90 NORTH AMERICAN DIPTERA. 



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



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



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



produced downward ; antennae long or short. SPHECOMYIA Latreille. 



AUXILIARY TABLE. 



1. Marginal cell closed : 



Copestylum, 4, 6, 8. Megametapon, 4, 5, 8, 10. 



Milesia, 2, 7. Priomerus, 2, 8. 



Meromacrus, 2. Eristalis, 2, 5, 8. 



Lyeastrirhyncha, 2, 6. Volucella, 4, 5, 8. 



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



Didea, 8. Salpingogaster, 9. 



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



Meromacrus, 1. Eristalis, 1, 6. 8. 



Lycastrirhyncha, 1, 6. Tropidia, 7. 



Ceriogaster, 1,9. Pterallastes. 



Helophilus, 10. Asemosyrphus, 10. 



Mallota, 8, 10. Teuchocnemis. 



Polydontomyia, 7. Senogaster, 7, 9. 

 Platynochaetus, 4. 



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



Mixogaster, 4, 9. Omegasyrphus, 4, 8. 



Rhopalosyrphus, 4, 9. Microdon, 4, 8. 



Ubristes, 10. 



4. Antennae elongate: 



Sphyximorpha, 9. Chrysotoxum, 8. 



Pipiza, 8. Mixogaster, 8, 9. 



Omegasyrphus, 8, 8. Rhopalosyrphus, 3, 9. 



Microdon, 3, 8. Lepidostola. 



Ubristes, 3, 10. Chrysogaster, pt. 



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



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



Platynochaetus, 2. Copestylum, 1, 5, 8. 



Sphecomyia, pt. Phalacromyia, 5. 



5. Arista plumose : 



Chilosia, pt. 8. Brachyopa pt. 



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



Arctophila. Volucella, 1, 4, 8. 



Megametapon, 4, 10. Phalacromyia, 4. 

 Copestylum, 1, 4, 8. 

 C. Epistoma produced into a long porrected snout : 



Rhingia. Lycastrirhyncha, 1, 2. 



