54 NEW UNIONID.B OF THE 



Eah. — Oostanaula River, Floyd County, Georgia, and Etowah River. Rev. 

 Geo. White. 



My cabinet and cabinet of Mr. White. 

 Diam. -5, Length -9, Breadth 1-7 inches. 



Shell smooth, elliptical, compressed, flattened on the sides, very inequilateral, sub- 

 angular behind; substance of the shell thick; beaks slightly prominent, placed to- 

 wards the anterior margin ; ligament rather short and thin ; epidermis dark olive, 

 striate, obsoletely rayed, with distant marks of growth ; posterior slope but slightly 

 elevated ; umbonial slope obtusely angular ; cardinal teeth small, short and thick ; 

 lateral teeth long, thick, curved and enlarged at the posterior end ; anterior cicatrices 

 distinct; posterior cicatrices confluent; dorsal cicatrices placed over the centre of the 

 cavity of the beaks; cavity of the shell very shallow ; cavity of the beaks very shal- 

 low and subangular ; nacre white or purple. 



EemarJcs. — This species belongs properly to the group of which the U. gihbosns, 

 Barnes, may be considered the type. It has a strong resemblance to some of the 

 young of the less wide varieties of that species. It is, however, more regularly oval, 

 is a smaller shell, and not so oblique. It is more closely allied to U. luridus, (nobis,) 

 and U. arctior, (nobis ;) but is more enlarged and less angular than those species in the 

 posterior portion. The diameter is greater about one-third from the posterior end, 

 which is rarely the case with any Unio; hence, the umbonial slope is enlarged. The 

 old specimens generally become dark brown. Nine specimens are before me, all of 

 which have a white nacre but one, which is slightly salmon in the cavity of the 

 beaks. I have specimens from Dr. Hale, from Red River, Arkansas, which seem to 

 me to be larger varieties of this species. 



Unio Elliottii. PI. 7, fig. 37. 



Testa grandfe plicatii, subquadratS,, inflata, vald6 inequilaterali ; valvulis percrassis; natibus prominentibus, 

 tumidis, ad apices undulatis ; epidermide nigra, nitidaj dentibus cardinalibus per magois, in utroque 

 valvulo duplicibus ; lateralibus crassis, longis, lamellatis subcurvisque ; margarita argentea et irides- 

 cente. 

 Shell largely folded, subquadrate, inflated, very inequihitenil ; valves very thick ; 

 beaks somewhat prominent, swollen, undulate at the tip : epidermis black, shining ; 

 cardinal teeth very large, double in both valves; lateral teeth thick, long, lamellar 

 and rather curved ; nacre silvery white and iridescent. 

 Proc. Acad. Nat. Sei. 1856, p. 262. 



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



My cabinet and cabinet of Bishop Elliott. 

 Diam. 2-6, Length 45, Breadth 5-3 inches. 



Shell with numerous large folds, nearly quadrilateral, inflated, very inequilateral, 

 rounded before ; substance of the shell very thick, thicker before ; beaks somewhat 

 pionainent, incurved and undulate at the tip; ligament rather short and very thick; 



