SPIDERS AND OTHER ARACHNIDS 



117 



diving bell, which it anchors by threads to water plants, and fills 

 with air in the aforesaid manner. Thus the animal lives in air 

 in the midst of the water! (Schmeil). 



Trapdoor Spider. - - The nests of the trapdoor spider, often 

 seen in collections of curios, usually come from California. The 

 spider which makes the nest is blackish brown in color and meas- 

 ures a little over an inch in length. A cylindrical tunnel is dug 

 in the ground, the walls of which are made firm by gluelike 



A, tarantula ; B, trapdoor spider. (From Coleman.) 



saliva, and then lined with silk (Fig. 63, B). The entrance to 

 this tunnel is covered by a hinged door. From this place of con- 

 cealment the spider ventures out after its prey, returning at the 

 first sign of danger. The top of the door resembles the surround- 

 ing earth, so that the nests are hard to find. If the spider is dis- 

 covered, it holds the door shut from within and is dislodged with 

 difficulty. 



Tarantulas. -- Certain large, hairy spiders that live in w T arm 

 parts of the world are commonly called tarantulas (Fig. 63, A). 

 These spiders are supposed to be very poisonous, but most of 

 the stories told about them are not true, since they very seldom 

 bite, and if they do, the injury is probably no worse than the sting 

 of a bee. 



