TRAP-DOOR SPIDERS. 65 



it with the greatest care. This beautiful lining is 

 yet further strengthened in particular parts, where 

 the nest is likely to be exposed to danger. But 

 the greatest amount of skill and care is bestowed 

 upon the trap door and its silken hinge. This 

 door is about the eighth of an inch thick, rough 

 on the outside, not much unlike an oyster shell, 

 which it also resembles in being thick and strong 



TRAP-DOOR SPIDER. 



near the hinge, but thinner towards the circum- 

 ference. The breadth of this hinge is various, 

 but sometimes it is very considerable, as shown in 

 the accompanying figure. It also possesses great 



