156 THE INDUSTRIES OF ANIMALS. 



The Trap-door Spiders of the south of Europe 

 construct burrows which have been studied with great 

 care and in much detail by Moggridge.^ He found 



Fig. 20. 



that there were four chief types of burrow, shown in 

 the accompanying illustration (Fig 20) at about one- 



' J. T. Moggridge, Harvesting Ants and Trap-door Spiders, con- 

 tained in two elaboralely illustrated volumes, London, 1873-74. 



