THE DIPTEROUS GENUS DOLICHOPUS IN NORTH AMERICA. 55 



wings more strongly tinged with brown; otherwise about as in the 

 male. The middle basitarsi without a bristle above. 



Redescribed from 12 males and 9 females. Pacific Grove, Cali- 

 fornia, May 9 (J. M. Aldrich); Monterey, California, July 17, and 

 Pine Lake, southern California (Johnson); Palo Alto, California, 

 June 3 (M. C. V.); Hood River, Oregon, June 8 (Cole). 



Type locality. — ^Monterey, California. 



Type. — American Museum of Natural History; it has been 

 examined. 



No. 18. DOLICHOPUS TETRICUS Loew. 



Dolichopus tetricus Loew, Mon. of N. Amer. Dipt., pt. 2, 1864, p. 33. 



Hale. — Length, 4.5 mm.; of wing, 4 mm. Face rather wide, a 

 little narrowed below, yellowish gray. Front green. Antennae 

 wholly black (Doctor Loew states that the third joint is "almost 

 round, still with a sharp projection at tip." The third joint is now 

 missing in the male type). Lateral and inferior orbital cilia yellowish 

 white, a few of the upper cilia black. 



Thorax and abdomen dark green, the latter with coppery reflec- 

 tions. Hypopygium black; its lamellae of moderate size, elliptical 

 in outline, whitish with a black border on apical and upper margins, 

 jagged and bristly at apex. 



Coxae black, anterior pair with black hairs and a very little white 

 pollen on their front surface; femora and tibiae black. Fore and 

 middle femora with apical third, hind ones with apical fourth yellow. 

 Middle and hind femora each with one preapical bristle, the latter 

 ciliated for nearly their whole length on lower inner edge with blackish 

 hairs, the longest of which are about as long as the width of the 

 femora. All tibiae yellowish at extreme base; posterior pair dis- 

 tinctly but not greatly thickened, but a little more so at tip; when 

 viewed in the right direction they appear a little narrowed in the 

 middle. Fore tarsi (fig. 18) a little longer than their tibiae; their 

 basitarsi black, except at extreme tip, which is yellowish, about as 

 long as the two following joints taken together; second and third 

 joints yellowish; fourth black, a little more than half as long as third, 

 perhaps very slightly compressed but scarcely so; fifth joint black, 

 compressed, about as long as third and nearly as wide at tip as long, 

 somewhat obcordate. Middle tarsi about one and a fourth times as 

 long as their tibiae, the first joint more than half as long as the tibiae 

 and with a large bristle near apical fourth. Hind tarsi wholly black. 

 Calypters and halteres yellow, the former with black cilia. 



Wings grayish; costa not at all enlarged at tip of first vein; last 

 section of fourth vein considerably bent near its middle; third vein 

 bent backward a little toward its tip; hind margin rather evenly 

 rounded, not indented at tip of fifth vein; anal angle rather promi- 

 nent. 



