1 66 The Lisli Naturalist. [July, 



variety were found on a ver}' bare sandy patch in the most ex- 

 posed part of the dunes close to Finner Strand, where only a few 

 plants grow sparingly among the Bent {Psamma are7iana). 

 Here they are very liable to be covered up several inches or 

 even several feet deep bj^ the shifting sands blowing in from the 

 beach with the prevailing wind. Though many of the type 

 are to be found here also, the latter are in greatest abundance 

 in the inland hollows of the dunes near the River Erne, which 

 are well turfed over, with plenty of food-plants. 



I could understand the Bundoran shells, as a whole, being 

 heavier than those from inland or north-eastern coast localities, 

 if a moist climate and freedom from severe frost are among the 

 favourable conditions necessar}^ for long life, and consequent 

 possession of a thicker shell. But why the var. liyalozonata, 

 usually a much thinner shell, should here become heavier 

 than the typical Helix 7temoralis I cannot understand, and 

 mention the fact in the hope that it maybe of interest to those 

 conchologists who are engaged in working out life-histories 

 of the land mollusca. 



It is certain that a moist, mild climate does not alwa^'s lead 

 to a thick shell, unless other conditions favourable to its 

 formation are also present. It does seem to influence the 

 size as a rule, and on Valencia Island, S.W. Kerry, the mildest 

 corner of the British Islands, this species is large, though thin 

 and light. I judge by a large number which have at different 

 times been collected there by Miss Delap. She states that 

 they do not hibernate in winter, but only retire for short 

 periods in dry or cold weather to the roots of plants. Thirty- 

 five of these large shells weigh on an average onl}^ 9*25 

 grains, the heaviest being only 1 1 grains, yet they feed prac- 

 tically all the 3^ear round, and the food supply is plentiful. 



On the Great Isle of Aran, Co. Galway, this species grows 

 to a larger size than elsewhere in Britain ; for their size 

 (many 26 by 19 mm., average 25 b}" 19 mm.) they are 

 not heavy, nine specimens collected by Mr. R. LI- Praeger, 

 now in the Dublin Museum, averaging only 13 grains. The 

 climate is like Valencia, moist and mild, and the molluscs 

 live in the deep crevices of the limestone terraces, where there 

 is good shelter and food is plentiful. These shells prove that 

 an abundance of calcareous matter present does not necessarily 



