HARD PARTS OF THE GRASSHOPPER. 



241 



c. The femur ) a long, swollen, club-shaped segment 

 (Figs. 130, 10, and 132, /, /,/"), which makes up 

 nearly half the length of the limb. When the animal is 

 at rest the femur of the third or leaping leg extends up- 

 wards and back wards, with its distal end above the dorsal 

 surface of the body, as in Fig. 139, Fern. 



This joint contains the powerful leaping muscles, the 

 areas indicating the points of attachment of which are 

 visible externally. 



FIG. 130. 



FIG. 130. Side view of head and prothorax of grasshopper ( Acridium 

 Americanum). (Drawn from nature by W. K. Brooks.) 



a. Antenna, b. Ocellus, c. Eye. d, d. Epicranium. e. Clypeus. 

 y. Labrum. i. Gena. k. Maxilla. I. Labium. m. Maxillary palpus. 

 n. Labial palpus. o. Mandible. 1. Lateral portion of pronotum. 

 2. Dorsal portion of pronotum. 3. Prothoracic prescutum. 4- Protho- 

 racic scutum. 5. Prothoracic scutellum. 6. Prothoracic postscuiellum. 

 7. Prosternum. 8. Coxa of first leg. 10. Femur of first leg. 



In the grasshoppers of this family, the Acridii, the well- 

 known musical sound is produced by rubbing the inner 

 rough surface of the femur across the ridges formed by the 

 veins of the wing-cover. 



