286 



ISOPODA. 



NORMAL1A. 



MONOPHTHALMA. 



Specific character. Oval, convex, eyes very large, uniting dorsally, ex- 

 tending obliquely backwards, the anterior margin of the first segment of the 

 pereion being deeply incised on each side for their reception, terminal segment 

 of the pleon flat, nearly semicircular, with a central carina terminating in a 

 point. 



Length, 2 inches. 



jEga monophthalma. JOHNSTON, in Loudon's Mag. Nat. Hist. vii. 



p. 233, f. 43. 



Rocinela monophthalma. MILNE EDWARDS, Crust, iii. p. 244. WHITE, 

 B. M. Cat. Brit. Crust, p. 80. Pop. Hist. 

 Brit. Crust, p. 252, pi. xiv. f. 7. GOSSE, Man. 

 Mar. Zool. 1, fig. 233. 



THE animal is oval, of a pale brown colour, approach- 

 ing to fleshy red, and when alive tinged with purple, 

 dotted all over with numerous punctures. The upper 

 antennae are very short, the two basal joints much 

 dilated, forming together a broad movable plate ; the 

 flagellum is setaceous, the lower antennas more than twice 

 the length of the superior, the three basal joints short 

 and unequal, the flagellum multiarticulate. The head is 

 almost entirely occupied by the large oblong eyes, which 



