2-20 DIPTERA OF NORTH AMERICA. [PART II. 



striking. The upper part of the pleurae is covered with gray dust 

 and the bristles above the fore coxae are of a pale color. The 

 abdomen is less thickly dusted than the thorax, appears however 

 rather gray in some directions on account of its cover of dust. 

 The peduncle of the hypopygium is so short as to appear ses- 

 sile ; it is rather stout, ovate, almost reversed-pyriform, black, 

 polished on its entire right side and on the latter half of the left 

 side. Coxae black. Feet brownish-yellow, all femora, from the 

 root as far as the middle, pitch-black, this color vanishing gradu- 

 ally. Cilia of the tegula whitish ; halteres whitish with a darker 

 peduncle. Wings hyaline, scarcely tinged with a little gray, 

 veins brownish ; the posterior transverse vein distant from the 

 margin of the wing more than its own length. The third longi- 

 tudinal vein ends a little farther from the tip of the wing than 

 in the preceding species ; the last segment of the fourth longi- 

 tudinal vein is also very straight, converges, however, less towards 

 the third longitudinal vein than in M. nigripes. 



Hab. Florida. (Osten-Sacken.) 



Observation. I have received from Mr. Le Baron two females,, 

 captured in Illinois. They are somewhat larger than the above 

 described male, and the lower part of the face is greenish-blue, but , 

 very little shining. Otherwise they agree with it perfectly. The - 

 different color of the lower part of the face would be a sufficieir 

 specific distinction, if the bad condition of the above describee 

 male of M. veles did not admit the supposition that the differenc , 

 in its color is an unnatural one. I prefer therefore not to conside 

 these females as belonging to a different species. 



Gen. XL. CHRYSOTIMUS. 



Characters. Size of the body small. Antennas small ; thar 

 first joint glabrous ; the third joint very short, usually broader 

 than long, distinctly hairy, with an apical or almost apical ariste. 

 Eyes with a very short pubescence. The posterior end of taej 

 thorax with a rather large, distinctly concave, sloping ara.. 

 The bristles upon thorax and scutellum yellow. Abdomen in alii 

 the species partially yellow. Feet not elongated ; the first joint 

 of the hind tarsi without bristles. Posterior transverse vein upj>n,, 

 or more or less before, the middle of the wing ; the last segment 

 of the fourth longitudinal vein neither broken nor distinctly .Ijent 



