141 
VOLVARIA, Lamarck. 
Gen. Char. Shell cylindrical, convoluted; spire 
almost hidden ; aperture as long as the shell, 
narrow, widest towards the truncated base ; 
outer lip denticulated ; columella plaited. 
The principal characters of this Genus, as limited by 
Mr. G. B. Sowerby, are, the plaited columella, the 
striated surface, the truncated base, and the thin edge of 
the outer lip : by its convoluted form and short spire it 
is related to Bulla ; the plaits upon the columella form 
a resemblance to Marginella ; but its nearest affinity is 
to Acteon (Tornatella, Lam.), from which its concealed 
spire, numerous plaits, and truncated base distinguish it. 
The Genus, as established by Lamarck, contains several 
recent species, which Mr. G. B. Sowerby has justly ob- 
served are more naturally related to Marginella, from 
which however they differ in some characters. The 
striated surface* f om whence arises the denticulated 
edge of the lip, is important as a generic character, be- 
cause it indicates the presence of an epidermis, and that 
the shell was never enveloped in the mantle of its in- 
habitant ; and thus marks a decided distance between it 
and the recent shells Lamarck has arranged vyitli it. 
