1886.] A new Trap-door Spider. 587 
thin web over the aperture; into which she wove any materials 
which came to hand. The trap door at this stage resembled a 
rudely constructed, horizontal, geometrical web, attached by two 
or three threads to the earth at the mouth of the hole, while in 
this web were caught the bits of earth, roots, moss, leaves, etc., 
which the spider had thrown into it from above. After the sec- 
ond night the door appeared nearly of the normal texture and. 
thickness, but in no case would it open completely, and it seemed 
the spider was too much disgusted with her quarters to think it 
worth while to make a perfect door.” 
He also records the making of a door by a very young one of 
thi 
so that the door would open and shut? 
The only: thing he records which seemed at all analogous to 
the mode of making a trap door exhibited by the spider in my 
Possession is that manifested in the enlargement of nests and trap 
doors by Spiders as they grow larger, and consequently require 
nests of larger dimensions, This operation was not witnessed 
by him, however, but the additions to the size of the door were 
Proven by measurements and observations upon nests of young 
spiders at different seasons 
It would seem natural to suppose that in making slight addi- 
tions from time to time to the edge of the nest, the spider would 
cement pellets of earth, pieces of moss, etc., to the edge instead 
of first spinning a web ; unless the web is spun over the lower 
side of the door and made to project just far enough to fit the en- 
larged tube. In Plate xxi, Fig. 8, can be seen eight concentric 
“lines of growth,” as they might be termed, of the trap door, 
corresponding to the growth and needs of the spider. These I 
Judge to represent the successive enlargements of the door con- 
mitant with the enlarging of the tube. We can safely say that 
aese additions were made by cementing the material, piece by — 
Paan which forms each ring, to the edge of the door. These 
lines of growth ” are not present in the door made by the adult : 
fourth time : 
*gularity in the cementing of the particles, which might form — 
qpatvesting Ants and Trap-door Spiders, p, 118. 
dem, P. IT9, ‘ 
“Idem, pp, 123, 127 and 150, and Supplement, p» 2454 
/ 
S species, in which the threads, except at the hinge, were cut - 
Spider in Captivity. I induced the spider to make the door the Qe 
(Jan. 19, 1886) in order to observe if there was any 
= 
