EGIDA. 275 
Samouelle into his work on British Insects, without, how- 
ever, any locality being subjoined, and, as it is omitted by 
Mr. White in his Catalogues of the British Crustacea, 
it seems evident that no tradition exists in the British 
Museum (of which Mr. Samouelle was also an officer) 
to warrant its introduction. As it is possible, however, 
that it or some other of these fish-parasites may occur, 
we have introduced the above family characters. 
In the second tribe of Milne Edwards, forming our 
Fam.—ZGID/A, 
The species are amongst the largest known Isopods, 
and are distinguished by having their antenne fixed 
in front of the head, the basal joint of the anterior pair 
being very broad and flat, and uniting together to form 
a margin in front of the head, not being concealed 
beneath the advanced cephalon; the outer-foot jaws 
have the basal joints moderately dilated, with three 
or four terminal joints, which are rarely palpiform; the 
pereiopoda are of moderate length, the anterior pair 
being generally the strongest and fitted for prehension, 
being terminated by a robust curved finger, acute at the 
tip; whilst the hind legs are gradually’ elongated and 
fitted for walking. The five segments of the pleon are 
very short, each on its underside supporting a pair of 
double foliaceous plates for respiration, whilst the last 
segment of the pleon is large and flat, and bears on each 
side near the base a pair of flat appendages, scales arising 
from a basal joint, of which the inner angle is sometimes 
produced into a long style. 
