124 INSECUTOR INSClTIit MENSTRUUS 



median pair approximated and heavier, a bristle between them, usually 

 no distinct peiir of bristles behind them but sometimes a weak pair. Three 

 stemopleural, three postsutural, three postacrostichal, and two preacrosti- 

 chal bristles, but sometimes only one acrostichal both before and behind 

 suture. 



Proboscis a little shorter. Palpi microscopically tubercular, or repre- 

 sented only by minute bristlets. Third antennal joint one and one-eighth 

 to one and one-half times as long as second. Male front at vertex about 

 equal to eye-width or slightly narrower, that of femaJe about one and 

 one-third times eye-width. 



Reproductive habit, probably leaf-larviposition of colored maggots. 



Type, Eusignosoma aureum, new species. 



Eusignosoma aureum, new species. 



Length of body, 8.5 (male) to 10.5 mm. (female); of wing, 8 to 10 

 nrni. Two males and one female, Uruhuasi Bridge, San Gaban Canyon, 

 about 6,500 feet, February 15, 1910, on flowers of Baccharis sp. 



Head pale golden pollinose, the parafrontals dusky with same pollen ; 

 frontalia light reddish-brown. First two antennal joints reddish, being 

 about same shade as frontalia or slightly deeper ; third joint brown to 

 blackish, arista black. Male front at vertex equal to eye-width. Occip- 

 ital and parafacial pile pale brassy, parafrontal pile black. Base and inner 

 or lower edge of third antennal joint is more or less reddish, broadly so 

 in female. Thorax dark, thickly pale brassy pollinose, leaving same vittae 

 as in Signosomopsis argentea. Scutellum and abdomen wholly black 

 except the deep golden poDinose marking of anal segment. Venter 

 wholly blackish. Scutellum and venter rather shining, the tergum nearly 

 opaque. Disk of scutellum with irregular weak spinelike macrochaetae. 

 First abdominal segment with macrochaetae only at sides. First three 

 segments with rather long thickly placed bristles on sides which graduate 

 into the shorter thick black pile of disk. Golden pollinose marking of 

 anal segment not reaching sides of segment, with median posterior pointed 

 tongue, one or two pairs of macrochaetae in its disk or nearer to its pos- 

 terior edge. AnaJ segment as long as other segments together measured 

 on median line. Legs very light reddish or rust-yellowish ; the anterior 

 and middle tarsi but slightly paler in male, concolorous in female. Front 

 tarsi of female slightly widened. Wings evenly infuscated, bases narrowly 

 smoky-yellowish ; hind tegulae deeply infuscate, front tegulae smoky- 



