SYRriTID.'R. 87 



:1S. Mak'S holoptif. Sykphus Fabricius. 



Malt's broadly dii-luiptif. .... Cn-i^MOSYRPHrs Mik. 



;W. Dorsuni of tliorax with a iiu'diaii ciiiorious liiu'; ocelli usualh' remote 

 from the vertex. ...... Mesoc.ramma Loew. 



Dorsum of tliorax without sueh line. ...... 40 



40. Eyes of $ with an area of eiilarf^ed facets al)ove; fourth segment of 



the abdomen with two median yellow stripes and oblique side-spots. 



^^LLOGRAPTA ( )sten Sackeu. 

 Ej'es of $ not with an area of enlarged facets above; fourth abdom- 

 inal segment not so marked. ....... 41 



41. Face projecting below ; slender speiies. Spha;rophoria Macquart. 

 Face receding; abdomen oval. . . Xantiiogbam.ma Schiner. 



42. Thickly pilose species; abdomen black, the basal jiortion light-col- 



ored. ........ Lki'cozona Schiner. 



Thinly pilose species, not so marked. ...... 4;! 



4;!. Hind femora thickened. ......... 44 



Hind femora slender. ......... 47 



44. Species wholly or chiefly reddisli or lutescent 4(i 



Black species, sometimes with luteous sjiots on face, humeri, and basal 

 angles of the abdomen. ........ 45 



4i"). Scutelluin unusually large, nearly square in outline; males dichoptic. 



CiiALtOMYiA ^\'illiston. 

 Scutelluni oval ; males liolo])tic. . . . Mviomcpta Newman. 



4(i. Face carinate ; abdomen oval. . . . Brachyopa Meigen. 



Face tuberculate Hammkrsciimidtia Schummel. 



47. Epistoma i)roduced into a long jxirrected snout. Bhixoia Scojtoli. 



Epistoma not produced. ..... Chilosia Meigen. 



48. Third longitudinal vein Vicnt deeply into the first posterior cell. 51 

 'I'hird longitudinal vein not bent deej)ly into the first posterior cell ; 



antennae clongfite. . 48 



49. Arista very densely {)lumoKe, a[)pearing as a solid mass. 



CopKSTvr.vM Macquart. 

 Arista feathery plumose. ........ 5U 



50. Males dichoptic. ..... Mkoametapon Giglio-Tos. 



Males holojitic. ...... Voia'CKLLA Geofl'roy. 



51. Hind femora with a sharj) tooth-like projection below near the ilistal 



end. ........ Mii.KSiA Latreille. 



Hinil femor;i without such tooth. ...... 52 



