THE FOUR-WINGED GALL-FLIES. 543 
The outer side of the fourth and fifth joints of her antenna?, 
her knees, and a line on the outer edge of her shins, are 
white. Her feet are dull red. Her wings are clear and 
transparent, with a broad, smoky-brown, transverse band, 
beyond the middle of the first pair. Her body measures 
nearly six tenths of an inch in length. 
The dark-colored Oryssus is probably the same as one 
described by Mr. Westwood, in 1835, in the fifth volume* 
of “The Zoological Journal,” under the name of Oryssus 
Sayii, in honor of the late Mr. Say, who sent him the insect. 
It is of a deep black color, rough before and smooth behind, 
and is marked with white on the antennae and legs, like 
the red-tailed kind, with the addition of two short white 
lines on the forehead, between the lower corners of the 
eyes. The feet are black. The wings have a smoky band 
beyond the middle, which, however, fades away towards 
the inner margin. I have seen only females of this species, 
and they measure from four to five tenths of an inch in 
length. 
O 
It is possible that my Oryssus affinis, which is a male, 
may be the mate of the foregoing dark-colored species, from 
which it differs in having reddish feet, and in wanting the 
two white spots on the forehead. It measures four tenths 
of an inch in length. 
From this somewhat extended account, it is evident that 
we have very little power over the insects of the foregoing 
family. The most that we can do towards checking their 
ravages will be to destroy the females, whenever they are 
found laying their eggs. 
The four-winged gall-flies have very little outward resem- 
blance to the siiw-flics and horn-tailed wood-wasps. They 
agree with them, however, in boring into plants, and in 
laying their eggs therein. Vegetation does not often suffer 
much injury from their attacks, and it is only on account 
of the very singular productions, called galls, arising from 
* Page 440. 
