AND DESCRIPTIONS OF NEW SPECIES. 83 



Unio Elegans. Plate IX. fisr. 13. 



O' 



Testa subtriangulari, suhaquilaterali, per umbones complanata ; latere antico 

 valvularum crassiori ; epidermide luteo-viridi ; radiis numerosis ex lineis angulatis 

 compositis ; natibus complanatis incurvisque ; dentibus cardinalibus elatis grandi- 

 busque, lateralibus subrectis ; margarita alba et iridescente, raro rosed. 



Shell subtriangular, nearly equilateral, flattened over the umbones; valves thick 

 before, thinner behind; epidermis yellowish green with numerous rays formed of 

 zigzag lines ; beaks incurved and flattened ; cardinal teeth large and elevated ; 

 lateral teeth nearly straight; nacre pearly white and iridescent, rarely rose co- 

 loured. 



Hab. Ohio river, T. G. Lea. 



My Cabinet. 

 Cabinet of Prof. Vanuxem. 

 Cabinet of H. C. Carey. 

 Cabinet of P. H. Nicklin. 

 Cabinet of the Academy of Natural Sciences of Philadelphia. 

 Cabinet of the American Philosophical Society. 

 Diam. 1, Length 1-5, Breadth 1-9 inches. 



Shell subtriangular, nearly equilateral, acutely angular behind ; flat- 

 tened over the umbones ; umbonial slope carinate ; posterior slope much 

 flattened ; substance of the shell thick before, thinner behind ; beaks 

 flattened, incurved, nearly touching ; ligament short and thick ; epider- 

 mis yellowish green, with numerous rays, formed of zigzag lines, di- 

 verging from the beaks to all parts of the margin; basal margin 

 slightly emarginate ; cardinal tooth large, elevated, and widely cleft in 

 the left valve, and emerging from a pit in the right valve ; lateral teeth 

 nearly straight ; anterior and posterior cicatrices both distinct ; dorsal 

 cicatrices situated in the centre of the cavity of the beaks ; cavity of 

 the beaks rounded ; nacre pearly white, (rarely pink) and iridescent. 



Remarks. — This interesting and beautiful species has been consi- 

 dered as a variety of the U. donaciformis (Nob.). I had but a single 



