Shell large, 69.1 mm in height, 85.7 mm in length and 59.5 mm in breadth, inflated, obliquely ovate, rather inequivalve; umbonal part swollen but not strongly elevated, sides slightly angulated at the upper part, anterior side rounded and posterior obliquely truncated, ventral margin roundly curved; surface sculptured with about 41 - 43 flat and smooth radial ribs and covered with a brown epidermis.
Distribution: Bohai Sea of China, Huanghai Sea( Yellow Sea), East China Sea; Japan; Korea.
Ecology: Live in soft muddy or muddy sand bottom from subtidal zone to several tens meters depth, common in northern China coasts. The flesh of this species is very delicious as food.