Excerpt from The American Journal of Science, Vol. 32 Geology and Mineralogy - United States Geolog'cal Survey, 69. - Topo graphic and 6001c Survey of Pennsylvania orth Carolina Geological and Economic Survey: The Ice Age in North America, G. F. Wright, 70. - Characteristics of Existing Glaciem. W. H. Hobbs, 71.-variations Periodiques des Glaciers, XV' rapport, 1909, ed. Bruckner Physik der Erde, M. P. Rusi, 72. - Geological Survey of Sweden Fossils and Stratigraphy of the Middle Devonic of Wisconsin, H. F. Cleland, 73. Cambrian Geology and Paleontology, II, C. D. Walco'it: Carboniferous Flora of north-eastern Greenland, A. G. Nateorst, 74. - Trenton Echino derm Fauna at Kirkfield, Ontario, F. Springer Geology of the Thousand Islands Region Geology of the Poughkeepsie Quadrangle, C. E. Gordon, 75.-recently Described Minerals, 76. - Bismuth Ochers from California, W. T. Scealler: Natural cliissiflcation of Igneous Rocks, W. Cross, 77. 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.