of a high standing in their division, and represented in the present day by the nautilus and the cuttle-fish, that we recognise in its fullest extent this extinct peculiarity of type and form. Its Brachipods, chiefly terebratulæ, not unfrequent in the Sutherland Oolites, and in the Lias of Cromarty and Skye, its periwinkles, whelks, aviculæ, pinnæ, pectens, oysters, and mussels, few of them wanting in any of our Scotch Liassic or Oolitic deposits, and many of them very abundant, though all specifically extinct, present us, though with a large admixture of strange and exotic forms, with many other forms with which, generically at least, we are familiar. But among the Cephalopods all is strange and unwonted; and their vast numbers—greater at this period of the world's history than in any former or any after time -have the effect of imparting their own unfamiliar character to the whole molluscan group of the Oolite. I need but refer to two families of these, the Belemnite family and the family of the Ammonites; both of them so remarkable, that they attracted in their rocks the notice of the untaught inhabitants of both England and Scotland, and excited their imagination to the point at which myths and fables are produced, long ere Geology existed as a name or was known as a science. The Belemnites are the old thunder-bolts of the north of Scotland, that, in virtue of their supposed descent from heaven, were deemed all potent in certain cases of bewitchment and the evil-eye; and the Ammonites are those charmed snakes of the mediæval legend,

'That each one

Was changed into a coil of stone,
When holy Hilda prayed.'

The exact affinities of the Belemnite family have formed a subject of controversy of late years among our highest authorities, men such as Professor Owen taking up one side, and men such as Dr. Mantell the other. But there

can be little doubt that it more nearly approached to our existing cuttle-fishes than to any other living animals; while there is no question that its contemporary the Ammonite is now most nearly represented, though of course only approximately, by the nautilus. The Belemnite existed in some of its species throughout all the formations of the great Secondary division, but neither during those of the Paleozoic nor yet of the Tertiary divisions; the Ammonite, on the other hand, though in an extreme and aberrant form, preceded it by several formations, but became extinct at the same time-neither Ammonite nor Belemnite outliving the deposition of the Chalk. The first great division of the animal kingdom, the vertebrata, was represented in Scotland during the Oolitic period by fishes and reptiles. Its fishes seem to have been restricted to two orders,-that placoid order to which the existing sharks belong, and that ganoid order, now wellnigh worn out in creation, to which the Lepidosteus of the North American lakes and rivers belongs, and to which I incidentally referred in connexion with the Lepidotus of the Weald. I have found in the island of Eigg beds of a limestone composed almost entirely of fossil shells, which were strewed over with the teeth of an extinct genus of sharks, the Hybodonts; and I have seen the dorsal spines of the same placoid division occasionally occurring among the Oolites of Sutherland and the Lias of Eathie. And scales, cerebral plates, and in some instances considerable portions of individuals of the ganoidal species, glittering in the enamel to which they owe their name, occur in all the Oolitic deposits of Scotland. Of our Scottish reptiles of the Oolite we have still a good deal to learn. I was fortunate enough in 1844 to find in a deposit of Eigg, and again at Helmsdale, in 1849, the remains of several of its more characteristic Enaliosaurs, or bepaddled reptiles of the sea; at Helmsdale I found vertebral joints of the Ichthyosaurus in a conglomerate lower in the Oolite; and in Eigg, in a

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stratum composed of littoral univalves, vertebral joints, phalanges, and portions of the humerus and of the pelvic arch of Plesiosaurus, together with the limb-bones of crocodileans, and fragments of the carapace of a tortoise. Previous, however, to even the earlier date of my discoveries, the tooth of a Saurian had been found in the Sutherlandshire Oolite by Mr. (now Sir Roderick) Murchison, and the limb-bone of a Chelonian with a sauroid vertebra, in the outlier of the Morayshire Weald at Linksfield. My collection, however, though still very inadequate in this department, contains, in quantity at least, and, I am disposed to think, in variety also, some eight or ten times more of the reptilian remains of Scotland, during the Secondary ages, than all the other collections of the kingdom. They at least serve to demonstrate that the Oolitic period in what is now our country, was, as in England and on the Continent, a period of huge and monstrous reptiles,-that the bepaddled Enaliosaurs, the strange reptilian predecessors of the Cetacea, haunted our seas in at least two of their generic forms,— that of the Ichthyosaur and that of the Plesiosaur; that our rivers were frequented by formidable crocodiles; and that tortoises of various perished species lived in our lakes and marshes, or, according to their natures, disported on the drier grounds. Nor is it probable that the other reptilian monsters of the time, the contemporaries of these creatures in England, would have been wanting here. We may safely infer that flocks of Pterodactyles,-reptiles mounted on batlike wings, and as wild and monstrous in aspect and proportion as romancer of the olden time ever feigned,— fluttered through the tall pine-forests, or perched on the cycadeæ and the tree-ferns; that the colossal Iguanodon and gigantic Hylæosaurus browsed on the succulent equisetacea of the low meadows; that the minute Amphitherium, an insectivorous mammal of the period, lodged among the ferns on the drier grounds, where extinct grass

hoppers chirped throughout the long bright summer, and antique coleoptera burrowed in the sand; and that far off at sea there were moments when the sun gleamed bright on the polished sides of the enormous Cetiosaurus, as it rose from the bottom to breathe. But I must close this part of my subject, the Scottish flora and fauna of the Oolite, -on which my narrow limits permit me, as you see, to touch at merely a few salient points, with two brief remarks:-First, So rich was its flora, that its remains formed on the east coast of Sutherland a coal, or rather lignite field, so considerable that it was wrought for greatly more than a century,-at one time to such effect, that during the twelve years which intervened between 1814 and 1826, no fewer than seventy thousand tons of coal were extracted from one pit. Second, The strange union which we find in the same beds of trees that seem to have languished under chill and severe skies, with plants, corals, and shells of a tropical or semi-tropical character, need not be regarded as charged with aught like conflicting evidence respecting the climatal conditions of the time. Climate has its zones marked out as definitely by thousands of feet on our hill-sides as by degrees of latitude on the surface of the globe; and if the Scotland of the Oolitic period was, as is probable, a mountainous country traversed by rivers, productions of an intertropical, and of even a semi-arctic, character, may have been not only produced within less than a day's journey of each other, but their remains may have been mingled by land-floods, as we find the huge corals of Helmsdale blent with its slow-growing pines, among the débris of some littoral bed. The poet's exquisite description of Lebanon suggests, I am disposed to think, the true reading of the enigma :—

'Like a glory the broad sun

Hangs over sainted Lebanon,

Whose head in wintry grandeur towers,

And whitens with eternal sleet;

While summer, in a vale of flowers,
Is sleeping rosy at his feet.'

The mere lists of the botanist and zoologist are in themselves repulsive and un-ideaed; and yet the existences which their arbitary signs represent are the vital marvels of creation,—the noble forests, fair shrubs, and delicate flowers, and the many-featured denizens of the animal world, so various in their forms, motions, and colours, and so wondrous in their structure and their instincts. I have been presenting you this evening with little else than a dry list of the Scottish productions of the Wealden and Oolitic ages,-a list necessarily imperfect, and all the more unsuggestive from the circumstance that, as myriads of ages had elapsed between the extinction of the races and families which its signs represent, and their first application as signs, so these signs, in their character as vocables, belong to languages as dead as the organisms themselves. The organisms were dead and buried, and converted into lignite or stone, long ages ere there was language enough in the world to furnish them with names; and now the dead has been employed to designate the dead,-dead languages to designate the remains of dead creations. Could we but see the productions of our country as they once really existed,—could we travel backwards into the vanished past, as we can descend into the strata that contain their remains, and walk out into the woods, or along the sea-shores of old Oolitic Scotland, we should be greeted by a succession of marvels strange beyond even the conceptions of the poet, or at least only equalled by the creations of him who, in his adventurous song, sent forth the Lady Una to wander over a fairy land of dreary wolds and trackless forests, whose caverns were haunts of dragons and satyrs, and its hills the abodes

'Of dreadful beasts, that, when they drew to hande,
Half-flying and half-floating, in their haste,

Did with their largeness measure o'er much lande,