Descriptions of New Fluviatile Shells. 



remarkably elevated, but tapering regularly with a rectilinear 

 outline to the apex, which is entire and acute ; whorls 8, nearly 

 flat, upper ones carinate, and with a well defined suture ; body 

 whorl with a distinct angle, more distinct where it revolves 

 near the top of the aperture ; below this the base is rather con- 

 cave on the columella side ; aperture moderate, narrow, ovate, 

 whitish or faintly tinged with red within ; columella slightly 

 curved, not indented ; sinus slight, but well defined. 



Length 0.56 inch (14 millim.). Diam. 0.25 inch (6 millim.). 



Length of aperture 0.25 inch (6 millim.). 



Breadth of do. 0.13 inch (3 millim.). 



Habitat Tennessee. 



My cab. Cab. Lye. Nat. Hist., N. Y. 



Obs. A singularly neat, precise looking shell. Its trim 

 appearance, its pale color, unornamented by any band, and its 

 sharp, well defined angle, amounting almost to a carina, will 

 serve to distinguish it from all others. 



38. Melania tabulata. 



Plate IIL Fig. 18. 



T. ovato-comca, tenui, castaneo-nigra ; spira parum elevata ; anfr. 5, 

 superioribus, convexis, penultimo piano, superne angulato, ultimo in 

 planis pluribus tabulate ; suturis impressis ; apertura elongato-ovata, 

 ampla, intus purpurea ; columella vix incurva, in sinum inconspicuum 

 producta. 



Shell ovate-conic, smooth, thin, of a dark-brown color ex- 

 ternally ; spire not remarkably elevated, with a rather concave 

 outline ; whorls about 5, upper ones convex, penult whorl flat, 

 body whorl sub-angulated into several planes, with a distinctly 

 impressed suture ; aperture rather large, ovate, within of a 



