38 SHELLS OF NEW ENGLAND. 
(from which, probably, Deshayes established his spe- 
cies,) in their less prominent carine, and their cine- 
reous color. 
The true position of the Vermetide is difficult to 
determine. ‘They have relations with the last two 
families in their shells, particularly in the plugging 
up of the upper whorls as the shell advances in 
growth. In the young animal, before its escape from 
the egg, the shell appears helicoid and reversed, thus 
showing some affinity with the Pyramidellide. As 
a description of the animal may be useful in this con- 
nection, I give it here. 
Its color is a light brown, with spots and patches 
of black. The mantle is fringed at its margin with 
short filaments. The branchial plume is very large 
and long, situated nearly over the middle of the back 
of the animal. ‘The foot is very short and broad, di- 
lated into rounded auricles anteriorly. The muzzle 
is broad, not cleft; the tongue small. The tentacles 
are short, conical, having the eyes at their external 
bases. An elevated ridge runs along the back, be- 
comes flattened into a membrane at the head, and 
passes round under the right tentacle, forming a kind 
of canal; near which is the anus. The operculum 
is corneous, concentric, black and hard on the inner, 
and lamellated on the outer surface. It is surround- 
ed by a thin, membranous, flexible portion, about one 
fourth its diameter ;— thus it is enabled to close its 
shell perfectly at the aperture, and yet to retreat far 
into the narrower whorls. 
