THE AQUATIC COLEOPTERA OF THE NORTH EBUDES 211 



or three already referred to as being strictly northern in their 

 distribution, the Water-beetle fauna is chiefly composed of 

 species widely distributed in the British Islands. 



But although the majority of Britannic Water-beetles are 

 widely distributed, they are for the most part associated more 

 or less closely with some particular kind of habitat, and in 

 this association the elements of the fauna are merged together. 



I have already mentioned that the only kind of ground 

 worked in Skye was peat moss excepting the Broadford 

 River and one or two streams while in Eigg, except in a 

 small area close to Kildonnan, there were no collecting places 

 which were not either peaty lochs or pools, excepting the 

 streams. In both cases therefore the oxylophile associations 

 dominate the fauna, as the following lists, giving the number 

 of occurrences of every species taken in the two islands, show. 

 I have given the figures as percentages in order that they 

 may be compared in the two lists : 



SKYE. 



24 collections. 43 species. 



per cent. 

 62 



5 



H. pubescens, GyU. 



A. bipustulatus, L. } 



A. globulus, Payk. j 



H. tristis, Payk. \ 



H. gyllenhalii, Schiod. \ 



H. obscurus, Sturm. I 



Ph. melanocephalus, Ol.} 



H. viridicollis, Steph. 



H. lineatocollis, Marsh. 



G. natator, Scop. 



H. fulvus, F. 



H. morio, Dej. 



H. erythrocephalus, L. 



A. sulcatus, L. 



Ph. minutus, F. 



H. brevipalpis, Bedel. 



1 H. ruficollis, Brit. Authors) 



H. rivalis, GyU. f 



29 



2 I 



12 



ElGG. 



33 collections. 37 species. 



per cent. 



A. bipustulatus, L. . 

 H. pubescens, GyU. 

 A. globulus, Payk. 

 H. obscurus, Sturm. 

 Ph. melanocephalus, Ol. . 

 H. tristis, Payk. \ 



H. gyllenhalii, Schiod. / 

 H. viridicollis, Steph. 

 H. erythrocephalus, L. 

 A. arcticus, Payk. \ 



G. natator, Scop. 

 L. truncatellus, Thunb. ) 

 H. nigrita, F. } 



Rh. bistriatus, Forst. / 

 D. griseostriatus, DC G. . 

 H. lineatocollis, Marsh. \ 

 A. sturmii, Gyll. 

 A. sulcatus, L. j 



75 

 54 



48 

 33 



3 



27 

 24 



21 



18 



I 2 



1 The recent paper by Edwards (EMM. January 1911) points out that 

 several species have been included under the name of "ruficollis." I have not 

 kept my specimens and therefore cannot say to which species they belonged. 



