“STYRACASTER, n. gen.
Rays five, long and attenuate, incapable of being reverted. Superomarginal plates meet in the median dorsal line, encasing the ray, and bear long, robust, cylindro-conical spines which form a single series along the median dorsal line. Abactinal area covered with membrane, beset with simple spiniferous spicules or with pseudo-paxillm. No specially developed epiproctal protuberance. Actinal interradial area paved with thin, smooth plates, arranged in regular columns, more or less clearly imbricating, and covered with a delicate membrane. Ambulacral furrows narrow and more or less enclosed. Ambulacral spines elongate, needle-shaped, and with a tendency to radiate apart. Cribriform organs three to seven in number in each angle.”
(Sladen, 1883: 229)
