THE WINGS OF NEUROPTERA 



165 



In Megalonius the radial cuneate area is distinctly between branches of 

 vein R5; but in most cases where this area has become large it does not 

 appear to be between two forks of vein R5 but to be between the tip of vein 

 R5 and the tip of media; this is especially the case in the Ascalaphidae 

 (Fig- 157)- 



The secondary cubital fork. — In the hemerobiid and myrmeleonid 

 groups of families, vein Cui is usually more or less bent at the paint where 

 its first accessory vein, vein Cui^, is given olT and this accessary is quite 

 prominent. In this way a fork is formed that frequently appears to be the 

 chief fork of vein Cu; and, for this reason, vein Cui^ is liable to be mis- 

 taken for vein Cu2. 



In those cases where a prominent fork of cubitus is formed in this way, 

 vein Cuo separates from the stem of cubitus near the base of the wing and in 

 many cases is greatly reduced or even lost ; but in other cases this vein is 

 well presented. 



Tillyard, who recognized the nature of this fork and the position of vein 

 Cu2 in the Hemerobiidaj and in some of the Mvrmeleonida;, termed the 



Fig. 160. 



-Wings of a myrmeleonid from Persia. The base of the fore 

 wing is broken in the specimen figured. 



fork between veins Cui and Cui^ the secondary cubital fork (cuf), and that 

 between veins Cui and Cu2 the primary cubital jork (cuf) (Tillyard '16, 

 p. 291). 



The secondary cubital fork can be easily recognized in most of the 

 figures of wings illustrating the accourits of the wings of the families 

 named above. 



