[17] Long's Expedition to the Rocky Mountains, Vol. I, p. 361.
[18] Atwater, in Transactions American Antiquarian Society, Vol. I.
[19] Squier and Davis: Ancient Monuments of the Mississippi Valley, p. 283.
[20] Ibid., p. 284.
[21] Farquharson, in Proceedings of the Am. Association, 1875, page 296.
[22] Ibid., p. 297.
[23] Putnam, in Eleventh Annual Report, Peabody Museum, p. 235.
[24] I am indebted to Dr. Charles A. White, of the Geological Survey, for the identification of the numerous specimens of Unionidæ mentioned in this paper.
[25] Archæological Explorations by the Literary and Scientific Society of Madisonville, 1879.
[26] Putnam, in Eleventh Annual Report, Peabody Museum, p. 334.