300 THE XOETR AMERICAN UMPIDJE—COQUILLETT. vol.xviii. 



16. Auul cell preseut, sixtli vein uever wholly wanting 17 



Anal cell wholly wanting, only the vein at its apex sometimes present, 



sixth vein wholly Avauting, discal cell united with one of the other 

 cells 31 



17. Discfil cell present, complete 18 



Discal cell united with one of the other cells 30 



18. Three veins issue from the discal cell, fourth vein always simple, never 



forked 19 



Two Aeins issue from the discal cell 23 



19. Vein at apex of anal cell nearly parallel with the hind margin of the wing, 



anal cell much shorter than the second hasal 20 



Vein at apex of anal cell not parallel with the hind margin of the wing, anal 



cell almost as long as or longer than the second hasal cell 22 



20. Prohoscis as long as or longer than height of head, antenuic distinctly three 



jointed 21 



Prohoscis shorter than height of head, antenna- a])pareutly two jointed 



Microphorus (p. 409). 



21. Face naked Bhamphornyia (p. 409). 



Face clothed with l)ristly hairs Neocota fp. 434). 



22. Second vein termiiuites in the costa, anal cell closed far from the wing 



margin Sciodrom /« . 



Second vein terminates in the first, anal cell reaches the wing margiu 



Ifythicomyia (p. 409). 



23. Fourth vein simple, not forked 24 



Fourth vein forked, anal cell as long as or longer than the second basal, 



the vein at its apex nearly perjiendicular to the hind margin of the 

 wing Meyhyperus (p. 435). 



24. Vein at apex of anal cell nearly i)erpendicular to the hind margin of the 



wing 25 



Vein at apex of anal cell nearly parallel with the hind margin of the wing- 

 Some females of Bhamphomyia (p. 409). 



25. Antennal arista apical 26 



Antennal arista subdorsal, third antennal joint oval, anal cell shorter than 



the second basal Ocydromia. 



26. Anal cell as long as or longer than the second basal 27 



Anal cell shorter than the second basal, origin of second vein from the 



first nearer to tlie humeral than to the small cross vein. Leptope:a (p. 435). 



27. Origin of the second veiu nearer the small cross vein than to tlie humeral, 



or midway between tlieui 28 



Origin of the second vein nearer the humeral than to the suiall cross \eiu 



Syueches (p. 436). 



28. Vein between first and second basal cells present 29 



Vein between first and second basal cells wanting Syndyas. 



29. Eyes in both sexes widely separated oi] the face, under side of first two 



joints of hind tarsi bearing short black spines Hyhos (p. 437). 



Eyes in both sexes contiguous ou the face, under side of hind tarsi destitute 



of stout black spines Euhybiis ( ii. 437). 



30. Middle femora sleuder, vein at apex of anal cell uearly parallel with the 



hind margin of the wiug Cyrloma. 



Middle femora greatly thickened, vein at apex of anal cell nearly perpen- 

 dicular to the hind margin of the wing PUttypalpus (p. 438). 



31. Antennal arista apical 32 



Antennal arista dorsal or subdorsal 33 



32. Frout femora thickened Tachydromia (p. 439). • 



Front femora not thickened Brapel'i^. 



33. Palpi broad, front of an etjual breadth St)Ji>on. 



Palpi narrow, elongate - Phoueittisca. 



