36 KANSAS UNIVERSITY QUARTERLY. 



of the abdomen with silvery white pile, longest and thickest at the 

 base ; the blue marking are whitish pruinose. Femora, except the 

 tip, a broad ring on the tibiae, and the four posterior tarsi, black ; else- 

 where brownish or yellowish. Wings hyaline, stigma yellowish. 



Length 7-8 millimeters. 

 Eupeodes volucris, Osten Sacken. 



Numerous specimens, Colorado. 

 Syrphus arcuatus Fallen. 



Four specimens, Colorado. These specimens vary not a little from 

 each other, and somewhat from the descriptions. One female is very 

 small, not over seven millimeters in length, and with the spots on the 

 third and fourth abdominal segments hardly oblique. One male has 

 the hind femora black as far as the tip, while in three females the 

 black does not extend beyond the middle. 



Syrphus disjectus Williston. 



A single female specimen, from Colorado, agrees well with the de- 

 scription drawn from males. The pile of the thorax is more whitish 

 than orange-yellow, and there are light colored lateral margins on the 

 anterior part of the thorax. 



Syrphus ruflcauda, n. sp., Plate vii, t 3. 



Male. Eyes bare. Face greenish yellow on the sides, yellow in the 

 middle; a rather broad black line marks the border of the mouth and 

 is lost in the black of the cheeks. Frontal triangle yellow, with long 

 black pile. Antennae dark brown, more or less reddish below. Pile 

 of occiput light yellow. Dorsum of thorax deep metallic green, the 

 scutellum olivaceous yellow; both with light yellow pile. First seg- 

 ment of the abdomen shining black ; second segment opaque black, 

 with the lateral margins and hind border shining, and with a broad, 

 yellow, interrupted band, not reaching the lateral margins ; third seg- 

 ment similar, but with the yellow band somewhat wider, interrupted 

 or subinterrupted and slightly bilaterally oblique ; fourth and fifth 

 segments orange-red, the sides narrowly black ; the fourth segment 

 shows indistinctly a broad interrupted band of a somewhat lighter 

 color, corresponding to the yellow bands of the preceding segments. 

 Legs light brown ; basal third of the front and middle femora and 

 basal half of the hind femora black. Wings hyaline, stigma yellowish. 



Female. Head wanting. Thorax purplish brown. The yellow 

 band on the second abdominal segment narrower, the second band 

 straight, narrower and interrupted. Legs light brown, except the 

 proximal end of the femora, which is black. 



Length 9 millimeters. Three males and one female, Colorado. 



