<marine biology> One of a family of fresh water pectinibranchiate mollusks, having a turret-shaped shell. ... (19 Mar 1998) ... Found on http://www.encyclo.co.uk/local/20973
Me·la'ni·an noun (Zoology) One of a family of fresh-water pectinibranchiate mollusks, having a turret-shaped shell. Found on http://www.encyclo.co.uk/webster/M/43