Cuap. XII. FORAGING ANTS. 355 
Foraging Ants.—Many confused statements have been published in 
books of travel and copied in Natural History works regarding these 
ants, which appear to have been confounded with the Saiiba, a sketch 
of whose habits has been given in the first chapter of this work. The 
Satiba is a vegetable feeder, and does not attack other animals; the 
accounts that have been published regarding carnivorous ants which 
hunt in vast armies, exciting terror wherever they go, apply only to the 
Ecitons, or foraging ants, a totally different group of this tribe of insects. 
The Ecitons are called Taudca by the Indians, who are always on the 
look-out for their armies when they traverse the forest, so as to avoid 
being attacked. I met with ten distinct species of them, nearly all of 
which have a different system of marching ; eight were new to science 

Sack-bearing Caterpillar (Saccophora). 
when I sent them to England. Some are found commonly in every 
part of the country, and one is peculiar to the open campos of Santarem ; 
but, as nearly all the species are found together at Ega, where the 
forest swarmed with their armies, I have left an account of the habits of 
the whole genus for this part of my narrative. The Ecitons resemble 
in their habits the Driver ants of Tropical Africa; but they have no 
close relationship with them in structure, and indeed belong to quite 
another sub-group of the ant tribe. 
Like many other ants, the communities of Ecitons are composed, 
besides males and females, of two classes of workers, a large-headed 
(worker-major) and a small-headed (worker-minor) class ; the large-heads 
have in some species greatly lengthened jaws, the small-heads have jaws 
always of the ordinary shape ; but the two classes are not sharply defined 
in structure and function, except in two of the species. ‘There is in all 
