SYRPIIID7E. 89 



()(i. Iliiid til)ia> of the male witli an internal median spur. (See also Mal/ofa 



sp.) Teiichocnemis Osten Sacken. 



Hi!ul tibiiv of $ not with such a spur. Polydontomyia Williston. 



07. Hind femora thickened and witli a liitid spur below (?North America). 



Senogaster Macquart. 

 Hind femora without such spur. ....... 08 



08. Slender species; abdomen narrowed basaliy. (See 28.) 



Abdomen in no wise club-shaped. ...... 09 



09. Thorax with distinct yellow markings other than on the humeri. 78 

 'i'horax not with distinct yellow markings of the ground color other 



than rarely on the humeri. ....... 70 



70. Face transversely arched or carinate, not produced, not tuberculate; 



abdomen more or less elongate and nearly bare. ... 71 

 More or less thickly pilose species, often large. . . . . 7o 



71. Hind femora extraordinarily thickened; anterior cross-vein rectangu- 



lar Sykitta St. Farg. and Serville. 



Hind femora more or less thickened ; crf)ss-vein oblique. . . 72 



72. Face sharply carinate. ..... Tropidia Meigen. 



Face transversely arched Xylota Meigen. 



7;). Scutellum, margin of the thorax and ])leura^ with bristly hairs. 



Ciirysochlamvs Kondani. 

 Thorax wholly without bristles. ....... 74 



74. Face short, not produced, concave from antenna? to tip, not tuberculate ; 



hind femora thickened 7.') 



Face produced, long. ......... 7fi 



75. Al)domon elongate. .... Uuacuypai.its Macquart. 

 Abdomen very broad; thorax densely pilose; middle femora of the $ 



with an inferior basal sjjiir. . . . IIadromyia Williston. 



70. Face produced forward, pointed, concave from antenna? to tip, not 



tuberculate; hind femora thickened. Crioit.ora Osten Sacken. 



Face not evenly concave, but tuberculate or convex. ... 77 



77. Third joint of the antenna? produced aliove into a conical ])rocess, ter- 



minating in the tiiickened arista. . . Mekaimoidi s liigot. 



Third joint of the antenna? obliquely oval ; hind femora rarely tiiick- 

 ened. ....... CiiioRiiiNA Macquart. 



78. Hind femora with a conical, tooth-like jirotubt ranee below near the 



distal end. ....... Si-ilom^ia Meigen. 



Hind femora without .<uch ]>r()tnberance. ..... 79 



11 



