FRESHWATER AND LAND SHELLS. 23 



Continuation of Mr Lea's Taper. Bead, February 5th, 1836. 



Unio ruMiLus. Plate VII. fig. 17. 



Test& subtriangulari, incequilaterali, postich subbiangulata ; valvulis subtenuibus ; natihus 

 prominulis ; epidermide tenebroso-fusca ; dentibus cardinalibus grandibus; laieralibus brevi- 

 bus reciisque ; margarita alba. 



Shell subtriangular, inequilateral, behind subbiangular ; valves rather thin ; beaks 

 somewhat prominent ; epidermis dark brown ; cardinal teeth large ; lateral teeth short 

 and straight ; nacre white. 



Hab. Black River, North Carolina. 



My Cabinet. 

 Diam. -5, Length -8, Breadth 1-1 inches. 



Shell subtriangular, inequilateral, behind subbiangular, somewhat 

 carinate ; substance of the shell rather thin ; beaks somewhat promi- 

 nent ; ligament short ; epidermis dark brown, and apparently without 

 rays ; cardinal teeth large, and deeply cleft in the left valve ; lateral 

 teeth short and straight ; anterior cicatrices distinct ; posterior cicatri- 

 ces distinct ; dorsal cicatrices situated on the under part of the cardi- 

 nal teeth ; cavity of the shell rather deep ; cavity of the beaks angular ; 

 nacre bluish white. 



Remarks. — A single individual of this species was found by me in 

 1827, in crossing the Black River, on the road to Fayetteville from 

 Smithfield. The publication of it has been delayed, in the hope of 

 other specimens being found. Although it has every appearance of an 

 adult shell, it may be found larger. Nevertheless, I have no doubt 

 but that it is among the smallest of the genus. It approaches in most 

 of its characters the modestus (Fer.), from Brazil, but it is not so thick 

 a shell, and is rather smaller. 



