10 



33 (30) Eyes equally hairy above and below 



(never spotted or banded), or with 

 dark bands, which are formed by 

 hair alone ERISTALIS, p. 92. 



34 (23) Marginal cell broadly open. 



35 (38) Hind femora simple, without a tooth- 



like process beneath at end ; sub- 

 apical cross-vein not recurrent. 



36 (37) Eyes bare HELOPHILUS, p. 94. 



37 (36) Eyes hairy MALLOTA, p. 98. 



38 (35) Hind femora with a distinct tooth-like 



process ; subapical cross-vein recur- 

 rent MERODON, p. 100. 



39 (22) Third vein not kinked, or rarely with 



a slight undulation ; marginal cell 

 open. 



40 (45) Second autenual joint short, as 



usual. 



41 (42) Face with a distinct tubercle ; third 



vein with a deep kink ; eyes of 

 male widel} r separated ; hind femora 

 thickened and spiuoe beneath .... CHASMO.MMA, p. 102. 



42 (41) Face carinate or flat, without tubercle ; 



third vein straight or rarely undu- 

 lating but not loop-like ; eyes of male 

 usually touching. 



43 (44) Face carinate ; subapical cross- vein 



not recurrent and without appendi- 

 culated angles ; scutellum of ordinary 

 size and not indented ~. SYRITTA, p. 104. 



44 (43) Face flat ; subapical cross-vein recur- 



rent and usually with appendiculated 

 angles ; scutellum of greater size and 

 often indented EUMEHUS, p. 108. 



45 (40) Second antermal joint enormously 



elongate, being the longest of all . . AMPHOTEHUS, p, 116. 



46 (1) Antennas long and porrect, very often 



longer than the head ; if rarely they 

 are short and pendulous, there is a 

 stump on the third longitudinal vein 

 down the middle of the subapical 

 cell ; there are never macrochaetae 

 on thorax and scutellum. 



47 (52) Antennae with a dorsal arista and 



usually not placed on a long petiole ; 

 small cross-vein before the middle 

 of the discal cell. 



48 (49) Third vein without a stump ; subapical 



cross-vein not recurrent ; thorax and 

 abdomen always adorned Avith yellow 

 markings CHKYSOTOXUM, p. 118. 



49 (48) Third vein with a stump; subapical 



cross- vein recurrent or at least per- 

 pendicular ; abdomen usually with- 

 out yellow markings scutellum often 

 spinose. 



