FAMILY MYCETOPHILID.E THE FUNGUS GNATS 127 



44. Mesopleural and hypopleural bristles absent; hind coxa with a fairly 



strong bristle at base 45 



Mesopleural bristles present; hind coxa usually without basal bristle. . . 49 



45. Costa produced beyond tip of third vein (42) Anatella Winnertz 



Costa ends at tip of third vein 46 



46. Fifth vein forks beyond fork of fourth (43) Exechia Winnertz 



Fifth vein forks below or before fork of fourth 47 



47. Second anal vein strong and distinct (44) Rhymosia Winnertz 



Second anal vein weak or absent 48 



48. First anal vein very long and distinct, attaining the middle of the fork 



of the fifth vein (45) Brachypeza Winnertz 



Fii-st anal vein shorter and less distinct (46) Allodia Winnertz 



49. Pteropleural bristles present; tibial bristles long and strong 53 



Pteropleural bristles absent 50 



50. Tibial bristles long and strong; auxiliary vein ends in first vein 



(=: Johannsenia) (17) Dynatosoma Winnertz 



Tibial bristles small, at most a little longer than the diameter of the 

 tibia 51 



51. Second palpal segment greatly thickened (48) Cordyla Meigen 



Second palpal segment normal 52 



52. Fifth vein forks beyond fork of fourth; auxiliary vein ends free 



(including Telmaphilus) (49) Phronia Winnertz 



Fifth vein forks below or before fork of fourth; auxiliary vein ends 

 normally in the first (50) Trichonta Winnertz 



53. Fifth vein forked 54 



Fifth vein simple 56 



54. Anterior branch of fifth vein slightly divergent apically from second 



branch of fourth but parallel with or convergent towards .second 

 branch of fifth; hypopleura and pteropleura generally quite large 

 (including Mycothera ami Opistholoba) (15, 51) . . . .Mycetophila Meigen 

 Anterior branch of fifth parallel with second branch of fourth but 

 slightly divergent from second branch of fifth 55 



55. Pronotal lobes with long bristles; fifth vein forks scarcely if any before 



the anterior crossvein (82) Epicypta Winnertz 



Pronotal lobes without long bristles; fifth vein forks well before the 

 anterior crossvein Delopsis Skuse 



56. Second branch of fourth and first branch of fifth vein slightly di- 



vergent; hypopleura and pteropleura large; middle tibia with ventral 



bristles (53) Zygomyia Winnertz 



Second branch of fourth and first branch of fifth vein parallel; hypo- 

 pleura and pteropleura small; middle tibia without ventral bristles 

 ( 54 ) Sceptonia Winnertz 



