THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 73 



line, whitish but tinged with brown, apical and upper edges rather 

 broadly bordered with black, jagged and bristly at apex, fringed 

 with delicate black hairs on upper edge. 



Coxae black, the anterior pair tinged with green and with thick 

 silvery pollen and very minute white hairs on the front surface; the 

 usual row of bristles at tip are strong. Femora black with green 

 reflections, their tips yellowish, the middle pair has the yellow more 

 extensive and paler. Middle and hind femora each with one preapical 

 bristle, the latter not ciliated but with a row of minute brown hairs 

 on lower outer edge, upper edge fringed with rather long black hairs; 

 these are longest near the base. Fore tibiae blackish, sometimes a little 

 yellowish on apical half. Middle tibae brownish yellow, sometimes 

 quite dark, darker at base on posterior surface, with three large 

 bristles on lower side and three on posterior side; on the upper surface 

 near the middle is a bristle-like appendage (fig. 33a), which is a little 

 shorter than the middle basitarsi and is a little enlarged at tip. 

 Hind tibiae a little thickened, shining black, with three or four large 

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

 joints of decreasing length. Middle tarsi (fig. 336) slender, about 

 once and a half as long as the tibiae; fifth joint about as long as 

 fourth, a little compressed, widened toward the tip; first four joints 

 pale yellow, their tips enlarged and black, each joint narrowed at 

 base. Hind tarsi wholly black, their basitarsi with two large bristles 

 above. Calypters, their cilia, and the halteres yellow. 



Wings grayish (fig. 33), usually tinged with brown along the front 

 for a short distance, from the tip of the second vein toward the base; 

 costa enlarged so as to fill all the space between the costa and the 

 first vein, except a small open spot near the root of the wing, seen 

 from the front edge of the wing this enlargement appears flattened 

 with its tip obliquely truncate, ending in a little point on lower angle, 

 this enlargement velvety black; last section of fourth vein consider- 

 ably bent at its middle; tip of third vein bent backward; hind margin 

 of wing scarcely indented at tip of fifth vein; anal angle of wing 

 very prominent, the wing being of nearly parallel width, but a little 

 wider just before the anal angle than in the middle. 



Female. — ^Differs from the male in having the face wider and more 

 grayish white than silvery; third antennal joint shorter; fore coxae 

 with black hairs; fore and middle tibiae black; middle tarsi olack 

 with the extreme bases of the joints yellowish, tips of first four joints 

 a little enlarged, fifth joint a very little compressed, but not as 

 much as in the male; wings as in the male, except that the costa is 

 not at all enlarged at tip of first vein, the cell between the costa and 

 the first vein is more or less tinged with brown, and the anal angle 

 •of wing is not quite as prominent. 



