The Structure and Habits of Spiders. 45 



The holes are sometimes nearly an inch in 

 diameter, and vary in depth from two or three 

 inches to a foot. The mouth is a little 

 enlarged, and closed by a thick cover that fits 

 tightly into it, like a cork into a bottle. The 

 cover is made of dirt fastened together with 

 threads, and is lined, like the tube, with silk, 

 and fastened by a thick hinge of silk at one side, 

 Fig. 22, B. When the cover is closed, it looks 

 exactly like the ground around it. The spider 

 holds on the inside of the door with the man- 

 dibles and the two front pairs of feet ; while 

 the third and fourth pairs of legs are pressed 

 out against the walls of the tube, and hold 

 the spider down so firmly, that it is impossible 

 to raise the cover without tearing it. 



Among the trap-door spiders of Southern 

 Europe, about which Mr. J. T. Moggridge has 

 written a very interesting book, are species 

 which make different kinds of nests. The 

 cover, instead of being thick, and wedged into 

 the top of the tube like a stopper, is thin, and 

 rests on the top of the hole, Fig. 22, C, and is 

 covered with leaves, moss, or whatever happens 

 to be lying about ; so that it is not easily seen. 



