8o4 



THE POPULAR SCIENCE MONTHLY. 



silky matter. The doors are cut in a conical shape, to fit the flare 

 of the cylinder, and will not yield under pressure from without. 

 The exterior of the door is uneven and rough, like the ground 

 round it, whereby the attention of enemies is diverted. Inside it 

 is tapestried like the nest itself. The hinge, made of a compact 

 silk, possesses great resisting power, and such elasticity that the 

 trap infallibly falls back as soon as it ceases to be held up. The 





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Pig. 13.— Nest of one of the Trap Door Spiders (Moggridge). D, the door which closes nat- 

 urally by its own elasticity and weight; m, marks of the spider's claws when she has held it 

 down from inside. 



place of a lock or bolt is taken by a series of little holes, like 

 needle-pricks, arranged in a circle around the side of the door op- 

 posite the hinge. When the trap is down, the closing is so exact 

 that the most delicate instrument can not be introduced into the 

 interstice without danger of injury. If one tries to raise the trap, 

 the spider, clinging to the walls of the pit, and inserting its claws 

 into the holes of the cover, will make the most desperate efforts 

 to keep it shut. In the evening, the spider comes out stealthily 

 from its retreat, and goes to hunt its game in the fields. Having 

 finished its meal, it returns to its home, lifts the trap-door with 

 its claws, and disappears from view in an instant. 



A much larger and finer species of cteniza than the one just 



