S. W. Williston — North American Gonops. 329 



upper border of the disk of the metanotiim, and large spots in front 

 of the halteres nearly golden yellow, a small spot below each 

 humerus, and one above the root of the wing, less distinct, of the 

 same color. Upper portion of pleural stripe not distinctly defined. 

 Abdomen black, second segment mostly bi-ownish, its tip, and begin- 

 ning of the third, pure yellow ; first and second segments narrowly, 

 or indistinctly, dusted ; third, fourth and fifth with moderately broad 

 yellow hind borders; sixth segment covered on the end with yellow- 

 ish dust. Legs brown or black ; base and tips of femora and basal 

 portions of tibia^ yellow. Cox:ie and anterior tibiae on their outer 

 portions with a more golden satiny luster. Wings darker before 

 the third longitudinal vein, sub-hyaline behind ; the darker portion 

 nowhere with distinct outlines, a little clearer nearer the humeral 

 cross-vein ; slightly darker, narrow clouds before the fifth and sixth 

 veins. Posterior cross-vein at right angles. Long. Corp., 8-10""". 

 Five specimens, Va. (Davis) ; S, (.^a., Ga. (Morrison) ; Mass. (Burgess). 



Conops sylvosus, u. sp. 



c . Face obscure white, or yellow, with a broad border of silvery 

 dust near the orbit, extending, obliquely narrowed, to near the ver- 

 tex ; facial grooves not darkened. Cheeks like the face, oral border 

 sharp. Front obscurely, or quite black, extending down on the 

 sides of the base of the antenna^. Vertical callosity black, or red- 

 dish-black, flattened, extending far forward. Antenna3 black, red on 

 the under sides, third joint as long as second, first joint more than 

 half as long. Second joint of style projecting very little, third joint 

 rather short, with a very brief bristle-like end. Proboscis brownish 

 black, scarcely as long as the two last joints of the antenna?. Occiput 

 black ; orbits, except on the upper part bordered with yellowish dust. 

 Thorax black, shining; inner sides of liumeri, disk and sides of 

 metanotiim, faintly dusted with white. Abdomen black, shining; sides 

 of the second segment more or less red. All the segments, except 

 the sixth, with nearly uniform, rather narrow, yellowish white hind 

 borders; fifth, and especially the sixth, dusted with whitish. Legs 

 black ; coxae, particularly the first pair in front, and a small spot 

 near the tip of each of the anterior tibiae, with satiny white luster. 

 Extreme base and tips of femora, red or yellow ; basal three-fifths of 

 anterior, and two-fifths of hind tibiae, light yellow ; distal portions and 

 tarsi, reddish brown. Wings light brown and pure hyaline, costal 

 cell scarcely lighter; the brown is limited by the third longitudinal 



