SYNOPSIS OF NORTH AMERICAN SYRPHIDJE. 65 



iu the male, contignons in this sex. Front a little couvex ; frontal 

 triangle large. Aiiteunai short, third joint large oval. Face slightly 

 concave below the antennie, obtusely tuberculate. Scutellum much 

 raised, exposing the metanotum. Abdomen elliptical iu the female, the 

 fifth segment about half as long as the preceding^ * iu the male the sixth 

 abdominal segmeut as long as the two preceding segments taken to- 

 gether, but narrower, couvex, almost tubular when seen from above, 

 unsymmetrical, the end pointing slightly to the right; the seventh seg- 

 ment bears the anal opening on the under side of the sixth ; beyond 

 the anus there are two long slender subparallel appeudages, arcuate, 

 bidenticulate at the end, nearly as long as the sixth segment, bent un- 

 der the body when at rest, and embedded iu a horny groove on the under 

 side of the sixth segment, which encroaches on the fifth. Legs simjile. 

 Marginal cell of the wing open ; small cross- vein near the base of discal 

 cell, rectangular; third longitudinal vein gently curved. Type of genus, 

 U. volucris O. S. 



Eupeodes volucris. (Flute, III figs. 14, 14a.) 



Eupeodes volucris Osteu Sacken, West. Dipt., 329. 

 Syrphus perpallidus Bigot, Annales Soc. Ent. Fr., 1884,90. 



Eabitat. — Washington Territory, California, Nevada, Utah, Kansas, 

 Colorado, New Mexico, Arizona ! 



0,9. Length, 7 to 10™™. Eyes bare. Face whitish yellow, with black 

 cheeks and a brown or black stripe over the facial tubercle. Frontal 

 triangle whitish yellow with some black pile ; front in female black, 

 across the middle a faint subinterrupted arcuate band of whitish 

 pollen leaving a triangular shining space below, lower part of the front 

 yellow, except a dark brown crescent-shaped spot above the root of the 

 antennae. Antennae brown or black. Thorax dark metallic green, some- 

 times slightly bluish, with very pale yellowish pile. Scutellum in male 

 yellowish, more or less translucent metallescent, with pale yellow pile; 

 scutellum in female distinctly yellow along the edge. Abdomen black, 

 subopaque ; the first segmeut, the lateral and i)Osterior margins of all 

 the segments, shining, the fifth wholly shining ; on the second segment 

 two yellow oblong spots, well separated from the lateral margin ; on 

 each of the two following segments a pair of longer, oblong yellow 

 spots ; those on segments three and four very slightly lunate ; the pos- 

 terior margins of the fourth and fifth segments narrowly yellow; sixth 

 segment shining black, sparsely beset with whitish pile. Legs reddish ; 

 base of femora black, a little less extensive in the female; hind femora 

 black, except the tip ; hind tarsi more or less brown on the upper side. 

 Wings hyaline; stigma yellowish brown. 



Fifty specimens. The most common Syrphid on the plains in sum- 

 mer. 



* The female of Syrphus diversipes has the fifth abdominal segment longer than 

 in the other species of the genus. 



