286 ZOOLOGY, 
and Europe, which we have called Syncarida, and 
which have antenne and tails like shrimps, but the body 
one” 249.—Gampsonyx fimbriatus of European coal measures, 2% times natural 
and limbs like Amphipods. In the Isopods the body is flat- 
tened and the head rather broad. 
Fig. 251 is a dorsal view of Serolis Gau- 
dichaudi Audouin and Edwards, with the 
two pairs of antenne and pointed sides of 
each thoracic segment, dissected to show the 
nervous system, the two pairs of antennal 
nerves ; the optic nerves (op) sent to the 
compound eyes. Fig. 252 represents a trans- 
verse section of the body, showing the mode 
of insertion of the legs, and the equality in 
the tergal and sternal sides of the body, 
Fig. 254 represents a gill, In the common 
pill-bug (Porcellio) aérial respiration is per- 
formed by respiratory cavities situated in 
the abdomen. In Tylos similar cavities are 
filled with a multitude of branching cceca, 
serving for aérial respiration, thus antici- 
pating the tracheary system of insects. 
The nervous system is quite simple. (Fig. 
250, Idotea, and Fig. 251, that of Serolis.) 
The digestive canai is straight, consisting 
Fig. 250.—Nervons of a short cesophagus, a membranous stom- 
system OF ae ys. ach, and usually a short tubular intestine ; 
#: Kingsley: the liver consisting of several short coca. 
In Serolis Gaudichaudt the stomach is somewhat pear- 
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