AMERICAN DIPTERA. 337 



WILLISTONIISA n. gen. 

 ? Habropogon Williston, Trans. Am. Ent. Soc, XI, 10, 1SS4. 



" In structure, except the head, throughout like species of 

 Stenopogon, but less pilose. Head considerably broader than 

 high, but scarcely as wide as the thorax. Face very narrow, 

 the eyes separated by an extremely narrow interval from the 

 antennas ; their inner margins above and below gently diverg- 

 ent, so that the distance between the angles below is a little 

 greater than that above. Face in profile gently concave from 

 antennas to oral margin, nearly perpendicular, wholly bare, 

 except a thin short row of bristles on the oral margin, which 

 is projecting as in species of Stichopogon, Deromyia, and Sar- 

 opogon; front only gently excavated, widened above. An- 

 tennae (PI. IV, fig. 5) short, first two segments of equal length, 

 third a little longer than the first two taken together, broad, 

 scarcely more than twice as long as wide, obtusely pointed at 

 the tip and with a very small, almost microscopic style; beard 

 short and thin. Thorax bare, except with very minute hairs, 

 and moderately strong, no abundant bristles on the posterior 

 portion; scutellum with four bristles. Abdomen slender, 

 elongate, cylindrical, broad at the base. Fore and middle 

 femora with two posterior preapical bristles, and the pos- 

 terior femora with an anterior row of bristles. Fourth pos- 

 terior cell nearly closed." Fore tibias without a terminal 

 claw-like spur. 



Type. — Habropogon bilineatus Williston. 



In a recent exchange of insects with Dr. F. Hermann of 

 Germany, I received a specimen of Habropogon longiventris 

 Loew, and knowing that Dr. Williston of the University of 

 Chicago, had described (loc. cit. above) a new species which 

 he referred doubtfully to Habropogon, I took the liberty of 

 sending him my specimen for comparison. Although his type 

 was at the University of Kansas, he wrote in reply concerning 

 the European Habropogon " it is generically very distinct 

 from my Habropogon bilineatus in the structure of the face 

 especially. I fear that the latter will require a new generic 

 name. H. bilineatus is nearest to Stichopogon in structure of 

 head, but differs chiefly in the front and the antennas." Dr. 



TRANS. AM. ENT. SOC, XXXV. (43) AUGUST, 1909 



