The lorica of these organisms is made up of dorsal and ventral plates that are not joined at the edges, giving them a thin and underdeveloped appearance. Their bodies have a prismatic or spindle-like shape, and their two toes are typically slender and curved. The foot is rudimentary and lacks joints. The mastax is virgate and features both rami and unci with very simple structures. Unlike some other species, they lack a retrocerebral sac.