[5] 



Art. I. — Description of fifty-two species of Unioiiidce. 



By Isaac Lea. 

 Unio globatus. pi. 1, fig. 1. 



Testa Isevi, globosa, valde inflata, valde inffiquilaterali ; valvulis crassis, antice crassioribus ; natibus 

 valde inflatis, parura elevatis ; epiderraide tenebroso-fusca ; dentibus cardinalibus per crassis et 

 valde corrugatis ; lateralibus curtis, crassis, parum curvatis corrugatisque ; margarlta argentea 

 et iridescente. 



Shell smooth, globose, very much inflated, very inequilateral ; valves thick, 

 thicker before ; beaks very much inflated, somewhat raised ; epidermis dark brown ; 

 cardinal teeth very thick and very much corrugate ; lateral teeth short, thick, 

 somewhat curved and corrugate ; nacre silver white and iridescent. 

 Proc. Acad. Nat. Sci., 1871, p. 191. 



Hab. — Holston River, Dr. Edgar. Etowah Eiver, Geo,, Th. Bland. 



My cabinet. 

 Diam. 1-2, Length 1-6, Breadth 1-8 inch. 



Shell smooth, globose, very much inflated on the umbones, very inequilateral, 

 rounded before and behind ; substance of the shell very thick, thicker before ; 

 beaks somewhat raised and much inflated; ligament short, thick, and dark brown; 

 epidermis dark brown, with close marks of growth ; umbonial slope rounded; 

 posterior slope cordate and with indistinct lines from the beaks to the margin ; 

 cardinal teeth very thick, very much sulcate and roughened, disposed to be treble 

 in the right valve ; lateral teeth short, thick and corrugated, and somewhat curved ; 

 anterior cicatrices distinct, rather small, and deeply impressed ; posterior cicatrices 

 distinct, rather small and well impressed ; dorsal cicatrices placed on the under 

 side of the cardinal teeth ; cavity of the shell rather shallow and wide ; cavity of 

 the beaks rather deep and obtusely angular; nacre silver white and iridescent. 



RemavTcs. — Many years since the late Dr. Edgar sent me two specimens from 

 East Tennessee. I hesitated to consider it a distinct species until I received a 

 third specimen from my friend Mr. Bland, who obtained it from a different habitat. 

 It is a remarkable spherical species, and may be confounded with suhrotundus on 

 one side, and subglohatus herein described on the other. It is a much smaller 

 species than the first, and more rounded than the latter. It need not be con- 



2 



