11 SPIDERS 39 



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 a gregarious spider in 

 Paraguay, which Walckenaer thinks must be a Theridion, but 

 probabl}^ 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, the}' must have been nearly of the 

 same age. This gregarious habit, in so typical a genus as 

 Epeira, among insects, which are so bloodthirsty and solitary 

 that even the two sexes attack each oth?r, is a very singular fact. 

 In a lofty valle)- of the Cordillera, near Mendoza, I found 

 another spider with a singularl}-- formed web. Strong lines 

 radiated in a 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 segment. All the webs were similarly 

 constructed. 



' Azara's Voyage, vol. i. p. 213. 



Darwin's papilio fbronia. 1833, .now called agero.nia fero.nia, 18 



