29 6 Proceedings of the Royal Irish Academy. 



typical peat-pool fauna of Clare Island is identical with that of these other 

 three islands. 



Only three species in the Clare Island list call for any remark. H. celatus 

 occurred at 700 feet on Croaghmore in a small pool in a trickling stream, the 

 typical habitat of the species. The Irish records for this species are few. It 

 was tirst taken by Mr. J. X. Milne at Downhill (Deny) and recorded by the 

 late C. W. Buckle. 1 A single specimen was taken by Eev. W. F. Johnson in 

 1907 in Co. Armagh, and I have since that taken the species in Mid Cork (1) 

 August 1907 ; in Down, 1908 ; in Leitrini and Clare Island, 1909 and in 

 Co. Antrim, August 1911. It is a mountain species by choice, and therefore 

 in Ireland its distribution is marginal but it is, I think, much less rare than 

 the records indicate. 



P. nigroaeneus was common in a few peat-holes at various parts of the 

 island up to about 700 feet above sea-level. It occurred also on Achill and 

 on the mainland but did not seem to be so common as in the pools on Clare 

 Island. 



0. lejolisii I found on both sides of Clare Island, east and west, and it 

 was common. On the east side I found it at once quite near the hotel and 

 just above high-water niark. At the west end I searched for a considerable 

 time before I discovered it ; here it was in pools rather more than 100 feet 

 above the sea, which gives some idea of the delicacy of the balance between 

 this insect and its environment. It always occurs along a narrow belt 

 sufficiently close to the sea to be certain of an intermittent but fairly frequent 

 supply of sea-water in the form of spray and yet far enough above the high- 

 tide mark to ensure occasional flushings of the pools with fresh water. The 

 height above sea-level at which it occurs on the western side of the island as 

 compared with the eastern side indicates the comparative wave-motion on the 

 two sides. 



Achill Island produced much the same kinds of habitat as Clare Island 

 but I worked the former much less thoroughly than the latter and found only 

 thirty-eight species. Only nine collections were made during each visit and 

 on the second occasion I did not work any of the same places as on the first 

 so that a comparison of the results is not quite reliable, although perhaps it 

 indicates the relative abundance of species in July and March. In the former 

 month the average number of species per collection was eleven or twelve while 

 in the latter it was only five or six. 



Apart from B. griseo-striatv.s already referred to, the only species worthy 



1 "Beetles collected in Lough Foyle District, Counties Donegal and Derry." Irish Xat., 

 January, laOO, pp. 2-11. 



