Abstract
The total number of described and known, yet undescribed marine platyhelminth species, in the Aotearoa New Zealand region is 414 (Table 8.1, Fig. 8.1). Of this total, 112 (27%) belong to the class Cestoda, 188 (45%) belong to the class Trematoda, 57 (14%) to the class Monogenea, and 57 (14%) are free-living flatworms. Since the previous review by Johns et al. (2009), seven new species and one new genus have been described, 33 species have been recorded from the New Zealand marine realm that were previously known elsewhere, and there are many records of taxa which remain unnamed or unidentified. There has been a considerable increase in known, yet undescribed species, due to more extensive use of molecular methods. A checklist of New Zealand extant Platyhelminthes is provided.