90 TRACHELIPODA. 



GeJius36.—CERIT}ilVM.—Brugmere. 



Generic Character. — Shell turreted ; aperture oblong, 

 oblique, terminated at the base by a short, truncated, re- 

 curved canal, without a notch; the outer lip with a groove 

 at its upper extremity; aperture provided with a small 

 horny operculum. 



This genus is allied to Pleurotoma, but the aperture is without tho 

 slit on the right margin. 



Cerithium semigranosiim. — The Semigranulated Ceri- 



! THIUM. Plate XII. fig. 9. Fusiform, turreted; apex acute ; 



i transverse minute strise, and sulcated granulations; the suture 

 with double spiral rows of large granules ; colour reddish- 

 brown. One inch and a half long. Inhabits the seas of 



I New Holland. 



I 



I Section II Phytiphaga. 



j Without a projecting siphon, generally respiring by an 

 orifice ; provided with jaws, and usually feeding on vege- 

 table substances; shell having the aperture entire, and des- 

 titute of a notch or canal. 



FAMILY I. TURBINACEA. 



Shell turreted, or conical, with an oblong or rounded 

 aperture, not expanding, and the margin disunited. 



Genus 37 TURRITELLA — Lamarck. 



Generic Character. — Shell turreted, not pearly; aperture 



rounded, entire ; margin disunited above ; the outer lip 



with a slight sinus, and the aperture furnished with a horny 



operculum. 



The genera Scalaria, Turbo, and Cerithium, are nearly allied to this 

 genus, but may easily be distinguished from them by a sinus on the 

 right margin of the apei-tm-e, which is only visible ^vhen the mouth is 

 quite perfect, and which does not exist in any other shells. 



