psilopus. 247 



Head purplish-blue ; the frout has, besides the ordinary black 

 bristles, no pubescence ; the naked face is rather densely covered 

 with whitish dust. The small antennae are black ; their second 

 joint is beset with only a few short bristles ; the arista is of 

 medium size only and has a dorsal position. Proboscis, brownish- 

 yellow ; palpi, blackish-brown. The coloring of the thorax is 

 purplish-blue, shining, but changes upon its posterior half into 

 steel-blue, and before the scutellum even into a bluish-green. 

 Scutellum greenish-blue. Pleurae black with a greenish reflec- 

 tion, dusted with white. Abdomen metallic-green, shining ; the 

 bristles of the single segments before the hind margin are but of 

 medium length. The hypopygium is small ; the form and color- 

 ing of its appendages cannot be distinguished with certainty in 

 the described specimen, still the size of the appendages seems to 

 be but small. Coxae brownish-black, dusted with white, the fore- 

 most with minute whitish hairs and bristles. The slender, rather 

 glabrous femora are brownish-black, but at the extreme tip, yel- 

 low ; the yellow tibiae are slender, beset with very short black 

 hairs, which are somewhat more erect on the middle tibiae. Tarsi 

 plain, slender, brown, somewhat more brownish-yellow towards 

 the basis ; the four anterior ones are much longer than the tibiae, 

 and their first joint much longer than the four following joints 

 taken together ; the hind ones are hardly of the same length with 

 the tibiae, but their first joint is likewise perceptibly longer than 

 the four following joints taken together. Tegulae bordered and 

 ciliated with black. Wings brownish-black, the last third, the 

 hind margin, and the greatest part of the anal angle grayish- 

 hyaline ; the fore margin of the wing is fringed, almost ciliated 

 with comparatively long, minute hairs ; the hind transverse vein 

 has a very oblique position. 



Hab. Mexico. (Collect. Winthem.) 



b. Wings hyaline with two black bands connected on the anterior margin. 



2. P. siplio Say. % and <? . — Chalybeus vel viridis, rarius aureo- 

 viridis, nitidissimus, alarum fasciis duabus nigricantibus, antice con- 

 junct s et postice abbreviatis, facie nuda, pedibus in ntroque sexu flavis, 

 maris metatarsis intermediis non ciliatis. 



Steel-blue or green, seldom golden-green, very shining ; wings with two 

 blackish bands, connected in front and abbreviated behind ; face with- 

 out hairs ; feet yellow in both sexes ; the first joint of the middle tarsi of 

 the % not ciliated. Long. corp. 0.21—0.24. Long. al. 0.22—0.24. 



