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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 edition. Excerpt:... beds"2 and so-called "somber beds" of Montana, the "Ceratops beds" or "Lance Creek beds" of Wyoming, and their stratigraphic and paleontologic equivalents elsewhere, are to be regarded as constituting the lower member of the Fort Union formation, and are Eocene in age. *" Historical Summary. To all students of the late Cretaceous and early Tertiary formations of the northwest, the Fort Union formation is a familiar term. The name was originally given by Dr. F. V. Hayden3 in 1861 to his great lignite group which: "Occupies the whole country around Fort Union, extending north into the British possessions, to unknown distances; also southward to Fort Clark." At the same time it was stated that the formation had also been observed under the White River group on the North Platte River above Fort Laramie, and on the west side of the Wind River Mountains. The beds were described as consisting of clays and sands, with round ferruginous concretions, and numerous beds, seams and local deposits of lignite. The fossil contents were very abundant, consisting of great numbers of dicotyledonous leaves, fresh-water shells of several genera, scales of Lepisosteus, together with bones of Trionyx, Emys, Compsemys, crocodiles, etc. The abundant fossil plants obtained by Doctor Hayden were submitted to Dr. J. S. Newberry for study, and his report on them was published in 1868.4 The plants were collected at various points on the Missouri River, at Fort Clarke, at Red Spring thirteen miles above, at Fort Berthold, at Crow Hills, one hundred miles below Fort Union, at the mouth of the Yellowstone, on O'Fallon's Creek one hundred miles above the mouth of the Yellowstone, and in the valley of that stream. On account of their association with invertebrates...