There is a strange little symbol hiding on every dollar bill, and no one can agree on what it is. Some say it's a spider. Others insist it's an owl.

It’s one of the most frequent dollar bill symbols. There are 13 arrows, 13 olive branch leaves, 13 olive fruits, 13 stars above the eagle, 13 steps of the pyramid, and 13 bars on the shield.

The Secret Symbols of the Dollar Bill: A Closer Look at the Hidden Magic and Meaning of the Money You Use Every Day David Ovason. HarperCollins Publishers, $18.95 (192pp) ISBN 978-0-06-053044-0 ...