ARTHROPODS AND MOLLUSCS 



167 



are lined with silk, and which in the case of the trap- 

 door spider are covered with a door or lid made 

 of silk and soil. The top of this door is always covered 

 with soil or bits of leaves or twigs so that it is nearly indis- 

 tinguishable from the surface of the ground about it. 



The common rather large swift black spiders found under 

 stones and boards are 

 hunting spiders, be- 

 longing to the family 

 Lycosidse and are call- 

 ed the running spiders. 

 They live in burrows pio. 77. The spinner- 



in the ground, coming ets of a spider, with 



out to stalk and chase °f spinneret enkrg- 

 . , ed to show the spm- 



tneir prey. ine eggs ning spools" or tubes. (Much enlarged; after 



are laid in globular Jenkins and Kellogg ) 



egg-sacs which are 

 often carried about, 

 attached to the 

 spinnerets, by the 

 female (fig. 79). 

 The young spider- 

 lings after hatch- 

 ing, in some species, 

 climb on to the 

 mother's back and 

 are carried by her 

 for some time. 

 Other kinds of 

 wandering or hunt- 

 ing spiders are the 

 crab-spiders (Tho- 



FiG. 78. Trap-door spider (California), and two misidse) (fig. 80), 

 burrows, one with door open one with door \^^.^ ^y j^^ 



closed. (Natural size; from living spider m 



field,) or backward as well 



