fa:mily dolichupid.t: — the long-headed flies 219 



21. Third and fourth veins parallel apically 22 



Third and fourth veins strongly converging apically or the fourth 



strongly curved forward 23 



22. First antennal segment bare above (8, 33) * Peloropeodes Wheeler 



First antennal segment haired above at apex (55, 70). 



fGymnopternus Lcew 



23. Fourth vein with a rather sharply rounded curv^ature and parallel 



with the third at the tip (46) Paracleius Bigot 



Fourth vein straight beyond the crossvein or with a gentle curvature 

 (44, 61) 24 



24. Head conspicuously higher than wide, the face extending to the lower 



edge of the eyes; fourth vein curved beyond the posterior crossvein 



(29, 44 ) ' '. JTachytrechus Walker 



Head but little higher than wide, the face not reaching the lower edge 

 of the eyes; fourth vein straight beyond the crossvein (61, 76). 



Hercostomus Lcew 



25. Costa reaching to the fourth vein 26 



Costa ending at the third vein (58) §Asyndetus Lcew 



26. First antennal segment bare above 34 



First antennal segment haired above, at least apically 27 



27. Arista dorsal, rarely subapical 29 



Arista apical or practically so 28 



28. Third antennal segment bilobed or with a strong anuglar projection 



below on the basal third (30, 40) Hypocharassus Mik 



Third antennal segment triangular or subtriangular (18, 74). 



^Argyra Macquart 



29. Acrostical setae absent 31 



Acrostical setae present, two-rowed 30 



30. Fourth vein doubly bent at r.early right angles (68, 82). 



Syntomoneurum Becker 

 Fourth vein not sharply curved (3, 37) Stolidosoma Becker 



31. Arista long pubescent or plumose 32 



Arista very short pubescent or bare 33 



32. Third and fourth veins parallel or only a little convergent. 



Phylarchus Aldrich 

 Fourth vein strongly curved forward, very close to the third at its 

 apex; (Some species of Sarcionus and Pelastoneurus might come 

 here as a few have short genitalia). 



33. Palpi very small; face very narrow (1) Anepsiomyia Bezzi 



Palpi larger; lower section of face twice as wide as long (5, 34). 



Diostracus Loew 



34. Mesonotum with an elongate, longitudinal depression on the nosterior 



third or slightly less 35 



» Van Duzee, 1926, Tr. Amer. Ent. Soc. liii, i>p. 39-46 (Kophosoma). 



t Curran. 1933, Amer. Mus. Novit. No. 682, p. 2. 



t Green, 1922, Proc. U. S. N. M., Ix, Article 17. 



§ Van Duzee, 1919, Ent. News, xxx. p. 24S. 



H Van Duzee, 1925, Proc. U. S. N. M., Ixvi, .^rt. 23. 



