222 KKCOHDS OF THE AUSTRALIAN MUSEUM. 



All these orb-weaving spiders have the habit of enshrouding 

 superfluous prey, or such as are powerful and likely to do damage 

 to the snare, with silk. As the victim struggles, the spider paj - 

 out a line of silk, which not only becomes entangled in legs and 

 wings, but is made to closely and tightly encircle the insect's body, 

 and so render it helpless. Insects thus enclosed may be seen 

 hanging on the outskirts of a web. 



It is really remarkable what differences are found to exist in 

 the common orbed web, when one takes the trouble to make 

 and compare notes. The old school of naturalists contented 

 themselves by simply noting the fact that spiders of certain 

 genera constructed geometric webs, and these were generally 

 accepted as being round or wheel dike. But, as a matter of fact, 

 all orb-webs are not round, nor is the hub always strictly at the 

 centre. The radial lines may be, and often are, longer above the 

 hub than below, and sometimes vice versa ; then again the number 

 of radii varies : there may be only seventeen of these, or more 

 than fifty. I have counted in different webs 17, 22, 24, 2f>, 26, 

 32, 36, and 52 radii ; but the differences are not specific. Three 

 webs made by one species, Araneus productus, L.K., among the 

 shrubs in my garden, had 26, 32, and 36 respectively. Another 

 interesting feature is that it is not necessarily the largest web 

 that has the greatest number oT radii ; indeed, I have most fre- 

 quently found that the smaller webs made by the diminutive 

 species of Araneus have not only more radii, but also a greater 

 number of spirals than those made by their larger congeners. 

 The snares of A. productus, A. heroine, and A. brisbance, L.K., 

 may each vary, and often do, both in size, number of radii, 

 number of spirals, and supporting lines or guy-ropes, but all these 

 variations are due to peculiarities of site. The webs of Araneus 

 are almost invariably parallel to the plane of the horizon, but 

 frequently exigencies of construction compel such an arrangement 

 of foundation lines as to deflect the snare more or less sharply 

 from the vertical plane. 



< hie of the commonest spiders around Sydney is Araneus 

 wagneri, mini 20 ; a species which, together with its web, nest, 

 ova-sac and other details of its life-history, I described and 

 figured souk; years ago. Another species common around Par- 

 ramatta and Liverpool, A. sylvicola, mihi, 21 makes, it is inter- 

 esting to note, a web like tl it of the former species; moreover, 

 its nest consists of a roll I if. and its ova-sac a folded one, 



Rainbow— Loc. cit., :.• ii., 1896, , " pi. xi.\., figs. 2, 2a, 2b, 2c, 2d, 

 and p. 335. 



2a Rainbow — Loc. cit , xxiii., 1897, p. 51 t, pi. xvii., figs. 4, 4a, and p. 536. 



