ety_, Vol. XXIV. p. 532.

[26] See Presidential Address in Sect. D. of British Association at
Plymouth, 1877.

[27] _Geological Magazine_, 1871, p. 426.

[28] In his lecture on _Geographical Evolution_ (which was published after
the greater part of this chapter had been written) Sir Archibald Geikie
expresses views in complete accordance with those here advocated. He
says:--"The next long era, the Cretaceous, was more remarkable for slow
accumulation of rock under the sea than for the formation of new land.
During that time the Atlantic sent its waters across the whole of Europe
and into Asia. But they were probably nowhere more than a few hundred feet
deep over the site of our continent, even at their deepest part. Upon their
bottom there gathered a vast mass of calcareous mud, composed in great part
of foraminifera, corals, echinoderms, and molluscs. Our English chalk,
which ranges across the north of France, Belgium, Denmark, and the north of
Germany, represents a portion of the deposits of that sea-floor." The
weighty authority of the Director-General of the Geological Survey may
perhaps cause some geologists to modify their views as to the deep-sea
origin of chalk, who would have treated any arguments advanced by myself as
not worthy of consideration.

[29] _Introduction and Succession of Vertebrate Life in America_, by
Professor O. C. Marsh. Reprinted from the _Popular Science Monthly_, March,
April, 1878.

[30] _Physical Geography and Geology of Great Britain_, 5th Ed. p. 61.

[31] Of late it has been the custom to quote the so-called "ridge" down the
centre of the Atlantic as indicating an extensive ancient land. Even
Professor Judd at one time adopted this view, speaking of the great belt of
Tertiary volcanoes "which extended through Greenland, Iceland, the Faroe
Islands, the Hebrides, Ireland, Central France, the Iberian Peninsula, the
Azores, Madeira, Canaries, Cape de Verde Islands, Ascension, St. Helena,
and Tristan d'Acunha, and which constituted as shown by the recent
soundings of H.M.S. _Challenger_ a mountain-range, comparable in its
extent, elevation, and volcanic character with the Andes of South America"
(_Geological Mag._ 1874, p. 71). On examining the diagram of the Atlantic
Ocean in the _Challenger Reports_, No. 7, a considerable part of this ridge
is found to be more than 1,900 fathoms deep, while the portion called the
"Connecting Ridge" seems to be due in part to the deposits carried out b