260 EEPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



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smaller, central, shield-like piece. The protergum, or what is usually 

 in the books called the prothorax, rei)resents either the scutum or both 

 scutum and scutellum, the two not being differentiated. 



The fore wings are long and narrow, and thicker than the hinder, 

 which are broad, thin, and membranous, and most active in flight, 

 and folded up like a fan when at rest and tucked away out of sight 

 under the fore wings, which act as wing covers. 



Turning now to the side of the body under the insertion of the wing 

 (Fig. 13), we see that the side of each of the middle and hind thoracic 

 rings is composed of two pieces, the anterior, ejyisternum^ resting on the 

 sternum, with the epimerwn behind it j these pieces are vertically high 

 and narrow, and to them the leg is inserted by three pieces, called re- 

 spectively coxa, trocliantine, and trochanter (see Fig. 13), the latter form- 

 ing a true joint of the leg. 



The legs consist of five well-marked joints, the femur (thigh), tibia 

 (shank), and farsz^s (foot), consisting in the locustof three joints, the third 

 bearing two large claws with a pad between them. The hind legs, es- 

 pecially 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 pro- 

 jection between the legs. 



The head is mainly, in the adult locust, ccTm posed of a single piece called 

 the eiricranium (Figs. 13 and 13 J, E), and which carries the eyes, ocelli, or 

 simple eyes (Fig. 13J, e), and antennae. While there 

 are in reality four primary segments in the head of all 

 winged insects, corresponding to the four pairs of ap- 

 pendages in the head, the i)osterior three segments 

 after early embryonic life in the locust become obso- 

 lete, and are mainly represented by their appendages 

 and small portions to which the appendages are at- 

 tached. The epicranium represents the antennal seg- 

 ment, and most of the piece represents the tergum of 

 Tifwof thnTeS'o^f'a tlie segment. The antennae, or feelers, are inserted in 

 iC^VSypeusr^; froiit of the eyes, and between them is the anterior 

 Iv^e™' antei?na-^'4J' occllus, or simplc cyc, whilc the two posterior ocelli are 

 DiaQdibie; mx, portion gituatcd abovc the insertion of the antennae. In front 



CI maxilla uncoTerecl 



nLr'"'' ai'"'^™' mSjm ^^ ^^^ epicranium is the clypeus (Fig. 13), a piece nearly 

 palpus. (Kingsiej del.) twicc as broad as long. To the clypeus is attached a 

 loose flap, which covers the jaws when they are at rest. This is the up- 

 per lip or lahrum (Fig. 13). There are three pairs of mouth-appendages: 

 first, the true jaws or mandibles (Fig. 12), which are single-jointed, 

 and are broad, short, solid, with a toothed cutting and grinding edge, 

 adapted for biting. The mandibles are situated on each side of the 

 mouth-opening. Behind the mandibles are the maxillae (Fig. 12), which 

 are divided into three lobes, the inner armed with teeth or spines, the 



