TKAP-DOOR SPIDERS. 
115 
TRAP-DOOR SPIDERS. 
In digging their mountain-gardens the negroes 
often expose the curious subterranean nests of the 
Trap-door Spider {Cteniza nidulans), many of which 
are brought to me. This Spider makes its tubular 
dwelling in soft earth, frequently choosing cultivated 
ground, on account, doubtless, of this quality; each 
nest is cylindrical, or nearly so, from four to ten 
inches deep, and about one inch in diameter ; the 
bottom is rounded ; and the top, which is at the 
surface of the soil, is closed very accurately with a 
circular lid. They are not all equally finished, some 
being much more compact, and having the lid more 
closely fitted than others. Some have irregular 
bulgings, and ragged laminated ofif-sets on the outer 
surface ; but all are smooth and silky on the inside. 
This smoothness, however, does not preclude little 
irregularities or unevennesses of surface, nor is it 
glossy ; its appearance rather resembles that of paper 
which has been wetted and dried ; it is always of a 
reddish-buflP hue, but the outside is stained of the 
colour of the surrounding earth. The mouth of the 
tube, and the parts near it, are very strong; the walls 
here often having a thickness of from |^th to ^Jth of 
an inch ; but the lower parts are much thinner. The 
lid is continuous with the tube for about a third of its 
circumference, and this part may be called the hinge, 
though it presents no structure peculiar to itself; it 
is simply bent at a right angle, as is manifest if a nest 
