Shell thin, not translucent, edges of disk finely crenulate. Valves inequilateral, left valve slightly more convex than right one. Left valve 6-7 ribs, right valve 5-6 ribs. Anterior auricles larger than posterior ones. Microsculpture consisting of riblets carrying very fine hollow chambers, giving the shell a shagreen look. When damaged a fine reticulating pattern of lamellae covers the whole valve. Byssal notch very broad, as well as ctenolium. Resilium triangular and strong. Remarks. - The sole differences that Manupecten distinguishes from the Indo-Pacific genus Semipallium Jousseaume, 1928, are the large nodules on the auricles. The number of ribs in Manupecten is distinctly lower, but not different in shape from several Semipallium species. As the shape of the auricles and the microsculpture are identical also, Semipallium is considered a subgenus of Manupecten. Only one recent species of Manupecten s.s, is known, viz. M. pesfelis.