1917] New Species of Colorado Syrphidce 223 



elongate oval with attenuated tips anteriorly which reach the lateral 

 margins of the abdomen, inner angles rounded; the second and third 

 pairs arcuate, a little oblique, convex behind, concave in front; outer 

 margins acute and directed forward, the inner angles rounded. The 

 fourth and fifth segments with a narrow yellow hind margin, the fifth 

 with two yellow basal marginal spots; legs yoUowish with base of 

 femora black; hind femora with more black than the rest; hind tibiae 

 and all tarsi brownish, lighter below. Wings hyaline, stigma brownish. 



Habitat: Two males, Fort Collins, Colorado. L. C. Bragg, 

 Collector. May 10, 1911. 



Note: — S. marginatus differs from S. arcuatus in that the 

 abdomen of the former is velvety black and sub-opaque, while 

 the latter is principally or wholly shining, and that the abdomi- 

 nal spots are dull yellow and the first pair reach the lateral 

 margin of marginatus, while the spots of the latter are bright 

 yellow and are all separated from the margin. 



Syrphus meadii n. sp. 



Length, male and female, 10 to 12 mm. Face pale yellowish, with a 

 shining black median stripe extending from oral margin but not reaching 

 the antennae; cheeks shining black, (from eye to oral margin); antenna 

 reddish brown, lighter on under side; frontal triangle yellow, pollinose, 

 black pile ; in the female with a medial black line resembling an inverted 

 Y, slightly convex. Immediately above the antennse are two large 

 black spots; frontal triangle in the male yellow, silvery pollinose, and 

 with black pile; vertical triangle black, black pile, eyes bare; occiput 

 in the female rather broad, silvery pollinose, and with whitish pile; 

 very narrow in the male. 



Abdomen black, principally shining black and yellow pilose, three 

 pairs of yellow cross-bands; the first abdominal cross-band distinctlv 

 interrupted and separated from the lateral margin, semi-oval, the inner 

 angles rounded, the latro-anterior angles slightly acute. Second and 

 third abdominal cross-bands coarctate in the middle ; a brownish medial 

 mark in the middle of these bands giving them the appearance of being 

 subinterrupted. These bands are concavo-sinuate anteriorly and con- 

 vexo-sinuate posteriorly. They do not reach the lateral margin and are 

 cut off obliquely forming a sharp angle anteriorly and are rounded 

 posteriorly. The fourth and fifth segments have a narrow yellowish 

 posterior border; fifth segment with two small yellowish triangular 

 spots at its base. The four anterior femora brownish with a black base, 

 the black extending about one-third the length of femora; hind femora 

 black with exception of apices which are brownish; tibiae brownish, 

 tarsi brown on underside, darker on top. Wings hyaline, subcostal cell 

 brownish, darker at stigma. 



Habitat: Eight specimens, seven females and one male. 

 C. S. Mead, Fort Collins, Colorado, June 12, 1913. 



