errantia

from The Collaborative International Dictionary of English v.0.48

Errantia \Er*ran"ti*a\, n. pl. [NL., fr. L. errare to wander.
   See {Err}.] (Zo["o]l.)
   A group of ch[ae]topod annelids, including those that are not
   confined to tubes. See {Ch[ae]topoda}. [Written also
   {Errantes}.]
   [1913 Webster]