exclusively marine; others amphibious: others were terrestrial, raging in savannahs and jungles, clothed with a tropi cal vegetation, or basking on the margins of estuaries, lakes, and rivers. Even the air was tenanted by flying lizards, under the dragon form of Pterodactyles. The earth was probably at that time too much covered with water, and those portions of land which had emerged above the surface, were too frequently agitated by earthquakes, inundations, and atmospheric irregularities, to be extensively occupied by any higher order of quadrupeds than reptiles.

As the history of these reptiles, and also that of the vegetable remains,* of the secondary formations, will be made a subject of distinct inquiry, it will here suffice to state, that the proofs of method and design in the adaptation of these extinct forms of organization to the varied circumstances and conditions of the earth's progressive stages of advancement, are similar to those we trace in the structure of living animal and vegetable bodies; in each case we argue that the existence of contrivances, adapted to produce definite and useful ends, implies the anterior existence and agency of creative intelligence.

• The vegetable remains of the secondary strata differ from those of the transition period, and are very rarely accumulated into beds of valuable coal. The imperfect coal of the Cleveland Moorlands near Whitby, on the coast of Yorkshire, and that of Brora in the county of Sutherland, occurs in the lower region of the oolite formation; that of Bückeberg in Nassau, is in the Wealdean formation, and is of superior quality.

2

CHAPTER IX.

Strata of the Tertiary Series.

THE Tertiary Series introduces a system of new phenomena, presenting formations in which the remains of animal `and vegetable life approach gradually nearer to species of our own epoch. The most striking feature of these formations consists in the repeated alternations of marine deposites, with those of fresh water (see Pl. 1, sect. 25, 26, 27, 28.)

We are indebted to Cuvier and Brongniart, for the first detailed account of the nature and relations of a very important portion of the tertiary strata, in their inestimable history of the deposites above the chalk near Paris. For a short time, these were supposed to be peculiar to that neighbourhood; farther observation has discovered them to be parts of a great series of general formations, extending largely over the whole world, and affording evidences of, at least, four distinct periods, in their order of succession, indicated by changes in the nature of the organic remains that are imbedded in them.*

Throughout all these periods, there seems to have been a continually increasing provision for the diffusion of animal life, and we have certain evidence of the character and

* In Vol. II. of his Principles of Geology, Mr. Lyell has given an interesting map, showing the extent of the surface of Europe, which has been covered by water since the commencement of the deposition of the ter tiary strata.

M. Boué, also, has published an instructive map, representing the manner in which central Europe was once divided into a series of separate basins, each maintaining, for a long time, the condition of a fresh-water lake; those which were subject to occasional irruptions of the sea, would, for a while, admit of the deposition of marine remains; the subsequent exclusiorr of the sea, and return to the condition of a fresh-water lake, would allow the same region to become the receptacle of the exuvæ of animals inhabiting fresh-water.-Synoptische Darstellung der Erdrinde. Hanau, 1827. The

numbers of the creatures that were permitted to enjoy it, in the multitude of shells and bones preserved in the strata that were deposited during each of the four epochs we are considering.

M. Deshayes and Mr. Lyell have recently proposed a fourfold division of the marine formations of the tertiary series, founded on the proportions which their fossil shells bear to marine shells of existing species. To these divisions Mr. Lyell has applied the terms Eocene, Miocene, Older Pliocene and Newer Pliocene; and has most ably illustrated their history in the third volume of his Principles of Geo-logy.

The term Eocene implies the commencement or dawn of the existing state of the animal creation; the strata of this series containing a very small proportion of shells referable to living species. The Calcaire Grossier of Paris, and the London clay, are familiar examples of this older tertiary, or Eocene formation.

The term Miocene implies that a minority, of fossil shells, in formations of this period, are of recent species. To this era are referred the fossil shells of Bordeaux, Turin, and Vienna.

In formations of the Older, and Newer Pliocene, taken together, the majority of the shells belongs to living species; the recent species in the newer, being much more abundant than in the older division..

To the Older Pliocene, belong the Sub-apennine marine formations, and the English Crag; and to the Newer Pliocene, the more recent marine deposites of Sicily, Ischia, and Tuscany.*

same map on a larger scale, appears in the second series of the Transac tions of the Linnean Society of Normandy.

In the Annals of Philosophy, 1823, the Rev. W. D. Conybeare published an admirable memoir, illustrative of a similar geological map of Europe.

* The total number of known fossil shells in the tertiary series is 3,036. Of these 1,238 are found in the Eocene; 1,021 in the Miocene; and 777 in the Older and Newer Pliocene divisions.

Alternating with these four great marine formations above the chalk, there intervenes a fourfold series of other strata, containing shells which show them to have been formed in fresh water, accompanied by the bones of many terrestrial and aquatic quadrupeds.

The greater number of shells, both in the fresh-water and marine formations of the tertiary series, are so nearly allied to existing genera, that we may conclude, the animals by which they were formed, to have discharged similar functions in the economy of nature, and to have been endowed with the same capacities of enjoyment as the cognate mullusks of living species. As the examination of these shells would disclose nearly the same arrangements and adaptations that prevail in living species, it will be more important to investigate the extinct genera of the higher orders of animals, which seem to have been constructed with a view to the temporary occupation of the earth, whilst the tertiary strata were in process of formation. Our globe was no longer tenanted by those gigantic reptiles, which had been its occupants during the secondary period; neither was it yet fit to receive the numerous tribes of terrestrial mammalia that are its actual inhabitants. A large proportion of the lands which had been raised above the sea, being covered with fresh water, was best adapted for the abode of fluviatile and lacustrine quadrupeds.

Our knowledge of these quadrupeds is derived solely from their fossil remains; and as these are found chiefly (but not exclusively*) in the fresh-water formations of the tertiary The numerical proportions of recent to extinct species may be thus expressed. In the

-Lyell's Geology, 4 Ed. vol. iii. p. 308.

* The remains of Palæotherium occur, though very rarely, in the Calcaire Grossier of Paris. The bones of other terrestrial mammalia, occur

series, it is to them principally that our present attention will be directed.

Mammalia of the Eocene Period.

In the first great fresh-water formation of the Eocene period, nearly fifty extinct species of mammalia have been discovered by Cuvier; the greater number of these belong to the following extinct genera, in the order Pachydermata,* viz., Palæotherium, Anoplotherium Lophiodon, Anthracotherium, Cheropotamus, Adapis (see Plates 3 and 4.†)

occasionally in the Miocene and Pliocene marine formations, e. g. in Touraine and in the Sub-apennines. These are derived from carcasses which, during these respective periods, were drifted into estuaries and

seas.

No remains of mammalia have yet been found in the Plastic clay for. mation next above the chalk; the admixture of fresh-water and marine shells in this formation seems to indicate that it was deposited in an estuary. Beds of fresh-water shells are interposed more than once between the marine strata of the Calcaire Grossier, which are placed next above the plastic clay.

* Cuvier's order Pachydermata, i. e. animals having thick skins, includes three subdivisions of Herbivora, of which the Elephant, Rhinoceros, and Horse are respectively examples.

The place of the genus Palæotherium (see Plates 3 and 4) is intermediate between the rhinoceros, the horse, and tapir. Eleven or twelve species have already been discovered; some as large as a rhinoceros, others varying from the size of a horse to that of a hog. The bones of the nose show that, like the tapir, they had a short fleshy trunk. These animals probably lived and died upon the margins of the then existing lakes and rivers, and their dead carcasses may have been drifted to the bottom in seasons of flood. Some perhaps retired into the water to die.

Anoplotherium.

Five species of Anoplotherium (see Plates 3, 4) have been found in the gypsum of the neighbourhood of Paris. The largest (A. Commune) being of the size of a dwarf ass, with a thick tail, equal in length to its body, and resembling that of an otter; its probable use was to assist the animal in swimming. Another (A. Medium) was of a size and form more nearly approaching the light and graceful character of the Gazelle; a third species was nearly of the size of a Hare.