Ophiura is different from Balanoglossus in having

The most distinctive feature of echinoderms (Ophiura) is the presence of water vascular system which helps in locomotion, capture and transport of food and respiration.Both echinoderms and hemichordates are coelomates. Notochord is absent in both.Proboscis gland is the excretory structure of Balanoglossus. Ophiura does not have any.