BY R. J. TILLYARD. 465 



Group iii. Pseudagrion. 



Xanthocnemis, n.g. 



Basal postcostal nervule midway between levels of the 

 two antenodalsj inferior sector of triangle reaching just he- 

 yond this nervule in forennng, just up to it in hindwing. 

 Venation fairly close, pterostigma slightly elongated, uni- 

 colorous. Inferior appendages of male much longer than 

 superiors. Female with prothorax simple and no ventral 

 apical spine on segment 8. 



Type: Xanthayrion zelam/ictini Selys (New Zealand). 



It is necessary to study this New Zealand species here in 

 conjunction with its Australian allies. A new genus is re- 

 quired for its reception, as it is clearly not congeneric with 

 Xanthagrion erythroneururn Selys, the type of the genus 

 Xanthayrion. In the form of the inferior sector of the tri- 

 angle of the forewing, it connects the group Pscudayrion with 

 the group Ayrion. In its colouration and in the form of its 

 appendages, it comes closest to Ceriagrion. 



v32. Xanthocnemis zelandica Selys. 



Xanthagi 'io)i :.elandicum Selys, "Synopsis des Agrionines," 

 Bull. Acad. Roy. de Belgique, xli., 1876, p. 232; X. anti- 

 yodaiii Selys, and A', sobri/ium Selys, loc. cit., p. 234, syn- 

 nymous with X. zclaibdicum. 



There is only one variable species included in the above 

 names. It is common all over New Zealand, and varies con- 

 siderably in size from different localities, also in colouration 

 according to age. Some of the females are very small ; one 

 of these is described by de Selys as A', antipoduin. It seems 

 nearly always to occur in company with Lesfes eolensoms 

 White, the only other known New Zealand Ayrionid. Where 

 this latter insect is largest, so also is X. zelandicuin, but I 

 think this variation in size is due as much to the season as 

 to the locality. Specimens of both these species, received 

 from Chatham Island, are exceptionally fine, and the largest 

 of the whole series. 



