description, says, it is so much like that of a Buccinum, that to 
make of the Sigaretus a Biiccinum, it is only necessary that the 
whorls of the shell should be less unequal, and should be elongated 
into a more acute spire The animal as delineated in his plate, 
or that part which is visible from above, consisting entirely of the 
expanse of the thick, fleshy mantle, is oval and convex. On the 
anterior margin, a little on the left, is a deep emargination, which 
is the extremity of an open canal beneath, originating above the 
neck in the branchial cavity, to which it conveys the water, and 
in which are two pectinated and vascular lamelliform branchiae. 
The shell is entirely enclosed in the convexity of the mantle. The 
head is formed as in Buccinum. The tentacula are conic, with 
the eyes at their base. The vent is posterior to the canal and 
before the middle of the body. The foot much smaller than the 
mantle and also oval. The sexes are in separate individuals. 
Blainville has formed a new genus under the name of Crgptos- 
toma, for one or two East Indian species, the shells of which 
though more depressed, are altogether generically similar to SigoL- 
retuSj in which other naturalists place them ) but the animal, 
agreeably to his description, differs in having a more elongated 
form, appendiculated tentacula and but one large branchial pecten. 
Sigaretus perspeotivus. — Specific character. Depressed; 
beneath, revolutions visible almost to the summit. 
Desc. Shell oval, very much depressed, but little convex, with 
numerous, transverse, slightly undulated, sub-equidistant, impress- 
ed lines and longitudinal wrinkles ; transverse lines obsolete 
beneath : spire not at all prominent, only a little convex : volutions 
about three : suture a simple impressed line : within, the slightly 
elevated line is more or less obvious, not reaching the margin of 
the labrum : revolution of the whorls visible almost to the summit. 
Ohs. This shell is abundant on the coast of New Jersey and 
farther south ; but I have never had an opportunity to examine the 
animal. 
I have carefully compared many specimens with a shell sent me 
by Mr. Gr. B. Sowerby, under the name of haliotoideuSy L., but 
which seems more accurately to correspond with the leachii, Blain- 
ville, as figured by Sowerby in his Grenera,^^ and of which Blain- 
ville has formed his genus Cryptostoma. So striking is the 
resemblance that I have hesitated much to consider it a distinct 
species. 
