Shell minute, naticoid, with the spire moderately elevated, shining, white; nuclear whorls about 2, smooth, rounded; postnuclear whorls 2,5 , evenly rounded, smooth except for microscopic axial striations which are most distinct immediately below the suture; periphery and base rounded; outer lip slightly thickened; inner portion of basal lip and inner lip sharply raised, continuing over the body as a raised callus, retractively waved at the periphery; a callus tongue begins at the middle of the basal lip, curves over the base and terminates abruptly at the edge of the small open umbilicus. The type measures: maximum diameter, 2.0 mm.; height 1.1 mm.
Holotype near Port Parker, Costa Rica, dredged in 12 fathoms (22 meters), shelly mud.
This species is not typical of the genus Teinostoma but seems referable to that genus rather than to any other recorded from the west coast. The species here described evidently is somewhat like the unfigured Teinostoma bibbiana Dall from San Diego, California, which is described as having "only a small linguiform pad behind the pillar lip."