I thought I'd better sort this out, as the name "dentalium" rang a bell, from Ed's post, and I'd been expecting Ray to correct or elaborate my comments, and his description of purple shells obviously didn't jibe with the west coast tubes. so, a quick web search on +dentalium +wampum turned up a bunch of hits, probably the most detailed being
freepages.genealogy.rootsweb.com/~jcahill/wampum.htm which reveals that the white dentalium tube shells from Vancouver Island were called "wampum" by european explorers in analogy to the wampum from the Algonquin Indians who made the beads from the very hard purple parts of an east coast clam shell, carving them as narrow cylinders with a hole down the long axis, an impressive feat prior to recourse to steel drills. Interesting to note that as the dentalium travelled as far as lake superior, european explorers would have seen concrete evidence of the pacific ocean very early on in their explorations, but wouldn't have realized the significance. -PV
