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IN VEKTEBRATES. 



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Ephemerae, or Day-Flies. 



Tub Dbaqon-Fly. — There are twenty-one species, chiefly 

 distinguished by their color. The characters are the following: — 

 The mouth is furnished with jaws ; the fe,elers are shorter than the 

 breast; and the tail of the male terminates in a kind of hooked 

 forceps. All the species are provided with two very large and 

 reticulated eyes, covering the whole surface of the head. They 

 fly very swiftly, and prey while upon the wing, clearing the air 

 of innumerable little flies. Their voracious appetite, and the mul- 

 titude of lesser winged insects which, they destroy and devour, 

 fully entitle them to the name vulgarly, but correctly, given to 

 them, dragorirfly. In their own insect grade, they are indeed 

 dfaffoiis. In the months of August and September they are found 

 in our fields and gardens, especially near places where there are 

 stagnant waters. The eggs from which they are produced are 

 deposited in the waters, where they are hatched by the warmth 

 of the temperature, and from which they come fully formed and 

 provided with all their furious and voracious instincts. The great 

 ones usually live all their time about waters ; but the smaller among 



