The Index to the present volume has been formed on the basis of that of Schneider, and considerable pains have been taken to add as many names as possible from other sources, especially the Index of Strack, and Külb's recent translation of the History of Animals, both of which contain identifications of a great many animals. A few identifications have also been added from Liddell and Scott's Lexicon, as well as from Professor Bell's Catalogue of Animals in Captain Spratt's work on Lycia; and the cephalopods are named from Professor Owen's article on that class, in the Cyclopædia of Anatomy. It is hoped, therefore, that the Index will be found to contain a greater number of suggestions for the identification of the animals mentioned by Aristotle than have been hitherto published collectively. It is also right to add, that it has been compiled after the translation was completed; and, therefore, in any differences which may be found between the identifications at the foot of the page and those given in the Index, the reader will rather prefer the latter, as the result of later research in works which were not accessible when the translation was made. April 30, 1862. R. C. ANALYTICAL TABLE OF CONTENTS. BOOK I.--The work commences with a general review of the animal kingdom, and several suggestions for a natural arrangement of animals in groups, according to their external form or their mode of life, a comparison of animals among themselves, and a description of some of their habits. Aristotle then introduces the human form, the best known to man, as the standard of comparison to which he refers the rest of the animal kingdom. The concluding chapters of this book are occupied with a description of the several parts of the human body, both internal and external. BOOK II.--In the second book the different parts of animals are described. The animals are arranged in various groups, viviparous and oviparous quadrupeds, fish, serpents, birds. The only animals described are those with red blood: the description of the rest being reserved for the fourth book. Their internal organs are also described; and in the course of the book a few animals, as the ape, elephant, and chameleon, are especially noticed. BOOK III.--The third book commences with a description of the internal organs, beginning with the generative system. A considerable portion of the book is devoted to the course of the veins; and Aristotle quotes from other writers, as well as states the result of his own observations. He then describes the nature of other constituent parts of the body, sinews, fibres, bone, marrow, cartilage, nails, hoofs, claws, horns, and beaks of birds, hair, scales, membranes, flesh, fat, blood, marrow, milk, and the spermatic fluid.