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GENERAL CHARACTERISTICS OF ORBWEAVERS SNARES. 59 
Certain species (indeed, the habit has its representatives among several 
genera) further strengthen the notched space by a close, plain band of 
white silk, which ordinarily extends between two radii, along the perpen- 
dicular diameter upward from the hub to the spiral space. (Fig. 54.) 
Sometimes also the ribbon reaches both upward and downward from the 
hub, and takes the form of a scalloped band or thick winding cord. This 
peculiarity prevails in all our indigenous examples of the genus Acrosoma, 
and is also quite characteristic of the exotic species of the same genus. 
Our beautiful and familiar representatives of the genus Argiope (A. cophi- 
naria and A. argyraspis Walck.)! have the same habit. (See Figs. 55.) 
Some species, as frequently Argiope argyraspis, add to this perpendicular 
ribbon, on either side thereof, one or more semicircular zigzag cords, which 
further tend to strengthen the central part of the orb. Some species of 
Uloborus have a similar habit, but also at times throw the cord entirely 
around the notched space, making a series of circles. (Figs. 56 and 57.) The 
perpendicular cords are sometimes extended above and below the notched 
space, and terminate in serpentine folds, bulb shaped tufts, or tapering 
points. They give a striking and beautiful appearance to the web, the 
graceful lines, and thick, white, flossy texture showing in pretty contrast 
against the radii and spirals. Examples of these peculiarities will be found 
among the descriptions of characteristic webs. (See Chap. VI.) 
These bands and cords, besides probably serving as braces, are used by 
the spider as supports when she hangs at the open hub. Acrosoma rugosa 
will generally be found hanging by her hind pair of legs to the lower end 
of the ribbon. 
1 Bpeira fasciata Hentz, and Argiope transversa Emerton. 
