338 IIAZATIAN UNIVALVES 



the different development of the tubercles on the same whirl, 

 the axis has occasionally a bent appearance. Gould's type 

 appears to have been nibbed smooth and faded. The opercu- 

 lum is not large for the sheU, and closely resembles that of 

 C. maculosum. The nucleus however is not sunken ; the 

 surface is not minutely striated, the outer margin is irregularly 

 indented, and the markings of the muscular scar are coarser. 

 The upper whirls are few in proportion, with the same diver- 

 gence as the adult. Long. 1'4, loTig. spir. '8, lat. '66, div. 40*. 



Sah. — Acapulco, Humboldt Sf Bonpland. — Panama & Taboga ; 



at and above half tide level ; mostly in the margin of water 



left in the rocks by the tide ; very common, C. B. Adams. — 



G-ulf of California and G-alapagos, Sowerby, (Mus. Cuming.) — 



S. W. Mexico, P. P. C— Mazatlan ; abundant ; L'pool Col. 



Tablet 1593 contains 7 sp. different ages, elongated. — 1594, 



8 sp. do. broader. — 1595, 3. sp. adult ; of which one (dead) has 



marine attachments. — 1596, 2 sp. lob-sided. — 1597, 2 do. pale 



state. — 1598, 1 sp. with operculiim. — 1599, 1 sp. with mended 



fracture.— 1600, 2 sp., one with Balanus, the other bored by a 



Proboscidean ; extremely rare. — 1601, 9 opercula. 



388. Cerithium intereupttjm, Mke. 



Cerithium interruptum, Mke. in Zeit f. Mai. 1850. p. 178, 

 no. 41. — C. B. Ad. Pan. ShelU, no. 198, p. 153.— (Non 

 Cerithium iixterruptum, Lam. An. s. Vert. vol. ix. p. 328, 

 no. 1. Fos. Grignou.)* 



? + Ceritliium , sp. iud. C. B. Ad. loc. cit. no. 199. 



Comp. Cerithium (Tympanotonus) Galapaginis, A. Ad. in Sow. 

 Tlies. Conch, p. 869, no. 85, pi. 182, f. L55-6. 



This species agrees exactly with both the figure and the 

 diagnosis of C. Galapaginis, but that shell is classed with Tym- 

 Ijanotonus, witlx wliich this has no connection. It begins witli 

 three smooth whirls, which soon fall off: then a few in which 

 the sculpture is wholly in spiral bra?, of which one just above 

 the suture is stronger, angiilatiug the periphery ; at this stage 

 the base is scarcely notclied, and the shell closely resembles 

 Trichotropis : afterwards the angular ridge subsides, the spiral 

 Knes become granuloso and the whirls somewhat roimded. 



• Should this imperfectly characterized shell prove to belong to the same genas, 

 Menke's name must he altered. If C. G.ilapa^inis be identical, th;»t may bs- 

 retained. If not, it may, according to custom, take the name of C. Meukei. 



