8 NEW UNIONIDiE, MELANID^, ETC., 



Unio pertenuis pi. 2, fig. 4. 



Testa Ifevi, obovata, inflata, sublenticular!, inasquilaterali, postice obtuse biangulari, antice rotundata ; 



valvulis pertenuibus, autice parum crassioribus ; uatibus subprominentibus, ad apices rugoso-undulatis ; 



epidermide virente et radiis indutis ; dentibus cardinalibus parvissimis, compressis, obliquis; lateralibus 



acicularis rectisque ; margarita ossruleo-alba et valde iridescente. 

 Shell smooth, obovate, inflated, sublenticular, inequilateral, obtusely biangular be- 

 hind, rounded before ; valves very thin, somewhat thicker before ; beaks somewhat 

 prominent, rugosely undulate at the tips ; epidermis greenish and covered with rays ; 

 cardinal teeth very small, compressed, oblique ; lateral teeth acicular and straight ; 

 nacre bluish white and very iridescent. 



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

 Ed). — Neuse Kiver, near Raleigh, North Carolina, E. Emmons, M. D. 

 My cabinet and cabinet of Dr. Emmons. 

 Diam. "5, Length '8, Breadth 1'4 inches. 



Shell smooth, obovate, inflated, sublenticular, inequilateral, obtusely biangular be- 

 hind, rounded before; substance of the shell very thin, slightly thicker before; beaks 

 somewhat prominent, rugosely undulate at the tips ; ligament very thin and pale 

 brown ; epidermis greenish, with rays over the whole disk, and with very distant marks 

 of growth ; umbonial slope swollen and rounded : posterior slope rather wide, usually 

 covered with green rays, and raised into a high carina nearly amounting to a wing ; 

 cardinal teeth very small, compressed and oblique; lateral teeth acicular, double in 

 the left and single in the right valve ; anterior cicatrices distinct, rather large and 

 slightly impressed ; posterior cicatrices confluent and scarcely visible ; dorsal cicatrices 

 placed immediately over the cavity of the beaks ; cavity of the shell rather deep and 

 rounded; cavity of the beaks rather shallow and subangular; nacre bluish white and 

 very iridescent. 



RemarJcs. — This is a small, thin species, which, in outline, is very near to Tappani- 

 anus (nobis) . It also has nearly the same color and rays on the epidermis, but it is 

 not so high in the carina. In the lateral teeth they differ entirely, Tappanianus 

 having a single one in both valves, while pertenuis is single in the right and double in 

 the left valve. It has also some resemblance to Prattii and Soladoensis, (nobis), but 

 cannot be confounded with either of them. The tips of the beaks have on each valve 

 three or four double rugose undulations. 



Unio Charlottensis. PI. 2, fig. 5. 



Testa laevi, elliptica, subcompressa, insequilaterali, ad latere parum planulata ; valvulis subtenuibus, antice 

 crassioribus ; natibus vix prominentibus ; epidermide tenebroso-fusca, eradiata ; dentibus cardinalibus 

 parvissimis, compressis, valde obliquis ; lateralibus parviusculis, lamellatis et acuminatis; margarita 

 albida et iridescente. 



