(348 



THE PANORPOID COMPLEX, 11, 



all '•iKJii-aculeate' funiisinto one Suborder would be as unnatural 

 a grouping as it would also be in the Order Planipennia. 



The most striking character of the Order Lepidoptera is the 

 specialisation of the niacrotrichia as scales, throughout the whole 

 Order, from the lowest to the highest forms. Although, as we 

 have already seen, scales are to be found on the wings of other 

 Orders of Holometabola (Planipennia, Diptera and Trichoptera), 

 vet in each case they only occur spasmodically, as cases of high 

 specialisation in one or more isolated groups. But, in the Lepi- 

 tloptera, the scale-bearing habit is an ordinal character, the only 

 exceptions to which can be traced definitely to retrogression 

 (e.^., in the Fsyrhid(t'). 



%.:.Q.:. 



V . 



Text-%.32. 

 .Sniall |)ortion of a main vein and adjacent menilnane from tlie forewing of 

 rrofof/i«:ora pefrosemfi Meyr., (8. Africa), to sliow the trichiation; 

 ( X 200 1. (From a partiall}^ descaled specimen). 



In order to establish the proof that these scales are modified 

 macrotrichia, it is only necessary for us to study such an archaic 

 type as FrofotJwora''' (Text-fig. 3 2), in which the macrotrichia 

 upon the veins remain in their original state of somewdiat flexible 

 hairs, while the arrangement of the bases of insertion of the 

 scales upon the membrane can be seen to correspond wdth the 

 pattern of an original archedictyon. It will also be noticed that 



* For the supply of material of this rare genus, I have to thank Dr. 

 Peringuey, Director of the South African Museum, Capetown. 



