AMERICAN DIPTERA. 203 



HYBOTIN^. 



18. Third vein simple 19. 



Third vein forked 07. 



19. Anal cell shorter than the second basal 24. 



Anal cell as long as the second basal or longer 20. 



20. Fourth vein forked ; hind femora not incrassate • . . .illegliy penis Loew. 

 Fourth vein simple; hind femora more or less thickened 21. 



21. Origin of the second vein nearer to the humeral than to the anterior cross-vein. 



Syueches Walker. 

 Origin of the second vein not nearer the humeral 22. 



22. Vein between the first and second basals indistinct Syii(iya$« Loew. 



Vein between the first and second basals distinct 23. 



23. Stout, bronzed species with enormously thickened hind femora (Brazilian). 



liaetistomyia gen. nov. 

 More slender species of black or blue-black coloration Hy bos Meigen. 



24. Three veins at the apex of the discal cell 25. 



Two veins at the apex of the discal cell 26. 



25. Hind legs lengthened ; tibiae straight Eiitliy iieiira Macquart. 



Hind femora thickened ; hind tibiie bowed Oedalea Meigen. 



26. Third autenual joint conical, with a terminal bristle lieptopeza Macquart. 

 Third autenual joint oval ; bristle subdorsal Ocydroinia Meigen. 



27. Anterior branch of the third vein terminating in the second vein. 



RIepharoprocIa Loew. 

 Anterior vein terminating in the costa Bracliystonia Meigen. 



MYTHICOMYIIN^. 



28. No discal cell ; second vein ending in the costa. . Hilaroniorpha Schiner. 

 Discal cell present; second vein ending in the first. 



Mythicoiuyia Coquillett. 



EMPIDIN^. 



29. Discal cell wanting C'y rtoma Meigen. 



Discal cell present 30. 



30. Third vein simple 31. 



Third vein furcate 34. 



31. Proboscis not longer than the head, generally extending straight forward . . 32. 

 Proboscis longer than the head ; generally directed backwards ; anteunge 



plainl.v three-jointed 33. 



32. Eyes of the male separated ; hypopygium minute. 



Mierophorus Macquart. 



Eyes of the male contiguous ; hypopygium large, pedunculate, and flexed to 



the right Holoclera Schiner. 



33. Face naked Rliainpliouiyia Meigen. 



Face provided with bristly hairs 9f eocota Coquillett. 



34. Proboscis evidently longer than the head 35. 



Proboscis not longer than the head 39. 



TKANS. AM. ENT. SOC, XXVIII. JULY, 1902 



