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. WAAIUTICA, 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 4o, slightly con vex, 

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



Bed 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, Me Andrew, R. amethystina, 

 Renier. 



Var. RUFILABRUM, Alder. Fig. 38. 



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

 color. 



It is R. hyalina, Desm. 

 Var. PORIPERA, 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, 



