PLAGIONEURUS. 197 



Face not very broad for a female, somewhat elevated, upon its 

 larger upper part with an impressed middle line ; the smaller, con- 

 vex lower part is separated from the upper part by a transverse 

 swelling, incomplete in its middle ; the dense, almost silvery-white 

 dust, conceals a great deal of the ground-color of the face. An- 

 tennae black. The third joint with a short, but sharp tip ; the 

 arista rather strong, with a very short but distinct pubescence. 

 Front bright metallic blue-green. The cilia on the upper orbit 

 black, on the entire lateral and lower orbits white. Thorax me-, 

 tallic-greeu, only on the fore and lateral margin with a little 

 whitish dust, upon the middle with a not very sharply defined 

 longitudinal stripe, which in some directions appears more black, 

 in others more brown and purple, sometimes of a beautiful cinna- 

 mon-brown color. Scutellum metallic-green, with the usual two 

 strong bristles, otherwise bare. On the segments of the abdomen 

 the two first thirds have a dark, the last third a more pale color ; 

 the color of the former part shifts from black, through bronze- 

 brown into a beautiful dark violet ; on the last third the color is 

 chiefly metallic-green, nevertheless it changes on the anterior part 

 into steel-blue, and on the hind margin of the segment into golden- 

 green or- almost a coppery color ; on' the lateral margin the last 

 third of the segments is covered with white dust. Coxa3 black 

 with a rather dusky-green lustre ; the foremost with white dust, 

 clothed with delicate white little hairs, and at the tip with a few 

 black bristles. Feet black ; femora with green lustre ; knees 

 brownish-yellow ; this coloring extends on_the fore tibice as far as 

 the middle, on the middle tibiae as far as the first third, while on 

 the hind feet it is confined to the tip of the knee. The femora 

 have on the under side from the basis almost as far as the tip, 

 erect, but short, whitish hairs ; otherwise their hair is black ; mid- 

 dle and hind femora have on the front side before the tip a few 

 insignificant black bristles. The hair upon the tibiae is altogether 

 black, very short, only on the upper side of the hind tibiae some- 

 what longer, so that its great density is easily perceived ; all the 

 tibiae are beset with short and not very numerous black bristles. 

 Wings tinged with smoky gray, the veins brown-black ; the pos- 

 terior transverse- vein is so very much oblique as to run parallel 

 to the hind margin of the wing ; the last segment of the fourth 

 longitudinal vein approaches the margin of the wing rather closely, 

 without changing its course, then, however, it suddenly turns 



