DEXIIM, 355 



14. Facial ridges parallel; antennae inserted on line drawn through 



middle of eyes Tromodexia. 



Facial ridges divergent below; antennae inserted somewhat below 

 middle of eyes (Tachinidse, 112) . . . Stomatodexia. 



15. Eyes descending less than or hardly more than two-thirds the dis- 



tance to lateral oral margin. ...... 16 



Eyes descending nearly to lateral oral margin. ... 40 



16. Apical cell petiolate or closed in the margin. . . . 17 

 Apical cell open. . . . . . . . . . 21 



17. Posterior cross-vein nearer to bend of fourth vein than to the ante- 



rior cross-vein, or in the middle. ..... 18 



Posterior cross-vein nearer to anterior cross-vein than to bend. 20 



18. Fourth vein with stump at bend Megerlea. 



Fourth vein without stump. . . . . . . . 19 



19. Third antennal joint scarcely longer than second; cheeks without 



long, bristly hairs below. .... Megaparia. 



Third joint more than twice as long as second; cheeks with long 



bristly hairs below. ..... Melanodexia. 



20. Sides of face narrow, bare (22). . . . Melanophora. 

 Sides of face broad,' bristly. .... Microchsetina. 



21. Face distinctly carinate. ....... 22 



Face not carinate or but slightly so. ..... 28 



22. Antennae nearly as long as the face. . . . Camarona. 

 Antennae much shorter than the face. .... 23 



23. Abdomen wide and stout; short; oval, the first segment somewhat 



shortened. ........... 25 



Abdomen conical or elongate oval. ..... 24 



24. Sides of face bristly above. .... Gymnodexia. 

 Sides of face wholly bare (fig. 144). .... Dexia. 



25. Sides of face bare. ......... 26 



Sides of face hairy. ...... Trixodes. 



26. Abdomen with discal and marginal macrochaetae. . . 27 

 Abdomen without discal macrochaetae. . . Ateloglossa. 



27. Arista bare or pubescent. .... Megaprosopus. 

 Arista long plumose Phorostoma. 



28. Antennae inserted at or above the middle of the eyes. . 29 

 Antennae inserted below middle of eyes. .... 32 



