330 RISSOIA. 



R. DESMARESTI, Audouin. PL 67, fig. 67. 



Thin, elevated conical, with 10-12 low longitudinal costse, fading 

 out towards the base ; whorls 6, slopingly flattened, suture distinct ; 

 peristome simple. Length, 3 mill. 



Red Sea. 

 R. WAABITICA, Issel. PL 68, fig. 98. 



Rimate, somewhat solid, a little shining, opaque, white, longitu- 

 dinally thinly costate, sculpture fading above the middle of the 

 body whorl ; interstices spirally striate ; whorls 44, slightly convex, 

 with distinct suture ; lip simple. Length, 1*3 mill. 



Red Sea. 

 R. PSAMMITICA, Issel. PL 68, fig. 99. 



Rimate, fragile, subopaque, slightly shining, white, densely de- 

 cussated by longitudinal ribs, fading out anteriorly, and close spiral 

 striae; whorls 4-1, suture a little impressed ; peristome thin. 



Length, 1 mill. 



Red Sea. 



Section PERSEPHONA (Leach. 1852), Monts. 1884. 



R. VIOLACEA, Desm. PL 62, figs. 37-39. 



Solid, with subangulate periphery; longitudinal ribs 10, short on 

 the last whorl, which is ornamented with spiral series of puncta- 

 tions ; lip externally thickened ; whitish, purplish on the spire, the 

 periphery purple-zoned, peristome violaceous, the varix white. 



Length, 5'3 mill. 



Europe. 



It is R. punctata, Potiez, R. purpurea, McAndrew, R. amethystina, 

 Renier. 

 Var. RUFILABRUM, Alder. Fig. 38. 



Corneous, yellowish or greenish yellow, not banded, lip chestnut 

 color. 



It is R. hyalina, Desm. 

 Var. PORIFERA, Loven. Fig. 39. 



Corneous or yellowish, periphery rounded ; without ribs, deeply 

 spirally pitted ; peristome chestnut color. 



Var. ecostata, Jeffreys, is a synonym. 



Section SCHWARTZIA, Bucq., Dautz., Dollf. 1884. 



R. MONODONTA, Bivona. PL 62, fig. 41. 



Thick, hyaline, very smooth, shining, last whorl sometimes -a 

 little angulated ; aperture expanded below, lip varicose exteriorly, 



