INSECUTOR INSCITL^ MENSTRUUS 173 



an olive shade. Median traingle of black on second segment, 

 and one on first segment reversed. Bases of third and anal 

 segments silvery-white and bare of microchsetae. Tegulse 

 nearly white. Wings faintly evenly smoky, well tinged with 

 yellow. 



Polygastropsis, new genus. 



Genotype, Polygastcr brasilicnsis Townsend, 1917, Bull. Am. 

 Mus. N. H., xxxvii, 224-325. 



Differs from Polygastcr by having fifth vein bristled nearly 

 to hind crossvein, as well as in the other characters given in 

 the description of the genotype. 



Thelairophasia, new genus. 



Genotype, Thelairophasia transita, new species. 



Allied to Thelaira and Masiphya. Epistoma well produced 

 below vibrissse, strongly warped and nasute. Clypeus scarcely 

 depressed. Facialia flattened nearly to plane of clypeus. 

 Third antennal joint of male long and bulged on front 

 border. Arista long, slender, microscopically pubescent. 

 Two verticals and three reclinate orbitals in male. Parafacialia 

 bare, narrowing below, as wide as facialia. Apical cell open 

 well before tip. Median discals on intermediate segments, a 

 strong median marginal pair on first segment. 



Thelairophasia transita, new species. 



Length, 8 mm. One male, Rio Charape, Jaen Province, 

 Peru, 3,700 feet, September 10, 19n (C. H. T. Townsend). 



Brownish. Face and cheeks pale golden pollinose, para- 

 frontalia deeply golden. Frontalia dark brown. Third anten- 

 nal joint blackish, second joint rufous. Palpi pale fulvous. 

 Mesonotum dull golden pollinose ; four thoracic vittae, inner 

 pair very narrow. Bases and sides of last three abdominal 

 segments silvery with pale golden tinge, most of disk of seg- 

 ments appearing brown pollinose in oblique view. Tegulse 

 pale watery-yellowish. Wings nearly clear. 



