220 



NORTH AMERICAN DIPTERA 



Dolichopidffi II.— 16, Condylostylus sipho : 17. Sciapus unifasciatus; 18, Argyra; 19, 

 Plagioneurus univittatus: 20, Liancalus similis; 21. Rhaphphium ; 22. ^t,'X:Toly.7rirkoni 

 Diaphorus; 24, Dolichopus, d abdomen: 25. Pelastoneurus vagans ; 26. Hydrophorus, fiont 

 femur; 27, Scellus, front femur; 28, Scellus vigil. 



