172 ANNALS OF SCOTTISH NATURAL HISTORY 



may be of interest to mention that on several occasions I 

 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 i 3th, 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 larvae 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 : Diaptomus gracilzs, G. O. Sars, 

 Cyclops strenuus, Fischer, Cyclops vicinis, Uljanin, and Cyclops 



