NO. 2115. NEW NEOTROPICAL MUSCOID FLIES— TOWNSEND. 417 



MINTHOPSIS, new genus. 



Genotype. — Minthopsis vittata, new species. 



Differs from Mintho as follows: 



Female. — Parafacials with microscopic hairs. Cheeks two-fifths 

 eye-height or rather more. Vibrissae decussate on extreme tips, in- 

 serted well above oral margin. Second antennal joint elongate, the 

 third joint only three or at most four times as long as second. Faciaha 

 ciliate. Arista nearly bare, thickened hardly over one-third way, 

 second joint hardly twice as long as wide. Ocellar bristles present. 

 Frontals descending lower. Front much wider than one eye; 

 frontaha very broad, nearly or quite equilateral. Eyes distinctly and 

 rather thickly short-hairy. Head scarcely wider than thorax. Two 

 sternopleural bristles only. No discal macrochaetae on intermediate 

 abdominal segments; no median on segment one, a lateral on seg- 

 ments one to three, median marginal pair on two and three, discal 

 and marginal on anal segment. Abdomen short. Front tarsi moder- 

 ately swollen subcyhndric, not so flattened laterally; all metatarsi 

 very long; all claws short, the front ones modified. Apical cell closed 

 distinctly before wingtip. Cubitus rounded, without stump or wrinkle. 

 Hind crossvein nearer to cubitus than to small crossvein. 



Male. — Differing from the female as follows: Second antennal 

 joint very short; third very long, reaching vibrissae, about six or 

 seven times as long as second. Arista subgeniculate, thickened fuUy 

 halfway or more; second joint very long, about four times as long as 

 wide. Faciaha not so strongly cihate. Eyes almost bare, with only 

 very sparse hairs, mostly above and almost imperceptible. Para- 

 frontals narrower, but frontalia about same width. Parafacials nar- 

 rower, appearing more elongate. Vibrissae nearer to oral margin, 

 weaker, barely or not decussate. Frontals not descending so low, 

 weaker. Three sternopleural bristles, the third being below the front 

 one of the other two. Cheeks hardly one-third eye-height. Middle 

 metatarsi longer than others. Claws all short, the front ones normal; 

 tarsi all slender. Abdomen and whole body much narrowed, in- 

 cluding head. A median marginal pair of macrochaetae and one 

 lateral on segments one to four. Apical cell closed in wingtip. Hind 

 crossvein in middle between cubitus and small crossvein. 



This is probably one of the most notable cases of sexual differentia- 

 tion in the superfamily, so far as characters that are ordinarily of 

 generic value are involved. 



MINTHOPSIS VITTATA, new species. 



Length of body, 5 to 6.5 mm.; of wing, 4 to 6 mm. Four females 

 and two males, Huariaca, Peru, high montanya of the Rio Huallaga 

 canyon, about 10,750 feet, December 20 and 21, 1913, on foliage 

 (Townsend) . 



§1022°— Proc.N.M.vol.49— 15 27 



