336 RISSOIA. 



wider interspaces, no spiral sculpture ; whorls 4, the apex blunt, 

 the others very convex, with deep suture ; lip rather thin, without 

 a varix. Length, 2'3 mill. 



Off New England ; deep sea. 

 R. HARPA, Verrill. PI. 67, fig. 82. 



Umbilicated, thin, with numerous longitudinal plications, and no 

 spiral sculpture ; whorls 5, very convex, rapidly increasing, with 

 <leep suture ; aperture small, round, lip thin. Length, 3 mill. 



Off New England ; deep sea. 



R. MUNDA, Monts. (unfigured.) Sicily. 



Section MANZONIA, Brusina. 1870. 



R. COSTATA, Adams. PI. 63, fig. 66. 



Longitudinally, distantly costate, costse acute, elevated, nodose 

 above, spirally densely lirate ; whorls convex, round-shouldered, 

 suture deeply incised ; lip double, continuous, the internal smooth, 

 rounded, the external widely reflexed, thinly sulcate. 



Length, 3 mill. 



Europe. 



The synonyms are R. exigua, Mich., R. carinata, Phil.. Turbo 

 plicatus, Miihlf., Turbo albus, Donovan. 



R. SIBIRICA, Leche. PL 65, fig. 21. 



Turreted, elevated, brownish ; whorls 5, round-shouldered, with 

 9-10 obtuse ribs, vanishing on upper part of body whorl, below are 

 a few raised spiral lines ; lip simple, edentulous. Length, 5 mill. 



Arctic Ocean, Siberia. 

 R. MIRABILIS, Manzoni. PL 65, fig. 22. 



Scalariform, subangulate in the middle, narrowly rimate ; whorls 

 62, very convex, with deep suture, with narrow, distant longitudi- 

 nal ribs, the wider interstices closely spirally striate; yellowish 

 violet. Length, 2%5 mill. 



Canary Is. 

 R. GIBBER, Watson. PL 65, figs. 23, 24. 



Widelv umbilicated, gradate, solid, white or yellowish, sometimes 

 more or less distinctly four banded with chestnut; whorls 4]-5, 

 convex, with stout, rounded ribs, forming an undulated shoulder or 

 suture above ; umbilicus defined by a rib; lip continuous, duplicate. 



Length, 2 mill. 



Madeira and Pto. Sancto. 



