39 46 Proceedings of the Royal Irish Academy. 



In some respects the most interesting mites found during the Survey 

 belong to the group Gamasoidea. These are small and medium-sized Aearina 

 of extremely varied habits and structure. The free-living forms may be found 

 in moist places amongst moss, in fungi, under the bark of decayed trees, &c. 

 Some peculiar forms are found only in ants' nests while others must be 

 sought for between tide-marks on the sea-shore. Many species of this group 

 live parasitieally on the bodies of other animals, with the exception of two 

 kinds found on field mice no attempt was made to collect these parasitic 

 forms. 



This group is apparently in need of a general revision, and as the species 

 pass through two or three nymphal stages during their life-history the 

 identification of one's captures is not always an easy matter. On this account 

 and partly also because there are several new species to be described, it was 

 necessary to enter into considerable detail in the following list. It is hoped 

 that the accompanying figures of the new and little-known species will leave 

 no doubt of their identity m the light of future work on the Aearina in this 

 country. 



Dr. Berlese's well-known work (1) on the Italian mites is of the greatest 

 help in this as in other groups, and the same author has recently published 

 an excellent account of the species of Gamasus (13) which greatly simplifies 

 identifications in so far as that genus is concerned. If we except Mr. Michael's 

 paper on the family Uropodidae '49) and Mr. Donisthorpe's notes on the 

 Aearina living in ants' nests very little is known of the gamasid fauna of 

 these countries, so that many of the species in the following list are new 

 British records. 



Amongst the Oribatoidea, the so-called " Beetle Mites," exactly sixty 

 species were collected including many not previously recorded from Ireland. 

 This list is doubtless incomplete, yet it is probably fairly representative of 

 the oribatid fauna of the district. These mites are very uniformly distributed 

 and may usually be found in numbers in their favourite habitats especially 

 amongst mosses. In contrast to the previous group the British species are 

 fairly well known, thanks to Mr. Michael's admirable monograph (48). Thus, 

 of the sixty kinds recorded in the following paper, representing many 

 hundreds of specimens collected in an unexplored part of the country, only 

 two species and a few varieties are not mentioned in Mr. Michael's work. 

 One of these, Orihata alpina n. sp., is not uncommon amongst moss in the 

 mountainous parts of the district, while a Xotaspis found in numbers on the 

 sea-shore at Mulranny agrees with a form recently described by Berlese under 

 the name of Oribatida venusta. 



Very few tyroglyphid mites were observed, but the occurrence of the 



