Fig. 11

Ossicles of extant tremasterines, korethrasterids and pterasterids. a–e, l, p, q, r Tremaster mirabilis Verrill, 1879. a, b Oral ossicle, radial a and interradial b views. c Ambulacral. d, e Odontophore. l adambulacral, actinal view. p, q Circumoral ossicle. f, h, i, k, s Peribolaster lictor Fell, 1958. f Odontophore. h, i Oral ossicle. k, s Adambulacral ossicle. g Pteraster pulvillus Sladen, 1889. Odontophore. m, n, u, v Pteraster coynetes Fisher, 1916. m, n Oral ossicle. u, v Circumoral. j, t Pteraster tesselatus Ives, 1888. Tremaster mirabilis, Victoria Museum, f 1,101,124. Macquaqrie Island, Tasmania. Peribolaster lictor Fell, 1958. NIWA 23,057, New Zealand, 43.9000S, 179.2333W, Pteraster corynetes, Phillippines, purchase. Pteraster tesselatus, Washington State, USA. Note the similarity in adamb construction between Tremaster mirabilis r, Peribolaster lictor s and Pteraster t. The abrupt abradial margin in T. mirabilis marks the contact with the actinal ossicles. In velatids (P. lictor and Pteraster) an ambulacral extension is present, which extends to the ambitus. Scale bars equal 5 mm (a, b, d, e, p, q)1 mm (f–i, l, r) and 0.5 mm (j, k, m, n, o, s–v)