402 



STUDIES IX AUSTRALIAN MECOPTERA, II. 



vein that continues the hue ut" the stem of Cu; while, in the 

 liimlwing, it must fuse with lA for a short distance, and then 

 separate from it again towards the wing-margin. 



We must now ask for definite proof that this supposition is 

 the correct one. That proof is forthcoming from two separate 

 sources, viz., the pupal wing-venation, and the imaginal wing- 

 venation. We may take these two separately. 



(1) Evidence from the papal wing-venatwii: — In the freshly 

 turned pupa, less than one day old, the fusions of veins that take 

 place in the imaginal venation are not completed, but only just 

 beginning. (The photomicrographs in Plate xliii., are from a 

 pupa at least three days old; those taken from a freshly turned 

 pupa showed the separate veins much more distinctly, but unfor- 

 tunately the negatives were partially spoilt through the use of 

 stale developer, and are not good enough to reproduce). 



Text-fig. 2. 

 Basal part of hindMing of same pupa as in Text-fig. 1, { x 43), to show the 

 radial {Rt), and median {Mt) tracheie, the approach of Cui to M, and 

 the partial fusion of Cuo with lA. 



Text-fig. 2 shows a camera-lucida drawing of the basal part of 

 the hind wing of a freshly-turned pupa. In this, the separate 

 veins Cu., and lA can be clearly seen running alongside one 

 another for some distance, and then diverging again towards the 

 wing-margin. This fixes the position of cuf dX the point already 



