Page:South African Geology - Schwarz - 1912.djvu/136

beds of South Africa, from the Cape System upwards, are called the Neo-Afric Group; and those below the Cape System the Pre-Cape or Pal-Afric Group.

The systems in the Cape and Transvaal are not yet correlated; their parallelism in the Table means that they occupy about the same position. There are, in addition, many smaller systems which will be noticed in due course, but which are not included in the general Table.

Characteristic Organic Remains found in the Strata

Cainozoic.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Quaternary Man.					Flowering Plants.
		Tertiary Monkeys.		Nummulites.
Mesozoic.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Cretaceous Birds.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	Ammonites and Belemnites.
		Jurassic Mammals.
		Triassic.
Younger Palæozoic.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Permian Reptiles.					Land Plants.
		Carboniferous Amphibia Insects.			$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right\}\,}$	Trilobites.
		Devonian.
Older Palæozoic.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Silurian Fish.	$\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}$	Graptolites.
		Ordovician Corals.
		Cambrian Brachiopoda, Mollusca.

The organisms mentioned make their first appearance at the horizons indicated, and those in brackets are confined to the strata to which the particular bracket refers.

The general arrangement shows that the younger the beds the more highly organized are the remains of the animals or plants found in them; and, conversely, the older the beds the more primitive the type of organisms. There are two general facts which must be noted. In the first place, the first beds in which organic remains are found contain fossils of animals in an extremely high state of development. The Trilobites of the Cambrian are animals something like woodlice, though they lived in the sea, with well-developed eyes implying a brain, complicated legs, and generally showing that they must