THE WINGS OF RAPHIDIID^ 



173 



In Raphidia adnixa the forking of vein R4+5 is in about the same posi- 

 tion as in hwcellia, but the tips of one or of both of the veins R4 and R5 are 

 split; vein R3 is split back a considerable distance; and the forking of vein 

 R2 has progressed so far that what is probabh' a definitive accessor}' vein, 

 vein R2a, has been developed. This development of a definitive accessory 

 vein upon vein R2 is of considerable interest as it indicates the beginning of 

 the development of a pectinate radial sector. 



In certain other species of Raphidia, the wings of which are figured by 

 Albarda ('91), the forks of veins R2+3 and R4+5 are more nearly opposite 

 than they are in the wings figured here. 



Returning to the wings of Raphidia adnixa, we find that the tips of all of 

 the branches of media are split and that the number of accessor}' veins 

 borne by vein Cui is greater than in Inocellia. In fore wing of the Raphidia, 

 vein Cui not only anastomoses with media at its base but there is also an 

 anastomosis of this vein with vein M3+4. The fact of this last anastomosis 

 is made evident by comparison with the hind wing where the two veins are 

 connected by a short cross-vein. In the hind wing veins Cu2 and ist A 

 anastomose along the region where they are closely parallel in Inocellia. 



Fig. 168. — Wings of Raphidia adnixa. 



An obvious distinction between Inocellia and Raphidia, pointed^ out by 

 Albarda ('91), is that in Raphidia the pterostigma is traversed by a branch 

 of vein Ri, which is lacking in Inocellia. 



In both genera the cross-veins are greatly reduced in number; and there is 

 a marked tendency towards the alignment of those in the outer part of the 

 wing in a gradate series ; this is well shown in the hind wing of Raphidia adnixa. 



