NO. 2 THORACIC MECHANISM OF A GRASSHOPPER SNODGRASS 85 



tween the two wing areas takes place along the anal fold (figs. 45 A, 

 50 A, AF), and is produced mechanical!}^ during the flexion of the 

 wing. The broad hind wings are folded in a complicated manner, to 



C Sc R M I 



JtI 



Pra 



2Cu '^A iCu iX 



A 



Sc^ R+M iCu 2Cu M Re C Ri 



\ \ \ \ \ \ / / 



Fig. 45. — The wings and wing veins of Dissosteira. 

 A, fore wing, or tegmen. B, hind wing. A, anal veins, anal area of wing- 

 J A first primary anal vein ; yA, seventh primary anal ; C, costa ; iCu, first 

 cubitus; 2Cu, second cubitus; /, intercalary vein; /, /, secondary anal veins of 

 first anal plait; k, first concave anal vein; Ju, jugal area of wing; /, second con- 

 cave anal vein; M, media; Pra. preanal area of wing; q, basal support of anal 

 veins ; R, radius ; Ri, first branch of radius ; Rs, radial sector ; r, first anal plait 

 of wing ; R-\- M, united shafts of radius and media ; Sc, subcosta ; P'D, vena 

 dividens. 



be described later, and when fully flexed are concealed beneath the 

 overlying tegmina (fig. 50 A). 



The area of an insect's wing presents usually three well-defined 

 regions, namely, a preanal region, an anal region, and a small, pos- 



