376 RISSOINA. 



R. OBELISCUS, Recluz. PI. 54, fig. 9. 



Solid, white, a little shining, semipellucid, with 12-13 strong, 

 elevated costse, cutting the basal rib into tubercles, thinly, closely 

 spirally striate ; whorls 8-9, turreted, with deep, undulating suture; 

 lip strongly, nodosely varicose. Length, 4*5 mill. 



Mauritius, Upolu. 



It is R. Schwartziana, Dunker (from the latter locality.) 

 R. COSTATA, A. Ad. PL 56, fig. 57. 



Opaque, solid, white, with strong, elevated, longitudinal ribs, sub- 

 angulated above, closely spirally striate ; whorls 7, flatly convex, 

 suture undulated ; columella subtuberculate below, lip subdilated, 

 flexuous, strongly varicose. Length, 4'7 mill. 



Cobija, Peru ; Philippines, f 

 R. BAXTERIANA, Nevill. PI. 56, fig. 75. 



Solid, shining, white, with close, large, rounded longitudinal ribs, 

 constricted into three spiral series of nodules, base spirally sulcate ; 

 lip thick, but scarcely varicose. Length, 3 mill. 



Red Sea. 



Weinkauff suggests that this is the juvenile of R. nodicincta, A. 

 Ad., but I scarcely think so. 

 R. SUBDEBILIS, Nevill. PI. 55, fig. 36; PI. 56, fig. 55. 



Shell solid, whitish, with about 14 compressed, suboblique ribs 

 and slight spiral strire, the ribs abruptly terminated by two or three 

 basal spiral riblets; whorls about 12, slightly convex, suture sub- 

 channeled. Length, 6*5 mill. 



Mauritius. 



It is R. canaliculata, Sowb. (fig. 55). Nevill, who has indicated 

 a var. perlanceolata, thinks this may R. debilis, Garrett. 

 R. WEINKAUFFIANA, Nevill. PI. 56, fig. 61. 



Rather solid, brownish white, with narrow, rather close, sub- 

 flexuous ribs, and numerous, less distinct spiral striae, base very in- 

 distinctly doubly ridged ; lip smoothly varicose. Length, 6'75 mill. 



Andaman Is. 



It is not unlikely that this will prove identical with the preceding 

 species. In the original figure the ribs are shaded and the inter- 

 stices left light, an error which has been carefully copied in my illus- 

 tration. 



R. MINUTA, Nevill. PI. 56, fig. 65. 



Shining, white, with longitudinal, thick, slightly oblique, some- 

 what irregular ribs, and smooth interstices; whorls 8, angularly 



