It is a type of larva among the Nemertines, which is characterized by being plump and ciliated. It is also known as Larva desor or Larva Pilidium. It means with hairs, with fluff, hairy.
Pilidio : 1 : Genus of spherosidal fungi . . 2 : Genus of gastopod molluscs. -3 : Name given to larval forms of certain worms, such as Nemertines.