58 AMERICAN BLACK FLIES OR BUFFALO GNATS. 



mid and hind tarsi (PI. V, fig. 3). AVings slightly grayish, thick 

 veins brown. Ilalteres yellow. 



Frons divergent-sided, above antennae more than half as broad as 

 at upper angle of eyes, surface hairs brown, upright, and regularly 

 distributed; face not as long as frons and slightly longer than broad, 

 surface hairs pale and shorter than those on frons; hairs on palpi 

 pale; postocular cilia pale, with an admixture of brown hairs. 

 Scutum with white i3ilosity, w^hich is short, close-lying, and regular 

 except on margins, where it is rather longer and looser; a few short 

 brown upright hairs are present on lateral anterior angles and many 

 longer ones on posterior fourth; pleural tuft grayish white; scutellum 

 with close-lying white pilosity and long, upright, brown marginal 

 hairs. Abdominal basal scale brown, fringe white; segments of 

 abdomen almost bare, only a few scattered brown hairs present, those 

 on apical segments most distinct. Legs with close-lying, short, pale 

 pilosity and longer, brown, upright hairs on dorsal surfaces ; the nor- 

 mal paired apical hairs present on the fore tarsi and longer hairs also 

 on hind tarsal joints 2-3; hind tarsi with basal joint produced and 

 second joint with basal scale and constriction (PL V, fig. 5) ; claws 

 with sub-basal tooth (PI. II, fig. 11). Venation of wings normal 

 except that the cross-vein is at slightly beyond middle of subcosta ; 

 hairs on basal jDart of wing brown, anal marginal hairs white. 



Length, 3^ mm. 



Redescribed from the two type specimens from Las Vegas, N. Mex., 

 August (H. S. Barber). These have the scutum indistinctly reddish 

 and differ in this respect only from a series in the collection from 

 Los Angeles, Cal., which was taken in June and July. I can find no 

 other characters which would justify me in separating them as dis- 

 tinct species. 



Male. — Opaque black-brown. Face white-dusted ; antenna? brown, 

 basal two joints yellowish; palpi black-brown. Scutum with two 

 distinct silvery-white stripes on dorsum; these stripes are anteriorly 

 slightly convergent and terminate with an outward curve on anterior 

 margin of scutum; they do not extend posteriorly beyond the last 

 fourth of disk; lateral margins and anterior angles of scutum white- 

 pollinose; pleurae white-pollinose; postscutum with silky, white polli- 

 nosity. Abdomen opaque black at base, apical three segments slightly 

 shining, first segment below basal scale and fifth almost entirely 

 silver}^ white, venter yellowish laterally. Legs yellow, blackened as 

 follows: Mid and hind coxa:'; apices of all femora and tibiae as well 

 as slightly at base of latter; entire fore tarsi; apices of basal joint of 

 mid and hind tarsi; apical four joints of mid and all but base of 

 second joint of hind tarsi. Wings grayish, thick veins brown. 

 Halteres with clear yellow knobs and darkened stalk. 



