Florometra with third syzygy usually between brachials 16+17 (sometimes 15+16). Basal pinnulars of oral pinnules markedly carinate and appearing much broader than rest of pinnule especially in lateral view. Longest cirrals with L/W ratio not more than 2. Longest proximal brachials distinctly broader than long.
Clark AH, Clark AM (1967) A monograph of the existing crinoids 1(5). Bulletin of the United States National Museum (82):1-860.