78 The Irish Naturalist. [March, 



mainly I think, after a smart rain-shower in dry weather, that 

 has given rise to the curious belief among peasants in the 

 South-east of England and other places that it "rains snails" 

 occasionally. At Ballycastle ** snail showers " (!) of those two 

 species w^ere not uncommon before the advent of golfers on 

 the warren, whosebig feet have tramped thelives outof myriads, 

 and reduced their numbers considerabl}^ At Portrush, 

 Portsalon, Great Island of Aran, and other places I have 

 noticed Helix e7'icetorum appearing suddenly in the same way, 

 and some other species as well, in favourable spots. 



These slopes at Whitepark are much exposed, and in windy 

 weather man}' of the shells are blown off their food-plants, or 

 swept off them and the short grassy sward by heavy rain, and 

 carried down to the desert below, where the drifting about 

 in the sand soon ends the life of the majority, the animal 

 forming acceptable food to the beetles and other small 

 scavengers of the dunes, which soon clean the shells out. 

 Many shells of course which die in the ordinary way get 

 carried down b}^ the same agencies, which also destroy old 

 dunes, these latter furnish many shells from former ** pockets," 

 long since covered up by shifting sands, to swell the bulk of 

 later ones, which might under very favourable conditions 

 become large deposits, even though many shells are broken 

 or ground to powder in the proceSvS. 



Nice sections in old dunes now altering may be noticed at 

 Portstewart, Castlerock, Whitepark, and Bundoran, «&c. (at 

 the latter some of the dunes are over loo feet high) ; little 

 bands of shells may be seen here and there, the shells falling 

 out as the wind planes the section a stage further in. 



I believe it is from these old layers that the fine scalariform 

 and reversed or sinistral Helix nevwralis are obtained at 

 Bundoran on the Finner sand-hills, as no collector has 

 hitherto found a living colony there ; the shells too look very 

 much sand-planed, as with long drifting. 



While the smaller Whitepark " pockets " so far yield more 

 species, the largest I have seen are on the Portstewart dunes 

 near the Bann, and contain also fresh-water species, though 

 in small quantities, evidently derived from the flood debris of 

 the Bann, a matted mass of vegetable matter with land and 

 fresh-water shells, beetles, &c., swept from its banks and 

 shallow margins by the river after heavy rains and thrown up 



