﻿UNITED STATES. 01 



Unio similis. PL 19, fig. 71. 



Testa leevi, elliptic*, subinflata, postice subbiangulata, valde inaequilaterali ; valvulis subcrassis ; natibus 

 prominulis ; epidermide tenebroso-fusca, radiata, polita ; dentibus cardinalibus subgrandibus, subeleva- 

 tis et subpyramidatis ; lateralibus sublongis subcurvisque ; margarita vcl purpurea vel alba vel salmonis 

 colore tincta, et iridescente. 



Shell smooth, elliptical, somewhat inflated, very inequilateral, subbiangular be- 

 hind ; valves somewhat thick ; beaks a little prominent ; epidermis dark brown, 

 radiated and polished; cardinal teeth rather large, somewhat elevated and pyramidal; 

 lateral teeth somewhat long and curved ; nacre purple, white or salmon color and 

 iridescent. 



Proc. Acad. Nat. Sci. 1857, p. 169. 



Hab. — Buckhead Creek, Burke County, Georgia. Bishop Elliott. 



My cabinet and cabinet of Bishop Elliott. 

 Diam. *8, Length 1*2, Breadth 2-3 inches. 



Shell smooth, elliptical, somewhat inflated, inequilateral, obtusely biangular behind 

 and subtruncate before; substance of the shell somewhat thick, slightly thicker 

 before ; beaks a little prominent ; ligament rather long and somewhat thick ; epider- 

 mis dark brown, radiated over the whole disk, polished on the umbones and striate 

 near the margin, with obscure rather distant lines of growth ; umbonial slope raised 

 and very much rounded ; cardinal teeth rather large, somewhat elevated into a pyra- 

 midal form, crenulate and slightly disposed to be double in the right valve ; lateral 

 teeth somewhat long, lamellar and slightly curved; anterior cicatrices distinct and 

 deeply impressed ; posterior cicatrices confluent, large and indistinctly impressed ; 

 dorsal cicatrices small, and placed in the centre of the cavity of the beaks ; cavity of 

 the shell rather deep and wide ; cavity of the beaks shallow and rounded ; nacre 

 purple, white or salmon color and iridescent. 



Soft Parts. — Branchial uterus filling nearly the whole of the outer branchiae. Bran- 

 chiae moderately large, rounded below, the inner ones somewhat the larger, free three 

 fourths of the length of the abdominal sack. Palpi small, suboval, thin, united only 

 at the upper part of the posterior edges. Mantle thin, slightly thickened at the 

 margin. Branchial opening rather large, with numerous dark brown papillae on the 

 inner edges. Anal opening large, with numerous very minute brown papillae on the 

 inner edges. Super-anal opening large, slightly colored within and united below for 

 a short distance. Color of the mass whitish. 



Embryonic shell clear white and very nearly the same form as Othcaloogensis (nobis.) 



Remarks. — This belongs to the group of which Oeddingsianus, (nobis,) may be con- 

 sidered the type. It is near to Whiteianus (nobis.) Its epidermis is polished like 

 both species. In the character of the rays it resembles Oeddingsianus . It is less 

 polished on the sides than Whiteianus, which usually has no rays. 



