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 flatworms, flat worms, Platyhelminthes, Plathelminthes, or platyhelminths are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates, and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion and egestion; as a result, the food cannot b