286 DIPTERA OF NORTH AMERICA. [PART II. 



2. Middle and hind coxae blackish. 



21 • P. tfilipes Loew. % . — Gracilis, longipes, nitidus, capite, thorace 

 scutelloque chalybeis, abdomine viridi, proboscide, duobus primis an- 

 tennarum articulis, coxis pedibusque flavis, femoruni intermediorum 

 basi nigra, tibiis intermediis tarsisque omnibus fuscis. 



Slender, long-legged, shining, head, thorax and scutellum steel-blue, ab- 

 domen green ; proboscis, the two first joints of the antennse, coxae and 

 feet yellow, still the basis of the middle femora blackish ; middle tibiae 

 and all tarsi brown. Long. corp. 0.26. Long. al. 0.26. 



Syn. Psilopus Jilipes Loew, Neue Beitr. VIII, 99, 18. 



Of slender shape and very long-legged, shining. Head pur- 

 plish-blue ; proboscis yellow, palpi brown, both beset with minute 

 light hairs. Face without hairs, very broad, covered with dense 

 yellowish dust ; its upper part is quite unusually convex. The 

 two first joints of the antennae yellow, the second fringed with 

 short minute white-yellowish hairs ; the small third joint rounded, 

 brownish-black; arista dorsal, proportionally of insignificant 

 length. Front without hairs, with grayish-yellow dust, which 

 does not cover the shining purplish ground-color upon the middle ; 

 the usual black bristles of moderate length. Thorax and scutel- 

 lum shining purplish-blue, with a yellowish dust, which does not 

 cover the lustre of the ground-color. The black bristles of the tho- 

 rax rather long. The scutellum has but two bristles, still near the 

 lateral corners, on its margin, some long hairs are inserted. Ab- 

 domen shining green with a very slight yellowish dust ; if the light 

 falls upon it from behind, narrow black fasciae on the anterior mar- 

 gins of the segments become apparent, which are invisible, if the 

 light falls from the opposite side. The delicate pubescence of the 

 abdomen is whitish ; upon the upper side of the two first segments, 

 on the lateral margin and on the venter very long, otherwise 

 short ; black bristles of moderate length are only to be found 

 before the hind margin of the third and of the following segments. 

 Hypopygium blackish-green with white dust ; the external ap- 

 pendages sty liform, but little shorter than the inner ones, their 

 basal half light-brownish and hairy, their apical half white and 

 glabrous, their extreme tip black ; the inner appendages form a 

 brownish-black forceps. Fore coxae yellowish with a yellowish- 

 white pubescence, which has on their outside a rather unusual 

 length ; there are no bristles upon it. Middle and hind coxae 



