8 RECORDS OF THE AUSTRALIAN MUSEUM. 



sometimes flaccid. The nests of some species are provided with 

 a second, inner lid of a very special nature. 



There are in the collection of the Australian Museum some 

 nests from the Tweed River, New South Wales, and from 

 Queensland. In one, from Mirwillumbar, Tweed River, the 

 walls have been carried considerably above the surface, and 

 built so as to incline forward, so that whilst the front eleva- 

 tion measures only three-quarters of an inch, the hinder 

 measures one and a half. The outer walls are covered with a 

 scale moss, determined by my colleague, Mr. T. Whitelegge, as 

 one of the Hepaticse ; the interior is beautifully lined with silk. 

 The lid is thick and heavy, truncate behind, where it is attached 

 by a long hinge ; the sides and front are round ; it is concave 

 without and convex below, and has its exterior also clothed with 

 the Hepatic moss. Others, from the same district, and from 

 Queensland, agree with the above in every detail, except that the 

 lids were flush with the ground. As no Spiders were sent with 

 the nests, it is impossible to assign them with certainty to any 

 species or genus. They probably belong to the Ctenizinpe. 



The Spiders allied to Arbanitis, exhibit great diversity in the 

 construction of their terrestrial abodes. In some instances the 

 nest is simple and cylindrical, sometimes branched, and not in- 

 frequently complicated. The lid is also variable, being, according 

 to the species, either of the " cork " or " wafer " type, unequal in 

 circumference, rigid or flaccid. In some cases the Spider con- 

 structs an interior door of a very different nature to the external 

 one. This occurs where the nest is branched, and is employed to 

 shut off" communication with the main chamber. It is attached 

 to the wall by a strong silky tissue, inclining or sloping to one 

 side, and provided at its extremity with a little fringe of silk. It 

 sometimes happens that predatory foes invade these subterranean 

 dwellings; the invader is usually of a powerful and aggressive 

 type, and one with which it would be difficult or dangerous to 

 contend. The second chamber, with its door, affords a safe retreat. 

 Immediately upon the approach of danger, the Spider passes into 

 the supplementary chamber, closes the door, and by placing its 

 body securely against it, resists pressure from without. The 

 intruder, not suspecting the existence of a second chamber, and 

 finding the main one empty, retires. Moggridge spent the declin- 

 ing years of an invalid life at Mentone, in the South of France, 

 studying the habits of these interesting Arachnids." 



Gillies has described and figured some New Zealand trap-door 

 nests,^" and these doubtless belong to this group. In some instances 

 the nests were almost vertical, being nearly straight in outline ; 



11 Moggridge — Harvesting Ants and Trap-door Spiders, London, 1873. 



12 Trans. N.Z. Inst., viii., 1875, p. 222, et seq., pis. vi.-viii. 



