Aspidosiphonidae
Aspidosiphonidae is a family of peanut worms. It is the only family in the monotypic order Aspidosiphonida, which is in the class Phascolosomatidea. Description. The family Aspidosiphonidae is characterized by an oral disk with short tentacles arranged in a crescent enclosing nuchal organ. Present a coelomisd canal of sacs not present in body wall the longitudinal muscles layer either continuous or in band. Present anterior and terminal trunk chitinized to form anal shield, the posterior end usually likewise modified to form caudal shield. Have two nephridia.