CHAPTER VI. 
Order Odonata (Od-o-na'ta). 
The Drago?i-Jlies a?id the Damsel-flies. 
The members of this order have four membranous wings , 
which are finely ?ietted with veins ; the hind wings are as large 
or larger than the fore wings; and each wing has near the 
middle of the front margin a joint-like structure , the nodus. 
The mouth-parts are formed for biting . The metamorphosis 
is incomplete . 
The name of this order is evidently from the Greek 
word odouSy a tooth ; but the reason for applying it to 
these insects is obscure. 
The Odonata are easily recognized by the form of their 
wings, which are long and narrow; and possess near the 
middle of the front margin of each a little notch and a 
strong cross-vein. This structure resembles in appearance 
a joint, and is consequently named the nodus . 
The mouth-parts are fitted for biting, these insects be¬ 
ing carnivorous and voracious feeders in the adult state. 
Both the upper lip and the lower lip are large, and the 
two nearly enclose the jaws when at rest. 
The nymphs are all aquatic, and can be easily recog¬ 
nized by the form of the labium, which is long and jointed, 
and when extended reaches far out; it is armed with pow¬ 
erful hooks with which to seize their prey. The terminal 
portion is broad ; and when the lip is folded back in the 
position of rest, it presents an appearance which has sug¬ 
gested for it the term mask. 
Sg 
