AMERICAN DIPTERA. 293 



Cyrtopogon gibber. 



? Cyrtopogon gibber Williston, Trans. Am. Ent. Soc, XI, 14, PL 



I, fig. 9, 1884. 

 f ? Holopogon ? appendiculatum Bigot, Annales, 1878, 438. 



" 9 • — Length 7 ram. — Dorsum of thorax strongly convex; front much 

 excavated, facial gibbosity slight, posterior tibiae and tarsi thickened. 

 Black; abdomen with narrow interrupted anterior cross-bands and 

 small lateral spots, wings hyaline, cross-vein and costal cell at tip 

 narrowly clouded with dark brown; anterior branch of the third vein 

 angulated. 



"Face in profile only a little convex below, gray pruinose and with 

 whitish bristles on the oral margin of the same color, but more pile- 

 like above. Antennae black; the first two segments of nearly equal 

 length, the third segment not twice as long as the first two together, 

 not very slender, style acute, about half as long as the third segment, 

 the tip with a bristle. Front much excavated on the sides of the 

 ocellar tubercle, which has a few black bristles; pile of the occiput 

 below white; above black. Thorax in profile remarkably convex and 

 high, the convexity being greater on the front part, bare except with 

 four rows of moderately strong bristles; of a rich brown color, with 

 an irregular white stripe on the side in front. Pleurae dark brown 

 lightly pruinose. Scutellum small, bare except two erect black bris- 

 tles at the tip; metanotum thickly white pruinose. Abdomen gently 

 convex, and gently and evenly tapering from the base to the tip, 

 brownish-black, polished, with distinct gray pruinose markings, as 

 follows: On the anterior margin of the second segment with an inter- 

 rupted narrow cross-band, and a little beyond it two narrow trans- 

 verse spots forming an abbreviated interrupted cross-band, near the 

 middle and touching the lateral margin another smaller spot; third, 

 fourth, fifth and sixth segments with an interrupted abbreviated cross- 

 band, and a smaller lateral spot near the middle. Legs black; femora 

 with sparse white pile, tibiae with white bristles; the posterior tibiae 

 considerably thickened gradually from the base, the metatarsi also 

 somewhat thickened. Wings hyaline, all the cross-veins and base of 

 first submarginal cell, and the costa from the tip of second to the tip of 

 fourth vein narrowly clouded with dark brown, a similar cloud at the 

 furcation of the third vein, the anterior branch of which is angulated, 

 and with a minute stump of a vein." 



Type. — University of Kansas. A single female specimen. 



Habitat. — California (type) . 



Dr. Williston appends the following notes: "This species 

 does not belong in Cyrtopogon, but it may be provisionally 

 placed here until a better place is found for it. It shows some 

 relationship to Holopogon, but not as much as to several of 



TRANS. AM. ENT. SOC, XXXV. AUGUST, 1909 



