10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 66 



4. ARGYRA ANGUSTATA, new species 



Male. — Length. A mm. Slender, wholly dark green, -with little 

 Avhite pollen, and wholly yellow tibiae, femora, and fore coxae. 



Face and front silvery M'hite, the former quite wide. Palpi and 

 proboscis black. Antennae (fig. 5) black; first joint short: I can see 

 only one hair on its upper edge; third joint nearly three times as 

 long as the two basal joints together; arista nearly apical, scarcely 

 as long as the antenna. Orbital cilia wholly pale, except two or 

 three very small black hairs at the top of the eye. 



Dorsum of the thorax and the slender abdomen dark shining 

 green, fore part of the thorax with a little white pollen; scutellum 

 M'ith four large marginal bristles; pleurae blackish with white 

 pollen; hairs on the sides of the first four abdominal segments yel- 

 loAvish. Hypopygium (fig. 7) black or testaceous, the apical half 

 shining and cleft at the apex ; outer lamellae yellow and fringed with 

 hair above ; I do not see any inner appendages, except the long black 

 central filament and its yellow sheath. 



Fore coxae wholly pale yellow ; middle and hind coxae yellow, the 

 latter a little, the former largely, infuscated on outer surface. All 

 femora and tibiae wholly yellow. Fore and middle femora with 

 long, delicate, yellow hairs below. All tarsi infuscated from the tip 

 of the first joint ; first joint of posterior pair brownish-yellow, as long 

 as the second joint. Fore tarsi one and a half, middle ones one and 

 a fourth times as long as their tibiae; joints of anterior pair as 

 54-20-13-13-9. Middle basitarsus as long as the three following 

 joints taken together. Calypters and halteres yellow, the former 

 with a brown tip and yellow cilia. 



Wings nearly hyaline; third vein bent backward at tip; last 

 section of fourth vein a little bent at its middle, parallel with third 

 beyond this bend, ending just back of the tip of the wing; last sec- 

 tion of fifth vein not quite one and a half times as long as the cross 

 vein. 



Female. — Color of the thorax, abdomen, legs, and tarsi as in the 

 male; face ver^^ narrow for a female, about as wide as in the male; 

 face and front silvery white; hairs of the abdomen black, but ap- 

 pearing reddish in certain lights. Those of the male also appear 

 to have a reddish cast. The coxae are yellow with black bristles, 

 the anterior pair a little blackened at extreme base; hairs on the 

 lower surface of all femora yellow, those on anterior pair quite 

 long, those on middle and hind pairs very short. Wings as in the 

 male, except that the bend on the last section of fourth vein is a 

 little nearer the crossvein and the fourth vein ends in the apex 

 of the wing. Joints of fore tarsi as 39-28-18-9-7; middle ones 

 50-22-15-9-6; hind pair 42-15-10-G-7. 



