Evolution of mammalian molar teeth to and from the triangular type, including collected and revised researches on trituberculy and new sections on the forms and homologies of the molar teeth in the different orders of mammals. By Henry Fairfield Osborn, Sc.D., LL.D., D.Sc., edited by W. K. Gregory, M.A. New York: The Macmillan Company, 1907. pp. i-ix + 1-250, including bibliography, with 215 figures in the text