SPIDERS 135 



victim. Then immediately the spider lets go the line with her 

 forelegs, and the released web springs back on the fly, thoroughly 

 entangling it in the fluffy meshes. If the victim is unusually 

 large and strong the spider will often spring her trap two or three 

 times to prevent it escaping. 



Another spider, Epeira basilica, constructs a dome-shaped web, 

 which strongly resembles an open umbrella ; under this, moreover, 

 she spreads a sheet of irregular threads, and above the dome she 

 weaves a mass of threads in the form of a pyramid. 



Sheet webs are the work of the Labyrinth Spiders (Agelenidce). 

 To this family belong the common, long-legged House Spiders, 

 which are responsible for the cobwebs that accumulate in out- 

 houses and disused rooms. The webs of an outdoor species are 

 often seen in numbers on the hedgerows and the banks of ditches 

 in country lanes. 



The Line-weavers, to which the greater number of British 

 spiders belong, weave a medley of fine lines, running in all direc- 

 tions among the grasses or over bushes ; and although of such 

 rudimentary construction, these webs effectively arrest and hold 

 many an insect that chances to fall into them. 



Some spiders, instead of weaving an open snare, make their 

 homes in cracks and crannies in walls or rocks, in which they 

 construct a closely woven tubular nest. Others are vagabonds, 

 roving about from place to place, and have no special place of 

 abode ; but there are very few species that have not some sort 

 of nest, or retreat of one kind or another. Many forms live in 

 burrows in the ground, and of these the most famous are the 

 Trap-door Spiders (Aviculariidce). ,., 



The Trap-door Spiders possess very strong jaws, and with 

 them they dig in the ground a hole several inches deep. The hole 

 is lined with a tube of silk, and the entrance is fitted with a door, 

 which may be either a thin, circular wafer of silk or a thick plug 

 like a cork, composed of alternate layers of silk and earth. The 

 door is attached to the mouth of the burrow by a hinge of silk, 

 and opens outwards ; so that when closed it is practically 

 impossible for an enemy to open it, particularly as the spider is 

 in the habit of clinging to the inside of the door with her legs and 

 firmly holding it down when she is alarmed. 



Several other ingenious forms of nest are constructed^by 



