NORTH AMERICAN DIPTP:RA. 135 



14. Tliird auteniial Joint shorter than tlie strongly elongated second 15. 



Third antenna! joint as long as, or longer than the second 16. 



15. Palpi distinct, moderately long Ecliiiioniyiji, Duni. 



Palpi very indistinct, rudimentary C'liphocera Mcq. 



16. Arista 3-jointed, geniculate;* head swollen 17. 



Arista 2-jointed, or if 3-jointed then never geniculate 18. 



17. Second aristal joint as long as, or longer than last; both sexes with orbital 



bristles Goilia. 



Second aristal joint considerably or decidedly shorter than last; male with- 

 out orbital bristles, species with facies of C'H«yj/Kj/(a....l*!>ieudo};<mia. 



18. Hind tibiie ciliate ou the outside Argyropliylax B. i^ IJ. 



Hind tibiaj not ciliate 19. 



19. Hind cross-vein very oblique, arising opposite or before small cross-vein, and 



ending half way between latter and bend of fourth vein, or nearer to 



small cross-vein . 20. 



Hind cross-vein normal, always arising below small cross-vein 22. 



20. Proboscis long, sleuder, labella scarcely at all developed. 



Kiplioplagia Twns. 

 Proboscis short, stout, labella well developed 21. 



21. Arista geniculate Ciuiiioclitefa Twns. 



Arista not geniculate I'lagia Mg. 



22. Third autennal joint as long, or at most twice as long as second 23. 



Third joint more than twice as long as secondt 37. 



23. Next to last joint of arista strongly elongate 24. 



Next to last joint hardly longer than wide .25. 



24. Head, and especially front, swollen C'lii'plialia Kdi. 



Head not i)articularly swollen Neiiioolia'ta v. d. \V. 



25. Antenna? nearly or not quite so long as face, second joint elongate 26. 



Antennse much shorter than face, second joint not elongate 29. 



26. Palpi rudimentary or absent 28. 



Palpi well developed 27. 



27. Vibrissse inserted well above oral margin ; robust, very hairy species. 



Tat'liiiioiiijia Twns. 

 Vibris.S£e inserted nearly on oral margin ; smaller, not hairy sjiecies. 



Tacliiiia Mg. s. Sch. 



28. Cheeks with one or more bristles in front of base of eye. 



Trioliopliora Mvq. 

 Cheeks without such bristles ia.Viiiiioiiiiiia v d. W. 



29. Head broad, more or less swollen ; frontal bristles all or partly weak 30. 



Head not swollen, with rather strong frontal bristles 33. 



.'{0. Frontal bristles alike, weak and short, arista not distinctly jointed ; abdomen 



and wings rather short 31. 



Frontal bristles mostly long and stout, but with some very short and weak 

 ones among them ; arista distinctly 3-jointed ; abdomen and wings lon- 

 ger, larger species i"IIe;;apro>*«pii«» M((|. 



31. Abdomen short conical .Millofjraiiiuia Mg. 



Abdomen longer, ovo-conical or oval 32. 



* Trixa, witli the arista bent, not geniculate, does not belong here. 



t Masicerii has the third antennal joint sometimes only twice as long as .second. 



TRANS. AM. ENT. .SOC. XIX. JUNE, 1S92. 



