254 THE ENTOMOLOGIST. 
margin of the anterior segment and the borders of the 
spiracles yellowish. The thoracic legs were yellow, with 
brown claws, and had a black mark on the last joint. The 
folds at the side were slightly hirsute. There were six pairs 
of abdominal legs, yellow, with a small transverse black line 
on the outside. The anal valve was brownish black, having 
a small spine on either side (fig. 4). Lastly, the ventral 
surface of the last segment and the two anal legs were deep 
yellow. These larvae, which fed on the birch, were of a 
restless nature, frequently raising the abdomen and curving it 
over the back, in which position they would remain for some 
time. Hardly had the colony returned to a state of rest, and 
each individual assumed a natural position, when one of the 
number became restless, and commenced waving about from 
side to side, its example being followed by all the others, and 
some time elapsed before there was another pause. In their 
restless habit, as well as in their gregarious mode of living, 
they more nearly resembled Septentrionalis than Varus. On 
the apodal 4th segment, and on the 5th and 6th, between the 
legs, were greenish gray dermal processes, which could be 
reverted like the horns of the snail: these organs (fig. 5), which 
could be protruded to three times the length of the legs, were 
open at the extremity, whence a viscid and fetid fluid could 
be ejected. We have already observed similar glandular 
openings in nearly allied species. 
In the beginning of October the larve took to the earth, 
and buried themselves as deeply as they could in the jar: the 
cocoon, which was single, was black and tough, very smooth 
within, and rough exteriorly, and curled up; in these the 
‘ Jarve passed the winter. They passed into the pupa state at 
the end of April, being probably at first white and afterwards 
coloured. On the 5th of May of this year I found one which 
had already acquired its full colouring; of this I made a 
drawing (fig. 7), which calls for no special remark, excepting 
that the insect in question had so nearly reached the time for 
shedding the thin pupal membrane that the antenne were no 
longer lying along in front of or between the legs, but were 
being moved about; in fact, the first imago, a female, 
appeared on the 4th of May, and was soon followed by 
others; a male appeared later. The female (fig. 8) had the 
head, thorax and antenne black; palpi gray; cenchri white; 
