UNIO LINEOLATUS. 



SPECIFIC CHARACTER. 



Subtriangular, disk and umbo much depressed; beaks 

 simple, prominent. 



SYNONYMS. 



U. lineolata; U. depressa, (young,) Raf. Ann. gen. des 

 Sc. Phys., vol. V. Mr. Poulson's translation, p. 35. 



U. sEcuRis, Lea. Trans. Amer. Phil. Soc, new series, 

 vol. iii. p. 437, pi. xi. fig. 17. 



DESCRIPTION. 



Shell subtriangular, surface brownish-yellow, with nu- 

 merous slender green radii and broader distant radii, 

 frequently composed of series of angular dark spots, with 

 pale intervening spaces; disk and umbo much compressed; 

 beaks simple, prominent, in the young acute at the apex; 

 anterior side subcuneiform; anterior margin regularly 

 but slightly arquated, very much flattened, forming a 

 right angle with the disks; posterior side short, obtusely 

 rounded at tip; within white; cardinal teeth very large, 

 profoundly sulcated and striated; lateral teeth inclining 

 to be double in each valve. 



OBSERVATION. 



This species is common in the Ohio, Alabama, and 

 Black Warrior rivers. 

 PI. 68. 



