Rocks & Minerals

Texas Rocks and Minerals

The Ultimate Rockhounding Handbook

Snails

Underground Treasures: How and Where to Find Them

Walks and Talks in the Geological Field

A Short History of the Academy of Natural Sciences of Philadelphia

The Ornithosauria

Biology, The Myth Of Evolution

Canyons of the Colorado

Cave Regions of the Ozarks and Black Hills

Underground Treasures: How and Where to Find Them

Fragments of Earth Lore: Sketches & Addresses Geological and Geographical

Lifeful Stories of Lifeless Rocks

Gemstones