3 I2 



NORTH AMERICAN DIPTKRA. 



10 



Fig. 123. Oscinidse. 8, Siphonella, n. sp. venation; 9, Siphonel/a, 

 head; 10, Ectecephala (?) species (Brazil), head; u, Ectecephala, wing; 

 12, Eurina, sp. antenna. 



TABLE OF GENERA. 



1. The costal vein reaches to the tip of the third longitudinal vein 



or a little beyond. ... 10 



The costal vein reaches to the tip of the fourth longitudinal vein. 2 



2. Second longitudinal vein very short, terminating in the costa near 



or but little beyond the insertion of the first vein. . . 3 



The second section of the costa is at least as long as the third sec- 



tion. 



Asteia. 

 Sigaloessa. 



3. Posterior cross-vein absent. .... 

 Posterior cross-vein present (7). . 



4. Antennal bristle thickened, style-like. .... 5 

 Antennal arista as usual, slender, bare, pubescent or rarely plu- 

 mose. ........... 6 



5. Hind tibiae with a curved spur at the tip on inner side. 



Ceratobarys. 

 Hind tibiae without such spur (2). . . Elachiptera. 



6. Hind tibiae with a curved spur at tip on inner side; proboscis often 



elongated and geniculate (1) Hippelates. 



Hind tibiae without such spur. ....... 7 



