Class

• Oligochaeta

  Earthworms.

• Polychaeta

  Marine annelid worms.

• Hirudinea

  Hermaphroditic aquatic or terrestrial or parasitic annelids.

• Archiannelida

  A class of Annelida.

Also contains

• annelid

  Worms with cylindrical bodies segmented both internally and externally.