144 DIPTERA OF NORTH AMERICA. [PART IV. 



Hab. "Washington, D. C ; three female specimens. One of them 

 has the discal cell closed on one of the wings. 



I possess a male specimen which is related to JR. holotrichus, 

 and very like it, but probably distinct : the discal cell is closed ; 

 the veins are darker than the ground color; the antennae are 

 densely pubescent on one side, and with longer verticils on the 

 other ; joints subcylindrical, moderately long ; thorax with two 

 brown lines on the hind part of the mesonotum, before the suture, 

 etc. 



5. R. rutoellus, n. sp. % and 9 • — Thorace rubescente, linea inter- 

 media fusoa ; alis immaculatis ; cellula discoidali aperta, cum tertia 

 posteriori confluente. 



Thorax reddish, with a brown line in the middle; wings immaculate; 

 discal cell open, confluent with the third posterior cell. Long. corp. 

 0.2—0.23. 



Palpi brown ; antennae brownish, the very stout second joint 

 sometimes a little paler ; if bent backwards they would hardly 

 reach the root of the wings ; those of the male have nothing un- 

 usual in their structure ; the pubescence is not very conspicuous, 

 and the verticils of moderate length ; the antennas of the female 

 do not differ much from those of the male. Thorax reddish- 

 yellow, sometimes with a grayish bloom ; a dark brown stripe in 

 the middle ; a row of pale yellow hairs (easily rubbed off) on each 

 side ; halteres pale ; their knob very slightly, often more distinctly, 

 infuscated ; feet brownish, coxae and basis of the femora brownish- 

 yellow ; knees pale. Abdomen brown, with pale yellow hairs ; 

 the last segment and the genitals brownish-yellow ; forceps of the 

 male rather large, its horny appendages black at the tip. Wings 

 (Tab. I, fig. 15) grayish, darker in the region of the stigma; 

 discal cell open, confluent with the third posterior cell ; the latter 

 portion of the seventh longitudinal vein is approximated to the 

 sixth in such a manner that the axillary cell is not broader at the 

 tip than in the middle. 



Hab. West Point, N. Y., in numbers ; Delaware (Dr. Wilson). 



6. R. meigenii 0. S. % and 9 • — Thorace vittis nullis ; alis stigmate 

 obscure fusco ; venis crassis, fuscis ; cellula discoidali aperta, cum tertia 

 posteriori confluente. 



Thorax without stripes ; wings with a dark brown stigma ; veins stout 



