13G 



REPORT OF STATE GEOLOGIST. 



(d), is known as the "discoidal vein," its branches being designated 

 as (d', d" ), etc. The fourth or ''median vein" (n) is much smaller 

 and soon divides into branches of nearly equal size. Above or be- 

 hind the median vein is sometimes present a short, undivided vein 



\r M V t u y 



Fig. 10. Right tegmin.a of the locust. Disionteira fnri'lina (L.) Showing the venation. 



(After Snus8uie.) 



(i), known as the ^'intcrcalav}- vein." Xext in order is the "idiiar 

 vein" (u), which gives oil' several branches (u', u" , etc.). The 

 upper division of this vein (o) is known as the "posterior ulnar" or 

 the "sub-median vein." Close to and parallel with it near Ihc upper 

 or hind margin of the wing cover is the undivided anal vein (a); 

 while the uppermost vein of the wing cover, also undivided, is the 

 "a.xillarv vein" (x). 



The tegmina is divided by these veins into three areas: The "'cos- 

 tal" or "marginal area" (M) forms the lower or front edge of the 

 wing cover and is bounded above and behind bv the luuneral vein. 



oA 



Fig. 11. Right teguiina of a locust, showing the "areas" designated in the te.xt. 

 (Alter Saussure.) 



The '"jnedian'' or "discoidal area" (U) is much the largest and lies 

 between the humeral and posterior ulnar veins. The "anal" or "dor- 

 sal area" (X) is the free margin lying ahuig the btuk ahovi' and he- 

 hind the anal vein. The posterior end of tlie wing cover (A) is 

 known as the "apical margin." 



The inner or second })air of wings are joined lo the nu'tathornx, 

 and when at rest lie folded beneath the tegmina. U', in a I'resh ex- 

 ample, the dark colored marginal vein be ])ulled outward or forward 

 with a pair of toi'ccps, it will I)e seen that the wing is a tliin, parch- 

 nu'ut-like mendjrane, with a still' front edge, which is nearly straight, 

 while the rounded outer and hind margins are thin and flexible. 

 A\'1kmi in flight, the wing is fully extended, its upper surface being 



