302 Capt. F. Balfour-Browne on 
requires further investigation, D. depressus is apparently only 
a loch species. 
The same type of loch suits both, and they occur upon a 
stony, gravelly, or sandy bottom, but apparently not on 
a peaty one. Some sort of vegetation seems to be necessary, 
but whereas in some lochs I found the beetles on ground 
carpeted with Lobelia dortmannt, in others this weed failed 
to produce any. The most fertile spot was usually where 
there was a patch of Myriophyllum or other weed on a stony 
bottom, but even such a place sometimes failed to produce a 
single individual. 
I examined seventeen lochs without finding either species, 
and the following is a list of these :— 
“ Upper Loch,’ Lochmaben. Dumfries, 
Clearburn L, Selkirk. 
L. Smaddie. Kirkcudbright. 
L. Lurkie. 
L. Arthur or Lotus L. Kirkcudbright. 
Knocksting L. m 
Lochenbreck L. > 
Little Dornell L. Ma 
Blates Mill L. (by Woodhall L.). Kirkeudbright. 
Dry Loch (Dungeon of Buchan). ” 
L. Dow (Craignaw). + 
Craiglee L. (top of Craiglee). e 
Long L. of Glenhead. “p 
L. Minnoch. ” 
L. Enoch. ” 
L. Arron. ” 
L. Neldricken. A 
In the case of one or two of these the peaty bottom perhaps 
made the habitat unsuitable (e. g., Little Dornell L., Blates 
Mill L., and “ Upper”? L.), while in others perhaps altitude 
excluded them (e.g., L. Enoch, 1600 ft.; L. Arron, 1400 ft. ; 
Ciaiglee L., 1700 ft. ; and L. Dow, 1300 ft.), but in the case 
of most of the others I cannot imagine why I found neither 
species, except that I was unlucky. Why, for instance, 
should L. Neldricken not have either of them, when both 
L. Valley and L. Narroch possess elegans? The Long L. of 
Glenhead is to all appearance quite as suitable for the species 
as the Round L., which contains elegans. Knocksting L. and 
L. Arthur I worked thoroughly and over very promising 
ground, and yet without result. LL. Minnoch, lying between 
Lochs Harrow and Dungeon, I worked three times, and 
examined it all round, and yet failed to find any water-beetle 
at all. Such a result is very rare in my experience ,Lochen- 
