Psolidium normani sp. nov.

Figures 2a, b; 5d, f

Psolidium cf. gaini.— O’Loughlin et al., 1994: 552, 554 (non Psolidium gaini Vaney, 1914).

Material examined. Holotype: eastern Antarctica, MacRobertson Shelf, ANARE 1993, Aurora Australis stn 127, 67°16’S 65°26’E, 109-121 m, M. O’Loughlin, 12 Feb 1993, NMV F157400.

Paratypes: Type locality and date, F68661 (1 specimen); F69118 (1); Prydz Bay, Fram Bank, stn 130, 67°32’S 69°02’E, 105–114 m, F68662 (1); ANARE 1991, Aurora Australis stn 100, 67°28’S 68°50’E, 145–150 m, C. C. Lu and T. N. Stranks, 28 Feb 1991, F68111 (1); K. L. Gowlett-Holmes and W. Zeidler, SAM K2220 (1); Enderby Land, BANZARE stn 41, 65°48’S 53°16’E, 193 m, SAM K2341 (2); Adelie Land, BANZARE stn 90, 66°21’S 138°28’E, 640 m (possibly “much shallower”, according to BANZARE records), SAM K2349 (1).

Diagnosis. Psolidium species up to 30 mm long; body elongate, transversely rounded form (preserved), sole narrower than body width; dorsal and lateral tube feet conspicuous, numerous, cover body closely; dorsal and lateral scales inconspicuous.

Sole: outer peripheral single series of smaller tube feet; inner peripheral single series of larger tube feet; lacking mid-ventral (sole) radial series of tube feet.

Dorsal ossicles: predominantly single-layered perforated plates (scales), some secondary layering; up to 4 tube foot canals or marginal indentations per plate; scales up to 800 μ m wide; numerous tube foot support plates, curved, spinous on one side (rarely both sides), marginal spines sometimes bifurcate, up to 19 perforations, up to 136 μ m long; tube foot ‘endplates’ small irregular mesh-like, up to 48 μ m wide, few perforations, irregular marginal projections, not regularly perforated plates.

Sole ossicles: scale-like perforated plates, intergrading with buttons with 4 perforations; plates bluntly to sharply spinous to knobbed on one side, projections sometimes bifurcate; pronounced surface thickenings with ridges or lumps; up to 48 perforations per plate; plates up to 352 μ m long.

Distribution. Eastern Antarctica, Adelie Land; Prydz Bay, Fram Bank; MacRobertson Shelf; Enderby Land; 105–193 m (? 640 m).

Etymology. Named for Mark Norman (Senior Curator, Marine Biology Section, Museum Victoria), with admiration of his enthusiastic engagement with marine invertebrate studies, with gratitude for his personal support, and in recognition of his contribution to collecting from Prydz Bay and Heard I.

Remarks. Psolidium normani sp. nov. is similar externally to P. emilyae sp. nov. (above) and P. gaini Vaney, 1914, but is distinguished by the scale-like plates in the sole and secondary thickening of the dorsal scales.