20 

 SPECIES IV. Unio Fasciata (Elliptio Fasciata.) 



Shell elliptical, ventricose, slightly thick ; 

 epidermis slightly rugose, olive coloured, orna- 

 mented with brown rays ; nacre bluish ; cardinal 

 tooth rugose, divaricated ; lamellar tooth carinated. 

 Length f diam. ^ axis of the breadth. 

 Var. 1. nisro-fasciata dark rays. 

 Var. 2. alternata greenish with blackish rays ; 



alternately broader and narrower. 

 Var. 3. cuprea copper coloured, with olive 



rays ; nacre light copper colour. 

 A handsome species, approaching the U. ochra- 

 ceus of SAY ; commonly small ; I have seen some 

 specimens, however, more than three inches 

 broad. In the rivers Ohio, Allegheny, Musk- 

 ingum, Kentucky, Salt, Green, &c. Muscular 

 impressions slight ; fossule deep. 



Note. We should probably refer to this 

 sub-genus the following species of authors, and 

 perhaps some others : 



Unio Caroliniana of Bosc. 



plicata 1 from Lake Erie LESUEUR. 



Var. of U. crassa.* SAY. 

 purptirea.* SAY. Pennsylvania. . 

 aurata, a new species from the Hud- 

 son : it is elliptical, with the poste- 



* U. crassus 17. purpureus. SAY. TRANS. 



