276 GID A. 
TSOPODA. GID, 
NORMALTA. 
Genus—/AGA. (Leach). 
Generic character. The three anterior pairs of legs in this 
genus are strong and terminated by a powerful hook-like finger, 
whilst the four posterior pairs are longer and more slender, 
with a but slightly curved terminal finger, so as to fit them 
for progression; the short inner antenne have the basal joints 
very broad and flattened, occupying the front margin of the 
head. 
Tne species of this genus are of large size. They 
are oval, moderately convex, with most of the segments 
marked transversely with a slight ridge. The coxe or 
first joint of the legs (epimeral pieces of Milne Edwards) 
are formed so as to appear as part of the dorsal surface. 
The eyes are of large size and oval, extending consider- 
ably backwards at the sides. 
The outer antenne are affixed beneath the fore margin 
of the head, and are separated from each other by an ele- 
vated scutcheon-like piece or labrum ; they are composed 
of five or six strong basal joints gradually increasing in 
length, but diminishing in thickness, and are terminated 
by a flagellum composed of about a dozen articulations. 
The mandibles are strong, with the apical portion angu- 
lated and bifid ; they are furnished with a prominent three- 
jointed palpiform appendage arising near the external 
base. The outer-foot jaws are rather valve-shaped, with 
the basal joint strong and elongated, bearing a triangular 
