FAMILY PURPRLLVE — FUSUS. 149 



F. muricatus. (Gould, Op. cit. p. 293.) Shell slender. Whorls seven, very convex, with about ten 

 conspicuous vertical folds, crossed by coarse elevated revolving lines, making a rough almost tuber- 

 culated surface : canal straight, equalling half the length of the shell ; outer lip jagged by the 

 revolving lines, sometimes much thickened. Color, yellowish white or orange. Length, 0-7; 

 width, 0*3. Stomachs of fishes. Northern Coast. 



F. turriculus. (Gould, op. cit. 292. Pl. 36, fig. 340 of this work.) Shell small, thin. Whorls 

 seven or eight, angulated and turreted: surface with 12-14 prominent folds, and numerous distinct 

 revolving lines ; beak open, short and nearly straight, Color, white, yellowish or brownish white. 

 Length, 0*66; width, 0-25. Stomachs of fishes. 



GENUS PLEUROTOMA. Lamarck. 



Animal unknown, but probably not differing from that of Fusus. Shell fusiform or turreted, 

 generally ribbed : aperture oval, terminating in a canal more or less elongated ; lip simple, 

 thin, with a notch above. Columella smooth, nearly straight. 



Obs. This genus was first identified on our coast by Mr. Couthouy. It contains at present 

 three species, two of which have only been found in the stomachs of fishes. 



Pleurotoma bicarinata. 



PLATE VI. FIG. 113. 



Pleurotoma bicarinata. Couthouy, Journ. Nat. Hist. Vol. 2, p. 104, pl. 1, fig. 11. 

 P. id. Gould, Invertebrata of Mass. p. 281, fig. 186. 



Description. Shell minnte, tapering at both extremities, turreted. Whorls six, convex, 

 with numerous revolving ribs, and smaller ones intervening ; about the middle a deep groove, 

 with two prominent revolving ribs on each side : sutures clearly defined. Aperture narrow, 

 elliptical, ending in a short canal slightly inclining to the left : lip thin, toothed by the revolving 

 ribs, with a slight notch above ; pillar-lip arched at its upper third. 



Color. Whitish or slate-color, or dusky brown. 



Length, 0-3. Width, 0- 15. 



Stomachs of fishes on the northern coast. Very rare. 



