35 2 Proceedings of the Royal Irish Academy. 



found fairly commonly there. My own work in the district included four 

 days spent on the island in July, 1909, followed by a longer stay at 

 Mulranny ; while in September, 1911, with Leenane as headquarters, the 

 district between Clew Bay and Killary Harbour was explored. 



As may be seen from the list which follows, in which 108 species are 

 recorded, the spiders of Clare Island do not differ materially from those of 

 the adjoining mainland. There are a few species which haye been found in 

 the one district that haye not so far occurred in the other ; but so far as I 

 know there is no particular reason why they should not do so. 



The complete area under survey is the western half of Co. Mayo, known 

 in Mr. B. LI. Praeger's scheme by the initials WE or the number 27. 



In the list, I have put after the names of the species the letter C, which 

 indicates that the species occurs on Clare Island, or M, which means that it 

 has been found on the mainland of Co. Mayo, or both letters, if it is common 

 to the whole area, I give also a few notes on some of the rarer species, three 

 of which are new to the Irish list. 



A small collection was also sent me by Mr. B, LI. Praeger and Mr. E. Welch 

 from the Bills rocks, which lie some nine miles to the west of Clare Island, 

 and which deserves special note. It contained the four following species : — 

 Segestria seiwculata L., Lephthyplmntus tenuis Bl., Pedanostcthus lividus Bl., 

 and Zycosa ruricola de Geer. Of these, there was a single specimen only of 

 the second and third, while there were several of each of the other two. A 

 wild and exposed spot such as the Bills rocks is the natural habitat of Segestria 

 senoculata, a very hardy species, and one which lives in crannies of the rocks 

 and would thus escape the fury of the Atlantic storms ; but it is certainly 

 remarkable to find that a delicate little spider like Zephthyphantes tenuis 

 should be able to maintain itself on such a spot. 



Professor Carpenter informs me that he received several years ago the 

 following species from Inishbofin : — Segestria senoculata, Xysticus cristatus, 

 Tetragnatha externa, Araneus cornutus, Lyeosa ruricola, Pirata piraticus, and 

 Pardosa nigriceps. 



I wish to offer my sincere thanks to Dr. A Eandell-Jackson for the 

 great help he has given' me in identifying the species that were unknown to 

 me, and also in confirming the identification of many others among the 

 less common kinds. I have also to thank Dr. E. F. Scharff, Professor G. H. 

 Carpenter, Mr. E. Welch, Mr, Kevin Foster, Mr. H. Wallis Kew, Mr. P. H. 

 Grimshaw, and Mr. E, LI. Praeger for collections sent me from the island and 

 various other parts of the district. I have also made use of Professor 

 Carpenter's records, in his " List of the Spiders of Ireland," 1 of captures on 

 Achill Island. 



1 i'roc. K.I. Acad., ser. 3, vol. v, pp. 128-210. 1898. 



