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
Wampum contact, strings of wampum were used for storytelling, ceremonial gifts, and recording important treaties and historical events, such as the Two Row Wampum Treaty or The Hiawatha Belt. The term "wampum" (or "wampumpeag") initially referred only to the white beads which are made of the inner spiral or columella of the Channeled whelk shell "Busycotypus canaliculatus" or "Busycotypus carica". "Sewant" or "suckauhock" beads are the black or purple shell beads made from the quahog or poquahock clamshell "Mercenaria mercenaria". "Sewant" or "Zeewant" was the term used for this currency by the New Netherland colonists. Common terms for the dark and