Family Ophiacanthidae Ljungman, 1867 Synonyms Ophiochondrinae Verrill, 1885: 355. Ophioplinthacinae Paterson, 1985: 61. Ophiocanopidae Mortensen, 1932: 8. Type genus Ophiacantha Müller & Troschel, 1842 (type species: O. bidentata (Bruzelius, 1805)). Other genera Ophialcaea Verrill, 1899a, Ophientrema Verrill, 1899b, Ophiocanops Koehler, 1922a, Ophiochondrus Lyman, 1869, Ophiohamus O’Hara & Stöhr, 2006, Ophiolebes Lyman, 1878a, Ophiolimna Verrill, 1899a, Ophiomitrella Verrill, 1899a, Ophiomoeris Koehler, 1904, ‘ Ophiophthalmus’ Matsumoto, 1917, Ophioplinthaca Verrill, 1899b, Ophioripa Koehler, 1922a, Ophiosemnotes Matsumoto, 1917, Ophiurothamnus Matsumoto, 1917. Diagnosis Dorsal disc fully scaled, with thorny spines or granules, or with thickened skin. No tooth clusters. Dental plate entire with single column of wide sockets with low dorsal and ventral border, not penetrating. Arm spine articulations bordered by raised, dorsoventrally striated ridge. Ventral portion of lateral arm plates (the portion below the row of spine articulations) small and not protruding ventro-proximalwards. Ridge on inner side of lateral arm plates with two kinks and a dorsal tip with a ventro-proximalwards pointing projection. Remarks The genera Ophiacantha, Ophiomitrella and Ophiolebes are polyphyletic and require revision.

Published as part of Stöhr, Sabine, Hugall, Andrew F., Thuy, Ben & Martynov, Alexander, 2018, Morphological diagnoses of higher taxa in Ophiuroidea (Echinodermata) in support of a new classification, pp. 1-35 in European Journal of Taxonomy 416 on page 14, DOI: 10.5852/ejt.2018.416, http://zenodo.org/record/3806109