14 INSECUTOR INSCITI/E MENSTRUUS 



frontals, the latter numbering only four pairs. TTiree strong proclinate 

 outer orbital bristles. A weak strongly divergent pair of ocellar bristles 

 inclined slightly forward. Inner vertical bristles about same strength as 

 inner orbitals. Lowest fronted bristle nearly as low as end of second an- 

 tenneJ joint, latter elongate and rather more than half as long as third 

 joint; arista microscopiccJly pubescent, thickened on about based third, 

 basal joints short. PeJpi well developed, thickened on apical half ; pro- 

 boscis short and fleshy. 



Three sternopleurcJ and three postsutural bristles. Scutellum with two 

 strong latercil pairs of bristles, a strong decussate subapical pair, a short 

 erect straight pair between last, and no discal. First abdominal segment 

 with latereJ marginal and disced but no median macrochaetae ; second seg- 

 ment with lateral marginal and median subdiscal but no median marginal ; 

 third segment with marginal row of about four on each side but none in 

 middle, the median margined represented only by a strong discal or sub- 

 discal pair ; anal segment wath marginal and subdisced rows, and a strong 

 median discal pair. All the tibiae spined, spines of middle tibiae very 

 strong. Claws of femede not longer than last tarsal joint. Apiced cell 

 open, ending well before wingtip but rather nearer to same than to end 

 of second vein. Fourth vein continued in short stump, apical crossvein 

 gently bowed in ; hind crossvein sinuate, about parallel with hind wing- 

 margin, distinctly nearer to apiced crossvein than to small crossvein. First 

 vein bristly to tip, third bristly to end of second vein, fifth bristly hedfway 

 to hind crossvein. Costal spine almost atrophied. 



Reproductive habit, larviposition of white maggots on or near host. 



Type, Xenoplagia setosa, new species. 



Xenoplagia setosa, new species. 



Length of body, 8.5 mm. ; of wing, 6 mm. One female taken on 

 flowers of Philibertella fiava, Canada de Semian, tributary to vedley of 

 Rio Chira in northwestern Peru, February 14, 1912. 



Entire front, including frontalia and ocellar triangle as well as upper 

 orbits, pede golden or breissy pollinose, the frontalia only faintly differen- 

 tiated in color in some views. Whole face, including parafacieds, cheeks, 

 and lower orbits, silvery. Antennae blackish, the tips of first and second 

 joints pede. Palpi reddish-yellow. Occiput silvery-cinereous, with sparse 

 short grayish pile. Pleurae silvery ; thoracic dorsum silvery wath a faint 

 brassy tinge, the usual four vittae narrow and rather delicate. Abdomen 



