Elasipodida

Théel, 1879

5 Families; 24 genera, 11 monotypic; 141 species

Tube feet present; tentacles shield-shaped (Pelagothuridae more dendritic); retractor muscles and respiratory trees absent. Mesentery of posterior loop of intestine attached in the right dorsal interradius, usually near the right dorsal longitudinal muscle. Among the calcareous bodies are pointed rods and such as are derived from pointed rods, Shape of the body usually bilateral. (Mortensen, 1925)

(Hansen thoroughly revised this order, with the exception of the family Pelagothuriidae). Mesentery with dorsal attachment throughout its length. Respiratory trees absent. (Hansen, 1975)