257 



THRUSH STONES AND HELIX 

 NEMORALIS L. 



E. ADRIAN WOODRUFFE-PEACOCK, F.L.S., F.G.S. 



{Continued from page i'/4). 



The following signs require explaining. A single ' [ ' before 

 a formula, implies entire confluent lip banding, as [Iil23s42 5. 

 In this shell the fifth band v^s absent, excepting at the lip. The 

 sign ' [U ' implies the confluence of the three upper bands at the 

 lip, as [U(112)2344'25 ; a most unusual form. The sign ' [L ' 

 the confluence of the two lower bands, as [Lii23245 24 ; this 

 form is common enough. The sign ' [UL ' implies the confluence 

 of the three upper bands together, and the confluence of the 

 two lower together, with the third interspace clearly marked, 

 as [UL(1 12) 3 24(425). 



Frequently the fifth band is not the normal width below, 

 and there are many shells which can only be indicated thus : — 

 li223442[.32]. There is also a very rare shell on which the 

 bands are not in exactly the normal position. It can be in- 

 dicated thus [ol]i 1234425. The absence of a band is indicated 

 by the size of the figure, as lil 334326, where the third band was 

 not present. There is also the production of an extra band or 

 bands. Such forms may be recorded as — [li223[ili]525. 

 Much more rarely we find it thus — [Ii223[il2]425, or [li223 

 [ilili]325. Then there is the contrast, where the band has a 

 white interspace, as li22[lil]4425. All these are typical 

 specimens from this parish. 



There are two sources from which specimens may be 

 obtained for comparing the supply furnished b}^ any locality 

 with those that are destroyed by the thrushes at their anvils on 

 the spot. 



The first supply is the ' dead shells ' — perfect specimens — 

 which may be found at any place frequented by H. nemoralis L. 

 In the case of these specimens, as soon as I have taken off the 

 banding and interspacing, I crush them underfoot, so as not 

 to record them again. The second source of supply is the living 

 molluscs, which may be obtained on the ' crawl ' any clamp 

 summer evening. As one grows older and more sympathetic, 

 I suppose, one grows more and more chary of taking life need- 

 lessly. At least I find, I personally hate more and more the 

 act of destroying the molluscs to preserve their shells in the 

 county collection. So I take a vasculum out with me when I 



1909 July I. 



R 



