Fossils

Links With the Past in the Plant World

Last Leaves from Dunk Island

The Coal Measures Amphibia of North America

The Frozen North

The Coal Measures Amphibia of North America

Life's Dawn on Earth

Fossils: A Story of the Rocks and Their Record of Prehistoric Life Denver Museum of Natural History, Popular Series No. 3

Fossil Butterflies

Polar Exploration

A Short History of the Academy of Natural Sciences of Philadelphia

The Black Moose in Pennsylvania

Evolution

Dinosaurs, with Special Reference to the American Museum Collections

Animals of the Past

Geological Contemporaneity and Persistent Types of Life

The Radio Boys with the Forest Rangers; Or, The great fire on Spruce Mountain

The Romance of Modern Geology

Primitive Man

The Adventures of a Grain of Dust

The Romance of Natural History, Second Series