I have spoken especially of the inhabitants of the Jurassic sea lying between England and France, because it was there that were first found the remains of some of the most remarkable and largest Jurassic animals. But wherever these deposits have been investigated, the remains contained in them reveal the same organic character, though, of course, we find the land Reptiles only where there happen to have been marshes, the aquatic Saurians wherever large estuaries or bays gave them an opportunity of coming in near shore, so that their bones were preserved in the accumulations of mud or clay constantly collecting in such localities,--the Crustacea, Shells, or Sea-Urchins on the old sea-beaches, the Corals in the neighborhood of coral reefs, and so on. In short, the distribution of animals then as now was in accordance with their nature and habits, and we shall seek vainly for them in the localities where they did not belong. But when I say that the character of the Jurassic animals is the same, I mean, that, wherever a Jurassic sea-shore occurs, be it in France, Germany, England, or elsewhere throughout the world, the Shells, Crustacea, or other animals found upon it have a special character, and are not to be confounded by any one thoroughly acquainted with these fossils with the Shells or Crustacea of any preceding or subsequent time,--that, where a Jurassic marsh exists, the land Reptiles inhabiting it are Jurassic, and neither Triassic nor Cretaceous,--that a Jurassic coral reef is built of Corals belonging as distinctly to the Jurassic creation as the Corals on the Florida reefs belong to the present creation,--that, where some Jurassic bay or inlet is disclosed to us with the Fishes anciently inhabiting it, they are as characteristic of their time as are the Fishes of Massachusetts Bay now.