8 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



tibia ; fore and middle tarsi with snow-white hairs on lower surface 

 of last two joints, those on middle tarsi very conspicuous; joints of 

 fore tarsi as 84-23-17-10-7 ; those of middle ones as 107-27-20-10-6 ; 

 joints of posterior tarsi as 71-24r-17-10-8. Calypters and halters 

 brown, the former with black cilia. 



Wings grayish; first vein reaching nearly to the middle of the 

 wing; venation very much like that of longipennis, new species, 

 except that the fork of fourth vein is at nearly right angles to 

 fourth vein, not being bent backward. 



Described from one male, taken by Nathan Banks, August 8, 1924, 

 at Bella Vista, Panama Canal Zone. 



Type. — In the Museum of Comparative Zoology. 



PSILOPUS LONGIPENNIS, new species 



Male. — Length 5.2 mm.; of wing 6 mm. Face dark green with a 

 little brown pollen at lower edge, the suture a little above the middle. 

 Front shining green with blue reflections, especially below. Palpi 

 and proboscis black. Antennae black, short, bristles of second joint 

 but little longer than its width, third joint rounded; arista nearly 

 apical, as long as width of head. 



Thorax blue-green ; scutellum with two pair of bristles. Abdomen 

 green with basal half of second, third, and fourth segments dull black, 

 fifth and sixth segments mostly brown; bristles of thorax and abdo- 

 men moderately long. Hypopygium brown, lamellae (fig. 13) black 

 with the base yellowish, they are enlarged at tip with a broad notch 

 on one side and a few long hairs at tip. 



Coxae and femora black, fore coxae and lower surface of all fe- 

 mora with long white hair; fore and middle tibiae dark yellow, 

 posterior pair more brown; all tarsi brown or black; tibiae almost 

 without bristles, posterior ones with conspicuously long hair; last 

 joint of fore tarsi a very little widened; second, third and fourth 

 joints of hind tarsi slightly enlarged, so as to appear thick; middle 

 basitarsus (fig. 14) with little bristles on one edge, which are rather 

 scattering and on the other edge a close-set row of blunt and slightly 

 clavate hairs, which are shorter than the bristles on the other side; 

 joints of fore tarsi as 108-30-26-14-11 ; of middle ones as 141-27-22- 

 11-6; those of posterior pair as 100-21-21-15-10. Calypters brown- 

 ish, their cilia black; knobs of halteres yellow. 



Wings (fig. 15) grayish; long and rather narrow; costa with rather 

 long recumbent hair; first vein reaching nearly to the middle of the 

 wing; fourth vein from the cross vein to the fork 74, from fork to 

 wing margin 28, cross vein 48, and last section of fifth vein twenty- 

 three fiftieths of a millimeter long. 



Described from a male taken by Nathan Banks, August 1, 1924, 

 at Barro Colorado Island, Panama Canal Zone ; he also took another, 



