Litophyton myrmidonensis sp. nov.

(Figs. 12b, 13c, 16-17)

Material examined. Holotype NTM C994, 1978, coll. D. Schubot; paratypes: NTM C3951, Queensland, Great Barrier Reef, Myrmidon reef, depth 1-5 m, 7 January 1981, coll. Z. Dinesen; NTM C4393, Queensland, Great Barrier Reef, Myrmidon reef, depth 10-15 m, 3 February 1981, coll. Z. Dinesen; other material: NTM C2247, Queensland, Briggs-Sudbury reef, March 1978, coll. P. Alderslade.

Description. The holotype NTM C994 is 16 cm high and 15.5 cm wide, the stalk is 4 cm high (Fig. 12b). The base of the stalk has a flap of tissue, probably encrusting the substrate when the colony was alive. The polyps are up to 0.8 mm wide and 0.45 mm high, grouped in oblong to spherical catkins.

Polyps. With irregular arrangement of sclerites in eight points (Fig. 13c). Abaxial and lateral point sclerites are spindles with simple tubercles and spiny distal part, largest present abaxially, up to 0.40 mm long, towards the adaxial points they become smaller (Fig. 16a). Tentacles with curved scales up to 0.10 mm long (Fig. 16b). Adaxial side of the polyp stalk with straight rods up to 0.20 mm long (Fig. 16 c-d). A couple of these rods have a rough surface texture. Supporting bundle composed of one or two spindles up to 2 mm long, with simple tubercles, and a smooth or spiny tip projecting for a maximum distance of 0.40 mm (Fig. 16e).

Surface layer top stalk. Spindles and unilaterally spinose spindles, up to 0.80 mm long, with simple and complex tubercles (Fig. 16 f-g). The unilaterally spinose sclerites have long spines.

Surface layer base stalk. Capstans, derivatives of capstans, spindles, and unilaterally spinose spindles, with simple and complex tubercles (Figs. 16 h-i, 17a-b). The spindles are up to 0.80 mm long. The unilaterally spinose sclerites have long spines. In the flap unilaterally spinose sclerites are lacking (Fig. 17 c-d).

Interior stalk. Spindles with pointed ends, up to 2.00 mm long (Fig. 17 e-f), with simple and complex tubercles (Fig. 17g).

Etymology. Named after the paratype locality.

Distribution. Great Barrier Reef: Myrmidon reef, Briggs-Sudbury reef.

Remarks. This is the only Litophyton species with projecting supporting bundle with spindles with a smooth tip and polyp stalks with long rods.

With some doubts NTM C2247 is included in this species as it shows some supporting bundle spindles with smooth, projecting tip and long rods in the polyp stalk, but its interior stalk spindles differ, being only 0.85 mm long.

The unilaterally spinose sclerites with very long spines are very distinctive but are in group I also present in L. dipensis sp. nov., L. elfordensis sp. nov., and L. graafae sp. nov. The differences between these species are discussed with L. dipensis .