94 G. & H. Nevill — Descriptions of new Marine Mollusca. [No. 2, 



MS., the greater thickness of shell, straighter outer lip, and less oblique 

 longitudinal ribs seem, however, to distinguish the present form. Shell 

 ovately conical, thick, apex mammillate ; white, with a broad brown stain on 

 the back of the last whorls ; whorls 7, the first three embryonal, the next 

 three angular, the longitudinal ribs only beginning towards the base of each 

 of them, give the appearance of a row of nodules just above the suture ; 

 the last whorl unusually straight and regular, with an excavated shelf at the 

 top, transversely and closely striated, strise somewhat obscure, peculiarly 

 undulating and interrupted, decussated with somewhat indistinct longi- 

 tudinal almost straight ribs, commencing at the base of the excavated shelf ; 

 regularly and closely denticulated both on the rather widely spreading 

 callosity covering the columella and also just within the margin of the 

 straight outer lip ; aperture contracted, much straighter and narrower than 

 in Reeve's figure of coniforinis. 



Long. 7f, diam. 4 mil. 



Apparently very scarce, four specimens in sand from Mauritius and one 

 from Port Blair, Andamans. 



Cythara Isseli, n. sp., PI. VII, Fig. 17. 



Shell thick, ovately conical, suture very distinct, apex pointed ; 

 white, with an orange band in the middle of the whorls, the band repeated 

 on the last whorl, this band is distinct on the longitudinal ribs, but only 

 here and there traceable in their interstices ; whorls seven, the first three 

 embryonal (in dead specimens nearly always wanting), the others longi- 

 tudinally concentrically ribbed, ribs very thick, throughout closely trans- 

 versely striated ; columella nearly straight with a moderate sized callosity, 

 closely covered with distinct granules and transverse rugosities ; aperture 

 narrow, widening somewhat abruptly near the base, sinus moderate, outer 

 lip thickly reflected, transversely striated, slightly rounded, a row of large, 

 regular granules just within the aperture. 



Long. 7f, diam. 4 mil. (decollated specimen of four whorls only). 



Common in sand from Balapiti, Ceylon. 



I have named this shell after M. Issel of Genoa, whose works on the 

 shells of the Red Sea, Persia, and Borneo, afford most valuable aid in 

 determining our Indian Ocean shells. 



(Coll. Indian Museum, Rev. J. Warneford, M. Issel and H. Nevill.) 



Cythaba Isseli, var. Ceenica, (? sp. nov.), PI. VII, Fig. 16. 



Considerably smaller than the type form, the entire, full grown figured 

 specimen being only 6| in length and 2f mil. in breadth ; there is apparently 

 no other difference, except that the sinus is a trifle less distinct, and the 

 aperture a little straighter, 



Mauritius, — rare. 



