ON SOME FRESH AND BRACKISH WATER ENTOMOSTRACA 159 



the other hand, was observed in two of the gatherings from 

 Loch Callater, obtained by tow-netting. Both these species 

 of Cladocera have been found moderately common in some 

 of the lochs of the south and west of Scotland. Sida 

 crystallina (Miiller) occurred in Loch Vrotachan and Loch 

 Phadruig ; Ceriodaphium quadrangula (Miiller) was also 

 obtained in Loch Phadruig. Acantholeberis curvirostris 

 (Miiller) was moderately frequent it occurred in four 

 gatherings from Loch Phadruig, in one from a loch or tarn 

 above Loch Vrotachan, and in another from a large pool 

 near Loch Avon. The pretty Graptolebcris testudinaria 

 (Fischer) was obtained from Loch Vrotachan, and Alona 

 rustica from Loch Phadruig. A single specimen of the 

 somewhat rare Chydorus globosiis, Baird, was obtained from 

 Loch Callater and also from Loch Davan. CJiydoriis bar- 

 batus (Brady) was another of the Loch Callater species, and 

 it also occurred in Loch Phadruig. In my previous paper 

 I referred to the absence of Leptodora hyalina, Lilljeborg, in 

 the lochs which had at that time been examined ; and it 

 also appears to be an absentee from the lochs examined by 

 Mr. Clark. Its absence from these lochs can scarcely be 

 attributed either to their limited size or to their situation ; 

 for its distribution in Scotland shows that although it occurs 

 in several of the larger lochs it is not confined to them, 

 but is moderately frequent in others which differ little in 

 size or depth from those in Aberdeenshire. Perhaps if 

 these lochs could be more extensively tow -netted during 

 the summer months interesting results might be obtained. 

 I have shown by numerous statistics * that Leptodora, while 

 frequent or common in lochs during summer and autumn, 

 was often altogether absent during the colder months. In 

 order to show the extensive distribution of Leptodora, I 

 give here the names of a number of lochs, beginning with 

 those in the south of Scotland, in which this fine species 

 has been found: Loch Maben (where, in 1882 or 1883, 

 Leptodora was discovered for the first time in Scotland, 

 by the Rev. A. M. Norman) ; Loch Boon (Ayrshire) ; Loch 

 Lomond ; Loch Arklet ; Loch Katrine and Loch Achray 



1 Seventeenth "Annual Report of the Fishery Board for Scotland," part iii. 

 p. 132 et seq. 



