20 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



of second ; last section of fifth vein 37, cross vein twenty-five fiftieths 

 of a millimeter long. 



Described from one male taken by Nathan Banks, July 13, 1924, at 

 Barro Colorado Island, Panama Canal Zone. 



Type. — ^In the Museum of Comparative Zoology. 



This form is remarkable for the color of its legs. 



Genus ASYNDETUS Loew 



Asyndetus Loeav, Centuries, 8, 1869, No. 58; Beschr. Europ. Dipt., vol, 2, 

 1871, p. 296.— Wheeler, Proc. California Acad. Sci., vol. 2, 1897, p. 

 32.— Aldbich, Kansas Univ. Sci. Bull., vol. 1, 1902, p. 87.— Van 

 DuzEE, Psyche, vol. 23, 1916, p. 88 ; Ent. News, vol. 30, 1919, 248. 



ASYNDETUS FLAVITIBIALIS, new species 



Female. — Length 4.5 mm. Face about as wide as the front, nar- 

 rowed a little below and quite pointed, covered with whitish pollen, 

 its suture below the middle. Palpi large, yellow with pale hairs; 

 proboscis black ; front blackish, covered with whitish pollen. Anten- 

 nae wholly black, third joint nearly round, a little flattened at tip: 

 arista dorsal, as long as the face. Orbital cina and beard white. 



Thorax and abdomen green with coppery reflections, the former 

 with two coppery lines on the dorsum; hind margins of abdominal 

 segments broadly and densely white pollinose; bristles of thorax 

 and tibiae black; all hairs of abdomen, coxae, femora, tibiae and 

 tarsi yellow. 



Coxae and femora greenish black, extreme tips of coxae, the 

 trochanters, base and tips of femora, all tibiae and tarsi yellow, 

 tips of fore and middle tarsi and most of last four joints of posterior 

 tarsi infuscated; joints of fore tarsi as 22-7-6-5-5; of middle tarsi 

 as 44r-18-14-8-9 ; joints of posterior tarsi as 35-39-22-12-11. Calyp- 

 ters and halteres yellow, the former with white cilia. 



Wings grayish, veins yellow, costa brownish yellow; third vein 

 straight and parallel with second vein to tip of that vein, then 

 bending sharply backward, so as to run nearly parallel with costa 

 and uniting with it at about three-fourths the distance from tip 

 of second vein to the apex of wing ; fourth being quite strong for the 

 genus, broken opposite tip of second vein, the last part overlapping 

 the basal part and parallel with it, but not quite reaching the wing 

 margin, which it would touch far back of the apex of the wing; 

 cross vein placed opposite apical fifth of first vein. 



Described from two females, taken by A. Busck, February 15, 

 1912, on Tabogilla Island, Panama. 



Ty^e.— Female, Cat. No. 41035, TJ.S.N.M. 



This would run to latus Van Duzee, but differs in being larger, 

 in having the fourth vein stronger and completely broken, third 



