- On the Batrachia and Reptilia of Costa Rica with Notes on the Herpetology and Ichthyology of Nicaragua and Peru
- On the Structures and Distribution of the Genera of the Arciferous Anura
- The Batrachia and Reptilia of Costa Rica: Atlas
- Synopsis Of The Extinct Batrachia And Reptilia Of North America
- Origin of the Fittest: Essays on Evolution and the Primary Factors of Organic Evolution (Natural Sciences in America)