24 DIPTERA OF NORTH AMERICA. 



moneura Big.), STILPNOGASTER Loew, EPITRIPTUS Loew, ITAMUS 

 Loew, TOLMERUS Loew, CERDISTUS Loew, PROAGONISTES Loew, 

 ASILUS Linn., ECCOPTOPUS Loew, RHADIURGUS Loew, PAMPONERUS 

 Loew, ANTIPHRISSON Loew, ECHTHISTTJS 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. BATHYPOQON Loew, 7. LASTAURUS Loew, 

 8. EUARMOSTUS Walk., 9. PHENEUS Walk., 10. STICHOPOGON Loew, 

 11. CERATURGTJS Walk., 12. LEPTOGASTER Meig. The K 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. Laphrina: 13. MEGAPODA Macq., 14. LAPHRIA Meig., 15. 

 ANDRENOSOMA Bond., 16. LAMPRIA Macq., 17. ATOMOSIA Macq., 

 18. LAPHYSTTA Loew. 



III. Asilina: 19. MALLOPHORA Macq., 20. PROMACHUS Loew, 

 21. ERAX Macq., 22. PROCTACANTHUS Macq., 23. MOCHTHERUS 

 Loew, 24. EPITRIPTUS Loew, 25. OMMATIUS Wied. 



FAM. XX. THEREUIDAE. 



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

 present ; third longitudinal vein furcate. Antenna 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., 

 TABUDA 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 



