34 MOLLUSCA. TRACHELIPODA. 



P. Lapillus, Lam. Shell ovate-acute, transversely silicate, scabrous, 

 longitudinally striated, generally white ; whorls convex ; spire 

 conical ; lip thick, dentate within. 1^ inch long. Inhabits the 

 shores of Europe Penn. Brit. Zool. iv. pi. 74, fig. 1. 

 This extremely common shell is generally white, not unfrequently yellow, some- 

 times yellow, banded with white, and occasionally dark brown. In sheltered situa- 

 tions it is very scabrous, and in this state is the P. imbricata of Lam. This species 

 also affords a purple dye ; and an account of the method by which it is procured is 

 given by Mr Cole in an early volume of the Philosophical Transactions. 



Gen. 0. RICINULA, Lam. 



Shell ovate, generally tubercular or spinous externally ; aper- 

 ture longitudinal, presenting a short recurvate canal, ter- 

 minated by an oblique notch ; unequal teeth on the columel- 

 la, and the inner side of the right lip frequently narrowing 

 the aperture. 



The Ricinulae are small shells of an oval form, generally covered with tubercles, 

 and having the aperture of a bluish or purple tint. 



R. horrida, Lam. Shell obovate, subglobose, covered with short, 

 thick, black tubercles ; the interstices white ; spire very short ; 

 aperture gaping, purple. 1^ inch long. Inhabits the Indian 

 Ocean. Bonan. 3. fig. 173. 



1 . With an ascending or recurved canal. 



Gen. 21. CASSIS, Lam. Buccinum, Lin. 

 Shell gibbous ; aperture longitudinal, narrow, ending in a short 

 canal, suddenly reflected towards the back ; columella trans- 

 versely plicate or rugose ; outer lip generally dentate. 



The species of this genus inhabit the seas of warm climates, and are in general of 

 an inflated ovate form, with a short spire. Many of them are possessed of great 

 beauty. 



* Spire marked with longitudinal prominences. 



C. Madagascariensis, Lam. Shell ovate ventricose, whitish, with 

 three transverse rows of dorsal tubercles ; lower surface flesh-co- 

 loured ; aperture blackish purple, glossy, with white teeth. Near- 

 ly a foot long. Inhabits seas of Madagascar. Lam. vii. 219. 



C.flammea, Lam. Shell ovate, inflated, subtrigonal, with four or 

 five transverse series of tubercles, bluish-gray, with reddish- 

 brown longitudinal markings; spire convex, mucronate; colu- 

 mella red, rugose. 6 inches long. Inhabits the seas of the West 

 Indies. -Lister, pi. 1004, fig, 69. 



** Spire without prominences. 



C. rufa, Lam. Shell ovato-ventricose, very thick and ponderous, 

 tubercular, red, with several series of thick knobs ; spire short, 

 mucronate ; columella and outer lip deep yellowish-red. 5J inches 

 long. Indian seas. Favanne, pi. 26, fig. D. 2. 



C. testiculug, Lam. Shell .ovato-oblong, transversely and longitu- 

 dinally striated, brownish, with darker red spots in transverse 

 rows ; spire short, convex, mucronate ; aperture narrow, ru- 



