Digestive system: Careoradula perelegans is unique among other streptaxids, because it has no radula, no odontophore and no retractor muscles associated with these structures.
has raised the tribe Eocypraeini to the status of the family Eocypraeidae, based on morphological research of the radulae, shell and animal morphology and molecular phylogeny research of the 16S ribosomal RNA gene.
Eurybia radula is present in every province of Canada east of and including Ontario and is also present on the French territory of St. Pierre and Miquelon.