Vol. IX] VAN DUZEE— NORTH AMERICAN MEDETERUS 265 



of acrostichal bristles shining bluish green as is also the center of the 

 scutellum ; scutellum with one pair of bristles and a pair of small hairs on 

 the margin; abdomen more green and shining than the thorax; coxae and 

 jfemora black ; extreme tips of the femora, the tibiae and tarsi yellow ; tarsi 

 a Httle darker at tips; second joint of hind tarsi nearly twice as long as 

 first; tegulae, their cilia and the halteres yellow; wings hyaline slighdy 

 tinged with y€llowish gray ; veins yellowish brown ; costa brown ; last sec- 

 tion of fifth vein a little longer than the cross-vein. 



Described from one female taken by me at East Aurora, 

 Erie Co., N. Y., July 28, 1915. 



A stout little species with the thorax rather thick and the 

 scutellum with one pair of bristles. 



Holotype, female, in collection of the author. 



9. Medeterus aequalis, new species 



Male and female : Length 2 mm. Face narrow, brown ; proboscis shin- 

 ing black, rather small ; antennae black, small ; thorax coppery, with thick 

 gray pollen, leaving a rather sharpy defined median vitta which extends to 

 the scutellum but is not very distinct on the depressed area, and a lateral, 

 broad, not distinctly defined vitta on each side of the dorsum; acrostichal 

 bristles represented by a few small bristles in front; bristles above fore 

 coxae black, very small ; scutellum with one pair of bristles ; in the female 

 some of the bristles of the thorax are yellowish; abdomen shining black 

 but dulled with gray pollen ; hypopygium long and slender, shining black ; 

 coxae and legs black; knees and fore tibiae more yellowish; second joint 

 of hind tarsi one and a half times as long as the first; tegulae, their cilia 

 and the knobs of the halteres yellow; wings grayish hyaline; distal seg- 

 ment of fifth vein only a little longer than the cross-vein; fourth vein 

 ending just before the tip of the wing and close to the tip of the third 

 vein ; veins black, only a little paler at the root of the wing. 



Described from two males and one female taken by me at 

 San Diego, Calif., Apr. 5 and 12, 1915. 



Holotype, male (No. 516), in collection of the California 

 Academy of Sciences. Allotype, female, and paratype in col- 

 lection of the author. 



10. Medeterus frontalis, new species 



Female : Length 3 mm., of wing the same. Face black, below the suture 

 slightly greenish and shining; front thickly covered with brown pollen 

 except a narrow border of gray pollen along the orbits ; palpi and proboscis 

 not very large, black with pale hairs; antennae black, small, third joint 

 very small ; arista almost dorsal, as long as the height of the head ; lower 

 orbital cilia yellow ; thorax with greenish ground color, thickly covered 

 with pollen which is brown on the center of the dorsum and more gray on 

 the posterior depressed area, scutellum and pleurae ; bristles well developed ; 

 acrostichal bristles strong, in two rows ; scutellum with two pair of bristles, 

 the outer pair about half as large as the central ; bristles above fore coxae 

 small, black ; abdomen shining black, with black hairs ; legs black with only 

 the tips of the femora yellow; fore coxae with minute pale hairs and small 



