Gephyrocrinus Koehler & Bather, 1902

Roux, Michel & Bohn, Jens Michael, 2010, Revision of the genus Gephyrocrinus Koehler & Bather, 1902 (Echinodermata, Crinoidea, Hyocrinidae), Zoosystema 32 (3), pp. 425-437 : 429

Genus Gephyrocrinus Koehler & Bather, 1902

SPECIES INCLUDED. — Monospecific: Gephyrocrinus grimaldii Koehler & Bather, 1902 .

AMENDED DIAGNOSIS. — Five arms, rarely divided at IBr2ax; proximal arm pattern usually 1+2 3 4 5+6 7+8 with first pinnule on Br4, rarely on Br5. Proximal part of genital pinnules with numerous additional plates never in rows; distally with lateral plates on each side all along the pinnule. Tegmen inflated with subconical anal sac well developed on external side and taller than oral cone. Aboral border of basal ring flanged except in some larger specimens. Stalk with symplexies of 6-8 crenular units.

REMARK

As discussed below, the middle and distal arm pattern usually with successive brachial pairs is interpreted as a specific adaptive character which is incorporated into the diagnosis of G. grimaldii .