Distinguished from Dialithocidaris by having just a single primary tubercle on interambulacral plates, not two, and by lacking rows of glassy pegs.
Agassiz, A. & Clark, H. L. 1907. Preliminary reports on the Echini collected in 1902, among the Hawaiian Islands, by the U. S. Fish Commission steamer “Albatross”, in charge of Commander Chauncey Thomas, U. S. N. commanding. Bulletin of the Museum of Comparative Zoology, Harvard College, 50, 231-259.
Agassiz, A. & Clark, H. L. 1908. Hawaiian and other Pacific Echinidi. Memoirs Harvard Museum of Comparative Zoology 34, 43-134, pls 45-59.
Mortensen, T. 1935. A monograph of the Echinoidea II. Bothriocidaroida, Melonechinoida, Lepidocentroida and Stirodonta. C. A. Reitzel, Copenhagen.