THE FRESH-WATER ENTOMOSTRACA OF ABERDEENSHIRE 217 



ing from one loch recently visited (Loch of Park), as many 

 as forty-four species were obtained, while thirty-nine, thirty, 

 and twenty-seven species respectively have been obtained in 

 gatherings from other lochs. 



I propose, in the following notes, to mention a few of 

 the rarer or more interesting species that have been ob- 

 served ; and those that belong to the Cladocera will be 

 referred to first, and afterwards those belonging to the 

 Ostracoda and the Copepoda. 



THE CLADOCERA. 



The Cladocera obtained in gatherings recently collected, though 

 perhaps not more numerous individually than the Ostracoda or 

 the Copepoda, are represented by a greater number of species. All 

 the families of the Cladocera, except the Holopedida and Lepto- 

 doridce, are represented, and both Holopedinm and Leptodora may 

 yet be found in some of the hill lochs, but as these are pelagic 

 forms, a boat and tow-net may be required to capture them ; the 

 gatherings referred to in these notes are all shore gatherings. 



The SIDAD.E are represented in recent gatherings by Si da 

 crystallina (O. F. Miiller) and Daphnella brachyura (Lievin), (or 

 Diaphanosoma brachynruin as it is now called) ; the first is common 

 in the Loch of Skene, and the other is equally common in Loch of 

 Park. Latona setifera, another member of the same family, and 

 much rarer than either of the two species just referred to, was also 

 obtained in Loch of Park, as well as in a gathering from Corby 

 Loch, but only one or two specimens of Latona were obtained in 

 each of these gatherings. 



The DAPHNID^: observed in recent gatherings include several 

 interesting species, but I can only at present record three of them, 

 viz. Ceriodaphnia laticaudata, P. E. Miiller, Ceriodaphnia megalops, 

 G. O. Sars, and Scapholeberis mucronata (O. F. Miiller). The first, 

 which has a comparatively broad and angulated post-abdomen, was 

 obtained in Corby Loch. The second, which is the largest of the 

 British species of Ceriodaphnia, and which occurred in a gathering 

 from Loch of Park, has not previously been observed in Scotland ; 

 in this species the shell is distinctly but somewhat irregularly striate, 

 after the manner of a Simocephalus only females have been observed 

 so far. The third (Scapholeberis) has been obtained in Loch of 

 Skene, Loch of Park, and Corby Loch, and also in one of the 

 ponds in Duthie Park. Amongst the specimens collected, some 

 have the head rounded and without a tooth, others possess a vertex 

 tooth which varies in length in different individuals, and the length 

 of the posterior spines also varies more or less. 



