THE FEATHERFOOT SPIDER, ULOBORUS PLUMIPES. 



179 



The same author says that the spiral hues of Hyptiotes and Uloborus 

 have a strong, smooth tliread through the centre. That of Hyptiotes, which 

 he examined fresh, had the finer 



Sph'al 

 Thread 



part arranged in reg- 

 ular leaves or scallops, 

 in which the separate 

 fibres could not be distinguished. 

 The thread of Uloborus, at least 

 when old and dried, had the 

 loops longer and less regular, and 

 he had not been able to distin- 

 guish the separate fibres except 

 at the edges of the band. To 

 my eye the spiral seemed to be 

 a single continuous flocculent fil- 

 ament without any supporting 

 thread, thus differing from Hyp- 

 tiotes. But of this I am not 

 confident. Under a common 

 hand lens it has a milky or 

 filmy hue. 



The position of the spider upon her snare is very much like that of 

 Tetragnatlia. I have found her stretched out underneath the hub, with 

 the legs extended fore and aft almost in a straight line with the 



Fig. 167. Unfinished web of LHoborus Walckenaerius. 

 (After Enierton.) 



Position 

 on Snare. 



ribboned decorations to which the feet clung. Sometimes, how- 

 ever, she turned and hung beneath the hub at a position at 

 right angles with the ribbon. 



One young specimen, captured upon her snare, I saw repairing the 

 broken margins of her web. It w^as done line after line, one 

 j^ ^ radius and one spiral at a time, precisely in the manner common 



to other Orbweavers. The broken lines were cut out, and new 

 ones substituted, or were picked up by the spider's feet, spliced, and 

 stretched into position. She worked very deftly and rapidl}-. 1 saw her 

 capturing a small insect, a gnat. The two hind legs were used for ra})idly 

 pulling out the enswathing thread, while the second and third legs re- 

 volved the insect and held it to the web. According to Hentz, Uloborus 



,. . ,...., has the habit of vio- 



" lently shaking her 

 web when threatened. 

 But when at rest he 

 always found it in an 

 inverted position underneath its orb, with its hind legs extended in parallel 

 lines like Tetragnatlia. This record of halnts, imperfect as it is, indubi- 

 tably i)laces Uloborus among the weavers of orbwebs. 



Fig. 168. Uloborus hanging beneath her orb. 



