CIIRYSOTUS. 177 



covered with brown-gray clust ; the very small palpi black. The* 

 third joint of the antennae comparatively with long hair, rather 

 large, oblique, its upper margin much more arched than the lower 

 margin, which is almost straight ; the arista is subapical. Front 

 metallic-green, without a distinct trace of dust, and becoming 

 broader upwards. Thorax shining green, sometimes rather gold- 

 green. Coxae and femora black with metallic-green lustre ; on the 

 four anterior feet the extreme tip of the femora, the tibiae and 

 the greater part of the first joint of the tarsi are yellow, the fol- 

 lowing part of the tarsi black-brown; the hind tibiae and hind 

 tarsi are decidedly of a brown-black color. The hair upon the 

 feet, though somewhat rough, is short, and even on the hind tibiae 

 of very moderate length ; the hind femora have on the under side 

 before the tip but a few bristle-like hairs ; the bristles on the tibiae 

 arc very scarce ; the pulvilli are very small even on the fore tarsi. 

 Cilia of the tegulae black, though some of them exhibit in a re- 

 flected light a yellow-brownish glitter. Wings somewhat tinged 

 with gray ; veins black ; the posterior transverse vein very close 

 to the root of the wing ; the last segment of the fourth longitu- 

 dinal vein parallel to the third and ending a little before the tip 

 of the wing. 



Female. Face of moderate breadth with grayish- white dust 

 upon rather black ground ; the usual transverse swelling is far 

 below its middle. Palpi blackish, the third joint of the antennae 

 smaller than that of males, and its oblique form less striking. 

 The brownish-yellow dust on the upper side of the thorax some- 

 what more dense than in males. The color of the four anterior 

 \ feet like that of the males ; the hind tibiae yellow with a somewhat 

 dusky tip ; hind tarsi dark brown, the first joint is sometimes more 

 yellowish-brown near the basis. Wings like those of the male, 

 only the anal angle somewhat more protruding. 



Hab. New York. (Osten-Sacken.) 



Observation. — I have no ground for doubting that these two 

 sexes belong together, as all those characters which distinguish 

 the male from the female are within the range of the sexual dis- 

 tinctions peculiar to this genus, and the agreement of all the other 

 characters is very striking. 



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