9 
cularly joined to the outer lip at the base. Outer lip reflected 
hack upon the whorl, and incorporated with it near the base, with 
a deep sinus in the middle. Beneath, one quarter of an inch. 
Lister, Tab. 93, f. 94 ? 
Inhabits moist places ; common. In the collection of the Aca- 
demy. This species appears to be somewhat allied to H. hispida, 
but is sufiiciently distinct. Found by Mr. Lardner Yanuxem. 
H. PERSPECTIVA. — Shell very much depressed, with about six 
whorls ; whorls striated across, with raised, parallel, acute lines, 
forming strongly impressed sulcae between them. Umbilicus very 
large, resembling an inverted spire, in diameter at least equal to 
the breadth of the body whorl, and exhibiting distinctly all the 
votutions. Diameter three quarters of an inch. Found by Mr. 
Lesueur near Lake Erie. 
H. LINEATA. — Shell very much depressed, somewhat discoidal. 
Whorls about four, each longer than broad, with numerous raised, 
parallel, equidistant, regular, revolving lines. Suture impressed. 
Umbilicus very large, diameter at least equal to the breadth of 
the body-whorl, and exhibiting all the volutions distinctly. Aper- 
ture longer than wide, lunate. Diameter three-twentieths of an 
inch, nearly. 
Collection of the Academy. 
Found by Mr. Robert E. GrifiGith, near Philadelphia. Some- 
what resembles the last, but is more depressed, and the striae are 
transverse, not longitudinal, as in that shell ; the cavity beneath, 
also, though of equal proportional diameter, is not proportionally 
deep. 
H. THYRoroTTS.— P. 123 et seqq., October 1817. Shell thin, 
fragile, convex, umbilicate ; whorls five, obtusely wrinkled, or 
rather with equidistant, gradually elevated, obtuse lines ; and 
spirally striate, with minute, impressed lines ; lip widely reflected, 
white and flat before, partially concealing the umbilicus ; pillar- 
lip furnished with a very oblique tooth. Breadth four-fifths to 
nine-tenths of an inch. 
This species very much resembles H. albolabris of Nicholson’s 
Encyc., Amer. ed., but is umbilicated, and toothed on the pillar- 
lip. It is much less common. This shell was indicated in the 
American edition of the Encyclopaedia, but its characters were not 
laid down. 
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