﻿26 G. and H. Nevill — On New Marine Mollusca. [No. 1, 



shilling and smooth, the rest longitudinally sculptured with oblique, some- 

 what indistinct and distant undulations, disappearing altogether on the lat- 

 ter half of the last whorls, spirally striated throughout, striae close and 

 somewhat scabrous, causing the outer lip to be minutely but regularly den- 

 ticulated ; columella abruptly twisted backwards, making a sharp angle at the 

 base of the aperture. This species resembles R. nivea, A. Ad. from Australia, 

 but is a smaller shell, composed of fewer whorls, spirally striated throughout, 

 instead of only on the basal portion of the last whorl, the ribs also are not 

 so strongly developed and are more oblique, the peculiar formation of the 

 aperture and its canal are, however^ exactly similar. 



Long. 2i Mil., Diam. 1 Mil. 



An damans. 



RiSSOINA PEECEASSA, n. sp., PI. I. Fig. 13. 



Shell large, very thick, white ; whorls seven, angularly turreted, the 

 last equal in size to the other six, the first five sculptured with very 

 massive, longitudinal ribs, on the last two whorls the sculpture is obso- 

 lete, traces only can be seen near the columella, the last whorl has a trans- 

 verse, rather indistinct furrow beneath the suture and a very broad, rounded 

 and callous rib, extending from the top of the aperture to the margin of the 

 outer lip, becoming somewhat indistinct near its termination ; columella 

 thickened and reflected, outer lip very thick and callous, angled near the centre 

 at the point where the previously mentioned rib joins it. The furrow below the 

 suture and the broad rib near the base of the last whorl are characteristics 

 not known in any other species of the genus j it is also a more callous shell. 



Long. 8 Mil., Diam. 3 Mil. 



Mauritius. Rare. 



Aecuella, n. sub-gen. 

 Differing from typical species of Eulima by regular spiral striation and 

 by the columella being twisted back, so as to form an acute angle at the 

 base of the aperture. 



Eulima [Aecuella] mieifica, n. sp., PI. I. Fig. 10. 



Shell slender, aciculate, white and shining ; whorls fifteen, very narrow 

 and tortuous, regularly and closely but very minutely spirally striated 

 throughout, a somewhat superficial groove is apparent^ a little below the 

 centre, on all except the last and first five or six whorls ; columella thicken- 

 ed, twisted and bent backwards, forming a sharp angle at its junction with 

 the outer lip ; interior of the aperture striated ; varices certainly exist on 

 the whorls, but they are too indistinct to be traced satisfactorily ; in shape 

 this shell somewhat resembles Eulima tortuosa, Ad. and Rv. 



Long. 8 Mil., Diam. 1^ Mil. 



Ceylon, A single specimen only has been found. 



