SYNOPSIS OF NORTH AMERICAN SYRPHID^. 179 



more ochraceous, an elongate median spot, and the cheeks in front, 

 shining black; in profile gently concave below the antenna^., the tnbercle 

 nose-like. Frontal triangle very projecting in profile, obtusely angnlated 

 in the middle; shining black, with black pile; the white dust of the face 

 extends up narrowly along the eyes. Dorsum of tiliorax opaque black, 

 the anterior border and a narrow transverse baud on the suture gray- 

 ish-yellowish polliuose, in front of the scutelluni a broad subquadrate 

 area shining, deep metallic blue. Pleurse thickly grayish polliuose be- 

 low; on the mesopleurte with yellow pile, which extends up to the end of 

 the transverse band. Scutellum light opaque yellow with short sparse 

 black pile; at the base rather narrowly opaque black. Abdomen 

 brownish black, opaque, with two pairs of large quadrilateral yellow 

 spots; the black of the second segment is a little broader in front, and 

 extends outward behind rather narrowly and acutely to the lateral 

 margin ; spots on the third segment subquadrate, touching the anterior 

 margin, and separated by about their own width ; fourth segment with 

 abluish, metallic, subinterrupted, shining cross-band; second, third, and 

 fourth segments with a narrow yellow hind margin. Hypopygium 

 wholly shining black. Legs black, tibiie and tarsi reddish brown. 

 Wings lightly infuscate on distal half, and with an obscure brownish 

 spot. 



Four specimens, New Mexico (Mr. G. F. Gaumer). I take pleasure in 

 dedicating this beautiful species to Prof. C. V. Riley. 



ADDITIONAL NORTH AMERICAN SPECIES. 



Doliosyrphus hirtipes Bigot, Bull. Soc. Ent. de Fr., 1882; Ann. Soc. Eut. de Fr., 



1883, 343. Panama. 

 Doliosyrphus scutellatiis Bigot, Bulletin Soc. Ent. de Fr., 1882; Ann. Soc. Ent. de 



Fr., 1883, 342. Panama. 



PTEROPTILA.* 



Plagiocera Macquart (uon King), Dipt. Exot., ii, 2, al), 1842. 

 Pteroptila Loew, Gentnr., vi, 59, 1865. 



Large, robust, nearly bare species, with bright yellow markings of 

 very short pile on thorax and abdomen. Head hemispherical, a little 

 broader than the thorax. Eyes in male contiguous, bare; antennae 

 small, third joint oval, first two joints short. Face nearly perpendicu- 

 lar, below the antennae a little receding, not much produced below the 

 eyes, very slightly tuberculate. Thorax somewhat narrowed in front ; 

 scutellum broad. Abdomen moderately longer than the thorax, the 

 hypopygium large, uusymmetrical. Legs moderately stout, the hind 

 femora considerably thickened, without spines or proturberances below. 

 Wings dark colored in front, clothed with microscopic pile ; the third 

 vein bent deeply into the first posterior cell ; marginal cell closed and 

 petiolate; anterior cross-vein beyond the middle of discal cell. 



^Hrefjov, wing, and tttMv, plumage. 



