I was able to mention, in a note, the discovery of a large
Labyrinthodont, with well-ossified vertebrae, in the Edinburgh coal-field.
Since that time eight or ten distinct genera of Labyrinthodonts have been
discovered in the Carboniferous rocks of England, Scotland, and Ireland,
not to mention the American forms described by Principal Dawson and
Professor Cope. So that, at the present time, the Labyrinthodont Fauna of
the Carboniferous rocks is more extensive and diversified than that of
the Trias, while its chief types, so far as osteology enables us to
judge, are quite as highly organised. Thus it is certain that a
comparatively highly organised vertebrate type, such as that of the
Labyrinthodonts, is capable of persisting, with no considerable change,
through the period represented by the vast deposits which constitute the
Carboniferous, the Permian, and the Triassic formations.

The very remarkable results which have been brought to light by the
sounding and dredging operations, which have been carried on with such
remarkable success by the expeditions sent out by our own, the American,
and the Swedish Governments, under the supervision of able naturalists,
have a bearing in the same direction. These investigations have
demonstrated the existence, at great depths in the ocean, of living
animals in some cases identical with, in others very similar to, those
which are found fossilised in the white chalk. The _Globigerinoe_,
Cyatholiths, Coccospheres, Discoliths in the one are absolutely identical
with those in the other; there are identical, or closely analogous,
species of Sponges, Echinoderms, and Brachiopods. Off the coast of
Portugal, there now lives a species of _Beryx_, which, doubtless, leaves
its bones and scales here and there in the Atlantic ooze, as its
predecessor left its spoils in the mud of the sea of the Cretaceous
epoch.

Many years ago[1] I ventured to speak of the Atlantic mud as "modern
chalk," and I know of no fact inconsistent with the view which Professor
Wyville Thomson has advocated, that the modern chalk is not only the
lineal descendant of the ancient chalk, but that it remains, so to speak,
in the possession of the ancestral estate; and that from the Cretaceous
period (if not much earlier) to the present day, the deep sea has covered
a large part of what is now the area of the Atlantic. But if
_Globigerina_, and _Terebratula caput-serpentis_ and _Beryx_, not to
mention other forms of ani