THE FEATHEEFOOT SPIDEK, ULOBORUS PLUMIPES. 



179 



Fig. 167. Unfinished web of Uloborus Walckenacrius. 

 (After Emerton.) 



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

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

 he examined fresh, had the finer 



part arranged in rcg- 

 Jr , ular leaves or scallops, 



in wliicli 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 fiocculent fil- 

 ament without any supporting 

 thread, thus differing from Hyp- 

 tiotes. But of this I am not 

 confitlent. 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 

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



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



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



on Snare. i i , , , , , , . ' 



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 was done line after line, one 

 g 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 sjiider's feet, spliced, and 

 stretched into position. She^ worked very deftly and rapidly. I saw her 

 capturing a small insect, a gnat. The two hind legs were used for rapidly 

 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 

 j^gsSH-^^^^ ^g]j when threatened. 



But when at rest he 

 always found it in an 

 inverted position underneath its orb, witli its hind legs extended in i)arallel 

 lines like Tetragnatha. This record of habits, imperfect as it is, indubi- 

 talily places Ulol)orus among the weavers of orljwebs. 



Fig. 168. Uloborus hanging beneath her orb. 



