2 
INTRODUCTION. 
each of which is distinguishable not only by the different character of material composing it, 
but also by fossil remains found therein, which afford a means for proximately determining the 
time required in their formation. These several layers may be likened to the figures on the dial 
of a clock, since they serve to mark the time, or rather epochs, or eras, in the earth’s existence, 
and to each is therefore given a name to indicate the infinitely great periods that have elapsed 
since God’s hand began the work of fashioning the world. 
These general divisions are again subdivided, just as the hours on the clock are divided into 
minutes, in order that the measurements of time may be more exactly reckoned. The general 
divisions, arranged in their regular order, are known by the following scientific names, viz. : The 
Archaean (meaning beginning ), the Palaeozoic (ancient life), the Mesozoic (middle life), and the 
Neozoic (new life). The subdivisions of these general groups are represented in the following table: 
Mr. Hinman has made 
another division, in which 
the special and characteristic 
fossils of each period are 
given, as also the relative 
time occupied, so to speak, 
by each epoch, but in which 
the orders are reversed ; that 
is, on a descending scale, in¬ 
stead of an ascending table, 
as I have given above. This 
order has been heretofore in¬ 
variably observed by writers 
on geology and natural his¬ 
tory, though it is manifestly 
improper when applied to the 
XMAS OF TXMB— CORRESPONDING TO HOURS. 
PERIODS OF TIMB—CORRESPONDING TO MINUTES. 
Archzsan,. 
f Laurentian 
\ Huronian 
Pai^ozoic. 
Cambrian 
Lower Silurian 
Upper Silurian 
Devonian 
Carboniferous. 
Mesozoic,. 
Permian 
Triassic 
Jurassic 
Cretaceous. 
Neozoic,. 
i 
/ Tertiary 
\ Quaternary 
PRIMARY-ORiPALEOZOIC 
latter, since all nature proceeds upon an ascending scale. 
In the oldest, or Arch^an stra¬ 
tum, no fossil remains have been found, 
though this fact does not necessarily 
imply that there was no animal life on 
globe during that period. The 
His arrangement is as follows ; 
-OtALLOOI** 
-FliHH 
-AMRtllMAM 
ag 
our 
inconceivably great time that has 
elapsed, the immense superposition 
of stratum on stratum, and par¬ 
ticularly the metamorphosis that the 
strata have undergone by the action 
of fire, would have destroyed any 
trace of fossil remains, however nu¬ 
merous they may have been. But 
the absence of all fossils “prevents 
us from determining the relative ages 
of the different parts of this group,” 
as Hinman observes. 
The Paleozoic Era, on the 
other hand, is distinguished for the abundance of animal and vegetable life that then existed, 
though it was in this period that these evidences of abounding life first appeared. This primary 
animal life, however, was all of the simplest, I might say almost rudimentary, forms, so low in 
the scale as scarcely to be distinguishable from the vegetable. Representatives still survive in 
the frotozoanida, as will be found explained in this work. 
SECOND: 
fnv 
-BiRD* 
-HAMMAU 
