8. Front tibiae without terminal spurs. ..... 10 



Front tibiae with a single terminal spur; hind tibiae with two. 9 

 Front tibiae with two terminal spurs; hind tibiae with two. 



Triptotricha. 



9. Antennal style slender and jointed; fourth posterior cell closed (5) . 



Pheneus. 



Terminal arista not jointed; fourth posterior cell sometimes want- 

 ing (14, 15). ... . Dialysis. 



10. Discal cell wanting; four posterior cells only (1, 2). 



Hilarimorpha. 

 Discal cell present; five posterior cells. n 



n. Third joint of the antennae round, oval or pointed. . . 13 

 Third joint of the antennae kidney-shaped, with a dorsal or sub- 

 dorsal arista. . . . . . . . . . 12 



12. Hind tibiae with a single spur; anal cell open; first antennal joint 



elongate and thickened (8). . . . Symphoromyia. 



Hind tibiae with two spurs; anal cell closed; first antennal joint 



not elongate and thickened (9,21). . . . Atherix. 





13. Hind tibiae with two spurs; anal cell open (fig. 51). Leptis. 

 Hind tibiae with a single spur; anal cell closed. ... 14 



14. Third antennal joint onion-shaped or conical, with a slender, arcu- 



ate, terminal bristle (6, 7) Chrysopila. 



Third antennal joint elongate; not with a slender terminal 

 bristle. .......... 15 



15. Third antennal joint with a short terminal style (1O) . Ptiolina. 

 Third antennal joint emarginate above, pointed, without style (11) . 



Spania. 



Bolbomyia. 'More or less related to Rupellia, and may be placed 

 among the Xylophagidae, its somewhat aberrant venation notwith- 

 standing. Characteristic is the shape of the antennae; the third joint 

 consists of four or five divisions, the first of which is much larger and 

 swollen'. L,oew. B. nana, District of Columbia. Length about three 

 millimeters. This species has not been recognized since its descrip- 

 tion, nor the genus. Possibly it belongs to the There vidae. 



