A HISTORY OF WARWICKSHIRE 



cephalic crest. * The head, in fact, presents the form of a hood more or 

 less curved in a dorsal direction, laterally flattened. Thus the ventral 

 margin forms a regularly convex line, while the dorsal margin is con- 

 cave. The head attains half the length of the body (not including the 

 caudal spine, which is almost as long as the head).' He does not accept 

 any English locality for it, but believes the form commonly noted under 

 the name cederstromii to be a variety of H, jardinii, for which he proposes 

 the name incerta on account of the uncertainties arising from its confusion 

 with the true cederstromii^ 



The upshot of all these explanations is to credit Warwickshire with 

 Daphnia pulex, var. brevispina, Daday de Dees ; Z). longispina, O. F. 

 M tiller ; D. galeata, Sars ; Hyalodapbnia jardinii, var. incerta, Richard ; 

 and H. kablbergiensis, Schodler. According to Lilljeborg, in his 

 important work just issued, the last of these should be called Daphnia 

 (Hyalodaphnia] cucullata, Sars. 1 It is indeed only in Utopia that the 

 student can expect to rest and be thankful over a final settlement of 

 zoological names. 



Belonging to the same family of the Daphniida? Mr. Hodgson 

 records Simocepbalus ve'tu/us (O. F. Miiller), * abundant in clear weedy 

 water, canals'; Scapholeberis mucronata (O. F. M.), ' common : Olton, 

 Kingswood, Middleton, Hagley Park ' ; Ceriodaphnia reticulata (Jurine), 

 'Middleton, Olton'; C. rotunda (Straus), 'generally distributed'; 

 C. quadrangula (O. F. M.), ' Barnt Green, Middleton'; C. megalop s, 

 Sars, ' Lower Bittel Reservoir, Olton Mill' ; and Moina rectirostris 

 (O. F. M.), ' a horsepond near Harborne.' All these genera were at one 

 time included under Daphnia, and the first three of them still were so in 

 1850 when the Ray Society published Dr. Baird's valuable book on 

 The Natural History of the British Entomostraca. In that volume Baird 

 distinguished Moina, which has the first antennae of the female long and 

 inserted on each side of the head's ventral margin, from the other 

 Daphniidae, in which these antennae are small and inserted under the 

 rostrum or on the head's hind margin. Simocepbalus, Schodler, has its 

 shell covering marked with sub-parallel transverse lines, whereas in 

 Daphnia and others there is a reticulation of little quadrate or polygonal 

 meshes. In Ceriodaphnia, Dana, the first antenna? of the female are 

 movable, while in Daphnia and Hyalodaphnia they are immovable, and 

 from these three Scapholeberis, Schodler, is differentiated by having the 

 ventral margin almost straight in continuity with the caudal spine, and 

 by having a distinct hind margin. In the others the convex ventral and 

 dorsal margins meet at the caudal spine, so that the hind margin remains 

 undefined as in the bow of a boat. 



In the family Bosminida? the records are Eosmina longirostris (O. F. 

 Mtiller) and B. longispina, Leydig, of which the former is said to have 

 the 'head erect, not tumid above,' the latter to have the 'head depressed, 

 tumid above.' It may be worth while here to notice that in describing 



1 Ann. Set. Nat. ser. 8, ii. 331, 343 (1896). 

 8 ClaJocera Sueci*, p. 127. 



1 80 



