1982] 
Lubin, Opell, Eberhard, Levi — Uloboridae 
35 
Figure 5. Construction of U. conus web. (a) Sequence of attachments of sticky 
silk to produce the outer zigzag loop of rim sticky spiral. The spider started at the 
junction of the radius (Rl) and frame thread (F), attaching the cribellar thread at 
point A, walked along Rl toward the hub and attached the cribellar thread at point 
B, about half way between the frame thread and outer loop of non-sticky spiral (NS). 
The spider then continued inward along Rl, combing out cribellar silk, reached the 
non-sticky spiral and ran rapidly across it and 2/3 of the way out on R2 without 
combing out additional silk. It then continued to walk out on R2, combing out 
cribellar silk and attached the thread at point C, the junction between R2 and the 
frame thread. The sequence was then repeated, walking in along R2, attaching 
cribellar thread at point D, etc. (b) Sequence of attachments of cribellar silk to 
produce the normal sticky spiral. The spider attached cribellar thread at point A on 
radius Rl, walked in on Rl, combing out cribellar silk, until it reached the 
temporary, non-sticky spiral loop (NS), then ran along the non-sticky spiral and out 
on radius R2 without combing out cribellar silk and attached the cribellar thread to 
R2 at point B. 
dropped from it to a leaf below, attached her dragline to the leaf, 
and went back up the dragline and across the web to its hub on a 
radius, attaching the new dragline from the leaf to the hub. This 
formed the central guy thread of the cone. The spider then went 
down the guy thread, broke it, reattached it to a different point on 
the leaf, and then returned to the hub. By this time the hub was al- 
ready drawn down under tension, and the web formed a shallow 
cone. The cone was then elongated by cutting radii at their 
attachment to the hub, lowering their tension and then attaching 
them to the central guy thread by the sequence of behaviors shown 
in Fig. 6a, b. 
