AQUATIC COLEOPTERA OF THE OUTER HEBRIDES 67 



List of species found cJiiefly or entirely i?t Lochs 



and Streams. 



Haliplus confinis 

 „ fiilvus 

 „ ruficollis . 

 ,, vjehnckei . 

 ,, lineatocollis 



Deronectes assimilis 

 ,, \2-pusiuIatus 



„ griseoslria/us 



Hydroporus palustris 



% 



2 



2 



5 



3 

 16 



5 



3 



8 



II 



Hydroporus discretus 

 Agahus guttahis 



,, paludosus 



,, nebulosus 



,, arcticus 



,, siiirmii 

 Ilybhts fuHgiiiosus 

 Laccobius alutaceus 



% 



2 

 2 

 2 

 2 

 16 



9 



Only a few of these are true loch species (i.e., H. confinis 

 and fulvus, D. assimilis and griseostriatus, A. nebulosus and 

 arcticus and /. fuliginosus)^ and only three are true stream 

 species (i.e., A. guttatus and paludosus and 77. discretus)^ while 

 two (//. w^//«<;/^^z and Z>. 12-pustulatus) are common to both 

 lochs and streams. The other species in the list are really 

 pond species, which find suitable conditions in the corners 

 of gravelly or sandy lochs where glyceria (mead-grass) and 

 various " non-acid " water-plants produce pond-like environ- 

 ment. Most of the species may and do occur in peaty pools, 

 but their normal habitats in peaty districts are lochs and 

 streams. In classifying species in the above list I have had 

 regard to their usual habits in Scotland, and it must be 

 remembered that many species change their habitats in 

 different districts, and that each one always occupies the 

 type of habitat which best suits it in so far as it is able to 

 force its way in, and at least many of the species are always 

 experimenting with new ground in an endeavour to find 

 something that suits them. 



Apart from these two or three communities there are no 

 very definite groups of water-beetles on the island. The 

 brackish-water community might be mentioned, but it is only 

 represented by three species, Hydroporus planus and lituratus 

 and OctJicbius bicolon. 



{To be continued) 



