200 



AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



u]>nii wliicli tlie entanglement hud oecnrred is (juite cnt away. Tlie sjiiiler 

 thereupon proceeds to operate the ivmaining parts of her snare, which, in 

 time, is thus destroyed hy sections, as will be fully illustrated hereafter. 



The second mode of operation resembles that of the Triangle spider, 

 Hyptiotes cavatus (Hentz). It is at this point that the habit of our Ray 

 sjiider becomes particularly interesting. The Triangle sjsider makes a tri- 

 angular web, which is in fact an orb sector, composed with 

 Resem- unvarying regularity of four siurally crossed radii converging ap- 

 HvDti t . proxim^itely \\Y>on a single line. Upon this line the sj)ider hangs 

 back downward, grasping it with all her feet, and having a por- 

 tion of the line rolled up slack Ix'twecn her two hind pairs of feet. Tims 

 the forward and back parts of the traplinc arc taut, while tlie interme- 

 diate pai't is slack. The spiral parts of the snare are also taut. When 



the web is struck by an insect, 

 the spider suddenly releases 

 her hind feet, the slack line 

 sharply uncoils, the spider 

 shoots forward, the whole web 

 relaxes, and the spiral lines 

 are thrown around the insect. 

 This is repeated several times 

 before the prey is seized. (See 

 description and cuts in Cha))- 

 tcr XI.) 



Precisely the same action 

 characterizes the Ray spider. 

 Her ordinary position, or at 

 least tlie one in whicli I most 

 fri'(|ucntly observed her, is a 

 sitting posture, back upward, 

 as shown at Fig. 187. The axes of the rays are held in the third and 

 fourth pairs of legs, the fourth commanding the ujiper, tlie third the lower 

 series, quite habitually, as it appeared to me. A sort of " has- 

 Posture j^g^ » Qj. sygtem of connecting lines, shown at Figs. 187, 195, 

 Snare unites all the feet, seeming to converge toward the fore feet (per- 

 hap.s, upon the second pair), where they gra.sp the trapline. It 

 is upon this foot basket that the si)ider sits when her net is bowed. 



This, however, is not tlic invariable posture; in the reconstruction of 

 the rays and shifting of the axes, as the day's work tells ui)on the snare, 

 the spider will vary her posture to that of Fig. 191. The trapline gen- 

 erally has a direction downwanl rather than upward, so that the head 

 and fore feet lend to be depressed below the abdomen. Figs. 192, 193, 

 and this depression may gradually result in the complete inversion of 

 the animal, so that she assumes the natural position of Orbw'eavers. I 



Fir,. 194. Ila.v .spider (greatly enlarged) in position, back down- 

 ward, on a taut snare. To show the slack line coil, SI. The 

 po.sitions of the feet on the foot basket are marked by nu- 

 merals ; a, b, c, the axes of several rays. 



