214 RECORDS OF THE AUSTRALIAN MUSEUM. 



trop. occid. (africana E. Sim.) ; Asia trop. (spinipes C. Koch) ; 

 Malaisia ; Papua si a ; Nova-Hollandia et Polynesia ; Amer. sept, 

 calid. et An til he (heptagon Hentz)." 8 



The webs of A. cemulce and A. cetherea, according to Workman's 

 description and figure are much alike. 4 The orbicular portion 

 varies from fifteen ins. to seventeen ins. in diameter, and is com- 

 posed of from twenty-five to forty-eight rays ; the inner spiral has 

 from six to nine turns ; the free zone measures about one inch ; 

 and the outer spiral has from twenty-five to fifty-six turns. At the 

 centre of the web, and extending from the inner lines of the 

 outer spiral right across the free zone, there are two distinct 

 ribbons of white silk which meet at the centre, cross each other, 

 and so produce the tigure of a St. Andrew's Cross. Sometimes 

 the ribbons extend well into the inner rings of the outer spiral, 

 but each ribbon is always zig-zaged in outline. Other species 

 also weave a ziy-zag ribbon of silk (in fact this feature is peculiar 

 to the webs of these orb-weavers), but in some instances the 

 ribbon is a single one, and is placed perpendicularly, in others 

 it takes the form of a more or less round ring, much like the 

 ribbons or stubilimetita in the webs of some exotic Uloboridae. 

 None of our Australian Argiopinse, so far as I have been able to 

 observe, make what Dr. McCook describes as a central shield, 

 but it is quite possible that some of our native species — at any 

 rate the more typical forms — may do so. Speaking of this in 

 connection with the American Argiopiiue, McCook says : — 



"The peculiarity which first strikes the observer is the oval 

 shield of white silk which covers the hub. This is thickest and 

 closest in the centre, and grows thinner and more open towards 

 the margin, where it gradually merges into the radii which are 

 attached to it. In the adult spider it is usually about two inches 

 long by one and a half wide. Attached to the shield above and 

 below, and extending upward and downward between two radii, 

 is a zigzag ribbon of white silk, an inch or more long and one- 

 fourth of an inch or more wide. It traverses the whole central 

 space, and extends downward about two inches until it is lost in 

 the spirals of the lower half of the orb.""' 



From the time when the young Argiope spreads its first 

 orbicular snare, the zigzag ribbon is present, but it is always 

 much more highly developed in the webs of adults. The question 



■'Simon— Hist. Nat. Araignees, 2nded., i., 1S92, p. 7t>'.'. 

 'Workman — Lor. cit., p. 27, tig. h. 



•McCook — American Spiders and their Spinning Work, 1889, i., p. 97, 

 figs. 52 and 89. 



