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 

 deep 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. PL 63, fig. 66. 



Longitudinally, distantly costate, costaB 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 silicate. 



Length, 3 mill. 



Europe. 



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

 plicatus, Miihlf., Turbo albus, Donovan. 



R. SIBIRICA, Leche. PI. 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. PI. 65, fig. 22. 



Scalariform, subangulate in the middle, narrowly rimate ; whorls 

 6-}, 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 42-5, 

 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. 



