The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1890-06-26
THE EARLIEST ANIMALS.

of any living thing are the remains of
sea-weed and of the club-mosses that
grow in wet places. Soon. however.
animals appeared. and the layers of
Siiurian rock are found in some places
to be entirely composed of the shells of
animals. Sometimes these shells are
very small. but some are larger than
those of any animal now in existence.
Nor is it by any means certain that
small animals were created first. Lit
tie and bic seem to have existed to-
gether. We find the shells of animals
so small as to be invisible, except un-
der the microscope, side by side with
shells four feet broad. The framework
of the tiniest creature which helped to
make up these layers of rock is ex-
tremely beautiful.
The little coral animals commenced
their busy career during this age, build
ing limestone reefs and making the
beautiful chain coral which can still be
seen on the limestone cliffs in the West
ern States. Another kind of animal,
related to the coral polyp, and called a
"crinoid," )" must have greatly added to
the beauty of the Silurian seas. We
find its remains in the shape of a curl
ously carved. six-sided body. From
each of five sides a lily-like arm was
sent off, and the animal was fastened
to the rock by a stem running from the
center of the sixth side. Prof Agassiz
called them ''Stone lilies"
Other LAYERS of rock are composed
wholly of the remains of queer animals
called trilobites." They belonged to
the same family as our Holsters, and
varied in size from one-siXth of an inch
to two feet in length. There were two
great depressions running lengthwise
in their bodies, which divided them
into three lobes. They had also the
same ring-like divisions running around
the body as are seen in Holsters. They
swan on their backs. and had the pow
er of rolling themselves into ball.
Probably this was done to defend
themselves against some foe. Many
were caught in this position when the
mud was changing into rock, and kept
for us to see. In other layers OF rock
are found fossils of different animals of
the lobster kind. Nothing like these
old animals are found now.
SO MANY mollusks-that is, soft ami
mails with hard shells, like the oysters
then swan in the waters, that this
age is sometimes called the Age of
Mollusks. They were of all sizes and
shapes. and there were millions and
millions of them. There was one, be-
longing to the same family as our nau-
titus, which was four feet across An
other resembled a nautilus unrolled.
1t was from ten to fifteen feet long, and
measured Il foot in breadth.
The remains of fishes are found, for
the first time, in some of the upper lay
ers belonging to this period In Wales.
in the land of the Silures, they claim to
have found one layer composed entire
" of fish-bones.
Now, there is something we must
Keep IN mind when we speak of re
mains in geology, or else we shall be
disappointed when we see these fossils
If you should ever break open stone
and have the great good fortune to find
in it the remains of a leaf. what would
those remains be like? A real leaf?
No, nothing but the impression of one
No wood-no pulp. Simply a picture
engraved on the hard rock. So, also,
with the remains OF n fish-no body, no
bones-only an impressions; but so true
one that geologists can tell even the
way it swan, and, in some cases, the
nature of its food! As you were told
before, these remains are called fossils
What a thrill of pleasure it must give
to find one yourself-to think that little
bit of world history has remained sealed
up in a rock for centuries, waiting for
you to find it.
SO far, then. as we have iourneyed in
our travels through the back ages, we
see world of water, with such plants
and animals as live in water 1t is
true that little patches of dry land ex-
isted. IT'S at the close of the first period;
and these had even been increased Il
little by the addition OF beaches. But
these bits of land were so small, COM
pared with vast expanse of ocean, that
we are justified in calling it a world
of water" 1t must have been very
thickly inhabited ''water-world." since
whole layers of rock were made from
the animals which swan in its depths
or padded On its sUrface.-Ieresa G..
Croft0n, IN ST. Nicholas.