64 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



Scceva pijrastri Fabricius, Autl., 249, 3; Fallen, Syrpb., 39, 5; Zetterstedt, Dipt. 



Scand., ii, 703, and viii, 3132. 

 Scceva transjuga Fabricins, Antl.,250, 5. 

 ScoRva affinis Say, J. Acad. Phil., iii,99, 9; Compl., ii,8I. 

 Sy7-phu9 affinis Wiedemann, Auss. Zw. Ins., ii, 117,2. 

 Lasiophlicus j)yrastri Rondani, Ann. d. Acad. d. Aspir. Nat., iii. 

 Catabemba piirastri Osteu Sacken, Western Dipt., 325. 



Habitat. — Kansas, Colorado, Wyoming, Washington Territory, Or- 

 egon, Utah, Arizona !, Scandinavia (Zett.), England (Walk.), Germany 

 (Schiner), France, Algiers. (]hili (Macq.), Italy (Rond.), Canary Islands 

 (Webb and Berthelot). 



6,9. Length, 11 to 12'""". Face light yellow, somewhat bluish opal- 

 escent, often in dried specimens with a reddish tinge, a brown spot on 

 the tubercle extending more broadlj" to the oral margin ; pile abundant, 

 whitish. Cheeks greenish black. Antenna? brownish black, often red. 

 on the under side of the lirst, second, and the third joint near the base; 

 arista red. Front yellow, with a slender line reaching from the antennae 

 to the vei'tex or commissure, on each side of which the front is broadly 

 subtranslucent olivaceous, the vertex black ; pile black, in the male 

 longer and more abundant. Eyes of male contiguous for about half as 

 long a distance as the length of the frontal triangle : posterior orbits 

 whitish pollinose, and with a fringe of white pile, longer below. Thorax 

 shining greenish black, the humeri and post-alar callosities sometimes 

 reddish; pile white, rather long and abundant. Scutellum yellow, very 

 translucent bluish opalescent, the pile in large ])art blackish. Abdomen 

 black, subopaque, with three pairs of arcuated whitish yellow spots, 

 rather uarrowlj' separated from each other, and more so from the lateral 

 margins; the spots on the third and fourth segments are oblique, deeply 

 concave in front, gently convex behind, inner ends rounded, api^roach- 

 ing the front borders of the segments, the outer ends broader, truncate; 

 fourth and fifth segments narrowly yellow behind; the first segment, 

 the hind margins of the second, third, and fourth, dilated in the middle, 

 and the remainder of the abdomen, more shining, somewhat metallic. 

 Legs reddish yellow ; basal half of front and middle femora and the hind 

 femora, except the tip, black; all the tarsi brown, sometimes blackish, 

 the metatarsi often reddish. Wings pure hyaline, the subcostal cell 

 light yellowish, third vein with a long, moderately deep curvature. 



Thirty specimens. 



The facial stripe sometimes extends to above the middle of the face; 

 the front of the female has sometimes a distinct brownish cast, and just 

 above the antennae not unfrequently brown. 



EUPEODES. 



Eupeodea Osten Sacken, West. Dipt., 328, 1877. 



Very like species of Syrphus, but differs in the terminal abdominal 

 segments. Head hemispherical ; eyes bare, extending the whole verti- 

 cal diameter, a little convergent below, without area of enlarged facets 



