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 

 Lycosidae and are call- 

 ed the running spiders. 

 They live in burrows FlG 77 

 in the ground, coming 

 out to stalk and chase 



their prey. The eggs 

 are laid in globular 



- ^--.- 



The spinner- 

 ets of a spider, with 

 one spinneret enlarg- 

 ed to show the "spin- 

 ning spools "or tubes. (Much enlarged; after 

 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 misid&) (fi CT . 80) 

 burrows, one with door open, one with door i i i 



closed. (Natural size; from living spider in whlch IUn SldewiSC 



field,) or backward a swell 



