230 
HISTORY OF BRITISH CRUSTACEA. 
various parts of the Irish and Scottish coasts, sometimes 
associated with an almost equally destructive Crustacean 
already described, the Chelura . 
Gen. 113. ASELLUS, Geoffr. 
Caudal appendages long. Eront legs the largest ; claws 
simple. Eyes small, lateral. Lower antenna of the same 
length as the bristle-bearing joint of the outer pair. Body 
oblong, depressed, and deeply divided into nine joints ; one 
being the head, seven the thorax, and one the abdomen. 
Asellus aquaticus, L. Water Hog-louse. (Plate XII. 
tig. 6.) — Head large; inner antennae shorter than peduncle 
of second pair; peduncle of posterior appendages of abdo- 
men cylindrical, with tw 7 o stylets of same length. Six or 
seven lines long. 
Common in fresh and stagnant water : the male much 
larger than the female. Its usual walk is slow, but when 
pursued it can run quickly. 
Caudal appendages very minute. Eront legs not thicker 
Gen. 114. J/EBA, Leach. 
