had their representatives in Europe during this period. The prevailing types of quadrupeds were thick-skinned— Pachyderms-and cud-chewing-Ruminants. The hog and the horse began to exist in the middle of the Tertiary; and somewhat later appear, either in Europe or Asia, the cat, dog, weasel, hare, mink, hyena, camel, antelope, muskdeer, sheep, and ox-of the latter, several species. The Sivatherium was an elephantine stag, having four horns and probably a long proboscis. It is supposed to have had the bulk of an elephant, and greater height. This monster dwelt in southeastern Asia. Many other genera, quite distinct from existing forms, have had their former existence disclosed by the patient researches of the comparative anatomist. America was also a range of gigantic quadrupeds, while the adjacent seas were the abode of mammalian forms allied to the whale. Of these, the one best known is the Zeuglodon, whose bones are scattered over portions of the cotton-lands of Mississippi, Alabama, Georgia, and South Carolina. It is a striking sight to stumble over vertebræ a foot and a half long and a foot in diameter, or to see them plowed up from the black soil where they had been mouldering ever since that soil was a sea-bottom. Yet these bones were once so numerous in Southern Alabama that they were gathered and burned for lime, and laid in walls for fences. I have myself seen them used for andirons, and for building the steps of a stile over the dooryard fence. This animal was about seventy feet in length. The skeleton on exhibition in Wood's Museum, at Chicago, is for the most part a genuine representation of the framework of this Tertiary, alligator-like whale. Some of the vertebræ were wanting in this specimen; and in the attempt to restore the missing parts, the paleo-artist has possibly exceeded the bounds of truth, and given us a skeleton of greater length than the facts justify. After a personal and critical examination of the specimen, however, I feel bound to say that this prodigiously elongated creature, that visitors have so long seen coiled about one of the apartments of the museum, is as near a representation of the truth of nature as is likely to be attained. The skeleton possesses one hundred and eighteen vertebræ, of which ninety-one are genuine, and twenty-one factitious. The neck embraces six vertebræ. There are thirty-six pairs of ribs. The cranium is six feet long; the jaws are armed each with five grinding teeth on each side, preceded by two premolars and one incisor on each side of the middle. The epiphyses of the vertebræ-that is, their detached extremities-being unconsolidated with the bodies of the vertebræ, prove that the individual was still immature. examination was kindly authorized by Col. Wood, the proprietor. We are indebted to Dr. Koch, of St. Louis, for the first restoration of the Zeuglodon, a specimen of which was exhibited, a number of years ago, under the name of Hydrarchos, or Water-king, in Barnum's Museum in New York. This Far toward the northwest, on the tributaries of the Upper Missouri, were the cemeteries of American quadrupeds. The shores of the great inland seas already described seem to have been the favorite haunts of the dominant tribes of the continent, while swarms of humbler creatures bathed in their waters, or burrowed in the mud at the bottom. At first these waters possessed all the saltness of the sea of which they were the residuum; but, by degrees, the perpetual drainage, replaced only by fresh waters from the clouds, changed them first to a brackish, and then to a fresh condition. This progressive change is shown by the varying nature of the fossil remains imbedded in the sediments. At the bottom we find the relics of marine animals; in the middle, the vestiges of brackish-water life; and in the last deposits, only relics of fresh waters mingled with washings from the land. On the White River, in the Territory of Dakotah, in the region where it approaches nearest to the Big Cheyenne, are the Mauvaises Terres, or Bad Lands, where Nature seems to have collected together the relics of a geological age, and buried them in one vast sepulchre. The country to the west and southwest of Fort Pierre, for some hundreds of miles, is an elevated, gently undulating prairie, through which the streams have cut deep gorges for their passage to the larger rivers. It is a vast basin filled with the still horizontal and semi-indurated sediments of an inland sea. The wear of the weather has left many deep scars on the face of the country, and the Bad Lands present us with the mere ruins of a formation which was once continuous. The whole country is treeless and desolate. The soil beneath the feet of the traveler conceals the bones of the numerous populations which enjoyed existence in the earlier Tertiary epochs. The whole scene. has the air of the domain of death and solitude. On catching a glimpse of the Bad Lands proper, a most impressive exhibition presents itself. Here, in the surface of a vast plain, is a sunken area thirty miles wide and ninety miles long (Fig. 78). From the bottom of this sunken plain rise domes, and pinnacles, and monuments, and massive walls, which persuade the traveler that he is about to witness the movements and listen to the hum of a vast city. In the language of Dr. Evans-an eminent geologist who almost. "dwelt among the tombs" of the ancient world, as they lie stretched out from the Mississippi to the Pacific shores"these rocky piles, in their endless succession, assume the appearance of massive artificial structures, decked out with all the accessories of buttress and turret, arched doorway and clustered shaft, pinnacle, and finial, and tapering spire." On a nearer approach the illusion reluctantly vanishes, and all the fancied architecture is resolved into piles of hardened clay and sand. These rise from the bottom of the vale to the height of fifty, one hundred, and two hundred feet, showing along their vertical or sloping sides the varied courses of masonry of which they are composed. In the hundreds of towers and isolated masses that rise from this vale of solitude, the order of the courses is the same; and this agrees with the arrangement in the solid walls which circumscribe the valley. A thousand storms have washed the slopes, and furrowed them into the similitude of fluted shafts and clustered columns, which, at the top, bear sometimes a brown entablature of overhanging grass, or continue upward into tower and minaret. The bottom of the vale is an earth of chalky whiteness, baked by the sun, and utterly destitute of vegetation. The water which oozes out of the foundation-wall of the prairie is brackish and unpalatable. In winter, the wind and snow rush. through the lanes and corridors of this city of the dead in eddying whirls, while the withered grasses and the voiceless and motionless solitude, together with the relentless frost and never-tiring storm, make the place the realization of utter bleakness and desolation. In summer the scorching sun literally bakes the clays which have been kneaded by the frosts and thaws of spring, and the daring explorer of the scene finds no tree or shrub to shelter him from the fervid rays poured down from above, and reflected from the white walls which tower around him, and the white floor which almost blisters his feet. But the most impressive feature of the scene is the multitude of fossil bones which appear built into the massive masonry of this mimic architecture. The wearing and |