86 DIPTEEA OF NORTH AMERICA. [PART III. 



usual; ocelli very near the edge of the vertex, rather large, but 

 little approximated ; the four bristles on the edge of the vertex 

 rather strong; the lateral, as well as the ocellar bristles replaced 

 by shorter, bristle-like hairs. Antennae of the coloring of the 

 body, almost reaching to the anterior edge of the oral opening; 

 arista bare. Face but moderately concave, somewhat retreating 

 on the under side, pollinose with white, except in the vicinity of 

 the oral opening; in the well-marked foveae this pollen is thicker 

 and more conspicuous; the lateral portions of the face, bordering 

 on the eyes, are very narrow and likewise clothed with white 

 pollen. Eyes much higher than broad ; cheeks narrow. Clypeus 

 of a moderate breadth, distinctly projecting over the edge of the 

 mouth ; palpi not very broad, almost ferruginous. Proboscis 

 rather stout; occiput moderately turgid. The whole thorax and 

 the convex scutelluin shining, with a very faint trace of a reddish 

 metallic reflection. Scutellum with six bristles. Abdomen of a 

 metallic reddish-violet coloring, which, in a different light, assumes 

 upon the first three segments a bronze-green tinge; this is not 

 the case with the last segment. Front feet with the coxas 

 brownish-black; on the four posterior feet the tibiae and tarsi 

 alone have this coloring; the coxae and femora have the color of 

 the thorax. Halteres yellowish-red, with an infuscated knob. 

 Wings hyaline, with brown veins, which are not in the least 

 sinuous; their anterior margin has a conspicuous, but unequal 

 brown border, which, near the apex, extends as far as the fourth 

 vein ; from the root of the wing to the small crossvein, which is 

 still included in this border, it becomes gradually broader and 

 reaches here almost to the fifth longitudinal vein; it contracts 

 immediately beyond the small crossvein, to the second longitu- 

 dinal vein ; opposite the posterior crossvein it expands again 

 towards the third longitudinal vein, and runs immediately behind 

 this vein as far as the apex of the wing, where it suddenly turns 

 towards the fourth longitudinal vein, which forms the limit of this 

 dark border; the very steep posterior crossvein projects in an 

 unusual way beyond the fourth longitudinal vein; it is bordered 

 with brown ; this border forms a narrow, perpendicular cross- 

 band, which growing paler and more indistinct, extends to the 

 dark border of the anterior margin, or quite near it; the costal 

 cell is clay-yellow, except at the basis and at the tip, which are 

 more brownish. The marginal and submarginal cells are re- 



