Holotype: length 9.9 mm, width 4.2 mm; Largest paratype: length 9.6 mm, width 4.3 mm; Smallest paratype: length 7 mm, width 3.5 mm.

The shell is moderately small (maximum length 12 mm) and lanceolate. The spire is high, consisting of one and one-half nuclear whorls and six or seven dorsoventrally flattened postnuclear whorls. The suture is moderately impressed and partially obscured by varical buttresses. The body bent to the left, and dorsally recurved.
The body whorl bears two relatively weak lateral varices and two minor varices reduced to very weak costae. The fifth and sixth varices seen in the first two or three postnuclear whorls are represented only by varical buttresses on the later whorls. Axial intritacalx sculpture consists of numerous fine striae. Minute transverse tubes may appear aligned and may thus impart a spirally threaded appearance to the shell under high magnification. Other spiral sculpture consists of eight broad cards, visible on the leading edge of each varix.
The shell is translucent yellow-white under a flat-white intritacalx and a pale, yellowish periostracum.
The radular dentition of A. ponderi shows a rachidian tooth of muricine form in which the tentral cusp is broad and long, the lateral cusps are shorter but all broad, and the intermediate cusps are shortest and slender.
Radwin & D'Attilio, 1976. Original description.

Northwestern Australia (Cockburn Sound, Broome) to Southeastern Australia (Woolgoolga, New South Wales).