Ophiomusium lymani Wyville-Thomson, 1873 .

Figures 21 a, b

Ophiomusium lymani Wyville-Thomson, 1873; Martynov & Litvinova, 2008. Ophiomusa lymani Hertz, 1927, H. L. Clark, 1939.

Ophiomisidium lymani (A. M. Clark & Courtman-Stock), 1976 .

Lectotype BMNH 90.2. 19.9.10, Porcupine Expedition off the west coast of Ireland. Surprisingly for such a wellknown and widely distributed species, a holotype is not identified in the BMNH collections. One specimen BMNH 90.2. 19.9.10, 28 mm d.d. longest arm 78 mm, from the Porcupine sample, is here selected the lectotype. A second specimen in the same lot has all its arms broken, but is here selected as a paralectotype. There are many other specimens in the BMNH collected from all oceans depths between 1033 and 3338 m. 4 specimens from the Western Australian Bight, 1080–1100 m were examined in the AM (J10018).

Main Features: Disc plates covered with fine skin, granular. Small primaries with central prominence. Radial shields long and pear-shaped, separated by 4–5 plates. Multiple interradial plates extending to ventral surface of disc. Oral shields pear-shaped, with a 5-sided plate of similar size attached distally. The lectotype has 2 pairs of exposed tentacle pores on the only two ventral arm plates. One tentacle pore scale. 6 to 8 short arm spines adpressed to arm (note: some specimens have up to 13 arm spines). Lateral arm plates surround arm.