siTirmx-t. "21 



Marginal cell normally closed (rarely open, 

 Graptoinyza etc.) ; apical section of 4tii 

 vein distinctly recurrent ; antennae ex- 

 tremely plumose VoLUCKLLiN^;, p. 134. 



4. Third longitudinal vein distinctly looped 



downward into 1st posterior cell I'Ihistalix.i;, p. 154. 



Third vein not distinctly looped downward, 



but often slightly curved downward .... INIilesiinti-:, p. 226. 



5. Third vein without any downward loop or [p. 294. 



any appendix in 1st posterior cell CHUYSOTOXiNiE, 



Third vein with either a downward loop 



or an appendix in 1st posterior cell G. 



0. Arista dorsal ; antennne never seated on a 

 petiole ; 3rd vein not downward looped, but 

 with an appendix extending across middle 

 of 1st posterior cell ; 4th vein distinctly 



recurrent in apical section ; scutellum with [p. 807. 

 a blunt spine or tootli at each hind corner . 3Iicrodontin^, 

 An apical style ; anteiuui! generally seated 

 (m a conspicuous petiole ; 3rd vein with a 

 downward loop generally ending in a 

 sharp point with an appendix (as in 

 MiCRODONTiN.T3) but shorter; 4th vein 

 never recurrent at tip ; scutellum un- 

 armed ' Ckriina:, p. 321. 



Though authors are not unaiiiinoiis as to the number of sul)- 

 families to be recognized nor as to their exact lin)its, the above 

 series probably meets the views of the majority of present-day 

 writers, and it was the one adopted by Yerrall. The exact 

 affinities of several genera, iSericomijia and Myiolepta for instance, 

 still remain uncertain. 



Subfamily SYRPHIN/E. 



Head: antennae moderately long, usually more or less pendant, 

 if elongate and more or less porrect then not ])laced on a pro- 

 duced frous or prominence; arista bare or at most moderately 

 pubescent, never plumose ; face excavated or nut below antenna?, 

 with or without central bump, generally produced, often con- 

 spicuously so, over ui)per border of moiitli ; pubescence very 

 variable in quantity. Eyes varying from bare to densely pubes- 

 cent, generally contiguous in S for a greater or less distance. 

 Thorax and ahdoiuen of normal relations to head, or the laltrr 

 extremely attenuated, sometimes rounded. L^-vs generally simple, 

 sometimes (Plati/clilnis) wit'j conspicuous specilic characters ; 

 femora seldom spinose or dentate. Win</s with very uniform 

 venation; marginal cell always distinctly open, JJrd vein seldom 

 looped downward into 1st posterior cell ; anterior cross- vein 

 almost always distinctly before middle of discal cell; tip of 4tli 

 vein not recurnMit (except in Oi-thonenva). 



This subfamily is rather a heterogeneous one, but it is difficult 

 satisfactorily to subdivide it without making a number of groups 

 and leavinti: over certain intermediate or abnormal g>Miera. 



