Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758 Phylum Nemertea Schultze, 1851 - ribbon worms Neonemertea Thollesson & Norenburg, 2003 Pilidiophora Thollesson & Norenburg, 2003 Heteronemertea see Order Heteronemertea Family Riseriellidae Genus Riserius Norenburg, 1993 1 Riserius pugetensis Norenburg, 1993