BY R. .1. TlLLYAftD. 1-1 



out of account tlie supposedly androconia-like bulbous macro- 

 trichia of the males of one particular, highly specialised genus 

 (Eiwicyhi), which clearly do not enter into the question, the 

 only scales known in the Trichoptera are very narrow, elongate, 

 lanceolate scales, with not more than four or five longitudinal 

 striae at the most. These are confined to a few isolated genera 

 in the families Sericoslomatidce and Leptoceri'Ue, but are never 

 found in any representatives of the Rhyacophilidos or Hydro 

 psychidce, which are rightly regarded as the most archaic families 

 of the Order. Nobody could possibly point to any connection 

 between the Micropteryyidce and the Trichoptera, except through 

 the Jthyaco/>hilid(e, in which the venational similarity between 

 fore- and hind wings is still to a great extent preserved. Hence 

 the fact that broad, well-developed scales are to be found on all 

 Micropteryyidce is strong evidence iti favour of their being true 

 Lepidoptera, since this Order is the only one known in which 

 scales occur universally from the lowest to the highest members 

 <>/ the Order. 



Let us then examine the types of scales to be found within 

 ihe Microplerygidce. Text- tig. 10, a shows a greatly magnified, 

 broad scale from the wing of Sabatinca inconyruella. (As in all 

 Lepidoptera, the macrotrichia in this genus show all stages from 

 a simple hair, through a flattened hair and various grades of 

 narrow to moderately wide scales, to broad scales; the latter 

 being the most highly developed, we shall study these only). The 

 principal characteristics of this scale are: its transparency, due 

 to absence of internal pigment; its regular shape, without any 

 scalloping of the distal border; the uniform delicacy of the par- 

 allel longitudinal strhe; and the absence of any sign of cross 

 striolation. This combination of characters marks off this type 

 of scale very distinctly from any other known in the whole of 

 the Lepidoptera (excluding Micropterygidce). A careful examin- 

 ation of the scales to be found in the genera Micropteryx Mne- 

 monica, and Eriocrania shows us that they all possess broad 

 scales very closely similar in type to those of Sabatinca. The 

 most generalised of all would appear to be those of Afnenionica 

 (Text-fig. 1 1, c), from which it is easy to derive the broader and 



