24 DirTERA OF NORTH AMERICA. 



moneura Big.), Stilpnogaster Loeic, Epitriptus Loew, Itamus 

 Loew, Tolmerus Loew, Cerdistus Loew, Proagonistes Loew, 

 Asilus Linn., Eccoptopus Loew, Rhadiurgus Loew, Pamponerus 

 Loew, Antiphrisson Loew, Echthistus Loew, Antipalus Loew, 

 Philodicus Loew, Lecania Macq., Atractia Macq., and Omma- 

 tius Wied. 



Most of the N. A. Asilidce, but by no means all, may be placed 

 in the genera hitherto established. I give, as far as I am able to 

 do so under such circumstances, the following list of genera known 

 to me as occurring on that continent: — 



I. Dasypogonina: 1. Dasypogon Meig., with several species 

 which will require the formation of some new genera; 2. Micro- 

 stylum Macq., 3. Discocephala Macq., 4. Plesiomma Macq., 5. 

 Stenopogon Loew, 6. Bathypogon Loew, t. Lastaurus Loew, 

 8. Euarmostus Walk., 9. Pheneus Walk., 10. Stichopogon L^oew, 

 11. Ceraturgtjs Walk., 12. Leptogaster Meig. The N. A. spe- 

 cies recorded as belonging to Dioctria Meig. are no Dioctrice at 

 all; at least Dioctr. octopunctata Say is by no means a true 

 Dioctria. 



II. Lap/trina: 13. Megapoda Macq., 14. Laphria Meig., 15. 

 Andrenosoma Bond., 16. Lampria Macq., IT. Atomosia Macq., 

 18. Laphystia Loew. 



III. Asilina: 19. Mallophora Macq., 20. Promachus Loew, 

 21. Erax Macq., 22. Proctacanthus Macq., 23. Mochtherus 

 Loew, 24. Epitriptus L,oew, 25. Ommatius Wied. 



Fam. XX. THEREUIDAE. 



Charact. — Three basal cells much prolonged; the two intercalary veins 

 present; third longitudinal vein furcate. Antennae with a terminal 

 style of variable form, sometimes wanting. No empodium. Under 

 lip fleshy. 



The principal genera belonging to this family are: Xestomyza 

 Wied., Baryphora Loew, Cionophora Egg., Exapata Macq., 

 Thereua Latr., Ectinorhynchtjs Macq., Anabarhynchus Macq., 

 Tabtjda Walk., Cyclotelus Walk., Phycus Walk., and Dimassus 

 Walk. 



The N. A. species with which I am acquainted may be conve- 

 niently placed under the genus Thereua Latr. In case the genus 



