Figure 10 A–D.
Cryaster H.L. Clark 1923: 292 (non Cryaster Koehler, 1906)
Tylaster Mortensen 1933: 249 (non Tylaster Danielssen & Koren, 1881)
Spoladaster Fisher 1940: 135; A.M. Clark 1976: 254–258; Hotchkiss & A.M. Clark 1976: 265; A.M. Clark 1984: 41.
Type species: Cryaster brachyactis H.L. Clark 1923, by original designation
Diagnosis. (Following Clark 1984, Clark & Downey 1992). Body swollen and cushion-like, pentagonal in outline (R/r= 1.2–1.6). Larger individuals (R/r=~ 1.5 at R>5.0) with more stellate body shape versus smaller with more pentagonal outlines. Body wall thickened. Short, pointed spinelets embedded in body wall surface. Abactinal plates minimal, reduced into body wall, especially in larger specimens. Papulae covers most of abactinal surface. Marginal plates best observed in smaller specimens (R= 1.5 –2.0) (Fig. 10 C, D), embedded in thickened body tissue, obscured in larger specimens (R>~3.0) (Fig. 10 A, B). Actinal plates imbricate, in transverse series but becoming minimized. If present, concealed by thickened body tissue in larger specimens (R>~3.0) (Fig. 10 A, B). Furrow spines one to three (two to three in most). Subambulacral spines larger.
Included species: S. veneris Perrier 1879