ADAMS : DIPTEROLOGICAL CONTRIBUTIONS. 41 



teniiae rounded, arista yellow at base, whitish at tip, frontal 

 triangle does not reach anterior border of front, the latter bear- 

 ing a few black hairs ; mesonotum with the usual three broad, 

 black stripes and the two narrow ones above base of wings, pile 

 black, humeri each with a black dot, pleurae yellow, marked 

 with six black spots, scutellum yellow, blackish on sides at 

 base, halteres yellow ; legs yellow, a spot on base of front coxiv, 

 one on top of each femora, the posterior tibiae near middle, 

 front tarsi wholly, and middle and hind tarsi except base, 

 brownish black ; abdomen brownish black, base of first seg- 

 ment, lateral margins and tip of last segment yellow, venter 

 brown ; wings hyaline, second and third veins straight, hind 

 cross-vein more than its length from the small. Length, 5 mm. 

 Four specimens ; Lusk, Wyo. Collected by W. A. Snow and 

 Hugo Kahl. 



Chlorops recurva, o. ep. 



Head yellow, occiput in the middle, and narrowly in the 

 middle of the sides, the short frontal triangle, the rounded 

 third antennal joint, with base of arista, and cypleus, black ; 

 first two antennal joints and terminal portion of arista brown- 

 ish yellow, palpi yellow ; mesonotum yellow, with the usual 

 three broad and two narrow black stripes, humeri each with a 

 black dot, another black dot behind the humeri, and on the ex- 

 treme lateral margin is a brown line running from the humeri 

 to the base of the wing, pleurae yellow, with six black spots, 

 scutellum narrowly yellow in the middle, dark brown on the 

 sides, halteres whitish yellow; legs reddish yellow throughout, 

 tips of tarsi fuscous ; abdomen brownish black, apex and venter 

 yellowish; wings hyaline, second and third veins curved for- 

 ward, cross-veins approximated. Length, 3.4 mm. 



One specimen ; Lusk, Wyo. Collected by W. A. Snow. 



Chlorops halteralis, n. Bp. 



Head yellow, occiput except sides, the narrow, elongate, 

 frontal triangle, the rounded third antennal joint with the 

 arista, and clypeus on the sides, black, face whitish yellow, 

 palpi yellow; thorax yellow, five dorsal vittae, two humeral 

 dots, four spots on pleurae, and metanotum, shining black, 

 halteres whitish ; legs yellow, tips of tarsi fuscous ; abdomen 

 shining brownish black, lateral margins, apices of segments 



