Planaxis suturalis E. A. Smith, 1872. Length, 8 mm; diameter, 3.5 mm. Shell: conic-turbinate, solid; with spiral grooves; white. Spire: protoconch of three spirally keeled, conical, brown whorls; teleoconch of six convex whorls, the last whorl more than two-thirds the height of the spire; suture distinct. Sculpture: spiral sculpture of sharp, deep grooves with wider, rather flat, interspaces. Aperture: ovate; lirate within. Color: white. These planaxids are known only from shells found at depths of from 10 to 30 m.
P. suturalis was described from "the China Seas." The shells are consistently distinct from those of P. labiosa in their white color and sharply defined grooves.