18S2.] 313 [VVillistou. 



of the two tables given by Ostcn Sacken (Proc. Best. Soc. N. H., 1875, 

 p. 138, and West. Dipt., p. 325), united, with the addition of the species 

 herein described. 



Sykphus. 



a. — Second and third cross bands of abdomen never interrupted h. 



— Three principal cross-bands broadly interrupted i. 



b. — First cross-band broadly and distinctly interrupted in both sexes c. 



—First cross-band narrowly interrupted in the male ; not interrupted in 

 the female /'• 



c. — Abdomen elongated, narrrow, linear dicersipes. 



— Abdomen oval d- 



d. — Femora black at the base e. 



—Femora yellow at the base ribesii ? , protritus. 



e. — Abdominal cross-bands do not reach the lateral margins g. 



— Abdominal cross-bands reach quite the lateral margins. ./. 



/. —Eyes pubescent torvus. 



—Eyes glabrous ribesii (S". 



g. — Cross bands attenuated on the sides opinator. 



— Cross-bands reach the sides in nearly their full width ; not attenuated 



near the ends Lesueurii. 



h. — Face yellow abbrematus. 



— Face with brown stripe americanus. 



i. — Abdomen elongated, narrow, linear j. 



— Abdomen oval I. 



j. —Eyes pubescent velutinus, sp. nov. 



Eyes glabrous ^■• 



k. — Anteunse inserted on yellow ground umbellatarum. 



— Antennae inserted on black ground geniculatus. 



I. — Eyes pubescent in. 



—Eyes glabrous «• 



m. — Abdominal spots straight n. 



— Abdominal s^Dots coarctate in the middle, sometimes broken in two ; 



face conspicuously brown or black in the middle \ ■ . j 



n. — Face yellow ; third longitudinal vein straight coniumax. 



— Facial stripe and front black velutinus, sp. nov. 



0. — Abdominal spots lunate, face with black on the tubercle . .lapponicus. 

 — Abdominal spots straight, face without black disjunctus, sp. nov. 



Strphus lappqkicus Zett., Dipt., Scand. ii, 701, 8. Wyoming Terr., 

 Kansas, Oregon, Southern California, New England ! Greenland, Europe. 

 Specimens taken in Connecticut, late in October, have the sinuosity of the 

 third vein as stronglj^ marked as in any Western ones. The species is 

 widespread and common. 



Syrphus opinator 0. S., West. Dipt., 327, Oregon, Washington Terr., 



