J. R. MALLOCH 247 



— Wing without distinct infuscation on cross-veins; third vein bare at ba e; 



hind tibia with one strong anterodorsal bristle; hind femur in both 



sexes with distinct bristles on posteroventral surface 63 



63. Tarsi black; hind femur with some moderately long strong bristles on 

 basal two-thirds of posteroventral surface; longest hairs on arista at 

 least as long as width of third antennal segment; interfrontalia not 

 interrujjted diruta Stein 



— Tarsi yellow; hind femur with fine bristles on almost the entire length of 



posteroventral surface; longest hairs on arista shorter than width of 

 third antennal segment; interfrontalia interrupted above middle. 



prisca Stein 

 Phaonia protuberans new species 



Male and Female. — Black, distinctly shining, with rather dense whitish 

 pruinescence. Thorax quadrivittate. Abdomen with a poorly defined sub- 

 triangular dorsocentral spot and lateral checkering on each tergite, black. 

 Legs black. Wings subhyaline, veins slightlj^ paler at bases. Calyptrae and 

 halteres yellow. 



Male. — Eyes rather densel}^ pale haired; narrowest part of frons about as 

 wide as third antennal segment; orbits with long setulose hairs below, which 

 become much shorter above and extend to anterior ocellus; profile as in figure 

 8. Thorax with two pairs of presutural acrostichals and four pairs of post- 

 sutural dorsocentrals; hypopleura with a few hairs on upper margin in front 

 of spiracle. Abdomen narrowly ovate, basal sternite bare, fifth with a broad 

 deep excision. Fore tibia unarmed at middle, the hairs on apical half of ven- 

 tral surface suberect but not very long; fore tarsus without long sensory hairs 

 on posteroventral margin of basal segment, moderately densely clothed with 

 short erect fine hairs; mid femur with about nine bristles on basal half on pos- 

 teroventral surfaces which are in an irregular series; mid tibia with three long 

 posterior bristles; hind femur with a series of anteroventral, and a few short 

 posteroventral bristles on basal half; hind tibia with two anterodorsal and two 

 anteroventral bristles, the anterior and posterior surfaces with the setulae 

 stronger than usual. 



Female. — Differs from the male in having the frons over one-third of the 

 head-width, the orbits laterad of the bristles with rather long setulose hairs, 

 the fore tibia with two posterior bristles, and the fore tarsus shorter. 



Length, 8 to 9 mm. 



Tijpe — male, Mt. Washington, Now Hampshire, alpine, 

 (G. Dimmock), [U. S. National :Muscum]. Allotype, female, Mt. 

 Washington, New Hampshire (Coll. Coquillett). Paratypes, 

 females, White ^Mountains, New Hampshire (^Morrison) ; Mt. 

 Washington, New Hampshire, August 16, 1916, 2500 feet (C. W. 

 Johnson); four males and one female, Mt. Marcy, New York, 

 above the 4800 feet level, July 21 and 27, on flowers of PotentiUa 

 tridentata and Arenaria groenlandica, (J. Bequaert). 



TRANS. AM. EXT. SOC. XLVIII. 



