OSTEN SACKEN ON WESTERN DIPTERA. 251 



6. BojVIBYLTTJS LANCIFER E. sp., $ 9. — Body black, densely clotbecl 

 with yellow fnr; tufts of brown pile in the i)osteiior corners of the tho- 

 rax, and. two tufts of black pile on each side of the abdomen connected 

 by rows of black pile over the back ; a stripe of dark brown pile between 

 the humerus and the root of the wing; ou the chest, the hair is paler; 

 on the mentum, white. Epistoma yellowish-brown, shining above, 

 grayish-pollinose on the sides, beset with black pile ; frontal triangle in 

 the male grayish-pollinose, beset with black pile; the whole front and 

 vertex in the female grayish-pollinose, beset with some recumbent 

 golden-yellow tomentum and longer black pile. Proboscis long, as 

 long as the body, perhaps a little longer. Third joint of the anteunte 

 moderately broad, with parallel sides, on its last third tapering toward 

 the tip. Legs red, thinly clothed with whitish scales, and beset with 

 black spines; tarsi brown, reddish at base; knees dark brown, espe- 

 cially ou their anterior side. Wings blackish-brown on their basal 

 half; strongly tinged with grayish on the rest of the surface. Length 



Hah. — San Francisco, Cal. (H. Edwards); Yosemite Valley (June 9). 

 One male and two females. The fur is intact in the male only; that of the 

 female, which I took in Yosemite Valley, is more whitish. In general 

 appearance, B. lancifer is not nnlike B. varius of the Atlantic States ; 

 but the latter has a much shorter proboscis, a distinctly lanceolate third 

 autennal joint, black pile on the chest, wings less grayish on their distal 

 portion, etc. 



Anastcechus nov. gen. 



Closely allied to SystceGlius, but easily distinguished from the xSTorth 

 American species of that genus by the following characters: — 



Head comparatively larger, and front of the female broader. 



Face, cheeks, and loicer part of the front are beset with erect pile, 

 which forms a dense broad brush, entirely concealing from view the 

 outlines of the mouth and cheeks, as well as the basal joints of the 

 antennae. When the pile is removed, the face shows a structure en- 

 tirely ditiereut from that of Systoechus ; in the profile, the mouth, instead) 

 of projecting forward, has its sides, the cheeks, on the same plane with 

 tbe eyes, and even somewhat withdrawn behind them; the epistoma^ 

 or face above the mouth, projects very little, and descends almost directly 

 below the antennae. 



Byes, in the male, separated by an interval ou the vertex, which is 

 not coarctate in front of the ocelli; a distinct oblique line separates the 

 upper and larger facets from tbe lower and smaller ones (in Systwchus^ 

 the narrow interval between the eyes on the vertex is strongly coarctate 

 in front of the ocelli; the passage between the two kinds of facets is 

 gradual and imperceptible); in the female, the interval between the 

 eyes is about one-half broader than the horizontal diameter of the eye.. 



Antemice of the same structure as in Systcechus, but the third joint, 

 beyond the usual ring-like expansion at the extreme base, is, for a cer- 

 5 H B 



