GASTEROPODA. 



141 



long, oval, having on the inside a few suddenly increasing 

 whorls, the outside having an indistinct spiral rib. 



These shells all have a shelly operculum. Grey has 

 formed out of slight differences in the animal the following 

 genera: — Uvanilla, Pamaulax, Pachypoma, Lithopoma, 

 Imperator, Tubicanthus, and Bolma. 



Astralium. Philip-pi. (Guildfordia Gray.) — Shell 

 conical, not umbilicated, the outer edge of the whorls 

 lengthened into radiated spines, the outer surface granu- 

 lated; the lip has near the suture a sinus, and is then 

 strongly curved forwards, which entirely separates this 

 genus from the preceding and following genera; oper- 

 culum, according to Gray, calcareous, flat, with a slight 

 rim near the outer edge. — 1 species. 



The only species is A. (Trochus) triumphans, from 

 Japan. 



Globulus. Shum. (Potella Lam. ; Helicina Gray, 

 not Lam.) — Shell small, flattish, but convex 

 both at the upper and under part ; outside 

 smooth and polished; left lip very much 

 thickened, and spreading over the under 

 surface, so as to form a callosity ; right lip 6 



. Globulus vestiaria. 



sharp at the edge ; operculum horny. Ani- 

 mal very similar to that of Turbo, but the eye stalks 

 strikingly long, and the foot having four filaments on each 

 side. — 10 species; also fossil. 



Small shells from the Mediterranean, Indian, and Java- 

 nese seas. G. vestiaria is the most common species. Some 

 found in the West Indies are said to be microscopic. 



TROCHU S. Lin. — Shell rather variable in shape, co- 

 nicaTpspire elevated ; circumference of the whorls more 

 or less angulated, often quite sharp; lower part of the 

 shell more or less flat; aperture depressed; edge of the 



