29 8 Proceedings of the Royal Irish Academy. 



The only species worth mentioning from the Curraun district is Octhebius 

 punctatus. I succeeded, after much labour, in finding at Mulranny two or 

 three specimens of this, one of the only two salt-marsh species in the West 

 Mayo list. I spent a very short time in this locality, and took only twenty- 

 three species. The Westport district, where I took forty-two species, may 

 be passed over without comment. 



The Louisburgh district produced sixty-nine species and was therefore the 

 richest part of the whole area. This was largely due to variety of habitat, 

 for instance, the numerous pools in the Boulder-clay along the road to Doo 

 Lough, in which many helophile species occurred, and the sandy loughs along 

 the coast where, besides helophiles, one or two lake species find a home. The 

 halophile fauna was remarkable for its absence, although several places 

 seemed to be specially suitable for it. 



The occurrence of Agabus congener in this district has already been referred 

 to and otherwise only three species need be mentioned. Hclophorus granulans 

 was found in hundreds in the flooded grassy ground by the Bunowen Eiver in 

 the spring. A single specimen had occurred in a shallow grassy ditch in the 

 neighbourhood in the previous July, perhaps a survivor of the army of the 

 previous spring. 



Hydraena testacea, previously only taken once in Ireland, at Thomastown 

 (Kilkenny), 1 occurred very sparingly in one grassy ditch near Louisburgh. 

 This species is easily passed over and is, I fancy, chiefly a spring insect. It 

 occurs mostly in the southern counties of England but has once been recorded 

 from Scotland (Kirkcudbright) and I took it in the Isle of Man. 



From this district A. W. Stelfox brought me a single specimen of Agabus 

 unguicularis, a species I was unable to find. An interesting point about its 

 distribution in Ireland is its apparent absence from the south-eastern counties. 

 It occurs in the north and west as far south as North Kerry but there is no 

 record for Leinster or for the eastern part of Munster. 



The following list includes all the species taken on the mainland of West 

 Mayo. After each species I have indicated the districts in which it has 

 occurred and, unless I have taken the species myself, I have given the 

 initials of the collector. In a case where I have received a species or one has 

 been recorded from a district in which I myself have taken it I have only 

 given my own record, as in the case of the Clare and Achill Island lists. 



1 Johnson and Halbert's " List.' 



