Potamides janeae sp. nov.

(Figure 4 (r – t))

Diagnosis

Shell with broadly conical spire. Whorls with three beaded spiral cords. Varices and ventrolateral varix absent. Columella with single fold.

Description

Estimated shell length 15 mm; conical, spire angle about 25°. Protoconch unknown. Spire with at least eight whorls. Whorls flat-sided, sutures thinly incised, recessed. All preserved whorls with three beaded spiral cords. Medial spiral cord narrow, with smallest beads, and close to anterior cord. Beads nodular, spherical, aligned axially in nearly orthocline rectilinear ribs. Base of whorl demarcated by weakly beaded strong spiral cord, with adaxially adjacent, smooth, strong, quadrate spiral cord and weak third spiral cord close to axis. Remainder of base with convex axial threads. Columella with single fold anterior to midpoint. Anterior and posterior canal, if present, and outer lip not preserved.

Etymology

Named in honour of Jane Cody DeVries, mother of the author.

Material

All material from B8771 (type locality). UWBM 107579, holotype, L (9.0), W (5.1); remainder are paratypes: UWBM 107580, L (9.5), W (5.0); UWBM 107581, L (4.1), W (5.0); UWBM 107634, L (4.9), W (4.6); MUSM INV 248, L (8.0), W (5.0); MUSM INV 249, L (8.8), W (4.1)

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Remarks

Specimens of Potamides janeae sp. nov. differ from those of P. henryi sp. nov. by having only three spiral cords, instead of four, and by having unbeaded spiral cords on the base.

Occurrence

Lower Paleogene, Cuenca Member, Caballas Formation, East Pisco Basin, southern Peru.