104 DESCRIPTION OP NEW 



group, and it has been with some hesitation that I have added another 

 species. The dolahrseformis stands between ovatus (Say) and occidens 

 (nobis), and when young I should suppose would resemble U. globosiis 

 (Lea). This shell was among those sent by Lewis Leconte, Esq. to 

 his brother, to whom I am greatly indebted for the possession of many 

 fine species. The strong resemblance this species bore to the occi- 

 dens (nobis) induced me to defer, when I described the other new 

 ones, the description of this for better specimens to decide upon. The 

 acquisition of several fine ones from Professor Ravenel no longer left 

 any doubt in my mind of the propriety of proposing it as a new spe- 

 cies. The female shell, like the occidens, is very broad at the posterior 

 margin. 



Unio Novi-Eboraci. Plate XXIV. fig. 114. 



Tesla elliplicd, subcompressa, incBquilaterali ; valvulis subcrassis ; natibus subprominen- 

 tibus, ad apices undulalis; epidermide luteola, radiala ; denlibus cardinalibus magnis erec- 

 tisque ; laleralibus longis reclisque ; margarila alba et iridescenle. 



Shell elliptical, somewhat compressed, inequilateral; valves rather thick; beaks 

 somewhat prominent, undulated at the tip; epidermis yellow and radiated; cardinal 

 teeth large and erect; lateral teeth long and straight; nacre white and iridescent. 



Hab. Oak Orchard Creek, Orleans County, New York. J. C. Jay, 

 M.D. 



My Cabinet. 

 Cabinet of Dr Jay. 

 Diam. -7, Length I'l, Breadth 2-2 inches. 



Shell elliptical, somewhat compressed, inequilateral; substance of 

 the shell rather thick, thinner on the posterior portion ; beaks some- 

 what prominent, and minutely undulated at the tip ; epidermis yellow, 

 with green rays nearly over the whole disk ; cardinal teeth large, erect 

 and deeply cleft in the left valve-, lateral teeth long, straight, and sepa- 

 rated from the cardinal teeth ; anterior cicatrices distinct ; posterior 

 cicatrices confluent; dorsal cicatrices placed in the centre of the cavi- 

 ty of the beaks; cavity of the shell shallow; cavity of the beaks sub- 



