BY K. .1. TILLYAKb. 769 



I believe that a natural division t)f the Australian species is 

 possible, without attempting to make use of characters so essen- 

 tially variable as the cross-venation. Anyone who has studied 

 these insects at all fully will be at once struck with the very 

 great difference exhibited between Psychojyds illidyei Froggatt, 

 and all the other species. This may be seen at once by com- 

 paring Plate Ixxvii., fig.i, with Text-fig. 1 and Plate Ixxviii., fig. 

 10. Apart from its much greater size, Ps. illidgei differs from 

 all the other species by the shape of the wings, in which (but 

 more especially in the forewing), the dorsal margin is strongly 

 exca\ated, so that the torn us projects very prominently beyond 

 the rest of the wing-area. This species is also unique in possess- 

 ing raised or embossed areas upon the forewing. Further, there 

 is a gj-eat difference in the venation, in that the branches of the 

 radial sector are far more numerous and closely set in this species 

 than in any other, giving the wings the appearance of having 

 been made from spun silk or some other fine material. Finally, 

 if we examine the condition of the median vein, we shall find 

 that it has from four to six branches within the disc; whereas, 

 in all the other species, it is only two-branched. These differ- 

 ences are so striking, that I have no hesitation in separating out 

 Fd. iUirhjei from the other species of the genus, to form the type 

 of a new genus Megajysychops, whose full definition will be found 

 below. 



All the Australian species left over in the genus Psychopsis 

 agree in possessing a moderate number of branches of the radial 

 sector, in having a hindwing about two-thirds as wide as the 

 fore, and with a very characteristic, dark, round spot upon it, 

 towards the apex. But I have, in my collection, a small i\e,\w 

 species, in which the hindwing is much narrower, being only 

 about half as wide as the forewing, and the dark spot is absent. 

 Though these characters do not separate this species so distinctly 

 from the rest as do those of Ps. illidyei, yet they have the merit 

 of being obviously constants. Hence I propose to describe this 

 new species under a new generic name, P sychopsella, of which it 

 will form the type. The full definition of this genus is given 

 below. 



