PREFACE. The object of the present work is to furnish the student of Geology and the general reader with a compendious account of the leading principles and facts of the vast and ever-increasing science of Palaeontology. In carry ing out this object, all superfluous details have been rigidly excluded, and the Author has endeavoured to restrict himself entirely to those facts which are abso lutely necessary to any one who would study Palaeon tology as a department of science, sufficiently distinct to stand alone, and yet most closely connected with the sciences of Zoology and Botany on the one hand, and with Geology on the other hand. In the First Part of the work is given a general ac count of the principles upon which the palaeontological observer proceeds. In the Second Part of the work, Palaeontology, or the past history of the Animal Kingdom, is treated of; and here much more space has been devoted to the Inver tebrate than to the Vertebrate groups—upon the ground that it is chiefly, or almost exclusively, with the former that the ordinary palaeontological student has to deal. The Third Part of the work gives a brief and very general view of Palaeobotany, or the past history of the