418 Binney's Monograph of the Helices 
DESCRIPTION. 
Animal. Slate-color, rather darker on the head 
and neck ; foot narrow, terminating acutely. 
Shell. Depressed on the upper surface ; epidermis 
dark, approaching to chestnut-color, shining and 
smooth, with very minute, irregular, oblique striz 
beneath it; whorls rather more than four, the last 
very voluminous, and expanding transversely towards 
the aperture ; suture very little impressed ; aperture 
ample, sub-circular, within pearly or iridescent ; lip 
simple, thin, brittle, with a light testaceous deposit 
within ; umbilicus deep, not much expanded. 
Greatest transverse diameter more than an inch. . 
GEocRAPHICAL Disrrisution. Has been found in 
nearly all the Southern, Middle, and Western States. 
Mr. Say noticed it in Mexico. 
Remarks. The color of this shell varies pale 
light-greenish horn-color to a deep chestnut. The 
umbilicus varies considerably in size, but it is always 
distinct and profound. The surface, usually smooth 
and shining, is occasionally finely and regularly 
striated. The interior of the aperture exhibits, in 
perfect specimens, a beautiful pearly lustre. 
It is sometimes confounded with the next Pei 
but it may always be distinguished from that by 
attention to the following particulars. It is a much 
larger shell, yet the number of whorls is constantly. 
one less; the umbilicus is larger and deeper, the 
aperture more circular, and the deposit of testaceous 
matter within is less. The color of: the shell is 
usually much darker. The only living animal of this 
