Descriptions of New Fluviatile Sheik. 



Shell elongate-ovate, smooth, moderately thick; of a pale 

 horn-color, with a faint, brown, narrow band on the penult 

 whorl, increased to two on the body whorl, and obsolete on the 

 apicial ones ; spire obtusely elevated, with a rather convex out- 

 line and a well defined suture ; whorls, four remaining, with 

 indications of two more lost by truncation, body whorl angu- 

 late, and rather coarsely striate longitudinally ; aperture rather 

 large, ovate, pale within, ornamented with the two bands of 

 the body whorl, which do not reach the outer edge, a broad, 

 plain area intervening; columella curved, with a very slight 

 sinus at base. 



Length 0.50 inch (12 millim.). Diam. 0.25 inch (6 millim.) 



Length of aperture 0.27 inch (7 millim.). 



Breadth of do. 0.15 inch (4 millim.). 



Habitat. Tennessee. 

 My cabinet. 



Obs. This is a very neat, pretty species, whose affinity with 

 any other is not so strong as to endanger its being easily con- 

 founded ; from M. angulata nobis, it differs in being broader, 

 less angulated, paler in color, less elongated, and by its brown 

 bands, that species being entirely plain. 



36. Ulelaiiia rhombica. 



Plate III. Fig. 16. 



Testa ovato-conica, fusco-virente ; spira parum elevata ; anfr. 6, su- 

 perioribus planis, striis 3-4 cinctis, ultimo multistriato, in medio angu- 

 lato, infra angulum striis obsoletioribus ; suturis inconspicuis ; apertura 

 ovata, intus albida ; columella incurva, sinum vix formante. 



Shell conic, rather thin, brown ; spire regularly pyramidal, 

 not elevated ; whorls about 6, flat, regularly and very dis- 



