18 PROCEEDINGS OF THE NATIONAL MUSEUM vol.73 



Male. — Front at vertex 0.37-0.39 of the head width, widening from 

 about the level of the posterior ocelli. Frontal bristles in three irreg- 

 ular rows, with two pairs of proclinate orbitals. Parafrontals with 

 yellowish pollen anteriorly, most of their surface subshining and rather 

 dark, a little translucent. Face, parafacials, cheeks and posterior 

 orbits silvery white, the small hairs below the frontals white; cheek 

 with white hair. Antennae reddish-yellow about to arista, remainder 

 more blackish. Third joint hardly three times the second. Arista 

 decidedly flattened almost to the apex, which is more blunt than 

 usual. Vibrissae not far above the edge of the mouth, the distance 

 being about half the length of the second antennal joint. Facial 

 ridges with 6 or 7 bristles extending up almost to the level of the 

 arista. Palpi yellow; beard white. 



Thorax black, with rather uniform thin gray pollen. Scutellum 

 reddish. 



Abdomen red in ground color at the sides, black in the median 

 portion; second segment with changeable yellowish pollen which is 

 thin and almost invisible over most of the surface, leaving the shining 

 red and black ground color distinctly visible in most angles. Third 

 segment much more densly poUinose with deeper yellow. A median 

 narrow black stripe usually and an apical black or reddish shining 

 band always visible; fourth segment entirely yellow pollinose with 

 scattered black hairs in addition to the usual apical bristles. First 

 and second segments with a single pair of median marginals, third 

 with a row of about 12. Genitalia small, the outer forceps somewhat 

 longer than the inner and decidedly sharp at apex. 



Legs black, pulvilli elongated, the front ones almost equal to the 

 last two tarsal joints. Hind tibia with a row of unusually erect 

 bristles on the outer side. 



Wings considerable brownish at base, less so apically. Calypters 

 whitish, the anterior with a slight yellow tinge, both with yellow rim. 



Female. — Front at vertex 0.35-0.37 of the head width. Three pairs 

 of proclinate bristles, antennae more slender, third joint less than 

 double the second. Facial ridges with only three or four bristles. 



Length, 9-10 mm. 



Redescribed from the type lot, consisting of five males and two 

 females collected at Piura, Peru, August 28 and September 4 and 8, 

 1910 (C. H. T. Townsend) ; the museum also has two additional males 

 from Peru (Townsend), and Professor Hine has sent a female which 

 he collected March 18, 1905, at Panzos, Guatemala. Insularis was 

 described from a single female from Barrios, P. R., which I had pre- 

 viously compared with this type series and with some doubt pronounced 

 identical. 



r2/l>e.— Female, Cat. No. 15191, U.S.N.M. 



