williston: Brazilian diptera. 45 



tinctly shorter than the second, rather broad at the base; style small, 

 attenuate. Face, cheeks and the lower part of the occiput wholly 

 light yellow. Thorax opaque black ; a whitish poUinose spot on the 

 inner side of each humerus ; vertical pleural pollinose spot not dis- 

 tinctly limited above ; a row of dorso-pleural, at least two prescutellar, 

 and four scutellar, well-developed bristles. Abdomen subopaque 

 black; second segment yellow at the base; sixth segment opaque 

 golden yellow pollinose. Wings brownish before the third longitudi- 

 nal vein, the first basal and the first posterior cells wholly hyaline ; a 

 streak before the fifth vein. Legs deep brown ; the base of all the 

 tibiae, the large pulvilli, and the claws (except their tips) yellow. 



Length 12 millimeters. One specimen, Chapada, H. H. Smith. 

 This species is peculiar in its narrow front, bristles of the thorax, and 

 hyaline first posterior cell. 



5. Oonops nobilis, n. sp. 



Female. Head black ; front, below the vertical callosity, except a 

 crescentic space above the base of the antennae, opaque ; face, on the 

 sides and in the depression, with a conspicuous, light yellowish silvery 

 reflection ; in an oblique light from above the ground-color wholly 

 concealed. Antennae black; the reddish first joint about two-thirds 

 the length of the third joint; the third joint about two-thirds of the 

 length of the slender second joint ; third joint of the style with a short 

 bristly extremity. Thorax black, lightly pollinose, opaque ; on the 

 front margin, and near the humeri, velvety ; in the middle in front 

 distinctly whitish when seen from behind. Abdomen black, subshin- 

 ing ; second segment deep opaque black, save on the anterior part, 

 where it is whitish pollinose; ventral process of the fifth segment 

 small. Legs black ; the tarsi and claws (save their extreme tips) light 

 yellow; pulvilli very large, yellow; the tarsi dilated. Wings unequal- 

 ly brown in front, scarcely extending beyond the third vein, save in the 

 first posterior cell; the costal cell and the outer part of the wing in 

 front of the third vein of a lighter color. 



Length 12 millimeters. One specimen, Chapada, H. H. Smith. 



G. Conops inornatus, n. sp. 



Male. Front black, shining, the vertical callosity reddish. Face 

 yellow, with golden pollen on the sides extending up on the lower part 

 of the front. Cheeks wholly yellow. Thorax black, shining, lightly 

 pollinose ; margins of the thorax and of the scutellum with moderately 

 large bristles. Abdomen slender, black, shining; the narrow hind 

 margins of the third and fourth segments, the fifth on the sides and 

 behind, and the sixth nearly wholly, light golden pollinose. Legs 

 brown; base of tibiae yellow; basal joints of the tarsi yellowish. 



