Shell size typical of the genus, adult size up to 4.2 mm; fusiform, elongate. Suture almost straight. Protoconch slightly embedded, consisting of 2.9-3.2 whorls with a sculpture of microscopic correlation. Transition to the teleoconch hardly visible. Teleoconch with 5-6 whorls without any axial or spiral sculpture, except for the basal cords on the body whorl, which ventrally range to just below the upper end of the columella. Outer lip not thickened on the outside, smooth. Inside of the outer lip thickened and denticulate, with 8-9 denticles, upper ones markedly stronger. Above the denticles, a clear posterior canal is present. Columellar callus thickened and semi-detached. Parietal callus weak, but clearly visible. Columella with rim of merged denticles. Further inside the aperture there is a clear incision between the columellar and parietal part. Siphonal canal short, open, slightly recurved. Teleoconch whorls off-white, semi-translucent with a pattern of small, pale brown blotches. Basal cords pale purple with wavy, white axial lines. Apart from this constant pattern, there is a variable pattern of white which can be limited to just some subsutural blotches and a band of blotches at midwhorl in some specimens, to specimens with a pattern of white axial lines. Protoconch white, not translucent. Aperture and columella white, pattern of shell shining through. Holotype height 3.5 mm.

This species can easily be distinguished from other Pyreneola by its unique pattern of pale brown blotches on an off-white background, a feature not seen in any other Pyreneola.

This species has a wide Pacific distribution. Apart from the Marquesas, also known from New Caledonia (MNHN, unpublished data), Vanuatu (MNHN SANTO 2006 stns DB63, DB80 and ZB06) and Hawaii (figured in Severns, 2011: plate 111, fig. 1 as Pyreneola sp). Limited bathymetrical range from intertidal to 20-25 m.