Psolidium granuliferum H. L. Clark

Table 1, Figures 1a, 2b, 4c, 6a

Psolidium granuliferum H. L. Clark, 1938: 503 –04, fig. 49.—H. L. Clark, 1946: 415.— Rowe, 1982: 458, 464, pl. 31.4.—Rowe (in Rowe and Gates), 1995: 318.

Material examined. Holotype: Western Australia, Koombana Bay, Bunbury, 9–15 m, C-A-H Expedition, 26 Oct 1929, MCZ 1666.

Other material. Cape Nauraliste, Geographe Bay, Map Reef, near Two Rocks, limestone reef, coralline foliose algae, 31°28.365'S 115°33.634'E, 7.6 m, A. Sampey, 18 Jul 2005, WAM Z31164 (1); South Australia, W Eyre Peninsula, Smokey Bay, 37 m, N. Pearsons, 1971, SAM K2176 (2); Tasmania, Port Davey, Bramble Cove, NW end, under rock, 4–6 m, K. L. Gowlett-Holmes, 17 Mar 2003, SAM K2174 (2; live colour photo SAM PK 0259).

Description. Psolidium species up to 21 mm long (preserved); body height low to moderately high, dorsal and lateral scales thick, up to 3 mm wide, lumps on surface creating coarsely granuliform appearance; abundant small scales at base of larger scales; tube feet dorsally and laterally inconspicuous, sparse across mid body, usually present near base of scales.

Sole: peripheral band of tube feet, outer single series of distinctly separate smaller tube feet; series of inner larger tube feet 2 wide, series not always continuous anteriorly and posteriorly; lacking series of mid-ventral radial tube feet.

Dorsal and lateral ossicles: multi-layered perforated ossicles (scales), thick, large surface lumps, canals for tube feet, intergrade with single-layered perforated plates; lacking cups, cupped crosses, rosettes.

Ventral ossicles: small to large single-layered perforated plates, up to 22 perforations, thin to moderately thick, irregularly round to oval, up to 312 μ m long, plate surfaces with abundant fine to medium knobs and rare large peripheral knobs, plate margins knobbed to bluntly spinous (fewer surface and peripheral knobs in plates from small specimens); large specimens have perforated plates with secondary surface developments, intergrading into multi-layered ossicles.

Tentacles lack rosettes.

Colour. Live. Dorsally and laterally grey with off-white; white ventrally.

Preserved. Dorsally and laterally grey, or pale to darker brown with off-white; off-white ventrally.

Distribution. SW Western Australia (Koombana Bay) to SE Tasmania (Port Davey); 4– 37 m.

Remarks. The distinguishing characteristics of Psolidium granuliferum H. L. Clark, 1938 are the absence of a mid-ventral radial series of tube feet on the sole, inconspicuous dorsal and lateral tube feet, coarsely granuliform dorsal and lateral scales, numerous small scales at the base of the large dorsal and lateral scales, and multi-layered ossicles in the sole of larger specimens. In the smallest specimens the sole has perforated plates with fewer knobs, and lacks perforated plates with secondary surface developments and multi-layered ossicles.