AST. 10 TROPICAL. AMERICAN" DIPTERA VAN DUZEE 13 



a little above the antennae, its suture at the middle. Front green or 

 blue-green, shining, except just above the antennae and at the vertex. 

 I can see but one or two very small yellow liairs on each side. 

 Antennae black; third joint small, second joint with one bristle 

 below that is longer and one that is shorter than the antenna, those on 

 upper edge of joint shorter ; arista dorsal, about as long as the width 

 of head. Palpi black with black hair ; proboscis yellowish brown. 



Thorax and abdomen shining green; dorsum of thorax with a 

 little white pollen, which is visible when viewed obliquely; bristles 

 of thorax black, of moderate length; scutellum with two pair of 

 large bristles; abdomen with the base of second to fifth segments 

 black; sixth segment mostly blue; hairs and bristles of the abdomen 

 short, black, those on the basal half of the venter short and whitish. 

 Hypop3'gium (fig. 21) and its lamellae shining black, the latter thin, 

 nearly as large as the former, sometimes curled up so as to appear 

 slender. 



All coxae and femora and the hind tibiae black; fore coxae with 

 rather short white hairs; all femora with long white hair below; 

 tips of fore and middle femora, their tibiae and basitarsi yellow; 

 fore and middle tarsi from the extreme tip of first joint and the 

 whole of posterior tarsi black; fore tibiae with two small bristles 

 on basal third of upper surface and two a little larger on lower 

 posterior edge; middle tibiae with two rather small bristles on basal 

 third and one at apical third of upper surface and four or five very 

 small ones below ; hind tibiae with several very small bristles ; first 

 joint of fore tarsi (fig. 22) with three long bristles below, one at 

 base and two erect ones on apical half, second joint with six minute 

 bristles below. Joints of fore tarsi as 59-17-17-11-8 ; those of mid- 

 dle ones as 56-23-18-11-7; joints of posterior pair as 62-23-17-10-7. 

 Calypters and their cilia black, knobs of halteres yellow. 



Wings (fig. 29) grayish with the usual brown crossbands con- 

 nected on the costal margin; the hyaline space between them ex- 

 tends to third vein and is continuec^in front of it in a space where 

 the brown is paler than that around it, which does not reach the 

 second vein; hairs on the costa very short and recumbent. 



Female. — Like the male in color, except that the abdomen is more 

 bronzed ; the posterior tibiae are sometimes brownish yellow and all 

 tarsi are a little paler, the fore basitarsi have the same bristles 

 below, but they are much shorter, not being longer than the diame- 

 ter of the joint. 



Described from 23 males and females, all taken by Nathan Banks, 

 June 20 to August 7, 1924, at Barro Colorado Island, Panama Canal 

 Zone. 



Type. — In the Museum of Comparative Zoology. 



Paratypes.—^l^Xft, female. Cat. No. 41032, U.S.N.M. 



