74 THE AUSTRALIAN NATURALIST. 
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the extremity of same, and hence there is always a brown cir- 
cular patch or ring to be found (marking what might be termed 
the “high-water” mark of the fluid), and thus a line of least 
resistance is formed at which, naturally, the apex comes off in 
lid-like fashion at the emerging of the moth. 
Finally the larva—now a wrinkled object and reduced to 
half its size—makes its way head first till it reaches the apex 
where it remains in readiness to pupate. Truly a wonderful il- 
lustration of instinct. 
Of the three larvae (Doratifera) under observation, two at-' 
tached themselves to the lid of a box and neck of a bottle re- 
spectively, but the third chose the twig of a brush-box tree, and 
before commencing to spin, bit away one-third of an inch of the 
bark and into the wood, thus doubling the time taken by the 
others. Of eight cocoons I have taken from trees, all have 
been attached in manner described, evidently for the purpose of 
fitting the cocoon into a groove and hence strengthening its 
foundation. 
In addition to several trees in the bush, I have seen these 
larvae in considerable numbers on guava and apricot trees, hence 
it is evident that they acquire tastes with facility, and, unless 
checked, may prove yet another pest in the orchard. 
A FEW OBSERVATIONS ON TRAP-DOOR SPIDERS. 
By Ross M. Winter. 
These observations on the common brown Trap-Door Spider 
were made during the past two weeks to 6th March, 1922. The 
spider’s holes occur in a “chip” tennis court at North Sydney. 
In the forenoon of a hot day the holes all seemed to have 
the doors beside them, and in most cases the spiders were lurk- 
ing just inside the top of the hole. Passing the hole simply 
made the spiders hastily retire into the darkness, but pounding 
the earth a few yards from the hole with a mallet made them 
put the trap-doors over the entrance.. The method of putting 
on the door is as follows:—The door (or lid) lies just beside 
the hole with the underneath and slightly coneave side upper- 
most. With the front pair of legs the spider grasps this slightly 
concave surface of the door and pulls. The second pair of legs 
are placed against the edge of the door nearest the hole to pre- 
vent it sliding; the remaining pairs of legs are inside the hole 
and with them he obtains a purchase for the pull, so that the 
