OF WASHINGTON". 91 



the first two, black; the antennae and tarsi except their bases brown; 

 head rounded, lostrum broader than long; body somewhat polished; 

 wings hyaline, apex of first vein considerably before the forking of the 

 fourth, lower end of the small cross-vein before the forking of the fifth 

 vein. Length 2.5 mm. 



A female specimen from San Marcos, Nicaragua. 

 Type. No. 7792, U. S. National Museum. 



Family BIBIONID^. 



Dilophus fumosus, n. sp. 



Black, the front coxae, and the front and middle femora, except their ex 

 treme ends, yellow (hind femora, tibiae and tarsi wanting); hairs black; 

 rostrum narrow and elongate, longer than the eyes, the antennas inserted 

 at one-fourth of the distance from the base; front tibiae bearing a pair of 

 spines on the posterior side at one-third length of tibiae, an oblique row 

 of four spines at the middle and a row at the apex; wings pale brown, the 

 costal cell and stigma dark brown. Length 6 mm. 



A male specimen from Granada, Nicaragua. 

 Type. No. 7793, U. S. National Museum. 



Dilophus rhynchops, n. sp. 



Black, the first antennal joint, front coxae, their trochanters and femora, 

 also basal half of hind femora, yellow (middle legs wanting): hairs black; 

 rostrum about as long as the eyes, antennae inserted at one-fifth of its 

 length; body polished; spines of front tibiae as in fumosus; wings hya 

 line, costal cell smoky, stigma brown. Length 3 mm. 



A male specimen from Granada, Nicaragua. 

 Type. No. 7794, U. S. National Museum. 



Family THEREVID^. 

 Psilocephala pruinosa, n. sp. 



Black, the first two joints of antennae, the halteres, femora, tibiae and 

 base of tarsi, yellow, venter of abdomen except at base, and the geni- 

 talia, reddish yellow, frontal triangle and face whitish pruinose, the 

 tubercle above the antennas and pair of tubercles below them polished ; 

 first joint of antennae rather slender, slightly longer than the other 

 two taken together; thorax gray pruinose, scutellum at base velvet 

 black, the remainder gray pruinose, bearing four bristles; abdomen dor- 

 sally silvery-white pruinose, prolonged ventrally at the hind angles of 

 the second and third segments, the broad hind margins of these segments 

 white, hairs of abdomen and pleura chiefly white; wings hyaline, the 

 base and costal cell yellowish, a brown cloud in base of first posterior cell 

 and on cross-vein at base of the second, a large, indeterminate brownish 



