14 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



PSILOPUS FLAVIANNULATUS, new species 



Male. — Length 5 mm.; of wing the same. Face blue with green 

 reflections, more violet just below the antennae, covered with silvery 

 white pollen when viewed obliquely, its suture near the middle. 

 Front blue or violet. Palpi and proboscis yellow. Antennae yel- 

 low, third joint mostly brown, small, a little pointed at tip, second 

 joint with a crown of short bristles; arista dorsal, scarcely as long 

 as the width of the head. 



Dorsum of thorax shining green with blue or violet reflections; 

 bristles of thorax and abdomen short, those on posterior part of 

 thorax a little longer; scutellum with one large and one small pair 

 of bristles. Abdomen green, first segment mostly yellow, second 

 yellow at base, the others with black incisures and coppery reflec- 

 tions. Hypopygium (fig. 23) dark brown with long outer append- 

 ages, which are yellow with a black tip, the inner appendages 

 blackish. 



All coxae, their bristles and hairs and all femora and tibiae yel- 

 low; all femora nearly bare below; middle femora with a row of 

 short but stout black hairs on apical half of posterior surface ; tibiae 

 without bristles, except very short ones near the base of fore and 

 middle pairs; fore and middle tarsi blackened from the tip of the 

 first joint, posterior pair wholly blackish; fore tarsi with a row of 

 short, flattened hairs, which do not reach the base or tip, fifth joint 

 very slightly widened; other tarsi plain, except that the middle 

 ones have short, delicate, but rather dense hair below on third and 

 fourth joints. Joints of fore tarsi as 135-29-24-16-7; of middle 

 ones as 132-48-40-21-10; joints of posterior pair as 98-il-26-15-8. 

 Calypters and halteres yellow, the former with a black tip and 

 long pale cilia. 



Wings grayish hyaline; costa ciliated with erect hairs, which are 

 bent at tip and begin near the middle of first vein, they become short 

 recumbent hairs before the tip of second vein; first vein not one- 

 third the length of the wing; crOss vein oblique; last section of fifth 

 vein 17, cross vein 53 ; fourth vein from the cross vein to the fork 53, 

 from fork to wing margin nineteen-fiftieths of a millimeter long; 

 fork of fourth vein bent backward so as to make less than a right 

 angle with basal part of fourth vein, upper bend of fork with a stump 

 vein. 



Female. — Thorax less blue; bristles of fore coxae brown; costa 

 without cilia, the hairs being all recumbent; tarsi plain. 



Described from 2 males and 10 females, taken by Nathan Banks, 

 July 6 and August 8, 1924, at Bella Vista, Panama Canal Zone; and 



