Ke7V : T7m-Bandcd Shell of Helicigona arbustoniin. 341 



The lists g-iven, though involving much repetition, illustrate 

 the ubiquity of several species and the evident concentration of 

 species in suitable localities. The favourable patches in an 

 unfavourable district are richer than equal areas in a district of 

 which every part invites attention. 



On a visit to Rose Hill, nth April 1903, Reticularia lyco- 

 perdon Bull, was observed on the willow noted above. 



NOTE ON A TWO-BANDED SHELL OF HELICIGONA 

 ARBUSTORUM FROM WENSLEYDALE. 



H. WALLIS KEW, 

 London. 



Mv friend Mr. F. W. Wilson, who has been spending a fort- 

 night in Wensleydale, has returned with a shell of Helicigona 

 arbusloriwi which has been pronounced by Mr. Taylor to be 

 the most interesting specimen of this species as yet seen by 

 him. It was found, on 5th May 1903, on the roadside near the 

 stepping-stones at Aysgarth ; and is represented in the accom- 

 panying figure, which has been drawn for me by Mr. J. Green. 

 The shell differs materially from the type in one respect only: 

 namely, in having, in addition to the band usually present, 

 another band midway between the normal one and the suture. 

 The two bands are nearly coextensive, and on a part of the 



body-whorl the additional one is as 

 distinct, or nearly as distinct, as that 

 in the normal position ; in parts it is 

 less sharply defined, but both are dis- 

 tinctly traceable side by side over the 

 greater part of the spire, the additional 

 band being lost only a little before the 

 merging of the normal band in the 

 dark colouring of the apex. In some 

 Helicoid snails the presence or absence 

 of a band, it must be admitted, is not 

 of great importance ; but in Helicigona 

 arbnstonun the occurrence of an unexpected additional band is 

 certainly of much interest. Of the thousands of specimens 

 which have been seen by Mr. Taylor from various parts of these 



1903 September i. 



Helicigona arbustorum 



V. bifasciata. Aysgarth. 



