THE WINGS OF NEMOPTERIDyE 



209 



The first three longitudinal veins of the hind wing arc easily recognized 

 (Fig. 209), the costa by its marginal position, the stibcosta and radius by 



the fact that they coalesce near the 

 apex of the wing, as they do in the fore 

 wing, and also by the fact that the 

 area between them is free from cross- 

 veins as also is the case in the fore 

 wing. I term the third vein radius 

 instead of vein Ri, which is the vein 

 that coalesces with the subcosta in the fore wing, for 

 this reason: Between the third and the fourth longi- 

 tudinal veins there is a series of cross-veins; the dis- 

 tal members of this series are transverse and have the 

 appearance of ordinary cross-veins ; but the proximal 

 members are oblique, which suggest that they may be 

 branches of the third vein; it seems probable, there- 

 fore, that in the narrowing of the wing vein Ri and 

 the stem of the pectinate radial sector have been 

 brought together, and that the oblique cross-veins are 

 vestiges of the branches of the radial sector. It seems 

 proper, therefore, to term the combined veins Ri and 

 Rs as vein R. The fourth vein is probably vein M. 

 In the other members of the myrmeleonid group of 

 families, the two branches of vein M are closely parallel 

 in the hind wings, so closely parallel that the two 

 could not be expected to remain apart in the greatly 

 narrowed wing. Vein Cu is probably lost, it is usually 

 greatly reduced in the allied families. The fifth vein 



Fig. 207. — Wings of 

 Oliverina exiensa; 0, 

 oblique vein, vein 

 M3+4. 



is probably an ambient vein corresponding with the ambient vein of the 



Fore wing of Croce filipennis. 



fore wing. Considering the greatly reduced condition of the anal area 

 in the allied families it is not at all probable that this vein is an anal vein. 



