162 Trans. Acad. Sci. of St. Louis. 
formed below the convexity of the body whorl, and a spiral 
sculpture of coarse subequal lyrae. The embryo is conoidal, 
compact and closely coiled, multispiral, or composed of about 
three whorls. The body whorls are evenly convex and 
coarsely ribbed, the subsutural collar not well defined. The 
columella is biplicate. The two species before me are both 
from the Upper Claiborne ferruginous sand, and may be defined 
as follows : — 
Form very stout, the spiral lyrae coarser and more close-set, separated by 
scarcely their own width on the peripheral convexity, though widely 
separated below on the body whorl; columellar plicae moderately 
strong and extremely oblique. Length of a specimen of 5 body whorls, 
17.0 M5; WIG, Wb MM. Ge wSUS] vcs elapse aieele wees bless plicata Lea 
Form less stout, smaller in size, the spiral lyrae finer, separated by about 
twice their width on the convexity of the body whorl, the central of 
the fine intermediate threads more pronounced than in plicata; 
columellar plicae very strong and much less oblique. Length of an 
equally well grown specimen of 5 body whorls, 13.5 mm.; width, 5.5 
WIN sicjsiotatinie lela Ne alelnc oisbisisloieijes tecime mists Weiieiametemine extricata n. sp. 
Varicobela n. gen. 
The shell here is of moderately large size, thick substance 
and very stout form, with strongly elevated rounded varices, 
usually about five in number on the first four body whorls. 
The embryo is large, broadly and regularly conoidal, much 
widerthan high and composed of about three whorls. The 
body whorls are broadly and evenly convex, without 
pronounced peripheral prominence, having numerous long 
and rather narrow, elevated and obliquely sigmoid ribs 
and many fine lines of growth, which are cut by equally 
fine and regular spiral threads, producing a _ regular 
but very minute clathration; every fourth spiral thread 
is larger, these becoming strong and widely spaced lyrae on 
the body whorl below the convexity; aperture half as long as 
the shell, oblique, the canal very short but narrow and rather 
well differentiated. The inner lip is callous throughout and 
there are no columellar plicae. The type of this genus, 
rendered very isolated by the varices so unusual in the Pleuro- 
tomidae, is the Strombus smithi, of Aldrich, occurring in the 
upper Eocene strata at Red Bluff, Miss. A specimen of 4 
