No. 3.] HYGROCELEUTHUS AND DOLICHOPUS. 



133 



Numerous males and females examined from Arizona, Mon- 

 terey County, Cal., and Wyoming. It was described from San 

 Rafael, Cal., and is recorded also from Washington. 



The male of this species is very easily known by the presence 

 of the tufts of yellow hair upon the second abdominal segment. 



Hygroceleuthus ciliatus Aldrich. 



Afa/e. Length 4-5.5 mm. Face yellowish-white. Front green. Antennae 

 black, except lower half of first and second joints. Arista bare. Post- 

 ocular cilia black on upper third, below nearly white. Sides of first abdominal 

 segment with a few white hairs. Tips of hind tibiae blackish. Tarsi simple, 

 black from tip of first joint. Wings narrow, hyaline, costa not thickened at 

 tip of first longitudinal. Indention at 

 tip of fifth vein slight. Tegulae with 

 long black cilia. 



Female. Length 4-5.5 mm. Face 

 yellowish-gray. Arista of antennae bare. 

 Hind tibiae wholly yellow. First joint 

 of hind tarsi lighter at base. Tegular 

 cilia black. Wings with a distinct in- 

 cision at tip of fifth vein. 



Numerous specimens examined 

 from South Dakota and Wyoming. FlG ' m '~ H ' " liahts: a ' male; b > female < 



Hygroceleuthus idahoensis Aldrich. 



Male. Length 5.2 mm., of wing 4.8 

 mm. Face silvery. Antennae black, 

 not large but with swollen yellow pro- 

 tuberance on inner side ; second joint 

 slightly yellow on inner side ; arista 

 rather stout. Vertex blue-green. La- 

 mellae of hypopygium small, white, with 

 rather wide black margin. Anterior 

 coxae yellow with a dark green stripe 

 on outer face, and with a few hairs 

 on lower part. Hind tibiae incrassate with a longitudinal depression. 

 Tarsi black from tip of first joint. Costa thickened for a long distance, 

 the incision in hind margin slight. Tegular cilia pale, not large. 



Female. Face broader, darker than in the male. Anterior coxae more 

 hairy. Wings less yellow anteriorly, costa not thickened. Tegular cilia 

 larger, black with a slight admixture of pale ones. 



FIG. ii. //. idahoensis : a, male ; 

 l>, female. 



