Syrphidae. 41 



the spots are more or less glaucous and the basal 



spots large 22. 



20. Frons inflated, especially in the male; abdominal 



spots strongly lunulate ; eyes hairy 18. Lasiophthicus. 2,'f 



— Frons not inflated ; abdominal spots sometimes lunulate 



but oftenest of other shape; eyes bare or hairy 21. 



21. Cubital vein looped; abdomen somewhat flat and 



marginate; scutelium without marginal fringe below 17. Bidea.^'^O 



— Cubital vein not looped (except somewhat in S. 

 annulipes and lapponicus) ; scutelium with a fringe 



below the margin 19. Syrphus. 'J-\o:> 



22. Body densely and long pilose, abdomen short ovate, 



broader than thorax, black with only the apex reddish 15. Eriozona. Wj^ 



— Body not densely and long pilose, abdomen not 



short ovate, whitish or glaucous at the base 23. 



23. Abdomen with only one basal band; wings with a 

 dark spot on the middle; epistoma somewhat de- 



scending, with a dark middle stripe 14. Leucozona. AiO 



— Abdomen with three pairs of spots; wings without 

 spot; epistoma not descending, without black middle 



stripe 16. Ischyrosyrphus. XJ^L 



24. Alula almost wanting; abdomen very long and nar- 

 row 23. Baccha. yKa »^- 



— Alula of ordinary size ; abdomen less long and nar- 

 row, only constricted about the base 22. Doros. ^jO 



25. Alula almost wanting; abdomen clavate, constricted ' 

 about the base, black, generally with yellow mark- 



ings ; hind femora thickened and spinose beneath .... 26. 



— Alula of ordinary size; abdomen not clavate, red- 

 dish or brown; hind femora not thickened or spinose. . . 27. 



26. Wings with the lower outer angle of first posterior 

 cell rounded and the lower marginal cross-vein 

 oblique ; arista slightly pubescent ; abdomen with 



no process at the base 24. Sphegina. J>C c 



— Wings with the lower outer angle of first posterior 

 cell almost rectangular, and both marginal cross- 



veins perpendicular; arista bare; on each side of 'X- - 



the base of abdomen a pointed process 25. Neoascia. -^ I *^ 



27. Epistoma not bec-like produced 26. Brachyopa.'i^i ^ 



— Epistoma bec-like produced 27. Rhingia. j> ^. 



II. Volucellinae. 



Antennæ somewhat elongated, drooping, arista long-plumose. 

 Epistoma hollowed below the antennæ, with a central knob in the 

 middle and below it somewhat retreating; it is rather produced and 

 descending, hairy and of whitish or yellow colour. Eyes touching in 

 the male. Subcostal cell closed ; medial cross-vein before the middle 



