Diagnosis: Shell moderate to depressed, distinctly angled at shoulder and periphery; sculptured by fine spiral lirae and weak growth-lines; umbilicus usually somewhat angled, rarely pliculate. Patterned with close set zig-zag brownish axial flames with bolder blotches and bands on shoulder and base.
Description: Shell moderate to depressed (L/D = 0,61-0,68); whorls rather flattened and shouldered; shoulder typically horizontal, but not always so; shoulder angle marked, shell flat or concave between shoulder and periphery; periphery roundly but strongly angled, at or near mid-whorl; base rounded toward periphery, flatter near umbilicus; teleoconch of up to 5,5 whorls; suture of early whorls sunken; otherwise suture level with periphery except on body whorl where it drops below.
Sculpture of numerous fine spiral lirae and faint growth-lines; first and second whorls with 4-6 lirae becoming somewhat obsolete on third, but reappearing during fourth; body whorl with numerous close set lirae; intervals 1-2 times their width; base also lirate, but lirae of varying strength, usually coarser near umbilicus; base sometimes with a broad, smooth spiral band near its centre. Axial sculpture develops from end of third whorl onward, usually in the form of fine, close set growth-lines, some stronger, almost forming pliculae; growth-lines cross lirae which in fresh specimens can produce a fine cancellation; axial sculpture of base weaker peripherally, but often becoming stronger toward umbilicus. Umbilicus deep, moderate to wide; margin generally angled but rarely strongly so, usually without axial pliculae, but occasionally pliculae well developed; margin sometimes marked by 2-3 stronger lirae; interior irregularly lirate. Aperture sub-quadrate to pentagonal, sides unequal; peristome incomplete; outer lip smooth; interior nacreous.
Protoconch: Typically solarielline, diameter 340-360 µm. Colour: Ground colour yellowish-white, adapical surface with close set, fine, dark orangish-yellow to moderate brown (rarely dark brown), somewhat irregular axial flames; shoulder with additional, bolder blotches of similar colour; flames often forming a regular series of )-shaped marks between shoulder and periphery; flames fewer but broader at and below the periphery, often opisthocline; base variously patterned, sometimes plain. Protoconch yellowish-white; early teleo¬conch whorls pale yellow.
Dimensions: largest specimen, length 8,0 mm, diameter 11,8 mm.

The only other local species with such a strongly angled profile is I. kilburni, but that species has a somewhat larger protoconch, much reduced spiral sculpture on the shoulder and a more uniform coloration.

South-Africa: Agulhas Bank west to Atlantic Cape, 146-265 m.