DIAPIIORUS. 163- 



above the antennae. Cilia on the upper orbit black, on the lower 

 and lateral orbits white. Upper side of the thorax and scutellum 

 covered with yellow-brownish dust. The stouter bristles on the 

 posterior end of the very small hypopygium rather striking ; its 

 exterior appendages brown and very small. Coxae black and with 

 whitish dust ; the hair on the fore coxae appears in most directions 

 black, in others fallow-brownish. Femora black, somewhat with a 

 green reflection ; the tip of the fore and middle femora brownish- 

 yellow; their black hair, even .on the under side, neither of con- 

 siderable length nor density. Tibiae brownish-yellow, rather 

 slender, with a few bristles. Fore tarsi very slender, from the tip 

 of the first joint black-brown, though the basis of the second joint 

 is again paler than the tip of the first ; their first joint is as long 

 as the other four together ; the pulvilli are very much enlarged 

 and elongated. Middle tarsi of ah entirely similar structure, of 

 the same color, but their pulvilli are somewhat less enlarged ; 

 hind tarsi from the tip of the first joint black-brown, their pulvilli 

 but very little enlarged ; the yellowish tegulse with blackish cilia, 

 which assume a yellowish glitter in a reflected light. Halteres 

 yellowish, the tip of their knob usually somewhat infuscated. 

 Wings tinged with gray, with blackish-brown veins, along which, 

 in faded specimens, there are blackish-brown margins ; they are 

 broad, though their greatest breadth is not very close to the pos- 

 terior angle ; the space between the third and fourth longitudinal 

 veins is rather wide ; the last segment of the latter shows a very 

 gentle flexure ; posterior transverse vein rather long and somewhat 

 beyond the middle of the wing ; the first longitudinal vein reaches 

 somewhat beyond the first third of the whole length of the wings 

 and is not very far distant from the anterior margin. 

 Hob. District Columbia. (Osten-Sacken.) 



II. THE EYES OP T.HE MALE NOT CONTIGUOUS UPON THE FRONT. 



A. The last segment of the fourth longitudinal vein not interrupted. 



4. D. sodalis LOEW. and 9 Aeneo-viridis, femoribus nigris, 

 tibiis omnibus tarsorumque anteriorum basi flavis, tarsis posticis totis ex 

 nigro fuscis, ciliis tegularum nigris, oculis niaris in fronte separates. 



Bronze-green ; femora black ; all the tibise and the basis of the four ante- 

 rior tarsi yellow ; all the hind tarsi black-brown ; cilia of the tegulse 



