90 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 51 



Hemiargyra nigra, sp. nov. 



One female, San Carlos, Costa Rica, collected by Schild and 

 Burgdorf. 



Length, 8.5 mm. ; of wing. 8 nun. Blackish, or brownish black. 

 Palpi reddish yellow, quite thickly black-hairy, blackish at base. 

 Space from anterior fronto-orbital bristle to cheek grooves con- 

 spicuously silvery white pruinose as seen from above, covering 

 whole area of parafacials and anterior half of parafrontals, but ap- 

 pearing dead black when seen from below. Facial plate silvery 

 from above, blackish from below. Epistoma yellowish. Third an- 

 tennal joint three and one-half times as long as second. Cheeks 

 brownish, clothed with black hairs; cheek grooves and edge of 

 parafacials bordering suture slightly golden in some lights, brown- 

 ish or reddish in others, the golden continued on occipital orbits. 

 Frontalia, thorax, scutellum, and basal abdominal segment soft 

 black with slight brownish tinge, apex of scutellum silvery. Two 

 middle segments of abdomen heavily golden silvery pollinose seen 

 from in front, behind, qv above, but nearly lost when seen from 

 side ; the coating showing broadly on venter, anteriorly on each seg- 

 ment at least. Sides of middle segments slightly reddish under the 

 pollen. Anal segment black, with some golden pollen on sides and 

 base. Macrochaetse as follows : A median and lateral marginal pair 

 on basal and postbasal segments, a median discal pair on postbasal 

 and preanal segments, the latter with a marginal row, anal segment 

 with only bristly and fine hairs. Wings slightly infuscate along the 

 veins, chiefly on costal half, rest subhyaline. Tegulre smoky, with 

 smoky yellowish borders widening in oblique lights. Pulvilli 

 whitish, with a slight smoky yellowish tinge. Halteres rufous, 

 knobs fuscous. 



Type— Cat. No. 10.907, U. S. N. M. 



POLIOPHRYS, gen. nov. 



Ttilinal suture rounded subangular in middle, its ends divergent 

 below, giving ptilinal area an oval outline that is quite narrowed 

 above and fully one-third head width below. Facial plate elongate, 

 not narrowed below, depressed, produced anteriorly on lower por- 

 tion ; fossae running full length of plate, foveae deep and marking 

 length of third antennal joint; a distinct narrow carina between the 

 foveas, with a linear median furrow on its edge. Facialia wide, but 

 with rather sharp edge, latter gently curved in outline, well inside 

 suture and furnished with bristles extending more than half way up. 

 Vibrissal angles quite distinctly removed from oral margin, not 



