On scrutinizing the shores of the island, on which I had encamped, innumerable helices, and other small univalves, were found; among these I observed a new species, which Mr. Cooper has described as planorbis companulatus.[168] There were bones of certain species of fish, as well as the bucklers of one or two kinds of tortoise, scattered around the sites of old Indian camp fires, denoting so many points of its natural history. Amidst the forest-trees before named, the betula papyraceæ and spruce were observed. Directing one of the latter to be cut down, and prepared as a flagstaff, I caused the United States flag to be hoisted on it. This symbol was left flying at our departure. Ozawindib, who at once comprehended the meaning of this ceremony, with his companions fired a salute as it reached its elevation. [168] Appendix. Having made the necessary examinations, I directed my tent to be struck, and the canoes put into the water, and immediately embarked. The outlet lies north of the island. Before reaching it, we had lost sight of the flagstaff, owing to the curvature of the shore. Unexpectedly, the outlet proved quite a brisk brook, with a mean width of ten feet, and one foot in depth. The water is as clear as crystal, and we at once found ourselves gliding along, over a sandy and pebbly bottom, strewed with the scattered valves of shells, at a brisk rate. Its banks are overhung with limbs and foliage, which sometimes reach across. The bends are short, and have accumulations of flood-wood, so that, from both causes, the use of the axe is often necessary to clear a passage. There was also danger of running against boulders of black rock, lying in the margin, or piled up in the channel. As the rapid waters increased, we were hurled, as it were, along through the narrow passages, and should have descended at a prodigiously rapid rate, had it not been for these embarrassments to the navigation. Its course was northwest. After descending about ten miles, the river enters a narrow savanna, where the channel is wider and deeper, but equally circuitous. This reaches some seven or eight miles. It then breaks its way through a pine ridge, where the channel is again very much confined and rapid, the velocity of the stream threatening every moment to dash the canoe into a thousand pieces. The men were sometimes in the water, to guide the canoe, or stood ever ready, with poles, to fend off. After descending some twenty-five miles, we encamped on a high sandy bluff on the left hand.