124 BRITISH ENTOMOSTRACA. 



1. EURYCERCUS LAMELLATUS. Tab. XV, figS. 1, 1 a-l. 



LYNCEUS LAMELLATUS, Mutter, Zool. Dan. Prod., No. 3396, 1776 ; 



Entoinost., 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, Deutsck. Crust., h. xxxvi, t. 9. 

 MONOCULUS LAMELLATUS, Gmelin, Linn. Syst. Nat., 3008, No. 62. 



Ma/niel, Eucyc. 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 Dnphnia 

 pulcx, and jointed about the middle of their length. 



Eye large, contained in its funnel-shaped sheath of 

 muscles, areolar ; arcola? 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. 



