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force continued unimpaired even subsequently to the formation of some tertiary deposits, those geologists who contend it is now in the wane must reason from a very limited number of facts indeed.

Both Mr. Poulett Scrope* and Dr. Daubenyt in their recent publications agree in considering that the effects produced at present by earthquakes and volcanos are at least analogous in kind, if inferior in degree, to those that have resulted from similar agents at remote æras. More than 170 volcanos are at present in activity on the land, even if separate orifices at a short distance from one another be reckoned as one volcano ; and there is reason to believe that there are at least as many, and probably a much greater number, beneath the sea—the power of which latter in throwing up islands and altering the bed of the sea is well known.

The chain of extinct volcanos described by the above mentioned authors in Auvergne, the latest of which became extinct before the period of any historical records; the streams of lava, which can be traced from their craters to the choked up vallies, and to the ancient courses of rivers thereby diverted into new channels ;these and many more phenomena raise the strongest presumption in favour of the great antiquity of some parts of the European continent. When we consider the deltas of large rivers, the strata at the bottom of freshwater lakes in Germany, Italy, and England, but, above all, the recent deposits at the bottom of the great American lakes Superior and Huron, inclosing shells of the very species now inhabiting those lakes and exposed to view in consequence of the subsidence of the water occasioned by the partial destruction of their barriers, we can affirm with certainty that modern freshwater deposits, of no inconsiderable thickness, far exceed in area the ancient freshwater formations, at present described. As to the scale on which submarine strata are now formed, we remain, of course, in comparative ignorance, but it is certainly more considera ble than has been supposed by many. Whether the coral reefs of the East Indian archipelago are built up from an unfathomable depth, as Flinders imagined, or are based on submarine volcanos, as Kotzebue and more modern writers suppose, we are at least certain, from the manner in which these zoophytes increase, and from the necessary accumulation of their broken fragments, that those aggregations of calcareous matter cannot be of slight depth, while we know that their superficial extent is immense. Captain King, in his late survey of Australia, sailed along a continued

Considerations on Volcanos, by G. Poulett Scrope, Esq. London. 1825. + See p. 2. Description of active and extinct Volcanos, by Charles Daubeny, M.D. London. 1826.

Letters to Professor Jameson, on the Volcanus of Auvergne, by Charles Daubeny,
M.D.F.R.S.
$ Dr. Bigsby in the Journal of Science, &c. No. 37. pp. 262, 263.
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us, but we shall treat of them only when they happen to throw light on the chief subject-matter of this Article. When controverted questions of interest present themselves, or generally received opinions chance to clash with our own, we shall discuss their merits without staying to inquire how far our digressions may sometimes be inconsistent with the Horatian maxim,- sit quodvis simplex duntaxat et unum.'

A very limited number of Mammiferous quadrupeds are natives of the British islands, or have inhabited them since we have any traditionary information. If we include the Bear, Wolf, and Beaver, now exterminated, and the Fallow Deer, which is supposed not to be indigenous, they may be comprised within twenty-three genera. But we have now discovered that this part of the earth was once peopled by many other animals of the same class. The horns of the Scandinavian,* and almost entire skeletons of the Irish elk, (the latter a species now unknown throughout the globe,) have been found buried in peat and marl, evidently of origin posterior to the last extensive revolution which modified the surface of the land. Besides these, in superficial loam and gravel, consisting of transported materials, and in caves and fissures of rocks, the remains of species belonging to at least fifteen distinct genera occur; some of thein identical with those still surviving in England, others being extinct species. Of these last, the remains of the Elephant, Rhinoceros, and Hippopotamus are very extensively distributed. Those of the Cave-bear and Cave-hyæna have been found in but a very few spots; but the bones of the hyæna already obtained must have belonged to several hundred'individuals. Remains of a Tiger and two species of Deer have been also found, but too inconsiderable in number to enable us at present to decide on their specific characters. In similar geological situations in other parts of Europe, where the existing viviparous quadrupeds do not greatly out-number those of England, there are found in company with the fossils above enumerated a species of mastodon, (a lost genus that bore some affinity to the elephant,) a small hippopotamus, three species of rhinoceros, a gigantic tapir, a camel,+ and several others. But we have not yet penetrated beyond the first boundaries of this new region of discovery. Even since the

very

recent publication of the third edition of M. Cuvier's Fossil Osteology, in which all the above were described, no less than thirty species of animals have been found in volcanic tufa in the department of

* Edinburgh Journal of Science, vol. v. p. 129.

+ Discovered near Montpelier by M. Marcel de Serres. Mém. de la Soc. Linn. de Paris. 1825.

Puy

respect to the general laws of co-existence and structure, and all that relates to the nature of their organs and their essential functions, they were the same as those of our own time.'*

But in oviparous quadrupeds, remarkable alike for their magnitude and organization, nature has, in ancient epochs, teemed throughout these latitudes with a prolific power not exerted at present even between the tropics. These quadrupeds occur in strata of far more ancient date than the viviparous class. They make their first appearance in England in the lias, where many skeletons are procured in so perfect a state that the most exact knowledge has been obtained of their structure. In the volume before us are two excellent papers, by Mr. Conybeare, on the osteological characters of the fossil genera Ichthyosaurus and Plesiosaurus, both first discovered and determined in this country. 'The Ichthyosaurus is an animal entirely sui generis ; possessing, bowever, sufficient analogies with the Saurian order to justify our referring it to that great natural division :-it holds an intermediate place between the crocodile and lacertæ,' Like the Cetacea- it was exclusively an inhabitant of the sea ; its eyes were of an enormous size, its neck short, its tail extremely long, its paddles broad and fat, and its whole frame admirably adapted for passing with rapidity through the water. Mr. Conybeare has ascertained four distinct species: one of these, I. communis, sometimes exceeds twenty feet in length; and I. platyodon was yet more gigantic.

The Plesiosaurus was still more extraordinary. Of this genus five species are ascertained. An almost entire skeleton of one of these--P. dolichoderus, found in lias at Lyme Regis in Dorsetshire, and now in the possession of the Duke of Buckingham, is figured in this volume. This specimen does not exceed eight or nine feet in length, but the same species sometimes attained the length of twenty feet. It was distinguished from all known oviparous and viviparous quadrupeds, by a thin slender neck, equalling or exceeding the body in length, and composed of above thirty vertebræ.

This great increase,' observes Mr. Congbeare,' of the number of joints in the neck is the more remarkable from the rigour with which nature appears in most cases to have enforced the law of a very limited number. In all quadrupedal animals, in all the mammalia, (excepting only the tridactyl sloths, which have nine,) the series is exactly seven ; and so strict is this rule, that even the short and stiff neck of the whale, and the long and flexible neck of the cameleopard are formed out of the same elementary number; the vertebræ in the former instance being extremely thin and anchylosed together, and in the latter greatly elongated. Rep

* Cuv. Oss. Foss. vol. iii. pp. 15. 255.

the largest of these equalled a rhinoceros in magnitude, others were of the sizes of the pig and the sheep, and the smallest was no larger than the hare.* Of the Lophiodon, a genus that also bore a considerable resemblance to the Tapir, more than twelve species have been determined; the largest of these was about the size of the rhinoceros, and the smallest about that of a lamb three months old. Of the extinct genus Anoplotherium, which differs extremely in anatomical character from any now known, six species are already ascertained :- the largest came near in size to the ass; another to the gazelle, which it is supposed to have rivalled in the elegance of its form; another did not exceed the hare in size, and some were still smaller. The species most frequently met with in the gypsum of Paris was about the height of a wild boar, but had nearly the proportions of the otter; it had a thick and long tail, and probably swam well and frequented the lakes, in the bottom of which its bones have been incrusted with the gypsum there deposited.'S Of the extent of these ancient lakes the geologist can still form some idea, when he has traced in his map the boundaries of strata replete with the remains of freshwater animals and plants. Of the genus Antracotherium, two species have been found, one of the size of a Rhinoceros, the other smaller: these were intermediate between the Palæotherium, Anoplotherium, and Hog. Of each of the genera Cheropotamus and Adapis, one species only is known, about the size of a rabbit. In the same formation with these herbivorous animals a few carnivorous ones are found; a Fox, a Gennet, a Bat, and a small Opossum, (a genus unknown till the discovery of America,) and some few others. Skeletons also of a dorinouse and a squirrel occur, besides the bones of birds, crocodiles, freshwater tortoises, and fish; nor are shells wanting. The whole of these are either of extinct genera or of unknown species.

The plants on which these large herbivorous animals were supported differed as widely as themselves from all known species. Palms, reeds, and

many

other kinds are met with in these strata, indicating upon the whole the vegetation not of tropical climates--as does the flora of our secondary formations and particularly of the coal—but rather such as now clothes the countries bordering on the Mediterranean.

No remains of the human species have been found with the above fossil animals, nor elsewhere in any stratum having pretensions to immemorial antiquity. It is nearly a century since Bishop Berkley remarked, that if Man had existed for so many

Cuv. Discours sur les Rev. p. 315, 316. 1825. † Ib. p. 319. Ib. p. 320.

Ib. p. 321.

ages

ages as some nations and some philosophers have maintained, gems, medals, and implements, in metal or stone, would have lasted entire, ' as the shells and stones of the primeval world are preserved down to our time;'* he might have added that human skeletons would have also attested the fact, for Cuvier has shown that there are strong grounds for believing these to be as little perishable in their nature as those of other animals. But the entire absence of all Quadrumana-guch as the durang-outang, ape, monkey, baboon, and many other genera—is a circumstance not less striking. The animals of this family are at present as numerous as other grand divisions of Mammalia, and in their osteological characters they approach much nearer to the human species than any others. They are almost exclusively confined at present to countries lying between the tropics, and never far exceed this limit;—but as the same may be said of the Elephant, Rhinoceros, Hippopotamus, Tapir, and other genera, as well as of the reptiles so abundant in a fossil state in Europe, some extinct species at least of the Quadrumana' might have been looked for. An opinion was entertained soon after the commencement of the study of organic remains, that in ascending from the lowest to the more recent strata, a gradual and progressive scale could be traced from the simplest forms of organization to those more complicated, ending at length in the class of animals most related to man. And such is still the general inference to be deduced from observed facts, though some recent exceptions to this rule are too well authenticated to justify an implicit reliance on such generalizations.

But what is most important with regard to the history of the above-mentioned lost race of quadrupeds, is the circumstance that both in the environs of Paris and in those of Orleans, as well as in Berri, and in a district not far from the Rhine, near Strasburgh, the strata inclosing them are again covered with marine deposits. A careful examination of the contents of these leaves no doubt that the sea returned and covered the land on which the animals had lived, and where the rivers and lakes were situated, in the beds of which their remains had been buried. To such an event M. Cuvier has attributed with great probability the annihilation of the quadrupeds then inhabiting the ancient continents. But to what known agents in nature can we ascribe such destructive catastrophes ? • The great winding sheets,' says Lord Bacon,

that bury all things in oblivion are two, deluges and earthquakes.'I That these two causes have in fact conspired in former

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