1 18 MORPHOLOGY, ETC., OF THE MICIIOPTERYGID^, i., 



position; and hence we may say that R n though very variable 

 in the hindwing of this genus, is always more or less specialised 

 in its formation. 



Meyrick figures the hindwings of both S. chrysaryyra and S. 

 inconyruella with a complete and normally placed K,, and omits 

 Sc 2 from the hindwing of the former species (6, Plate, figs. 11, 12). 

 If these figures are correct, then the variability in the structure 

 of Rj in the hindwing of Sabatinca must be very great. I have, 

 however, mounted and studied a considerable number of hind- 

 wings of this genus, and in none of them have I seen anything 

 comparable with what Meyrick figures. 



Reviewing the above evidence, we see that the four genera 

 Sabatinca, Micropteryx, Mnemonica, and Eriocrania are closely 

 allied as regards their wing-venation. Sabatinca is perhaps the 

 most archaic, but cannot be the direct ancestor of Micropteryx, 

 on account of the specialisation of R 2 in the hindwing. Both 

 Sabatinca and Micropteryx, again, are more specialised than the 

 other two on account of their more symmetrical, sharply-pointed 

 wings; and hence they can neither of them be the direct ancestor 

 of the Eriocraniince. Mnemonica is older than Sabatinca, not 

 only in the shape of its wings, but also in having Rj forked in 

 both wings; but it has mostly lost the original dichotomic 

 arrangement of the branches of Rs - a very important specialisa- 

 tion—and has one branch of Rs absent from the hindwing. 

 Eriocrania may well be a direct derivative from Mnemonica, by 

 loss of one branch of Rs in the forewing also. 



The remaining genus, Mnesarchcea, (Text-fig. 9) presents a 

 remarkable venational problem. In both wings, one vein has 

 been lost; and a careful examination of the courses of the remain- 

 ing veins, in the two species M. paracosma Meyr., and M hama 

 delpha Meyr., shows us at once that this vein is the same as the 

 one lost in Eriocrania; in other words, R2+3 is an unbranched 

 vein in this genus. In my specimens of the type species para- 

 cosma, the vein M 3 is quite clearly to be seen, still attached to 

 M 2 by a definite stalk, as well as to K s by the cross-vein r-m. 

 Meyrick, however, figures the forewing of this species with M, 

 directly attached to Rj, and with no attachment at all to M„. 



