BY R. J. TILLYARD. 667 



Text-fig. 90 shows the traeheation in the wings of a freshly 

 turned pupa of Wingia. These wings are very delicate, and, 

 being somewhat small, require very careful dissection. Later 

 in pupal life, they become very tough, and can be easily re- 

 moved from their sheaths without any damage. The late pupal 

 wing can be cleared in chloro-phenol, the tracheae remaining un- 

 shrivelled for some time, even under this strong reagent. 



The points to be noted in the early pupal wings are as fol- 

 lows : — 



( 1 ) Trachea M is far removed from trachea Cu at its origin, 

 and belongs properly to the costo-radial group. 



(2) The three anal tracheae come off close together in a 

 bunch, far removed from Cu. 



(3) All the branch tracheae are split back very far towards 

 the bases of the main tracheae to which they belong, so that the 

 actual point of origin of any given branch trachea is situated 

 very much further basad than is the true fork which corre- 

 sponds to it in the imaginal venation. (This character is to 

 be noted in all Lepidopterous pupae, to a greater or less ex- 

 tent, but is particularly marked here . ) 



(4) R2+3 divides near the middle of the wing, R 4+5 much 

 further distad. In the Hepialidae, the reverse is the case, as 

 also in the Trichoptera. 



(5) M and Cu 2 are complete tracheae, not reduced in either 

 wing . 



(6) In forewing, there is a kink in the course of 1A, in- 

 dicating the point at which, in the imaginal venation, 2A will 

 loop up with 1A. But trachea 2A does not reach this point, as 

 it stops considerably short of it. 



(7) In hindwing, Rs is a simple trachea, and Sc is much 

 reduced, its distal end lying close along-side R lt 



(8) In hindwing, 1A makes a large upward loop, so as to 

 come into contact with Cu 2 not far from its origin. (Compare 

 the condition of these two tracheae in Hepialidae.) 



(9) In hindwing, trachea 2 A is aborted, the course of the 

 vein in the imaginal wing being indicated only by a pale band, 

 represented by a dotted line in Text-fig. 90. 



In Text-fig. 90, I have indicated by dotted lines the positions 

 of M 5 , the distal closure of the basal cell, and the completion 

 of the looping-up of 2A on to 1A, although these are not 

 clearly apparent until the pupa is more than a day old. They 



