NEW MUSCOID FLIES FROM THE ANDEAN MONTANYA 95 



vittae. Apex of scutellum faintly reddish-yellow. Besides the marginal 

 macrochaetae mentioned in the generic description the scutellum has four 

 pairs of erect spinelike macrochaetae, one pair in middle with a group of 

 three or four on each side. First abdominal segment has a bunch of 

 spines at side, but the rest of margin above is bare. The median spine- 

 pectination of hind margin of second and third segments consists in each 

 case of four pairs successively increasing in length outward from the me- 

 dian pair which is shortest, with three successively shortened pairs outside 

 these on second segment and only two such pairs on third segment. The 

 whole venter is shining brown to blackish, with bunches of spines on 

 median line. The whole tergum is subshining soft black, with deep 

 golden-yellow poUinose marking covering whole dorsum of anal segment 

 except the rounded subtuberculate and slightly separated buttocks, which 

 each bear a bunch of a dozen or so spines. Legs are evenly rust-yellow, 

 wdth tarsi wholly light yellow. Wings evenly infuscated throughout, teg- 

 ulae wholly water-white to white. Halteres pale brownish ; hypopygium 

 light brown. 



Signosomopsis, new genus. 



Differs from Signosoma as follows : Description drawn from both sexes. 

 Abdomen still more narrowed apically, only faintly emarginate and equally 

 so in both sexes, not buttockslike. Hind margins of first three abdominal 

 segments above almost evenly subarcuate and without any impressed 

 effect, except that the margin of first segment is flattened in middle. Sec- 

 ond and third abdominal segments with sparse marginal row of macro- 

 chaetae, that of third segment double on sides ; both segments with disced 

 macrochaetae in an irregular more or less double median transverse row, 

 the row of third segment longer. The two lateral marginal scutellar 

 macrochaetae more separated, the posterior suberect pair hardly heavier 

 than these and removed from margin, with a shorter erect pair between 

 them and a very weak apical pair of bristles either decussate or not decus- 

 sate behind latter ; the discal spinelike macrochaetae of scutellum are not 

 quite so strong. Three sternopleural and three postsutural bristles ; two 

 acrostichal bristles both before and behind suture. 



Palpi represented by bristlets. Second antennal joint strongly elongate, 

 the third but little longer than second. Male front at vertex noticeably 

 less than eye-width, female front at vertex about equaJ to eye-wddth. 

 Two outer proclinate orbited bristles in female. 



