336 NORTH AMERICAN DIPTERA 



5. Costa with a very deep excision at the apex of the auxiliary vein; 



cruciate interf rontals developed 6 



Costa broken but the excision not extending into the cell; interf rontal 

 hairs present 10 



6. Mesopleura with strong bristles. 

 Mesopleura bare 



7. Proboscis very long, geniculate Paramilichia Malloch 



Proboscis geniculate, but not unusually long (19, 23). .Pholeomyia Bilimek 



8. Posterior margin of the eye excised at the middle 9 



Posterior margin of the eye not excised Milichia Meigen 



9. Four pairs of dorsocentrals (18, 22) Eccoptomma Becker 



One or two pairs of dorsocentrals (17, 22) Milichiella Giglio-Tos 



10. Apical cell very widely open, at most a little narrowed apically 11 



Apical cell only narrowly open (5, 12) Eusiphona Coquillett 



11. Bristles of the head and thorax strong; eyes at most short haired 12 



Bristles of head and thorax not strongly diiferentiated from the hair; 



eyes rather long pilose Arctobiella Coquillett 



12. Proboscis geniculate, long and chitinized; vibrissal angle usually dis- 



tinct 13 



Proboscis shorter and more or less fleshy, the labellse not elongate 

 though folding back; vibrissal angles not developed; face strongly 

 carinate (8) Hemeromyia Coquillett 



13. Posterior tibiae flattened and broadened 14 



Posterior tibiae not unusually flat and wide 10 



14. Pteropleura with one or more small bristles (Paramadiza Malloch; 



Mallochiella Melander) (1, 11) Hypaspistomyia Hendel 



Pteropleura without bristle 15 



15. Glossy black; frontal bristles weak (14, 15) Desmomyza, n. g. 



Dull colored; frontals stronger; two pairs of divergent frontals; inter- 



f rontals in differentiated rows (16, 10) Desmometopa Lcew 



16. Lower edge of the head horizontal and long (24, 25). 



Platophrymyia Williston 

 Lower edge of the head rounded or short 17 



17. Eyes hairy; palpi very large, projecting far beyond the oral margin 



(7) Phyllomyza Fallen 



Eyes bare or nearly so; palpi not projecting 18 



18. Five or six pairs of orbitals 19 



Three pairs of orbitals Cacoxenus Lcew 



19. Apical scutellars converging Neophyllomyza Melander 



Apical scutellars diverging Stomosis Melander 



