[427] DIPTERA 41 



face only slightly produced downward; first two joints of antennas 

 black, the thii'd dark brown, orbicular, as wide as long, the arista 

 black, almost bare ; eyes densely covered with rather long yellowish 

 or black hairs ; body greenish black, polished, the hairs mixed yellow 

 and black, on front part of mesonotum and sides of abdomen chiefly 

 yellow, scutellum bearing several marginal black, bristly hairs, second 

 and third segments of abdomen, except the sides and front angles, 

 of a purer black color, venter polished, its hairs yellow ; legs black, 

 extreme apices of the femora, broad bases and narrower apices of the 

 tibiae yellow ; halteres yellow, center of the knobs brown; wings grayish 

 hyaline, sometimes tinged with yellow on the costo-basal half, the 

 veins brown, stigma pale yellowish. 



Female : Differs from the male as follows : Hairs of front and of 

 body almost wholly yellow, front not sulcate, abdomen destitute of 

 purer black portions, halteres wholly light yellow. Length 5 to 7 mm. 

 Four males and seventeen females. 



Habitat. Yakutat, June 21; Virgin Bay, June 25 ; Kukak Bay, 

 July i and 4; Kadiak, July 20; Saldovia, Alaska, July 21. 



Type. Cat. no. 5237, U. S. National Museum. 



Closely related to occidentalism but in that species the sides of the 

 median portion of the face are hairy, and the size is much larger. 



Chilosia alaskensis Hunter. 



Chilosia alaskensis HUNTER, Canadian Entom., p. 124, 1897. 



Yakutat, Alaska : A single specimen, collected June 21. Originally 

 described from Alaska. 



Chilosia lasiophthalma Wil listen. 



Chilosia lasiophthalma WILLISTON, Proc. Am. Phil. Soc., p. 306, 1882. 

 Synopsis N. Am. Syrphidae, p. 40, 1886. 



Yakutat, June 21 ; Kukak Bay, Alaska, July i : Five specimens. 

 Originally described from Colorado. 



Chilosia tristis Loew. 



Chilosia tristis LOEW, Berliner Entom. Zeitsch., p. 312, 1863. 



Saldovia, Alaska, July 21 : Three specimens. Originally described 

 from the Red River, British America. 



Chilosia plutonia Hunter. 



Chilosia plutonia HUNTER, Canadian Ent., p. 125, 1897. 

 Chilosia gracilis HUNTER, loc. cit., p. 126. 



Sitka, June 16; Yakutat, June 21 ; Virgin Bay, June 26; Kukak 

 Bay, July i and 4; Popof Island, July 8 to 15; Kadiak, July 20; 



