Shell small, yellowish grey in colour, rather thin, flatly convex, roundly ovate in shape, inequilateral, antero-dorsal edge concave and longer than the convex postero-dorsai; umbo small and prosogyrate ; lunule well defined, narrowly excavate, more sharply developed in the left valve ; escutcheon impressed, long and narrow ; surface sculptured with the close-set concentric lamellae which develop into imbricating scales at the postero-dorsai edge; radial sculpture very fine, only microscopically perceptible, and transverse in the interspaces of the concentric lamellae ; a weak flexure at the postero-dorsai area; two small cardinals in the left valve and one in the right; anterior lateral tooth on the left valve, and the posterior lateral on the right valve; a groove along the anterior and porterior dorsal edges in the right valve ; anterior muscular scar large, somewhat elongate ; the posterior pyriform in shape; pallial line entire ; ventral margin simple. Length 6.6 mm./height 5.9 mm., breadth 1.6 mm.
Type locality: Off Oki Islands in the Japan Sea Distribution : Goto Islands, Kyushu (Soyo-maru St. No. 433, 168 m. in depth) ; off Mishima, Yamaguchi Pref. (Soyo-maru St. No. 481, 143 m. in depth ; No. 486, 139 m. in depth; No. 492, 132 m. in depth) ; off Shimane Pref. (Soyo-maru St. No. 495, 146 m. in depth ; No. 498, 139 m. in depth) ; off Oki Islands and off Yosa Peninsula, Kyoto Pref. (Soyo-maru St. No. 541, 150 m. in depth).The shell of Notomyrtea bractea (Hedley) resembles this new species, but lacks the radiating sculpture. Notomyrtea mayi Gatliff et Gabriel is also alike, but differs in having the widely spaced lamellae on the surface.