OF WASHINGTON, VOLUME XVII, 1915 159 



of segments very narrowly yellowish, most noticeably so on the posterior 

 lateral angles. Legs entirely yellow. Wings clear, veins fuscous. 



Frons slightly wider than either eye; triangle very large, occupying 

 the entire frons with the exception of a narrow stripe on each side of 

 nearly same width as the anterior ocellus extending almost to the anterior 

 margin, where the sides converge, forming a rather obtuse apex; frontal 

 hairs weak; those on the lateral submarginal line of triangle most dis- 

 tinct; third antennal joint large, slightly longer than broad, rounded at 

 apex; arista almost bare, slightly longer than width of frons anteriorly; 

 profile of head slightly retreating towards mouth; cheeks linear, barely 

 distinguishable. Disc of mesonotum with short, rather closely placed, 

 blackish hairs; scutellum rather short, less noticeably flattened and more 

 rounded than in most species of the genus, disc with several short black 

 hairs, the apical pair of bristles rather widely separated, not cruciate. 

 Legs slender; fore tarsi not broadened; sensory area on hind tibiae half the 

 length tibia. Inner cross vein of wing distinctly before apex of first vein; 

 third and fourth veins almost straight; penultimate section of fourth vein 

 about a third as long as ultimate section of fourth and subequal to last 

 section of fifth. Length, 1-1.5 mm. 



Type locality: Monticello, June 30. Paratypes from Center- 

 ville, August 16, and Mohamet, August 6, all in Illinois. 



C. grata Loew differs from parviceps in having the frontal tri- 

 angle gradually tapering from vertex to anterior margin, the 

 cheeks nearly as broad as third antennal joint, the scutellum con- 

 spicuously flattened, bare, with noticeable "rim," and the apical 

 pair of bristles closely placed and generally cruciate; also differs 

 in several minor respects. 



Genus GAURAX Loew. 



Through a mistake in selecting the type of the genus Neogaurax 

 the writer, in the paper already referred to, inadvertently created 

 a synonym of Gaurax, as its type possesses the generic characters 

 of Neogaurax. It thus becomes necessary to rename the genus 

 which contains the forms having the scutellum much elongated, 

 flattened dorsally, and ending in an obtuse point, and I here pro- 

 pose for it the name Pseudogaurax, with the genotype Gaurax 

 unchora Loew. 



In describing 2 new species of Gaurax I take the opportunity of 

 presenting a synoptic key for the separation of the described 

 species of the genus. I am indebted to Prof. J. M. Aklrich for an 

 opportunity to examine a specimen of G. eph/i>/>inni from Mrs. 

 Slosson's collection. I have added dot-tali* Loew and /n'loxula 

 Becker to the species already included in the genus as lliey ob- 

 viously belong there. I have taken the former in Illinois, but the 

 latter I have not seen. I am indebted to Professor Aklrich for in- 



