888 



Rather thick, cancellated with knotted cross-ribs, generally 

 having thickened, sometimes white, varices. The shell is of a 

 brown-colour, with a white band in the middle of the whorls. 

 Ileal Llejos, Central America, at the roots of mangroves, TL 

 Cuming. The narrower variety, without varices, we believe to be 

 C. Helicoide of C. B. Adams. 



170. Cerithium MbucHii (pi. clxxxvi. f. 283), A. Adams 

 (Cerithidea). 



Cerith. testa subcylindrica, decollata, albo-cserulescente, longi- 

 tudinaliter costata, spiraliter sulcata; anfractibus subventricosis, 

 gradatim crescentibus ; apertura undatim subquadrata; labio ex- 

 terno paululi^im incrassata. Variat sulcis rubro-lineatis. 



A northern species, in some degree resembling C. varicosa, but 

 not reticulated, having rounded ribs crossed by spiral sulci, which 

 in one variety are marked by a red line. The general tint is 

 bluish-white. The shell is rather cylindrical, and in Mr. Cuming's 

 two specimens, decollated. 



171. Cerithium Montagnei (pi. clxxxvi. f. 284, 285, 286), 

 B'Orbigni/, Voy. dans FAm. Mcr. Moll. C. Eeevianura et C. 

 pulchrum, C. B. Adams. C. Largilliertii, miippi, Abbild. t. 1. 

 f. 7. C. Portunei, Adams. 



Cerith. testa ventricosa, conica, laevigata, longitudinalitcr cos- 

 tcllata, fusco et fulvo pallido spiraliter fasciata ; anfractibus decern, 

 ventricosis, subito crescentibus, ultimo magno, subtiis carinato, 

 inde striato ; sutura profunda ; apertura magna ; labio externo 

 late expanso et reflexo ; columella tortua, crassa. 



C. varlcosum is reticulated, this is smooth, ribbed above, and 

 has a keel and stria; under the whorls. In some specimens how- 

 ever there are faint traces of cross-bars above. The form is 

 conical, the whorls rapidly enlarging. C. Largilliertii is the 

 rather plain shell we have figured, with a scarcely expanded, pro- 

 bably unformed, outer lip, 



172. Cerithium bicarinatum (pi. clxxxvi. f. 288), Gray, 

 Fauna of New Zealand. C. lutulentum, Kiener, Sp. Gen. Coq. 

 pi. 22. f. 3. 



Cerith. testa pyramidali, fusco-nigricante, ad suturam albo 

 lineata, longitudinalitcr costata, snbtiis spiraliter acute bicarinata ; 

 apertura subquadrata ; canali subproducto. 



We have not seen any fully formed specimens of this New 

 Zealand shell, which is remarkable for the two sharp keels bor- 

 dering the lower part of the last whorl. 



