Notes on the Crustacean Fauna of the English Lakes. 417 



sides, where there is a rank vegetation of Sphagnum and 

 water-grasses. Very probably, however, in the more sheltered 

 and weedy portions of the larger lakes they would be found ; 

 but be this as it may, the microscopist will be disposed to 

 think that their " room is better than their company," as they 

 have neither rarity nor beauty to recommend them. G. 0. 

 Sars and other naturalists have, in some of the large lakes of 

 Sweden, obtained some curious marine Amphipoda by dredg- 

 ing, thus affording an interesting confirmation of the fact, 

 that the Scandinavian peninsula is slowly rising from the sea ; 

 and though similar discoveries might not reward the naturalist 

 in our English lakes, it would still be worth while to try the 

 fortune of the dredge in some of them. 



The Crustacean inhabitants of our lakes belong, then, 

 almost exclusively, to the order Bntomostraca ; and of the 

 three divisions of that order which constitute the great bulk 

 of the British fresh-water species (Cladocera, Ostracoda, and 

 Copepoda) the Ostracoda are, on the whole, very poorly 

 represented. One very common species, Oypris ovum (Jurine), 

 exists in almost every collection of water, from the lowest to 

 the most elevated ; and in company with it, very often, a 

 closely allied species, G. laivis, Muller. Gypris compressa, 

 Baird, is of rather rarer occurrence ; while in Loughrigg Tarn, 

 and some of the small lakes of south Northumberland, I have 

 found a very fine species (G. obliqua, Brady), which is closely 

 related to, if not identical with, G. elliptica, Baird. Notoclro- 

 mas monachus (Muller) occurs abundantly in many of the lochs 

 of Selkirkshire and Dumfriesshire, as also a little member of 

 the family Cytheridee, Limnocythere inopinata, Baird, which is 

 probably much more common than it appears to be, but may 

 very readily be overlooked, owing to its minuteness, and to its 

 living almost entirely amongst mud. 



The group Copepoda includes several lacustrine genera — - 

 Diaptomus, Cyclops, and Canthocamptus — but the various 

 species have not as yet been adequately investigated. 



The third great division, Cladocera, is much more nume- 

 rously represented, and, so far as mountain districts are con- 

 cerned, forms much the most interesting section. It is not 

 needful or desirable to occupy the pages of this magazine with 

 technical descriptions of these species, especially as a mono- 

 graph of the more important families, comprising descriptions 

 of all the species, has recently been published, and is easily 

 accessible to all who are interested in the subject.* My 



* " A Monograph of the British Entomostraca, belonging to the families 

 Bosminidffi, Macrothricidae, aud Lynceidse." By the Rev. A. M\ Norman, M.A., 

 and G-eorge 3. Brady, M.B..C.3., C.M.Z.S. With six plates. London : Williams 

 and Norgate. 1867. 



VOL. XII. NO. VI. E E 



