Description

Grayish -white, ornamented with brown periostracum. Spire is form of spiral staircase with fat lib on the shoulder. Umbilicus wide and deep with ridge.

Locality

Japan: Off Sanriku, Off Choshi, Mouth of Tokyo Bay in 100m, Sagami Bay in 30m, Noto, Setonaikai, Kyushu.
Yellow sea.

Original articles of scientific name

1829 Trichotropis unicarinata, Broderip & Sowerby, Zool. Jour., 4 p. 376.

Original of Japanese name

18??　Roppyakukaihin.

Remarks

Rare in the Mouth of Tokyo Bay. Thatcheria mirabilis, Cochlespira pulchella, Mipus vicdani is a spiral staircase-formed shell, too. These shells except Mipus vicdani are found in Mouth of Tokyo Bay.