Yoldia notabilis Yokoyama, 1922 Shell large for this genus, 28.5 mm in length, 14.0 mm in height, very compressed, oblong ovate in shape; umbo small, located at behind middle of dorsal margin; rounded at the anterior margin and acuted at the posterior margin; postero-dorsal margin almost straight; surface covered with yellowish-brown periostracum, and sculptured with concentric growth lines and oblique threads; hinge teeth 24-30 on the anteri or series and 13-18 on the posterior series; mantle sinus deep. Distribution: Huanghai Sea (Yellow Sea); Northern Japan Sea. Ecology: Commonly found on muddy bottom at 30-80 m depth in Huanghai Sea under the Huanghai Sea Cold Water Mass.