62 



EXTERNAL ANATOMY, 



anterior angles of the episternal regions of the second, third, 

 fourth, fifth, sixth, seventh and eighth segments are the 

 openings of the spiracles, sp. As the structure of the terminal 

 segments differs considerabl}^ according to the sex of the in- 

 dividual, both males and females should be studied and com- 

 pared. The females are usually more abundant than the 

 males, and may be recognized by the presence of the strong, 

 blunt, forceps-like ovipositor, which forms the posterior ex- 

 tremity of the body. 



In the ventral view, (C), of the abdomen of the nsa/e, (Fig. 

 38), nine distinct movable sterna are visible; they are 



Fig. 38 — Abdomen of male Melanopl-js bivittains. A. lateral view; B, dorsal 

 view; C, ventral view. Original. 



nearly equal in length and similar in shape. Posterior 

 to the ninth sternum, the ventral surface of the bodv is oc- 

 cupied by a large spoon-shaped sUi5-o-en/Ya//?7ate, (g pi), con- 

 vex below and concave above. Above this plate is a large 

 chamber open behind, and at the sides the genital chamber. 

 On the lower floor of this chamber, and therefore on the 

 upper surface of the sub-genital plate, is the male reproduc- 

 tive orifice. 



In a dorsal view, (Bj , the terga are substantially alike as far 

 as the eighth. The eighth is a little shorter than the seventh. 

 The ninth is only about one-fifth as long as the eighth, and 



