O1 
Or 
GENPRAL CHARACTERISTICS OF ORBWEAVERS SNARES. 
and a close observation of her feet will show that the claws grasp, and 
even draw out somewhat the lines which represent the radii continued. 
Every motion of the net is thus communicated more readily 
le through the taut lines to the sensitive feet. The brushes or 
ub. ; : : : . 
tufts of delicate hairs with which these organs are provided, 
and which are in contact with the lines, must greatly increase the sensi- 
tiveness of the creature to every movement. 
This natural telegraphy is, perhaps, also aided by a short line extend- 
ing from the spinnerets to the upper part of the hub. This line is apt 
to divide into two, or radiate into several branches near the hub. In this 
position, of course, the apex of the spider’s abdomen is slightly elevated 
(Fig. 51). However, the chief design of this habit is probably to hold the 
aranead to her snare when she rushes after her 
prey, or to give her a point of attachment for 
dropping out of the web, or running from it in 
case of assault, with similar advantage when she 
may wish to return. 
2. The Sheeted Hub is wholly covered by a 
closely woven sheet of white silk, against which 
the under part of the spider is placed — 
aaa as she hangs thereon. The type of 
this form of hub is that made by the 
Basket Argiope, A. cophinaria, (Walck.), the largest 
and one of the most beautiful of our indige- 
nous Orbweayers. It is shown at Fig. 52, where 
a thick, irregular shield like piece two inches long 
and one and a half wide, covers the entire hub. 
Above, it extends in a broad ribbon of the same Bie hi Sian cena hex 
consistency to the spiral space, a distance of hub, Argiope argyraspis. 
one and seven-eighths inches; and below, it terminates in a narrow, zigzag 
ribbon two inches in length. (Fig. 52.) 
3. The Open Hub is entirely free from any spinningwork, being a 
small opening in the centre of the orb, that is, the point toward which 
the radii tend. It is characteristic of snares spun by the genus 
er Acrosoma, and prevails largely in horizontal orbs. But it is 
frequently found in the webs of spiders whose general habit is 
to spin a meshed hub. Such variation in habit of course prevents us 
from taking these peculiarities of the hub as characteristics of absolute 
determinative value. Nevertheless, they are valuable, and will 
ae be found generally distinctive. The Notched Zone (NZ, Fig. 
49) is a short series of spiral lines, ordinarily from four to ten 
in number, immediately surrounding the hub. These spirals do not 
cross the radii directly, but diagonally, thus causing a notch or angle 
on each side when they are drawn taut. In other words, the spiral line 
