LIST OF ILLUSTRATIONS xi 



PLATE FACING PAGE 



IV. A Jumping Spider, Phidippus audax, and its Dragline 



a Preparing to leap 29 



b Leaping 29 



V. A Juvenile Jumping Spider, Phidippus, On A Thin 



Toothpick, Prepares To Fly 

 a Orienting in response to breeze, secured by 



dragline 52 



b Ballooning threads stream from spinnerets 52 



VI. Courtship and Mating In The Black Widows, La- 



trodectus mactans 53 



a The cautious approach of the small male 53 



b The mating 53 



VII. Black Widows, Latrodectus mactans 



a The male after mating is occasionally, as here, 



killed and eaten by the female 60 



b A female in her tangled snare with long-legged 



spiders, P silo chorus 60 



VIII. Relatives of Spiders 



a A desert solpugid (Eremobates) 61 



b A giant-tailed whip scorpion, Matigoproctus 



giganteus 61 



IX. Spider Relatives: Harvestmen on aphis-covered rose 



shoots 84 



X. Trap-Door Spider, Bothriocyrtum calif ornicum 



a Molting. Carapace and chelicerae freed FIG. 2 



b Molting. The shed skin FIG. 2 



c Cradle of eggs in burrow FIG. 2 



XI. California Trap-Door Spider, Bothriocyrtum call- 



jornicum 



a Exposed burrow 90 



b Male 90 



c Cork-door nest held open 90 



XII. California Trap-Door Spider, Bothriocyrtum cali- 



fornicum 



a Capturing a ground beetle 91 



b Lifting the cork lid 91 



XIII. Female purse web spider, Atypus bicolor 114 



XIV. A Western Trap-Door Spider, Aptostichus, Dorsal 



View of Male FIG. 3 



A Mexican Trap-Door Spider, Eucteniza 



