20-30m deep, Chiba prefecture, Honshu, 143mm. The species is large, rounded, thin shelled,
with a heavy sculpture made of large ribs, folds on growth marks, and sparse bumps.
The brown surface seems covered with a kind of periostracum.

Wavy crown. The holes are strongly elevated, like the local stratovolcanoes.
At right, Fuji-San, or Klyuchevskaya Skopa.

The surface between the row of holes and the concave columella is large, wide, with a carina.
Spire not often visible in ventral view.