CHARLES P. ALEXANDER 15 



4. Dark brownish black; legs dark browTi; wings uniformly suffused with 



dark, the veins ahnost black. (Guatemala) argenteopleura A\e\andeY^° 



Light bro^ai with a gray bloom; legs medium brown; wings subhyaline, 



the veins pale brown. (Colombia) andina sp. n. 



Genus ATARBA Osten Sacken 

 Atarba brunneicornis sp. n. 



Antennae brown; femora uniform in color throughout; wings very light j^el- 

 low. 



Male. — Length, 4.8 mm.; wing, 5.3 mm. 



Rostrum rather long, dark brown; palpi dark brownish black. Antennae 

 very long and slender, longer than the head and thorax together; the flagellar 

 segments elongated, covered with a thick white pubescence and with one long 

 hair on the outer face; antennae with the basal segments reddish brown, the 

 flagellum dark browTiish black. Head with a deUcate impressed line extending 

 from the occiput cephalad to a slight frontal tubercle which is provided in 

 front with two small hairs; head brown, thinly whitish polhnose. 



Thoracic dorsum dull yellow without apparent darker stripes. Pleura 

 whitish yellow. Halteres pale, the knob broA\-nish. Legs with the coxae and 

 trochanters dull yellow; femora yellow; tibiae and tarsi brownish yellow. 

 Wings very hght yellow, iridescent, a faint brown ill-defined suffusion in the 

 region of the stigma; veins pale brown. Venation: (see plate I, fig. 6) Sc end- 

 ing opposite the origm of Rs; Rs straight or nearly so, obhque; cell 1st Mi 

 twice as long as broad; basal deflection of Cui under the middle of cell 1st M-z. 



Abdominal tergites dark brown, the apex of the segments rather paler; 

 typopygium brownish yellow; sternites dull yellow. Hypopygium (see plate 

 IV, fig. 2) with the pleurites rather long and slender, bearing two chitinized 

 appendages, the ventral apical appendage rather flattened, the caudal or outer 

 edge with about five sharp teeth, the tip produced into a point; the dorsal 

 apical appendage is slender, subcyhndrical, curved shghtly dorsad, and 

 shghtly longer than the ventral appendage; guard of the penis a little shorter 

 than the pleurites, cyhndrical. 



Habitat. — Colombia. Holotype, d^, La Cuinbre, Colombia, 

 altitude 6600 feet, May 18, 1914 (Parish coll.). 



A. hrunneicornis is allied to A. co^wmfetana Alexander-^ also from 

 Colombia but the two forms may be separated by means of the 

 following key : 



Femora with a brown ring just before the tip; Rs longer, arcuated; cell 1st 

 Mo short and almost square; basal deflection o Cih just beyond the fork 

 of M. Columbiana Alexander^ 



20 1913. nrgenleopleura Alexander, Psyche, xx, p. 48, pi. 2, fig. f. 



21 Journ. N. Y. Ent. Soc, xxi, p. 199, 1913. 



22 1913. Columbiana Alexander, Journ. X. Y. Ent. Soc, xxi, \i. 199, pi. 5, 

 fig. 4. 



TRANS. AM. ENT. SOC, XLII. 



