112 D. W. COQUILLETT. 



% . — Same as the 9 > except that the bristles of antennse, pile of face aurt sev- 

 eral on the vertex are black and the thorax is destitute of stripes of gray polleu. 

 Length 4 mm. 



Southern California. A single male and female, in April and July. 



Oeron tiybiis n. sp. % 9 .--Opaque black, knob of halteres light yellow. 

 Head and body light gray pollinose, two spots on upper part of occiput, two 

 stripes on thorax, scutellum, except each side, and abdomen except first segment, 

 opaque black. Pile and tomeutum of head white, a few of the pile on antennse 

 and occiput black; depressed tomentum on upperside of body of female yellow 

 (wanting in the male), the pile white, with a few black ones intermixed. First 

 antennal joint over twice as long as the second, both are provided with bristles 

 above and below ; the female these scarcely exceed the length the width of these 

 joints, but in the male they are nearly three times as long; third joint three 

 times as long as the first, gradually tapering to the tip, destitute of bristles. 

 Proboscis slightly longer than the thorax. Wings hyaline, apex of subcostal 

 cell yellowish, last two sections of the third vein subequal in length, posterior 

 cross-vein sinuous. Length 4 mm. 



Southern California. Three males and four females, in July. 



