312 ZOOLOGY. 
Turning now to the side of the body under the insertion 
_of the wing (Fig. 274), we see that the side of each of the 
middle and hind thoracic rings is composed of two rieces, 
the anterior, episternum, resting on the sternum, with the 
epimerum behind it; these pieces are vertically high and 
narrow, and to them the leg is inserted by three pieces, 
called respectively coxa, trochantine, and trochanter (see Fig. 
274), the latter forming a true joint of the leg. 
The legs consist of five well-marked joints, the femur 
(thigh), ¢¢dia (shank), and tarsus (foot), the latter consist- 
ing in the locust of three joints, the third bearing two large 
claws with a pad between them. The hind legs, especially 
the femur and tibia, are very large, adapted for hopping. 
The sternum is broad and large in the middle and hind 
thorax, but small and obscurely limited in the prothorax, 
with a large conical projection between the legs. 
The head is mainly in the adult locust composed of a sin- 
gle piece called the epicranium (Figs. 274 and 275, #), which 
carries the compound eyes, ocelli, or simple eyes (Fig. 275, 
e), and antenne. While there are in real- 
ity four primary segments in the head of 
all winged insects, corresponding to the 
four pairs of appendages in the head, the 
posterior three segments, after early em- 
bryonic life in the locust, become obsolete, 
and are mainly represented by their ap- 
pendages and by small portions to which the 
appendages are attached. The epicranium 
represents the antennal segment, and 
vin ofieshad or’ mostly corresponds to the tergum of the seg- 
spretus, FE, epicrani- ment. The antenns, or feelers, are in- 
um; C, clypeus; Z, : 
labrum; 00, ocells ¢ gerted in front of the eyes, and between 
eye; @, antenna, md, ‘ - : 
mandible; mz,portion them is the anterior ocellus, or simple eye, 
of maxilla uncovered ‘ a S :, 
by the labram; 2, while the two posterior ocelli are situated 
illary palpus; p’, . : 
inutal gal pus Kings: above the insertion of the antenne. In 
aici front of the epicranium is the clypeus (Fig. 
275), a piece nearly twice as broad as long. To the clypeus 
is attached a loose flap, which covers the jaws when they 
are at rest. This is the upper lip or labrum (Fig. 275). 
