8 BRACIIT.CEKA. 



apart, but less so than in . First longi- 



tudinal vein receiving others in it before 



its tip. Thorax and scutelluni with strong 



bristles arid pubescence ................ Apioceridae. 



Venation simple and reduced. Three pos- 



terior cells. Eyes in <$ contiguous or 



very approximate. First longitudinal vein 



never receiving others in it. Species quite 



destitute of bristles or pubescence ...... Scenopinidae, 



12. Five posterior cells. Chsetophorous species, [p. 310. 



generally very pubescent also .......... 13. 



Three or four posterior cells. Eremochsetous 



species, except BOMBYLIIDJE and some 



* 14. 



13. Vertex of head deeply sunken between the 



eyes, leaving the latter very prominent. 



Eyes in <^ always separated ............ Asilidae . 



Vertex not sunken, therefore eyes not pro- 

 minent. Eyes in cT contiguous or closely 

 approximate .......................... Tnerevidae, p. 295. 



14. Third longitudinal vein generally forked. 



Posterior cross-vein absent. Eyes in $ 

 normally contiguous in typical groups, but 

 distinctly separated in ANTHRACIN^: ; con- 

 tiguous in both sexes in Systropus. Often 

 densely furry species .................. Bombyliidae, p. 173. 



Third longitudinal vein never forked. Pos- 

 terior cross-vein present. Eyes in tf con- 

 tiguous or approximate, except rarely; but 

 in CONOPIDJE wide apart in both sexes. 

 Normally not densely furry species, except 

 in some SYRPHID^E .................... 15. 



15. Proboscis rigid and geniculate. First pos- 



terior cell closed ; antennae with apical 

 style (CONOPIN^E), or first posterior cell 

 open ; antennae with dorsal arista 

 (MYOPIN.S:) .......................... Conopidae. 



Proboscis soft. First posterior cell closed or 

 open. Antennae of very various formation. 16. 



16. First posterior cell closed. Vena spuria pre- 



sent (sometimes very faint). Eyes in both 



sexes of normal size and nature .......... Syrphidae. 



First posterior cell open. Vena spuria absent. 

 Eyes in both sexes very large (especially 

 in PIPUNCUI.IDJE) ; some of the facets 

 often enormously enlarged .............. 17. 



17. Arista dorsal, 3rd longitudinal vein well 



curved ; * apical section of 4th vein curved 

 downwards; hind tarsi never dilated .... Pipunculidae. 

 Arista apical, 3rd vein nearly straight ; apical 

 section of 4th vein curved inwards. Hind 

 tarsi dilated .......................... Platypezidae, 



18. Venation abnormal ; t no obvious cross- vein [p. 390. 



* Nearly straight in Chalarus. 



t Except in Opetia, a non-Oriental genus. 



