248 FOSSIL INSECT WING, ORDER PARAMECOPTERA, 



from a common ancestor ivhich was itself derived from the Para- 

 m*coptera. It is quite clear, of course, that if we had the whole 

 fossil record hefore us, we could not say definitely where the 

 Paramecoptera ended and the Trichoptera and Lepidoptera 

 began. It is also quite clear that Belmontia itself could undergo 

 considerable further reduction, and still be legitimately regarded 

 as the true ancestral type from which both these Orders have 

 been derived. Our chief satisfaction in the discovery of the new 

 fossil should be, I think, that we have found a type far enough 

 back in point of evolution, as well as in point of time, to indicate 

 not only the true line of descent of these two Orders, but also 

 their true relationship with the much older Order Mecoptera and 

 its other near allies. 



(iii.) Affinity with the Paratrichoptera. 



We may now turn from the consideration of the Lepidoptera, 

 and examine the relationship of Belmontia with the group of 

 Trichopterous-like fossil insects which I have termed Paratri- 

 ehoptera(7), from the Upper Trias of Ipswich. We do not know 

 the condition of the arculus in any of the four known genera of 

 this Order, the basal part of the wing being not clearly enough 

 preserved for this purpose, even in the beautiful wing of Aristo- 

 psyche. The vein that I have called Cu, in that genus appears 

 to come off directly from near the base of M. Hence it is either 

 the true Cu,, attached to M as in most Mecoptera; or it may be 

 attached by means of a very specialised arculus, whose junction 

 with the true basal piece of Cu, is not clearly visible in the fossil; 

 or it may even be not Cu, at all, but the vein M 6 complete, 

 before its fusion with Cu, is accomplished. Until a more perfect 

 representative of this Order is forthcoming, it is useless to argue 

 as to whether the Paratrichoptera can be derived from the Para- 

 mecoptera. Hut we should note that Aristopsyche has the 

 remains of a true costal vein, separate from the costal border of 

 the wing, and that it has more veinlets in the costal space than 

 are to be found in the same area of Belmontia. In these char- 

 acters, Aristopsyche is more archaic than Belmontia; while in the 

 lack of the distal forking of the supposed Cu,, it is less so. 



