274 



THE WINGS OF MEMBRACID^ 



coalesces with the subcosta. (It should be remembered that vein Ri is 

 lost). The posterior half of radius, vein R4+5, separates from vein R2+3 

 very near the base of the wing, and coalesces with media for a short dis- 

 tance, after which it traverses the wing as a separate vein. A result of this 



is that while the ist cellRs of the fore 

 wing lies beyond the nodal furrow, in 

 the hind wing it reaches the base of 

 the wing; and ist cell R5 occupies a 

 similar position. 



Other features of interest in the 

 hind wing are the following: The 

 media is only three-branched as a 

 rule, but in some specimens there is 

 a small remnant of cell M2, which is 

 ordinarily crowded out by the coal- 

 escence of vein M2 and M3. The 

 first and second anal veins are 

 widely separate; and the third anal 

 vein is forked. 



In the course of the development 

 of the wing of Cicada, there is an 

 excellent illustration of the migration 

 of trachea M, which is discussed in Chapter II (p. 17). In the young 

 nymph (Fig. 270) this trachea arises from the transverse basal trachea 

 midway between the radial and cubital tracheae. In the mature nymph 

 (Fig. 272) the base of the medial trachea has reached the cubital trachea. 



Fig. 275. — The base of a hind wing of 

 an adult cicada (After C. & N.). 



(c) THE WINGS OF THE MEMBRACID.S 



The homology of the wing-veins of the Membracidas has been thoroughly 

 worked out by Funkhouser ('13), who gives in his paper many figures of 

 the tracheation of the wings of nymphs and of the venation of the wings of 

 adults. As the wings of representatives of five of the six subfamilies of this 

 family recognized by systematists are figured by him with the homologies 

 of the veins indicated in each case, comparatively little remains to be done 

 in this field. 



Only the more general features of the results obtained by Funkhouser will 

 be given here; students of this family should consult his paper for details. 



The basal connections of the tracheae of the wings. — One of the most 

 striking results of Funkhouser's studies was the demonstration of the fact 

 that the Membracids have retained the primitive condition of the basal 

 connections of the tracheas of the wings; a transverse basal trachea has not 

 been developed, the tracheae arising from two distinct main trunks; from 



