CHAPTER VI. 



Order Odonata (Od-o-na'ta). 



The Dragon-flics and the Damsel-flics. 



The members of this order have four membranous wings, 

 which are finely netted 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 odous, 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 fiodus. 



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. 



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