Description of two species of the genus Astrodia Verrill, 1899 (Ophiuroidea, Euryalida, Asteronychidae), including a new species from seamounts in the West Pacific

Lateral arm plates and arm spines of Astrodia duospina sp. nov. (holotype: RSIO61068) A, B lateral arm plates from proximal arm, outer view (A), inner view (B) C, D lateral arm plates from distal arm, outer view (C), inner view (D) E, F arm spines from proximal (E) and distal arm (F). Abbreviations: MO muscle opening; NO nerve opening; R ridge. Scale bars: 200 μm (E); 100 μm (F); 90 μm (A, B); 60 μm (C, D).