The orders Atremata and Neotremata are frequently grouped together, as the sub-class Inarticulata or Ecardines - the Tretenterata of Davidson - and the orders Protremata and Telotremata, as the Articulata or Testicardines - i the Clistenterata of Davidson.
We have, in fact, returned very nearly to Cuvier's conception of a great division or branch, which he called Articulata, including the Arthropoda and the Chaetopoda (Annelides of Lamarck, a name adopted by Cuvier), and differing from it only by the inclusion of the Rotif era.