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CRUSTACEANS, 
and the antennas are not furnished with an external scale-like basal piece. The 
best known members of this group are the Palinuridoe, or rock-lobsters, one member 
of which, the crawfish (Palinurus vulgaris), may be seen for sale in England. 
It is larger than the lobster, 
and has enormously long stout 
antennae, and a spiny carapace 
but no claws. This species is 
figured on the left side of 
the coloured Plate. The second 
family, Scyllaridce, contains a 
considerable number of genera 
( Scyllarus,Ibacus , etc.), mostly 
from tropical seas, remarkable 
for having the carapace broad 
and flattened, with the eyes 
enclosed in complete orbits on 
its upper surface, and the 
antennae short and scale-like. 
In this tribe the larvae are 
LARVA OF CRAYFISH, THE SO-CALLED ~GLASS-CRAB (nat. size). Ulllike those Of Cl’abs Or 
lobsters. On account of their 
transparency and delicacy they are called glass-crabs. The body is formed of three 
distinct parts, a large round-sided head, a smaller but also round-sided thorax, and 
a minute jointed abdomen which projects like a short tail from the hinder end of 
the thorax. The abdomen bears no limbs. 
The lobsters and crayfish (Astacidea), have at least three pairs of the 
large thoracic limbs pincer-like, the first being much larger than the others. The 
slender-clawed crayfish, Willemcesia leptodactyla (nat. size). 
