256 DIPTERA OF NORTH AMERICA. [PART II. 



upon the outside. Halteres with blackish peduncle and yellow 

 knob. 



Hub. Mexico. 



Observation 1. — This species varies somewhat in the extension 

 of the bands on the wings, still they are never as broad as in P. 

 jiatibulatus, but sometimes interrupted between the third and 

 fourth longitudinal veins. 



Observation 2. — I was in possession of the 9 of this species a 

 long time ago, but although convinced of its specific distinctness 

 (vid. Neue Beitr., YIII, 8G), I would not describe it without the 

 male. It is easily distinguished in both sexes from P. patibulatus, 

 with which, among the species known to me, it has the closest re- 

 semblance, by its glabrous face, and besides, in the male, by the 

 different structure of the fore tarsi. I presume that Say has con- 

 founded this Mexican species with his P. 'patibulatus, of which he 

 says he has seen Mexican specimens. 



6. P. piloSUS Loew. %. — Ex chalybeo viridis, nitidus, abdomine 

 fasciis aequalibus nigris ornato, alarum fasciis duabus nigricantibus, 

 antice conjunctis et postice abbreviates, facie nuda (?), pedibus nigris, 

 tibiis anticis tarsorumque interniediorum articulo prinio testaceis, hoc et 

 tibiis interirjediis in latere superiore breviter ciliatis. 



Bluish-green, shining, abdomen with equal, broad, black bands ; the two 

 blackish bands of the wings connected in front, shortened behind ; face 

 without hairs (?) ; feet black, the fore tibiae and the first joint of the 

 middle tarsi brownish-yellow ; the latter and the middle tibia? upon the 

 upper side, provided wfth short cilia. Long. corp. 0.24. Long. al. 0.25 

 —0.26. 



Syn. Psilopus pilosus Loew, Neue Beitr., VIII, 86, 4. 



Bright green, the head, the hind part of the thorax, the scutel- 

 lum, as also the basis and the tip of the abdomen, in the described 

 specimen, more steel-blue and bright shining. Palpi black ; pro- 

 boscis brownish-yellow. Face rather closely dusted with white, 

 in the described specimen without all pubescence, which however 

 may have been rubbed off. Second joint of the antennae upon the 

 under side with rather long, upon the upper side with shorter 

 bristles, these curved forward; third joint small, rounded; arista 

 distinctly dorsal, of medium length. Front with a black pubescence 

 in the upper corner near the eye. Thorax and scutelluin with 

 rather long black bristles. Pleurae black with a green reflection, 



