In its general treatment of the subject this volume follows the lines of The Deer of All Lands; generic and sub-generic groups, as well as species and sub-species, being, so far as possible, made to have the same relative rank as in the latter. A similar prominent position is also given to the English names of the various animals described.<br><br>Much that appears in the introductory portion of the companion volume has a bearing on the present work. And it has accordingly been deemed unnecessary to repeat either the distinctive characteristics of the group Pecora, the subdivisions of the Tertiary period, or the names and limits of the geographical regions into which the surface of the globe may be divided; all these being detailed in The Deer of All Lands.<br><br>One feature of the latter - the numerous photographs of living animals - will be missed in the present volume. But this is unavoidable, as there is no collection in this country of the animals described in the sequel comparable with the one which afforded the illustrations in question.<br><br>While the majority of the plates have been drawn by Mr. J. Smit, a few are from original and, with one exception, hitherto unpublished sketches by Mr. Joseph Wolf.