ntroductory portion of the work is devoted to a
consideration of the general principles of Palaeontology, and the
bearings of this science upon various geological problems--such
as the mode of formation of the sedimentary rocks, the reactions
of living beings upon the crust of the earth, and the sequence
in time of the fossiliferous formations. The second portion of
the work deals exclusively with Historical Palaeontology, each
formation being considered separately, as regards its lithological
nature and subdivisions, its relations to other formations, its
geographical distribution, its mode of origin, and its characteristic
life-forms.

In the consideration of the characteristic fossils of each successive
period, a general account is given of their more important zoological
characters and their relations to living forms; but the technical
language of Zoology has been avoided, and the aid of illustrations
has been freely called into use. It may therefore be hoped that
the work may be found to be available for the purposes of both the
Geological and the Zoological student; since it is essentially an
outline of Historical Palaeontology, and the student of either of
the above-mentioned sciences must perforce possess some knowledge
of the last. Whilst primarily intended for students, it may be
added that the method of treatment adopted has been so far
untechnical as not to render the work useless to the general
reader who may desire to acquire some knowledge of a subject of
such vast and universal interest.

In carrying out the object which he has held before him, the
Author can hardly expect, from the nature of the materials with
which he has had to deal, that he has kept himself absolutely
clear of errors, both of omission and commission. The subject,
however, is one to which he has devoted the labour of many years,
both in studying the researches of others and in personal
investigations of his own; and he can only trust that such errors
as may exist will be found to belong chiefly to the former class,
and to be neither serious nor numerous. It need only be added
that the work is necessarily very limited in its scope, and that
the necessity of not assuming a thorough previous acquaintance
with Natural History in the reader has inexorably restricted its
range still further. The Author does not, therefore, profess to
have given more than a merely general outline of the subject; and
those who desire to obtain a more minu