Gillies. — Description of Trap-door Sjyicters' Nests. 301 



Art. XLII. — Description of Trap-door Spiders' Nests from California and from 

 Westerji Australia in the Christchurch Museum. By. R. Gillies, F.L.S. 



Plate XIII. 



[Read before the Otago Institute, 9th October, 1877.] 

 In November last, wlien in Christchurch, I had the opportunity, through 

 the kindness of Dr. Haast, of examining four trap-door spiders' nests from 

 CaHfornia and two from Western Australia, which are deposited in the 

 Canterbury Museum, and which I was informed have never been examined 

 or described. Each nest or trap-door has special features of its own which 

 I will point out afterwards, but there is a very marked distinction between 

 the Californian nests and the Western Australian, and between each of them 

 and our New Zealand species. The Californian nests have all thick doors 

 bevelled at the edge, and fitting tight into the mouth — the outside of the 

 trap-door being level and coincident with the surface around — they are, in 

 fact, true " cork nests." The South Australian ones have the mouths of the 

 nests raised above the surface around ; they are really on little hillocks or 

 protuberances of the ground and have the trap-door fitting on to the top of 

 the "mouth as a cap overlapping all round and raised in the centre like 

 miniature tea or coffee-pots with lids to them. A reference to my paper on 

 the New Zealand si^ecies * .will show that they are quite different from either 

 of these types. In that paper I stated that I was inclined to think the 

 distinctions laid down by Moggridge between cork nests and wafer nests 

 did not hold good so far as the Oamaru species is concerned. My examina- 

 tion of these nests has revealed to me that what Moggridge referred to as 

 cork nests was something quite different probably from what I understood. 

 The distinction between cork nests and wafer nests rests mainly on the 

 thickness of the door, and as he gives no measurements as a guide, I fell 

 into the mistake of thinking that the extremes of the thicknesses would be 

 within reasonable limits as compared with the size of the nest, and hence I 

 said that " doors of aU degrees of thickness are to be found and that this 

 distinction does not hold good." I find now that these Californian nests 

 have their doors so excessively thick in proportion to their size as at once 

 to justify the distinction of cork nests, and therefore that our New Zealand 

 species, with all their varying thicknesses of door, are all wafer nests. 

 These foreign nests, now about to be described, are also very much shorter 

 than those of our New Zealand species, and in this they approach more 

 nearly to the Jamaica nest in our own museum, and described at the end of 

 my paper mentioned above. It is believed that the ultimate classification 



* Trans. N.Z. Inst., Yni., Art. XXXI. 



