Ophiosphalma diomedeae (Lütkeni & Mortensen, 1899) .

Figures 47 a, b

Ophiomusium diomedeae Lütkeni & Mortensen, 1899

Syntypes (2), USNM 19501, Albatross 1891, E San Cristobal Id, Galapagos 702 m.

Main Features: Disc flat with well-defined scales, many in centre. Radial shields less than half disc radius, finely rugose and non-imbricating. Arm plates throughout, 6 small thick arm spines. 3 large exposed tentacle pores and 1 occasionally 2 tentacle scales. Genital slits run to the edge of the disc. Genital papillae strong abradially only. Oral shield small, oral plate large. One juvenile specimen, 5 mm d.d. has the radial shields joined for the first third, and all the disc plates have 3–4 small tubercles.