330 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



ver, Clear Creek, etc.. Colo., August (P. R. Ukler) ; Spanish Peaks, 

 Colo., June 15 (W. L. Carpenter). More than two dozen specimens of 

 both sexes. 



Mesograpta geminata (Say), Journ. Acad. Phil., iii, 92, 7 (Scceva). — 

 Occurs both in the Atlantic and Pacific States (San Rafael, Cal., April, 

 May ; Yoseurite, June). 



Mesogkapta marginata (Say), Journ. Acad. Phil., iii, 92, 6, (Scwva).— 

 Common on both coasts (Los Angeles, Cal., in February ; Webber Lake, 

 Sierra Nevada, in July) ; also in Denver, Col. (Uhler). Is not Syrphus 

 limbiventris Thomson (Eugenies Resa, 495) simply a variety of this 

 species ? 



Sph^rophoria sulphuripes (Thomson), Eugenies Resa, 500 (Syr- 

 phus). — Specimens ( 9 ) from San Rafael, May 29, and Yosemite, June 14, 

 agree with Mr. Thomson's description. The cross-band on the fourth 

 segment is sometimes interrupted. Whether the male specimen de- 

 scribed by Mr. Thomson belongs here seems doubtful. I have males 

 with entirely yellow coxae, like those of the female ; the cross-bands or 

 segments 2 and 3 are not interrupted, and reach the lateral margin ; 

 segments 4-6 are reddish, with brownish marks. In other males, the 

 hind coxae are dark, but with a yellow spot behind ; the cross-bands are 

 laterally interrupted before reaching the margin. I also have specimens 

 with a brown stripe over the face, dark femora, and hypopygium. 



California seems bo be rich in species of this group, richer than the 

 Atlantic States; and in this it again resembles Europe. In Europe, the 

 definition of the species of Sphcerophoria is, as yet, an unsolved prob- 

 lem ; they seem to be very variable in their coloring, aud it would not 

 be safe to multiply descriptions of Californian species based on color- 

 ing only. It seems doubtful to me whether the Syrphus infuscatus 

 Thomson is not the same species as his sulphuripes, and I am not at all 

 sure whether the latter is not identical with the common Sphcerophoria 

 cylindriea of the Atlantic States. 



Among the several species of this genus which I have before me, I 

 will describe only one, which has very marked characters to distin- 

 guish it. 



Sphcerophoria micrura n. sp. — Male. — Face of a somewhat livid yel- 

 low, with a brown stripe in the middle; front above the antennas, with a 

 large semicircular greenish-metallic spot; the interval between this spot 

 and the eyes is yellow; antennas brown, third joint reddish at the base 

 and on the under side; cheeks metallic blackish-green, but oral margin 

 yellow. Thorax dark metallic-green, with the usual autealar humeral yel- 

 low stripes; scutellum yellow, with black pile; pleurae dark metallic, some- 

 what bluish; abdomen black ; first segment with a very narrow basal yel- 

 low margin; segments 2-4 each with a straight yellow cross-band, reaching 

 the lateral margin, and framed in anteriorly and posteriorly in velvet-black, 

 opaque cross-bands; the hind margins of the segments are shining bluish- 

 black; the cross-band on segment 2 is narrower than the two others, and 



