364 
MOLLUSCA. 
less coated with a vitreous covering or enamel-like glaze, probably secreted by the mantle. The columella is 
uniformly curved, and it is believed that none of the species have hitherto been found in the New World.” — 
BroderipJ] [The Melo, Broderip, resembles Cymba ; but its apex, instead of being shapeless and rude, takes a 
well-fashioned and spirally-marked form. The colouring of the shell is also more elegant and vivid.] Others 
(Voluta, Montf.) have the last whorl conoid, narrowing at the end opposed to the spire. The foot is less than in 
the preceding genus. Their shells ai'e often very remarkable for the beauty of the colours and patterns which are 
painted on their surface. [There is reason to believe that the genera Cymba, Melo, and Voluta, are viviparous.] 
Marginella, Lam., with the form of the Voluta, has the outer lip thickened and revolute. The sinus is slightly 
marked. According to Adanson, the foot is also less, and has no operculum. The animal can partially cover its 
shell by raising the lobes of its cloak. The tentacula have the eyes upon the outer side at their base. M. de La- 
marck distinguishes among them the Colombella, by the more numerous plaits 
on the shell, and by a swelling of the middle of the outer lip. It appears 
that there is no operculum. Mitra, Lam., has an oblong aperture with some 
large folds on its columella, of which those next the spire are the largest. 
Their spire is generally long and pointed. Several species are brilliantly 
spotted with red upon a white ground. Their animal has a small foot, tenta- 
cula of moderate length, with the eyes on the side one-third above the roots, 
and a moderate siphon ; but it will often protrude a proboscis longer than the 
shell. [The genus Conohelix, of Swainson, has a form more conical than the 
typical Mitrse ; but its claim to be a good genus is denied by Sowerby.] Can- 
cellaria, Lam. — The last whorl ventricose, and the aperture ample and round, 
with a plate upon the columella : the spire is prominent, pointed, and the surface marked in general with cancel- 
lated striae. [According to Sowerby, this genus is nearly allied to Purpura.] 
Fig. 177- — Colombella. 
The Whelks {Buccinum, Linu.)* — 
Comprise all the shells furnished with an emargination, or short canal, bent to the left, and whose 
columella is not plaited. Bruguieres made four genera of them ; viz., Buccinum, Purpura, Cassis, and 
Terehra ; which MM. de Lamarck and Montfort have still further subdivided. 
Buccinum, Drug., comprises the emarginated shells without any canal, the general form being oval, as well as 
the aperture. The animals where known have no veil on the head,— a proboscis, two widely separate tentacula 
with the eyes on their outer bases, and a horny operculum. The siphon is prolonged beyond the shell. M. de 
Lamarck specially reserves the name Buccinum to such as have 
the columella convex and naked, and the outer lip without 
ribs or varix. Their foot is moderate in size ; their proboscis 
long and thick, and their penis often excessively large. [The 
shell of the remarkable genus named Trichotropis by Broderip 
and Sowerby, is turbinated and keeled ; its aperture is wider 
and rather longer than the spire ; the base entire : but imme- 
diately below the obliquely truncated columella there is an in- 
distinct canal. The shell is thin and delicate, covered with an 
epidermis forming numerous sharp-pointed bristle-like pro" 
cesses on the edges of the carinae outside the shell. The horny 
operculum is much smaller than the aperture. The animal 
resembles a Buccinum, differing from it principally in having 
only a very small fold of the mantle to line the nearly obsolete 
canal of the shell. There is a British species {T. borealis).'] 
Nassa has the columella covered by a plate more or less thick 
and broad, and the emargination deep, but without a canal. 
The animal resembles that of Buccinum, and there are shells intermediate between the two genera. Lamarck 
names Eburna those which join to a smooth shell, without plaits on the lip, a pillar that is deeply and widely 
umbilicated. In general form their shell has a strong resemblance to the Olives. [There is no operculum.] The 
animal is unknown. The Ancillaria, Lam., has also a smooth shell, and at the base of 
the columella a striated appendage or varix, without an umbilicu-s, and without a 
groove round the spire. The animal, in such species as it has been observed in, is 
similar to that of Oliva, and has the foot even more developed. The same naturalist 
unites those which are ribbed in the direction of the whorls, under the generic name 
of Dolium : the lower whorl is very large and ventricose. Montfort again subdivides 
Dolium into the Dolium proper, where the base of the columella is as it were twisted ; 
and into Perdix, where it is sharp. Their animal has a very large foot, dilated in 
front ; a proboscis longer than its shell ; slender tentacula ; eyes at their exterior 
side near the base ; the head without a veil, and the foot without an operculum. 
Harpa is easily recognized by the prominent ribs which cross the whorls, and of 
which the last forms a rim to the margin of the aperture. The shells are beautiful. The animal has a very large 
Forms tlie family Entoinosto7nu of Blaiiiville. 
