166 CHLOROSTOMA. 







Trochus nigerrimus GMEL., Syst. Nat., xiii, p. 3572. PHILIPPI, 

 Conchyl. Cab., t. 10, f. 13. LISCHKE, Jap. Meeres- Conchyl., p. 97, t. 

 7, f. 6, 7 (not Turbo nigerrimus GMEL.,=Monodonta nigerrima (Gm.) 

 (Phil.) Trochus niger, umbilicatus, etc., CHEMNITZ, Conchyl. Cab., v, 

 p. 98, f. 1647. T. niger PHILIPPI, Conchyl. Cab., p. 369. FISCHER, 

 Coq. Viv., p. 372, t. 113, f. 4. Chlorostoma corrugation A. ADAMS, 

 P. Z. S., 1851, p. 182. Chlorostoma undatella GOULD, Proc. Bost. 

 Soc. N. H., 1861, p. 20. 



This species is most nearly allied to C. argyrostoma, and in the 

 sculpture differs from that form only in the rather smaller folds 

 above, and the lack of distinct spiral striae or lir?e. It is smaller than 

 argyrostoma, more depressed, and always umbilicated. 



C. RUSTICA Gmelin. PI. 25, figs. 1, 2, 3, 4. 



Shell umbilicate, conic, heavy, solid, chocolate-colored or brownish- 

 olivaceous ; spire conical, more or less elevated ; suture distinctly 

 impressed ; whorls 6-7, moderately convex or nearly flat, sometimes 

 tumid just below the sutures, and either smooth or longitudinally 

 plicate, the folds usually obsolescent, and visible only for a short 

 distance below the sutures ; spirally obsoletely striate ; body-whorl 

 obtusely angular at the periphery ; base nearly flat ; aperture very 

 oblique ; columella with one or two teeth below, expanded above in 

 a white callus, which half surrounds the narrow, deep circular 

 umbilicus. Alt. 33, diam. 32 mill. 



Japan. 



Trochus rusticus GMEL., Synt. Nat., xiii, p. 3572. PHILIPPI, 

 Conchyl. Cab., p. 48, t. 10, f. 11, 12. FISCHER, Coq. Viv., p. 163, t. 

 55, f. 1, t. 112, f. 2. LISCHKE, Jap. Meeres- Conchyl., p. 97. 



Periphery less sharply carinate than in C. uordmanni and C. 

 pfeifferi ; less strongly sculptured than C. carpenteri, and not lirate 

 beneath ; more elevated than C. nigerrima and not nearly so finely 

 corrugated above. 



C. NIURICOLOR Bunker. PL 26, figs. 21, 22. 



Shell conoid, imperforate, obsoletely striate, black ; whorls plano- 

 convex, the last subangulate, base convex,, dull reddish or yellow- 

 ish ; umbilical callus green, pitted ; columella very oblique, uniden- 

 tate ; fauces smooth, pearly. Alt. 17, diam. 28 mill. (Dunker.) 



Japan. 



Trochus nigricolor DKR., Malak. Blot., 1860, p. 237, and Moll. 

 Jap., p. 22, t. 3, f. 2. LISCHKE, Jap. Meer ex- Conchyl., p. 100, t, 7, f. 



