridescent. 

 Proo. Acad. Nat. Sci. 1861, p. 60. 



Eab. — Etowah River; Rev. G. White. Oostenaula River, Georgia ; Bishop Elliott; 

 and Cahawba River, Alabama ; E. R. Showalter, M. D. 



My cabinet and cabinets of Mr. White, Bishop Elliott, and Dr. Showalter: 

 Diam. 1, Length 1*3, Breadth 2 - l inches. 



Shell smooth, very oblique, swollen and truncate before, compressed and obtusely 

 angular behind ; substance of the shell very thick, thicker before ; beaks swollen, 

 raised, incurved and terminal ; ligament rather long, somewhat thick and dark brown ; 

 epidermis yellowish chestnut brown, obscurely rayed, transversely banded along the 

 lines of growth, which though numerous, are not very close, shining above and striate 

 below ; umbonial slope very slightly raised, flattish ; posterior slope slightly raised, 

 elongate heart-shaped, with a well impressed line from the beak to the posterior mar- 

 gin ; cardinal teeth rather large, striate and somewhat compressed ; lateral teeth long, 

 thick, corrugate, slightly curved and nearly horizontal ; anterior cicatrices distinct, 

 small and deeply impressed; posterior cicatrices distinct, rather small and well im- 

 pressed ; dorsal cicatrices placed above the centre of the cavity of the beaks ; cavity 

 of the shell shallow and wide ; cavity of the beaks very shallow and rounded ; nacre 

 silver white and iridescent. 



Remarks. — Some specimens of this shell were sent to me some years since by 

 Bishop Elliott and the Rev. G. White. Recently, I have received from Dr. Showal- 

 ter several, including some young ones. These have enabled me to come to the con- 

 clusion, that they did not form simply a variety of decisus, as I thought probable. It 

 is higher in the beaks than that species, and is not so much spread out, nor has it so 

 pale yellow an epidermis. It is very near to crebrivittatus, herein described, and may 

 easily be confounded with that shell, having many of its characters, but the more 

 distant marks of growth will at once distinguish it. It has very much the same 

 character of teeth, the cardinal and lateral ones being nearly parallel. The young are 

 well banded, and have well defined rays over most of the disk. There were none 

 with perfect heads. 



Umo ASPERATUS. PI. 7, fig. 218. 



Testa valde tuberculata, subrotunda, inflata, antice" et postice rotunda, subsequilaterali ; valvulis crassis, 

 antice crassioribus; natibus valde prominentibus ; epideimide rufo-lutea, eradiata ; dentibus eardi- 

 nalibus peicrassis, obtuso-conieis, corrugatis ; lateralibus brevissiruis, valde obliquis rectisque ; margarita 

 argentea et irideseente. 



Shell very much tuberculate, nearly round, inflated, round behind and before : 

 nearly equilateral ; valves thick, thicker before ; beaks very prominent ; epidermis 



