(class Stelleroidea, subclass Ophiuroidea)
An order of primitive brittle-stars in which dorsal and ventral arm-plates are lacking, as are large plates of the disc (radial shields, etc.). The body cavity, containing gonads and digestive organs, extends into the base of the arms. The order is, though mainly Palaeozoic, Ordovician to Holocene with one extant genus, Ophiocanops.
Subjects: Zoology and Animal Sciences.