FAMILY TABANID.T: THE HORSE FLIES 151 



KEY TO GENERA* 



1. Himl tibiae with apical spurs, which may be quite small (Pangoniinae) 2 

 Hind tibite without apical spurs (Tabaninse) 15 



2. Eyes with distinct pile 3 



Eyes bare 9 



3. First posterior cell open 4 



First posterior cell closetl 5 



4. Face not produced, at most slightly convex (Osca Walker) (22). 



Scaptia Walker 

 Face much produced, snout-like Neopangonia Ad. Lutz 



5. Fourth posterior cell closed (15, 20) Scione Walker 



Fourth posterior cell open 6 



6. Third antennal segment furcate 7 



Third antennal segment not branched 8 



7. Third antennal segment branched. dorsally and ventrally (4). 



Pityocera Giglio-Tos 

 Third antennal segment branched only dorsally Elaphella Bezzi 



8. Cox« and femora slightly hairy Fidena Walker 



Coxae and femora densely covered with long pile (Erephopsis Rondani) 



(34, 35) Melpia Walker 



9. First posterior cell closed; face merely convex, not snout-like; ocelli 



present; palpi long, sabre-shaped (25, 29) Esenbeckia Rondani 



First posterior cell open 10 



10. Third antennal segment composed of at least seven annuli 11 



Third antennal segment composed of not more than five annuli; pro- 

 boscis short 13 



11. Posterior border of eye acutely angulate in female; proboscis very 



short; fork of third longitudinal vein without appendix; wings 



brownish in front, hyaline behind (1, 2, 3, 9) Goniops Aldrich 



Eyes of female not acutely angulate above; wings not so marked.... 12 



12. Proboscis but little longer than palpi; frons of female very wide below; 



fork of third longitudinal vein with appendix (5).. . . Apatolestes Williston 

 Proboscis much longer than palpi; frons of female narrow and almost 

 parallel-sided (31, 33) Buplex Austen 



13. Second antennal segment only half as long as the first (16, 26). 



Silvius Meigen 

 Second antennal segment much more than half as long as the first. ... 14 



14. Abdomen inflated, much wider than thorax; fork of third longitudinal 



vein with long appendix Neochrysops Walton 



Abdomen normal, depressed, not much wider than thorax; fork of third 

 longitudinal vein without appendix (10, 19) fChrysops Meigen 



* Checked by Dr. J. Bequaert. 



t Krober, li)26, Stett. Ent. Zeituns?, Ixxxvii, pp. 211-353, two plates; and, Neotropical. 

 1925, Konowia, iv, pp. 210-375, five plates. 



