Endoxocrinus (Diplocrinus) alternicirrus sibogae (Döderlein, 1907)

Figures 13 c–d.

Synonym: Isocrinus sibogae Döderlein, 1907: 18; Endoxocrinus sibogae A. H. Clark, 1908b: 152; Cenocrinus (Diplocrinus) sibogae Döderlein, 1912: 20 –21; Diplocrinus sibogae A.H. Clark, 1923: 11; Diplocrinus aff. sibogae Bourseau et Roux, 1987: 158; Diplocrinus (Diplocrinus) sibogae Bourseau et al., 1991: 259; Endoxocrinus (Diplocrinus) alternicirrus var. sibogae David, 1998: 203 (unpublished data); Endoxocrinus (Diplocrinus) sibogae Roux et al., 2002: 820 .

Emended diagnosis

A robust subspecies of E. (D.) alternicirrus with 26–64 arms (mode 40) up to 14.5 cm long (mean 12 cm); arm branching usually isotomous, proximal brachitaxes not contiguous and constricted at articulation 1+2; number of internodals per mature noditaxis 4–8 (mode 6); stalk length relatively short, up to 9.5 cm (mean 7.0 cm); proximalmost diameter usually up to 8.0 mm, greater in the shallowest specimens (mean 6.5 mm); nodals bearing 4–5 cirri, usually 5; length of cirrals 1.2–1.7 mm (mean 1.5 mm).

Type Locality

Off Timor at a depth of 520 m.

Holotype: Catalogue no. 2066, Zoölogisch Museum, Amsterdam; first figured by Döderlein 1907, Pl. 9, Fig. 1 and Pl. 12, Fig. 12.

Occurrence

Southwestern Pacific from eastern Tasmania and Tonga to the northern Philippines and Timor, at depths from 364 m to 800 m, rarely 970 m (David 1998).