94 DIPTERA OF NORTH AMERICA. [PART II. 



and fourth longitudinal veins towards their end almost entirely 

 parallel. 



Hob. New York. (Osten-Sacken.) 



Observation. A single 9 which I possess I believe to be 

 that of the present species. The circumstance that the single 

 bristles of the row on the upper side of the fore tibia? are some- 

 what stronger, the third joint of the antennae much shorter and the 

 arista more distinctly hairy than those of the above described g , 

 cannot justify any doubts, as the females of nearly all the species 

 differ in this way from the males. The only objection which might 

 be raised against their belonging together, is the more whitish 

 color of the dust upon face and front. 



19. Cr. politlis LOEW. 9- Viridis, nitens, faciei albae parte infer!, 

 subtiliter pilosa, fronte albo-pollinosa, antennis ex fusco run's, apicern 

 versus fuscis, coxis pedibusque pallide flavis, alis majusculis ex fusco 

 cinereis, appendicibus analibus duabus styliformibus. 



Green, briglit, the lower part of the white face with delicate hairs, front 

 with a white dust, the brownish-red antenna; brown at the tip ; coxae 

 and feet pale-yellowish; wings somewhat large, brown-grayish; at the 

 end of the abdomen two styloid appendages. Long. corp. 0.14 0.15. 

 Long. al. 0.140.15. 



SYS. Gymnopternus politus LOEW, Neue Beitr. VIII, 34, 18. 



Green, very bright ; the moderately broad face and front covered 

 with white dust ; the lowest part of the face beset with minute pale 

 hairs and a few blackish ones. Antennas, at least for a female, of 

 middle size, dusky brownish-red ; third joint with short but dis- 

 tinct hairs, towards the end blackish-brown and the tip sharply 

 angular. Cilia of the inferior orbit black. Thorax only a little 

 dusty. Upon the scutejlum I cannot perceive any hairs at all. 

 The anal appendages distinguish themselves from those of the 

 related species by consisting of two short black styles. The pos- 

 terior margin of the pleura? is not yellow. Coxa? and feet pale- 

 yellowish. Tarsi but little infuscated towards their tip. The 

 usual row of bristles on the upper side of the fore tibia? rather 

 prominent. Cilia of the tegulas black. Wings rather broad and 

 pretty strongly tinged with brownish-gray. The third and fourth 

 longitudinal veins towards their ends with a slight indication of 

 convergency. 



Hab. New York. (Osten-Sacken.) 



