LITTORINA RUDIS. 655 



Var. saxatilis (Olivi). 



1792. Turbo saxatilis, Olivi, Zool. Adr., p. 172, pi. v, figs. 3 a — 3 d. 



1841. Littorina saxatilis, Johnston, Proc. Berwicksh. Nat. Club, vol. i, p. 268. 



1853. Littorina saxatilis, Forbes and Hanley, Brit. Moll., vol. iii, p. 43, pi. lxxxvi, figs. 4, 5. 



1859. Littorina saxatilis, G-. B. Sowerby, 111. Ind. Brit, Shells, pi. xii, fig. 19. 



1867. Littorina rudis, var. saxatilis, Jeffreys, Brit, Conch., vol. iii, p. 365. 



1892. Littorina saxatilis, Locard, Coq. mar. Cotes de France, p. 189. 



1908. Littorina saxatilis, Kobelt, Icon, schalentrag. europ. Meeresconch., vol. iv, p. 57, pi. cxii, 



figs. 1 — 4. 

 1912. Littorina saxatilis, Dautzenberg et Fischer, Camp. Scient,, Prince de Monaco, vol. xxxvii 



(Mollusques), p. 192, pi. ix, figs. 1—6. 



I arietal Characters. — Shell minute, smooth or spirally ridged, smaller than the 

 typical L. rudis, nearly globular ; mouth sub-orbicular ; outer lip arcuated making 

 nearly a right angle with the body whorl ; colour greyish with a white base. 



Dimensions. — L. 4 — 5 mm. B. 3'5— 4 mm. 



Distribution. — Recent : British and French coasts. Adriatic (Dautzenberg). 



Fossil: Pleistocene: Bridlington, Cranstal (Isle of Man), Selsey. 



Remarks. — There seems to be considerable difference of opinion as to the correct 

 identification of the Turbo saxatilis of Olivi. The Rev. Dr. A. H. Cooke and Mr. J. R. 

 Le B. Tomlin have been kind enough to examine some minute specimens of Littorina 

 from the Bramerton Crag which I thought might be referred to it but they express 

 a decided opinion that this is a mistake. They consider that this form is "always 

 smooth and not ribbed at all." On the other hand I have received others from 

 Venice through M. Dautzenberg which he considers Olivi's typical shell. They 

 are distinctly ridged, corresponding closely with recent examples under this name 

 in the Holmes collection at the Norwich Castle Museum. Those represented by 

 Forbes and Hanley, Gr. B. Sowerby and Kobelt, moreover, are also spirally orna- 

 mented. Jeffreys, who unfortunately did not always figure his varietal forms, 

 says that the var. saxatilis, though usually smooth, is sometimes finely ribbed. I have 

 no evidence that Olivi's shell occurs in the English Crag, but Mr. Bell has found it 

 in Mr. Headley's collection of fossils from Bridlington. AVhether this group of 

 molluscs should bear the varietal name of rudis or of saxatilis seems to me com- 

 paratively unimportant. The point is that the rudis of the Crag and the saxatilis 

 of Bridlington are different, the one being characteristically Pliocene, the other 

 Pleistocene. 



Var. laevis, Jeffreys. Plate LIII, figs. 3, 4. 



1865. Littorina rudis, var. Ixvis, Jeffreys, Brit, Conch., vol. iii, p. 365. 



1901. Littorina rudis, var. Levis, Conch. Soc. List, Journ of Conch., vol. x, p. 17. 



