84 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



iacial tiilnMcIc; aiiteuiiic brown, reddisli on the uuder side ; fiout above 

 the autenuai .yellow, the augle between the eyes jiieenish black, yellow- 

 ish i)ruiuose, beset with black hair; small brown marks above the root of 

 the anteiiiiiB. Thorax metallic blnish-greeu, densely beset with yellow 

 pik' ; the broad geuimate, grayish stripe in the middle is subobsolete. 

 Scutellum yellowish metallic-opalesceut, beset with black pile. Abdo- 

 men black, oj)aque on the anterior, subo])aque on the ])osterior ])art of 

 the segments; the twoyellow spots on the second segment are i)r()longed 

 anteriorly, so as to reach the lateral margin of the segment at its an- 

 terior corner ; the two other cross-bands are rather narrow (not much 

 broader than one-fourth of the breadth of the segment), attenuated in 

 the middle (even subinterrupted in one of the specimens) ; their ends are 

 sei);irated from the lateral margin by a narrow black interval ; poste- 

 rioi- margin of the fourth segment with a narrow reddish border ; that of 

 the fifth still narrower. Legs reddish yellow; proximal half (or nearly 

 so) of the four anterior femora black; hind femora black, except at 

 tip : hind tarsi infuscated. Stigma brownish ; both costal cells dis- 

 tinctly tinged wiih brown. 



Two specimens. 



Female. I have two specimens, which I refer to this species, on ac- 

 count of their entirely yellow face and the course of the cross-bands, 

 which is nearly the same as in the males; but the femora are entirely 

 reddish yellow, coxae and trochanters remaining black. Vertex green- 

 ish black ; front metallic green, densely yellowish pollinose, its lower 

 part reddish yellow, except two brownish marks above the root of the 

 antennae." — Osten Sacken, 1. c. 



I have examined nearly fifty specimens of this species, male and fe- 

 male, from California, Oregon, and Washington Territory, which agree 

 closely with the above sufficiently full description. The yellow cheeks 

 and face, bare eyes, and the second and third abdominal cross-bands 

 not reaching the lateral margin will distinguish the species. 



Syrphus geniculatus. (Plate IV, tig. 3.) 



Syrjjhus geniculatus Macqnart, Dipt. Exot. , ii, 2, 101, 24; tab., xvii,fig. 5: Oa- 

 ten Sacken, Pioc. Boat. Soc. Nat. Hist., 1875, 159. 



Habitat. — Newfoundland (Macq.), White Mountains! 



$ . Length, 7.5 to 8°"". Eyes bare. Antennae unusually small for a 

 Syrphus, short, third joint nearly round ; black throughout. Face pro- 

 duced downward and forward, the tubercle prominent; dull yellowish 

 on the sides and below the antennae, but in large part obscured by a 

 greenish -black reflection, the yellowish part clothed with whitish pollen; 

 cheeks and lower ])artof the face greenish-black, extending up further 

 in the middle, shining on the tubercle. Frontal triangle greenish- 

 black, thickly covered with yellowish dust, and with long black pile; 

 vertex black. Thorax black, or dark brown with a faint, greenish 

 tinge, and with rather abundant black pile. Pleurae whitish dusted 

 and with light colored pile; scutellum obscurely yellowish, with black 



