164 GEOLOGY. 
measures. We find sea-weed, fine-leaved ferns, tall calamites, and reeds, - 
great pines with cones, tree-ferns, and palms like the modern fan palm. 
The animal remains are not nearly so numerous as in the coal rocks. 
There are sponges, corals, sea-urchins, and beautiful shells. We also find 
fishes like those of the Coal-measures, and the Permian is remarkable as 
the system where the ancient form of tail, in which the spine of the fish 
was continued into the upper lobe of the tail, becomes extinct, never to 
appear again. The reptiles of this system are numerous and perfectly 
developed, some of them being of gigantic form. Their footprints, in 
particular, are remarkably abundant and large, and from these alone, the 
whole animal has been constructed by learned men, the truth of their 
drawings being proved by subsequent discovery of the entire creature. 
Even pouched animals, like the kangaroo, are found in the American 
Permian, thus shewing a gradual but slow approach to modern life 
forms. 
Scenery of Period.—The Carboniferous Period was remarkable for the 
great activity of volcanic agents, but this period seems to have been com- 
paratively tranquil in this respect. The rivers carried.in their waters 
much iron, as they did in the Old Red Period; the seas appear to have 
been shallow, bearing in solution magnesia and \salt, while animal and 
vegetable life seems scarce, as compared with other epochs. From the 
existence of a rough conglomerate in the west of England, it has been ably 
argued that the greater part of the period was one of glacial action, with 
icebergs bearing blocks and rounded débris ; and if this was the case, we 
have a conclusive explanation of the scarcity of life during this period. 
VIII.—Triassic System. 
Description.—The upper part of the old system, known as the New Red 
Sandstone, has received the name Triassic, which means triple, from being 
found in Germany in three distinct groups, of which the first and third 
alone exist in Britain. 
The system contains sandstones of different colours, shales, and conglo- 
merates ; but the distinguishing product is rock-salt. This occurs in beds 
of from seventy to one hundred feet thick in Cheshire, whence we obtain 
salt for daily consumption. Salt-springs also abound in salt districts, being 
formed by the issuing of water through the salt rocks below. The Triassic 
rocks are found in patches in the British Isles, but extensively on the 
continent of Europe and in America. 
Organic Remains.—The organic remains are very scanty, especially when 
compared with the exuberance of life in eras before and after. Plants 
are rare both in number and species. We find horse-tails, calamites, 
and ferns. The gigantic trees of the Coal-measures no longer exist, 
