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CHAPTER IV. 

 Orders of Insects, 



It has been shown already (see p. 4) that the class 

 Insecta is one of the four classes of Arthropoda. This is 

 divided into orders, each of which includes individuals 

 which have some prominent characteristic in common. 

 Each order is separated from all the others by the fact 

 that its members possess characters which are not shared 

 by the members of any other orders. 



The number of orders used in any classification may 

 vary according to the purpose for which it is intended. In 

 the present instance, for example, ten orders are considered ; 

 in a more careful analysis for systematic purposes, certain of 

 these might be divided to form others. Carpenter (Insects. 

 Their Structure and Life} employs fifteen orders, Comstock 

 (Manual for the Study of Insects) nineteen, and Sharp (Cam- 

 bridge Natural History, Insects, Yols. V, VI) carries out 

 the careful division until thirty-five orders are provided. 



When, as in the present case, only ten orders are used 

 in the classification, some of these must include groups 

 which differ slightly from the type of the order, but show 

 a decided relationship to it. 



Order I. Orthoptera. Straight-Winged Insects. 



This includes cockroaches, crickets, mole crickets, 

 grasshoppers, leaf insects, the godhorses, earwigs, and 

 similar insects. Insects of this order have two pairs 

 of net-veined wings, the first pair being thicker and 

 stronger than the second, while the latter are large and 



