PORPHYROPS. 145 



* 



difference in the color as only accidental, as it so often occurs in 

 the Dolichopodidse. Face moderately broad, with silvery-white 

 dust. Palpi black with white dust. Antennas short, the third 

 joint small and ovate ; arista three times the length of the anten- 

 nas. Front blue with thin white dust. Upper side of the thorax 

 steel-blue, upon the middle and towards the hind margin more 

 violet. The steel-blue scutellurn upon its middle is also of a vio- 

 let color. The abdomen is dark metallic-green, its last segment 

 rather black-green at the basis, otherwise bright steel-blue. The 

 hairs on the fore coxae are like those of the male, only less dense 

 and shorter ; the hair on the middle coxae is also whitish, the weak 

 bristles in the vicinity of its tip are, however, black. The wings 

 are the same as those of the males, only the blackening of the 

 second part of the fore margin is stronger and the fourth longitu- 

 dinal vein with the posterior transverse vein have a darker seam. 

 The remainder like in the male. 



Hab. District Columbia. (Osten-Sacken.) 



2. P. nigricoxa LOEW. Pedibus flavis, coxis omnibus et totis 



nigris. 

 Feet yellow, all the coxae entirely black. Long. corp. 0.22. Long. al. 



0.23. 

 STN. Porphyrops nigricoxa LOEW, Neue Beitr. VIII, 51, 2. 



Female. Metallic-green, front, thorax and scutellum very cop- 

 pery. Face with yellowish-gray dust ; the separation between its 

 upper and lower part is particularly striking. Palpi compara- 

 tively small, black with yellowish-gray dust ; antennae black ; third 

 joint ovate ; arista 1^ the length of the antenna?. Front with 

 thin yellowish-gray dust. Cilia on the upper orbit black, on the 

 lateral and inferior orbits white. All the coxae entirely black, with 

 gray dust and whitish hair ; at the end of the fore and middle 

 coxae there are no black bristles. Feet yellow, apical half of the 

 hind femora black, the last third of the hind tibia; and the hind 

 tarsi altogether are of the same color; middle and fore tarsi 

 strongly infuscated from the root and towards the end black. 

 Cilia of the yellowish tegulae white. Halteres pale-yellowish. 

 Wings gray, on the fore margin more brownish gray ; the last 

 segment of the fourth longitudinal vein, beyond the middle, gently 

 inflected forward. 



Hob. Maryland. (Osten-Sacken.) 

 10 



