﻿74 NEW UNIONIDvE OF THE 



means so brilliant in the nacre, nor is it so dark in the epidermis. It is also near to 

 fallax (nobis) . On the side there is a disposition to yellowness, which exhibits the 

 greenish rays. 



Unio othcaloogensis. PI. 14, fig. 54. 



Testa lam, subtriaDgulari, ventricosa, subaequilaterali; valvulis crassis, antice crassioribus ; natibus subgran- 

 dibus, ad apices undulatis ; epidermide lutescente, perlsevi, nitida, eradiata ; dentibus cardinalibus 

 crassis, obliquis, crenulatis et in utroque valvulvo duplicibus ; lateralibus brevibus subreetisque ; mar- 

 garita alba et iridescente. 

 Shell smooth, subtriangular, ventricose, subequilateral ; valves thick, thicker be- 

 fore ; beaks rather large, undulate at the tip ; epidermis yellowish, very smooth and 

 bright, without rays ; cardinal teeth thick, oblique, crenulate and double in both 

 valves ; lateral teeth short and nearly straight, nacre white and iridescent. 

 Proc. Acad. Nat. Sci. 1857, p. 32. 

 Bab. — Othcalooga Creek, Gordon County, Georgia. Bishop Elliott. 

 My cabinet and cabinet of Bishop Elliott. 

 Diam. "6, Length "7, Breadth *8 inches- 



Shell smooth, subtriangular, ventricose, nearly equilateral, obtuse behind and round 

 before ; substance of the shell thick, much thicker before ; beaks rather large, mi- 

 nutely undulate at the tip ; ligament very short and thin ; epidermis yellowish in- 

 clined to orange, very smooth, highly polished, bright, without rays, and with a 

 single line of growth near to the middle ; umbonial slope very much rounded ; cardi- 

 nal teeth very large, oblique, very much crenulated and double in both valves ; lat- 

 eral teeth short, lamellar, rather thick and nearly straight ; anterior cicatrices confluent 

 and very deeply impressed, posterior cicatrices confluent; dorsal cicatrices small, 

 placed nearly in the center of the cavity of the beak, under the cardinal tooth ; 

 cavity of the shell deep and rounded ; cavity of the beaks shallow and subangular ; 

 nacre white and iridescent. 



Soft Parts. — Branchial uterus situated on nearly two-thirds of the outer branchiae, 

 the branchial ovisacks being very full and comparatively large for so diminutive a 

 species, and number about twelve on each side ; the color whitish. Branchial very 

 small, rounded below, the inner one a little the larger, united the whole length of 

 abdominal sack. Palpi small, thin, transversely elongate, suboval, united a short dis- 

 tance on the posterior edges. Mantle thin, thickened at the palleal border and co- 

 lored at the edge, crenulate below the branchial opening where it is also deeply co- 

 lored and has a callus on each side. Branchial opening very small, with minute 

 brownish papillae on the inner edges. Anal opening very small, with very minute 

 papillae on the inner edges. Super-aiial opening proportionately large, not colored on 

 the edge, united for a short distance below. Color of the mass whitish. 



Embryonic shell clear white, subrotund, and very near to perplexus (nobis) in out- 

 line. 



