36 MOLLUSCA. TIIACHELIPODA. 



S. Mauritianus, Lin. Shell oblong, smooth, white, transversely 

 banded with reddish angulate lines ; spire short, longitudinally 

 plicate, mucronate ; lip rose-colour within and striated. 2f in- 

 ches long. Inhabits Indian seas. Lister, pi. 849, fig. 4, a. 



S. pugilis, Lin. Shell turbinate, ventricose, reddish yellow ; the 

 last whorl crowned with tubercles, the middle smooth, and the 

 base sulcated ; spire muricated, with spreading tubercles, trans- 

 versely striated ; lip with the anterior lobe short, rounded, and 

 sulcated towards the base. 3^ inches long. Inhabits American 

 seas. Lister, pi. 864, fig. 19. 



Gen. 24. PTEROCERA, Lam. Strombus* Lin. 

 Shell ovate, ventricose, ending below in an elongated canal ; 

 outer lip dilating with age into a digitate wing, having a si- 

 nus near the base ; spire short. 



Most of the Pterocera acquire a large size. They inhabit the seas of warm cli- 

 mates. 



P. lambis, Lam. Shell ovate and tuberculated, with seven digita- 

 tions ; the terminal ones straight ; spire conical, acute ; colour 

 grayish, mottled with brown ; aperture smooth, orange-coloured. 

 O'T| inches long between the extremities of the terminal digita- 

 tions. Seas of India. D'Argenv. pi. 14, fig. E. 



P. chiragra, Lin. Shell ovate and tuberculated, white, spotted 

 with brown ; with six strong, curved diverging claws projecting 

 on either side ; outer lip rose-coloured, striated with white within. 

 Length, without the digitations, 6^ inches. Inhabits the seas of 

 India Bonan. fig. 3, 314, 315. 



This shell is singular from the digitations on the opposite sides, which give.it 

 some appearance of a spider. When the shell is incomplete, or without the digi- 

 tated expansions, the species is scarcely to be recognized, were it not for the charac- 

 ters afforded by the spire. 



Gen. 25. ROSTELLARIA, Lam. Strombus, Lin. 

 Shell fusiform or subturriculate, terminated below by a rostri- 

 form canal ; outer lip entire or dentate, more or less dilated 

 with age, and having a sinus contiguous to the canal. 



R. curvirostris, Lam. Shell fusiform, turreted, ponderous, smooth, 

 very minutely striated transversely, brownish yellow; whorls 

 somewhat convex, the highest obsoletely plicate ; aperture white ; 

 outer lip dentate ; rostrum short and curved. 7 inches long. 

 Inhabits Indian seas. Lister, pi. 854, fig. 12. 



R. rectirostris, Lam. Shell fusiform, turreted, smooth in the mid- 

 dle, dirty white ; whorls somewhat convex, the last transversely 

 sulcate below ; the higher more convex and cancellated ; outer 

 lip dentate at the margin ; rostrum very long and quite straight. 

 6 inches long. Inhabits Indian seas. Bonan. fig. 131 . 



R. pes-pelecani, Lam. Shell turreted, reddish gray ; the turns an- 

 gulate, and nodose in the middle ; outer lip palmate, divided 

 into three digitations, which are acute and divaricate ; canal ob- 



