220 Wisconsin Academy of Sciences, Arts, and Letters. 
41. Face projecting below; slender species, the hypopygium often 
large .. Shapaerophoria (p. 238) 
Face receding; abdomen oval_ Xanthogeamma (p. 235) 
42. Thickly pilose species; the abdomen black, the basal part light 
yellow ... *iLeucozona 
Thinly pilose species, abdomen not so marked. 
43. Hind femora thickened... 
Hind femora slender. 
44. iSpecies wholly or chiefly reddish or lutescent. 
Black species, sometimes with luteous spots on face, humeri, 
and basal angles of abdomen. 
45. Scutellum unusually large, nearly square in outline; males 
dichoptic.*Chalcomyia 
Scutellum oval; males holoptic.*Myiolepta 
46. Face carinate; abdomen oval. Brachyopa (p. 239) 
Face tuberculate; abdomen more elongate.. *Hammerschmidtia 
47. Epistoma produced into a long porrect snout. Rhingia (p. 239) 
Epistoma not produced (compare Paragus sp. if small) ; facial 
orbits limited by a slender groove. Chilosia (p. 226) 
48. Third vein bent deeply into the first posterior cell. 
Third vein not bent deeply into the first posterior cell; third 
antennal joint elongate ... 
49. Arista very densely plumose, appearing as a solid mass, the 
arista itself also thickened.*Copestyium 
Arista feathery-plumose. 
50. Hairs of arista retrorse; males dichoptic.,Megametapon 
Hairs of arista not retrorse; males holoptic. Volucella (p. 239) 
51. Hind femora with a sharp tooth-like projection below neai dis¬ 
tal end; sixth vein beyond anal cell strongly curved’ 
large species.. ..Milesia (p. 248) 
Hind femora without such tooth. 
52. Frontal triangle of male strongly protuberant, rather large dark- 
colored species.. .Eristalis (p. 240) 
Frontal triangle not protuberant..... 
53. Epistoma produced into a long porrect snout..*Eicastrirhyncha 
Epistoma not produced. 
54. Thorax with distinct yellow markings; hind femora thickened; 
hypopygium enlarged . . . *Meromacrus 
Thorax not with distinct yellow markings, sometimes white- 
fasciate; femora sometimes thickened; hypopygium not 
conspicuously prominent. Eristalis (p. 240) 
55. Arista plumose. 
Arista bare or pubescent. 
56. Antennae elongate, the third joint more than twice as long as 
wide (Phalacromyia, Glaurotricha)- Volucella (p. 239) 
Antennae short, the third joint not more than twice as long 
as wide; third vein nearly straight, or gently or consider¬ 
ably curved into first posterior cell... 
