Shell up to 1,95 mm in diameter, subplanispiral, spire weakly elevated, very thin and fragile, colourless and transparent, widely umbilicate. Periostracum very thin, smooth and colourless. Protoconch of about 1,75 convex whorls, 233 µm wide. Tip small, rounded and distinctly inrolled. Surface of first half whorl and apertural rim area etched away, elsewhere perfectly smooth. Teleoconch of up to 2,6 slowly expanding, convex whorls, slightly flattened above periphery, evenly rounded from periphery into umbilicus. Smooth apart from faint spiral lines and very fine collabral growth lines. Umbilicus perspective to protoconch, diameter about 26% of adult shell diameter. Aperture almost circular, peristome thin, parietal contact area broad. Animal translucent white. Snout flattened and subquadrate. Cephalic tentacles similar, dorsoventrally flattened, long and narrow, tips spathulate. Operculum absent, opercular lobe very thin.
Known distribution. Off White Island, New Zealand, 1075-1100 m.
Remarks. Xylodiscula eximia differs from X. vitrea in its more evenly convex whorls and narrower umbilicus. Judging from protoconch morphology, like X. eximia, the species probably has planktotrophic larval development.