BOYCOTT : CECOLOGICAL NOTES. 171 



A. W. Stelfox tells me that he has never found Balea on the ground 

 in Ireland, and diligent search round our local elm trees at all 

 seasons of the year has failed to produce a single specimen on the 

 ground. This is the more remarkable, because two at least of its 

 most favoured haunts (walls, apple-trees, possibly also elms) are of 

 human origin and the trees are in any case relatively temporary 

 homes, with a duration of perhaps 100-150 years on the average ; 

 in many parts of England it cannot live in crannied rocks because 

 there are none. 



It appears clear, therefore, that it must sometimes live on, or 

 at any rate move over, the ground. But it is equally clear that 

 the ground is a place which it does not like. I take this interpreta- 

 tion of its habits and call it fjeo'pJiobic, because it seems much more 

 likely that they are due to an effort to "avoid evils on the ground 

 rather than to attain delights in high places. Dryness and the 

 absence of earth cannot per se be very attractive to a snail. 



Pijramidula rupestris, which lives on rocks, quarry faces (of 

 human origin), and such-like places, exposed to the weather in an 

 extraordinary way, should also be classed as geophobic ; probably 

 too Pupa umhilicata} In Herefordshire the most favoured haunts 

 of this last species are ivy-covered stone walls, which harbour 

 ifc in abundance with the greatest regularity, and the little ledges 

 with thin grass and dead leaves which generally abound on the 

 vertical faces of the limestone quarries. It is found also on trees, 

 among stones and rubbish — in small numbers indeed almost any- 

 where — but it is evidently in these two artificial habitats that it 

 finds the most favourable conditions. Dryness, absence of other 

 animals, and remoteness from the ground seem again to be the 

 essential features. On the chalk of Wilts and Hants, where the 

 soil is drier and the rainfall less, it shows no preference for walls 

 and lives, sometimes in beechwoods abundantly, on the ground. 

 This suggests that a liking for lime has something to do with its 

 habits in Herefordshire, and the fact that it is much less common 

 and abundant in the dry east than in the damp west of England 

 may also be incompatible with the view which I suggest. Vallonia 

 costata and, with more probability. Vertigo alpestris ^ may also be 

 geophobes. 



It must be more than a coincidence that B. perversa,^ P. umhilicata, 

 and P. rupestris are viviparous. The only other English land snail 

 agreed to have this mode of reproduction, so obviously protective 



1 Trans. Herts Nat. Hist. Soc, xvii, 238. 



2 R. Standen, Journ. Conch., xi, 327 ; J. S. Dean and C. E. Y. Kendall, 

 ib., xiL 210. 



' This seems certain (A. E. Craven, Journ. Conch., vi, 421 ; T. Rogers, 

 ib., vii, 40 ; Ci M. Steenberg, " Anatomie des Clausilies danoises," 1914, p. 40 ; 

 personal observations) despite the circumstantial accoimt of eggs and their 

 hatching given by Moquin-Tandon (" Histoire," ii. 351), and reproduced by 

 Jeffreys (" Brit. Conch.," i, 274). 



