292 DUEHAM DIPTERA. 



XXXIV. 



21 (22). Antennae as long as the face ; third joint with a sharp 



upper corner; arista kneed in both sexes; five 

 dorso-central bristles (two prae- and three post- 

 sutural) and four scutellar ; hind tibiae with three 

 pairs of outer bristles ; small species, grey dusted. 

 Gonatherus, Rnd. {planiceps, Fin.) 



22 (21). Antennae as long as the face ; third joint strongly 



pubescent and rounded at its upper corner ; four 

 dorso-central (two prae- and two post-sutural) and 

 two scutellar bristles ; hind tibiae with two pairs of 

 outer bristles ; very slender shining black species. 

 Hexamitocera, Beck, {loxocerata, Ztt.) 



23 (13) (20). Only one sternopleural bristle. 



24 (25). Eyes nearly twice as long (deep) as broad, concave 



behind; frons convex in profile; antennae short; 

 mouth and jowls each with a tuft of four or five 

 black bristles, which are directed almost straight 

 downwards ; pale yellow species. 



488. Leptopa, Ztt. (2207. filiformis, Ztt.) 



25 (24). Eyes nearly as broad as long (deep) ; antennae as long 



as the face ; mouth with only a single forward 

 directed strong bristle on each side. 

 26(27). Third antennal joint broad; frohs convex in profile ; 

 arista distinctly haired ; five dorso-central bristles ; 

 mid sized shining yellow species. Megaphthalma, 

 Beck, {pallida, Fin., with two scutellar and a stig- 

 matical bristle, and four thoracic stripes so run 

 together as to make them appear nearly all brown; 

 unilineata, Ztt., with no stigmatical bristle and four 

 scutellar bristles, and a single brown stripe on the 

 dorsum). 



27 (26). Third antennal joint very long and thin ; frons flat ; 



arista bare; four dorso-central bristles; slender 

 shining black species. 



Micropselapha, Beck, {filiformis, Ztt.) 



28 (4). Palpi long, broad, leaf-like. 



