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B. MYRIAPODA (Centipedes and Millepedes). These 

 animals have their head distinct and the rest of the 

 body divided into a series of rings ; they have 

 always organs of locomotion (legs) on all the 

 segments. In the beneficial Centipedes, one pair to 

 each segment ; in the injurious Millepedes, two 

 pairs to all the segments except the first three. 



C. ARACHNOIDEA (Spiders, Mites, &c.) These have 

 the head and thorax united (Spiders) or the head 

 distinct from the more or less fused thorax and 

 abdomen (Ticks and Red Spiders). They have four 

 pairs of legs attached to the lower surface of the 

 thorax, except the Gall Mites (Eriophyes), such as 

 the Big Bud Mite of Currants, in which there are 

 only two pairs. 



D. HexAPODA (True Insects). These have six legs 

 attached to the thorax never eight, and none on 

 the abdomen. They breathe by means of air tubes 

 or trachea. 



The creatures dealt with in this book are all six- 

 legged or hexapod animals, what we popularly call 

 Insects." 



STRUCTURE OF A TYPICAL, INSECT. 



A grasshopper will serve as the best example to 

 study the structure of a typical insect. We can at once 

 see that the body or trunk is divided into three portions 

 called (i) head, (2) thorax, (3) abdomen. The head bears 

 the following structures antennae, two kinds of eyes 

 and the mouth. 



A note on the Red Spider is also included. 



