nv K. .r. Tii.LVARi). 373 



bronze-trreen, touched with brown on shoulders; underside brown, 

 tiotum brown, wing-bases hairy, scuta and scutella pale straw-colour. 

 Legs black, profemora and underside of metafemora brown. A b - 

 d o m e n : 1-2 enlarged, 3 somewhat pinched; rest of abdomen con- 

 siderably dilated, 4-7 very wide, 8-10 tapering rapidly. Colour : 

 1-2 dark brown, each with a conspicuous transverse apical band 

 of cream-colour; 3-10 dark metallic greenish-black above, sides 

 rich orange except near sutures, the orange patches being only 

 slightly widest near middle of each segment; 3-9 with a narrow, 

 transverse, apical band of cream-colour; 10, apical half orange, 

 with a small spine on each side. Appendages: siiperior 

 2 mm., narrow curved sublanceolate, approaching each other so 

 as nearly to touch at two-thirds of their length, the apical one- 

 thirds strongly divergent and somewhat depressed, tips rounded; 

 colour black, with a few small hairs. Inferior 1 -5 mm., sub- 

 triangular, tip slightly upcurved; pale brown bordered with 

 black. 



$. Ditters from male as follows : metallic colour of front much 

 duller, sometimes brownish, thoi'ax less metallic. A 1) d o m e n 

 broad, almost cylindrical, the orange and metallic colouration 

 duller; 1 with basal thii'd black, the rest orange. Vulvar lamina 

 with two short subtriangular projections from end of segment 8. 

 Appendages 23 mm., rather thick, hairy, dark brown, outer 

 edge straight, inner edge distinctly curved, tips slightly pointed. 



Hab. — Tasmania : abundant on the lagoon near Cressy, also 

 fairly common on the Macquai-ie River( January, 19U9). Victoria: 

 Gisborne, 1 9(December, 1908). 



Types: (J9. Coll. Selys(four specimens from N. S.Wales). 

 The fine series from Cressy has been distributed by me, as far 

 as possible, amongst all the modern collections; my own series 

 contains 22 males and 13 females. 



An interesting fact concerning this insect is that it is 

 undoubtedly being rapidly exterminated from the Tasmanian 

 rivers by the introduced English trout. I am quite certain that 

 it scarcely ever breeds in the rivers now, and that the specimens 

 that fly on the Macquarie River are the overflow of the abundant 

 swarm from the lagoons. On the line Nortli and South Esk 



