186 



NORTH AMERICAN DIPTERA 



Therevidse I. — 1, Tabuda ; 2, Psilocephala ; 3, Psilocephala, antenna; 4, Chromolepida 

 bella, antenna; 5, Chrmoinolepida bella, head from above: 6, Metaphragma planiceps; 7, Tabuda 

 fulvipes; 8, Thereva melaneura; 9, Epomyia sumichrasti. 



