337 



GENERIC CHARACTERS 



Larva. — Head elongate, tapering anteriorly, the portion anterior 

 to eyes distinctly longer than its greatest breadth; surface hairs long. 

 Segments of body well differentiated; each dorsal segment with 6 

 hairs in a transverse series beyond middle, the outer one on each side 

 very short, the middle one very long, and the inner shorter than the 

 latter but much longer than the outer ; lateral margin of each segment 

 with a pair of hairs, the anterior one very short, the posterior one very 

 long; hairs on apical segment long and equal, the segment rounded 

 posteriorly; ventral segments, excepting the apical one, each with 6 

 subequal hairs in a transverse series. 



Imago. — Antennae short, third joint disc-like; arista very short- 

 haired ; eyes large, with vertical color-bands, those of the female rather 

 widely separated, those of the male narrowly so. Thorax with de- 

 cumbent silvery pile ; scutellum with a posterior marginal ridge. Ab- 

 domen short, rounded, subglobose. Third vein of wing furcate. 



HABITS OF IvARVAE 



The larvae are found under bark of trees that has become slightly 

 loosened. They feed upon the sap and upon insect larvae and are 

 very sluggish. 



HABITS OF IMAGINES 



The flies frequent leaves of trees in the sunshine, and are very de- 

 liberate in their movements, walking slowly, but they take flight sud- 

 denly, though they fly rather heavily as compared with most members 

 of the subfamily. 



I know of no parasites of any stage in this genus. 



Key to Imagines 



1. Arista with very dense whitish pubescence which j?ives it the ap- 

 pearance of being thickened; third antenna! joint disc-like; 

 scutellum not regularly convex on disc, the center with a slight 

 hump ; pile on sides of mesonotum arranged in small punctiform 



groups punctifer. 



— Arista with very little pubescence, appearing filiform; third an- 

 tenal joint much higher than long; scutellum regularly convex 

 on disc; pile on sides of mesonotum arranged in irregular short 

 stripes liensJiawi. 



