82 



UNIO BULLATUS. 



Plate XLV. Fig. 2. 



DESCRIPTION. 



Shell elevated, equilateral, inflated, irregularly tu- 

 berculated on the middle and posterior slope; medial 

 tubercles generally large; substance of the shell thick; 

 beaks elevated and granulated at tip; ligament slope 

 descending, short; posterior margin direct, nearly 

 straight; epidermis bright brown, a single broad in- 

 terrupted green ray passes from the apex to the middle 

 of the disk; within white; lateral teeth very short, 

 straight, thick and oblique. 



SYNONYMES. 



U. bullata, Raf. Ann. gen. des Sc. Phys., vol. v. p. 41. Poul- 



son's trans., p. 43. 

 U. verrucosus albus, Hild. Silliman's Journ., vol. xiv. p. 289. 

 U. pustulosus, Lea. Trans. Amer. Phil. Soc, new series, vol. 



iv. p. 76, pi. vii. fig. 7. 

 Cab. A. N. 3., No. 1175. 



OBSERVATIONS. 



Inhabits the Ohio and its tributaries, Alabama and 

 Black Warrior rivers. This common species is 

 easily recognised, and will be found to differ con- 

 stantly from U. prasinus by its more elevated and 

 ventricose form and more numerous tubercles. It 

 wants the furrow of the Mortoni, and is besides dis- 

 tinguished by its green ray and larger tubercles. 

 The white colour of the nacre is remarkably constant, 



