LIMNiEA. 



103 



19. LIMN^A SMITHSONIANA, Lea. 



Plate 18, fig. 2. 



Shell fusiform, rather thin, reddish-brown, 

 slightly transparent, slightly umbilicate, very 

 minutely and transversely striate ; spire ob- 

 tuse ; sutures impressed ; whorls six, convex ; 

 aperture rather large, ovate, brown within the 

 margin ; outer lip expanded ; columella some- 

 what thickened and scarcely plicate. 



Length 12, diam. 8 mill. 



Loup Fork of the Platte River. 



Very like L. humilis, Say, but much larger. 



20. LIMN^A FERRUGINEA, Haldeman. 

 Hald. Monog. 49, t. 18, figs. 19, 20. 



(77) 



