24 DIPTERA OF NORTH AMERICA. 



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

 Loew, TOLMERUS Loew, CERDISTUS Loew, PROAGONISTES Loew, 

 ASILUS Linn., ECCOPTOPUS Loew, RHADIURGUS Loew, PAMPONERUS 

 Loew, ANTJPHRISSON Loew, ECHTHISTUS Loew, ANTIPALUS Loew, 

 PHILODICUS Loew, LECANIA Hacq., 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 s'ich circumstances, the following list of genera known 

 to me as occurring on that continent: 



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

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

 STYLUM Macq., 3. DiscocEPHALA Macq., 4. PLESIOMMA Maeq., 5. 

 STENOPOGON Loew, 6. BATHYPOGON Loeiv, 1. LASTAURUS Loew, 

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

 11. CERATURGUS Walk., 12. LEPTOGASTER Meig. The X. 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 Rond., 16. LAMPRIA Macq., 17. ATOMOSIA Macq. t 

 18. LAPHYSTTA Loew. 



lll.'Asilina: 19. MALLOPHORA Macq., 20. PfiOMACHUS Loew, 

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

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



FAM. XX. THEREUIDAE. 



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

 present ; third longitudinal vein furcate. Antennze with a terminal 

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

 lip fleshy. 



The principal genera belonging to this family are: XESTOMYZA 

 Wied., FARYPHORA Loew, CIONOPHORA Egg., EXAPATA Macq., 

 THEREUA Latr., ECTINORHYNCHUS 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 



