116 
BLUEFIELDS. 
be cut longitudinally through with scissors, the inci- 
sion passing through the midst of the lid. 
The mode of construction I judge, from exami- 
nation of many nests, to be this. The Spider digs a 
cylindrical hole in the moist earth, with her jointed 
fangs or mandibles, carrying out the fragments as 
they are dislodged. When the excavation has pro- 
ceeded a little way, she begins to spin the lining 
which forms the dwelling. I conclude thus, because 
nests are occasionally found a few inches in length, 
with the lid and upper part perfect, but without any 
bottom, these being evidently in course of formation. 
I suppose that she weaves her silk, at first, in uncon- 
nected patches, against the earthy sides, perhaps 
where the mould is liable to fall in ; and thus I account 
for the loose rough laminae of silk that are always 
found projecting from the outer surface. These are 
overlaid with other patches more and more extensive, 
until the whole interior walls are covered ; after which 
the silk is spun evenly and continuously all round the 
interior, in successive layers of very dense texture, 
though thin. Under the microscope, with a power 
of 220 diameters, these layers are resolved into 
threads laid across each other and intertwined in a 
very irregular manner ; some are simple, varying from 
y— ^th to 20 ^ 0 ^^ diameter, and others 
are compound, several threads, in one part separate, 
being united into one of greater thickness which 
cannot then be resolved. No pellets of earth are ever 
interwoven with silk to form the outer layers of the 
walls, though the adhesive nature of the silk, when 
freshly spun, causes fragments of earth to remain 
