The Silurian epoch has been referred by Elie de Beaumont to the
system of upheaval called by him the system of Westmoreland and
Hundsrueck,--again merely in reference to the spots at which these
upheavals were first studied, the centres, as it were, from which the
investigations spread. But in their geological significance they indicate
all the oscillations and disturbances of the soil throughout the region
over which the Silurian deposits have been traced in Europe. The Devonian
epoch added greatly to the outlines of the Belgian island. To it belongs
the region of the Ardennes, lying between France and Belgium, the
Eifelgebirge, and a new disturbance of the Vosges, by which that region
was also extended. The island of Bretagne was greatly increased by the
Devonian deposits, and Bohemia also gained in dimensions, while the
central plateau of France remained much the same as before. The changes of
the Devonian epoch are traced by Elie de Beaumont to a system of upheavals
called the Ballons of the Vosges and of Normandy,--so called from the
rounded, balloon-like domes characteristic of the mountains of that time.
To the Carboniferous epoch belong the mountain-systems of Forey, (to the
west of Lyons,) of the North of England, and of the Netherlands. These
three systems of upheaval have also been traced by Elie de Beaumont; and
in the depressions formed between their elevations we find the coal-basins
of Central France, of England, and of Germany. During all these epochs, in
Europe as in America, every such dislocation of the surface was attended
by a change in the animal creation.

If we take now a general view of the aspect of Europe at the close of the
Carboniferous epoch, we shall see that the large island of Scandinavia is
completed, while the islands of Bohemia and Belgium have approached each
other by their gradual increase till they are divided only by a
comparatively narrow channel. The island of Belgium, that of Bretagne, and
that of the central plateau of France, form together a triangle, of which
the plateau is the lowest point, while Belgium and Bretagne form the other
two corners. Between the plateau and Belgium flows a channel, which we may
call the Burgundian channel, since it covers old Burgundy; between the
plateau and Bretagne is another channel, which from its position we may
call the Bordeaux channel. The space inclosed between these three masses
of land is filled by open sea. To trace the gradual closing