In France, we not only find the shells of the French coast, but also such as have never been seen in those seas. Some philosophers assert, that the quantity of these foreign petrified shells is much greater than those of our climate; but I think this opinion unfounded; for, independent of the shell-fish which inhabit the bottom of the sea, and are seldom brought up by the fishermen, and which consequently may be looked on as foreigners, although they exist in our seas, I see, by comparing the petrifactions with the living analagous animals,

there are more of those of our coasts than of others: for example, most of the cockles, muscles, oysters, ear-shells, limpets, nautili, stars, tubulites, corals, madrepores, &c. found in so many places, are certainly the productions of our seas; and though a great number appear which are foreign or unknown, the cornu ammonis, the lapides juduica, &c. yet I am convinced, from repeated observations, that the number of these kinds is small in comparison with the shells of our own coasts: besides, what composes the bottom of almost all our marble and lime-stone but madrepores, astroites, and all those other productions which are formed by sea insects, and formerly called marine plants? Shells, however abundant, form only a small part of these productions, many of which originate in our seas, and particularly in the Mediterranean.

The Red sea produces corals, madrepores, and marine plants in the greatest abundance: no part furnishes a greater variety than the port of Tor; in calm weather so great a quantity present themselves, that the bottom of the sea resembles a forest; some of the branched madrepores are eight or ten feet high. In the Mediterranean sea, at Marseilles, near the

coasts of Italy and Sicily; in most of the gulphs of the ocean, around islands, on banks, and in all temperate climates, where the sea is but of a moderate depth, they are very common.

M. Peyssonel was the first who discovered that corals, madrepores, &c. owed their origin to animals, and were not plants as had been supposed. The observation of M. Peyssonel was a long time doubted; some naturalists, at first, rejected it with a kind of disdain, nevertheless they have been obliged since to acknowledge its truth, and the whole world is at length satisfied that these formerly supposed marine plants, are nothing but hives or cells formed by insects, in which they live as fish do in their shells. These bodies were, at first, placed in the class of minerals, then passed into that of vegetables, and now remain fixed in that of animals, the genuine operations of which they must ever be considered.

There are shell-fish which live at the bottom of the sea, and which are never cast on the shore; authors call them Pelogiæ, to distinguish them from the others which they call Litterales. It is to be supposed the cornu ammonis, and some other kinds that are only found

in a petrified state, belong to the former, and that they were filled with the stony sediment in the very places they are found. There might also have been certain animals, whose species are perished, and of which number this shell-fish might be ranked. The extraordinary fossil bones found in Siberia, Canada, Ireland, and many other places, seem to confirm this conjecture, for no animal has hitherto been discovered to whom such bones could belong, as they are, for the most part, of an enormous size.

These shells, according to Woodward, are met with from the top to the bottom of quarries, pits, and at the bottom of the deepest mines of Hungary. And Mr. Ray assures us, they are found a thousand feet deep in the rocks which border the isle of Calda, and in Pembrokeshire in England.

Shells are not only found in a petrified state, at great depths, and at the tops of the highest mountains, but there are some met with in their natural condition, and which have the gloss, colours, and lightness of sea-shells; and to convince ourselves entirely of this matter, we have only to compare them with those found on the sea shores. A slight examination will prove

that these fossil and petrified shells are the same as those of the sea; they are marked with the same articulations and in the glossopetri, and other teeth of fishes, which are sometimes found adhering to the jaw-bone, the teeth of the fish are remarked to be smooth and worn at the extremities, and that they have been made use of when the animals were alive.