Shell small, 5 to 6,5 mm. in length, imperforate, solid, with strong axial costae. Whorls remaining, 44, moderately convex. Color a rather dull brownish-yellow. Spire extended and truncated. Suture deeply impressed. Aperture subovate and nearly holostomatous. Outer lip double, its inner portion a rather thickened and somewhat flaring ridge, the outer portion greatly thickened. Inner lip continuous and much thickened but hardly extending vertically. Columella short and inconspicuous. Sculpture consisting of 14—15 very prominent axial costae (body whorl). These costae terminate at the sutures and seldom oppose evenly the ribs on the whorl above. The costae end at the umbilical region of the body whorl without forming a basal ridge. No spiral sculpture (45x). Operculum thin and corneous with no apparent calcified plate. In young specimens the first 2,5 whorls are smooth: from the third whorl on they become increasingly costate.

The locality, Rio de Janeiro, Brasil, for Gould's T. rostrata is open to question. We have been unable to trace any published record of Truncatella, other than Gould's, from south of Trinidad. Nor are there any records south of Trinidad in the large collections of this genus that we have studied. We have made a careful comparison of Gould's types of T. rostrata with types of Dohrn's T. princeps and can detect no differences.