636 



THE PANORPOID COMPLEX, 11, 



ail illustraticju (Text-fig. 22); it belongs to the most archaic family 

 Corijdali.d<t\ of the Suborder Sialoidea. 



The arrangement of the trichiatioii differs from that of Archi- 

 panorpd only in the complete loss of the archedictyoii, and in 

 the smaller size of both macrotrichia and microtrichia. As has 

 been already pointed out, if the macrotrichia on any area of this 

 wing be plotted out, they will still show, by their positions on 

 the membi-ane, the pattern of the lost archedictyon. There is a 

 well dcA-eloped series of strong cross-veins supporting the main 



A'eiris at wide intervals. 



;V;V;>;\Y;^^ fW ^'v''*'V,;'V^\; of the wing all show macro 



^y!M^f^!y^ ^(M 'i"}\'^^U\\ trichia well developed . 

 Wm^i^^^xi^^:^^^ When we turn to the 



the 



specialised genera, we 



great advance over 



condition seen in Archi- 



hanliodes. Take, for in- 



still present abundantly all 

 over the wing, yet the mac- 

 lext-tig.-i-J. rotrichia have quite dis- 



appeared, except round the fringe of the wing, and on the ptero- 

 stigmatic area. 



An advance in a different direction is to be seen in the Sub- 

 order Raphidioidea, of which the genus Raphidia will serve as 

 an example. Here the mici-otrichia have completely disappeared, 

 but the irregular thickening of the wing-membrane remains as 



"" Portion of a main vein and surrounding membrane from the wing of 

 Archichaidiodes giittiferm Walk., to show the trichiation; ( x 100). 



