29 1 Proceedings of the Royal Irish Academy. 



The following species occurred chiefly in this area : — 



Haliplus ruflcollis 1 8 out of 12 occurrences in the island. 



H. lineatocollis. 4 out of 6 „ „ „ 



Hydroporus palustris. 4 out of 6 „ „ „ 



Helophorus brevipalpis. 8 out of 13 „ „ „ 



When plants occur only on a cultivated area on an island, any question 

 as to their origin is swept aside by the assumption that they have been 

 brought in by man, but in the case of water-beetles such an assumption is 

 untenable. None of the above-mentioned species are entirely absent from 

 peaty ground but every species is predominantly helophile as opposed to 

 oxylophile. We therefore have here the same problem as presented itself in 

 the case of the island of Eigg. 2 Is the helophile fauna a remnant from a 

 pre-peat age or is it a new fauna which has drifted into the island in recent 

 times ? 



It is to be noted that of the four species which occurred in Eigg, three 

 are among the Clare Island helophiles also, viz. : H. fuscipes, H. brevipalpis 

 and C. orbiculare while the fourth Eigg species is normally found in moving 

 water and not in stagnant pools, as is also A. pialudosus in the above list ; it 

 occurred in some marshy ground with drainage water running through it. 



There is however nothing distinctive about this helophile fauna; a few 

 of the species are southern, e.g. II. lineatocollis, H. planus, D. punctulatus, and 

 L. ahdaceus, while the rest have a wide continental distribution, some of them 

 throughout most of the palaearctic region, e.g. H. brevipalpis and O.pijgmaeus, 

 and some even reaching North America, e.g. /. fuliginosus and H. fuscipes. 

 There seems to be nothing therefore to assist in determining the age of the 

 group so that it merely becomes a question as to the time of arrival of the 

 general fauna, which will be referred to later on. 



Forty-five collections were made on Clare Island and forty-seven species 

 were found and in the following list I have given, after each species, the 

 number of collections in which it occurred. 



1 [All the specimens which I kept — only a few — and all those which were sent me are M. ritfi- 

 colhs, De G. Possibly however some of the related species occurred. Vide Edwards, J.: "A 

 Revision of the British species of Haliplus, Latr." EMM., xxii, Jan., 1911-1 



2 F. Balfouk Browne : " Aquatic Coleoptera of the North Ebudes." Ann. Scott. Nat. History, 

 July and October, 1911. 



