70 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



Female. Front aud vertex metallic greenish black; s])ots on second 

 segment coarctate in the middle, those on segments three and fonr dis- 

 solved in two, so that these two segments show each a transverse row 

 of yellow spots, nearly of the same size and equidistant ; the fifth seg- 

 ment has two spots at the base; the wings are hyaline. In all other 

 respects like the male. 



Two males and one female. 



I have not the slightest doubt that these males and females belong 

 together; the difference in the coloring of the wings has no importance; 

 as to that in the coloring of the abdomen, I should not wonder if this 

 species proved to be very variable in this respect, and if intermediate 

 stages occurred between that where the lunate spots are entire and 

 where they are dissolved in two. The abdomen in this species is more 

 convex broader and somewhat shorter than that of S. lapponieus. 



In the specimens described above, the yellow abdominal markings 

 do not come in contact with the lateral margin. But I have a pair of 

 specimens (5,9) from the same locality in which this contact occurs. 

 In the female the spots are also cut in two as they are in the typical 

 specimens," — Osten Sackeu, 1. c. 



I have three female specimens from Connecticut (June 11), on blos- 

 soms of Prunus virginianiis, that seem to be intermediate between this 

 species and the next, S. intrudois, but agreeing rather better with the 

 description of S. intrudcns. The facial stripe is black, narrower than 

 the yellow portion on the sides. The antenuce are wholly reddish yel- 

 low; in one specimen only, the third joint is brown ; the front has a white 

 pollinose interrupted cross-band ; the pile of the scutellum is partly or 

 •wholly yellowish. The abdomen is very shining, all the spots attain the 

 lateral margin, those of the third and fourth segments are, in one speci- 

 men, only deeply excised, in the other two specimens dissolved into two 

 spots; the spots on the second segment are broadly oval and not at all 

 excised in front. The legs are light yellow ; the front and middle femora 

 at the base, and the hind femora on the basal half, are black; the hind 

 tibiae with a brownish ring, and the hind tarsi in one specimen brown- 

 ish. A single female from New Mexico (G. F. Gaumer) seems to agree 

 perfectly with the descrijitiou. The spots on the first segment are ex- 

 cised in front, and those on the third and fourth segments are not cut 

 in two and reach the lateral margin distinctly. The species, as Osten 

 Sacken says, is evidently a variable one, and I am inclined to doubt the 

 validity of S. inirudens. 



Syrphus intrudens. 



<bi'»^rj;/(».v inirudeha Osten Sackeu, AVest. Dipt., '32G, 1877. 



Habitat^ — California (O. S.). 



"Length about 10""". Male. Eyes pubescent; face brownish yellow, 

 with a broad black stripe in the middle, abbreviated before the antennae, 

 aud narrower than the yellow portion of the face on each side of it; 

 the black is prolonged along the oral border to the black cheeks, which 



