backs and fled. Their numbers were estimated at 2000 men; the remnant of the force escaped across the campos to the village of Altar do Chao, twenty miles distant, whence they scattered themselves along the shores of the Tapajos, and gave great trouble to the Brazilians for many years afterwards. Several expeditions were sent from Santarem to reduce them, a task in which the Government was aided by the friendly Mundurucús of the Upper Tapajos, a large body of whom, under the leadership of their Tushaúa Joaquim, made war on the hostile Indians on the lower parts both of the Madeira and the Tapajos, until they were nearly exterminated.
The country around Santarem is not clothed with dense and lofty forest, like the rest of the great humid river plain of the Amazons. It is a campo region; a slightly elevated and undulating tract of land, wooded only in patches, or with single scattered trees. A good deal of the country on the borders of the Tapajos, which flows from the great campo area of Interior Brazil, is of this description. On this account I consider the eastern side of the river, towards its mouth, to be a northern prolongation of the continental land, and not a portion of the alluvial flats of the Amazons. The soil is a coarse gritty sand; the substratum, which is visible in some places, consisting of sandstone conglomerate probably of the same formation as that which underlies the Tabatinga clay in other parts of the river valley. The surface is carpeted with slender hairy grasses, unfit for pasture, growing to a uniform height of about a
