BY R. J. TILLYARD. 



421 



the fossil wing was considerably broader, and proljably also some- 

 what longer. The region of the quadrilateral is closely similar 

 in both, but the quadrilateral of the fossil wing is placed more 

 transversely to the wing-axis, and the lower })ortion of the arculus 

 is much more transversely placed than in Eplophlebia. The 

 quadrilateral of the fossil resembles that of the forewing of 

 Ejnophlebia (Text-fig. 12a) nmch more than it does that of the 

 hindwing (6'); but, in other respects, particularly in the strong 

 distal curvature of Cuo, the fossil wing more resembles the hind- 

 wing. A close rese)nblance to E^nophlebia is shown in the levels 

 of the origins of the branches of M, and in tlie shape and vena- 

 tion of the discoidal field and the two longitudinal areas of the 

 wing lying below it. 



The fossil, however, differs entirely from Epioph/ebia, and, 

 indeed, from all known Lestidie^ in possessing a broad and abso- 

 lutely free area between Cu and the posterior border, below the 

 quadrilateral. As the wing is excellently preserved in this 

 region, there can be no doubt about this character, which places 

 the fossil, in this respect, as more highly specialised by reduction 

 than any known Zygoptera, except only the subfamily Froto- 

 tieurince of the family Ayrionid(e. 



Where the nodus was placed, we cannot tell for certain. But, 

 if we were agreed that the comparison with Ejnophlebia would 

 hold also for this character, we might expect that it was situated 

 somewhere near the extreme distally preserved portion of the 

 fossil, i.e., considerably distad from the level of the origin of Ms. 



The comparison with Synlestfs is by no means so close, as can 

 be seen from Text-fig. 1 'Ic. The wing of Synlet^tps is exceedingly 

 narrow, and difiers from that of the fossil in having Ms arising 

 from Mg close to its origin, in the very narrow (juadrilateral, in 

 the upward arching of Cuj from the distal angle of the quadri- 

 lateral, in the consequent narrowing of the discoidal field, and in 

 the length and straightness of Cu . But, in its extreme reduc- 

 tion of the anal bridge (Ab), Synlestes shows the nearest existing 

 approach to the high specialisation seen in the fossil; and, on 

 this account, the comparison is of value. 



