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J. H. Emerton—Cobwebs of Uloborus. 205 
Fig. 1 represents an unfinished web of Uloborus walckenerins 
seen in France, showing the central part still occupied by the 
preliminary spirals, a a, while the outer part is covered with 
curled threads, and the smooth spirals cut away leaving thick- 
ened spots, } 6, on the rays. In the finished web most of the 
spirals pass regularly around, but the outer ones are often 
more or less irregular as in Hpeira webs, according to the shape 
of the space in which the web is made. 
After laying her eggs, this spider, like many others, becomes 
careless about her web, and repairs it only enough to keep the 
cocoons in place, so that many imperfect and irregular webs are 
found at that season. I have seen such webs made by Uloborus 
walckenerius, and the only web I have seen of the American 
- Uloborus= Phillyra riparia Hentz (fig. 2), is imperfect from the 
same cause, but is evidently the remains of a nearly round 
web, the rays meeting somewhat nearer the upper than the 
lower edge. 
The thread of Ayptiotes and Uloborus has a strong smooth 
thread through the center. That of Hyptiotes, which I have 
examined fresh, has the finer part arranged in regular loops or 
scollops (fig. 3), a, b, in which the separate fibers cannot be dis- 
tinguished. The thread of Uloborus, at least when old and dry, 
has the loops longer and less regular, and I have not been able 
distinguish the separate fibers except at the edges of the 
and, 
The close resemblance of the web of Uloborus to those of the 
Epeiride makes the classification of this genus still more di 
cult, for while its structure shows its close relationship to 
Ayptiotes and the other Cinsflonide, it is highly improbable that 
the habit of making such complicated webs of the same kind 
should have been acquired separately by Uloborus and by the 
perride, 
