XU 
INTRODUCTION. 
Geology deals with the Earth, the composition of the various 
strata, or layers, of which it consists, their present and foimei 
extent, and the physical conditions under which they were 
deposited, and the changes they have since undergone. 
Palaeontology deals with the remains of ancient life found 
in the various layers, and strives, by comparison with living 
forms, to restore the successive faunas and floras which have 
passed away, and to trace by those relics their past dis- 
tribution, and thus to show the evolution of life on the earth 
from the earliest times to our own. 
So many good boohs on Geolog’y and Palaeontology lia\ e 
been published * that it is not necessary to give in such a guide- 
book as the present a treatise on the science, but merely to 
explain that the Vertebrata in the Galleries are arranged 
according to their zoological classes, orders, and families (so far 
as these can be ascertained) ; and upon the label to each is 
placed its name, its geological position, and the locality whence 
it was derived. In the Invertebrata and Plants each class is 
also grouped chronologically in order, from the latest deposits 
to the earliest in which it occurs. 
Whenever a specimen lias been figured and described in a 
scientific work, a green disk is affixed to it, and a reference is 
given to the author, and to the name and date of the work 
where it was published. 
Explanatory labels and illustrations have been introduced in 
many instances, to afford fuller information to visitors respecting 
the objects exhibited. 
The plan, facing p. 102, will serve to show the general arrange- 
ment of the cases and their contents. The small Table of 
Strata, on p. x, is given to indicate the range in time of the 
o-reat groups of Mammals, Birds, Reptiles, Pishes, Invertebrates, 
and Plants. 
H. W. 
* See specially “Manual of Palaeontology,” by Prof. IT. Alleyne 
Nicholson and K, Lydekker, in 2 yols. (3rd Edition). Wm. Blackwood and 
Sons, Edinburgh and London. 1889. 
