PROC. EXT. SOC. WASH., VOL. 21, XO. 6, JUNE, IQIQ l-< 



i 



one presutrual, one supraalar, one postalar; no mesopleural, or pteropleural 

 bristles, one sternopleural, a row of bristles on the sternopleura near the 

 middle coxa; hind coxa with one large bristle on the outside. Scutellum with 

 two large, marginal pairs of bristles. Wing normal, sixth vein to the wing 

 margin; two small, basal cells. 



Type Ambopogon hyperboreus, n. sp. 



Cochliarutm (Becker, Dipterologische Studien I, Berliner 

 Entomol. Ztg. Bd. XXXIX, 1894, p. 183, Heft i) is the nearest 

 relative, although quite remote and very distinct. 



A . hyperboreus, n. sp. Male (Fig. i). -Brownish black, legs mostly yellow. 



From in front the head is slightly wider than high. Face very small and 

 pale yellow, darker on the sides; antennae missing, antennal pits located about 

 the lower fifth of the eye; front narrowing towards the antennae, yellow, a 

 brownish area across the lunule, a broad V-shape depression in the middle with 

 the upper ends more golden; vertex, ocellar triangle and upper part of the 

 face along the orbits dark brown and shining; numerous dark, bristly hairs 

 on apical half of front; eyes cover nearly half the side of the head; occiput 

 well developed, nearly as wide as the horizontal diameter of the eye, upper 

 half of occiput black with numerous black hairs which extend down on the 

 yellow of the lower half; a group of closely set brownish, bristly hairs on the 

 occiput close to the junction of the neck; lower edge of head nearly straight, 

 a broad ridge starting at the front and extending half way along the lower 

 edge of the head. On this ridge are the whiskers, which are extremely long, 

 curved backward, blackish bristles, very pale toward the apex, back of these 

 bristles the beard is more like bristly hairs; on the front end of this ridge 

 are located several bristles which are directed slightly forward; no distinct 

 oral vibrissae in the male; back of this heavy beard, along the oral opening, 

 are very numerous whitish hairs which are curly or crinkly at the apex. 

 These bristly hairs are more numerous towards the front. 



Thorax shiny and nearly black with numerous short black hairs; on the 

 dorsum is a broad stripe from the apex to the scutellum and a narrow area 

 above the pleural suture, from humeral callus to the wing, white, pruinose; 

 scutellum very faintly white pruinose; halteres white, brownish at base. 

 Abdomen nearly black with numerous black hairs; first segment quite long, 

 sides parallel, second and third segments much shorter than the first, but 

 both widen considerably toward their apices; fourth segment nearly twice 

 the length of the third and narrowing slightly at the apex; next segment 

 globular, chitinous, and with a tuft of bristly hairs in the middle and at the 

 apex; last segment globular with a heavy brush of large, dark brown bristles 

 which are yellowish and crinkly at the apex. These bristles are about three 

 times the length of the segment. Forceps reddish brown, points widely- 

 separated. Venter has numerous, long, yellowish hairs on second and third 

 segments. Near the apical corner of the lirst and second segments, on the 



