NATICA (LUNATIA) CAVELLII. 695 



Butleyan and Iceman zones, where, however, it is by no means abundant. As 

 a recent shell it is widely diffused in circumpolar regions, ranging southwards 

 as far as the northern coasts of Great Britain in one direction to the New England 

 and Japanese seas in others. As a Pleistocene fossil it has been specially reported 

 from Scotland, Ireland, Scandinavia and Canada. 



Two of the specimens now figured (PI. LVI, figs. 8 and 11) belong to the 

 British Museum, where they bear the name of A. borealis, Gray, a form he and 

 some others considered distinct from A. pallida. I prefer, however, to follow 

 MM. Dautzenberg and Fischer in regarding these two, with N. groenlandica, as 

 varieties of the same species. 



Natica (Lunatia) Cavellii, sp. nov. Plate LIV, fig. 13. 



Specific Characters. — Shell large, ovate, smooth, fairly solid, not oblique ; 

 whorls 5, convex, the last about four-fifths the total length; spire elevated, 

 gradually decreasing in size towards a fine point ; suture well marked ; mouth 

 semilunar, acutely angulate above, rounded below; outer lip gently curved, 

 joining the body-whorl so as to leave most of the latter uncovered ; inner lip 

 spread over the upper part of the columella; umbilicus oval, partly open, rather 

 small but deep. 



Dimensions. — L. 36 mm. B. 26 mm. 



Distribution. — Not known living. 



Fossil : Icenian Crag : Thorpe, near Aldeburgh, Suffolk. 



Remarks. — The charming specimen given under this name was observed by 

 Mr. Bell in the Cavell Collection at Framlingham College, by the kindness of the 

 Principal of which I am permitted to figure it. At Mr. Bell's suggestion I 

 dedicate it to the memory of its discoverer, an enthusiastic collector of Crag 

 fossils. It seems a distinct form, which I am unable to refer to anything 

 hitherto described. 



Natica (Lunatia) approximata, Etheridge and Bell, MS. Plate LVI, fig. 15. 



Specific Characters. — Shell strong and solid with a thick callus, resembling in 

 form the variety Woodii of the Crag N. proxima ; the spire is shorter, however, 

 and the umbilicus is larger, partly open, deeper and not so nearly covered by the 

 inner lip as in that species. 



Dimensions. — L. 27 mm. B. 21 mm. 



Distribution. — Not recorded living. 

 Fossil : St. Erth. 



Remarks. — The specimen figured under this name is another St. Erth shell 



