Catalogue of Batrachians and Reptiles of Central America and Mexico

The Origin of the Fittest: Essays on Evolution

Report on the Vertebrate Paleontology of Colorado

Check-list of North American Batrachia and Reptilia: With a Systematic List of the Higher Groups, and an Essay on Geographical Distribution ; Based on the Specimens Contained in the U. S. National Museum, Volume 13

Recent Papers Relating to Vertebrate Paleontology

On the Extinct Cats of America

Researches Upon the Antiquity of Man in the Delaware Valley and the Eastern United States

Classification of the Collection to Illustrate the Animal Resources of the United States: A List of Substances Derived from the Animal Kingdom, with Synopsis of the Useful and Injurious Animals and a Classification of the Methods of Capture and Utilization