414 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



simply a rounded chamber underneath the surface and closed by a trap- 

 door, Fig. 352, which differs in no particular, as far as I can observe, from 

 the ordinary trapdoor of the American Cteniza californica. (See 

 7. Bur- Yig. 240 B, page 183.) 



y,°y ,!; It is difficult to say what may be the enemies of the Trapdoor 



Door spider against which such ingenious architecture has been reared 



and such vigilant watch is exercised. But the quite general testi- 

 mony is that these spiders leave their tubes at night and go forth in search 

 of prey; or, as in other cases, open the lids of their tunnels and spread strag- 

 gling lines near by, upon which passing insects are entangled and delayed 

 long enough to allow the spiders to pounce upon them from their open 

 caves. If we credit these accounts we might infer that the enemies wliich 

 the Trapdoor spiders most dread are not .such as are abroad at night. 

 Evidently the creatures are fearless at that time, a state of mind which 

 doubtless results from their knowledge that they are comparatively free 



from their worst enemies. The 

 enemies which they most dread 

 may therefore be reasonably look- 

 ed for among diurnal creatures, 

 and not among those of nocturnal 

 habits. 



Among these foes at least one 

 of the most formidable and irre- 

 sistible is a diurnal insect, the fe- 

 male of the terrible Digger wasp, 

 which I do not doubt will be 

 found to store Trapdoor spiders, 

 as well as Tarantulas and Lyco- 

 sids. There is no evidence known 

 to me that Pepsis formosa in- 

 vades the tunnel of the Myga- 

 lidiB in order to dig them out. 

 Such an act is not indeed be- 

 yond her powers, and, reasoning 

 from the conduct of Elis 4-notata, 

 it is highly pi-obable. But we are not yet warranted in attributing the 

 habit to her. Some lizard or mammal that might pull open the trap 

 with its claws may be looked for as also a probable enemy against which 

 Trapdoor spiders erect and defend their ingenious barrier. 



At all events, the spider herself is well aware of these enemies. Abbe 

 Sauvages invariably found, when he attemj^ted to open the door of the 

 nest of " the Mason spider " (Nemesia and Cteniza), that the mother was 

 on guard, holding down the lid of her tunnel with great force. In his 

 efforts to pull the trapdoor up the spider would jerk it down again, and 



I'"k:. 352. Trapdoor of t'teniza californica (natural size), 

 to show the claw marks on the silk lining. 



