Shell large, massive, conical, imperforate; spire elevate, later whorls becoming subscalar. Whorls seven. Colour a uniform dull brick-red, except a brilliant cadmium-orange ring round the aperture. Sculpture: the earlier whorls are strongly radiately plicate below the sutures; periphery armed with short, broad, downwardly directed spines becoming obsolete towards the aperture; on the penultimate whorl they number sixteen. Close spiral cords densely beset with imbricating scales cover the surface of the shell; above there are ten cords carrying more distant hooded scales obliquely connected with those above and below. On the base there are also ten cords with more crowded scales. Base flattened. Aperture very oblique, subcircular, within and upon the columella pearly; a narrow inner margin to the lip continuous with an axial callus pad is bright cadmium-orange. Operculum pale orange, oblong, nucleus subterminal, hollow medially between two ribs, one of which rises proximally into a heavy callus mound. Height 87 mm.; major diam. 92 mm.; minor diam 80 mm.

DIAGNOSIS. Shell: Whorls convex, with scaly, nodular sculpture and medium to short peripheral spines. Peripheral angulation spinose, sharp in early spire whorls, at lower 1/3-1/4 , becomes rounded on later whorls, weak and rounded in large shells. About 10-15 short spines on last whorl of medium sized shells; up to 22 in large shells (such as the holotype). Spines relatively long in juveniles. A second angle just below periphery also becomes rounded on large shells. Eight-nine squamose spiral ribs on base and 10 on side of penultimate whorl; lower spirals on sides of whorls very oblique and pass laterally on to the peripheral spines. One spiral between peripheral and basal angles, the latter having an additional spiral cord. Basal callus narrow, covering about a quarter of base, bright orange; columella white. Surface purplish-red, brick-red or dull orange, often with a white and pale olive marbled band in the centre of the upper surface of the whorls of immature shells.
Operculum: Oval, with large marginal rib and central spiral depression as in 6. rugosa, but more elongate than that species. Very similar to that of Lithopoma (Cookia) sulcata, which, however, is white, not pinkish-orange as in aureola.
DIMENSIONS. Largest shell seen (C. 37246): height 88 mm, diameter 98 mm. Holotype: height 87 mm, diameter 92 mm.
TYPE LOCALITY. S. of Masthead Island, Capricorn Group, Queensland, 37 m.
HOLOTYPE. AM, C. 18807.
OTHER MATERIAL EXAMINED, (all AM; numbers in brackets show number of specimens). Queensland: Gillett Cay, Swain Reefs, 69 m, C. 72698 (1); Northwest Is., Capricorn Group, C. 72695 (1); Heron Is., C. 72693 (1); 27 km E. of Heron Is., 55 m, C. 72690 (1); Masthead Reef, C. 37246 (1); off Bundaberg, C. 72697 (2); off Burnett Heads, C. 72694 (4); prawn trawl south of Fraser Is., C. 72693 (3); Tin Can Bay, C. 62499 (3);Off Wide Bay, 46 m, C. 72692 (2), 55 m, C. 72703 (1); trawled in Wide Bay, C. 81962 (2); Off Jumpin Pin Bar, near Southport, 31 m, C. 63161 (2); off Southport, C. 72689(1); New South Wales: off Tweed Heads, northern N.S.W., 55 m, C. 72691 (3).
Small and medium-sized shells are similar to B. modesta (Reeve), from which they differ in their brighter colour, longer spines, narrower callus pad, and more strongly sculptured operculum. Still more alike is B. johnstoni (Odhner), which has closely similar spination, but has a widely spread basal callus and a convex, centrally granular operculum.

In size and general appearance it is comparable to A. sulcatum Martyn from New Zealand, and may be classed as a second member of the subgenus Cookia. The subscalar whorls, peripheral thorns and orange mouth of A. aureolum distinguish it.

Australia. Queensland. Mast Head Reef, Capricorn Group.