Note 31 — A GEOLOGICAL ROMANCE.
Reading edition
Dr. Samuel Aughey, Physical Geography of Nebraska, 1880. Prof. J. E. Todd, Science, April 23, 1886, and January 8, 1897. E. H. Barbour, Publication No. V, Nebraska Academy of Sciences. J. A. Udden, The American Geologist, June, 1891, and April, 1893. R. D. Salisbury, Science, December 4, 1896. G. P. Merril, Proceedings of the United States National Museum, 1885.