In the meanwhile several works professing the same object have issued from the press; and an enlarged edition of Sir C. Lyell's "Elements" has also appeared, in which the elementary principles of physical Geology are fully illustrated, and numerous figures given of the characteristic fossils of the several formations, or groups of strata. But that department of the science which especially treats of Organic Remains is necessarily considered in a cursory manner; and a work upon the plan originally contemplated by the Author seems still to be required, to initiate the young and uninstructed in the study of those Medals of Creation--those electrotypes of nature--the mineralized remains of the plants and animals which successively flourished in the earlier ages of our planet, in periods incalculably remote, and long antecedent to all human history and tradition. With this conviction the present volumes are offered, with such modifications of the original plan as circumstances have rendered necessary, as a guide for the Student and the Amateur Collector of fossil remains; for the intelligent Observer who may desire to possess a general knowledge of the subject, without intending to pursue Geology as a science; and for the Tourist who may wish, in the course of his travels, to employ profitably a leisure hour in quest of those interesting memorials of the ancient physical revolutions of our globe, which he will find everywhere presented to his observation. Crescent Lodge, Clapham Common, _May_, 1844. ADDRESS TO THE READER. "Some books are to be tasted--others to be swallowed--and some few to be chewed and digested; that is, some Books are to be read only in parts--others to be read, but not curiously--and some few to be read wholly and with diligence and attention."--Lord Bacon's Essays. Anxious that the "Courteous Reader" should derive from this work all the information it is designed to impart, the Author presumes to offer a few words in explanation of the plan upon which it has been constructed, and some suggestions as to the best means of rendering its contents most available to the varied tastes and pursuits of different classes of readers. In its arrangement, a three-fold object was had in view; namely, in the first place, to present such an epitome of Palæontology, the science which treats of the fossil remains of the ancient inhabitants of the Globe, as shall enable the intelligent Observer to comprehend the nature of the principal discoveries in modern Geology, and the method of investigation by which such highly interesting, and unexpected results, have been obtained..