BY R. J. llLLYARD. 



403 



selected. The upwardly arching branch above ctif is seen to be 

 connected witli the media by a i<hort crobS-rcAn, descending from 

 the latter vein. In this pupal tracheation, then, the line of the 

 median stem is not continued by Cui, but by the true media; it 

 is only a rearrangement of the positions of these parts in the 

 imaginal venation that brings Cuj into the position of continuing 

 the line of M.^ 



The case for the forewing is still simpler. Here there is no 

 fusion of Cuo with lA, and the parts of the cubitus can be seen 

 to be quite separate from both M and lA. 



{'2) Evidence from the imaginal venation: — The evidence that I 

 propose to bring forward 

 here is of quite a novel 

 kind, and does not ap- 

 pear to have been used 

 hitherto in any research 

 upon wing- venation; yet 

 it is of the utmost vahie. 



In the wings of all 



Holometabolous Insects, 



two kinds of hairs or j /-x- 



setyy are developed. \ L-^L_^___ 2A. 



These I have called ma- 



crotrichia and mic7'otri- Text-tig.o. 



chia respectively, t The Part of the imaginal venation of the forewing 

 former are in most ^^ Chorista australis Kkig, in the region of 

 ..,-,, ,1 the cubital fork (c?//), to show distribution 



cases, restricted to the „ ^, - • i- / .,^\ i 4-\ ■ *- ^ 



' of the niacrotnchia; ( x 27) : k, the ponit at 



veins; the latter are which Cui has fused with M; .r, cross- veins. 

 spread indiscriminately, 



and much more abundantly, over the whole of the w ing. In the 

 Mecoptera, the macrotrichia are found upon all the main veins 

 and their branches, but never wpott the true cross-veins. Hence 



'"■ Compare the somewhat analogous condition in the forewing of Myr- 

 meleontidte, where Cuia captures Mo close to its origin. 



t "Mesozoic Insects of Queensland, No.l.'' These Proceedings, 1917, 

 xHi., Part 1, p. 195. 



