UNITED STATES, CANADA AND MEXICO 257
shells
of some varieties, such as the common clam and the conch, were made
into wampum; and that the pearls found in the shells were used as
ornaments, whether lusterless pearls from the common oyster or lustrous
ones from the Unio. The great shell-heaps along our coasts bear
evidence that many pearls must have been found, and that, though the
Spaniards who invaded the country may indeed have obtained great hoards
of pearls, all of them, perhaps, were not of great value.