feet in height, and extending from New England to Alabama. Some of the folds of the Appalachian upheaval, according to the grand generalizations of the brothers. Rogers, were protruded with so abrupt a flexure, and to such a dizzy height, that they toppled over toward the west; while to the west of the principal axis of violence. the folds become gentler, and terminate in pleasant undulations of the surface. The Queen City of the West stands, perhaps, on the last of this series of undulations. Thus were the Appalachians brought into existence. Thus were the deep-seated beds of coal lifted above the general level of the land, and brought within the reach of moderate excavations, accompanied by the requisite conditions for natural drainage of the mines (Fig. 68).

Fig. 68. The North American Continent at the end of Paleozoic Time, or beginning of Mesozoic. (The dotted lines represent its present outlines; the broken lines the rivers.)

Subsequent geological agencies have greatly modified the primary result. The ocean has been permitted still again to sweep over the continent, and the crests of the folds and ridges have all been planed down, and the materials distributed over the intervening spaces, or worked up in the rock-building of later ages. Thus the original height of the Alleghanies has been much reduced. Thus the swell upon which the Queen City of the West is built has been worn off to the level of the adjacent areas; and thus the original limits of the great Carboniferous jungle have been very much restricted.

CHAPTER XV.

THE SCOUTS OF THE REPTILE HORDE.

EME

MPIRES rose upon the earth, and crumbled in succession to decay, a thousand ages before the foot of Adam had pressed the soil of the Garden of Eden. A series of dynasties flitted like shadows over the face of our planet, and disappeared beneath the dim horizon of the past, while the empire of man was but an idea dwelling in the Almighty Mind. Here were morning and evening, invigorating sunlight and cooling dew, softly-wooing breeze and fiercely-maddened tempest, springtime and autumn, weeping clouds and placid evening sky, Winter piping his melancholy song upon the withered reeds of Summer, oceansurges waging everlasting battle with the rocky shore, God alone spectator of the progress of the mighty work which was being accomplished. But there was life, and motion, and consciousness, and enjoyment, and death through all those dim and distant ages. Those dim and distant ages-how imagination halts, and faints, and falters in the effort to shoot back over the infinite stretch of years! Life was here, but without a voice, without a wing, without a footstep. The ignoble mollusc held dominion in the sea through all the morning twilight of animated existence.

The mute fish reared his empire on the ruins of that of the mollusc. In the middle Paleozoic ages this first and lowest form of vertebrate existence appeared in all the seas -not fishes clothed in horny scales like those which swarm in the waters of the human era, but fishes clad in coat of mail, bucklered aud helmeted with bony plates, and armed

with long and powerful spines, or, in a later age, with a fearful array of sharp and conical teeth. The dynasty of the fishes sprang up in that period when the limestones of Buffalo, in New York, and of Columbus, Sandusky, and Kelly's Island, in Ohio, were accumulating as sediments in the bottom of the sea; when Canada West was the ocean's bed, and the last crop of zoöphytes was growing upon it; when the beautiful island of Mackinac was a submarine plantation, and the embryo fastnesses of Old Fort Mackinac witnessed an onslaught and a massacre more bloody and destructive than that of 1761. The empire of the fishes waxed more powerful during the succeeding epochs, when the "black shales" of the West, and, later, the beautiful sandstones of Waverly and Cleveland, Ohio, were the ocean's bed, and hordes of marine forms roamed over the area of Southern New York, and nearly the whole of Michigan, Indiana, and Illinois. The Marshall epoch probably covers the latter part of the period of the Old Red Sandstone of Scotland, whose ichthyic populations have been so graphically described by the author of the "Asterolepis of Stromness."

The reign of the fishes was prolonged through the Car boniferous period; but the types which wielded the sceptre during the later ages of the empire assumed less questionable forms, and began to approach the external configuration of the fishes of our day. They were mostly clothed, however, with bony scales, and the backbone extended into the upper lobe of the tail, which was longer than the lower; or, what is probably a more correct view of this structure, the tail was supplied upon the under side with a supernumerary fin, the development of which deflected upward the true caudal fin-the tail of the sturgeon and the garpike. being as truly "homocercal" as that of the whitefish. It is sad to think of the ancient populousness and prowess of

these mail-clad fishes, and then turn to our own times and find them reduced to a few isolated, hated, and hunted species. The garpike or "billfish" (Lepidosteus), and the sturgeon (Acipenser), are the only surviving representatives of the royal families of the Carboniferous Age. In turn, the dynasty of the fishes was superseded by that of the reptiles.

It was impossible that air-breathers should inhabit the earth before the atmosphere became purified of the noxious gases which remained from the ancient igneous condition of the globe. The principal impurity-carbonic acid-was destined to be consumed by the demands of an abundant terrestrial vegetation. The latter part of the reign of fishes. was marked by the advent of multitudes of land-loving vegetable forms-the heralds of the close of the dominion of races whose element was the water. It was many ages after its first appearance before terrestrial vegetation became fully established. We know that here and there one of these stranger forms grew upon the shores of those seas which were the domain of the fish; and, falling down upon the beach, or borne along by river torrents, the decaying trunks were drifted seaward, and sunken among the sands which entombed the bodies of the royal families of the age. We know that the slight improvement in the condition of the atmosphere was responded to by the introduction of a few air-breathers of sluggish and imperfect respiration. The name of the oldest air-breathing animal at present known to have lived upon our earth is Telerpeton Elginense. Its remains have been found in the south of Scotland, in a yellow sandstone supposed to be of the same age as the Old Red Sandstone. The same rock has furnished some other remains, formerly supposed to be the vestiges of fishes, but now known to be the remains of reptiles; and geologists are not by any means of one accord in the opin