above the level of
the sea!

Some raised sea-beaches, and drift containing marine shells, which I
examined in 1843, between Limerick and Dublin, and which have been
traced over other parts of Ireland by different geologists, have
required an extension of the dark lines so as to divide that island into
several. In improving this part of my map I have been especially
indebted to the assistance of Mr. Oldham, who in 1843 announced to the
British Association at Cork the fact that at the period when the drift
or glacial beds were deposited, Ireland must have formed an archipelago
such as is here depicted. A considerable part of Scotland might also
have been represented in a similar manner as under water when the drift
originated.

A portion of Brittany is divided into islands, because it is known to be
covered with patches of marine tertiary strata chiefly miocene. When I
examined these in 1830 and 1843, I convinced myself that the sea must
have covered much larger areas than are now occupied by these small and
detached deposits. The former connection of the White Sea and the Gulf
of Finland is proved by the fact that a multitude of huge erratic blocks
extend over the intervening space, and a large portion of Norway,
Sweden, and Denmark, as well as Germany and Russia, are represented as
sea, on the same evidence, strengthened by the actual occurrence of
fossil sea-shells, of recent species, in the drift of various portions
of those countries. The submergence of considerable areas under large
bodies of fresh water, during the tertiary period, of which there are
many striking geological proofs in Auvergne, and elsewhere, has not been
expressed by ruled lines. They bear testimony to the former existence of
neighboring lands, and a certain elevation of the areas where they occur
above the level of the ocean; they are therefore left blank, together
with all the space that cannot be demonstrated to have been part of the
sea at some time or other, since the commencement of the Eocene epoch.

In compiling this map, which has been entirely recast since the first
edition, I have availed myself of the latest geological maps of the
British isles, and north of Europe; also of those published by the
government surveyors of France, MM. de Beaumont and Dufresnoy; the map
of Germany and part of Europe, by Von Dechen, and that of Italy by M.
Tchihatchoff (Berlin, 1842). Lastly, Sir R. Murchison's important map of
Russia, and the adjoining