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wards it. But there is the whirr of wings heard overhead, and lo! a monster descends, and the little mammal starts back into its hole. 'Tis a winged dragon of the Oolite, a carnivorous reptile, keen of eye and sharp of tooth, and that to the head and jaws of the crocodile adds the neck of a bird, the tail of an ordinary mammal, and that floats through the air on leathern wings resembling those of the great vampire bat. We have seen, in the minute, rat-like creature, one of the two known mammals of this vast land of the Oolite, the insect-eating Amphitherium; and in the flying reptile, one of its strangely organized Pterodactyls.

But hark! what sounds are these? Tramp, tramp, tramp, -crash, crash. Tree-fern and club-moss, cycas and zamia, yield to the force and momentum of some immense reptile, and the colossal Iguanodon breaks through. He is tall as the tallest elephant, but from tail to snout greatly more than twice as long; bears, like the rhinoceros, a short horn on his snout; and has his jaws thickly implanted with saw-like teeth. But, though formidable from his great weight and strength, he possesses the comparative inoffensiveness of the herbivorous animals; and, with no desire to attack, and no necessity to defend, he moves slowly onward, deliberately munching, as he passes, the succulent stems of the cycadaceæ. The sun is fast sinking, and, as the light thickens, the reaches of the neighbouring river display their frequent dimples, and ever and anon long scaly backs are raised over its surface. Its numerous crocodileans are astir; and now they quit the stream, and we see its thick hedge-like lines of equisetaceæ open and again close, as they rustle through, to scour, in quest of prey, the dank meadows that line its banks. There are tortoises that will this evening find their protecting armour of carapace and plastron all too weak, and close their long lives of centuries. And now we saunter downwards to the shore, and see the ground-swell breaking white in the calm against ridges of coral scarce less white. The

shores are strewed with shells of pearl,—the whorled Ammonite and the Nautilus; and amid the gleam of ganoidal scales, reflected from the green depths beyond, we may see the phosphoric trail of the Belemnite, and its path is over shells of strange form and name,—the sedentary Gryphæa, the Perna, and the Plagiostoma.

A snake-like form, sur

But lo! yet another monster. mounted by a crocodilean head, rises high out of the water within yonder coral ledge, and the fiery sinister eyes peer inquiringly round, as if in quest of prey. The body is but dimly seen; but it is short and bulky compared with the swan-like neck, and mounted on paddles instead of limbs; so that the entire creature, wholly unlike anything which now exists, has been likened to a boa-constrictor threaded through the body of a turtle. We have looked upon the Plesiosaurus. And now outside the ledge there is a huge crocodilean head raised; and a monstrous eye, huger than that of any other living creature,—for it measures a full foot across,-glares upon the slimmer and less powerful reptile, and in an instant the long neck and small head disappear. That monster of the immense eye,--an eye so constructed that its focus can be altered at will, and made to comprise either near or distant objects, and the organ itself adapted either to examine microscopically or to explore as a telescope, is another bepaddled reptile of the sea, the Ichthyosaurus or fish-lizard. But the night comes on, and the shadows of the woods and rocks deepen: there are uncouth sounds along the beach and in the forest; and new monsters of yet stranger shape are dimly discovered moving amid the uncertain gloom. Reptiles, reptiles, reptiles,-flying, swimming, waddling, walking;—the age is that of the cold-blooded, ungenial reptile; and, save in the dwarf and inferior forms of the marsupials and insectivora, not one of the honest mammals has yet appeared. And now the moon rises in clouded majesty; and now her red wake

brightens in one long strip the dark sea; and we may mark where the Cetiosaurus, a sort of reptilian whale, comes into view as it crosses the lighted tract, and is straightway lost in the gloom. But the night grows dangerous, and these monster-haunted woods were not planted for man. Let us return then to the safer and better furnished world of the present time, and to our secure and quiet homes.

LECTURE FIFTH.

The Lias of the Hill of Eathie-The Beauty of its Shores-Its Deposits, how formed Their Animal Organisms indicative of successive Platforms of Existences-The Laws of Generation and of Death-The Triassic System-Its Economic and Geographic Importance-Animal Footprints, but no Fossil Organisms, found in it-The Science of Ichnology originated in this fact-Illustrated by the appearance of the Compensation Pond, near Edinburgh, in 1842-The Phenomena indicated by the Footprints in the Triassic System-The Triassic and Permian Systems once regarded as one, under the name of the New Red Sandstone-The Coal Measures in Scotland next in order of Succession to the Triassic System-Differences in the Organisms of the two Systems-Extent of the Coal Measures of Scotland-Their Scenic Peculiarities-Ancient Flora of the Carboniferous Period-Its Fauna-Its Reptiles and Reptile Fishes-The other Organisms of the Period-Great Depth of the System-The Processes by which during countless Ages it had been formed.

THE Lias forms, as I have already had occasion to remark, the base of the great Oolitic system. I dealt in my last address with the productions, vegetable and animal, of those long ages of the world's history which the various deposits of this system represent, and attempted a restoration of some of its more striking scenes, as they must have existed of old in what is now Scotland. But in glancing once more at the Lias, we must pass from the living to the dead, from the vital myriads that once were, to the cemetery that contains their remains. I shall select as my example a single Liassic deposit of Scotland, but in several respects one of the most remarkable,—that of Eathie, on the shores of the Moray Firth, about four miles from the town of Cromarty. And in visiting it in its character as a great burial-ground, the final resting-place, not only of perished individuals, but also of extinct tribes and races, and in scanning its strangely sculptured monuments, roughened with

hieroglyphics, to which living nature furnishes the key, we may perhaps be permitted to indulge in some of those reflections which so naturally suggest themselves in solitary churchyards, or among the tombs of the ancient dead.

The hill of Eathie is a picturesque eminence of granitic gneiss, largely mixed with beds of hornblende schist, which extends, in a long precipitous ridge, some five or six hundred feet in height, along the northern side of the Moray Firth, and forms one of a primary chain of hills, which, in their upheaval, uptilted deposits of the Lias and Oolite. The deposit which the hill of Eathie disturbed is exclusively a Liassic one: the upturned edge of the base of the formation rests against the bottom of the hill; and we may trace the edges of its various upper deposits for several hundred feet outwards, bed above bed, until, apparently near the top of the formation, we lose them in the sea. There is a wild beauty on the shores of Eathie. A selvage of comparatively level ground, that occupies the space between the rocky beach and an inflection of the hill, seems embosomed in solitude; the naked scaurs and furze-covered slopes, where the fox and the badger breed, interpose their dizzy fence between it and the inhabited portions of the country above; while the rough unfrequented shore and wide-spreading sea form the secluding barriers below. The only human dwellings visible are the minute specks of white that look out in the sunshine from the dim and diluted blue of the opposite coast; and we may see the lonely firth broadening and widening as it recedes from the eye, and opens to the ocean in a direction so uninterrupted by land, that the waves, which, when the wind blows from the keen north, first begin to break on the distant headlands, and then come running up the coast, like white coursers, may have heaved their first undulating movements under the polar ice. The scene seems such a one as the anchorite might choose to wear out life in, far from the society of fellow-man; and we actually find, in exploring its

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