MOLLUSl i. 501 



67. Cerithiiun albovaricosum. (Plate XLIV. fig. Q.) 

 Cerithium gracile, Pease (?jo« Lamarck), Proc. Zuol. Soc. 1800, p. 132. 



Shell thin, elongate-pyramidal, whitish or livid white, sparsely 

 spotted between the costse with small narrow lines. Whorls about 

 14, convex at the sides, separated by a deep, subcanaliculate suture, 

 slowly increasing, longitudinally finely costate, and spirally Urate, 

 exhibiting at irregular subdistant intervals larger snow-white 

 varices. Cost;e about ten to fifteen on the upper whorls, and 

 somewhat nodulous through being crossed by the fine transverse 

 line, of which there are about four principal ones, several liner in- 

 tervening. Last whorl with a prominenl varix at the left side 

 opposite the labrum, which is thinnish and somewhat expanded 

 and grooved within. Aperture roundish ovate, oblique, contracted 

 anteriorly into a narrow also oblique canal, sometimes (not always) 

 stained with black. Columella well incurved, covered with a thin 

 callosity bearing an elongate transverse tubercle at the upper part. 

 Length 14imillim., diam. 4^-. 



Providence Reef, Mascarenes, in 24 fins. ; Sandwich Islands 

 (Pease). 



G. rostratum of Sowerby is allied to this species, but may be dis- 

 tinguished by its more angular whorls, different costse, less deep 

 suture, and the different and more regular dotting between the 

 nodules round the middle of the whorls. Specimens from the Sand- 

 wich Islands of this species in the British Museum have not a black 

 anterior canal, and the costse are rather finer than in the Mascarene 

 specimen. 



68. Cerithium amirantium. (Plate XLIY. fig. R.) 



Shell small, elongate, light pink, faintly dotted with brown. 

 Whorls about 12, slightly convex, nodulously costate, spirally Urate, 

 exhibiting at distant intervals paler thickish varices. Costse about 

 15 on the upper whorls, crossed by two principal transverse lira?, 

 which are nodulous upon the ribs, giving the whorls a biangulate 

 appearance at the sides. In addition to these two there are several 

 (about seven) finer lirse, but which scarcely form nodules upon the 

 costse. The body-whorl has the usual varix on the left side well 

 developed, swollen. The aperture is round-ovate, acuminate above 

 and prolonged anteriorly into an oblique, short, recurved canal. 

 Columella arcuate, coated with a rosy callus, oearing an elongate 

 transverse tubercle above. Labrum thickened by a small external 

 varix. Length 15 millim., diam. 4^-. 



Darros Island, Amirantes, in 22 fms. 



This pretty little species agrees with G. tenellum, Sowerby, in 

 colour, but is narrower and differently sculptured. 



69. Cerithium ( Rhino clavis) acutinodulosum. 

 (Plate XLIV. fig. S.) 



Shell elongate-pyramidal, white, spotted with brown between 



