326 



NORTH AMERICAN DIPTRRA. 



Fig. 132. Helornyzidae. i, Leria, sp. wing; 3, Anorostoma, head; 

 5, Scoliocentra helvola, middle tibia and tarsus. 



5. Eyes very small; four dorsocentral bristles; arista very long. 6 

 Eyes not very small. ...... .7 



6. All the tibiae without bristles on outer side; hind femora of male 



often emarginate at base below. . Eccoptomera L,oew. 



Middle tibiae at least with bristles on outer side. . Oecothea. 



7. Four pairs of dorsocentral bristles. ...... 



But three pairs of dorsocentral bristles; third antennal joint short; 

 bristles of costa small Tephrochlamys. 



8. Costal border of wings noticeably bristly (fig. 130). . Leria. 

 Costal border with very small bristles. . . Heteromyza. 



