The World Before the Deluge

Fig. iiS.— Meandrina Daedalaea. a, entire figure, reduceci; b, portion, natural size. (Recent Coral.)

altogether, and the Great Oolite, having first overlapped the Fullers* Earth, passes across the Inferior Oolite, and in its turn seems to lie on the Upper Lias with a regularity as perfect as if no formation in the neighbourhood came between them. In Yorkshire the changed type of the Inferior Oolite, the prevalence of sands, land-plants, and beds of coal, occur in such a manner as to leave no doubt of the presence of terrestrial surfaces on which the plants grew, and all these phenomena lead to the conclusion that various and considerable oscillations of level took place in the British area during the deposi-

tion of the strata, both of the Inferior Oolite and of the formations which immediately succeed it."*

The Inferior Oolite here alluded to is a thin bed of calcareous freestone, resting on, and sometimes replaced by yellow sand, which constitutes the passage-beds from the Liassic series. The Fullers* Earth clay lies between the limestones of the Inferior and Great Oolite, at the base of which last lies the Stonesfield slate — a slightly oolitic, shelly limestone, or flaggy and fissile sandstone, some six feet thick, rich in organic remains, and ranging through Oxfordshire towards the north-east, into Northamptonshire and Yorkshire. At Colley Weston, in Northamptonshire, fossils of Fecopteris polypo-dioides are found. In the Great Oolite formation, near Bath, are many corals, among which the Etmomia radiata is very conspicuous. The fossil is not unlike the existing brain-coral of the tropical seas (Fig. 1 1 8). The work of this coral seems to have been suddenly stopped by "an invasion," says Lyell, " of argillaceous matter, which probably put a sudden stop to the growth of Bradford Encrinites, and led to their preservation in marine strata."t The Cornbrash is, in general, a cream-coloured limestone, about forty feet thick, in the south-west of England, and occupying a considerable area in Dorsetshire and North Wilts, as at Cricklade, Malmesbury, and Chippenham, in the latter county. Tei'ebratula obovata is its characteristic shell, and Niideolites dimiadaris^ Lima gibbosa, and Avicula echinata occur constantly in great numbers. Wherever it occurs the Cornbrash affords a rich and fertile soil, well adapted for the growth of wheat, while the Forest Marble, as a soil, is generally poor. The Cornbrash passes downwards into the Forest Marble, and sometimes, as at Bradford, near Bath, is replaced by clay. This clay, called the Bradford clay, is almost wholly confined to the county of Wilts. Terebratula decussata is one of the most characteristic fossils, but the most common is the Apiocrinites or pear-shaped encrinite, whose remains in this clay are so perfectly preserved that the most minute articulations are often found in their natural positions. Plate XIX., p. 261 (Fig. i), represents an adult attached by a solid base to the rocky bottom on which it grew, whilst the smaller individuals show the Encrinite in its young state — one with arms expanded, the other with them closed. Ripple-marked slabs of fissile Forest Marble are used as a roofing-slate, and may be traced over a broad band of country in Wiltshire and Gloucestershire, separated from each other by thin seams of clay, in

• President's Address, by Professor A. C. Ramsay. Qtiart, Jour. Geol. Soc.^ 1864, vol. XX., p. 4, t "Elements of Geology," p. 400.

I

XVII.—Ideal Landscape of the Lower Oolite Period.

v/hich thf^ imdalatlng ridges of the sand are preserved, and even the footmarks of small Crustaceans are still visible.

On the opposite page (Plate XVII.) is represented an ideal landscape of the period of the Lower Oolite. On the shore are types of the vegetation of the period. The Zamifes, with large trunk covered with fan-like leaves, resembled in form and bearing the existing Zamias of tropical regions; a Pterophyllicm, with its stem covered from base to summit with its finely-cut feathery leaves; Conifers closely resembling our Cypress, and an arborescent Fern. What distinguishes this sub-period from that of the Lias is a group of magnificent trees, Paiidamis^ remarkable for their aerial roots, their long leaves, and globular fruit.

Upon one of the trees of this group the artist has placed the PhascolotJieriimi,, not very unlike to our Opossum. It was amongst the first of the Mammalia which appeared in the ancient world. The artist has here enlarged the dimensions of the animal in order to show its form. Let the reader reduce it in imagination one-sixth, for it was not larger than an ordinary-sized cat.

A Crocodile and the fleshless skeleton of the Ichthyosaurus remind us that Reptiles still occupied an important place in the animal creation. A few Insects, especially Dragon-flies, fly about in the air. Ammonites float on the surface of the waves, and the terrible Plesiosaurus, like a gigantic swan, swims about in the sea. The circular reef of coral, the work of ancient Polyps, foreshadows the atolls of the great ocean, for it was during the Jurassic period that the Polyps of the ancient world were most active in the production of coral-reefs and islets.

Middle Oolite.

The terrestrial flora of this age was composed of Ferns, Cycads, and Conifers. The first represented by the Pachypteris mic7-ophyIla^ the second by Zamites Moreana. Brachyphylliuii Moreanum and B. majus appear to have been the Conifers most characteristic of the period; fruits have also been found in the rocks of the period, which appear to belong to Palms, but this point is still obscure and doubtful. Numerous vestiges of the fauna which animated the period are also revealed in the rocks of this age. Certain hemjpterous insects appear on the earth for the first time, and the Bees among the Hymenoptera, Butterflies among the Lepidoptera, and Dragon-flies

among the Neuroptera. In the bosom of the ocean, or upon its banks, roamed the Ichthyosaurus, Ceteosatirus, Pterodaciylus crassirostris, and the Geosauriis; the latter being very imperfectly known.

The Ceteosaurus whose bones have been, discovered in the upper beds of the Great Oolite at Enslow Rocks, at the Kirtlington Railway Station, north of Oxford, and some other places, was a species of Crocodile nearly resembhng the modern Gavial or Crocodile of the Ganges. This huge whale-like reptile has been described by Professor John Phillips as unmatched in size and strength by any of the largest inhabitants of the Mesozoic land or sea — perhaps the largest animal that ever walked upon the earth. A full-grown Ceteosaurus must have been at least fifty feet long, ten feet high, and of a proportionate bulk. In its habits it was, probably, a marsh-loving or riverside animal, dwelling amidst filicene, cycadaceous, and coniferous shrubs and trees full of insects and small mammalia. The one small and imperfect tooth which has been found resembles that of Iguanodon more than of any other reptile; and it seems probable that the Ceteosaurus was nourished by vegetable food, which abounded in the vicinity of its haunts, and was not obliged to contend with the Megalosaurus for a scanty supply of more stimulating diet.^

Another reptile allied to the Pterodactyle lived in this epoch — the Ra77iphorynchus, distinguished from the Pterodactyle by a long tail. The imprints which this curious animal has left upon the sandstone of the period are impressions of its feet and the linear furrow made by its tail. Like the Pterodactyle, the Ramphorynchus, which was about the size of a crow, could not precisely fly, but, aided by the wing (a sort of natural parachute formed by the membrane connecting the fingers with the body), it could throw itself from a height upon its' prey.

Fig. 119 represents a restoration of this animal. The footprints in the soil are in imitation of those which accompany the remains of the Ramphorynchus in the Oolitic rocks, and they show the imprints of the anterior and posterior feet and also the marks made by the tail.

This tail was very long, far surpassing in length the rest of the vertebral column, and consisting of more than thirty vertebrae — which were at first short, but rapidly elongate, retain their length for a considerable distance, and then gradually diminish in size.

Another genus of Reptiles appears in the Middle Oolite, of which we have had a glimpse in the Lias and Great Oolite of the preceding section. This is the Teleosaurus^ which the recent investigations of

** For a full account of the Ceteosaurus, see " The Geology of the Thames Valley," by Prof. John Phillips, F.R.S. 1871.

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XVIII.—Ideal landscape of the Middle Oolitic Period.

MIDDLE OOLITE.

M. E. Deslongchamps allow of re-construction. The Teleosaurus enables us to form a pretty exact idea of these Crocodiles of the ancient seas — these cuirassed Reptiles, which the German geologist Cotta describes as " the great barons of the kingdom of Neptune, armed to the teeth and clothed in an impenetrable panoply; the true filibusters of the primitive seas." The Teleosaurus resembled the Gavials of India. The former inhabited the banks of rivers, perhaps the sea itself; they were

Fig. 119.— Ramphorynchus restored. One-quarter natural size.

longer, more slender, and more active than the living species; tney were about thirty feet in length, of which the head may be from three to four feet, with their enormous jaws sometimes with an opening of six feet, through which they could engulf, in the depths of their enormous throat, animals of considerable size.

The Teleosaurus cadomensis is represented on the opposite page (Plate XVIII.), after the sketch of M. E. Deslongchamps, carrying from the sea in its mouth a Geoteuthis, a species of Calamary of the Oolitic epoch. This creature was coated with a cuirass both on the .back and belly. In order to show this peculiarity, a living individual is represented on the shore, and a dead one is floating on its back in shallow water, leaving the ventral cuirass exposed.

Behind the Teleosaurus cadomensis in the engraving, another Saurian, the Hylcsosaurus, is represented, which makes its appearance R 2

in the Cretaceous epoch. We have here adopted the restoration which has been so ably executed by Mr. Waterhouse Hawkins, at the Crystal Palace, Sydenham.

Besides the numerous Fishes with which the Oolitic seas swarmed, they contained some Crustaceans, Cirripedes, and various genera of Mollusca and Zoophytes. Eryoii arctiformis, represented in Fig. 119, belongs to the class of Crustaceans, of which the spiny lobster is the type. Among the Mollusca were some Ammonites, Belemnites, and Oysters, of which many hundred species have been described. Of

Fig. 121. — Perfect Ammonite.

these we may mention Afumojiites refradus^ A. Jason and A. cordatus, Ostrca dilataia, Tereh-aiula diphya^ Diceras arietena^ Belemnites has-tatus, and B. Fuzosianus. In some of the finely-laminated clays the Ammonites are very perfect, but somewhat compressed, with the outer lip or margin of the aperture entire (Fig. 120). Similar prolongations have been noticed in Belemnites found by Dr. Mantell in the Oxford Clay, near Chippenham. Among the Echinoderms, Cidaris glandifetus^ Apiocrinus Roissy-anus, and A. rotundus, the graceful Saccocoma pcctinata^ Millericrinns nodotiamcs^ Comatula costata, and Hemicidaris crcnularis may be mentioned Apiocrinites; 7'otundus^ figured in Plate XIX., is a reduced restoiation: i, being expanded j a, closed; 3, a cross section of the