262 



THE NATURALIST IN AUSTRALIA. 



regalis of Ludwig Koch. The photograph here reproduced represents the spider 

 one-quarter only of its natural size, and it is consequently a tolerably large species. 

 It is also a handsome one, being of a warm chestnut brown hue with bright yellow 

 bands across the dorsal surface of the body, which gives to it a somewhat wasp-like 

 aspect. The example in the illustration having had its ventral surface turned towards 

 the camera, this detail is not apparent. The feature most distinctly indicated in this 

 picture is the singular supple- 

 mental additions to its ordinary 

 orb-shaped web; these take the 

 form of four zig-zag, thick, ribbon- 

 like bands or rays of the web- 

 substance disposed obliquely and 

 at nearly right angles, and in 

 such manner as to form the let- 

 ter X. Argiope, in fact, as here 

 shown, stole a march on Professor 

 Rontgen centuries since in the in- 

 vention and practical utilisation 

 of mythical X-rays. As may be 

 discerned in the accompanying 

 photograph, the spider, when at 

 rest in the centre of its web, 

 has its eight legs disposed in 

 four pairs, which are precisely 

 parallel with, and are respec- 

 tively anchored for support to, 

 each of the four radiating rib- 

 bons. Dr. Henry McCook, in 

 his "American Spiders and their Spinning Work," includes descriptions of several 

 United States species of the genus Argiope, with especially copious details of the 

 largest and commonest form, Argiope cophinaria. This type is also in the habit of 

 strengthening its snare with ribbon-like zig-zag cords. The ribbon-webbing in this 

 form is, however, limited to a single band descending downwards from the web's 

 centre or "hub," or there may be a second one in the same straight line ascending 

 vertically above it. The immediate centre of the web is also in this type usually 



W. SacUle-Kent, Photo. 



ttlEENSLAND " X-RAY " SPIDER, Afffiope reffa/is, WITH HIM1ON-STRENGTHENED WEB. 

 ONE-FOURTH NATURAL SIZE. 



