26 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 81 



mostly black; tip of second and base of third antennal joints reddish, 

 this color extending to the middle of the third on inner side ; third 

 antennal joint three times the second, rather wide, at its middle 

 almost twice as wide as the paraf acial, somewhat prominent at base 

 and tip on the front side, leaving a distinct concavity between, the 

 apex truncate, reaching nearly to vibrissae. Arista with penultimate 

 joint a little elongate, barely twice as long as thick, the apical joint 

 rather short, thickened nearly to the middle. Eyes with long pile. 

 Cheek a little more than one-fourth the eye height. Palpi slender, 

 yellow apically, dark brown on basal half; outer verticals distinct, 

 three-fourths as long as the inner. Mesonotum with rather thin 

 silvery-gray pollen, leaving four longitudinal shining black stripes, 

 the inner narrow and reaching halfway from the suture to the scutel- 

 lum; an elongate median spot before the scutellum. Acrostichal 

 3, 3; dorsocentral, 3, 3; sternopleural, 2, 1. Scutellum, with 3 lateral 

 bristles, a small erect nondecussate hairlike apical pair. Propleura 

 and prosternum bare. Second and third segments of abdomen of 

 same color as thorax, in some lights showing pollen to the apices of 

 the segments ; fourth segment with more yellowish pollen, the ground 

 color rather dark red ; first segment with no median marginals, second 

 with one pair, third with a median pair and two or three at the 

 margin; second and third segments with a single pair of discals 

 much smaller than marginals; fourth segment with a median row 

 of six large bristles and a marginal row of the same number con- 

 siderably smaller. Genitalia red, small, very similar to those of the 

 other species ; the inner forceps blackish, being united into a beaklike 

 process curved upward and acute at tip; outer forceps slender, 

 curved like the inner with a minute tooth at apex. Legs black, all 

 the tarsi rather short and decreasing in width. All the claws and 

 pulvilli very small. Front tibiae with two bristles near middle on 

 postero ventral side; middle tibiae with four bristles on anterodorsal 

 side, the two middle ones quite long, and with one ventral; hind 

 tibiae with an uneven sparse row on anterodorsal side. Wings hya- 

 line, the first vein hairy to tip from humeral cross vein; third vein 

 with coarse hairs nearly to cross vein; fourth vein with rounded 

 almost rectangular bend, then concave, reaching costa only a little 

 before apex. The first posterior cell open. Hind cross vein 

 straight, somewhat oblique, joining fourth vein considerably beyond 

 middle of the distance between anterior cross vein and bend. Calyp- 

 ters white, the hind ones subtransparent ; inf rasquamal setules present 

 but delicate. 



Length, 6. 5 mm. 



Female. — Front at vertex 0.27 of the head width. The pollen on 

 upper two-thirds much more distinctly yellow than in the male. 

 Third antennal joint more than twice the second, distinctly wider 



