Abstract
The following three species of the Boreal-type brachiopod genus Yakovlevia are described from the Middle Permian (Kungurian to Ufimian) of the Hida Gaien (=Hida Marginal) and South Kitakami Belts, Japan : Y. kaluzinensis Fredericks, Y. mammata (Keyserling) and Y. mammatiformis (Fredericks). The occurrence of Yakovlevia together with various Boreal-and Tethyan-type brachiopods in the Middle Permian of the two belts suggests that these regions were probably a continental shelf at the eastern margin of the Sino-Korean block in Middle Permian time.
