Taxonomic analysis of the genital plates and associated structures in Ophiuroidea (Echinodermata) Author Stöhr, Sabine text European Journal of Taxonomy 2024 2024-05-14 933 1 98 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2525/11335 journal article 10.5852/ejt.2024.933.2525 2118-9773 11198874 8F720F2B-BFBC-4CA1-BFF2-A2B8C7C8D3E1 Genus Ophiochiton Lyman, 1878 Fig. 24A–C Type species Ophiochiton fastigatus Lyman, 1878 . Examined species Ophiochiton fastigatus . Oral GP Externally visible as large, round scales, but not examined. Adradial GP Weakly cleaver-shaped, flat, blade-like proximal part, distal end depressed with high edges, a large rough patch on adradial surface towards dorsal edge, and a large hole in middle of distal part on adradial surface. Abradial GP Hockey-stick-shaped, blade-like, flat, as long as adGP, distal end angled, pointed, distal dorso-adradial edge with depression. Lines abradial edge of genital slit (= part of edge of interradial disc). Oral shields Not examined. Radial shield Not examined. Remarks The available pre-existing images allow only limited assessment of the articular structures of the adradial GP. Martynov (2010) described them as a condyle bordered by a low ridge but without figures, whereas Matsumoto (1917) wrote that the radial shield and adradial GP articulate with two condyles and one pit. The images presented here appear to be the first published SEM images of genital plates of Ophiochiton .