42 TROCHUS. 



to the base, its edge simple ; umbilical area deep, rather narrow, 

 white, smooth, with a spiral rib just inside the margin, and with its 

 outer border tinged with red. 



Alt. 14, diam. 16 mill ; alt. 18, diam. 21 mill. 



Indian ; Madagascar ; Zanzibar ; Red Sea ; Chinese Seas ; 

 Lieivkiew Is. (Philippi.) 



T. cariniferus Beck in Reeve, Conch. Syst. ii, t. 118, f. 8, 1842. 

 (no description). — Philippi, Conch. Gab., t. 38, f. 6; — Fischer, Coq. 

 Viv., p. 229, t. 75, f. 1, 2. 



The straight columella shows this species to be nearly related to 

 T. erythra^us. The description is drawn from typical examples from 

 Madagascar. A variety differing in coloration is figured by Fischer. 

 (see pi. 5, fig, 40). 



Section C(ELOtrochus Fischer, 1880. 

 Coelotrochus Fischer, Coq. Viv., p. 417. 



T. TiARATUS Quoy et Gaim. PL 12 figs. 72-74. 



Shell very deeply false-umbilicate, depressed conical, rather thin; 

 spire with slightly convex outlines; apex acute, lemon yellow when 

 eroded ; whorls 5 to 5^*, nearly planulate, but the upper margin of 

 each whorl prominent and projecting beyond the periphery of the 

 preceding ; last whorl carinated at the peri|)hery ; sculi)ture above 

 consisting of spiral lirie, about 5 to 8 on each whorl, cut into close 

 oblique beads, the interstices obliquely finely striate, one or two 

 of the broader ones usually with a central riblet ; color whitish or 

 yellowish, finely tessellated or articulated with reddish brown, the 

 tessellations formed by the disintegration of narrow radiating stripes, 

 which are on the base frequently continuous ; base nearly flat, with 

 seven or eight concentric close fine line, which are crenulated in a 

 peculiarly irregular manner by distinct short oblique impressed 

 marks, the interstices finely rad lately striate ; aperture subrhomboi- 

 dal, smooth within ; columella oblique, nearly straight, with an 

 obsolete, scarcely perceptible fold above, inserted upon the side of the 

 umbilicus, not in its center ; umbilical area white or yellow, smooth ; 

 false-umbilicus deep and narrow, but partly filled by a white callus, 

 not tapering to a point. Alt. 10, diam. l-Sj mill. 



T. tiaratus Q. et G., Voy. de V Astrolabe, iii, p. 256, t. 64, f 6-11, 

 1832.— Kiener, Spec. Troque, t. 22, f. 2.— Hutton, Cat. Mar. Moll. 

 N. Z., p. 36.— Fischer, Coq. Viv. p. 90.— and of other authors.— T. 



