and published La Paléontologie Française (8 vols). In 1849 he published a closely related Prodrome de Paléontologie Stratigraphique, intended as a "Preface to Stratigraphic Palaeontology", in which he described almost 18,000 species, and with biostratigraphical comparisons erected geological stages, the definitions of which rest on their stratotypes.

In 1853 he became professor of palaeontology at the Paris Muséum National d'Histoire Naturelle,