98 



SHELLS AND SHELL-FISH. 



and is^ therefore, but a subordinate character. Nume- 

 rous as is this family, nearly all the species are confined 

 to warm latitudes, particularly those of the tropics. It 

 is hardly necessary to add, that the whole are predaceous, 

 and consequently carnivorous. 



(87.) The VoLUTiD^ arrange themselves into five 

 primary groups. — 1. The Volutins, or typical vo- 

 lutes, having a short spire more or less papillary, and 

 the lower plaits upon the pillar largest ; the foot is 

 excessively large, and envelopes the sides of the shell. 

 2. The MiTRiN.B, or mitres, where the spire is always 

 acute, generally longer than the aperture, and the lower 

 plaits smallest ; the foot small, not dilated on the sides, 

 and the siphon (a) rather long, as in M'ltra sangiiisuga. 



i^fig. 5.) The first is the typical, and the second sub- 

 typical. The three aberrant sub-families are, — 3. The 

 Olivine, or olives : cylindrical in shape ; the aperture 

 linear, and the pillar thickened and confusedly plaited. 

 4. Ancillaria : the aperture wide, and the base of the 

 pillar alone thickened and striated. 5. The jVIarginel- 

 LiNiE, or date-shells, having plaits upon the pillar, and 

 crenated teeth on the thickened outer lip ; the foot 



