86
THE ESSEX NATURALIST.
over the dorsal surface of the abdomen. When first disclosed
the pupa has a light yellow head, which darkens as the time for
emergence draws near. When about to pupate the larva
constructs a cell in the tree-bark, generally near the outer
surface; in this the pupa remains until just before the imago
emerges. It then bites its way out and crawls up the bark
to a suitable place for the emergence of the imago.
The perfect insects are to be found in large woods; their
flight is similar to that of the lace-wings, and like them they
fly at dusk. Their food consists of small insects and other
small animals; in captivity I have fed them on freshly killed
house-flies and on living aphids. I have never seen them
actually feeding, but the food vanished during the night, legs,
wings and all. I have not succeeded in breeding these insects
from the egg, but I believe they take two years, as some larvae
that are found in autumn are only half the size of others; the
number of moults that takes place is also uncertain, but some
specimens that I kept for over a year cast their skin three times.
It is not easy to keep the larvae under observation as they object
to the light; if bark is placed in their cage they
bite their way into it so as to become entirely hidden.
The eggs of the snake-fly are placed under the bark in a
cluster; they are cylindrical, slightly curved in their length,
and have a very characteristic knob at the micropolar end.
Some years ago I placed a male and female of Raphidia
maculicollis in a cage, with a portion of pine bark; food was
provided and eaten. They remained concealed during the
day time but were often seen walking about at night; at the end
of a week the male died, and later the female was seen thrusting
her ovipositor into all the fissures in the bark; she seemed to be
examining these places with the tip of the ovipositor. At one
place she stayed for some time with the ovipositor under a scale.
After she had died I examined this, and when the scale was
removed a cluster of eggs was found beneath it.
A detailed description of our four native species is to be found
in R. McLachlan's Monograph of the British Neuroptera Plani-
pennia. Trans. Entom. Soc, 1868. They can be distinguished
by the following characters:—
Raphidia notata, Fabr. The largest species. Head black,
with a reddish median smooth space extending from the hinder