164 
POPULAR SCIENCE REVIEW. 
spines in passing over the extremities of the spinners draw 
from them lines which run into numerous flexures, in conse- 
quence of not being kept fully extended, and the purpose sub- 
served by the upper row of spines seems to be the detachment 
of these lines from the spines of the lower row by an upward 
motion. Should the efficiency of the flocculi become much 
impared they are either replaced by others or a new snare is 
constructed. 
In the month of June the female of this common species 
deposits about seventy eggs, of a pale yellow colour, not agglu- 
tinated together, in a cocoon of white silk of a loose texture, 
measuring -/^ths of an inch in diameter ; it is nearly of a plano- 
convex figure, and is connected with the interior surface of an 
oval sac of white curled silk, on the outside of which particles 
of mortar and other extraneous materials are distributed. This 
sac is generally constructed in or near the spider's retreat. 
The admirable adaptation of the structure and disposition of 
the calamistra to their action on the spinners, by which, 
under the directing influence of instinct, the curious snares of 
the Ciniflonidce are perfected, affords such obvious evidence 
of design as to supersede the necessity of alluding more 
particularly to the subject. 
Family Agelenidce. 
Several species of the genus Tegenaria , included in the 
family of the Agelenidce , are most commonly denominated 
house spiders, from the circumstance of their prevalence in 
the interior of buildings ; the webs that they construct in the 
angles of the walls and windows of such as are inhabited, 
proving a source of perpetual annoyance to tidy housekeepers. 
These species, Tegenaria domestica , Tegenaria atrica , and 
Tegenaria civilis , present marked differences in size, and in the 
designs formed by the distribution of their various colours ; 
but in habits and economy they so closely resemble each other 
that remarks on those of Tegenaria civilis , the most widely 
distributed and best known species of the three, and that also 
to which the appellation of house spider is most generally 
applied, will serve to illustrate the proceedings of the other 
two. 
The snare of this spider, consisting of a horizontal sheet of 
web, of a fine but compact texture, is most commonly attached 
by its lateral margins to walls and beams, forming by their 
transverse junction an angle in which a short tube, open at 
both extremities, is connected with the web ; this tube is 
usually occupied by the spider, to which it affords a retreat 
and a ready medium of communication with every part of its 
snare. During the summer and autumn the female constructs 
