86 Annals Entomological Society of America [Vol. VI, 



shown in figure 11 is about the average. In a few species^^ the 

 course is more extended, and in some" the veins do not coalesce 

 at all but run some distance apart, connected by one or more 

 cross-veins. Just before reaching the tip of the wing, however, 

 this vein separates from media to make the apical or terminal 

 cell, which is thus cell R5. The tips of both branches of radial 

 sector show signs of splitting in their tracheal condition. In 

 some cases they actually remain separate and form additional 

 cells in the wing. This is true of the species Telemonanthe 

 pulchella, Cyrtolobus vau and Smilia cameliis (see figures Nos. 

 39, 43 and 42). In the first, R2 and R3 are separate. In the 

 second, a very small cell R4 appears, showing that R4 and R5 

 have not entirely coalesced. 



In this species also, a peculiar condition of R3 is shown, the 

 end of the vein still persisting at the margin of the wing, while 

 its base has disappeared. In Smilia cameliis, R3 has not entirely 

 coalesced with R2, and extends into the cell R2+3 where it is 

 perhaps atrophying back toward its base. This means that in 

 these forms the reduction has not proceeded so far as it has in 

 the majority of the species. 



Summing up, then, radius is typically three-branched in the 

 Membracidas. Ri extends from R2+3 to subcosta. R2+3 and 

 R4-,_5 usually extend as undivided branches, with the exceptions 

 noted, to the tip of the wing, R4+5 ordinarily anastomosing for 

 a variable part of its length with M1+2. 



Media 



The course of media (Fig. 13) is quite constant. Starting 

 from the base of the wing in close proximity if not in actual 

 contact with radius, it follows a relatively straight course for 

 about two-thirds of the wing length. It represents the most 

 posterior vein of the costa-subcosta-radius-media group, and 

 its origin is intimately connected with the stem of these veins 

 (Fig. 14). In such forms as Acutalis, Micrutalis, Thelia, and 

 Carynota of the Smiliida, this close connection is not shown in 

 the adult wing. In others, as Ceresa and Stictocephala, the 

 relationship is striking, as has been referred to in the considera- 

 tion of radius. 



26. e. g., Cyrtolobus vau and Atyma castaneae. 



27. Platycotis sagittata, Enchenopa binotata, Campylenchia curvata, Centru- 

 choides perdita, and Platycenirus acuticornis. 



