54 DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONID^. 



Hab. — Long Creek, Gaston Co., and PfeifFer's Pond, Mecklenburg Co., North 

 Carolina, C. M. Wheatley. 



My cabinet and cabinet of C. M. Wheatley. 

 Diam. -8, Length 1-5, Breadth 3-1 inches. 



Shell smooth, rather wide, compressed, flattened at the sides, very inequilateral, 

 obtusely angular behind, round before ; substance of the shell rather thin, slightly 

 thicker before ; beaks slightly prominent ; ligament long, somewhat thick and 

 light brown; epidermis dark brown, shining, without rays, with rather close marks 

 of growth ; umbonial slope rounded ; posterior slope narrow elliptical, with indis- 

 tinct lines from the tips of the beaks to the margin ; cardinal teeth rather small, 

 somewhat compressed, sulcose and double in both valves ; lateral teeth very long, 

 lamellar and nearly straight ; anterior cicatrices distinct, large and moderately im- 

 pressed; lateral cicatrices confluent, large and slightly impressed; dorsal cicatrices 

 placed over the centre of the cavity of the beaks ; cavity of the shell very shallow 

 and wide ; cavity of the beaks scarcely observable ; nacre white and iridescent. 



Remarks. — Neither of the six specimens before me has beaks perfect enough to 

 exhibit the undulations of the tips. In outline it is near to viridiradiatus (nobis), 

 but it is wider and more flat. It is also in outline near to puUatus (nobis), but is 

 not so thick in the valves, while it is more compressed. 



