1S75.] Gr. & H. Nevill — Descriptions of new Marine Mollusca. 87 



C. rttgosa, var. fallax, nobis. 



This is probably the form that induced Pease incorrectly to make 

 scalarina -a synonym of rugosa. This dwarf variety has 9 longitudinal ribs on 

 the last whorl, the four transverse keels are less unequal in size, there is 

 only one brown line on the last whorl and within the aperture (in this 

 respect only does it agree with scalarina) ; the peculiar straight outer lip and 

 consequently contracted aperture, as also the form of the whorls and suture, 

 are the same as in the type form. 



Long. 4|, diam. 2 mil. (last whorl, long. 2). 



Common at Mauritius and Bourbon ; rare at Ceylon. 



Clathurella scalarina, Desh. 



Specimens in the Museum agree exactly with the typical figure (especi- 

 ally as regards the rounded outer lip and open aperture) ; suture scarcely 

 excavated, spirally minutely striated, six transverse keels on each whorl (the 

 first and last somewhat indistinct), 12 longitudinal ribs on the last whorl 

 (not 15 to 16 as in the original description) ; apex and suture stained 

 an intense brown, only one brown line on the last whorl and within the 

 aperture. 



Long. 6, diam. 1\ mil. (last whorl, long. 2^). 



Abundant at Balapiti in Ceylon ; rare at Mauritius. 



Clathurella exquisita, n. sp. 



We found this shell marked in the British Museum as Clathurella 

 nebulosa, Pease, but it differs totally from the shell described under that 

 name (P. Z. S., 1860, p. 143), being of a beautiful pink colour with a white 

 transverse band, not white with interrupted longitudinal brown lines as in 

 Pease's description of P. nebulosa ; it may rather prove to be a small 

 variety of the shell described and figured by Pease from Paumotus (Am. J. 

 Conch., 1868, p. 219) as Clathurella canaliculata ; however, even if it should 

 prove so, our name exquisita will stand for the species, as Reeve described a 

 totally different shell as P. {Clathurella) canaliculata, P. Z. S., 1848 ; if the 

 Paumotus shell proves to be distinct from our Mauritius one, as we think it is, 

 we would suggest for the former the name of Clathurella Peasei. C. exquisita 

 differs from C. Peasei by the absence of the dark brown line beneath the 

 transverse white band, by its suture not being coloured brown, by tha 

 much greater contraction of the last whorl and the outer lip at their base, 

 thus making a more prominent canal, by the last whorl having onlv 12 

 longitudinal ribs instead of 14, finally by its smaller size. We have not 

 thought it necessary to figure this species, as it is one that cannot be 

 mistaken. 



Long. 9f , diam. 4 mil. 



Rather scai'ce at Mauritius. 

 12 



