The Naturalists’ Companion. 
HISTORICAL GEOLOGY. 
A SERIAL. 
y,Y I'EANKIAN C. JOHNSON. 
CHAPI’ER V. 
III. CARBONIFEROUS AGE. 
This was the age of coal-plants. 
Din ing this age all our coal was made. 
True spiders, scorpions, insects, reptiles, 
etc., ap])eared in great numbers. The 
land was covered with a luxuriant vege¬ 
tation. '1 he tall trees of this age much 
resemble the ferns and herbs of a mod¬ 
ern meadow. 'Phis age is divided as 
follows: 
CARBONIFER¬ 
OUS AGE. 
3- 
2 . 
I. 
Permain Period. 
Carboniferous Period. 
Sub-carboniferous P’d. 
SUB-CARBONIFEROUS PERIOD. 
'Phis formation is found among the 
Appalachians ; also in Iowa, Illinois and 
Mississippi. 
During this period the land was large¬ 
ly beneath the sea, though not at a great 
depth. "Phe limestone abounds with 
crinoids, and is often termed “crinoidal 
limestone.” 
Not much coal was made during this 
period. 
At Pottsville, Pa., the foot prints of 
reptiles are found, som.e having a stride 
of thirteen inches. 
'lil 
CARBONIFEROUS PERIOD. 
d'his formation includes nearly all the 
great coal beds of the world. 
Plants are the most common fossils. 
During this age the earth was covered 
with vegetation. The leading forms 
were tree-ferns, club-mosses and rushes. 
Ferns which now grow at our feet, then 
were mighty trees. 
The LEPIDODENRIDS, a gigantic club- 
131 
moss, was very abundant. They were 
from fifty to sixty feet high. 
I'he CALAMITES were a kind ot rush 
which grew to the height of twenty feet 
or more. 
The siGiLLARiE was frequent in the 
great jungles of this period. They often 
grew to the height of sixty feet. 
Conifers, or cone-bearing trees, are 
not uncommon. 
The seas of this period abounded in 
crinoids, corals and fishes. The land 
had its insects, spiders and reptiles. 
PERMAIN PERIOD. 
This formation is found in Kansas 
and Texas. ■ 
Reptiles are numerous. 
d’he coal had been stored in the earth 
before this period. 
CHAPTER VI. 
MESOZOIC TIME. 
This time has but one age, that of rep¬ 
tiles. It is divided as follows : 
AGE OF 
3- 
REPTILES. 
Cretaceous Period. 
Jurassic Period. 
Triassic Period. 
These periods have never been fully 
separated in America. 
The rocks of this formation are found 
along the Connecticut Valley. Also in 
New Jersey, Pennsylvania, A^irginia, 
North Carolina, Colorado and Nevada. 
'Phe vegetation includes numerous 
kinds of ferns, conifers and calamites. 
But there were no forests ofuEPiDODEN- 
DRiDS or siGiLLARiDS. Ill their place 
the OYAD appeared. 
Birds and animals now appear for the 
first time. 
The AMMONITES aie plentiful. 'Phey 
had chambered shells like the or'phoce- 
RATITE. 
'Phe BELEMNiTE is commoii. It is the 
