Ophiosphalma glabrum (Lütken & Mortensen, 1899), Lutken & Mortensen, 1899

Baker, Alan N., 2016, An illustrated catalogue of type specimens of the bathyal brittlestar genera Ophiomusium Lyman and Ophiosphalma H. L. Clark (Echinodermata: Ophiuroidea), Zootaxa 4097 (1), pp. 1-40 : 31

Ophiosphalma glabrum (Lütken & Mortensen, 1899) .

Figures 51 a, b, c, d

Ophiomusium glabrum Lütken & Mortensen, 1899 ; H. L. Clark, 1917 Ophiomusium fimbriatum Koehler, 1922 Ophiomusium multispinum H. L. Clark, 1911 (synonymised with O. glabrum by H. L. Clark, 1913).

Syntypes of O. glabrum : BMNH 1901.4.9.43/7, Albatross station 3376, Gulf of Panama, 1132 fms; syntypes (56), USNM E19494 , 19496, 19498, 19499, 19500, Albatross stations 3381, 3392, 3400, 3414, 3431, Off Columbia, Bay of Panama and Mexico, 1820–4082m. Dr Marc Eleaume, Paris Museum, has recently informed me that a syntype of O. glabrum is in their collection: NMNH 10254, as is a possible type specimen of O. fimbriatum : NMNH10389, ex- Albatross Expedition.

Holotype of O. fimbriatum : USNM E188 Albatross station 5614, Mollucca Passage, 2011 m.

Main Features: Disc finely granular, very many small non-imbricating plates in centre and gradually enlarging towards margins. Radial shields large, comma-shaped, separated by reticulate rows of scales, 4–5 wide. Ladder-like arrangement of wide/narrow plates between distal ends of radial shields. A group of small pointed stumps each side of arm on disc edge visible dorsally and ventrally. Dorsal arm plates throughout arm. Up to 12 small arm spines, the longest lowest. Three pairs of exposed tentacle pores. 4 scales on first pore. Ventral arm plates throughout, genital slits run to end of first lateral arm plate. Oral shield triangular with slight concave distal margin. Seven oral papillae, not separated. Many hexagonal non- imbricating scales in post-oral shield area.

O. fimbriatum Koehler is a synonym of O. glabrum . It has short genital slits, the oral shield is arrow-headed, and it has 3–5 exposed tentacle pores, all of which may be regarded as age- related.