INSECTS AHACHNIDA DIAGRAM 6. 147 



CLASS ARACHNIDA. 



The class Araakiuda, winch at first sight seems greatly to 

 resemble that of insects, is nevertheless very easily distinguished 

 from it. While insects have six legs, 

 the Spiders, and all the animals 

 included with them in this class, have 

 eight legs. There are also other 

 differences,. The head and thorax are 

 united in such a manner that there is 

 no neck. The abdomen itself is some- 

 times joined to the head and thorax, as 

 in the mites ; and the body then forms 

 only a single ovoid mass with eight legs. Spider, back view. 

 The eyes are consequently placed on the corslet, the spider often 

 having six or eight, 

 or even twelve eyes, 

 separated from each 

 other, instead of being 

 united in a cluster 

 like those of insects. Side view O f Spider. 



The remainder of their structure much resembles that of insects ; 

 but they have not metamorphoses, but only moults. 



Many people are often much terrified at spiders, without 



