330 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



ver, Clear Creek, etc., Colo., August (P. E. Uhler) ; Spanish Peaks, 

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

 both sexes. 



Mesogkapta geminata (Say), Journ. Acad. Phil., iii, 92, 7 {8ca;va). — 

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

 May ; Tosemite, June). 



Mesograpta marginata (Say), Journ. Acad. Phil., iii, 92, 6, (Scceva). — 

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

 Sierra liJ'evada, in July); also in Denver, Col. (Uhler). Is not Syrplms 

 Umhiventris Thomson (Eugenics Eesa, 495) simply a variety of this 

 species ? 



Sph^rophoria sulphuripes (Thomson), Eugenics Resa, 500 {8i/r- 

 jphus). — 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 coxse, 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 C0X8B 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 to 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, and it would not 

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

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

 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. 



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

 low, with a brown stripe in the middle; front above the antennae, 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 antealar 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, reachi n g 

 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 



