Shell small, thin, ovate, yellowish white. Nuclear whorls decollated. The postnuclear whorls are strongly rounded with a decided angulation at the anterior limit of the posterior sinus. The postnuclear whorls are marked by strong, protractively slanting axial ribs which are about half as wide as the spaces that separate them. Of these ribs, 18 are present on the last turn and 15 on the preceding whorl. The spiral sculpture consists of fine incised lines on the shoulder of the turns, that is the sinal area. The shoulder is marked by a spiral cord that renders the axial ribs very strongly nodulose. Anterior to the shoulder, the whorls are marked by strong spiral cords of which 2 are present on the first remaining turn, 3 on the second, and 4 on the third and last turns. Base strongly rounded and marked by the feeble continuations of the axial ribs and 8 spiral threads which become slightly weaker toward the columella. The columella is slender, slightly concave on the left side, and marked by 17 spiral threads. The aperture is pear-shaped. The posterior sinus is moderately deep. Anterior to the posterior sinus the outer lip is protracted and slightly concave on the basal portion. The inner lip is appressed to the columella which it marks as a slight absorption area that extends over the parietal wall. The type, U. S. N. M. No. 226159, was dredged by the U. S. Bureau of Fisheries steamer Albatross at station 3670 in 581 fms. in Monterey Bay on mud bottom. It has 4.5 whorls remaining and measures: Height, 9.9 mm.; greater diameter, 5 mm. NOT FIGURED.
Type: U. S. N. M. No. 538878.

It differs from P. (T.) monterealis Dall in being much shorter, stouter, with more angulated shoulder and in having more distantly spaced ribs.

USA. Pacific coast of California. Monterey vicinity.