340 AMBRICAN SPIDERS AND THEIR SPINNINGWORK. 
In certain species the trapline consists of several threads, as, for exam- 
ple, in Epeira labyrinthea. In other species, where a single trapline is 
the rule, the same habit will be sometimes observed, as, for ex- 
ample, in the case of Zilla, whose trapline becomes a strangely 
complicated series of threads. (See Chapter VIIL, Fig. 118.) 
Labyrinthea connects the central portion of her orb with the silken dome 
or leafy shelter within her maze of intersecting lines, by a series of straight 
lines sometimes quite numerous. These make a little bridgeway between 
the tent and the orb. When the spider is within the tent the feet are 
reached beyond the borders and grasp at various points these lines. 
Sometimes the lines are twisted into a strong and single thread, either ac- 
cidentally or by the voluntary 
F action of the spider. 
ie ae ee When one takes a side 
— view of the orb (see Fig. 116, 
page 1388) he almost invaria- 
\\ : bly finds the centre 
\\ | a »& drawn inward and 
upward towards the 
| spider’s retreat, thus causing 
/) | all the radial lines to bow 
inward or toward one anoth- 
ein er. In this position the snare 
HN ier : 
bil PSY a in its general outline has a 
: striking resemblance to that 
of a Ray spider when it has 
been bowed by its proprie- 
—__———) tor in the manner described 
Fic. 331. The Stellate spider trapping with the scant and illustrated at Fig. 190, 
remnants of a snare. 
page 196. Epeira triaranea 
has the same habit of bowing her web upward and inward towards her 
den, and, indeed, such is the case with some other species; necessarily, 
more or less of this bowing of the orb must result from the habit of 
holding the trapline taut. But in the case of Labyrinthea the bowed 
condition of the web is more striking, I think, than in any other spe- 
cies with whose spinningwork I am acquainted, and is so noticeable that 
the most casual observer may see it. 
We come now to the use of the trapline as it is even more highly 
specialized in the habit of the Triangle spider. Here the line serves not 
: only the purposes common to the species already described, but 
Hypti- becomes a real instrument in the spider’s hands for springing 
her net. Such Orbweavers as Epeira strix and Epeira trifolium, 
when they are drawing their traplines taut, necessarily leave a 
little slack line between the point of seizure by the fore claws and the 
Multiplex 
Traplines. 
Trapline. 
