THE DIPTEROUS GENUS DOLICHOPUS IN" NORTH AMERICA. 157 

 No. 108. DOLICHOPUS RENIDESCENS Melander and Brues. 



Dolichopus renidescens Melander and Brues, Biol. Bull., vol. 1, p. 143. 



Male. — ^Length 4.5-5 mm.; of wing the same. Face very wide 

 and short, yellowish brown. Front violet, green along the orbits 

 and lower edge, sometime wholly blue-green, shining. Antennae 

 wholly black; third joint a little longer than wide, obtusely pointed 

 at tip; palpi dark yellow with black hairs. Lateral and inferior 

 orbital cilia white, about six to eight of the upper cilia on each side 

 black. 



Thorax dark shining green, still the dorsum is slightly dulled with 

 almost invisible brown pollen; pleurae dulled with white pollen. 

 Abdomen dark green with slight bronze reflections and a little white 

 pollen on its sides. Hypopygium black; its lamellae (fig. 108a) 

 of moderate size, somewhat triangular in outline, white with wide 

 black border on apical margin, which is jagged and bristly. 



Fore coxae yellow with a blackish spot at base on outer side, their 

 anterior surface with rather numerous black hairs. Middle and 

 liind coxae black with yellow tips. Femora and tibiae yellow. Mid- 

 dle and hind femora each with two preapical bristles, placed one before 

 the other, the latter ciliated on apical half of lower inner edge with long 

 black hairs, the hairs being inserted rather widely apart, the longest 

 about as long as the width of the femora. Posterior tibiae a little 

 thickened, black at tip, more extensively so on inner side, where the 

 black sometimes reaches three-fourths their length, the yellow usually 

 reaching the tip on the lower surface; on most of the inner surface 

 the hairs are very minute, giving it the appearance of being glabrous. 

 Fore tarsi a little longer than their tibiae, black from the tip of the 

 first joint, which is nearly as long as the three following joints taken 

 together, fifth joint shorter than tliird and longer than fourth. Mid- 

 dle tarsi one and a fourth times as long as their tibiae, black from the 

 pit of the first joint, which is without a bristle above. Middle tibiae 

 with a large bristle before apical third and two small ones just before 

 it on the lower surface. Hind tarsi fully one and a half times as long 

 as their tibiae, wholly black. Calypters and halteres yellow, the 

 former with black cilia. 



Wings (fig. 108) grayish, usually strongly tinged with brown in 

 front of third vein; costa with small enlargement at tip of first vein; 

 last section of fourth vein a little bent before its middle; hind margin 

 of wing a little indented at tip of fifth vein; wings of rather parallel 

 width, still a little narrowed from tip of sixth vein to the anal angle, 

 which is prominent; the hind margin is a little sinuous between the 

 tips of fifth and sixth veins, forming a small lobe near sixth. 



Female. —Face nearly the same width as in the male, yellowish 

 gray; hind femora without cilia below; hind tibiae a little tliickened, 

 187329—21 11 



