Haeckel's presentations are from a different point of view. His "History of Creation" of 1870 presents the ages as "Strata of the Earth's Crust," in which he prefers "upper", "mid-" and "lower" based on the order in which one encounters the layers. His analysis features an Upper and Lower Pliocene as well as an Upper and Lower Diluvial (his term for the Pleistocene). Haeckel, however, was relying heavily on Lyell. In the 1833 edition of "Principles of Geology" (the first) Lyell devised the terms Eocene, Miocene and Pliocene to mean periods of which the "strata" contained some (Eo-, "early"), lesser (Mio-) and greater (Plio-) numbers of "living Mollusca represented among fossil assemblages of western Europe." The Eocene was given Lower, Middle, Upper; the Miocene a Lower and Upper; and the Pliocene an Older and Newer, which scheme would indicate an equivalence between Lower and Older, and Upper and Newer.