THE WINGS OF MEMBRA CID^ 



279 



latter branches. Here it turns cephalad and runs across to subcosta where 

 it again turns outward and closely parallels subcosta for some distance in 

 its course toward the tip of the wing. The sharp turns made by the trachea 

 in following this course (Fig. 283) are remarkable, and in the veins which 

 enclose this region of the wing, the bridge from the radial sector to subcosta 

 gives every appearance of a cross- vein." 



From the above it is evident that the two principal branches of radius 

 represent the radial sector and are veins R2+3 and R4+.^ respectively. 

 Although the tracheae that precede these branches are represented simple 

 on the figures copied here, Funk- ^ 



houser states that both of them 

 "showed constant and unmistak- 

 able signs of further subdivision 

 at their tips," and in a few cases 

 he found veins corresponding to 

 these subdivisions; thus in 7>/a- 

 monanthe pitlchella and in Smilia 

 camelus, veins R2 and R3 end 

 separately. 



The media. — The medial tra- 

 chea is easily recognized by its 

 position in the costo-radial group 

 of trachea (Fig. 276) ; thisposition 

 being that of the radial trachea in the Plecoptera and in those cockroaches 

 in which a transverse basal trachea has not been developed, and which was 

 adopted in the construction of the hypothetical type (Fig. 278). 



In the Membracidae, media is usually reduced to a two-branched condi- 

 tion; and in most members of the family vein M1+2 unites with vein R4+5 

 for a distance (Fig. 268). 



In a few genera media is three-branched ; as in Xantholobus trilineatiis, 

 where vein M1+2 is forked, and in Archasia belfragci, where vein M3+4 is 

 forked. 



The cubitus. — An examination of the tracheation of the wings of n^^mphs 

 shows that the first member of the cubito-anal group of trachese is a large 

 branched trachea which at first sight appears to be the cubital trachea 

 (Fig. 276 and 277); bvit the branching of this trachea occurs proximad of 

 what becomes the hinge line of the adult wing; so that the two branches 

 represent two distinct veins of the adult wing, i. e. veins Cu and ist A. 

 This condition is almost identical with what exists in the cicada (Fig. 270, 

 p. 271). 



The recognition of cubitus in the Membracidae is more difficult than in 

 the cicada, because in the Membracidae this vein is reduced to an un- 

 branched condition. But Funkhouser found that the cubital trachea is 



Fig. 283. — Highly magnified portion of 



fore wing of a nymph of Vanduzea 



arquata showing the region of 



trachea Ri. 



