268 



NORTH AMERICAN DIPTERA. 



The occurrence of Megamerina Rondani in America 

 lacks confirmation. It has the auxiliary very distinct 

 and probably belongs more properly with the Sepsidse. 



TABLE OF GENERA. 



1. Antennae much elongated, the third joint slender (1, 2). 



Loxocera. 

 Antennae shorter than the face, the third joint oval or rounded. 2 



2. Face nearly perpendicular in profile; anal cell noticeably shorter 



than the second basal cell (3,4). . . . Chyliza. 



Face retreating in profile; anal cell as long or longer than the sec- 

 ond basal cell. . .... Psila. 



Fig. 105. Sepsidae. i, Sepsis, wing; 2, Sepsis, head; 3, Sepsis, 

 front leg; 4, Prochyliza, head; 5, Piophila, wing; 6, Piophila, head; 

 7 Michogaster, head (S. A.); 8, iMichogaster, wing. 



