90 



NORTH AMERICAN DIPTERA. 



70. Antennae inserted low down, near the middle of the head in profile ; 



face not longer than the front. Temnostoma St. Farg. and Serv. 



Antenna situated high up, on a conical process ; front short, face much 



produced downward; antennae long or short. Sphecomyia Latreille. 



xVUXILIARY TABLE. 

 1. Marginal cell closed : 



Copestylum, 4, 5, 8. 

 Milesia, 2, 7. 

 Meromacrus, 2. 

 Lycastrirhyncha, 2, 6. 



Megametapon, 4, 5, 8, 10. 

 Priomerus, 2, 8. 

 Eristalis, 2, 5, 8. 

 Volucella, 4, 5, 8. 



2. Tiiird vein bent deeply into the first posterior cell : 



Didea, 8. Salpingogaster, 9. 



Milesia, 1, 7. Priomerus, 1, 5, 8. 



Meromacrus, 1. Eristalis, 1, 5, 8. 



Lycastrirhyncha, 1, (5. Tropidia, 7. 



Ceriogaster, 1, 9. I'terallastes. 



Helophilus, 10. Asemosyrphus, 10. 



Mallota, 8, 10. Teuchocncmis. 



Polydontomyia, 7. Senogaster, 7, 9. 

 Platynochaetus, 4. 



3. First posterior cell with a stump of a vein from the third longitudinal 



Omegasyrphus, 4, 8. 

 Microdon, 4, 8. 



Mixogaster, 4, 9. 



Rhopalosyrphus, 4, 9. 



Ubristes, 10. 

 4. Antennae elongate: 



Sphyximorpha, 9. Chrysotoxum, 8. 



Pipiza, 8. Mixogaster, 3, 9. 



Omegasyrphus, 3, 8. Rhopalosyrphus, 3, ' 



Microdon, 3, 8. Lepidostola. 



Ubristes, 3, 10. Chrysogaster, pt. 



Paragus, pt. 8. Volucella, 1, 5, 8. 



Megametapon, 5, 10. Spilomyia, pt. 7. 



PIatynocha?tus. 2. Copestyluni, 1, 5, 8. 



Sphecomyia, pt. Phalacromyia, 5. 

 o. Arista plumose : 



Chilosia, pt. 8. Brachyopa pt. 



Eristalis, pt. 1, 2, 8. Sericomyia. 



Arctopliiia. Voluccllii, 1,4,8. 



Megametapon, 4, 10. Plialacromyia, 4. 



Copestyluni, 1, 4, 8. 

 0. Epistoma ])roduced into a long j)orri'cted snout: 



Rliinuia. Lvcastrirhvnchn, 1, 



