, BY K. J. TILLYARD. 467 



two species from Fseudagrion and placed them in Xanthag^ 

 rion, with which they agree in the form of the male append- 

 ages and female prothorax. But this arrangement ignores 

 the fundamental venational difterences, which, it seems to 

 me, are of a higher order than the sexual characters men- 

 tioned above. Also the build, size, and colour-scheme of 

 these two species are all essentially different from those of X. 

 erythromurum. Nevertheless, Dr. Ris was right to em- 

 phasise the fact that these two insects do not belong to Pstud- 

 ayrioii, from which they differ, not only in the already men- 

 tioned sex-characters, but in possessing a less elongated ab- 

 domen, and rather broader wings — in fact, they are more 

 of the Agnon-huild, and probably represent one of the first 

 asthenogenetic offshoots from that type. 



34. AUSTROAGRION CYANE SclyS, loc. cit., p. 218. 



35. AusTROAGRiON ccEKULEUM Tillyard. 



Fseudagrion coeruleum Tillyard, These Proceedings, 1907, 

 xxxii., p. 739. 



The appendages of the males of these two closely allied 

 species, are figured in Plate xlviii., (figs. 27-30). Owing to 

 the matted hairs surrounding the superior appendages, they 

 are most difficult to draw. This has caused a slight error in 

 the outline sketch of the superior appendages of .-i . coeruleum 

 (profile view), as given by Dr. Ris. The appendage is not 

 bluntly truncate, but actually rather pointed, the point being 

 inclined somewhat downwards (upwards in A. cyaiie). On 

 the upper surface, is a thick mat of hairs jutting out about 

 midway, and curling over towards the tip ; this gives the 

 appearance of a truncate outline. The differences for the 

 two species are clearly shown in the diagrams. They are 

 closely allied, geminate species, separated by the desert- 

 barrier of South-Central Australia. 



Austroagrion cyane Selys, is a very variable species, attain-- 

 ing its highest development in Tasmania and Victoria, where 



43 



