130 Syrphidae. 



5. Thorax coarsely punctate, slightly shining, with de- 

 pressed greyish and black pubescence (i. 



— Thorax finely punctate, shining, with more or less 



erect, all yellow pubescence 7. 



6. Wings strongly brownish ; thorax very coarsely punctate 3. nigripes. 



— Wings almost colourless ; thorax less coarsely punctate 4. vicina. 



7. Epistoma almost not pruinose; thorax and abdomen 

 not densely punctate and not densely haired ; the 



hairs on thorax short 2. antiqua. 



— Epistoma pruinose ; thorax and abdomen densely punc- 

 tate and very densely haired ; the hairs on thorax 



longer, especially anteriorly 5. pubera. 



8. Epistoma without hairs ; sculellum with distinct marg- 

 inal bristles 9. 



— Epistoma with slight hairs ; scutellum without marginal 



bristles 14. intonsa. 



9. Arista distinctly pubescent; tip of scutellum yellowish. ... 10. 



— Arista slightly pubescent or almost bare ; tip of scu- 

 tellum not yellowish 12. 



1 0. Central facial knob very broad ; legs extensively pale .... 11. 



— Central facial knob not specially broad; legs more 

 darkened; antennæ dark 8. longula. 



1 1 . Third antennal joint smallish, brown or reddish brown ; 

 thorax fmely punctate; posterior tarsi with third and 



fourth joints broad 6. scutellata. 



— Third antennal joint large, orange; thorax more 

 coarsely punctate; posterior tarsi not with third and 



fourth joints broad 7. soror. 



12. Third antennal joint smallish, blackish 29. mutabilis. 



— Third antennal joint very large, orange 9. pagana. 



13. Epistoma with hairs on the sides 14. 



— Epistoma without hairs 17. 



14. No thoracai or scutellar marginal bristles, pubescence 

 long, tricolorous on abdomen; wings with a black 



band or blotch on the middle 10. illustrata. 



— Thoracai and scutellar marginal bristles present; 

 pubescence short, not tricolourous on abdomen ; wings 

 without band or blotch 15. 



1 5. Legs black 11. variabilis. 



— Legs more or less yellowish 16. 



16. Antennæ dark; scutellar marginal bristles very short; 



tibiæ not pale at apex 12. honesta. 



— Antennæ more or less reddish; scutellar marginal 



bristles longer; anterior tibiæ pale at apex 13. frontalis. 



17. Scutellum without marginal bristles, and likewise post- 



alar cailus (except in canicularis) . 18. 



— Scutellum with marginal bristles, when indistinct at 



all events postalar cailus with bristles 21. 



18. Eyes hairy only on the upper part; arista distinctly 

 pubescent; thorax with some bristles at the sides; 



antennæ brown or brownish red 15. canicularis. 



