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. II., Voluta cymbium ; 

 Fig. III., Voluta Delessertii ; Fig. IV., Voluta musica ; Fig. V., Voluta 

 imperialis ; Fig. VI. , Voluta scapha; and Fig. VII., Voluta vexillum. 



The third family, Conidce, contains Pleurotoma and Conus. 



The genus Conns 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 with a 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 branchiae 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 Conns cedo-mtlli, 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. 

 P 



