The character of the banks yesterday and to-day continues unchanged; they are rather high, rising now and then in bluffs and presenting the same mixture of reddish drift and mud deposit, with the gray, slaty rock below, cropping out occasionally. This morning we are stopping to wood at a station opposite the village of Fonte Bôa. Here Mr. Agassiz has had an opportunity of going on shore and examining this formation. He finds a thick bed of ferruginous sandstone underlying a number of thinner beds of mud clay, resembling old clay slate with cleavage. These beds are overlaid by a bank of ochre-colored sandy clay (designated as drift above), with hardly any signs of stratification. Yesterday we passed several lakes, shut out from the river by mud-bars, and seemingly haunted by waterfowl. In one we saw immense flocks of what looked at that distance either like red Ibises or red spoonbills, and also numbers of gulls. Our sportsmen looked longingly at them, and are impatient for the time when we shall be settled on land, and they can begin to make havoc among the birds. _September 17th._—Last evening we took in wood from the shore some miles below the town of Tonantins. I sat watching the Indians on the bank, of whom there were some fifteen or twenty, men, women, and children; the men loading the wood, the women and children being there apparently to look on. They had built a fire on the bank, and hung their nets or cotton tents, under which they sleep, on the trees behind. They made a wild group, passing to and fro in the light of the fire, the care of which seemed the special charge of a tall, gaunt, weird-looking woman, who would have made a good Meg Merrilies. She seemed to have but one garment,—a long, brown, stuff robe, girt round the waist; as she strode about the fire, throwing on fresh logs and stirring the dying embers, the flames blazed up in her face, lighting her tawny skin and long, unkempt hair, flickering over the figures of women and children about her, and shedding a warm glow over the forest which made the setting to the picture. This is the only very tall Indian woman I have seen; usually the women are rather short of stature. When the Indians had made their preparations for the night, they heaped damp fuel on the fire till it smouldered down and threw out thick clouds of smoke, enveloping the sleeping-tents, and no doubt driving off effectually the clouds of mosquitoes, from which the natives seem as great sufferers as strangers. These upper stations on the Amazons are haunted by swarms of mosquitoes at night, and during the day by a little biting fly called Pium, no less annoying.