Sept. 1899.] Coquillett: North American Dexid.^^. 221 



Shreveport (June 12, 1891 ; F. W. Mally); and Opelousas (April, 

 1897; G. R. Pilate), La.; Lawrence, Kan. (J. AL Aldrich); and St. 

 Augustine, N. Mex. (T. D. A. Cockerell). Three males and three 

 females. Type No. 4120, U. S. Nat. Museum. A rather slender 

 and elongated form. 



Chsetona bicolor, sp. nov. 



Male. Black, the first two joints of antennse, palpi, apex of proboscis, femora 

 except bases of first two pairs, tibiae and abdomen yellow, base of first segment of 

 abdomen, extending across the segment in the middle of the dorsum, also the narrow 

 apex of each segment, brown. Front at narrowest part scarcely wider than the lowest 

 ocellus, the frontal vitta obliterated for a short distance, frontal bristles descending to 

 base of antennee, no orbital bristles, antennse nearly reaching the oral margin, the 

 third joint three times as long as the second, longest hairs of arista over twice as long 

 as its greatest diameter at the base, sides of face bare, no median carina, cheeks less 

 than one-seventh as wide as the eye-height, proboscis almost half as long as height of 

 head, rather robust, labella rather large. Thorax subopaque, thinly gray pruinose, 

 marked with five indistinct black vitt£e, bearing three prosutural dorsocentral and two 

 sternopleural macrochneta?. Abdomen polished, very thinly gray pruinose, each seg- 

 ment bearing a marginal row of short macrochsetK, the last two also with discal ones. 

 Wings hyaline, tinged with yellow at the base and along the veins, the latter bare, 

 small crossvein at the middle of the discal cell, calypteres yellow. Length, 7 mm. 



White Mts., N. H. A single specimen collected by the late H. 

 K. Morrison. Type No. 41 21, U. S. Nat. Museum. 



Chaetona nitens, sp. nov. 



Female. Black, the labella yellowish. Front two-thirds as wide as either eye, 

 frontal bristles descending below middle of second antennal joint, two pairs of orbital 

 bristles, antennre reaching the oral margin, the third joint very strongly pubescent, 

 four times as long as the third, longest hairs of arista only slightly longer than its 

 greatest diameter at the base, sides of face bare, extremely narrow, no median carina, 

 facial ridges straight, diverging below, vibrissse near the oral margin, one or two bristles 

 above each, cheeks scarcely one-tenth as broad as the eye-height, proboscis about 

 one-fourth as long as height of head, very robust, labella unusually large. Thorax 

 polished, the sides anteriorly and the pleura white pruinose, three postsutural dorso- 

 central and two sternopleural macrochceta;. Abdomen polished, the front angles of 

 the last three segments white pruinose, these segments bearing only marginal macro- 

 chastse. Wings distinctly smoky on the costal half, the remainder nearly pure hyaline, 

 third vein bearing one or two bristles near the base, veins elsewhere bare, small 

 crossvein at middle of discal cell, hind crossvein midway between the small and bend 

 of fourth vein, the latter arcuate, apical cell open, ending at the extreme wing-tip ; 

 calypteres whitish. Length, 3.5 mm. 



Franconia, N. H. A single specimen collected by Mrs. A. T. 

 Slosson, Type No. 4122, U. S. Nat. Museum. 



