Rocks & Minerals

British Museum (Natural History) General Guide

Gems in the Smithsonian Institution

Underground Treasures: How and Where to Find Them

The Geology of Groton State Forest

Walks and Talks in the Geological Field

A Short History of the Academy of Natural Sciences of Philadelphia

Devils Tower National Monument

The Ornithosauria

Biology, The Myth Of Evolution

The Glaciers of the Alps

Cave Regions of the Ozarks and Black Hills

Pleistocene Bats from San Josecito Cave, Nuevo Leon, Mexico

Pleistocene Bats from San Josecito Cave, Nuevo Leon, Mexico

Underground Treasures: How and Where to Find Them

Fragments of Earth Lore: Sketches & Addresses Geological and Geographical

Mount Rainier, a Record of Exploration

Florida Caverns State Park

Beach Rambles in Search of Seaside Pebbles and Crystals

Canyons of the Colorado

Across Mongolian Plains