""Descriptions Of Species Of Pleistocene Vertebrata, Types Or Specimens Of Most Of Which Are Preserved In The United States National Museum"" is a scientific book written by Oliver Perry Hay and published in 1921. The book provides a comprehensive description of various species of vertebrates that lived during the Pleistocene epoch, which is the geological period that began about 2.6 million years ago and ended approximately 11,700 years ago. The...