FRESHWATER AND LAND SHELLS. 105 



angular and shallow ; nacre white, and very iridescent on the posterior 

 portion. 



Remarks. — This species more nearly resembles U. iris (nobis) than 

 any other I am acquainted with. It is, however, a thicker shell, more 

 angular behind, and not quite so transverse. The epidermis is more 

 yellow. I am indebted to the kindness of Dr Jay for the specimen 

 in my cabinet, from which the figure is taken. 



Unio Claibornensis. Plate XXIV. fig. 115. 



Testa ellipticd, subinjlatd, incequilaterali ; valvulis crassis ; natibus subprominentibus ; 

 epidermide luteola, lavi; denlibus cardinalibus parvis ; later alibus longis lamellatisque ; 

 margariia alba el iridescente. 



Shell elliptical, somewhat inflated, inequilateral; valves thick; beaks somewhat pro- 

 minent ; epidermis yellow, smooth ; cardinal teeth small ; lateral teeth long and lamel- 

 lar ; nacre white and iridescent. 



Hab. Alabama River, near Claiborne. Judge Tait. 



My Cabinet. 

 Diam. -6, Length 1, Breadth 1-7 inches. 



Shell elliptical, somewhat inflated, inequilateral; valves thick; 

 beaks somewhat prominent; ligament rather long and thin; epider- 

 mis yellow, smooth, with a few obsolete rays ; cardinal teeth small and 

 compressed ; lateral teeth long, lamellar, and nearly straight ; anterior 

 cicatrices distinct; posterior cicatrices confluent; dorsal cicatrices 

 placed in the interior of the cavity of the beaks; cavity of the shell 

 not very deep; cavity of the beaks small; nacre pearly white and iri- 

 descent. 



Remarks. — Among the number of fine shells sent to me some years 

 since by the late Judge Tait, was one whole specimen and an odd 

 valve of this shell. In hopes of procuring more and better specimens, 

 I delayed bringing it forward as a new species, and regret now to have 

 to figure and describe an individual not mature, the odd valve being 



VI. 2 B 



