DIPTERA. 



bb. Mesonotum not thickly yellow-pilose ; second abdominal 

 segment not so marked. 

 c. Thorax wholly black ; wings hyaline, with narrow dark 

 brown clouds on the cross-veins, and similarly coloured 

 spots in the marginal and submarginal cells .... 8. Sp. 

 cc. "Wings not so marked. 



d. Legs black, with the firstthree tarsal joints light yellow. 

 e. Wings distinctly f asciate ; pleurse with one or two 



yellow spots 6. picta, Wiedem. 



ee. Wings indistinctly fasciate ; pleurse with five or six 



yellow spots 7. fasciata, Macq. 



dd. Legs black, with the baseof the tibiae yellowish . . 5. avida, O. S. 

 aa. Margin of the scutellum with distinct bristles. 



/. Wholly deep metallic blue species ; face short, 



deeply concave below the antennae 13. ubesa, Fabr. 



ff More or less yellow species ; face gently concave 

 below the antennse. 

 g. Face without median black stripe; abdomen 



reddish-yellow 12. mellea, Jaenn. 



gg. Face with a median black stripe ; abdomen 

 chiefly black. 



h. Mesonotum thickly yellow-pilose . . . . 11. casariata, sp. n. 

 hh. Mesonotum thinly pilose; abdomidal seg- 



ments 2-4 banded 9. fraudulenla, sp. n. 



C. Second longitudinal vein regular ; scutellum without bristles ; no 



prescutellar row of bristles ; wholly deep metallic species. 

 «. Face perpendicular and nearly straight in profile ; wings pure 



hyaline 15. comstocki, Willist. 



aa. Face concave and tuberculated ; basal costal half of the wings 



deep brown ; large species 14. esuriens, Fabr. 



D. Second longitudinal vein regular; scutellum witli bristles; a 



prescutellar row of bristles present ; face concave and tuber- 

 culate. 



a. Epistoma strongly projecting, porrect, and acutely conical ; 



third antennal joint markedly emarginate above 16. haagi, Jaenn. 



aa. Epistoma produced but moderately or not all forwards ; third 

 antennal joint feebly or not at all emarginate. 

 b. Face with a brown median stripe ; abdomen light yellow, 



with black bands 20. comastes, sp. n. 



bb. Face without median stripe. 



c. Wings without distinct spots ; abdomen chiefly or wholly 

 deep black or violet. 



d. Wings pure hyaline 19. chatophora, Willist. 



dd. Wings infuscate ; abdomen deep violet, with the base 



light yellow 21. amethystina, Bigot. 



