igiS. HuGGiNS — Limnaeac of West Cork Alpine Lakes. 119 



THE LIMNAEAE OF THE ALPINE LAKES IN THE 

 GLENGARRIFF DISTRICT, WEST CORK. 



BY H. C. HUGGINS. 



During the past few years I have on several occasions 

 visited Glengarriff, West Cork ; usually in the month of 

 May ; and my time has more especially been devoted to 

 the study of the Limnaea pereger group of snails found in 

 the neighbouring mountain tarns. Several of these have 

 already been visited by Fleet-Surgeon K. H. Jones, Dr. 

 R. F. Scharff, and Messrs. A. W. Stelfox, J. N. Milne, and 

 R. A. Phillips, to all of whom I am indebted for information 

 concerning the district. In the present year, however, 

 owing to the exceptionally fine weather, I was enabled to 

 work some of the lakes in the Caha mountains, which, to 

 the best of my knowledge, have never previously been 

 visited by collectors. 



These lakes, which are situated on a mountain plateau 

 overlooking both Barley L?Jce and the Coomarkane Valley, 

 vary in altitude between 1,400 and 1,550 feet above the 

 sea level. They are all deep, with stony bottoms, and 

 contain scarcely an}^ vegetation except a few stray reeds 

 round their edges. In one only did I see some plants of 

 Potamogeton, though the bottoms were in most cases 

 partly covered with dead sheep-grass that had been blown 

 or washed in during the winter. The water in all of them 

 is decidedly peaty, and judging from the taste contains 

 traces of iron in several cases, though not to the same 

 extent as the water at Glengarriff itself, which has a rusty 

 flavour which renders it most unpleasant to strangers. 



As might be expected the shells of the L. pereger group 

 found in them were, owing to the great altitude, the presence 

 of the peat, and the depth and coldness of the water, of 

 very extreme forms ; two lakes contained specimens refer- 

 able to L. praetenuis, but mostly with very low or intorted 

 spires, and two more were inhabited b}^ L. involuta. 



The shells of the neighbourhood fall roughly into three 

 groups, a dark sluggish usually intorted one, small in size 

 and moderatety thick in shell, which includes the shells 



