ON THE BEITIsn SPECIES OF ENTOMOSTEACA , ETC. 217 



XII. — On the British Species of Entomostraca belonging to 

 Daphnia and other allied genera. By Geoege Stewaedson 

 Beadt, M.D., LL.D., T.R.S. (Plates VII.-X.) 



Since the publication of Dr. Baird's classical work on the British 

 Entomostraca in 1850 nothing has appeared in print respecting 

 the British species of Baphnice except casual and fragmentary- 

 notices, and even of these not very many. Dr. Baird himself 

 published in the "Edinburgh New Philosophical Journal" an 

 article on the Food of freshwater Fishes, in which a new species 

 of Daphnia was described. Mr, D. J. Scourfield has contributed 

 some interesting papers to the " Journal of the Quekett Micro- 

 scopical Club" and the "Journal of the Linnean Society," which 

 deal partly with Daphnice ; Mr. Thomas Scott has noticed cer- 

 tain species in the Annual Reports of the Fishery Board for 

 Scotland ; Dr. Creighton has published a list of Irish species in 

 the "Irish ITaturalist," and Mr. T. Y. Hodgson a list of the 

 British Cladocera in the "Journal of the Birmingham Natural 

 History and Philosophical Society." Dealing with matters of 

 embryology and physiology rather than morphology, Messrs. 

 Hardy and McDougall have published in the "Proceedings of 

 the Cambridge Philosophical Society" a paper on the "Structure 

 and functions of the alimentary canal of Daphnia,'''' and Sir 

 John Lubbock in the "Philosophical Transactions" one on "Two 

 methods of reproduction in Daphnia and on the structure of the 

 Ephippium." This very small list embraces, so far as I know, 

 all the existing literature of the British Daphnice, excepting only 

 short papers in popular serials. Much, however, has been pub- 

 lished on the Continent. Among the more important memoirs 

 are those of Professor Gr. 0. Sars, which, as to European species, 

 are unfortunately devoid of illustrations. Equally valuable are 

 the various monographs of Schoedler, Daday de Dees, Hellich, 

 Richard, Eylmann, Stingelin, and others, while the older and 

 more elaborate monograph of Ley dig — " Naturgeschichte der 

 Daphniden " — is in itself a storehouse of information on the mor- 

 phology aod physiology of the group. From across the Atlantic 



