ARACHNIDANS. 



The Thysanoura, Parasita, and Aphaniptera. having no wings, 

 are frequently spoken of under the general name of Aptera, or 

 Apterous (i.e., wingless) insects. All the other Orders of insects 

 have wings, and are spoken of as " winged insects? 



FIG. 144. SPIDERS. 



CHAPTER XII. 



FOURTH CLASS OF ARTICULATED ANIMALS. 

 ARACHNIDANS.* 



THE Arachnidans, long confounded with the Insects, and 

 still commonly described as such, are distinguished from 

 the true members of the insect world by characters so conspicuous, 

 that the necessity for considering them as a distinct class must 

 be obvious to any one. 



In Insects, as we have seen above, the body presents three 



arachne, a spider. 



