362 RISSOIA. 



R. TARSODES, Watson. PL 67, fig. 77. 



Scarcely rimate, white, with about 20 narrow ribs, fading below 

 the periphery, clathrate by distant, spiral lirse, extending feebly 

 over the base ; whorls 5, convex, slightly shouldered, with deep 

 suture; lip feebly varicose. Length, 1/87 mill. 



Off Fayal, Azores; 450-500 fms. 



R. DIDYMA, Watson. PL 67, fig. 76. 



Scarcely rimate, strong, dull yellowish, with about 12 strong, 

 narrow, distant longitudinal ribs, fading below the periphery, nodu- 

 lously clathrate by equal, distant, spiral ribs, with three smaller, 

 closer ones on the base ; whorls 5], with deep suture; lip very thick, 

 subduplicate. Length, 2'15 mill. 



Near Culebra and St. Thomas, W. I. ; 390 fms. 



R. CIMICOIDES, Forbes. PL 65, fig. 27. 



Solid, opaque, yellowish or fulvous brown, sometimes bifasciate, 

 with rather broad longitudinal riblets, vanishing below, crossed by 

 spiral unduluting lirse, forming intersectional nodules; whorls 7-8, 

 somewhat flattened in the middle, the last dilated, suture channeled; 

 lip varicose. Length, 5'5 mill. 



Mediterranean Sea to Norway. 



It is R. sculpta, Forbes and Hanley, R. intermedia, Aradas. 



R. GERGONIA, Chiereg. PL 65, fig. 10. 



Solid, fulvous, strongly tuberculated by longitudinal ribs crossed 

 by spiral lirse, the subsutural series strongest and largest ; whorls 6, 

 slightly convex, suture not deep ; lip plicate within, externally vari- 

 cose. Length, 3'5 mill. 



Mediterranean Sea. 



R. Marice, Bucq. Dautz. Doll, (not Orb.), is a synonym. 



R. LUSCINIJE, Watson. PL 67, fig. 79. 



Imperforate, glossv, yellowish white, with about 16, low, rounded, 

 distant ribs, nearly obsolete on the last whorl, crossed by rather 

 closer, equally strong, revolving ribs, which continue to the base, 

 intersections slightly nodulous; whorls 5, convex, with deep suture; 

 lip varicose. Length, 2*25 mill. 



Nightingale IsL, of Tristan da Cunha-, 100 to 150 fms. 



R. SUBCRENULATA, Schwartz. PL 64, fig. 2. 



Rather solid, shining, subhyaline, white, with strong longitudinal 

 ribs and scarcely smaller spiral lirse, the intersections distinctly 



