106 AMERICAN JOURNAL 



encircled by two plain keel-like ribs. The modesta (of which we 

 have perfect specimens from Annaa) is elongate, canal produced 

 and whorls traversed by three prominent ribs, of which the 

 middle is distinctly granulose ; apex and base white. 



Triton nitidulus, Sow, 



1831. Proc. Zool. Soc. London, p. 71. 



" "Var. Ceylonensis, Sow., P. Z. S. London, p. 71. 

 1844. Conch. Icon., sp. 70—73. 



My collection contains an extensive series of the above species 

 from its original locality, Island Annaa, from thence ranging 

 through Central and West Polynesia. From among specimens 

 furnished the late Mr. Cuming, he selected and returned me T. 

 Ceylonensis, which I had previously classed as a variety. It is 

 smaller than the type and distinctly granulose. There is still 

 another variety, slender, elongate and straight. At Annaa it 

 is more distinctly spotted. The character and arrangement of 

 the varices on the species of this division of the Tritons, are 

 useful guides in the determination of species. On the T. dis- 

 tortus and tortuosus, (which are synonymous,) the varices com- 

 mence at the labial varix and pass up obliquely over the whorls, 

 in a continuous series, making one revolution around the spire. 

 The sculpture of the shell is continued over them. On the niti- 

 dulus they commence just within and adjoining the labial varix, 

 extending down over the aperture, forming the callosity spoken 

 of by Mr. Reeve, and pass up more distantly from each other, 

 making two revolutions of the spire, and are smooth and white, 

 except on specimens strongly granulated. Those on T. obscurus 

 commence in the same manner as on distortus, are wide apart, 

 making usually three revolutions of the spire, and are blotched 

 or spotted with brown. 



Triton distortus, Schub. and Wagn. 



1795. Conch. Cab. Supp., p. 138, pi. 231, fig. 4074-75. 



1833. Triton distortus, Sow., P. Z. S. London, p. 71. 

 1844. " " Rve., Conch. Icon., sp. 66. 



" " tortuosus, Rve., " " sp. 74. 



The tortuosus does not depart sufficiently from the type to 

 be considered even a variety. It occurs in Polynesia, at all 

 localities, associated with distortus. At the Hawaiian Islands 

 specimens occur much more slender and elongate than any 

 described, and wholly of a brown color, on which the granules 

 are smaller and regular in size and shape. 



