Ophiosphalma impotens (Koehler, 1922) .

Figures 52 a, b

Ophiomusium impotens Koehler, 1922

Holotype: USNM 40920, Albatross station 5605, Gulf of Tomini, Celebes, 1183m.

Main Features: The holotype is deformed, with a large plate protruding out from one interradial area. The disc has many moderately large imbricating plates, and small, well separated radial shields (less than ½ disc radius). There are small dorsal and ventral arm plates throughout and 6 short arm spines. The genital slits extend to 1 ½ lateral arm plates. There are three exposed tentacle pores, each with one large scale. The oral shield is tear-drop shaped, sharp proximally. There are 6 non-separated oral papillae each side of the jaw, plus one terminal tooth.