250 



NORTH AMERICAN DIPTERA 



Syii)hida,' II. — 25, Ferdinandea ; 26, Volucella fasciata; 27, Eumyiolepta auricaudata; 28, 

 Syritta pipiens; 29, Xylota pigra; 30, Pipizella ; 31, Platycheirus erraticus; 32, Syrphus wiede- 

 manni; 33, Sericomyia militaiis ; 34, Polydontomyia curvipes ; 35, Scaeva pyrastri; 36, Tropidea 

 quadrata; 37, Baccha lemur; 38, Trichopsomyia; 39, Baccha ; 40, Apophysophora (S. Amer.) ; 

 41, Chrysotoxum. 



