124 
BRITISH ENTOMOSTRACA. 
1 . Eurycercus lamellatus. Tab. XV, figs. 1, 1 a-l. 
Lynceus lamellatus, Muller, Zool. Dan. Prod., No. 3396, 1776 ; 
Entomost., 73, t. 9, f. 4-6. 
— Latreille, Hist. Nat. Crust., 208. 
— Baird, Trans. Berw. Nat. Club, i, 100. 
— M. Edwards, Hist. Nat. Crust., iii, 388. 
— Koch, Deutsch. Crust., h. xxxvi, t. 9. 
Monoculus lamellatus, Gtmelin, Linn. Syst. Nat., 3008, No. 62. 
— Manuel, Encye. meth., vii, 733, No. 62, 
t. 268, f. 21-3. 
— Fabricius, Ent. Syst., ii, 498. 
Eurycercus lamellatus, Baird, Ann. Mag. Nat. Hist.,ii, 88, t.2, f.1-8. 
1843 ; Trans. Berw. Nat. Club, ii, 150. 
This is the largest of all the known species of this 
family, being in old specimens fully as large as the 
Daphnia vetula . 
Shell of an olive colour ; rather square-shaped, ciliated 
on anterior margin ; ventricose in centre, and arched on 
posterior edge. Beak rather blunt and short. 
Superior antennae are stout, solid bodies, somewhat 
conical in shape, slightly curved, and terminating in 
six short spines, each of which gives out a fine seta or 
bristle. They are not possessed of much motion. In- 
ferior antennae or rami very short, compared with the 
size of the insect, and two-branched ; both branches of 
about equal length. The anterior branch has five long 
filaments, one from the extremity of first and second 
joints, and three from the third ; this joint has also a 
short spine. The posterior branch has three long fila- 
ments, all springing from the extremity of last joint, and 
the first and second have each only a short spine. These 
filaments are finely plumose, like those of the Daplinia 
pulex , and jointed about the middle of their length. 
Eye large, contained in its funnel-shaped sheath of 
muscles, areolar ; areolae about twenty in number. The 
accompanying black spot is remarkably small, situated 
almost directly under the eye instead of in front, and is 
somewhat of a square shape. 
