442 MAZATLAN UNIVALVES 



Ha b. -Norway to Mediterranean, Forbes. W. Indies, B. M. - 

 (Far. Yod.) Mazatlan ; 34 sp. 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 ruga? much coarser. Another is broken so as to 

 shew the axis of the upper whirls. 



FAMILY CEBITHIOPSID^. 



GENUS [CEEITHIOPSIS, Forbes $ Hani. 



Br. Moll. vol. iii. p. 364. J?. fy A. Ad. Gen. vol. i. p. 239. 

 Operculum concentric, nucleus terminal. 



PNon Cerithiopsis, Andrew, Ann. Mag. Nat. Hist. vol. x. p. 105. 



Cerithium, pars, auct. The position of the following species 

 jnust 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. 



557. CEEITHIOPSIS TTJBEECULOIDES, n. s. 



C.t. " C. tuber culato" simili, sed multo minore ; tuber culis 

 minoribus ; anfr. v. primis Icevibus, tumidis, subdiapkanis, 

 plerumgue decollatis ; anfr. normalibus, lineis radiantibus 

 usque ad carinam quartam non tuberculatam circa peripJieriam 

 continuis ; basi in t. junior e angulata, sublcevi ; in t. adult d 

 carinulis ii. tumidioribus ; labio tenuissimo. 



Comp. C. tuberculatum, Mont, in Forbes fy Hani. Br. Moll. 



vol. iii. p. 365. 

 Comp. Cerithium Peruvianum, D'Orb. IB. M^Cat. Moll. 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- 

 cription 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, lot. "048, div. 23. 



(/. 0.^, 



I 



