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WHITE VARIETIES OF HELICELLA GIGAXII. 



By CHARLES OLDHAM. 



(Read before the Society, December 9th, 1914). 



In speaking of Helicella gigaxii I assume that the shell which Mr. 

 A. W. Stelfox (Proc. Mai. Soc, vol. x., p. 39) identifies with Helicella 

 heripensis (Mabille) is really referable to the Helix gigaxii of 

 Charpentier. This species, whatever view systematists may ultimately 

 take of its identity, is abundant on the Chilterns on the borders of 

 Hertfordshire and Buckinghamshire, and during the autumn of 1914 

 I collected several albine specimens in that district. Most of them 

 had translucent bands or streaks, but at Little Tring I took half-a- 

 dozen which lacked shell-markings. These albine shells indeed 

 corresponded respectively with the typical form and with forms 

 devoid of markings such as the vars. hiiescens a.r\6. albicans of Kendall, 

 but were entirely without pigment. The pigmented forms are 

 separated according to the presence or absence of bands or other 

 markings, and the albine forms may with propriety be distinguished 

 on the same grounds. I propose the name alba for the immaculate, 

 and hyalozonata for the banded or streaked form, and append a brief 

 description of each. 



var. alba — Shell pure white, apex translucent, markings absent or 

 only represented by a few minute and irregularly scattered translucent 

 spots representing the minute coloured specks which are often 

 present in pigmented shells. Locality, Little Tring, Herts. 



var. hyalozonata — Shell pure white, apex and shell markings, 

 whether bands, mottlings or transverse streaks, translucent. Locali- 

 ties, Wendover, Bucks.; Little Tring, canal-bank near Tring station, 

 and Hudnall Common, Herts. 



Reversed Helix aspersa in Carnarvonshire. —I found a living adult ex- 

 ample of the monst. sinisirum of Helix aspersa on the cliffs at Forth Oer near 

 Aberdaron on October 2nd, 1914. Although the occurrence of such abnormalities 

 may have no distributional significance, it is perhaps well that they should be 

 recorded. — Chas. Oldham {Read before the Society, Dec. 9th, 1914). 



