CHAPTER XII 

 SPIDERS AND OTHER ARACHNIDS 



Where Spiders Live. Spiders are considered " insects " by 

 many people, but they can be distinguished easily from them by 

 the presence of four pairs of legs instead of only three, and by 

 the union of the head and thorax into one piece, called the ceph- 

 alothorax. There are probably four or five hundred different 

 kinds of spiders living in the neighborhood of any city of the 

 United States. They are to be found in all sorts of places. 

 Many species live almost entirely around houses, making their 

 webs in the corners of the rooms, in the cellars, or outside in 

 window corners, crevices in walls, etc. Other species make 

 their homes under stones and sticks lying on the ground. Plants 

 of all kinds are alive with spiders, some preferring grass, and 

 others bushes or trees. 



Spiders with and without Webs. We always associate 

 spiders with spider webs, but a great many species which are 

 called hunting spiders do not build webs. They have nests, 

 but run about catching insects wherever they chance to find them 

 or lie in some place of concealment until insects come within 

 their reach. 



Types of Webs. The cobweb spiders build webs for catch- 

 ing insects, and live either in the web or in a nest close to it. 

 Cobwebs are of four principal kinds: 



1. The flat webs are closely woven of long threads crossed by 

 finer ones in all directions, and connected with a tubular nest 

 where the spider hides, and from which it runs out on the upper 

 side of the web after insects that may fall upon it. 



2. The netlike webs are made of smooth threads in large 

 meshes, sometimes in a flat or curved sheet held out by threads 



in 



