Antedon with arms up to 70 mm long. Centrodorsal flattened hemispherical. Cirri in largest specimens about one-eighth arm length, in smaller ones up to a quarter arm length. Cirri 20-55 with arms >20 mm, 13-16 cirrals; longest cirrals with L/W ratio ~2; antepenultimate L/W ratio ~1.5. P1 of 12-28 segments; P2 about half as long as P1 or shorter; P3 slightly larger than P2 with gonad. Brachials and pinnulars may be prominently spinous.
Clark AH, Clark AM (1967) A monograph of the existing crinoids 1(5). Bulletin of the United States National Museum (82):1-860.