THE THIRD EPOCH. 319 CHAPTER XV. The Tertiary Period. "Yes! Where the huntsman winds his matin horn, Horace Smith. We are now to consider the last great epoch, called the tertiary period, commencing immediately after the deposit of the chalk, and ending with the appearance of man. The tertiary strata consist of a vast and varied series of deposits, fluviatile, lacrustine, marine and volcanic, but they are all deposited in hollows or depressions, usually of the chalk, and occasionally of the older rocks, and afford distinct evidence of important changes in the relative level of land and sea, during the period in which they were deposited, and they likewise show that volcanic agency was developed at this period on a vast and magnificent scale. From the remains entombed during this epoch, it is pretty evident that the climate of the ancient world was much milder than at present. Be this as it may, it is a fact indisputable, that not only the bones of hyenas, bears, lions, and tigers, are found in countries where now they could not live, but also several varieties of palms and pines; and even as far north as the 70° of latitude, the remains of the elephant and rhinoceros are found imbedded in the ice. During the tertiary epoch, the Ganoid and Placoid groups of fishes, so characteristic of the earlier deposits, were almost extinct, the latter class being represented by a few sharks and rays, while by far the greater number were allied to existing species, The remains of birds; skeletons, feathers, and even their eggs, are found in good preservation-they are allied to present existing species. On the island of New Zealand, an immense number of fossil bones of birds have been found; we have already alluded to one of these, the Dinornis, page 312; the beak of this bird was shaped like a cooper's adze, and admirably adapted for tearing up roots; they were, as Dr. Mantell remarks in a letter to Prof. Silliman, "glorious bipeds, some ten or twelve feet high." In the tertiary strata of the Paris basin, Cuvier found the remains of several thick skinned animals allied to the tapir, and of others forming a connecting link between the tapir and the ruminants, or animals chewing the cud-some of these were of very peculiar forms. A remarkable animal, characteristic of the middle tertiary period, was the Deinotherium, or terrible beast, figured in the engraving below This huge animal dwelt probably in marshes and swamps, and was nearly twenty feet long; the legs are supposed to have been nearly ten feet in length, the head was of proportional size, and furnished with two large tusks fixed in the lower jaw, which probably, served the purpose of pickaxes, to dig out the roots upon which it fed, and perhaps to anchor it by the side of the bank at night. In Russia and Siberia, remains of the elephant and rhinoceros have been found entombed in ice, together with birch trees, far beyond where even stinted bushes now grow. The tusks of the fossil elephants are found in the high hills above the sea level, in clay and sand frozen as hard as a rock, and increasing in abundance as we proceed north. For about a century they have been brought away in immense num bers, yet with no perceptible diminution of the stock; doubtless. many of these animals were drifted down towards the arctic seas by the immense rivers which flow northward into the icy ocean. The subjoined figure represents the skeleton of the celebrated elephant discovered by a Tungusian fisherman, in the year 1790, in the banks of a river in Siberia, in which it had been frozen up for ages. The skin of this animal was of a dark grey color, and covered with reddish wool. The two tusks, together, weighed three hundred and sixty pounds, and the head alone, four hundred and fourteen pounds; the flesh of this antediluvian was in such perfect preservation, that the dogs, white bears, wolves and foxes fed upon it. The eyes were well preserved, and the pupil in one of them could be distinguished. The fossil Siberian elephant differed but little from the one now inhabiting India, except in its wooly covering; its food was probably twigs and branches, in pursuit of which, herds of these gigantic quadrupeds probably migrated far north. The remains of elephants are very widely distributed; they are found in England and various parts of America; the teeth of the elephant may be readily distinguished from those of the mastodon, another large hebiverous animal belonging to this period, by a peculiar structure we will now describe. We here represent the teeth of the recent and fossil elephant; a the African, b the Indian or Asiatic, c the Siberian or fossil. In the first variety, (a) the enamel is arranged in lozenge-shaped figures, and in the second (b) in narrow transverse bands, very similar to the fossil species c; these teeth are composed of three different substances; the enamel, exhibited by the white lożenges or bands, and which extends quite through the tooth to the roots; the ivory inside of the lozenges, and the crusta petrosa or stony crust outside. The tooth of the mastodon represented below, consists of ivory and enamel only; the enamel being spread over the crown of the.tooth, its structure is similar to that of the hog and hippopotamus, fitted for bruising and masticating crude vegetables and roots. The bones and teeth of the mastodon äre found all over North America, and many entire skeletons have been exhumed, in some of which, the remains of branches and twigs undigested have been found. The remains of these animals are particularly abundant in those marshy tracts, abounding in salt and brackish waters called licks. The mastodon was not unlike the elephant, but was somewhat larger, and probably THE MEGATHERIUM. 323 fifuch more powerful. While in England and various parts of the eastern continent, the elephants were congregated in immiense numbers, and the plains of North America covered with herds of mastodons, another and more singular animal, allied to the sloth, lived in the forests of South America; we refer to the Megatherium, or great beast. In the museum at Madrid, there is a perfect skeleton of this animal, whose massive propor tions strikes the beholder with astonishment; it is represented in the wood-cut below, and the proportions will be recognized on comparing the figure with that of an ordinary sized man, drawn to the same scale. Its length is nineteen feet, breadth across the loins, six feet, and height, nine feet. The feet of the hind legs set at right angles, as in the bear; the heel projects behind, fifteen inches, and the toes, armed with long claws, about twice that distance forward so that a proper base is afforded for the support of the immense body. The teeth of the megatherium were constantly renewed. This apparently unwieldy animal is allied to the sloth, but differs from it in the immense strength and mas siveness of its posterior portions. It is supposed they fed upon the foliage of trees which they were enabled to uproot by their immense strength. This idea is confirmed from the fractures of the skull observed iu some of the specimens. Contemporary with the megatherium, were several other allied species, which ranged through the luxuriant forests of South America, while in England |