14 THE SCOTTISH NATURALIST 



always been my desire to examine the water-beetle fauna 

 of the Outer Hebrides with a view to making further observa- 

 tions on the distribution of species, and in the hope that a 

 more extended knowledge of such distribution might enable 

 me to draw some conclusions as to the origin of these island 

 faunas. 



During last July, accompanied by a few friends interested 

 in other zoological groups, I stayed three weeks in the island 

 of Lewis, spending a fortnight of that time at Barvas, a desert 

 spot on the western seaboard, 12 miles from Stornoway, 

 During that fortnight, with the aid of a bicycle on some of 

 the worst roads I have ever ridden, I was able to work the 

 northern part of the island fairly thoroughly. The last week of 

 my time I spent at Tarbert, Harris, where, with the exception 

 of one short expedition on my bicycle, I worked only the 

 ground I was able to reach on foot. 



The northern part of the island is very different from the 

 Tarbert district. It consists of undulating country covered 

 far and wide with a layer of peat, and, for the most part, the 

 peat, although to a large extent excoriated, covers the under- 

 lying rock so that patches of bare rock are comparatively 

 few and far between. In this northern part there are only 

 three outstanding hills : Muirnag (808 ft.), between Stornoway 

 and the Butt of Lewis; Mholach and Ben Barvas (955 ft), 

 north-west of Stornoway, and about half-way across the 

 island ; and Ben Bragor (857 ft.), nearly in the same line, 

 but close to the western seaboard. From any of these hills — 

 I only climbed the last-mentioned one — an extensive view 

 of the surrounding country is to be seen. " For a distance 

 of 32 miles northward of Loch Erisort" (a sea loch on the 

 eastern coast projecting some miles due west into the island) 

 " the island does not rise above 900 ft.,^ and most of it is 



^ The Ordnance map gives Mholach as 955 ft., but Bartholomew's 

 J-inch map only marks one height on this group of hills, which is there 

 called Beinn Bharabhais, the height being 874 ft. This corresponds to 

 the top, called Beinn a' Sgridhe in the Ordnance map. I thought that 

 possibly Dr Lewis had taken his heights off Bartholomew's map, but I 

 see in that map that Muirnag's height (there called ' Monach ') is 1807 

 ft., which is obviously a mistake. Presumably the heights given in the 

 Ordnance map are correct. 



