98 BRITISH ENTOMOSTRACA. 



The antenna consists of a long, round body, formed of two 

 joints (t. XII, f. 1 a) -. the first, the smaller of the two ; the 

 second, much larger, cylindrical, and furnished with a 

 short seta on each side. This joint is terminated by a 

 long, sharp spine, which, at about the half of its length, 

 appears jointed. The first pair of feet (t. XII, f. 1 ^) 

 are exactly the same as in jmIcw. The shape of the shell 

 differs considerably from that of the female, being more 

 oval, less rounded on the dorsal edge, and having the 

 anterior margin straighter. 



The head, also, is rather longer, and even more erect 

 than in the female. 



Had. — Ponds and ditches in the neighbourhood of 

 London, Berwick, &c., and commonly met with during 

 all the summer and autumnal months. 



6. Daphnia rotunda. Tab. X, figs. 4, 4<5!; Tab. IX, 

 fig. 6, jun. 



Daphnia rotunda, S/rans, Mem.Mns. Hist. Nat., v, t. 29, f. 27, 28. 



— 31. Edwards, Hist. Nat. Crust., iii, 381. 



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

 Daphnia reticulata, Baird, Ann. Mag. Nat. Hist., i, 257, t. 9, f. 14. 

 Daphnia quadrangula (?), Koch, Dcutsch. Crust., h. xxxv, t. 19. 

 Daphnia mucronata (?), Koch, 1. c, h. xxxv, t. 20. 



{Younc/') Daphnia angulosa (?), Koch, 1. c, h. xxxv, t. 22. 



The shell or carapace in this species is nearly quite 

 round, and the inferior extremity is provided with a short, 

 blunt spine, projecting backwards. 



The head is small, depressed, and notched a little 

 above its junction with the body. 



The superior antennae are of moderate size, of a flattened 

 shape, square at the tip, and sending off" from its upper 

 edge a short, square branch (t. X, f. 4 a), both branches 

 being terminated by several short setse. The filaments 

 of the large antennae are not plumose. The surface of the 

 valves is denselv reticulated, being covered Avith a rei^ular 



