Gitires.—On the Habits of the Trap-door Spider. 229 
any one just bore an inch augur-hole a foot into the ground, and cover it, to 
prevent the actual beating of the rain on the mouth, and see how long the 
hole will remain perfect, or free from water, even in a very ordinary season. 
It must be borne in mind, too, that almost always the mouth of each hole 
is on flat ground, even though it may be on the face of a terrace, and though 
I have watched narrowly to detect if there were anything in the configura- 
tion of the ground, or in the spots selected, that might act in the way of 
turning off surface water from the mouth of the nest, I never could detect. 
any; on the contrary, instances were not unfrequent where the actual sur- 
roundings of the mouth of the nest made it a matter of certainty that, 
during heavy rain, the surface drainage would be directed towards the nest, 
and would lodge there. An instance of this, on a small scale, is seen in 
one case, where the depressed mouth of the nest was underneath the drip 
from the stable-roof. As to the other necessity alluded to above, that of 
the spider existing for some considerable time with very little air, it will be 
seen further on that I have repeatedly found the living spider in its nest 
with the trap-door sealed up and plastered over with clay on the outside, 
and specimens of the lids so sealed up are now before you, and with no 
other visibile means of ingress or egress. This, 1 think, indicates the same 
thing—that the spider can exist with a very small supply of air. 
Aspect of the situations where found. 
With regard to the general situation of the nests. Those found 
in the Woolshed Fence, as represented in Sketch No. 9, Plate VIIL., 
were always found on the southern or shady side of the sod wall. 
But it must be remembered that a sod wall gets heated up very 
much with the sun’s rays, and is peculiarly dry and warm. In the 
sketch a nest is drawn on each side, but this is to show the two styles 
of mouth without drawing another fence. In all the other situations, where 
I have observed them, the nests are always on northern or sunny slopes 
of greater or less steepness, never in stony or rocky ground, and never 
actually in the face of a bank so as to be the cause of the trap-door shutting 
to by its own weight, but always each nest on a little bit of flat, or almost 
flat, ground. So much is this the case that, even in the sod wall (Sketch 
No. 9, Plate VIII.) the nest is not tunnelled in at right angles to the slope 
of the wall, and the trap-door does not hang at the angle of the wall, but a 
little platform is excavated flat, or nearly so, out of the wall, and on this 
flat the nest is excavated vertically at first. These may appear to you 
minute distinctions; but they are such as distinguish the Otago species 
from those found elsewhere, for Moggridge, writing of the Mediterranean 
__« All these Trap-door Spiders seem usually to pre- 
species, says (page 88) or loose terrace walls 
: 
fer rather moist and shady places and sloping banks, 
