INSECTS AND THEIR NEAR RELATIVES . 
39 
the habits of this spider (see Popular Science Monthly , 1875), 
illustrates the form of the web. It consists of four plain 
lines corresponding to the radiating lines of an orb web, and 
a series of double cross lines, which are spun by the cribel- 
lum and calamistrum. From the point where the radiating 
lines meet a strong line extends to one of the supporting 
twigs. Near this twig the spider rests, pulling the web tight 
so that there is some loose line between its legs, as shown in 
the enlarged figure. When an insect becomes entangled in 
one of the cross lines, the spider suddenly lets go the loose 
line so that the whole web springs forward, and the insect is 
entangled in other cross threads. The spider then draws 
the web tight and snaps it again. This may be repeated 
several times before the spider goes out upon the web after 
its prey. 
Uloborus (U-lob'o-rus).—The spiders of this genus make 
round webs which resemble at first sight those of the Orb 
Weavers ; but they differ from the ordinary orb webs in that 
