658 PLIOCENE MOLLUSC A. 



Remarks. — MM. Dautzenberg and Fischer have revived the disused name 

 rudissivia, Bean, for some varietal forms of the present group of which they have 

 represented a number, varying in size and spiral ornamentation. M. Dautzenberg 

 has kindly sent me a recent specimen which he considers typical of this shell and 

 has allowed me to figure it. I have occasionally met with examples in the Icenian 

 Crag at Bramerton corresponding closely with it, approaching the northern var. 

 groenlandica, but differing distinctly from the general character of the other Crag 

 varieties. 



The shells for which Bean's name riidissima was originally used were found 

 abundantly on rocks near high- water mark at Scarborough. That author specially 

 distinguishes them from the typical L. rudis by their raised spiral markings and 

 their patulous mouth and body-whorl. 



Var. groenlandica (Menke), Moller. Plate LIII, figs. 12, 13. 



1842. Littorina grcenlandica, Moller, Intl. Moll. Grcenl., p. 9. 



18-46. Littorina groenlandica, Philippi, Abbild., p. 103, pi. i, figs. 11 — 13. 



1871. Littorina groenlandica, Morch, Geol. Mag. [1], vol. viii, p. 396. 



1878. Littorina rudit, var. groenlandica, G. 0. Sars, Moll. Reg. arct. Norv., p. 165, pi. ix, fig. 10. 



1898. Littorina rudis, var. groenlandica, Posselt, Medd. om Grronl., vol. xxiii, p. 231. 



1908. Littorina sa.vatilis, var. groenlandica, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. iv. 



p. 62, pi. ex, figs. 19, 20. 

 1912. Littorina sa.vatilis, var. groenlandica, Dautzenberg et Fischer, Camp. Scient., Prince de Monaco, 



vol. xxxvii (Mollusques), p. 198, pi. x, figs. 21, 28. 

 1917. Littorina rudis, var. groenlandica, Schlesch, Hull Mas. publications, no. 110, p. 280. 



Varietal Characters. — Shell ovate, tumid, generally larger than the typical 

 L. rinJis, fairly solid; whorls 5 or 0, decidedly convex, the last much the largest ; 

 suture deep, subcanaliculate ; spire short, rapidly diminishing in size towards an 

 acute apex; ornamented by spiral ridges, more or less prominent and distinct ; 

 mouth large, oval, patulous, somewhat expanded; outer lip thin. 



Dimensions. — L. 15 — 20 mm. B. 12—15 mm. 



Distribution. — Recent: northern coasts of Norway, Finmark, Lofoten Islands, 

 Iceland, Greenland. 



Fossil: Icenian Crag : Bramerton. 



Remarks. — Of this decidedly Arctic species, found as fossil at present in the 

 Icenian Crag only, there are one or two specimens from Bramerton in the Norwich 

 Museum which correspond very closely with some recent shells I have received 

 from Finmark. Prof. Gr. O. Sars states that they sometimes reach 20 mm. in 

 length; the Crag forms, however, are somewhat smaller. It seems a distinct form 

 which may be easily recognised by its general appearance and its rounded and 

 ventricose whorls. 



