38 RIO DE JANEIRO. (cHapP IL 
cally, as is invariably the case with the genus Epeira: they were 
separated from each other by a space of about two feet, but were 
all attached to certain common lines, which were of great length, 
and extended to all parts of the community. In this manner the 
tops of some large bushes were encompassed by the united nets. 
Azara* has described & gregarious spider in Paraguay, which 
Walckenaer thinks must be a Theridion, but probably it is an 
Epeira, and perhaps even the same species with mine. I cannot, 
however, recollect seeing a central nest as large as a hat, in 
which, during autumn, when the spiders die, Azara says the eggs 
are deposited. As all the spiders which I saw were of the same 
size, they must have been nearly of the same age. This gre- 
garious habit, ‘in so typical a genus as Epeira, among insects, 
which are so bloodthirsty and solitary that even the two sexes at- 
tack each other, is a very singular fact. 
In a lofty valley of the Cordillera, near Mendoza, I found 
another spider with a singularly-formed web. Strong lines 
radiated ina vertical plane from a common centre, where the 
insect had its station; but only two of the rays were connected 
by a symmetrical mesh-work ; so that the net, instead of being, as 
is generally the case, circular, consisted of a wedge-shaped seg- 
ment. All the webs were similarly constructed. 
* Azara’s Voyage, vol. i. p. 213. 
