558 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



blackish vittae, the inner pair shorter. Abdomen pale yellow, heavy 

 median vitta blackish; anal segment and irregular posterior half of 

 third rufous ; hind border of second pale smoky-rufous ; anal segment 

 thinly silvery pollinose, showing more densely on base and sides. 

 Femora and tibiae tinged with rufous. Wings tinged with smoky- 

 yellowish on costal half or so. Tegulae glassy. 

 Type.— C&t. No. 22237, U.S.N.M. 



Tribe EUTHELAIUmi. 

 PARATHELAIRA, new genus. 



Genotype. — ParatJielaira panamensis, new species. 



Clypeus well sunken. Epistoma rather short, abruptly warped. 

 Facialia bare. Proboscis very short ; palpi long and slender. Third 

 antennal joint two and one-half times second in male. Arista much 

 longer than antennae, thin, bare. Eyes bare. Male vertex about 

 one-seventh head width. One frontal below base of antennae. No 

 proclinate fronto-orbitals in male. Ocellars very weak. Parafacialia 

 narrow, bare. Cheeks little over one-sixth eye length. Two sterno- 

 pleurals; three postintraalars, postsuturals, preacrostichals, posta- 

 crostichals, and lateral scutellars; no apical scutellars. Costal spine 

 present. Third vein bristled only at base; others bare. Apical cell 

 open a little before tip. Hind crossvein a little nearer cubitus. Male 

 claws long. Median marginal pair on first two segments; median 

 discal pair on intermediate segments, marginal row on last two seg- 

 ments; submarginal and two discal rows on anal segment. 



PARATHELAIRA PANAMENSIS, new species. 



Length, 9.5 mm. One male, Porto Bello, Panama, February 25, 

 1911 (A. Busck). 



Brownish, silver}'" pollinose. Palpi, basal half of antennae, para- 

 facialia, anterior half of paraf rontaiia, and base of last three abdominal 

 segments pale fulvous; these parts all silvery pollinose except palpi 

 and antennae. Four dark thoracic vittae, the inner pair a little 

 narrower. Wings faintly and evenly smoky-yellow. Tegulae glassy- 

 whitish. 



Type.—Cat. No. 22224, U.S.N.M. 



LYDELLOTHELAIRA, new genus. 



Genotype. — LydelloiJielaira collaris, new species. 



Clypeits rather deeply sunken. Epistoma short; nearly in clypeal 

 plane. Facialia strongly ciliato over halfway. Proboscis very short ; 

 palpi heavy, wide, short, bowed. Third antennal joint about triree 

 and one-half times second in male. Eyes bare. Male front well over 

 one-fourth head width. Two frontals below base of antennae, but 

 in straignt line. Two proclinate fronto-orbitals in male. Ocellars 



