624 



THE PANORPOID COMPLEX. 111. 



fact, is only slightly removed from that of the famous systemat- 

 ise who is said to have simplified his task by throwing the 

 "varieties" out of the window. . 



Section xiii. The Venation of the Trichoptera. 

 (Text-figs. 42, 47b, 71-74.) 



Text-fig. 71 shows the venation of the Archetype of this Order. 

 The principal characters to be noted are as follows : — 



(1) The pupal wings are merotracheate, the tracheal supply 

 being generally reduced to two trachea?, which bear no relation- 

 ship to the imaginal venation. In this character, the Trichoptera 



Sc<_j£2_^*Rib 



Text-Fig.71. 

 Wings of the Archetype of the Order Trichoptera. Lettering as on p. 535. 



stand as the most highly specialised of all the Panorpoid 

 Orders . 



(2) Sc and R x are distally forked. 



(3) The branches of Rs are reduced to four in number; and 

 the apical forks so formed are destitute of cross-veins, except 

 only that between R. and R Sj which possesses a cross-vein in the 

 forewing only, as in the Rhyacophilid genus Psilochorema. 



