INSECUTOR INSCITI^ MENSTRUUS 143 



brown. Face gently concave; tubercle distinct, epistoma not 

 produced ; eye margins with fine, whitish pile, silvery pollinose 

 near antennae. Thorax shining black with rather long dirty 

 yellowish pile, side margin and postalar calli with black hairs 

 and bristles ; pleurae with pile somewhat paler than that on 

 mesonotum and with a few black bristles. Scutellum with 

 yellowish pile and with the margin thickly beset with black 

 bristles. Femora shining black, their apices yellowish; tibiae 

 bright yellow with an inf uscate band about middle ; fore tarsi 

 with the first and last joints darkened, the others yellow; 

 middle with only the last joint darkened; hind tarsi with first 

 joint black, the second and last darkened, the others dark 

 yellow. Abdomen shining dark greyish; second and third seg- 

 ments with opaque bands about one-fourth width of a seg- 

 ment on posterior margins ; the pile on the dorsum short dirty 

 yellowish and dark, the sides with fairly long, whitish pile, 

 hypopygium with short black pile. Wings with the costa vein 

 brought well around the tips and the third vein in meeting the 

 end of the costa takes a broad, decidedly downwardly curved 

 direction. Wings with a slight brownish tinge ; stigma luteous. 

 Squamae and cilia pale yellowish white ; halteres dark orange. 

 Length 6-8 mm. ; wing 5-7 mm. 



Female. — Frons shining black, with very short, pale and 

 blackish pile. Antennae bright orange, upper and outer edge 

 of third joint sometimes darkened ; third joint very large, a 

 little longer than broad. Face shining black with the face more 

 prominent than in the male. Thorax with very short, scattered 

 lutescent pile. Scutellum with fewer bristles than the male. 

 Legs marked as in the male. Abdomen entirely shining with 

 very short pale pile. Wings broader than in the male and the 

 third vein with the broad curve. Squamae and cilia whitish, 

 halteres orange. Length 6-7 mm. ; wing 5-6 mm. 



Type.— Cat. No. 25382. U. S. Nat. Mus., male; female 

 allotype. 



Four males and four females; Kukak Bay, Alaska, July 1 

 and 4, 1899, Saldovia, Alaska. July 21, 1899 (Harriman Ex- 

 pedition, 1899, T. Kincaid, collector). 



