24 PKOCEEDINGS OF THE NATIONAL. MUSEUM vol.83 



ately long black hairs, -which extend downward below base of 

 antennae; frontals about six in number, descending almost to level 

 with apex of second antennal segment, directed inward, the upper- 

 most pair reclinate, not very long; ocellars strongly divergent, pro- 

 clinate; orbitals absent; inner verticals strong, outer ones not devel- 

 oped; face gray pollinose, its ridges normally divergent downward, 

 bare except a few bristly hairs above vibrissae, which are on a level 

 with the protruding front edge of mouth ; sides of face below base 

 of third antennal segment without any hairs between the row of 

 bristles and margin of eye; cheeks gray pollinose, sparsely haired 

 below, about two-fifths the eye height ; antennae black, third segment 

 reddish near base, about four times the length of second ; arista black, 

 thickened to middle; palpi brown, bearing several long black hairs 

 near tip ; eyes distinctly hairy ; back of head clothed with pale hairs. 



Thorax and scutellum black, covered with dense gray pollen; 

 mesonotum with four very distinct black stripes, outer pair inter- 

 rupted at suture and stopping before base of scutellum; chaetotaxy 

 as in V all diner vis ^ except that there are three pairs of well-developed 

 acrostichal bristles before the suture; postscutellum normal, gray 

 pollinose; one hair present on each side of postnotum beneath the 

 calypters ; the latter semitransparent, white. 



Abdomen black, covered with gray changeable pollen, which in 

 most views extends to the hind margins of last three segments ; basal 

 segment without median marginals; second with one pair; third 

 bearing a marginal row, the intermediate bristles poorly developed; 

 fourth with a discal and a marginal row of rather stout bristles; 

 genital segments blackish, subshining. 



Legs black ; claws and pulvilli elongated ; the latter dark or grayish 

 in color. 



Wings subhyaline; hind cross vein sinuous, oblique to fourth, 

 joining it nearer bend than small cross vein; apical section of fifth 

 vein one-half the length of preceding section; apical cell narrowly 

 open well before tip of wing; third vein setulose as usual; costal 

 spine developed ; epaulets black. 



Female. — Front at extreme vertex 0.291 of the head width (one 

 specimen); two pairs of strong proclinate orbitals; outer verticals 

 about half as large as inner pair; third antennal segment moderately 

 wide to tip, about three and one-half times as long as second; fore 

 tarsal segments normal, the claws and pulvilli distinctly developed. 



Length. — Male, 7.5 mm ; female, 8 mm. 



Type.—MoXe, U.S.N.M. no. 44761. 



ReTnarks. — Described from one male and one female. Las Vegas, 

 N.Mex., July (Cockerell). 



