Chloe Kim #1 of the United States competes in the FIS World Cup 2018 Ladies Snowboard Halfpipe final during the Toyota U.S. Grand Prix on December 9, 2017 in Copper Mountain, Colorado. Matthew StockmanâGetty Images.
The phylum name Platyhelminthes literally means flatworms.. Members of this phylum are soft, thin-bodied, leaf or ribbonlike worms, including the familiar planaria of ponds and streams, as well as the flukes and tapeworms parasitic in human and other animal bodies.
The phylum Platyhelminthes contains about 13,000 species of flatworms subdivided into three classes: two parasitic and one free-living. The planaria and relatives are freshwater animals placed in the class Turbellaria. Flukes are external or internal parasites belonging to the the Class Trematoda.