Excerpt from Description of the Remains of Extinct Mammalia and Chelonia, From Nebraska Territory: Collected During the Geological Survey Under the Direction of Dr. D. D. Owen The specimens are very dense, and in many of them the Haversian canaliculi and areolae, and in the case of the long bones the medullary cavities, are filled partially or completely with silex. In the latter positions, the silex is sometimes beautifully crystallized, or has a botryoidal, chalcedonic arrangement. The change which has taken place in the chemical constitution of these fossilized bones has been determined through analysis by Dr. Owen, and is given in his report. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.