Excerpt from A Guide to the Fossil Invertebrates and Plants in the Department of Geology and Palaeontology in the British Museum (Natural History) Before visiting the Geological Galleries upon the east side, it is very desirable that the student should have seen and become acquainted with the recent Zoological collections on the west side of the entrance; and, if he would properly understand the structures and characters of animals, he should spend some time in studying the beautiful series of objects in the Introductory Collection, which occupies the cases in the bays or recesses on each side of the great Central Hall. As an introduction to the Geological Galleries a few words are needed. Geology embraces the investigation of everything connected with the formation and history of the earth which we inhabit, both organic and inorganic. In the Mineralogical Gallery, on the east side, upon the first floor, will be found a very complete exposition of specimens illustrating the nature and properties of rocks and minerals forming so large a part of the earth's crust; but in the Geological Galleries the exhibited series is necessarily confined to some illustrations of the sedimentary and organically formed rocks, arranged stratigraphically in Gallery XI, and to as complete a series as possible of the re mains of the animals and plants which have been entombed in the various deposits which compose the ground beneath us. These rocks and sediments and the organisms found in them are of very different relative ages (see the Table of Strata), some, like the Cambrian and Silurian, being extremely ancient, and containing only invertebrate forms of life, the species of which are now quite extinct; others, like the Eocene strata, being very rich in remains of all classes of organisms; whilst the later Tertiary deposits often yield abundant evidence of animals very nearly related to those which are living at the present day. 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.