DESCRIPTIONS OF ALASKAN DIPTERA OF THE 

 FAMILY SYRPHID^. 



JAMES S. HINE 

 Department of Zoology and Entomology, Ohio State University 



All of the species treated in this paper except Sericomia 

 cynoctphala were collected by the Katmai Expeditions of the 

 National Geographic Society. Full accounts of the insect 

 collections of these expeditions are being prepared for pubhcation, 

 but as it is desired to refer to some of the species in other papers 

 these descriptions are published in advance of the final report. 



Chilosia platycera n. sp. 



Male and female shining black. General form of the body elongate 

 and rather slender. Vestiture of the body mostly pale, scutellum with 

 a marginal row of slender black bristles, eyes naked, antennse yellow, 

 aristce dark, naked; legs largely black, apex of each femur yellow, 

 tibiffl and tarsi partially yellow; wings pale yellowish hyaline. Length 

 5-7 mm. 



Female: Eyes bare, face and front shining black, front largely pale 

 pilose, but with a few black hairs intermixed, face below the antennae 

 concave, facial tubercle rather prominent, much nearer the mouth than 

 to the base of the antennae. Antenna wholly yellow, arista dark, nearly 

 black, bare, third segment unusually large, only slightly longer than 

 wide. Thorax wholly shining black with short, pale, pile rather sparsely 

 distributed. Scutellum with a few slender marginal bristles. Wings 

 pale yellowish hyaline, halteres and squamae pale, nearly white; legs in 

 large part black, narrow apex of each femur, base and apex of each tibia 

 and second, third and fourth tarsal segments on all the feet yellow. 

 Abdomen shining black all over, pilosity short and pale grayish in color. 



Male: Colored like the female, frontal triangle with long black pile, 

 antennae yellow, third segment decidedly smaller than in the female, 

 pilosity of the body rather long and conspicuous, especially along the 

 side margins of the abdomen, abdomen entirely shining, slenderer than 

 in the other sex. 



Female type, Katmai, Alaska, July, 1917. Allotype with 

 the same data. Paratypes, 12 females and 3 males from the 

 same locahty taken in June and July, 1917, and one female 

 from Savanosky, Naknek Lake, Alaska, July, 1919. Type in 

 the Ohio State University Collection. 



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