Excerpt from Elements of Natural History, Vol. 2: Adapted to the Present State of the Science, Containing the Generic Characters of Nearly the Whole Animal Kingdom, and the Descriptions of the Principal Species It has been observed, as a distinction between the vertebral and the invertebral animals, that while in the former the bones or hard parts are more or less formed of phosphate of lime, the hard parts of the latter, such as the shells of the Mollusca and Crustacea, and the stony matter of corals and madrepores, are chiefly composed of carbonate of lime. 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.