ARTICULATA. a3 
pendages, feelers, jaws, claws, and legs beneath the ceph- 
alo-thorax, and flat swimmerets under the abdomen. In 
fact, as a rule, every segment, carries a pair of movable 
appendages. The seven segments of the head are com- 
pressed into a very small space, yet have the following 
members: the eye-stalks; the short and long antenne; 
the mandibles, or jaws, 
between which the 
mouth opens; the two 
pairs of maxillz; and 
a pair of modified 
limbs, called “ foot- 
jaws.” The thorax 
carries two more pairs 
of foot-jaws, and five 
pairs of legs. The 
foremost legs, “the 
great claws,’ are ex- 
traordinarily — devel- 
oped, and terminated 
by strong pincers 
(chele). Of the four 
slender pairs succeed- 
ing, two are furnished 
with claws, and two 
are pointed. The last “\Yster Lobster (datacus feviatiia)s a Bret ait 
pair of swimmerets, to- of antenne; b, second pair; ec, eyes; d, audi- 
4 tory tubercles; e, foot-jaws; f, g, first and fifth 
evether with the ‘telson, pair of thoracic legs; h, false abdominal feet ; 7, 
form the caudal fn— 9 “"™"* "omen 
the main instrument of locomotion; the others (called 
“false feet”) are used by the female for carrying her eggs. 
The eyes are raised on stalks so as to be movable (since 
the head is fixed to the thorax), and are compound, made 
up of about 2500 square facets. At the base of each 
small antenna is a minute sac, whose mouth is guarded by 
18 
