Fig. 4

SEM images of extant species of Ophiura from the North Sea and North Atlantic; O. sarsii Lütken, 1855, off Iceland, genital plates and scales as typical of the genus Ophiura (a); O. albida Forbes, 1839, Kattegat, 4 mm dd, with coarse disc scalation (b), at 8 mm dd, dorsal view (c), dorsal arm plates (d), lateral arm plates with spines (e), ventral view, slightly overbleached (f); O. sarsii, dorsal disc, 6 mm dd (g), ventral disc, 7 mm dd (h). Specimens have all been bleached with household NaOCl to remove the integument, dd disc diameter, other abbreviations as in Fig. 3. Scale bars in millimetres