274 C. H. TYLER TOWNSEND. 



4. Sides of face bare 5. 



Sides of face clothed with short bristles Prorhyncliops* B. B 



5. Palpi very short, thickened at tip, niacrochpette only marginal. 



Proseiia St. F. and Serv. 



Palpi moderately long, not at all or but little thickened at tip; macrochsetse 



usually discal and marginal 6. 



6. Claws of % extraordinarily long IVIooliloi^oins* B. <t B. 



Claws of both sexes short Ulyioiiiiina B. & B. 



7. Abdomen densely covered with spinose raacrochfeta- 8. 



Abdomen with regularly arranged macrochEetfe 9. 



8. Vibrissfe inserted some distance above oral margin. 



Hyi^trichodexia v. Eod. 

 Vibrissse inserted on oral margin Batliydexia v. d. W. 



9. Eyes descending not more than two-thirds distance to the lateral oral mar- 



gin 10. 



Eyes descending at least three-fourths of the distance to the lateral oral 

 margin 12. 



10. Fourth vein with a stump at its bend Scotiptera Mcq. 



Fourth vein without stump at bend 11. 



11. Macrochsetfe of abdomen discal and marginal Rliyiicliotlexia Big. 



MacrochfEtffi of abdomen only marginal , Myocera E. D. 



12. Facial ridges parallel : antennge inserted on a line drawn through middle of 



eyes Troniodesia Rdi. 



Facial ridges divergent toward oral margin; antennae inserted somewhat 

 above a line drawn through middle of eyes...Stoinatodexia B. & B. 



13. Eyes descending less, or hardly more than two-thirds distance to the lateral 



oral margin 14. 



Eyes descending nearly or quite to oral margin, the cheeks consequently very 

 narrow dorse- vent rally (Thelai rinse) 33. 



14. Apical cell petiolate, or closed in margin (Melanophorinse) 15. 



Apical cell open (Dexiinse) 18. 



15. Hind cross vein nearer to bend of fourth vein than to the small cross-vein, 



or in the middle between the two; cheeks beset with short bristly hairs. .16. 

 Hind cross-vein nearer to small cross-vein than to bend of fourth vein. ...17. 



16. Fourth vein with a stump at bend Megerlea E. D. 



Fourth vein without stump at bend, cheeks as wide as diameter of eyes. 



iUegaparia v. d. W. 



17. Sides of face narrow, naked Melaiiophora Meig. 



Sides of face broad, clothed with bristles MicrochsPtiiia v. d. W. 



18. Face distinctly carinate 19. 



Face not carinate, or only faintly so 22. 



19. Antenufe nearly as long as the face Cainaroiia v. d. W. 



Antennge much shorter than the face 20. 



20. Abdomen wide and stout, short oval, first segment somewhat shortened. ..21. 

 Abdomen conical or elongate oval Dexia Meig. 



21. Sides of face naked I'liorostoiiia E. D. 



Sides of face hairy IVIorpliouiyia Edi. 



* Nothing is said of the character of the proboscis in the description of this 

 genus, but from its close relationship with Hystrisiphona, as indicated by Br, and 

 V. Bgst., I infer that it belongs to this group. 



