202 A. L. MELANDER. 



TACHYDROMIIN^. 



5. A portion of the anal cell present Platypalpus Macquart. 



Anal cell wholly wanting 6. 



6. Second basal cell much shorter than the first; all the femora greatly thick- 



ened ; thick-set bristly species with small eyes. 



Coloboiieura gen. nov. 

 Not such flies 7. 



7. Arista terminal 8. 



Arista dorsal or subdorsal 10. 



8. Front femora greatly thickened ; wings sometimes variegated ; front coxse 



lengthened Tachydromia Meigeu. 



Otherwise 9. 



9. Last antenna! joint elongate, conical Elaphropeza Macquart. 



Last joint short, oval, or round Drapetis Meigen. 



10. Proboscis short, vertical ; palpi broad ; front generally of an equal breadth ; 



hypopygium large.. Stilpon Loew. 



Palpi narrow, slender; hypopygium not greatly enlarged. 



Plioneutisca Loew. 



HEMERODROMIIN^. 



11. Third longitudinal vein simple, discal cell present, emitting three apical 



veins 12. 



Third vein forked 15. 



12. Legs very slender, nowheres thickened 13. 



Front femora robust; eyes separated ; basal cells long, anal cross-vein perpen- 

 dicular Liitanomy ia gen. nov. 



13. Third antennal joint long, acuminate, proboscis incurved. 



Syiiainphotera bicolor Loew. 

 Third antennal joint short ovate ; proboscis vertical 14. 



14. Eyes of the male nearly contiguous ; hypopygium swollen, proboscis longer 



than the head ; anal and second basal cells subequal (European species). 



Sciodromia Haliday. 



Eyes separated ; hypopygium small; proboscis short; anal cell shorter than 



the second basal Oreotlialia gen. nov. 



15. Head more or less flattened and horizontal ; front femora greatly thickened, 



bristly beneath, about equalling their coxEe; when the discal cell is 

 present it is narrow, its outer boundary short, nearly perpendicular, 

 and generally emitting two veins to the margin, of which the anterior 

 is furcate, or in some cases three posterior veins are present. 



Hetnerodromia Meigeu (sens. lat.). 



Front coxse short, femora never thickened, not evidently spinose beneath ; 



discal cell always present, moderately large, often pointed apical]y...l6. 



16. Scutellum hairy ; discal cell emitting only two veins, of which the anterior 



is furcate Roederiodes Coquillett. 



Scutellum bare, except for the marginal bristles ; discal cell sending three 

 veins to the wing margin 17. 



17. Head lengthened, reaching forward; veins two and three undulating; arista 



very long Ardoptera Macquart, 



Head nearly vertical; arista moderate Clinocera Meigen (sens lat.). 



