The more yellow among these are definitely money cowries, Monetaria moneta. One website or another might call the more regularly shaped ones with orange rings money cowries, but they're ring-top cowries, Monetaria annulus. It's not clear to me if those were really worth anything more than the $4.95 (plus shipping) it might cost you for a baggie full on the net. Whichever medium of exchange was allowed, money cowries like these were used from Africa eastward across the Pacific. They were traded over an even wider range.