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 pieces, 

 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), tibia (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, E\ which 

 carries the compound eyes, ocelli, or simple eyes (Fig. 275, 

 e), and antennae. 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 

 mostly corresponds to the tergum of the seg- 

 ment - The antennae, or feelers, are in- 



SGrted in frOIlt f the G J eS > and between 



^ em * 8 the anterior ocellus, or simple eye, 

 by the labrum ; p, while the two posterior ocelli are situated 



maxillary palpus; p ', , . . . . , T 



labial paipus.-Kings- above the insertion of the antennae. In 

 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). 



