Numerous specimens, Colorado.
Syrphus umbellatarum Schiner.
Five female specimens, Colorado. The only western locality heretofore given is Arizona (Williston).
Allograpta obliqua Say.
Five specimens, Colorado.
Mesogramma marginatum Say.
Numerous specimens from Colorado, showing very great variation.
Sphaerophoria cylindrica Say.
Twenty specimens, Colorado. I think the specimens belong here, though a positive identification is hardly possible at present.