Descriptions of New Fluviatile Shells. 



elevated, with a nearly rectilinear outline ; whorls 10-11, flat 

 or concave, and with a well impressed, channelled suture ; 

 aperture small, rhomboidal, diaphanous, exhibiting the dark 

 band of the exterior through its substance very faintly, far 

 within. Columella deeply curved, not indented, thickened at 

 base ; outer lip angularly curved, extended forwards ; sinus 

 rather broad, not deep. 



Length 1.37 inch (34 millim.). Diam. 0.46 inch (12 millim.). 



Length of aperture 0.40 inch (10 millim.). 



Breadth of do. 0.24 inch (6 millim.). 



Habitat. Alabama. 

 My cabinet. 



Obs. A stout species, which most resembles M. regularis Lea 

 in general appearance, from which, however, its concave whorls, 

 elevated carina, and dark band will readily distinguish it. It 

 has not the channelled body whorl of M. canaliculata Say, nor 

 the convex, subangulated upper whorls which distinguish that 

 species. 



The lines of growth are very coarse and prominent, and ex- 

 tending over the raised line near the base of the whorls, give 

 the latter an interrupted or subcrenulated appearance. 



32. Ulelania gradata. 



Plate III. Fig. 12. 



T. conica, glabra, crassa, corneo-virente ; spira parum elevata ; anfr 

 7-8, gradatis, subconcavis, funiculo conspicuo suturas incumbente et in 

 angulum anfr. ultimi carinam elevante ; suturis valde impressis ; apertura 

 subrhomboidea, intus albida ; labro prorsum valde sinuato, coluraella 

 recta, in sinura angustum profundum procfticta. 



Shell conical, smooth, solid, greenish horn-color ; spire not 

 much elevated ; whorls 7-8, slightly concave, with a distinct 

 elevated ridge, closely overlying the suture and the projecting 



