Unionoida
... that Unionoida freshwater mussel shells were used to make buttons?
... that <b id="mwCcY"><a class="mw-redirect" href="./Unionoida" id="mwCcc" rel="mw:WikiLink" title="Unionoida">Unionoida</a></b> freshwater mussel shells <i id="mwCcg">(pictured)</i> were used to make <a class="mw-redirect" href="./Buttons" id="mwCck" rel="mw:WikiLink" title="Buttons">buttons</a>?