170 DIPTERA OF NORTH AMERICA. [PART III, 



genera, which likewise have the third anteimal joint with a sharp 

 anterior angle, the species of the present genus are sufficiently 

 distinguished by their less slender shape and the different 

 structure of the anal cell, not to mention other characters. 



1. C. aenea Wied. % 9.— (Tab. IX, f. 19.) Viridis. antennis fusco- 

 nigris, basi tamen articuli tertii lutea, alis trifasciatis. 



Metallic-green ; antennae brownish-black, the basis of the third joint yel- 

 low ; wings with three bands. Long. corp. 0.16 — 0.18; long. al. 0.17 

 —0.18. 



Syn. Ortalis cenea Wied. Auss. Zweifl. II, p. 462, 8. 



Ortalis trifasciata Say, Journ. Acad. Phil. VI, p. 184, 3. 

 Urophora fulvifrons Macq. Dipt. Exot. Suppl. V, p. 125, Tab. VI, f. 9. 

 Chcetopsis cenea Loew, Berl. Ent. Zeitschr. XI, p. 315, Tab. II, f. 21. 

 Trypeta (Aciura) cenea v. d. Wulp, Tijdsohr. voor Ent. 1867, p. 137, 

 Tab. V, f. 12—14. 



Front red, on each side with a broad band, which is covered 

 with white pollen. The ocelli rather far distant from the edge 

 of the vertex; the region of the ocelli, as well as the little stripes 

 descending from the vertex along the orbits of the eyes are 

 blackish-green, only very little shining. Frontal lunule with 

 white pollen. Antennae rather short; the first two joints brown, 

 the second sometimes in part brownish-yellow; the third joint 

 rather broad, very little excised on the upper side, always with 

 a sharp anterior angle, brownish-black, reddish-yellow at the 

 basis. Face only little excavated, steel-bluish, but rather opaque 

 on account of a whitish pollen ; the edge of the mouth usually 

 brick-red. The clypeus has but a small transverse diameter and 

 is but little projecting over the anterior edge of the mouth. 

 Thorax and scutellum shining metallic-green, upon the dorsum 

 with a trace of a white bloom. Abdomen of the same color, or 

 somewhat more bronze-green, the last joints of the male abdomen 

 generally blackish-green. With less mature individuals the 

 coloring of thorax and abdomen is more bluish-green, and at the 

 basis of the latter an unmetallic, dirty-yellow coloring may be 

 seen. The coloring of the feet is variable ; in some specimens 

 they are altogether pale-yellow, only a little darker at the tip of 

 the tarsi ; as this occurs in those specimens which have the basis 

 of the abdomen yellow, one might almost be led to the conclusion 

 that they form a distinct species; however, the absolute similarity 

 of all the other characters renders this conclusion very improba- 



