26 Melvill, Molluscan Fauna of the Arabian Sea, etc. 



Hitherto this shell must have been mixed up with 

 T. radiatus Gmelin, from which, however, we can always 

 distinguish it. Some points of difference consist in the 

 apex never being orange tinted, the whorls uniform and 

 more vivid green, the interstitial lirse between the granular 

 striations being absent in all the specimens examined, the 

 diametric measurement less in proportion to the altitude 

 than in either T. radiatus Gmel., or T. vividus Reeve (the 

 nearest approach to our species) and the false umbilicus 

 more profound, and narrower. The general form is like- 

 wise more acutely narrowly conical. 



Mr. Hugh Fulton has rendered me most valuable 

 assistance in the elucidation of this and other critical 

 species in Mr. Townsend's and Commander Shopland's* 

 collections ; and it gives me much pleasure to connect 

 this interesting species with his name. 



CaLLIOSTOMA DURICASTELLUM, Sp. 710V. 



(PL I, f 140 



C. testa perforata, pyraniidaio-conica^pallide rufo-ochracea, 

 solida, elegante, anfractibus octo, haud prominulis apud 

 suturas, undique spiraliter arete et delieate punctosuleatis, 

 infra, juxta suturas, et ultimo apud peripheriam spiraliter 

 bifuniculato, squarrose rufotessellato, in medio interdum 

 unicolore, interdum oblique rubrisparso et maculato, ultimo ad 

 peripheriam acutangulato, basi eoncinne spiraliter sulculosa, 

 hie illie rubri-pieta, apertura oblique quadrata, intus iri- 

 descente, labro extus tenui, simpliei. 



Alt. lo, diam. 7-50 mm. 



Hab. Batticaloa, Ceylon (Captain Tindall). 



A pretty Trochoid shell, allied to C. polychroma Ad., 

 C. interruptum Wood, and others of that section of the 

 genus. The shell is perforate, pyramidal, the whorls close 

 set, and not prominent at the sutures, the spiral puncto- 



* c.f. Ann. ^ Mag. N. H., Ser. 7, Vol. I., (1898) p. 194 sqq. 



