Superfamily Argiopoidea 



Genus HYPTIOTES (Hyp-ti'o-tes) 



The following is the only species of this genus that has been 

 described from the United States. 



The Triangle Spider, Hyptiotes cavatus (H. ca-va'tus). — 

 This inconspicuous spider will ordinarily be recognized by the 

 form of its web; the spider itself being so well-protected by its 

 form and colouring as to escape observation. It usually rests 

 close to a dead branch and resembles a dried bud of this branch. 



The adult female is one sixth inch in length. The outline 

 of the body is shown in Fig. 245. On the back of the abdomen 

 there are four pairs of slight elevations, on which are a few stiff 

 hairs. The male is one twelfth inch in length; the abdomen 

 is of a more slender form and the humps are not so prominent. 



The habits of this spider have been made well-known through 

 the writings of Dr. B. G. Wilder, who first described them more 

 than thirty-five years ago in the Popular Science Monthly (April, 

 1875). Its web is most often found stretched between the twigs 

 of a dead branch of pine or hemlock. At first sight it appears like 

 a fragment of an orb-web (Fig. 246) ; but a little study will show 

 that it is complete. It consists of four plain lines corresponding 

 to the radiating lines of an orb-web, and supported by these a 

 variable number of threads which appear like sections of the 

 spiral line of an orb-web. From the point where the radiating 

 lines meet a strong line extends to one of the supporting twigs. 



Each of the transverse lines supported by the four radii 

 is a hackled band consisting of a warp of two threads and a woof 

 of overlapping lobes of viscid silk like that of Uloborus (Fig. 236). 

 Each band is fastened to each radius by being applied to it length- 

 wise for a short distance; this makes the course of each band a 

 zigzag one. In Fig. 246 one can see that in the spaces between 

 the bands there is in each case a short section of the radius not 

 overlapped by the bands, which consequently appears as a more 

 delicate line; this is best shown on the two intermediate radii. 



The number of radii in the web of this spider is always 

 four; but the number of hackled bands varies greatly; it is usually 

 about ten, but often less than that number, and sometimes more 

 than twenty. 



The spider rests on the single line, upon which the four 

 radii converge, near the point where the line joins the supporting 



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