Que tem conchas com as valvas em forma de tubo.
(De fistula + valva)
fis-tu-li-val-ve
conivalve, polivalve, homovalve, eqüivalve, quadrivalve, salve, octovalve, equivalve, evalve, plurivalve, multivalve, trivalve, qüinqüevalve, ineqüivalve, univalve