242 



pairs of cruciate bristles ; the entire frons at vertex one third as wide 

 as head; the antennae sHghtly shorter; and the legs with the same 

 form and bristles as in the female of screna. In other respects the 

 specimen agrees so closely with the male that I consider it as almost 

 certainly belonging to the sam.e species. 



ADDENDUM 



After this paper went to press Mr. C. A. Hart and the writer succeeded in 

 oV)taining, at Miincie, 111., a large series of Palpomyia trivialis Loew, representing 

 both sexes. This species may be separated from P. stihasper Coquillett by the 

 bristling of the femora, the thorns being confined to the fore pair, and, in the 

 female, by the absence of the spines on the ventral surface of the last tarsal joint. 

 The male is very similar to that of subosper and may readily be confused with it, 

 as the thorns on the mid and hind femora are weak; but the claws are distinctly 

 smaller in trivialis, and there are no traces w^hatever of thorns except on the fore 

 femora. The last section of the costa in both sexes of trivialis is almost equal in 

 length to the distance from its apex to the apex of the upper branch of the media. 



