"The authors remarked that the people of the Congo valued the shells though they were of no use to them but only to trade with other Africans "who adore the sea and call these shells, which their country does not afford, 'God's children', for which reason they look upon them as treasure and take them in exchange for any sort of goods they have. Among them he is the richest and happiest who has most of them. (Angelo and Carli p.158)"
Paul Einzig Primitive Money (1948) p.167