172 DIPTEROUS GENUS DIAPHORUS 



Male : Length 2.5-3 mm. Eyes contiguous ; antennae black, 

 third joint small, rounded at tip ; arista subapical, or perhaps bet- 

 ter described as dorsal. Thorax black, dorsum covered with 

 brown pollen, opaque. Abdomen shining, black, bristles at tip 

 large. Coxae and femora black ; tibiae yellow, sometimes yellow- 

 ish brown ; tarsi yellow at base, brown ' at tip ; fore pulvilli but 

 little enlarged. Tegulae, their cilia and the halters black. Wings 

 tinged with brown ; first vein reaching about two-fifths of the 

 distance to the tip of the second vein, (Loew states that the first 

 vein reaches nearly to the middle of the front margin, but in all 

 the specimens I have seen which answer his description of opacus 

 it does not reach so far). I have seen specimens from Vt., 

 N. Y., Pa., and Toronto, Ont. 



9 Diaphorus adustus n. sp. 



Male: Length 2.5 mm. Altogether black except that the 

 thorax has a very slight greenish, tint, and the knees are very 

 narrowly yellowish, body and legs somewhat shining ; face and 

 thorax with brown pollen ; pleurae with gray pollen ; eyes nar- 

 rowly contiguous, or scarcely touching on the front; antennae 

 black, third joint very small ; arista dorsal ; bristles at the tip of 

 the abdomen strong. Middle tibiae with the bristle near the 

 knee rather small ; hind tibiae with four or five small bristles on 

 the upper surface ; pulvilli of fore tarsi enlarged, yellowish 

 brown. Wings tinted with brownish ; first vein reaching about 

 two-fifths of the distance to the tip of the second vein ; costa 

 , scarcely enlarged beyond the tip of the first vein. 



Described from three males from Idaho and Nev., the latter 

 taken July 12th. Type in J. M. Aldrich collection. 



The relation of this species to opticus Loew is very close, 

 but it is separated from that species by the altogether black 

 legs, and the more shining thorax with its slight greenish tint, in 

 opacus the tibiae are yellow or brownish yellow, if the tibiae 

 are brown in adustus they are of the same shade as the femora 

 and are not yellowish brown ; from D. gibbosus it is more widely 

 separated by the longer first vein, more thickened costa, and more 

 arched thorax of gibbosus u.sp. 



