Diagnosis: Shell very depressed, sublenticular; smooth and glossy but with some spiral lirae at periphery; no subsutural pliculae or coronations; shoulder absent. Umbilicus pliculate when young, smooth in adult; margin angular.
Description: Shell very depressed (L/D = 0,54-0,58), sublenticular, spire low; whorls flattened, somewhat angular at the periphery, shoulder absent, suture not sunken, periphery at approximately mid-whorl; teleoconch of up to 4,5 whorls. Sculpture weak; first whorl with ca 5 spiral lirae which become obsolete and disappear on second whorl; shell mostly smooth and glossy with fine, curved, prosocline growth-lines; some fine spiral lirae persist at periphery. Umbilicus wide, deep, steep-sided, margin angular; juveniles with distinct umbilical pliculae, becoming smooth with growth. Aperture rather D-shaped, indented by parietal region; peristome incomplete; outer lip smooth, prosocline; interior nacreous. Protoconch : Solarielline, but with terminal lip slightly expanded; diameter 290-300 µm.
Colour: Ground colour white to yellowish-white; apical surface almost covered by zig-zag radial bands in various shades of brown; alternately dark and light, V-shaped marks form two distinct spiral bands; radial bands are fewer, but broader at periphery and continue onto base and into umbilicus; bands usually interrupted just below the periphery. Some pink/green iridescence. Dimensions: Holotype, length 5,6 mm, diameter 10,0 mm (= largest specimen). Radula as in I. laevissima, but rachidian and inner laterals with slightly fewer, coarser denticles; exposed surface of cusps with inter-denticular grooves.

Moderately to rather tall for genus (H up to 6.8 mm, W to 13.1 mm), height 0.47-0.61 xwidth, about 1.7xaperture height; much wider than high, shape sublenticular, thin-shelled, glossy; spire depressed, periphery subangular; umbilicus very broad, deep. Protoconch ca. 250-300 um wide, 1.25 whorls, rounded, with about 5 weak spiral and with terminal lip slightly expanded. Teleoconch up to 4.8 weakly convex to nearly flat whorls, without shoulder; whorls smooth except first whorl; weak growth lines on last whorls. Suture impressed, not canaliculated. First whorl convex, sculptured with 5-6 spiral cords appearing immediately; cords more or less equally spaced; abapical cords vanishing near end of whorl; very fine axial threads between cords. At end of second whorl, all cords vanished and axial threads disappearing, leaving surface nearly smooth with weak, fine prosocline growth-lines. On last whorl, some very weak, low, thin abapical cords near periphery. Aperture subcircular; peristome incomplete; outer and inner lip thin; inner lip with weak basal thickening against umbilical rim. Base moderately convex, smooth. Umbilicus broad (diameter 25-28% of shell width), central, with perspective to apex, with angulate rim; steep-sided wall with very thin axial threads and without spiral cords inside; axial pleats visible on early whorls, but not body whorl.
Colour: Teleoconch white to yellowish-white, with brown zig zag radial bands (sometimes diffuse) forming usually two distinct spiral bands; base pale or white, with similar zig zag bands.
Operculum: Corneous, multispiral with central nucleus, brown.

Similar in colour and lack of sculpture to I. laevissima, but much more depressed and with a smaller protoconch. Also resembles Solariella zaccaloides Schepman, 1908, but lacks umbilical pliculae in the adult and subsutural coronations.
Generally constant in shell height, whorl profile and colour pattern. Found only in relatively dense, rather glutinous substrata for which the flattened shell is no doubt an adaptation. Some MNHNP specimens from off Reunion Island are very similar.

Distribution: South- Africa. Known only from off Durban, 165-270 m (living in fine, slightly muddy sand).