Shell money most valued by the Native American tribes of the Pacific Coast from Alaska to northwest California was "Dentalium shell", a species of long narrow marine shelled mollusk, a tusk shell or scaphopod. The tusk shell is naturally open at both ends, and can easily be strung on a thread. This shell money was valued by its length rather than the exact number of shells; the "ligua", the highest denomination in their currency, was a length of about 6 inches. Farther south, in central California and southern California, the shell of the olive snail "Olivella biplicata" was used to make beads
Puka shell the "puka" or central hole is perfectly circular and parallel-sided, then the hole was drilled by humans. Puka shell Puka shells originally were naturally occurring bead-like objects which can be found on some beaches in Hawaii. Each one was the beach-worn apex of a cone snail shell, a kind of seashell from a sea snail. "Puka" is the Hawaiian word for "hole" and refers to the naturally occurring hole in the middle of these rounded and worn shell fragments. These natural beads were made into necklaces. Numerous inexpensive imitations are now widely sold as puka shell necklaces. The majority of