1902-190 3.] Dzstribution of the Smaller Crustacea. 3 
these circumstances I had expected that the entomostraca 
would have become more crowded together, and that a larger 
gathering would thus be obtained. The actual result, how- 
ever, was very different. Entomostraca of any kind were 
few, and as for Daphnia, not a single specimen was got, 
even though the pond was carefully searched. Probably in 
this case the warm dry weather, acting on a decreasing body 
of water, had killed them. In this connection I would refer 
to the joint observations of Mr Lindsay and myself at the 
Upper Elf Loch, Braids, in the years 1896, ’97, and ’98, the 
results of which were communicated to the Society in two 
papers now embodied in the Society’s ‘Transactions.’ In the 
second of these papers will be found a description and tabular 
view of the seasonal variations in the entomostraca of this 
little sheet of water—some of these variations being rather 
remarkable.’ 
Amongst the many species met with in the lochs of Scot- 
land, the following may be mentioned as being more markedly 
susceptible to ordinary seasonal influences. Holopedium gib- 
berum was common in Loch Arklet in September and Novem- 
ber 1897, and abundant in June 1898, but not a trace of it 
was observed on the 15th of March of the latter year. It 
was common in Loch Achray in September 1897 and June 
1898, but was entirely absent on November 27 and March 
17. It was common in Loch Doon (Ayrshire) on J uly 6, 
-1898, but was not observed in September, December, and 
March preceding. The same species was taken in Loch Oich 
in August 1897 and in August and October 1898, but was 
absent from the gatherings collected in December and January. 
Two other species of cladocera also exhibit a somewhat marked 
susceptibility to seasonal changes, but the first more distinctly 
so than the other. In the lochs in which they occur they 
are usually common in the summer months, but are scarce or 
absent in winter. 
_ Amongst the pelagic copepoda which I have found in the 
lochs of Scotland, the only species which exhibited any marked 
susceptibility to seasonal influence is Diaptomus laciniatus, 
Lilljeborg. This species was found in Loch Doon, in Ayr- 
' See ‘Transactions,’ vol. iii, pp. 375-378. 
