State Agricultural Society. 
523 
of a distinct genus, of which genus itself is as yet the only known 
member. Occupying a position of such prominence, it becomes 
important to know the measure-worm from which this moth is pro¬ 
duced, wherefrom to acertain the characteristics of the caterpillar or 
larva state of this genus. I find this measure-worm to be of a peculiar 
type, differing prominently in its structure and other characters from 
all the larvae which are known in the genera related to it. It thus, 
equally with the perfect insect, justifies the separation of this species 
as a distinct genus. The singular habits of this worm, moreover, will 
render an account of it interesting alike to the general reader and 
the student in science. 
We meet with this measure-worm feeding upon the leaves of the 
lilac. But as it is a native insect of our continent and the lilac was 
introduced here from abroad, it will undoubtedly occur upon the 
ash or some other one or more of our indiginous trees or shrubs 
which are nearly related to the lilac. 
In the first period of their lives the small young worms are of a 
slender cylindrical form, and of a dark liver brown color, with shin¬ 
ing black heads, which are of the same thickness as the body. The 
mouth is white, and on the body are four white bands, which with a 
magnifying glass are found to be composed of short white lines placed 
upon the sutures side by side and lengthwise of the body. They 
have three pairs of legs placed upon the breast, a pair of thick pro¬ 
legs at the end of the body and a second pair a little forward of these 
last; and on each side of the back the three or four middle segments 
each show a small tooth-like protuberance projecting horizontally 
outward. 
The young worms eat small holes through the leaves, mostly along 
each side of the mid-vein. And when not engaged in feeding they 
all station themselves upon the underside of two or throe contiguous 
leaves, where, clinging with their hind feet, the hang downward iu 
a grotesque posture, having the middle of their bodies bent into a 
half circle with the two ends remaining straight. They continue for 
hours stiff and motionless in this position, hanging downward per¬ 
pendicularly, witli here and there one it may be, holding itself in 
an oblique direction. They do not feed upon rainy days, and then 
remain in this posture, fastened to the under surface of the leaves 
the whole day through. 
When they are grown to a larger size and have shed their skins 
they are considerably changed in their appearance. They are then 
of a sooty brown color with three very bright yellow spots on each 
