TRAP-DOOR SPIDERS. 83 



substance, the li^lit being clearly seen through each 

 hole. I do not think, as I have somewhere seen 

 suggested, that they are intended to afford a hold for 

 the spider's claws when she would keep her door shut 

 against the efforts of an enemy, for what would be 

 the use of having them in the tube close to the lid, so 

 close that not the eighth of an inch intervenes between 

 the surface of the lid and that of the tube, when the 

 former is tightly closed ? I would suggest whether 

 they may not be air-holes, for so tight is the fitting 

 of the lid, and so compact the texture of the material, 

 that I should suppose the interior would be imper- 

 meable to air but for this contrivance."* " The spider 

 that inhabits this nest is black, with the thorax of an 

 exceedingly lustrous polish, its abdomen is full and 

 round, its legs very short." 



Another form of this single door wafer nest is de- 

 scribed by j\Ir. Sells,! in wdiich there is a hinge-like 

 thickening of the silk lining of the tube about an inch 

 below the actual hinge of the door, which it is sug- 

 gested may serve to give additional elasticity. This 

 was not found, however, in all the nests examined, 

 and Mr. Sells conjectures that in newly constructed 

 nests the lid may close sufficiently firmly without 

 this contrivance, and that it is only added in older 

 nests. 



Patrick Browne's figure, to which reference has been 

 made above, represents a nest with two doors, one 

 applied against the other, at the mouth of the tube. 



* I cannot myself think this explanation probable, and should still be 

 inclined to consider these punctures to be the claw marks of the spider, as is 

 the case in some European nests. 



t ]Mr. W. Sells. Notes respecting the Nest of Cteniza nididans, in Trans. 

 Ent. Soc. ii. 207-210. 



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