doliciiopodid.t:. 79 



1(). The face of the male extends below the eyes, hanging down before the 

 moutli, apron-like Polymedon Osten Sacken. 



The face of the male reaches as far down as tlie lower edge of the 

 eye 17 



The face of the male does not reach so far as the lower edge of the 

 eye IS 



17. Third antennal joint of the male rudimentary, the long arista with a 



disk at the end MA CELL O fiint ^ Mik. 



Antenna? of simple structure. . . Tachytrechus Stannius. 



18. Tliird and fourth veins towards tlie tip parallel or nearly so. . 10 

 Third and fourth veins toward the tip distinctly convergent. . 20 



19. First antennal joint bare above, third joint elongate in the male. 



I'elokopeodes Wheeler. 

 First joint hairy above Gymnopternus Loew. 



20. The last segment of tlie fourtii vein gradually approaching the third. 



Hercostomus Loew. 

 Last segment near the middle abruptly curving forward, then grad- 

 ually resuming its former course, making a segment of a circle, the 

 concavity outwards, and ending near the tliird vein. ^ 



Pakaclius Bigot. ^ iaT^ 



21. Costal vein extending to tip of third vein, the latter part of tlie fourth 



vein evanescent or partially so. . . . Asyndetus Loew. 



Costal vein extending to the \\\\ of the fourth vein, wliich is of the 



usual strength. ......... 22 



22. Sixtii vein wanting (minute species, not sliining, the first vein reaching 



only a fifth of the length of the wing). . . . Achalcls Loew. 

 Sixtli vein present, at least for a short distance. ... 23 



23. P^irst antennal joint liairy above. ...:.. 24 

 First antennal joint bare above. ....... 29 



24. Second antennal joint with a thumb-like projection fitting into the 



inner side of the third Syntormox Loew. 



Secorttl antennal joint witlioiit such jirojection 25 



2.J. Fourth vein before tlie tip sharply curved toward the third, nearly 



reaching it at the margin, . . META.iJJiivASTON'i^fHTis Ahlrich. 



Fourth vein near the end iiarallel with the third or only nioderatidy 



convergent. •......-.. 2(5 



2(5. Arista dorsal, third antennal joint of usual size, pali)i of male large, 



face wide. . I)iostraci;s Loew. 



Arista dorsal, palpi small, face very narrow. . Anepsius Loew. 

 Arista nearly or (luite at the end of the large, jiointed third joint. 27 



