THE EUROPEAN PINE SAW-FLIES. 521 
thorax ; her body beneath and her legs are paler, of a 
dirty leather-yellow color ; and her wings resemble those 
of the male. Her antennas are short, taper to a point, 
consist of nineteen joints, and are toothed on one side like 
a saw. My specimens of this kind of saw-fly, which were 
raised from the caterpillars in the summer of 1838, came 
out of their cocoons towards the end of July in the same 
year ; hut I have also found them on pines and firs early 
in May. 
The European pine saw-flies lay their eggs in slits which 
they make with their saws in the edges of the leaves ; and 
it is probable that our fir saw-flies proceed in the same way. 
In June and July the false caterpillars of the latter may 
be found on firs ; and, according to notes made by me 
many years ago, the same insects, or some very much like 
them, were observed on the leaves of the pitch-pine also. 
They are social in their habits, living together in consid- 
erable swarms, and so thick that sometimes two may be 
seen feeding together on the same leaf, and sitting opposite 
to each other. In order to lay hold of the leaf more firmly, 
they curl the hinder part of the body around it ; and, if 
they are disturbed, they throw up their heads and tails 
with a jerking motion. When fully grown, they are from 
five to six tenths of an inch in length ; they are nearly 
cylindrical in form, thickest before the middle, and tapering 
behind, and have twenty-two legs. The head and the first 
three pairs of legs are black. The body is of a pale and 
dirty green color above, with a light stripe along the top 
of the back, separating two of a darker-green color ; there 
are two dark green stripes on each side of the body ; and 
the belly and prop-legs are yellowish. When young, the 
two stripes on the back are much darker, and those on 
the sides are nearly black. The skin, though covered with 
very fine transverse wrinkles, is not rough, and with a 
magnifying-glass a few short hairs may be seen scattered 
over it. After the last moulting their color fades, and they 
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