Chilosia. 131 



— Eyes hairy all over; arista almost bare ; thorax with- 



out bristles 19. 



19. Antennæ brown or blackish brown 16. grossa. 



— Antennæ orange 20. 



"20. Femora pale 17. albipila. 



— Femora black except apex 18. chloris. 



2 1 . Legs black 23. impressa. 



— Legs more or less pale 22. 



22. Tarsi black, only middle tarsi a little pale at base 23. 



— Tarsi less black, middle tarsi more pale and gener- 

 ally also front or all tarsi more or less pale, at all 



events below 25. 



23. Antennæ black or blackish brown ; wings evenly tinged ; 



venter somewhat pruinose 21. gigantea. 



— Antennæ red or brownish red ; wings with the apical 

 part strongly tinged, basal part much less tinged; 



venter shining 24. 



24. Wings rather long ; antennæ small ; legs almost all 



pale-haired 25. carhonaria. 



— Wings short; antennæ larger; front femora and all 



tibiæ more black-haired 26. cijnocephala. 



25. Tibiæ quite yellow or with small or faint rings 26. 



— Tibiæ with distinct and broad rings 28. 



26. Largish species; third antennal joint orange, not longer 



than broad, arista not short 27. 



— Small species; third antennal joint brownish, longer 



than broad, arista short 30. ruralis. 



27. Third antennal joint not large; hairs on thorax 



strongly depressed; hind femora not setulose below 19. fraterna. 



— Third antennal joint large; hairs on thorax a little 



obhquely erect; hind femora distinctly setulose below 20. Bergenstammi. 



28. Epistoma pruinose, slightly hollowed below antennæ 28. velutina. 



— Epistoma not or slightly pruinose, much hollowed 



below antennæ 29. 



29. Eye-hairs whitish ; venter grey pruinose 22. proxima. 



— Eye-hairs dark above; venter shining 27. vernalis. 



As an exact description of the outline of epistoma is difficult I 

 have given figures of the heads of all species; the figures are all of 

 males, and they are drawn in absolute profile, thus the shape of the 

 antennæ and the breadth of the ey e-margins cannot be suffieiently 

 judged from them. It must also be noted that the outline of epistoma, 

 though characteristic for each species, may vary a little or sometimes 

 even more. 



