In preparing the present edition of this Text-Book, every section of it abreast of the onward march of Geological Science. Some portions have been recast or rewritten; others have been largely augmented by the incorporation of the results of the latest researches, while between thirty and forty illustrations have been added. As the new material thus supplied amounts to 300 pages, the work has now been divided, for more convenient use, into two volumes; but to ...
