NET-WINGED INSECTS. 263 
tribe; for they catch their prey, which consists of Flies, 
Musquitoes, Butterflies, etc.,on the wing. They do this, 
however, with their claws, and not, like theSwallows, with 
their mouths. That they may readily see their prey as 
they fly about so swiftly m search of it, they have very 
large, compound eyes, as you see in Fig. 207, one of our 
common Dragon-flies, or Darning-needles, as they are 
often called. These formidable-looking insects are en- 
tirely harmless, never biting or stinging when we catch 
them. They are of great service to us in destroyimg the 
Musquitoes, of which they devour a great number. Some 
species are beautifully variegated in color. 
451. The eggs of these insects are deposited on the 
leaves of aquatic plants. The larve live wholly in the 
water. They have some very singular peculiarities. They 
have a kind of mask with which they can cover up their 
mandibles and most of the head. But this mask can be 
unfolded and extended, and, having on its end a pair of 
claws, it is used as an instrument for seizing their prey, 
as represented at Ain Fig.208. At B the insect is seen 
with the mask folded up. You see here, also, water is- 
suing from the end of the larva’s body. It is in this way 
that it propels itself through the water, just as a rocket 
