THE RAY SPIDER AND HER SNARE. 



199 



Fig. 192. Ray spider seat^ 

 ed upon her foot basket, 

 back upward. 



Figs. 187 and 189, at the point where the rays converge, grasping the axes 

 with tlie four hind feet. She has the posterior part of her abdomen 

 toward her snare, tlius reversing the attitude of all her tribe. Moreover, 

 her back is turned upward. The two front feet seize the trapline and 

 draw it taut. Tlien, precisely as a sailor pulls upon a rope, " hand over 

 hand," the little arachnid's feet move along tlie trap- 

 line, one over another. As she moves, going, of course, 

 awa}' from her net, the axes of the rays, 



, „ held firmly in the hind feet, follow her ; the 



till© tontir©. 



centre or the .snare bears niward, the otlier 



parts are stretched taut, and the web at last has taken 

 the form of a cone or funnel as at Figs. 190, 191. 

 In this position the snares continually suggested an 

 umbrella with ribs reversed by the wind and the cov- 

 ering strijiped loose from the top of the handle. Fig. 

 190 gives a side view of the web when thus bowed or 

 drawn taut; another snare is shown at Fig. 191, as seen 

 from Ijehind. These snares were located within cavi- 

 ties formed by the dropping away of stones from the 

 ruined dam breast in which they were first discovered. 



In the example sliown at Fig. 191 the spider has moved quite down 

 the trajiline to the surface of the little twig projecting into the cavity to 

 which it is attached. It will thus be seen that the snare is more or less 

 a plane surface, or more or less conical, according to the position of the 

 animal upon the trapline and the degree of tension thereof. 



II. 



When an insect strikes the snare, the spider has two modes of operat- 

 ing. The first somewhat resembles that of the ordinary 

 Orbweaver, in that the insect is simply permitted to en- 

 tangle itself, and is then taken, swathed, re- 



j.tF o^ '^^ turned to the centre, and eaten. There is, 

 the Snare. , • t^^ i ,. ■ ■, 



liowever, this difference: before the spider goes 



to the insect, the axes of the snare are twisted or knotted 



by a rotary action of her body and movement of the 



legs, so that the parts of the orb unbroken by the captive 



remain taut. Fig. 188 re^jrcsents a snare thus " locked," 



or, perhaps I might more properly say, " keyed." The 



trapline is now relaxed, although its elasticity is such 



that the change can scarcely be noticed. The spider 



then moves U2)on her victim, quite habitually cutting out 



the spirals with her mandibles as she goes. When the 



insect is ensnared well towards the circumference of the web, and indeed, 



for the most i^art, in other cases also, it results that the ray or sector 



Fig. 193. Position on 

 foot basket with head 

 bent downward. 



