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HISTORY OF BRITISH CRUSTACEA. 
corded as British; the latter was found on a dolphin, and is 
described by Mr. Gosse. 
Order III. ISOPODA. 
Most of the Crustacea of this distinct Order would have 
been included in the genus Oniscus of Linnaeus. The ab- 
domen is much developed ; the body is depressed, in gene- 
ral rather wide and divided into segments. There are gene- 
rally fourteen legs, which terminate in a pointed claw. The 
most of these legs in the female have a large horny plate, 
extending horizontally inwards, and forming with the others 
a large pouch beneath the thorax, which contains the eggs. 
Mouth-apparatus well developed. Many of the rings of the 
abdomen are often confounded together, so as to appear a 
single joint. The tail is formed of a variable number of 
segments bearing the branchiae, and often furnished with 
plates which cover them. Many of the species form the 
favourite food of fish, and the remains of them are often met 
with in their stomachs. 
The first Suborder contains the Walking Isopods, in 
which the last false legs are styliform or opercular, but never 
form a lamellar caudal fin. 
