644 ON SOME REMARKABLE AUSTRALIAN LIBELLULINiE, 



very short, slightly enlarged; 3 with transverse carina one-fourth 

 from base, 3-4 slightly narrowed in middle, 5-8 slightly enlarged 

 again, 9-10 slightly narrower. Colour black; 1, a touch of pale 

 yellow on dorsum, a yellow spot on each side; 2, a yellow dorsal 

 mark, a small round spot on each side. These markings vary 

 in shape and size with the specimens. No other markings. 

 Appendages: superior 2-3 mm., sublanceolate, somewhat 

 curved, bases separate, tips pointed and curving outwards; hairy, 

 black. Inferior nearly as long, subtriangular, tip upcurved, 

 blunt and rounded; black. 



£. Total length 49 mm.; abdomen 33 mm.; forewing 44 mm.; 



16 15-16 



16-17 15-16 



Head: 



or greenish- 



hindwing 42-5 mm. Nodal Indicator 

 vertex and front brilliant metallic green 

 blue; clypeus dull shiny yellowish-brown; labrum black, a brown 

 spot on each side. T h o r ax as in £. Abdomen: 1-2 rather 

 broad, narrowing to 4 then broadening to end. Colour black; 1, 

 a yellow spot above, a pale yellow round spot on each side; 2, an 

 elongated dorsal mark and a spot on each side, yellow; 3, a similar 

 dorsal mark before the carina, a slight yellow line behind the 

 carina, on each side a small yellow basal spot and a fine yellow 

 line behind the carina; 4-6, a suspicion of a fine yellow dorsal line 

 near bases. Size of markings varies with the specimens. 

 Appendages short, 1*2 mm., very wide apart at bases, 

 straight, pointed, black. 



Bab. — Cooktown, Cairns and Kuranda, N.Q. Rare. Novem- 

 ber-February. • 



This remarkable insect has habits totally different from most 

 of the tropical Libellulince, which are sun-loving insects inhabiting 

 swamps and wide, open rivers. It is found only in the densest 

 tropical forest, inhabiting small swiftly running mountain-creeks. 

 It hawks about over the pools like an Aeschnid, but is also very 

 fond of some particular twig or branch, to which it will continually 

 return. It appears to shun sunlight, and is not difficult to 

 capture. 



It is closely allied to A. longitudinalis Selys (with which A. 

 biserialis Selys and A. Karschii Forster are synonymous), but 



