THE FRESH-WATER ENTOMOSTRACA OF ABERDEENSIIIRE 219 



Park ; P. uncinatus was also observed in Corby Loch. Chydorus 

 barbatits (Brady) occurred in Loch of Skene, Bishop Loch, and 

 Loch of Park. 



The POLYPHEMID^E are represented by only one species Poly- 

 phemus pedicuhis (Lin.), which occurred in all the lochs examined 

 except Corby Loch. Bythotrephis lotigimanus, Leydig, another of 

 the Polyphemidse so common in some of the Lochs of Scotland, has 

 not been observed in any of the Aberdeenshire lochs hitherto 

 examined. 



THE OSTRACODA. 



Only eight species of Ostracoda have been observed in the 

 gatherings of fresh -water Entomostraca recently collected, all of 

 which are moderately common. Cypris exculpta, Fischer, occurred 

 in Loch of Skene, Loch of Park, and Corby Loch ; Herpetocypris 

 reptans (Baird) and Cypridopsis villosa (Jurine) were frequent in Loch 

 of Park, while Limnicythere inopinata (Baird) was obtained in Corby 

 Loch. In September 1890 I examined the north end of Loch 

 Strathbeg, 1 and obtained ten species of Ostracoda there ; but, with 

 the exception of Cypridopsis aculeata (Lillj.) and Ilyocypris biplicata 

 (Koch), they are all similar to those recently observed. Only one 

 species of Candona (Candona Candida) has been observed in the lochs 

 of Aberdeenshire hitherto examined. 



THE COPEPODA. 



The Copepoda obtained in the Aberdeenshire lochs recently 

 examined comprise even a greater number of rare forms than those 

 that have been found amongst the Cladocera, but these rare forms 

 belong partly to the Cydopida and partly to the Harpactiddce ; the 

 only Diaptomus observed hitherto is the common Diaptomus gradlis, 

 G. O. Sars, which was moderately abundant in Loch of Skene, and 

 was also obtained in Corby Loch and Bishop Loch. Amongst the 

 Cyclop idee, Cyclops dyboivskii, Lande, was moderately frequent in a 

 gathering from Loch of Park ; this species requires careful examina- 

 tion to distinguish it from Cyclops oitlionoides, G. O. Sars. Loch 

 Lomond is the only other loch in Scotland where I have obtained 

 this species ; it occurred there in a shore gathering collected to the 

 south of Balmaha. Cyclops langiddus, G. O. Sars, another rare 

 species, was obtained in a gathering from Corby Loch ; this Cyclops, 

 which has the antennules sixteen-jointed, has only hitherto been 

 observed in Scotland in Loch Boon in Ayrshire. Cyclops fuscus 

 (Jurine) was obtained in a gathering from Loch of Park, so also 

 were Cyclops macrurus, G. O. Sars, and Cyclops affinis, G. O. Sars ; 



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

 p. 282 (1891). 



