436 D. J. SCOURFIELD, SYNOPSIS OF THE KNOWN SPECIES OF 



S. serrulatus (Koch). 



I have only had this species from the following localities ; 

 Richmond Park, Kew Gardens, Ditch between Kew and Rich- 

 mond, and Newborough, Anglesey. My friend Mr. C. J. H. 

 Sidwell has also found it at Hanwell. It does not seem to have 

 been recorded by any other writer in this country. 



Ceriodaphnia Dana. 

 C reticulata Jurine. 



Daphnia reticulata Baird (1), ? Brady (4). 

 There exist at least three varieties of this species in this 

 country : namely, the typical form ; a form with enormously 

 extended fornices — the var. serrata of Sars and Lilljeborg ; and a 

 very small form, probably C. kurzii Stingelin. 



C megalops Sars. 



Daphnia reticulata Baird (in part) (1) Tab. YII. fig. 5. 

 Moderately common in the south and east of England, but 

 apparently rare in the north. Only one record from Scotland, 

 namely. Loch of Park, Aberdeen (Scott 22), and one or two from 

 Ireland. Not seen in North Wales. 



C. quadrangula (O. F. Muller). 



C. pulchella Scourfield (28) Creighton (6). 

 This is a common species in the lakes of the north of England, 

 North Wales, Scotland, and Ireland, but has only been seen once 

 or twice in the south and east of England, its place being taken 

 apparently by the next species. 



C. pulchella Sars. 



C. quadrangula Scourfield (25, 26, 29), Hodgson (10). 

 The distribution of this species seems to be exactly opposite to 

 the foregoing, as it is common in the south and east of England, 

 rare in the north, and has not been certainly identified in either 

 Wales or Scotland. 



C. affinis Lilljeborg. 



C. scitula Scourfield (29), Sprague (33). 

 There is some doubt whether this species is really C. scitula 



