Ophiosphalma corticosum (Lyman, 1878)

Figures 46 a, b

Ophiomusium corticosum Lyman, 1878; Gouzhen, 1987.

Syntype BMNH 82-12-23 -423, Challenger station 22, Caroline Islands, East Indies, 3383m. There is a syntype of this species in the MCZ (442)—3 were collected by HMS Challenger, so one is missing. The comments here are based on both types and the illustrations are of MCZ 442.

Main Features: The disc is tumid and the radial shields are curved downwards distally. The disc plates are finely granular and there are deep smooth sutures between the plates. 8 small arm spines. Heavy oral papillae, some separated. Large tentacle scales, 3–4 exposed tentacle pores, protuberant ventral arm plates. Small drop-shaped oral shields, genital slits 2.5 arm segments long with papillae on one side only.