Asteronyx Müller & Troschel, 1842 ( type species: A. loveni Müller & Troschel, 1842).
Astrodia Verrill, 1899b, Astronebris Downey, 1967, Ophioschiza H.L. Clark, 1911.
Dorsal disc with thickened skin, few or no scales, radial shields bar-like, almost meeting in disc centre. Long, tapering arms, covered by thickened skin, lacking dorsal plates. Multiple columns of spiniform teeth, dental plate entire. Arms not branching. All vertebrae without oral bridge. Gonads restricted to disc. Arm spine articulation as slightly tumid regular stereom with large oval or round opening.