UNIVALVE MOLLUSCA. 449 
the shell, but without operculum. The Volutes live on the sands 
near the shore; sometimes they are found high and dry, left by the 
retreating tide. Their shells, of various forms, are ornamented with 
the most lively colours, the surface covered with irregular lines, 
the tint of which is generally in strong contrast with that of the 
ground. 
Among the more remarkable species illustrated in PLaTE XX., 
we may note: Fig. I., Voluta undulata; Fig. I1., Voluta cymbium ; 
Fig. III., Voluta Delessertii, Fig. IV., Voluta musica ; Fig. V., Voluta 
imperialis; Fig. VI1., Voluta scapha; and Fig. VIL, Voluta vexillum. 
The third family, Conide, contains Pleurotoma and Conus. 
The genus Conus is especially rich in species, as well as numerous 
in individuals. The shells are much sought after by collectors, many 
being rare, and so command high prices. Those belonging to 
this group present a very remarkable uniformity of shape, at the 
same time that the colours are very fine, and much varied in design. 
The shell is thick, solid, inversely conical, wreathing spirally from the 
base to the apex, the spire being generally short, the last turn con- 
stituting alone the greater part of the surface of the shell. The 
opening extends nearly along its whole length, occupying all the 
height of the last whorl. It is always narrow, its edges quite parallel ; 
the columella presents neither fold nor curvature ; the right edge is 
plain, sharp, and thin, detached from the front of the last spiral by a 
sloping hollow, more or less deep, 
The animal creeps upon a foot, elongated, narrow, truncate in 
front, furnished behind witha horny rudimentary operculum, altogether 
insufficient to cover the opening. The head, which is large, is 
elongated into a little snout, or muzzle, at the base of which rises on 
either side a conical tentacle, having an.exterior eye upon its anterior 
extremity. At the extremity of the muzzle is the mouth, which is 
armed within with numerous horny teeth in pairs, elongate or hastate. 
A cylindrical syphon, reversing itself in the shell, serves the purpose 
of carrying water to the branchize or gills. ‘The shells inhabit the 
seas of warm countries, especially those lying between the Tropics, 
where they affect sandy coasts, with a depth of ten to twelve fathoms 
of water. ; 
Among the species bearing a spiral crown, we may mention the 
rare Conus cedo-nullt, of which several varieties are known, which come 
from the South American Seas and the Antilles. , 
Conus hebraica, from the shores of Asia, Africa, aud America, is a 
common species. It is white with black spots, which are. nearly 
square, arranged in transverse bands. 
DD 
