Vol. IX] VAN DUZEE— NORTH AMERICAN MEDETERUS 267 



pollen; marked with a quite distinct median, shining bronze vitta between 

 the rows of acrostichal bristles, continued as a faint brownish line across 

 the posterior depressed area and slight indications of lateral vittae; bristles 

 above fore coxae black, small ; scutellum with two pairs of bristles, the 

 outer being nearly as large as the central pair, the latter not as long as in 

 some species. Abdomen dark green, almost black, shining but dulled with 

 pollen ; coxae black ; legs brown with very short hairs ; knees a little yel- 

 lowish ; tibiae without bristles except a very small one on middle tibiae at 

 basal third; 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 tinged 

 with brownish, especially on the basal half; veins brown; the tips of third 

 and fourth veins rather close together; last section of fifth vein a little 

 longer than the cross-vein. 



Described from one female taken on the Berkeley Hills, in 

 Alameda Co., Calif,, June 20, by E. T. Cresson, Jr. 



Holotype, female (No. 6116), in collection of the American 

 Entomological Society. 



13. Medeterus halteralis, new species 



Male : Length 2.25 mm. Altogether black ; face shining black below the 

 suture ; upper part of the face and the front opaque with brown pollen ; 

 cilia of the lower orbit pale brownish ; proboscis large, shining black ; 

 thorax black, dorsum thickly and uniformly covered with brown pollen; 

 acrostichal bristles in two rows, small ; besides the larger bristles there are 

 some scattering small ones on the fore part of the dorsum. Pleurae and 

 abdomen a little shining, the latter with black hairs ; bristles above fore 

 coxae blackish, slender; scutellum with four bristles; hypopygium rather 

 short, black, somewhat shining ; its appendages long, brownish ; coxae and 

 legs black ; fore coxae with minute brown hairs on the front surface ; hind 

 metatarsi half as long as the second joint; tegulas yellowish brown with a 

 brown border and yellowish cilia; stem of the halteres yellowish brown, 

 knob blackish. Wings grayish hyaline ; veins black ; last section of fifth 

 vein about equal in length to the cross-vein ; root of the wing yellowish 

 brown. 



Female : Length 2.75 mm. Legs paler, root of wings, halteres and 

 tegulae, except the brown border, more yellowish; the bristles above the 

 fore coxae dingy white; ovipositor blackish. 



This female seems to be somewhat immature and although 

 taken on the same tree and at the same time as the male de- 

 scribed above it may prove to be a distinct species. 



Described from one male and one female which I took at 

 Brule Lake, Ont, Aug. 2, 1911. 



This species is very close to M. modestus V. D. (Ent. News, 

 Vol. XXV, p. 440), but this male has blackish bristles above the 

 fore coxae while modestus has conspicuous white bristles; the 

 lower part of the face also is more blackish and the halteres 

 are more infuscated in this species. 



Holotype, male, in collection of the author. 



