RIMULA. 451 



Shell ovate, conical, elevated, surface with radiating 

 ribs; apex entire, sub-spiral, slightly recurved posteriorly; 

 perforation linear, between the apex and front edge, vaulted 

 over internally by a shelly plate ; aperture oval, expanded, 

 the margin entire. 



Syn. Sipho, Broun, not Klein. Diadora, Gray. Ri- 

 mula, Loven, not Defrance. Puncturella, Lowe. 



Ex. C. Noachina, Litinceus, pi. 51, fig. 7, 7, a, 7, b. 

 Shell, C. Noachina, fig. 7, c, 7, d. 



The range of cirrhi on the sides of the foot in this 

 genus is interrupted, behind, on each side; the species 

 inhabit the British Islands, Greenland, Norway, Boreal 

 America, and Tierra del Fuego. 



Species of Cemoria. 



cognata, Gould. galeata, Gould. 



conica, UOrb. Noachina, Linn. 



cucullata, Gould. priuceps, Gould. 

 fastigiata, A. Adams. 



Genus RT.MULA, Defrance. 



Shell ovate, depressly-conical, thin, surface cancellated; 

 apex recurved towards the hinder extremity, entire ; per- 

 foration elongate, fissure-like, between the vertex and the 

 front edge. 



Syn. Rimularia, Defrance. Rimulus, D'Orb. Ditre- 

 maria, D'Orh. 



Ex. R. exquisita, A. Adams, pi. 51, fig. 8. 



This genus was founded on some fossil species of the 

 Bath Oolite ; several recent species, however, have been 

 discovered by Mr. Cuming among the Islands of the 



