DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONID.E. 17 



Unio litus. pi. 5, fig. 13. 



Testa Iffivi, elliptica, subcompressa, insequilaterali, antice rotundata, postice subbiangulata; valvulis 



subtei'mibus, antice crassioribus ; natibus prominulis; epidermide crocea, eradiata; dentibus car- 



dinalibus parvis compressisque ; lateralibus sublongis, subcurvis lamellatisque ; margarita salmo- 



nis colore tincta et elegantissime iridescente. 



Shell smooth, elliptical, somewhat compressed, inequilateral, rounded before, 



subbiangular behind; valves rather thin, thicker before; beaks a little prominent; 



epidermis saffron-yellow, without rays; cardinal teeth small and compressed; late- 



ral teeth rather long, somewhat curved and lamellar; nacre salmon color and 



elegantly iridescent. 



Proc. Acad. Nat. Sci., 1871, p. 189. 



H"a&.— Cahaba River, Shelby Co., Ala., E. R. Schowalter, M.D. • 



My cabinet, and cabinet of E, R. Schowalter, M.D. 

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



Shell smooth, elliptical, somewhat compressed, inequilateral, rounded before and 

 subbiangular behind ; substance of the shell rather thin, thicker before ; beaks a 

 little prominent ; ligament short and light brown ; epidermis saffron-yellow, with- 

 out rays, with rather distant lines of growth ; umbonial slope rounded ; posterior 

 slope elliptical and slightly carinate ; cardinal teeth small, compressed, double in 

 the left and treble in the right valve ; lateral teeth short, oblique, and lamellar ; 

 anterior cicatrices confluent, rather large and well impressed ; posterior cicatrices 

 large, confluent and slightly impressed ; dorsal cicatrices placed above the centre 

 of the cavity of the beaks ; cavity of the shell shallow and wide ; cavity of the 

 beaks rather shallow and obtusely angular; nacre salmon color, deeper on the mar- 

 gin, brilliant, satin like, very iridescent. 



Remarks.— This is a small species, with a beautiful satin-like nacre. There are 

 two specimens before me ; one apparently full grown, the other more than half 

 mature. In color of exterior and general phase it reminds one of striatuhis (nobis), 

 but it differs in outline, that shell being sub triangular, while litus is elliptical. In 

 outline it is very near to Copei (nobis), but altogether different in color of epidermis 

 as well as in the nacre. In both specimens before me the beaks are eroded. 



Unio Cahabensis. PI. 5, fig. 14. 



Testa valde tuberculata, quadrata, compressa, subsequilaterali, antice rotunda, postice truncata ; val- 

 vulis subcrassis, antice crassioribus; natibus subprominentibus ; epideraaide crocea, eradiata; 

 dentibus cardinalibus subgrandis, compressis crenulatisque ; lateralibus curtis, obliquis lamella- 

 tisque ; margarita salmouis colore tincta et elegantissime iridescente. 



5 



