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EXTERNAL ANATOMY. 



Fig. 32. — Dorsal view of the meso-and metathorax 

 oi Melanoplus bivittatus. Original. 



iDorder of each is formed by a narrow plate, the pre- 

 scutum. Back of this is a large, convex, dark- 

 colored, glistening surface, the scutum. Behind the scutum 

 is a membranous piece upon the median line, the scutelJum. 

 The posterior margin is occupied by a long, narrow, light- 

 colored piece, the post-scutellum. 



The Wings. — The anterior or upper pair of wings (Fig. 

 33), named tegmina or wing-covers, are about as long a& 



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Fig. 33. — Tegtnina, elytra or wing-cover of Melanoplus bivittatus. Original. 



the body, beyond the posterior end of which they project. 

 The\^ are narrow and the anterior and posterior margins 

 are seen, when the wing is extended, to be nearly parallel. 

 When folded upon the bod\'^ their outer faces are vertical, 

 with the anterior margin below, and the posterior or 772- 

 ternal edges in contact along the back, the left slightly over- 

 lapping the right. Each wing-cover is a thin, transparent, 

 rather stiff plate of chitine, marked with a yellowish-brown 

 stripe. It is strengthened by a network of chitinous tubes,. 



