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Part III. — Eiffhth 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 Entoinos- 
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 1 3th, 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 Gammaras, 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 Limnwa perer/ra 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 4 Botanical pond ' Conferva was moderately common. 
The following are the species of Mollusca and Crustacea observed in 
this section : — 
MOLLUSCA. 
Sphoji'ium lacustve (Miiller). Plentiful in one of the ponds. 
Pisidium fontinale (Draparnaud). Not common. 
„ pusillum (Gmelin). Not common. 
nitidum (Jenyns). Not common. 
Ancylus fluviatilis (Miiller). Common. 
Limima peregra (Miiller). Abundant. 
CRUSTACEA. 
Amphipoda. 
Gammarus pulex (Linne). Frequent in the stream. 
Copepoda. 
Cyclops pulchelhts, 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. 
Canthocamptus 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. 
