United States Mint, San Francisco. Obverse: Bust of Liberty as goddess Athena facing left. She wears a crested helmet and carries a shield with the date 1915 in Roman numerals. Reverse: Owl seated on pine bough (the owl was the bird associated with Athena). On the octagonal version, there are eight small dolphins at the eight points of the octagon.
Designed by Robert Aitken, the round and octagonal coins were part of an elaborate attempt to raise money for the Panama-Pacific Exposition. That celebration was held in San Francisco between February and December, 1915. In turn, the exposition was intended to commemorate the completion and opening of the Panama Canal in the previous year. Dolphins were friendly companions of the vessels making the trip from one ocean to another, via the new Isthmian waterway.