THE ORDERS OF THE HEX A POD A. 47 



I. II. 



III. ORTHOPTERA. | DERMAPTERA. (Forficulida) 



( ORTHOPTERA. 



IV. PHVSOPODA. PHYSOPODA. 



V. HEMIPTEKA. \ HOMOPTERA. 



f HETEROPTERA. 



fNEUROPTERA. (Siatidce, Hemerobida^ 

 VI. NEUROPTERA. \ MECAPTERA. (Panorpida.) 



[ TRICHOPTERA. {Phryganeida) 

 VII. LEPIDOPTERA. LEPIDOPTERA. 



V,,,.D,PT ER A. 



f 



IX. COLEOPTERA. \ ACHREIOPTERA. 



I COLEOPTERA. 



X. IlYMKNOPTERA. HYMENOPTERA. 



It is not my purpose in this place to discuss the distinguishing 

 features of the orders of insects. But it seems worth while to 

 present here a brief tabular statement of the more important ordinal 

 characters. This table will aid the student in formulating his ideas 



:o the characters of the orders and as to the relations of the 

 orders to each other. It should be borne in mind, however, that a 

 linear arrangement is not a natural one ; it is simply a necessity of 

 book-making. The arrangement adopted here is the one that I be- 

 lieve best indicates the relative rank of the various orders take 

 a wh 



e is no doubt that the Thysanura is the lowest of the orders. But the 

 position assigned to any one of the other orders is open to dispute. Thu 

 find in the Orthopt^ra certain forms (the earwigs) which show as strong affini- 

 ties to the Thysanura as do any of the Pseudoneuroptera. And some entomol- 

 ogists hold that the Physopoda is tin- lowest of the orders of winged 



To enter into a detailed discussion of the reasons which have led me to 

 adopt the sequence of the orders given in th< following pages would be beyond 

 cope of this work; but the following generalizations will indicate the 

 more important ones. 



That series of orders in which the insects undergo an incomplete 

 phosis (the Amctabold) is undoubted!, an tli.it (tin- .\ff/<iM<i\ 



the trans- i is a completr iic chief objection to pla< 



series as a whole above the former is the wide separation thus brought about 

 between the Neuroptcra and Pseudoneuroptera. I have felt, how< 

 this was the least of two evils. Within the lower scries t 

 which the mouth-parts are formed for biting are placed lower on 

 than the two orders in which the mouth is more highly modified. Of these 



