PROC. ENT. SOC. WASH., VOL. 20, NO. 4, APR., 1918 71 



similar to those on the dorsum, with numerous longer hairs, especially 

 down the center. Hypopygium dull yellow, with numerous, black bristly 

 hairs and a brownish, transverse stripe across the middle of the two basal 

 segments. Legs yellow, tarsi reddish; front and middle femora with a 

 brownish infuscation at, the base, hind femora brownisfy on apical half, 

 the tip yellow r . Wings faintly cinerous; costal edge lutescent on baals 

 half and brown on apical half. 

 Length 12 to 13 mm. 



Described from 3 males. 



Type-locality. El Paso Co., Colorado, June 7, 1914, A. B. 

 Champlain, collector. 



Type Male, Cat. No. 21710, U. S. Nat. Mus. 



STRATIOMYIDAE. 

 Myxosargus nigricormis, new species. 



Near Myxosargus fasciat us, Brauer. 



Male and female.' Black, dorsum of thorax deep bronze. Antennae 

 entirely black. 



Female.- Head, front deep, shiny, blue-black, with numerous dark 

 hairs with a silvery reflection; tubercle near the middle, w r eak and variable; 

 face deep, shiny blue-black, covered with numerous, long, dark-brownish 

 hairs with a silvery-white reflection. Thorax shiny black, dorsum micro- 

 scopically rugose, not so shiny and decidedly bronze colored, with a brown- 

 ish pubescence having a whitish reflection. Scutellum and spines yellow, 

 with a narrow black area across the base of the scutellum. Abdomen 

 shiny black, pubescence with a silvery reflection, pubescence longer on the 

 sides of the abdomen. Halteres pale green, stem brownish at base. Legs 

 black; front knees yellow, middle knees less yellow; apical third of front 

 tibiae, apical half of four posterior tibiae, three basal joints of the four 

 posterior tarsi, yellow. Wings like Myxosargus fascialus, Brauer. 



Wnl<\- Like the female except the dorsum of the thorax is greenish 

 metallic. The pubescence on the front, face, dorsum of thorax and abdo- 

 men, longer and black. Scutellum black, spines yellow. Legs entirely 

 black except apical half of middle tibiae and two basal joints of the four 

 posterior tarsi. 



Length, Female 6 mm., .Male 5.25 mm. 



Type-locality. Chain Bridge, D. C. Described from 22 fe- 

 males and 3 males collected June 10th to July 19, 1912, by the 

 author. Also a female from Plummer's Island, Afd., June 27, 

 1909, collected by Mi'. W. L. McAtee. 



Type. Female, Allotype male, Cat. No. 21711, U. S. Nat. 

 Mus. 



This species was taken on low Tass in a very marshy place. 



