RISSOINA. 373 



R. SPIRALIS, Souverb. PL 55, fig. 40. 



Whitish, biigitudinally costate, with equal interstices whicli are 

 sliglitly spirally striate, base of body-whorl decussated by spiral 

 sulcations; whorls 9, slightly convex, with impressed suture; lip 

 continuous, externally thickened. Length, 5 mill. 



Neiv Caledonia. 

 R. cosTATOGRANOSA, Garrett. PI. 55, fig. 41. 



Solid, shining, ashy white, longitudinally closely, somewhat 

 obliquely flexuously, granosely ribbed, spirally closely grooved; 

 whorls 9, convex, with deep suture; lip thick, finely crenulated, 

 somewhat dilated. Length, 5 mill. 



Viti Isles. 

 R. TRIANGULARIS, Watson. PI. 54, fig. 12. 



White, with 12-13, low, distant, oblique, flexuous longitudinal 

 ribs, and much wider shallow furrows, narrowdy spirally striate 

 throughout; whorls 8, convex; pillar lip long, oblique, outer lip 

 varicose, aperture expanded below. Length, 3'75 mill. 



Cape York, N. E. Australia. 



R. GRACILIS, Garrett. PI. 55, fig. 42. 



Rather thick, somewhat shining, light brown, with rather large, 

 closely set, slightly oblique longitudinal ribs and equal interspaces, 

 ribs flexuous on lower i)art of body whorl ; whorls 9, flatly convex, 

 with margined suture; lip thick, sinuous above and below. 



Length, 3 mill. 



Viti and Society Is. 

 R. TEREBRoiDES, E. A. Smith. PI. 54, ng. 6. 



Whitish, with a median chestnut zone, with 11-12 arcuate, strong, 

 longitudinal costie, very minutely spirally striate, ribs fading below ; 

 where the strijB are stronger, whorls about 10, moderately convex; 

 lip broadly, strongly varicose. Length, 8'5 mill. 



San Christoval, Solomon Is. 

 R. LiRATA, Angas. PI. 54, fig. 10. 



Rather thin, dull milky white, with regular, thin, flexuous longi- 

 tudinal ribs, becoming obsolete below, where numerous, very fine, 

 close-set spiral stria) are visible; whorls 7, slightly convex; outer 

 lip thickened, varicose. Length, 4 mill. 



So. Audralia. 

 R. HoNOLULUENsis, Watson. PI. 54, fig. 13. 



White, with 15 subcontinuous, narrow, straight longitudinal ribs, 

 and much wider interspaces, finely, microscopically spirally striate, 



