DAPHNIA. 99 



network, of small, irregular pentagonal cells. The colour 

 is generally somewhat red. The sixth segment of the 

 body is destitute of the spur which is found in the reticu- 

 lata. The ova are more numerous. The whole animal 

 is larger, and it possesses a greater density of structure. 



Hob. Ponds and ditches in the neighbourhood of 

 London, during summer and autumn. 



7. DAPHNIA MUCRONATA. Tab. X, figs. 2, 3. 



DAPHNE MUCRONATA, Miiller, Zool. Dan. Prod., No. 2404, 1776. 

 DAPHNIA MUCRONATA, Miiller, Eutomost, 94, t. 13, f. 5, 6. 



Desmarest, Cons. gen. Crust., 374. 

 Latreille, Hist. Nat. Crust., iv, 229. 

 Bosc, Man. d'Hist. Nat. Crust, ii, 281. 

 M. Edwards, Hist. Nat. Crust., iii, 382. 

 Baird, Trans. Berw. Nat. Club, ii, 148. 

 MONOCULUS MUCRONATUS, Gmelin, Linn. Syst. Nat., edit. 13th, i, 3000, 



No. 28. 



Manuel, Enc. meth., t. 265, f. 19. 

 Jurine, Hist. Nat. Mouoc.,137,t.l4,f.l, 2. 

 MONOCULUS BISPINOSUS, De Geer, Mem. servir Hist. Ins., vii, 463, 



t. 28, f. 3-8, 1778. 

 Falricius, Ent. Syst., ii, 493. 

 DAPHNIA BISPINOSA, Koch, Deutsch. Crust., h. viii, t. 1. 



This species is readily distinguished by the anterior 

 edge of the shell being quite straight, and terminating 

 inferiorly by a spinous point of considerable length. 



The head is of a triangular shape, and the eye is large. 



Superior antennae short. 



Filaments of inferior antennae not plumose. 



The back is impressed with a deep indentation at the 

 root of the head ; and the anterior margin is marked with 

 brownish coloured bands, and densely ciliated. 



The colour of the whole animal is of a dark gray. 



The form of the head varies in this species, being 

 sometimes rounded, and at others terminated by a sharp, 

 somewhat curved point directed upwards. 



