polygordius

from The Century Dictionary.

• noun The typical genus of the family Polygordiidæ, referred to the annelids as type of a group, Archiannelida. P. purpureus and P. luteus are two species, the former hermaphroditic, the latter diœcious.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Zoöl.) A genus of marine annelids, believed to be an ancient or ancestral type. It is remarkable for its simplicity of structure and want of parapodia. It is the type of the order Archiannelida, or Gymnotoma. See loeven's larva.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun zoology A genus of marine annelids, believed to be an ancient or ancestral type. It is remarkable for its simplicity of structure and want of parapodia. It is the type of the order Archiannelida, or Gymnotoma.