Litophyton swainensis sp. nov.

(Figs. 85g, 97d, 103)

Material examined. Holotype NTM C1371, Queensland, Swain reefs, Sweet-lip reef, 15 November 1980, coll. P. Alderslade ; paratypes: NTM C651, March 1978, coll. D. Schubot; NTM C652, March 1978, coll. D. Schubot; NTM C1372, Queensland, Swain reefs, Sanctuary reef, 15 November 1980, coll. P. Alderslade; NTM C 1374-1376, 1378, Queensland, Swain reefs, Sweet-lip reef, 15 November 1980, coll. P. Alderslade.

Description. The holotype is 4 cm high and 4.5 cm wide, the stalk is 1.5 cm long (Fig. 97d). The polyps are up to 0.6 mm wide and high, they are grouped in spherical catkins.

Polyps. With a relatively good arrangement of sclerites in eight points (Fig. 85g). Abaxially and laterally point sclerites are spindles; abaxially up to 0.50 mm long, with simple tubercles and spines (Fig. 103a). Laterally they are up to 0.20 mm long (Fig. 103b). Adaxially there are small, curved scales, up to 0.10 mm long, similar to those of the tentacles (Fig. 103c). The polyp stalk has straight rods, up to 0.10 mm long (Fig. 103d). Supporting bundle not projecting or slightly so, composed of spindles, up to 1.30 mm long, with simple tubercles and one spiny end (Fig. 103e).

Surface layer top stalk. Spindles and unilaterally spinose spindles, all with simple and complex tubercles (Fig. 103 f-g). A few capstans and derivatives of capstans are also present (not depicted), also with simple and complex tubercles. Capstans 0.10-0.15 mm long; spindles up to about 0.35 mm long.

Surface layer base stalk. Capstans, derivatives of capstans, spindles, and unilaterally spinose spindles, all with simple and complex tubercles (Fig. 103 h-i). Capstans 0.05-0.20 mm long; spindles up to about 0.20 mm long.

Interior stalk. Spindles, up to 1.1 mm long (Fig. 103 j-k), with pointed ends and simple tubercles (Fig. 103l). Unfortunately the SEM images showed shorter spindles than the microscope slide.

Etymology. Named after the holotype locality.

Distribution. Great Barrier Reef: Sanctuary reef, Sweet-lip reef.

Remarks. The species resembles L. folium sp. nov. but has finer spines on the surface sclerites and finer tuberculation on the interior stalk sclerites, which are also slightly longer. Moreover, L. folium sp. nov. has many smaller branched interior stalk sclerites (Fig. 87a), whereas they are seldom branched in L. swainensis .