THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 93 

 No. 51. DOLICHOPUS SEDULUS, new species. 



Male. — Length, 4-5 mm. ; of wing, the same. Face wide, covered 

 with dark yellowish pollen, which is sometimes a little golden, at 

 others more brownish. Front shining green, antennae black, first 

 joint very slightly yellowish on the lower apical angle (this color 

 may be caused by pollen) ; third joint not longer than wide, somewhat 

 orbicular in outline, obtusely pointed at tip. Lateral and inferior 

 orbital cilia white; there are about six black cilia on each side above. 



Thorax almost coppery brown on the anterior portion, more green 

 posteriorly, with rather thick brown pollen on the front two-thirds 

 of the dorsum, which leaves shining vittae or spots; pleurae dulled 

 with white pollen. Abdomen green with narrow black incisures and 

 bronze reflections, wholly covered with white pollen, which is thickest 

 on its sides. Hypopygium black; its lamellae (fig. 51a) moderately 

 large, somewhat orbicular in outline, but tapering into the stem and 

 a little flattened at tip, white with rather narrow black border on 

 apical margin, where they are jagged and bristly, fringed above with 

 delicate but long black hairs. 



Coxae black with yellow tips ; anterior pair with white pollen and 

 little black hairs on the front surface. Fore femora black, shading 

 into yellow at tip; middle femora mostly yellowish, black at base 

 and along upper and lower edges for a greater or less distance, with 

 one preapical bristle and often a smaller one a little nearer the base; 

 hind femora black, their inner surface more yellow, with one pre- 

 apical bristle, without cilia below but fringed with rather long black 

 hairs on upper edge. Tibi-ae yellow; posterior pair black at tip for 

 nearly one-fourth their length, slightly thickened, a more or less 

 distinct brown line on the innel" side of central portion, the glabrous 

 stripe on upper surface broad, extending from the outer row of 

 bristles, well upon the inner surface so as to include the inner row of 

 bristles. Fore tarsi a little longer than their tibiae, black from the 

 tip of the fii'st joint, this joint fully as long as the three succeeding 

 taken together; fourth and fifth joints of nearly equal length, third 

 a little longer. Middle tarsi about one and a fourth times as long 

 as their tibiae, black from the tip of the first joint. Hind tarsi 

 wholly black, about one and a third times as long as their tibiae. 

 Calypters and halteres yellow, the former with very black cilia. 



Wings (fig. 51) gi-ayish, slightly darker in front; costa with a slight 

 knot-like enlargement at tip of first vein, still tapering a little to its 

 tip; last section of fourth vein a little bent at or just beyond its 

 basal third, sometimes it is a little more sharply bent and bears a 

 stump of a vein at the posterior angle of the bend ; hind margin of 

 wing scarcely indented at tip of fifth vein; wing of rather parallel 

 width, the anal angle being prominent. 

 187329—21 7 



