TRAP-JDOOn SPIDERS. 225 



wards to tlie hinge, which is always placed afc the 

 point of bifurcation of the tubes, and having two 

 crowns separated from each other by the gusset-like 

 web of silk which connects the door on either side 

 with the lining of the main tube, one of these crowns 

 fitting into and closing the main tube, while the other 

 fits into the aperture of the branch. 



The wedge-shaped structure of the door is seen in 

 its most exaggerated form in the nests of the younger 

 spiders (figs. B, B 1, Plate XVIII.), and becomes less 

 so in the older and larger ones (figs. Al, A2). I 

 have even seen some of these lower doors, evidently 

 made by old spiders, which were so much flattened as to 

 bear a considerable resemblance to that of N. Eleanora. 



The main tube of the nest is from 10 to 12 inches 

 long, and usually enters the earth almost horizontally, 

 bending downwards from the point at which the 

 branch joins it, and where the lower door is hung. 

 This causes the lower door to lie nearly horizontally 

 when not in use, and its lower crown probably serves, 

 by fitting into the aperture of the branch, to sustain 

 it in this position and prevent it from falling forward. 

 The point of bifurcation is placed, as a rule, much 

 nearer to the entrance of the nest, than it is in the 

 two other branched nests, and occurs usually within 

 two inches of the surface of the earth ; so close is it 

 indeed that, on lifting the upper door and looking in, 

 one may frequently see the lower door move across 

 and close the passage down the main tube, pushed by 

 the spider from below. This frequently enabled me 

 to secure the spider without having to follow her to 

 the bottom of the nest ; and, when fortune favoured 

 me, I secured a block of earth by one rapid sweep of 



