P. cerithielloides has been found in a single locality in the eastern Atlantic at a depth of 1000-2000m; recently a new, adult specimen, has been found in the Central Tyrrhenian Sea, at a depth of about 450m. It reaches a maximum size of about 4mm. This is a solid species with 5 convex teleoconch whorls. The suture is deeply impressed. It appears to have 20-25 costae as well as about 6 raised spiral lines per whorl. A basal ridge is present with about 3 spiral threads below it. The aperture is oval and the outer lip is thin.
It can be separated from P. praelonga by the rounded whorls and strongly cancellate sculpture. The specimen illustrated is the one coming from the Tyrrhenian Sea, and is in the Smriglio collection.