Protoconch of 2 smooth, rounded whorls, with indistinct transition to teleoconch. Spire convex in outline, whorls rounded, aperture 2/5 shell length. Axial and spiral sculpture absent, except for strong spiral cords and grooves at base of body whorl. Outer lip thickened externally, with weak sinus posteriorly opposite callus pad on parietal wall; lip thickened internally on upper half; lip with 2-7 denticles internally, stronger on the thickened part. Columella callus sharp-edged, with 3 denticles, sometimes very weak. Siphonal notch deep, narrow. Coloured with a distinctive pattern of spiral rows of squarish white patches superimposed on fawn or tan spiral bands; body whorl with 3 background tan bands - below suture, at midwhorl and at base. Shell covered with thin, brown periostracum when fresh.
Size: Up to 10 mm in length, commonly 6-8 mm.

Pseudamycla miltostoma (Tension-Woods, 1876) occurs in southern Australia, but is not known from NSW. It has distinct spiral grooves, at least immediately below the suture, and a paler colouration.

Endemic to Australia: Brunswick Heads, NSW, around southern Australia to Cape Naturaliste, south-western WA, including Tasmania.
Habitat: On algae in the intertidal and subtidal, down to 20 m. Common.