NO. 1866. NEW SA^yFLIES IN U. S. NATIONAL MUSEUM— ROIIWER. 381 



middle fovea wanting; a U-shaped depressed area in the middle of 



the face below the crest; antennal furrows complete, well defined; 



area around the anterior 



ocellus hardly depressed ; 



postocellar furrow deep; 



postocellar line a very little 



shorter than the ocellorbital 



line; third antennal joint 



curved; head dulled with 



fine scratches ; stigma broad, 



rounded on the lower mar- 



, ^, J, , , , Fig. 2.— Radial VENATION OF NiTHULEA NIGEATA ROHWER. 



gm ; sheath rather broad and 



robust. Entirely black ; wings dusky hyaline ; venation brown, stigma 



pale brown. 



Chubut, Patagonia. One female collected by W. F. H. Rosenberg. 



Type.— Csit. No. 13987, U.S.N.M. 



Genus LOBOCERAS Kirby. 



LOBOCERAS TRIMACULATUM, new species. 



Apparently more closely related to some of the Brazilian species, 

 Lohoceras trinotatus Konow, etc., than any of the Central American 

 forms, but does not agree "wdth any of these. In color it is more 

 like Lohoceras varicone Cameron than the other described species 

 from Central America. 



Female. — Length 8.5 mm. ; length of anterior wmg 8 mm. Labrum 

 nearly as long as wide, rounded at the apex; clypeus nearly truncate; 

 ocellar basin open below and extending to the open middle fovea, 

 making a broad, shallow facial fovea; antennal furrow not com- 

 plete; posterior orbits not as broad as in L. mexicanum Kirby; 

 postocellar area well defined, the lateral furrows not reaching the 

 posterior margin of the head; third antennal joint distinctly longer 

 than the fourth, but not as long as four plus five ; scutellum margined 

 laterally and not depressed in the apical middle; second cubital cell, 

 much broader above than below, receiving the first recurrent slightly 

 beyond the middle; second recurrent slightly beyond the second 

 transverse cubitus; legs normal; sheath well concealed, truncate at 

 the apex. Luteous; head, except pallid labrum, clypeus, supra- 

 clypeal area, scape, mandibles (apicies piceous), and antennae black; 

 a brownish spot on each lobe of mesonotum; intermediate tarsi and 

 the posterior tibias and tarsi black. Wings yellowish hyaline, beyond 

 the stigma dusky hyaline; venation to apex of stigma yellowish, in 

 the dusky part of the wing brownish. 



Piedros Negras, Costa Rica. One female collected by Schild and 

 Burgdorf. 



Type.— Csit. No. 13988, U.S.N.M. 



