58 DIPTERA OF AUSTRALIA, 



S.aB. Dipt. I. p. 115, 1834 ; Zetterstedt, F. Lap. 1840; Apeilesis, 

 Macq., Dipt. Exot. suppl. I. p. 8, 1846 ; Dolichopeza, Walker, 

 Ins. Brit. III. p. 315, 1856 ; O.-Sacken, Studies, I. p. 157, 1886; 

 Bergroth, Wien. Ent. Zeit. VIII. p. 114, 1889. 



Anterior branch of second longitudinal vein entirely wanting, 

 consequently there is no rhomboid cell. Prtefurca extremely short, 

 often almost vertical. Discal cell wanting, the great cross-vein 

 situated a considerable distance before the base of the fourth 

 posterior cell. Antennas 13-jointed. Genitalia of ^ somewhat 

 incrassate, sometimes with long digitiform appendages. 



Rostrum short, without a nasus ; the latter replaced by a tuft 

 of hair. Front moderately broad ; eyes nearly round. Second 

 and third joints of palpi each longer than the first ; fourth long, 

 flagelliform. Antennae 13-jointed, usually longer in ^ than in ^ ', 

 first joint of scapus tolerably long, obconical ; second small, cyathi- 

 form ; flagellar joints cylindrical, gradually decreasing in length, 

 more or less beset with stiff hairs ; terminal joints very small. 

 Collare somewhat prolonged. Thorax convex, elongate-ovate ; 

 transverse suture distinct ; scutellum small ; metanotum convex. 

 Abdomen long, narrow, cylindrical ; ^ genital organs (PI. vi., 

 figs. 24, 25) somewhat incrassate, provided with long or short 

 digitiform appendages ; the lamella terminalis supera bidentate 

 (with a deep emargination between) at the middle ; 5 ovipositor 

 with rather short valves, the upper ones like the blade of a knife 

 (spiniform viewed from above) for about (or less than) the apical 

 half. Legs very long and slender ; tibiae with very minute spurs, 

 more distinctly visible on the hind pair ; tarsi very slender, the 

 metatarsal joint longer than the tibige. 



The venation of the wings is not subject to much variation but is 

 in some respects peculiar. The auxiliary vein ends just before the 

 inner end of the stigma. The first longitudinal vein is incurved into 

 the second before the middle of its length. The prsefurca is remark- 

 ably short, usually scarcely longer than the small cross- vein; and the 

 anterior branch of the second longitudinal vein is entirely wanting. 

 Second posterior cell usually short, with a long petiole, but in D. 



