66 



THE SCOTTISH NATURALIST 



Table showing the first eight Species in the Lists 

 of five Western Islands. 



Skye 

 (North Ebudes) 



H. pubesceiis 

 A. hipitslulatiis 

 A. globulus 

 H. gyllenhalii 

 H, Iristis 

 H, obscurus 

 Ph. fuscipennis 

 H. viridicollis 



% 



62 



37 



-'9 



Clare Is. 

 (W. Mayo). 



H. pubescens 

 H. viridicollis 

 A, bipustulatus 

 Ph. fuscipennis 

 H. gyllenhalii 

 H. obscurus 

 H. tristis . 

 .1. globulus 



% 

 1 80 



67 

 57 



}44 



36 

 27 



Taking the first 8 species in the list of each island, we 

 find that all agree except in the actual order of the species, 

 with the exception that Lewis differs from the others in 

 that Rhantus bistriatus appears in the list instead of 

 Hydroporiis tristis. It is not, however, that the former 

 species has merely ousted the latter, because tristis is actually 

 at the bottom of the Lewis list. 



This little group of species, therefore, forms a dominant 

 community in all these islands, and it is essentially a peaty 

 pool community. Although individuals of some or all these 

 species may occur in lochs and streams, none of the species 

 belong to the loch or stream communities, which, although 

 not identical with one another, are closely related. Out of 

 the Lewis list the following are those which occurred chiefly 

 or entirely in the lochs or streams: — 



