The Origin and Evolution of Life

Men of the old Stone Age

Evolution of mammalian molar teeth

Biographical Memoir of Joseph Leidy, 1823-1891

From the Greeks to Darwin

The Four Phyla Of Oligocene Titanotheres

Proboscidea, Vol. 2: A Monograph of the Discovery, Evolution, Migration and Extinction of the Mastodonts and Elephants of the World; Stegodontoidea, Elephantoidea (Classic Reprint)

Collected Papers, Volume 1

Oxyaena and Patriofelis Re-Studied As Terrestrial Creodonts

Men of the Old Stone Age - Their Environment, Life and Art

The Titanotheres of Ancient Wyoming, Dakota, and Nebraska, Vol. 1 (Classic Reprint)