STANDEN: TF.RRESTRIAL MOLLUSCA OF SILVERDALE DISTRICT. 327 



insects were spoilt by the slime on the net. Alongside a wood at 

 Windy Scout, near Warton Crag, it was so plentiful on everything, 

 that sometimes I had quite a teacupful of shells in the net at one 

 time, and had to empty it after every few strokes. On one occasion 

 when there had been rain overnight, the wet limestone roads were 

 dotted over with this species, evidently attempting to cross, and one 

 could not walk near the roadside without crunching the shells under- 

 foot. I have an idea that thrushes, hereabouts at anyrate, do not eat 

 H. ri/fescens, or surely they would soon thin its numbers. There are 

 plenty of thrushes about, and "thrush-stones" abound, but I only saw 

 broken shells of II. aspersa around them. Of course, this is not 

 proof positive, as a thrush would not require a stone to break H. 

 riifescens, but could easily crush such a fragile shell with its beak ; 

 still, seeing that the birds go to the trouble of breaking the larger 

 shell, it denotes a marked preference for it over the smaller species 

 crawling about conspicuously in the immediate vicinity of the "thrush- 

 stones. Mice, however, do a considerable amount of destruction 

 amongst this and other small species, and also If. 7iemoralis and 

 Helicigona arbustoruiii, judging from the numbers of gnawed shells to 

 be found under stones in this neighbourhood. 



Patches of grass on the sea-cliffs, clumps of tall bracken, or the 

 thick growth of ivy spreading over the ground in the woodlands, 

 when swept yielded enormous quantities of very young Sphyradmm 

 edentuljwi, with from three to four whorls. The adult shells of this 

 species have a habit of climbing into the blackberry bushes, and 

 ensconcing themselves at the base of a prickle, but their attachment 

 is so slight that it is difficult to secure them when in this position, 

 owing to their dropping when the bushes are shaken. Vertigo pygmcea 

 is fond of climbing up the tall grasses — known locally as "sedges " — 

 growing in damp places, and in a ditch near Warton Crag many 

 specimens occurred at about three feet from the ground, perched in 

 the little cup-like glumes of the grass seeds, and at the junction of 

 the leaves with the stem. On some of the ancient moss-covered wall 

 fences, probably dating back to the time of the Enclosure Act, which 

 came into force in this neighbourhood during the reign of George III, 

 Vertigo alpestris and V. pusilla abound. Both species are especially 

 common in the vicinity of Haweswater Tarn, and invariably occur just 

 under the topmost stones. V. siibstriata is not so partial to the tops 

 of the walls as the above-named species, but mostly lives at the grassy 

 base, and is common also underneath mossy stones and logs in the 

 woods. This district would appear to be the great metropolis, in 

 Lancashire, for these three interesting little species, until of late years 

 considered such rarities, for the older conchologists do not seem to 

 have had the knack of discovering them in any quantity. 



