Sphaeriodiscus Fisher, 1910

Sphaeriodiscus Fisher, 1910: 171; 1911: 167; Tortonese & A.M. Clark, 1956: 343; Halpern, 1970 b: 79; A.M. Clark & Courtman-Stock, 1976: 249; Downey in Clark & Downey, 1992: 265; H.E.S. Clark & McKnight, 2001: 133.

Diagnosis. Body pentagonal. Abactinal plates weakly tabulate, covered by evenly distributed granules. Marginal plates few, tumid with swollen or enlarged penultimates. Pedicellariae spatulate.