390 RISSOINA. 



Appears to differ from the foregoing species, in being usually 

 narrower, with as many or more whorls, although smaller in size. 



R. ORYZA, Garrett. PL 59, fig. 47, 53, 52, 56. 



Solid, smooth, shining, white, spire rapidly tapering, with obtuse 

 apex; whorls 6-7, flatly convex, suture broadly margined; lip 

 thick, dilated, columella oblique. Length, 2 mill. 



Viti Islands (Garrett), Persian Gulf, Mauritius (Weinkauff), 

 Japan (Adams). 



R. Stoppani, Weink., not Issel (fig. 53), and R. subulina, Weink. 

 (fig. 52), from Japan, are synonyms ; the latter a somewhat larger 

 shell (3'75 mill), having 8 whorls. The Red Sea fossil species, 

 which Issel called R. /Stoppani, has no margined suture. * 



Var. SUBL.EVIGATA, Nevill. Fig. 56. 



Appears 1o differ principally in the aperture being more broadly 

 rounded below. 



Indian Ocean, Polynesia. 



R. L.EVIGATA, C. B. Adams. PI. 59, figs. 48, 50. 



Shining, pellucid, smooth, white ; whorls 9-10, slightly convex, 

 suture white-margined ; lip subdilated, externally thickened. 



Length, 4'5 mill. 



West Indies. 



The above is the description of R. vitrea, C. B. Ad. (fig. 50), 

 which appears to be the adult of the earlier described R. Icevigato. 



R. BROWNIANA, d'Orb. PI. 59, figs. 45, 46. 



Solid, polished, white, usually with two or three chestnut bands 

 on the last whorl, bi maculate near the aperture ; whorls 8-9, slightly 

 convex ; suture not margined; lip thickened externally. 



Length, 4'7 mill. 



West Indies. 



R. Icevissima, C. B. Ad., is a synonym, according to Morch, etc. 

 The figure, however, as given in Reeve's Iconica (fig. 46), appears 

 more nearly related to the next species. 



R. SLOANIANA, d'Orb. PL 59, fig. 49. 



Thick, white, smooth, polished; whorls 5-6, flatly convex, suture 

 not margined ; lip externally thickened, with usually two internal 

 callous teeth. Length, 3'8 mill. 



West Indies. 



Besides frequently being possessed of apertural teeth, this species 

 is stouter, with fewer whorls than the preceding one. 



