448 NEW AND RARE AUSTRALIAN AGRIONID.E, 



'Wings slightly petiolate; robust species with 



long legs furnished witli long bristles Group i. Argia. 



1 ' Wings more petioled; species of median 

 robustness and small species, with short 



legs and small cilia or bristles Group ii. Af/rioii. 



Species of fairly slender build; median sector 



arising weW />e/b>e nodal vein Group iii. Pseudayrion. 



Species of I'ery slender build; median sector 



arising ?'e?y o/ofe n?> <o nodal vein Group iv. Telehasis. 



Group i. Argia. 

 Absent from Australia. 



Group ii. Agrion. 

 I Quadrilateral of forewing incomplete, with basal 



J side absent Hemiphlehia. 



I Quadrilateral of forewing normal I. 



'Quadrilateral of forewing with verj' acute distal 



angle (upper side less than half ol lower) 2. 



1 { Quadrilateral of forewing with less acute distal 

 angle (upper side one-half or more than one-half 



of lower) 3. 



(Very small insects with long legs and very narrow 



\ wings. Dimorphic females Anstrocnemiii. 



[xiedium-sized insects with short legs 4. 



Very small insects with open venation (few post- 



nodals. Dimorphic females Aijriocnemis. 



Medium-sizetl insects with closer venation (more 



postnodals) Argiocnemis. 



'' Pterostii'ina i>f all wings unicolorous, female 



)/n//(0(/< spine under segment 8 Agrion. 



Pterostigina of forewing bicolorous; female with 



spine under segment 8. Dimorphic females Ischnara. 



4. 



1 J 



Group iii. Pskudagkion. 



{Basal postcostal nervule close up to level of first 

 antencjdal 1- 



Basal postcostal nervule about midway between 

 levels of the two aiitenodals 2. 



I.,arge species; superior appendages of male point- 

 ed; prothorax of female with two hooks pointing 



forward; blue colouration Caliagrion, w.g. 



Medium species; superior appendages of male 

 blunt; prothorax of female simple; red colour- 

 ation Xanlhayrion. 



