566 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



short and rather slender. Third antennal jomt about three times 

 second in male; rather narrow. Arista moderately long-pubescent 

 halfway. Eyes bare. Male vertex hardly one-seventh head width. 

 One frontal below base of antennae. No proclinate fronto-orbitals 

 in male. No ocellars. Parafacialia very narrow, bare. Cheeks 

 scarcely one-sixth eye length. Two sternopleurals, postsuturals, 

 and postacrostichals; three postintraalars, preacrostichals, and 

 lateral scutellars; no apical scutellars. Third vein bristled only at 

 base, others bare. Apical cell open just before tip. Hind crossvein 

 a httle nearer to cubitus. Tarsi and claws long in male. Median 

 marginal pair on first two segments, marginal row on last two. 



OPSOLESKIA FLAVA, new species. 



Length, 7 mm. One male, Bartica, British Guiana, June 4, 1901 

 (through C. W. Johnson) . 



Fulvous-yellow. Frontalia brown. Third antennal joint and 

 arista tinged with fuscous. Palpi pale yellow. Rest of head silvery, 

 shading to golden on front. Thorax rather thickly pale golden 

 pollinose; four dark vittae, the inner pair narrow, the outer ones 

 widely interrupted. Abdomen whoUy light yellowish, appearing 

 bare in direct view but showing thin pollen coat in oblique view. 

 Legs fulvous. Wings slightly tinged with fuscous, more so on outer 

 half. Tegulae glassy-yellowish. 



Type.—Csit. No. 22240, U.S.N.M. 



Tribe VORIINI. 

 OESTROPLAGIA, new genus. 



Genotype. — Oestroplagia petiolata, new species. 



ClyiDeus only shghtly depressed. Epistoma short, slightly warped. 

 Facialia ciliate about or nearly halfway above vibrissae. Proboscis 

 short; palpi club-shaped. Second antennal joint elongate; the third 

 no longer than second. Arista short, bare, basal joints short. Eyes 

 bare, the inner border sinuate in male. Frontals in three rows in 

 male, descending four bristles below base of antennae. No proc- 

 linate fronto-orbitals in male. Ocellars present. Parafacialia bare. 

 Cheecks one-fourth eye length. Several geno-orbitals. Four sterno- 

 pleurals, postsuturals, and lateral scutellars; three postintraalars, 

 preacrostichals, and postacrostichals. A weak suberect nondecus- 

 sate apical pair of scutellars. Costal spine strong. Third vein 

 bristled only at base; others bare. Apical cell petiolate far before 

 tip; the petiole nearly twice as long as small crossvein. Cubitus 

 nearly in middle of wing breadth, with strong stump. Posterior 

 crossvein nearly its length from cubitus. No median marginals 

 on first segment; median marginal pair on second; marginal row on 

 third; discal row on anal with marginal and submarginal bristles. 



