Dolichopodidae. (55 



22. Middle tibiæ nearly twice as long as the tarsi, not 

 brown above; hind tibiæ entirely and base of hind 



tarsi yellow 20. Wahlbergi. 



23. Second and third joint of middle tarsi plumed, the 

 last two joints silvery; hind femora with one pre- 



apical bristle 21. jjeimahts. 



— Second joint of middle tarsi normal; hind femora 



with more than one preapical bristle 24. 



24. Third and fourth joint of middle tarsi plumed, fifth 



joint silvery ; hind tibiæ yellow 22. popularis. 



— The joints of the middle tarsi normal, only the last 

 joint silvery on the anterior side ; hind tibiæ almost 



quite black 23. urhanus. 



25. Wings with a snow-white spot at the apex 24. apicalis. 



— Wings without a white spot at the apex 26. 



26. Basal joint of middle tarsi with one bristle above; 



hind femora fringed beneath 27. 



— Basal joint of middle tarsi without any bristle above. . . 30. 



27. Wings with a costal swelling; front tarsi with the 



three middle joints bearded with short, erect hairs. . . 28. 



— Wings without costal swelling ; front tarsi not bearded 28. arhustorum. 



28. Front tarsi with the three middle joints straight, and 

 with a bristle only at the apex of the first, or of 



the first and second joint 29. 



— Front tarsi with the three middle joints curved, 

 and with a curved bristle at the apex of the three 



first joints 27. ciliefemoratus. 



29. Front tarsi with a bristle only at the apex of the 

 first joint; antennæ black ish, basal joint yellow 



beneath, third joint longer than broad 25. trivialis. 



— Front tarsi with a bristle at the apex of first and 

 second joint; antennæ yellowish, third joint brownish 



at the apex, not longer than broad 26. festivus. 



30. Discai vein bent rectangularly, often with a small 

 veinlet ; front tibiæ with a long thin hair at tip 31. 



— Discai vein bent obtusely 32. 



31. Hind metatarsus only black at tip, with two bristles 



above; hind femora not fringed 29. nitidus. 



— Hind metatarsus quite black, with only one bristle 



above ; hind femora black fringed beneath 30. griseipennis. 



32. Antennæ long, third joint more than twice as long 

 as broad, with a long, pointed apex turned up at 



the tip 33. 



— Antennæ not specially long, the third joint not twice 



as long as broad, much less pointed 34. 



33. Antennæ black, basal joint yellow beneath; front 



tibiæ without any long, thin hair at the tip 31. acuticornis. 



— Antennæ yellow, blackish above and at apex; front 



tibiæ with a long, thin hair at the tip 32. longicornis. 



34. Epistoma distinctly pubescent ; posterior ventral lobes 



5 



