1923] 
Studies in Asilidce (Diptera) 
219 
as by the maculation of the abdomen. In Coquillett’s key (page 
385, Back monograph, 1909) it goes to the last couplet, but does 
not conform with either argentatus or (Emulator. The recently des- 
cribed N. utahensis Banks likewise goes to the last couplet of 
the key but differs from the present species in weaker chsetotaxy, 
blacker thorax, and, apparently, much smaller size. 
