172 ANNALS OF SCOTTISH NATURAL HISTORY 
may be of interest to mention that on several occasions lie 
have thoroughly examined the Edinburgh water in the same 
way as was done at Rothesay in 1887, and have rarely been 
rewarded with even a single specimen of “beasts” of any 
kind: the water supplied for domestic purposes to Edinburgh 
appears to be so carefully and efficiently filtered that 
organisms of any kind rarely find their way to the water-tap. 
The following reference to an example of an opposite 
kind to those given above may be of interest. In June 1889 
an examination was made of Loch Coulter: it is from this 
loch that the water-supply for the famous Howietoun fish- 
hatcheries and nurseries is obtained. The weather was mild 
and warm at the time the loch was examined, and the water 
was teeming with entomostraca. Being desirous to find out 
if any of the little creatures were being carried down by the 
stream which flows out of the loch and supplies the hatcheries 
and nurseries, a tow-net was fixed in the bed of the stream 
a short distance up from where the water is led off into the 
nurseries, and so arranged that most of the water in the 
stream had to pass through it. The net was placed in 
position at 7.15 P.M. on the 13th, and removed at 8.15 A.M. 
next day. Although the water had thus been allowed to 
flow continuously through the tow-net for thirteen hours, only 
a few Cyclops, Gammarus, Ostracods, and the larve of insects 
were captured. With the exception of the few Cyclops, which 
were the only organisms that were likely to have been brought 
down from the loch, all the specimens captured appeared to - 
be stragglers from places in the vicinity of the position where 
the net had been fixed. (See “ Eighth Annual Report of the 
Fishery Board for Scotland,” p. 338, 1890.) 
I may mention that Mr. Tullis very kindly sent me two 
bottles containing water-fleas from the River Leven: one 
was a sample of those first obtained by him from the strainers 
in the early part of the year; the other contained several 
living specimens recently collected. Though the specimens 
in the first bottle were somewhat decomposed owing to the 
length of time since they had been gathered, I yet had no 
difficulty in identifying most of the species. The following 
are the names of them :—Dzaptomus gracilis, G. O. Sars, 
Cyclops strenuus, Fischer, Cyclops vicinis, Uljanin, and Cyclops 
