4 PROCEEDINGS OF THE NATIONAL. MUSEUM. vol.64. 



Rostrum and palpi dark brown; antennae short, pale brown 

 throughout; flagellar segments with elongate verticils. Head dark 

 brownish gray. 



Pronotal scutellum conspicuously pale yellow. Mesonotmn dark 

 brown, the humeral region paler brown. Pleura and sternum con- 

 spicuously gray pruinose.- Halteres yellow, the knobs dark brown. 

 Legs v/ith the coxae and trochanters obscure brownish yellow; 

 remainder of the legs brown; legs relatively long and slender. Wings 

 pale brownish subhyaline; stigma conspicuous, brown; veins dark 

 brown, conspicuous. Venation as in 0. stylifer Alexander but the 

 cells distad of the cord are not quite so deep. 



Abdomen dark brown, including the hypopygium. Male hypopy- 

 gium very similar to that of 0. stylifer; pleural appendages larger and 

 more conspicuous, the apices of both more obtuse. 



Described from tliree males, collected at Clio, Plumas County, 

 California, July 9, 1916 (H. G. Dyar). 



Type.— Male, Cat. No. 26081, U.S.N.M. 



ERIOPTERA ALDRICHI, new species. 



Allied to E. Jcatmai Alexander; halteres pale, the knobs faintly 

 darkened; head blue-gray; wings faintly tinged with browm; stigma 

 elongate, dark brown; vein 2d A subsinuous, ending beyond mid- 

 length of Rs; male hypopygium concolorous with the remainder 

 of the abdomen; outer pleural appendage slender, the apex acute; 

 inner pleural appendage deeply bifid, the lateral arm strongly 

 curved, the mesal arm slender, pale, terminating in a single power- 

 ful seta; gonapophyses appearing as small, blackened plates that 

 are shorter than the penis-guard. 



Male. — -Length about 5 mm.; wing, 6.5 mm. 



Rostrum and palpi black. Antennae black, the first scapal 

 segment dusted with gray. Head clear blue-gray above, duller 

 gray on the genae. 



Pronotum clear gray; a setiferous area on either side of the scutum. 

 Mesonotal praescutum gray with four brown stripes that tend 

 to become confluent, only the lateral margins remaining of the ground- 

 color; pseudosutural foveae elongate, black, conspicuous; scutum 

 light gray medially, the centers of the lobes brown; scutellum light 

 gray, the margins weakly infuscated; postnotum gray. Pleura 

 clear gra}', the mesosternum and mesepimeron with conspicuous, 

 elongate, white setae. Halteres pale, the knobs weakly infuscated. 

 Legs with the coxae light gray; trochanters brown; remainder of 

 the legs black. Wings fully developed, faintly tinged with brown, 

 the costal and subcostal cells a little more yellowish; stigma elongate, 

 dark brown; veins dark brown, Sc yellowish. Venation: Sc^ ending 

 just before r; Sc^ faint, opposite three-fifths the length of Rs; Rn^s 



