I2 8 NORTH AMERICAN DIPTKRA. 



EE. Em podia trifid.* 



9. Antennae composed of twelve joints in both sexes. 



Arnoldia K. 



10. Joints of antennae more numerous in male than in fe- 



male; last abdominal segment not swollen. 



Dryomyia K. 



11. Antennae composed of more than twelve joints; last ab- 



dominal segment swollen ( 9 ) Dasyneura. 

 BB. Anterior border of the wings without squamae; claws simple. 

 F. Empodia simple. 



12. Palpi with four joints; antennae fourteen-jointed, verti- 



cillate. ...... Schizomyza K. 



13. Palpi four-jointed; antennae fourteen-jointed, not verti- 



cillate Polystepha. 



14. Palpi three-jointed; costa with squamae. Cystiphora K. 



15. Antennas fonrteen-jointed, not verticillate; palpi with 



less than four joints. . . . Asphondylia. 

 FF. Empodia trifid; antennae verticillate. 



16. Palpi with one or two joints. . Rhopalomyia R. 



17. Palpi with three joints. . . Oligotrophus L,at. 



18. Palpi with fcnir joints, long. . . . Janetiella K. 



19. The second vein reaches the tip of the wing, palpi with 



four joints. ..... Mayetiola K. 



20. Palpi with four long joints. . . . Mikiola K. 



21. Thorax produced over head. . . Hormomyia. 

 BBB. Thorax not prolonged over the head; antennae fourteen-jointed 



in both sexes; in the male each joint of the flagellum with two 

 bead-like swellings, giving an appearance of twenty-six joints 

 for the antennae. 



G. Claws of front tarsi bifid, or curved at right angle and enlarged 

 at extremity; or the empodium trifid. 



22. Empodia trifid Putoniella K. 



23. Verticils of antennae curved and irregular; larvae zo- 



ophagous Bremia Rond. 



24. Verticils regular; all the claws bifid. Dicrodiplosis K. 



25. Verticils regular; hind claws not bifid; larvae mycophag- 



ous Mycodiplosis R. 



26. Claws simple, bent at right angles and dilated below 



near extremity. . . . Octodiplosis ( >iard. 

 GG. Claws simple, bent or curved at right angles, but not en- 

 larged; em podia simple. 



27. Three-jointed palpi; scales of wings elongated and nar- 



rowed at base Endaphis K. 



28. Second longitudinal vein terminates before the tip of the 



wing; larvae zoophagous. . Arthrocnodax Rbs. 



29. Palpi with a single joint. . Monarthropalpus R. 



30. Palpi two-jointed, the first long and attenuated in the 



middle Massalongla K. 



31. Palpi with three joints; second joint of antennae with a 



tooth Acrodiplosis K. 



* I use this expression, not being certain whether or not the trifid 

 character is due to real pulvilli. Kieffer simply begs the question by 

 the expression 'pelote unique,' 'pelotes trois'. 



