22 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



fore and middle femora black with narrow yellow tips; posterior 

 femora without the cluster of bristles at their middle and with only 

 one bristle at tip; tibiae and tarsi pale yellow, plain, tarsi a little 

 darkened toward their tips; last section of fifth vein 31, cross vein 

 twelve-fiftieths of a millimeter long. 



Described from two males and one female, taken by J. M. Aldrich, 

 April 16, 1926, at La Providencia, Obispo, Guatemala. 



r^/pe.— Male, Cat. No. 40136, U. S. N. M. 



This is very much like Achradocera Tneridonalis Becker ^ which 

 has the middle tibiae and basitarsi formed about the same; but ac- 

 cording to Doctor Becker that species has the face dull brown; the 

 cilia of the calypters black; tibiae and tarsi yellow, at least the de- 

 scription does not mention the inf uscation of the tips of fore and mid- 

 dle tibiae and of all tarsi, except their base, which is very conspicuous 

 in this form; his figure shows less constriction of the tibiae and no- 

 large bristle above ; in Tneridonalis the hypopygial lamellae are blacky 

 in this they are yellow. 



CHRYSOTUS FLAVIMACULATA, new species 



Male. — Length 3-4 mm. Face narrow, a little wider above, white ; 

 palpi as long as width of third antennal joint, silvery white; front 

 shining, green or bronze color; antennae wholly black, third joint 

 rounded at tip, not as long as wide ; arista apical ; lower orbital cilia 

 white. 



Thorax shining green, the anterior half more or less reddish cop- 

 pery; pleurae dulled with white pollen. Abdomen shining green 

 with coppery reflections on basal half; second segment with a large 

 yellow triangle on each side, which are widely separated on the dor- 

 sum or sometimes they may meet above; hypopygium small, blacky 

 appendages small. 



Fore coxae, and all femora, tibiae, and tarsi yellow, tarsi darkened 

 at tip ; posterior edge of pleurae and most of hind coxae yellow ; fore 

 coxae nearly bare with black bristles at tip ; fore femora with longer 

 hair below than above; fore tibiae without bristles, those of middle 

 and hind ones large ; pulvilli of fore tarsi yellow^, distinctly enlarged ; 

 joints of fore tarsi as 39-21-15-11-7; those of posterior pair as 27— 

 23-15-8-6. 



Wings grayish; third and fourth veins parallel, fourth ending in 

 the apex of the wing ; cross vein in the middle of the wing ; first vein 

 reaching a little more than half way to tip of second; last section 

 of fifth vein 27, cross vein eighteen-fif tieths of a millimeter long. 



Described from five males, taken by Nathan Banks, July 8-27, 1924. 

 at Barro Colorado Island, Panama Canal Zone. 



Type. — In the Museum of Comparative Zoology. 



1 Becker's Dolichopodidate of America, 1921, p. 20S. 



