42 NEW UNIONIDJi:, MELANID^, ETC., 



Unio orapultis. pi. 15, fig. 40. 



Testa liBvi, obliqua, veutrlcosa, ad umbones valde tumida, valde insequilaterali, postioe rotundata, antice 

 truneata; valvulis percrassis, autice crassioribus ; natibus valde prominentibus crassisque; epider- 

 mide luteo-fusca, eradiata ; dentibus oardinalibus percrassis, pyramidatis, corrugatis, in utroque val- 

 vule duplicibus ; lateralibus percrassis, corrugatis, obliquis subcurvisque ; margarita alba et paulum 

 iridescente. 



Shell smooth, oblique, very much inflated, much swollen towards the beaks, very 

 inequilateral, rounded behind, truncate before ; A^alves very thick, thicker before ; 

 beaks very prominent and thick ; epidermis yellowish brown, without rays ; cardinal 

 teeth very thick, pyramidal, corrugate, double in both valves ; lateral teeth very 

 thick, corrugate, oblique and somewhat curved ; nacre white and somewhat irides- 

 cent. 



Proc. Acad. Nat. Sci., 1861, p. -39. 



Hah. — Etowah River, Georgia, Rev. G. White. 



My cabinet and cabinet of Mr. White. 

 Diam. 1, Length 1-2, Breadth 1-5 inches.. 



Shell smooth, oblique, very much inflated, swollen at the beaks, very inequilateral, 

 almost terminal, rounded before and truncate behind ; substance of the shell very 

 thick, thicker before ; beaks very prominent and thick ; ligament short and 

 thick; epidermis yellowish brown, more yellow on the inferior portions and browner 

 above, without rays, with many close equidistant marks of growth ; umbonial slope 

 much raised and rounded ; posterior slope broad and flat, cordate, with a broad in- 

 distinct furrow on each valve from the beaks to the posterior margin ; cardinal teeth 

 very thick, pyramidal, corrugate and double in both valves ; lateral teeth very thick, 

 corrugate, oblique and slightly curved ; anterior cicatrices distinct, small, very deep- 

 ly impressed ; posterior cicatrices distinct, rather small and deeply impressed ; dor- 

 sal cicatrices placed on the base of the cardinal tooth in the cavity of the beaks ; 

 cavity of the shell rather shallow and rounded ; cavity of the beaks shallow and ob- 

 tusely angular; nacre white and slightly iridescent. 



RemarJcs. — This belongs to the group of oblique species which are disposed to ro- 

 tundity. It is nearly allied to cor, Con., but it is rather more rotund, and although 

 remarkably high in the beaks, is not so much so, by any means, as that remarkable 

 species. The beaks of the only specimen which came into my possession are much 

 eroded, and therefore the undulations, if they had any, could not be observed. In per- 

 fect specimens the beaks no doubt will be found to be incurved. The cardinal tooth 

 in the left valve, described as being double, is disposed, in this specimen, to be 

 trifid, and the lateral tooth in tlie same valve is very much thickened and disposed 



