338 Part III. — Eighth Annual Report 



loch, the level of the water, we were informed, was about 4 feet higher 

 than it usually is at that season, and consequently the overflow was 

 greater than usual. In order, therefore, to ascertain whether Entomos- 

 traca were being carried down the stream, a tow-net was fixed in mid- 

 channel a short distance up from where the water is led off into the 

 rearing ponds at Howietoun; and, further, the net was so arranged that 

 a large proportion of the water would pass through it, and thus give the 

 experiment a fair trial. The net was fixed in position at 7.15 p.m. of 

 the 13th, and removed about 8.15 a.m. of the 14th. Thus the water was 

 allowed to pass through the net for fully 13 hours, but the result was 

 not what had been expected, only a few Cyclops, Gammarus, Ostracods, 

 and the larvae of insects being captured. There was also a small quantity 

 of mud in the net. The Gammarus^ Ostracods, and insect larvae were very 

 likely carried into the net from some place in the vicinity of where the 

 net was fixed, while the few Cyclops were probably the only organisms 

 carried down from the loch. It was thus fairly evident that though 

 Entomostraca were abundant in Loch Coulter, very few found their way 

 down the stream. 



On the stones in the burn a few of the common Limncea peregra were 

 observed, and a somewhat rare Ostracod — Candona acuminata — was 

 obtained in a marshy place at the side, otherwise nothing requiring special 

 notice was observed between the Hatching House and the ponds. In the 

 ponds nothing of special interest was observed except that in one of them 

 Candona acuminata was again noticed, and Cypria exculpta in another, 

 in the ' Botanical pond ' Conferva was moderately common. 



The following are the species of Mollusca and Crustacea observed in 

 this section : — 



MOLLUSCA. 



Sphmrium lacustre (Miiller). Plentiful in one of the ponds. 

 Pisidium fontinale (Draparnaud). Not common. 



„ pusillum (Gmelin). Not common. 



,, nitidum (Jenyns). Not common. 



Ancylus fluviatilis (Miiller). Common. 

 Limncea peregra (Miiller). Abundant. 



CRUSTACEA. 



Amphipoda. 

 Gammarus pulex (Linne). Frequent in the stream. 



Copepoda. 



Cycloids pulchellusy Koch. A few in the net fixed in the stream, 

 „ serrulatus, Fischer. A few in material collected by hand- 

 net in one of the ponds. 

 „ crassicornis, Miiller. A few in the same material with 

 the last. 

 Cantkocamptus minutus (Miiller). Frequent in one of the ponds. 



OSTRACODA. 



Cypria exculpta (S. Fischer). Frequent in one of the ponds. 

 u* * ophthalmica (Jurine). Frequent in one of the ponds. 



