M. C. VAN DUZEE 87 



second: middle pair one and one-fourth times as long as their tibiae, hind 

 tarsi slightly thickened, about equal to their tibiae in length, first and second 

 joints of about equal length. Cah'pters, their cilia and the halteres, yellow. 



Wings gray; third and fourth veins ai)i)roaching each other from about the 

 middle of the last section of the fourth vein, but nearly jmrallcl at tips, fourth 

 ending in the apex of the wing; last section of fifth vein fully twice as long 

 as the cross-vein; anal angle rounded, the wing being rather abruptly nar- 

 rowed at its root. 



9 : Color, venation and form of the tarsi about as in the male. Face wide, 

 whitish; palpi black, large; antennae with the thiid joint somewhat triangular, 

 but little longer than wide; arista about as long as the height of the head, 

 slender. 



Descril)e(] from two males and one female, taken at Healy, 

 Alaska, June 24, 1921, Ijy J. M. Aldrich, for whom I am naming 

 this interesting species. Holuiij}K' and allotype in the United 

 States National IVluseum. 



TRANS. AM. ENT. SOC, XLVIII. 



