238 STUDIES IN AUSTRALIAN NEUROPTKRA, iii., 



forms apart. I have called the point where the arching begins 

 the second cubital fork (cuf). It is clear that we have in the 

 hind wing a more specialised condition of Cuj than is shown in 

 the forewing, and that it is correlated with what we may call 

 the shifting of the levels of the basal portions of Ks and M 

 downwards in this wing. In other words, the distal portion of 

 Cuj still plays its part in helping to form the pseudo-cubitus, 

 even though the basal part of that vein is no longer formed from 

 Cu (as in the forewing), but from M. Finally, Cu„ in the hind- 

 wing is a simple vein leaving Cu at cuf, and connected with lA 

 basally by a cross-vein. Its actual appearance is rather as if it 

 belonged to lA than to Cu. 



Just as intra-median cells are formed between the two branches 

 of M, so intra-cnhital cells are formed between Cuj and C\x„. 

 There are three of these in the forewing, viz., icrti, icu^, icu^, 

 owing to the development of two cross-veins. In the hind- 

 wing, there is only one narrow undivided cell, icu. The cubital 

 cell (cu) is simple, and lies between the main stems of Cu and 1 A. 



Having completed our study of the radial sector, the true 

 media, and the true cubitus, we are now in a position to analyse 

 the complex veins which I have called the pseudo-media and 

 pseudo-cubitus respectively. These may be tiaced out with the 

 aid of Plate x., and the overlying transparency. 



7'^e Pseudo-media (M'). — ^In the forewing, this vein arises from 

 R near the base. Up to 7nf, it is formed by M; beyond mf, it is 

 formed by Mj above im^, then by Mj and M, united for half a 

 cell's length, then by Mj, B^, B3, B2, and B, overlapping each 

 other in turn, and finally by Bj alone. This last vein forks just 

 before reaching the wing-border. In the hindwing, the pseudo- 

 media likewise arises from R close to the base, but it is formed 

 first of all by Rs for a short distance, then by Rs and M, united, 

 then by B^ and M, united, then by B4, Bg, Bo, and Bj overlapping 

 each other in turn, and finally by Bj alone, with a distal forking 

 as in the forewing. 



The cells formed above the pseudo-media between the descend- 

 ing Manksian sectors are four in number in the forewing, three 

 in the hind (omitting the minute triangle t, which is the remnant 



