P. tavianii has been found in the Sicilian Channel and the Canary Islands at depths of 410-695m. It reaches a maxi¬mum size of approximately 4mm. It has 6.5 solid teleoconch whorls. There is one smooth and one ribbed protoconch whorl. The sculpture consists of 12 costae and 2 spiral cords of equal strength per whorl. Nodules occur where the axial and spiral sculpture intersect. A basal disk is present. The columella is very straight and the base of the aperture is angular.
This recently described species can be distinguished from P. elongata by the stronger axial and radial sculpture and the fact that there are only 2 spiral cords per whorl.