CHAPTER VI 



THE SPIDER AND ITS ALLIES 



SPIDERS constitute a well-defined group called Araneina, 1 

 characterized by an unsegmented cephalothorax and abdo- 

 men, of which the latter is stalked, and bears spinning 

 tubercles or spinnerets upon its hinder end. Antennae 

 are absent. The first pair of mouth appendages are called 

 chelicerse and end in claws, at whose apices the poison- 

 glands open to the exterior. The second pair of mouth 

 parts, called pedipulps, are long, and seem to take the 

 place of antennae. Near the stalk of the abdomen on the 

 ventral side is a pair of slits which open into two lung 

 sacks (hence Dipneumones). In a few spiders there is a 

 second pair of slits ; these spiders have four lung sacs 

 (hence Tetrapneumones). 2 



The best known of our spiders are the orb web-spinning 

 garden spiders, belonging chiefly to the genera Epiera 3 

 or Argiope 4 and the house cobweb spinning spider 

 Theridium. 5 



Argiope spins webs of very geometric form between 

 stems of weeds, branches of shrubs, or along fences in 

 our meadows. 6 Its web belongs to the full-orb type in 



1 aranea, spider. 



2 A key to the seven subdivisions of the Araneina will be found at the 

 end of this Chapter, page 95. 



3 efjureipos, skilful, experienced. 



4 Name of a nymph. 6 0rjpl5iov, a little wild animal. 6 Fig. 78. 



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