rsi;i> i;, CLASSIFICATION. 



1!) 



branches of nearly equal size. Above or behind the median vein 

 is sometimes present a short, undivided vein (/), known as the 

 vein. Next in order is the ulimr vein ( u } , which 



gives off several branches ( it', it", etc. ). The upper division of this 

 vein (o) is known as the jmxln-iar nJnar or the sitbniediaii vein. 

 Close to and parallel with it near the upper or hind margin of 

 the teamen, is the undivided <tn<il vein (a), while the uppermost 

 vein of the tegmen, also undivided, is the a.rillarii vein (x). 



in h d h d 



Fig. 9. Right tegmen of the locust, Dissosteira Carolina (L.). 

 Showing the venation. (After Saussure.) 



The tegmen is divided by these veins into three areas : The 

 or niaryiiial area (il/) forms the lower or front edge of 

 the wing cover and is bounded above and behind by the humeral 

 vein. The median or dixcoidal area (D) is much the largest and 

 lies between the humeral and posterior ulnar veins. The anal or 

 dorsal area (A') is the free margin lying along the back above and 

 behind the anal vein. The posterior end of the tegmen (A) is 

 known as the apical 



Fig. 10. Right tegmen of a locust, showing the "areas" designated in the vext. 



(After Saussure.) 



The inner or second pair of wings are joined to the rneta- 

 thorax, and when at rest lie folded beneath the tegmina. If, in a 

 fresh example, the dark colored marginal vein be pulled outward 

 or forward with a pair of forceps, it will be seen that the wing- 

 is a thin, parchment-like membrane, with a stiff front edge, which 

 is nearly straight, while the rounded outer and hind margins are 

 thin and flexible. When in flight, the wing is fully extended, its 

 upper surface being convex, Avhile its front margin is rendered 

 still more rigid by being overlapped by the internal margin of the 

 upper wing or tegmen. The numerous veins radiating from the 

 base are so arranged that their elasticity causes the wing to fold 

 upon itself like a fan as soon as its margin is released. The prin- 



