CATALOGUE FAMILY VXIOXLD.E. 



GENUS UNIO, 



Outer gillunitcd to tfic mantle as far as its extremity: inner (fill' not united 

 to the foot. 



Shell cquivalve, inequilateral, variable in shape, covered with an olivace- 

 ous epidremis; beaks usually eroded (1), Hinge with primary teeth, and 

 with elongated laterals; ligament external, more or less elongated. Pallia f 

 impression simple; muscular scars conspicuous. (H. and A. Adams.) 



f Unio abacus, Ilakleman, 



(Figured?) 

 ''Tennessee. No further information is at present attainable. 



\ Unio aberti, Conrad. 



( Figured ?) 

 Described from the ;< Verdigris river, Arkansas.'' 



f Unio aciUMis, Lea. 



(Observations on the Genus T'nio, Vol. XIII, PI. VIII, Fi.jj. 24.) 



Holston and Clinch rivers, east Tennessee. This species groups with Uui<f 

 clavus, Lam. 



* Unio a}sopns, Green. 



(Figured '/> 



Ohio to central Iowa and south to the Tennessee river in north Alabama. 

 Holston river, east Tennessee, at Knoxville, is the most eastern locality re- 

 ported. This is one of the few species the animals of which tire rubiginose, or 

 salmon colored. 



f Unio aflinis, Lea, 



(Trans. Am. Phil. Sot 1 .. -<1 Series. Vol. X, P;. XIX, Fiir. 26.) 



Described from the lied river, at Alexandria, Louisiana. This is the only 

 information recorded concerning the distribution of the species. 



(1) An eroded beak is certainly not a generic- character, and it is not to be presumed 

 the author .so considered it. It i- usually quite impractical to observe the character 

 of the beaks, since they are eroded and this is probably the meaning intended. Com- 

 pie: ing this portion of the generic diagnosis it would stand "licahs m.dtdate concentri- 

 c-ally or rugosely apiculate, sometime* smooth." 



CATALOGUE 10. 



