NEW GENERA AND SPECIES OF MUSCOID FLIES. By Charles H. T. Townsend, Custodian of Muscoid Diptera, United Stales National Museum. During the past year or two many new forms of muscoid flies have been described by the writer, and the manuscripts placed with various serial publications. A large part of the descriptions has already been published, but a considerable portion of them has not yet appeared. The present paper contains descriptions of the most noteworthy remaining new muscoid genera thus far studied in the United States National Museum collection. Tlie forms here treated are from North and South America, Eurasia, and Malaysia, with one from Australia. Family MUSCIDAE. TRONGIA, new genus. Genotype. — Trongia viridis, new species. Seems to approach Catajncephala, differing in f acialia thi<3kly ciliate with ordinary bristles to a little above middle, and head but slightly broader than the thorax. Strong approximated proclinate ocellar bristles. One strong reclinate imier orbital bristle in male; inner verticals cruciate, outer almost as long as imier. Vertex about one-sixth head-width. Oral margin very prominent; the strong vibrissae practically on same, and not narrowing the facial plate. Third antennal joint six or seven times second, narrow, of even width, rounded apicaUy. Arista plumose almost to tip. Claws slender, extremely long, almost twice last tarsal joint. Two strong median marginal macrochaetae on second segment; marginal row of strong ones on third and fourth segments. Hypopygium not prominent. Cubitus subangular, last section of fourth vein evenly bent in, apical cell open well before wingtip. Proboscis short and fleshy. Tegulae bare. TRONGIA VIRIDIS, new species. Length of body, 13.5 mm.; of wing, 11.75 mm. One male, Trong, Lower Siam, February, 1899 (W. L. Abbott). All metallic green; face and front lightly golden or brassy, cheeks silvery; antennae, palpi and pulviUi pale fulvous, the third antennal Proceedings U. S. National Museum. Vol. 5I-No. 2152.