DESCRIPTIVE REMARKS. 
Ir has been sufficiently proved that the three great divisions—Patmo- 
zoic, or Primary ; Mxsozorc, or Secondary ; and Catnozorc, or Tertiary ; 
under which the whole series of Fossiliferous Rocks are grouped, are 
distinguished by an assemblage of organic remains, differing essentially 
in character the one from the other ; and that the Formations or Periods, 
second in importance, have also a peculiar and distinct set of Fossils; and 
even the minor subdivisions of strata, although they may not contain 
an entirely different assemblage, are sufficiently varied to allow of their 
identification (in the British Islands at least) by means of the fossil 
remains of extinct plants and animals contained in them. 
The study of these fossils and their comparison with existing plants 
and animals constitute the science of Paleontology; and it is from a 
knowledge of the laws derived from this study geologists are enabled 
to determine with certainty the succession of strata, and to trace out 
by their aid many points in geology which would otherwise be obscure 
and inexplicable. 
Each Formation, or group of strata, are considered to bear a corre- 
sponding importance in Geological, or past time with what are termed 
Natural History Provinces in Geographical Distribution, or present 
space, being like them characterized by a peculiar Fauna and Flora 
(animals and plants), differing from those of other Formations. 
The first to point out the utility of organized Fossils in the identity 
of strata was William Smith, at the commencement of the present 
century. That acute and much-esteemed observer has since been fol- 
lowed by others eminent in the same branch of science, whose labours 
as separate volumes, and in the publications of the various scientific 
societies, and periodicals, may be consulted with advantage by those 
who wish to enter more extensively into the consideration of the 
subject. ; 
To explain the position in the Animal Kingdom, of the Fossils figured, 
the following outline Table of Classification may be found useful :— 
