442 _MAZATLAN UNIVALVES 
Hab.—N orway to Mediterranean, Forbes.—W. Indies, B, M.— 
(Var. Yod.) Mazatlan ; 34sp. living on Spondylus, dead on 
Chama; L’pool Col. 
Tablet 2027 contains 4 sp. of different ages. The largest 
possesses its operculum, which appears like that of Chrysallida, 
but with the ruge much coarser. Another is broken so as to* 
shew the axis of the upper whirls. 
Famity CERITHIOPSIDA. 
Gents CERITHIOPSIS, Forbes & Hani. 
Br. Moll. vol. iii. p. 364.—H. & A. Ad. Gen. vol. i. p. 239.— 
Operculum concentric, nucleus terminal. 
P Non Cerithiopsis, Andrew, Ann. Mag. Nat. Hist. vol. x. p. 105. 
Cerithium, pars, auct.—The position of the following species 
must of course remain in abeyance till the animals have been 
examined, or at least the opercula observed. The speci- 
mens found were not sufficiently numerous to make out the 
species satisfactorily. 
Sf 
557. CERITHIOPSIS TUBERCULOIDES, 2. Ss. 
C. t. “C. tuberculato” simili, sed inulio minghe tuberculis 
minoribus ; anfr. v. primis levibus, tumidis, subdiaphanis, 
plerumque decollatis ; anfr. normalibus, lineis radiantibus 
usque ad carinam quartam non tuberculatam circa peripheriam 
continuis ; bast int. juniore angulatd, sublevi; in t. adultad 
carinulis ii. tumidioribus ; labio tenwissimo. 
Comp. C. tuberculatum, Mont. in Forbes § Hanl. Br. Moll. 
vol. 11. p. 365. 
Comp. Cerithium Peruvianum, D’ Orb. B. M. Cat. Moil. p. 43, 
no. 375. 
The shell is smaller even than dwarf specimens of the British 
species, and the tubercles are further apart; else the full des- 
eription in the Br. Moll. would apply almost exactly to the 
Mazatlan shell. The smallest sp. with three normal whirls 
measures ‘055 by °027 ; the largest, with seven, long. °15, 
long. spir. 105, lat. ‘048, div. 23°. 
