ATtT. 16. NORTH AMERICAN SCELLUS GREENE. 7 



black, though the root and the margin of half the costa is whitish, 

 the Avhole posterior margin gray ; anal appendages of the male white, 

 toward the basis on the under side with a black margin, toward the 

 tip yellow^, at the extreme tip marked with a brown spot. Long, 

 corp. 0.15. Long. al. 0.19. 



'-'■Male. — ^Blackish bronze-colored. The face is comparatively a 

 little broader than in S. exustus, covered with bright ocher-yellow 

 dust and opaque. Antennae black. Front with whitish dust. The 

 ground color of the thorax is of a coppery-bronze ; upon the middle of 

 the upper side more of a blackish-bronze, but almost everywhere so 

 thickly covered with dust that the coppery luster is only very little 

 perceptible ; the dust on the upper side of the thorax is snow-white, 

 upon the two longitudinal stripes near the lateral margin it is less 

 thick, so that the coppery reflection of the ground-color is more dis- 

 tinct; upon the middle there are two narrow, dark longitudinal lines, 

 close to each other, which do not reach as far as the posterior margin 

 of the thorax. Upon the pleurae the color of the dust is more yel- 

 lowish. The scutellum has two bristles, is rather opaque, with a thin 

 whitish dust. Abdomen green, mostly with a coppery luster, which 

 becomes much more bright near the lateral margin. The anal ap- 

 pendages are of middling length, white, near the basis of the lower 

 margin with a narrow black border, and on the upper margin usually 

 marked with a black spot; beyond the middle they are inflected up- 

 ward and gradually assume a yellow color; their extreme tip is 

 marked with a small brown spot and bears a small tuft of delicate 

 pale hairs, which are turned backward; about the middle of the 

 interior margin there is a similar pubescence ; between them, toward 

 the anal region, there is a small tuft of delicate whitish hairs. Coxae 

 bronze-black; the four anterior with yellow and the two hind ones 

 with a rather whitish dust ; the fore coxae with very short and deli- 

 cate pale hairs, near and upon the tip with a few black bristles. Feet 

 black, femora and tibiae more black-green, the former bright cop- 

 pery. Fore femora short, toward the basis very much thickened, 

 beset on the under side with bristles of different length, on the front 

 side with a row of stiff black bristles. Middle femora long, stronger 

 than in S. exustus and more curved, on the latter half of the under 

 side with erect black bristles. Hind femora of a plain structure, not 

 stouter than the middle femora; their under side has only, close be- 

 fore the tip, a few black bristles. The comparatively stout fore 

 tibiae have on their front side, not far from their basis, a stout black 

 thorn ; their tip is elongated into a very stout tooth, before which the 

 under side of the tibiae, which is beset with strong bristles, has a 

 small excision. Middle tibiae not quite so long and slender as those 

 of S. exustus, on the upper side only with three or four short bris- 

 tles, on the under side with a row of extremely long, straight, erect 



