120 DIPTERA or NORTH AMERICA. [PART IV. 



ish-3'ellow, which color is more saturate, almost ferruginous, along 

 the anterior margin ; there is a fringe of black hairs along the 

 costa, between the tip of the first longitudinal vein and the apex 

 of the wing ; the surface of the wing is slightly infuscated along 

 this fringe ; veins finely pubescent ; the discal cell is at least 

 three times longer than it is broad ; the prtefurca is not longer 

 than this cell. 



Hah. Dalton, Ga. ; a single male specimen, taken by me in 

 1859. 



Some remarks about the male forceps of this species (Tab. lY, 

 fig. 11) will be found in the description of the plates of the male 

 genitals, at the end of this volume. 



Gen. X. ORIMARGA. 



One submarginal cell ; four posterior cells ; discal cell open, coalescent 

 7vith the second posterior cell ; great cross-vein about the middle of the icing, 

 and hence, the fourth posterior cell vary long (Tab. 1, fig. 9). Tibire without 

 spurs at the tip; empodia distinct. i\ntenn8e 16-jointed. Basal pieces 

 of the male forceps elongated, slender, with horny, slender, claw-shaped 

 appendages at the tip ; upper valves of the ovipositor small, slender, 

 pointed. 



Rostrum projecting, cylindrical, much shorter than the head ; 

 eyes large, glabrous ; front comparatively narrow. Collare ex- 

 tended in a somewhat elongated neck; mesonotum moderately 

 convex, rather narrowed anteriorly ; mesosternum very long. 

 Feet long and slender, apparently glabrous (the pubescence 

 being microscopic) ; the usual excision between the two last 

 tarsal joints, on the under side, exists here in the male. Abdo- 

 men elongated, narrow. Wings elongated, rather narrow (Tab. 

 I, fig. 9). The auxiliary vein ends in the costa a little distance 

 anterior to the inner end of the submarginal cell and at a con- 

 siderable distance beyond the origin of the second longitudinal 

 vein (this distance being more than one-third of the breadth of- 

 the wing) ; the tip of the auxiliary vein is stout and runs 

 obliquely into the costa which, at and beyond that point, seems 

 to be slightly incrassated ; the subcostal cross-vein immediately 

 precedes the tip of the auxiliary vein ; the first longitudinal vein 

 reaches far beyond the tip of the auxiliary vein and ends in the 

 costa at a point which is distinctly nearer to the apex of the wing 

 than to the tip of the auxiliary vein ; the second longitudinal vein 



