LIBRARY

ODONATA 231
pound eyes. The antenme are very short, inconspicuous, and awl-shaped with
from three to seven segments. The mouth parts are well developed for a predatory
life. The mandibles are strong and sharply toothed, the maxil1re have
unsegmented palpi and toothed and spined maIre, the submentum has a cleft
ligula or median lobe and two-segmented labial palpi - the first segment in
the form of a lateral lobe and the second as a movable hook. The palpigers or
I - ___ mentum
'I /submenlum movable hook ..•.
Nymph
,/ -·.antenna
labium
labium
FIG. 81. The naiad of a dragonfly showing important characters and the mouth parts drawn
separately.
side pieces are called squames or squamre. The thorax is obliquely segmented
so as to force the dorsal regions backwards and the ventral regions forwards,
thus placing the legs near the head where they are especially useful as a basket
for scooping up living prey captured on the wing. The legs are short and
adapted only for perching. In some males the tibire are dilated. The threesegmented
tarsi terminate in a pair of toothed claws between which there is a
rudimentary empodium called the plantula. The wings are attached by means
of a single axillary and are vibrated directly by the powerful thoracic muscles.
The position of the wings in repose and some of tlle more important types of