aperture; volutions six, wrinkled ; spire convex ; aperture sub! u- 
nate, narrower beneath ; wdthin, a prominent tooth near the base, 
distant from the margin ; labrum simple, umbilicus rather small, 
orbicular, profound ; region of the umbilicus indented. 
Greatest breadth more than one-fifth of an inch. Inhabits 
Pennsylvania. ^ 
I found a few specimens of this shell on the farm of my friend 
Mr. Reuben Haines, at Germantown. 
With the exception of the size and the armature of the throat, 
it is somewhat of the habit of U. ligera, JVoh. ; but the opacity of 
the body whorl near the aperture, is much more remarkable. 
These characters, combined with that of the tooth, will readily 
distinguish this species from any other. 
PoLYGYRA FATiGiATA. — Shell couvex beneath, nearly plane 
above, the spire being hardly perceptibly elevated ; whorls a little 
over six, compressed, acutely carinated, crossed by numerous 
raised, equidistant lines, which form grooves between them ; 
superior surface not at all convex ; aperture subreniform ; labrum 
reflected, regularly arctuated, describing two-thirds of a circle ; 
within two-toothed, lower tooth conic obtuse, superior tooth com- 
pressed, transverse, placed further within the aperture than the 
inner, one from which it separated by a wide and deep and 
obvious sinus ; labrum with a very profound duplicatiire, which 
has a concave surface, but with no emargination near its acute 
tip ; beneath exhibiting only two volutions, wdthout any distinct 
groove on the external one near the suture ; beneath the carina 
the elevated lines are obsolete. 
Greatest breadth seven-tw'entieths of an inch. 
Found by Mr. Lesueur in the vicinity of New Harmony. It is 
very closely allied to that species which I described under the 
name of 'plicata ; the character of the mouth is very similar, but 
in that shell, such is the situation and form of the teeth of the 
labrum, that at first view they do not seem to be separated by a 
remarkable sinus, and the inferior tooth is compressed and larger 
than the other ; the duplicatiire of its labium is emarginate near 
the tip. The present species is also larger, carinated, and the 
elevated lines are obsolete below the carina. 
ITelicina occulta. — Carinated ; carina almost concealed on 
the spire, and nearly obsolete on the body whorl ; whorls about 
