elongs to the Palaeozoic or Primary age, I am
convinced--and this conviction grows upon me constantly as I free myself
from old prepossessions and bias on the subject--that with the
Carboniferous epoch we have the opening of the Secondary age in the
history of the world. A more intimate acquaintance with organic remains
has shown me that there is a closer relation between the character of the
animal and vegetable world of the Carboniferous epoch, as compared with
that of the Permian and Triassic epochs, than between that of the
Carboniferous epoch and any preceding one. Neither do I see any reason for
separating it from the others as a distinct age. The plants as well as the
animals of the two subsequent epochs seem to me to show, on the contrary,
the same pervading character, indicating that the Carboniferous epoch
makes an integral part of that great division which I have characterized
as the Secondary age.

Within the Periods there is a still more limited kind of geological
division, founded upon the special character of local deposits. These I
would call geological Formations, indicating concrete local deposits,
having no cosmic character, but circumscribed within comparatively narrow
areas, as distinguished from the other terms, Ages, Epochs, Periods, which
have a more universal meaning, and are, as it were, cosmopolitan in their
application. Let me illustrate my meaning by some formations of the
present time. The accumulations along the coast of Florida are composed
chiefly of coral sand, mixed of course with the remains of the animals
belonging to that locality; those along the coast of the Southern States
consist principally of loam, which the rivers bring down from their swamps
and low, muddy grounds; those upon the shores of the Middle States are
made up of clay from the disintegration of the eastern slopes of the
Alleghanies; while those farther north, along our own coast, are mostly
formed of sand from the New-England granites. Such deposits are the local
work of one period, containing the organic remains belonging to the time
and place. From the geological point of view, I would call them
Formations; from the naturalist's point of view, I would call them
Zooelogical Provinces.

Of course, in urging the application of these names, I do not intend to
assume any dictatorship in the matter of geological nomenclature. But I do
feel very strongly the confusion arising from an indiscriminate use of
terms, and tha