34 PEOCEEDINGS OF THE NATIONAL MUSEUM vol.72 



Front, at vertex, 0.34 of the head width, the narrowest point being 

 directly across the anterior ocellus ; the entire front of the head and 

 the posterior orbits are silvery poUinose, the frontal stripe, however, 

 brown. In this specimen the reddish ground color of the paraf acials, 

 facial ridges, and cheeks shows through to a noticeable extent and 

 the suture is distinctly bordered with a darker tinge to its lowest end. 

 Frontal bristles in a single row, the hairs below the lowest are black, 

 as are also the hairs of the cheek. Face considerably depressed in 

 the middle, the vibrissae about the length of the second antennal joint 

 above the oral margin ; facial ridges with well-developed bristles up 

 to a point above the middle of the third antennal joint. Antennae 

 black, second joint more dark brown, with a tinge of red at the junc- 

 tion with the third, which is three times as long as the second and a 

 little tapering. Palpi dark yellow, cheek almost half the eye height, 

 beard white. 



Thorax brownish black with usual thin pollen more distinct in 

 front. Scutellum brown, with four pairs of bristles, the median pair 

 of the same appearance as the others. The disk has about a dozen 

 depressed small bristles. Calypters brown. Sternopleurals 4 on one 

 side, 5 on the other. 



Abdomen black, with faint reddish tinge at the sides; third seg- 

 ment with only a very narrow basal interrupted, white, poUinose, 

 crossband, hardly more than a line ; fourth segment with dense pale 

 yellow pollen, the apical third black. 



Legs black, front pulvilli slightly longer than last two tarsal 

 joints; hind tibia on outer side with a row of small, suberect bristles 

 mixed with a few hairs not so bushy in appearance as in many 

 species. 



Wing brown throughout, narrow at apex, bend of fourth vein rec- 

 tangular and rounded, its distance from the hind margin less than 

 half of that to the large cross vein ; third vein with two bristles. 



Genitalia smaller than in most of the species, the inner forceps 

 black, closely pressed together near tip and bent forward almost with 

 an angle; outer forceps hardly so long, dark yellow in color, flat 

 and bluntly rounded at tip. 



Length, 10 mm. 



Kepresented in the National Museum by two females from Ypi- 

 ranga, Sao Paulo, Brazil ("Fonseca leg."). In these the single row 

 of frontais is as characteristic as in the male, and they have four 

 proclinate orbitals in a row, rather far from the eye. The pollen 

 on the parafrontal becomes very thin or almost absent on an oval 

 area that does not include the frontais but touches the eye near the 

 vertex; this area is more or less subshining black, but less in one 

 specimen than the other. The vertex is 0.40 of the head width, the 

 same in both. 



