* 
|; $ 
has 
inhabiting the United States. 415 
the aperture is less. 'The size of the umbilicus and 
the shape of the aperture are the same in both. But 
the principal distinction consists in the spiral lines 
which revolve on the whorl, intersecting the strie of 
growth, but so minute as hardly to be perceptible to 
the naked eye. The whitish, narrow band, shaded 
below, with rufous apparent on the outer, and some- 
times on the second whorl, generally aids in identify- 
ing it, though it is sometimes wanting. Young 
specimens are much more depressed than those of 
H. ligéra, and are sometimes distinctly carinated. 
The depression of the umbilical region is not so 
evident in pee as in the ponding — 
` $4, HELIX INDENTATA. 
Plate. XXII, fig. 3. 
H. testa depress convexiusculà, imperforata, tenuissimá, diaphand, 
nitida ; ultimo anfractu lineis i impressis, distantibus, radiatis ornato ; 
aj transversá ; labro simplici, acuto; basi indentato.- 
Synonyms AND REFERENCES. 
Helix indentata, Say. Journ. A, N. S. Philad., 
IL. 372 
DESCRIPTION. 
Animal. Bluish black upon the upper parts ; 
margin and posterior extremity lighter. 
Shell. Flattened, thin, pellueid ; epidermis high- 
ly polished, corneous ; whorls rather more than four, 
with regular, sub-equidistant, radiating, im 
lines, which on the body-whorl extend to the base, 
outer whorl expanding towards the aperture; aper- 
= 
