BY R. J. TILLYARD. 481 



formed by Karsch into a separate subfamily, Zyxommina?. A 

 first examination of the insect would suggest that it belongs to 

 the Corduliince, since it has the general fades of that subfamily. 

 But the eyes, both in shape and in their extreme contiguity, as 

 well as the wing-neuration, demand that it should be placed 

 somewhere at the head of the Libellulinse, close to Tholymis and 

 Pantala. This seems to me its proper position; nor is there any 

 need for a new subfamily to contain it, unless we are to split up 

 the Libellulinse altogether into half-a-dozen or more subfamilies. 



Four species of this genus are known, one from West Africa, 

 and three from India and East Indies. Z. petiolatum is found in 

 India, Ceylon, and the East Indies. In Australia it is evidently 

 extremely rare. I found it in only one spot, some ten miles out 

 of Cairns, flying swiftly up and down a creek in the guava scrub, 

 at dusk. It often hovers quite motionless in the air for a long 

 time, and when flying, almost skims the surface of the water. I 

 took about half-a-dozen males and two or three females. 



The following is a description of this remarkable insect, made 

 from the freshly killed specimens : — g. Total length, 49 mm.; 

 abdomen, 37 mm.; wings, fore 32 mm., hind 32*5 mm. Wings 

 completely shaded (in the mature insect) with dull yellowish- 

 brown; tips from pterostigma outwards, fuscous; bases of hind 

 wings very slightly saffroned; hindwings slightly longer than 

 forewings, anal border rounded. Pterostigma 3 mm., brown. 

 Membranule, fore, small, brown; hind, 2-5 mm., rather broad, 

 dull brown on a black nervure. Nodal Indicator till 7-8 last 

 antenodal of forewings, and first two or three post || 8 8-9modaLs 

 of all wing not continuous. Head: Vertex small, hairy, tuberclec), 

 black; ocelli central, brilliant; other two smaller, brown; antennm 

 2 mm., brown; eyes dark green in the living insect, dark brown 

 in the dried specimen. Front cleft medially, dark brown above 

 with greyish hairs, dull dirty yellowish-grey on sides and below; 

 clypeus dull dirty yellowish-grey; labrum brown ; labium and 

 mandibles pale dirty yellowish-grey. Thorax : Prothorax pale 

 brown. Meso- and metathorax dark brown, almost black on 

 shoulders; sides dirty brown shading to dirty greyish-brown 

 34 



