APHCEBANTUS. * 149 



Face with a silvery pubescence ; front pollinose yellowish-grey, with short, erect, black hair ; antennae 

 black ; the third joint triangular, onion-shaped, the style but slightly longer than the incrassate base. 

 Length 5 millim. 



Hob. Mexico, Northern Sonora (Morrison). A single female. 



This species bears a singular resemblance to Epacmus modestus, from which, however, 

 it is generically distinct ; the latter has a somewhat similar bisected scutellum, and its 

 abdomen is clothed in nearly the same way with alternately ochreous and white scale- 

 like hairs. The bisection of the scutellum does not seem to be a constant character of 

 E. modestus ; it remains to be seen whether this also applies to A. bisulcus. 



8. Aphcehantus carbonarius, sp. n., s $ . 



Face greyish-black, with a pubescence that, in an oblique light, looks silvery : front hoary above the antennae, with 

 a black pubescence, mixed with a few pale yellowish hairs : the third joint of the antennae very short-conical 

 or onion-shaped, unsymmetrical, prolonged in a style wbich is more than twice as long as the joint itself, 

 with the usual minute joint and bristle at the tip. Thorax black, thinly beset with yellowish semiappressed 

 hairs on the dorsum, and with longer and denser white hairs on the pleurae. Abdomen deep black, with 

 fringes of scale-like yellowish -white hairs on the hind margins of the segments, the fringe on the first 

 segment the broadest, the black intervals between the fringes covered with scattered deep black scales 

 resembling soot; the sides showing scattered whitish-yellow scales, the venter more dense silvery 

 ones especially at the base ; a fan-like tuft of longer, pale yellowish- white hairs on each side at 

 the base ; in the male a fringe of long, delicate whitish hairs along the sides. Halteres yellow. A 

 number of rather weak macrochaetae on the scutellum and on the prae- and post-alar callosities (in my 

 specimens they are brownish-red or reddish-yellow). Femora black, beset with silvery scales ; knees, 

 tibiae, and tarsi reddish-yellow ; the latter brownish towards the tip (one of my specimens has the tibiae 

 and tarsi dark brown, nearly black) ; tibiae beset with silvery scales and with delicate spinules. Male 

 forceps projecting, although only slightly club-shaped ; its two halves enclosed within the concavity of the 

 last ventral segment, which, from a side view, is not projected downwards. Wings hyaline, without stamps 

 on the third vein. 



Length 6-8 millim. 



Hab. North America, Washington Territory and Western Kansas (Williston). — 



Mexico, Northern Sonora (Morrison). One male, three females. 



This species seems to be allied to A. (Triodites) mus, on account of its general 

 appearance, and of the deep black, soot-like scales on its abdomen. It is, however, usually 

 smaller, the tibige and tarsi are more reddish, the knob of the halteres yellow and not 

 brownish, and the thorax of a purer black (not greyish) and less downy ; the margins of 

 the abdominal segments of a less pure white. The male sex is easy to distinguish by 

 the structure of its forceps: small and concealed within the abdomen in A mus, 

 larger and projecting in A. carbonarius ; in the former the posterior segments of the 

 abdomen have but indistinct white margins ; on the contrary, in the latter they are 

 equally distinct in both sexes. 



9. Aphcebantus peodes, sp. n., 6 $ . 



Face black, with short, erect, black hairs (I perceive some traces of white pollen on the upper part only) ; front 

 in the male with a strong silvery reflection and with the hair upon it principally whitish (apparently the 



