Mesopeplum: Type species: Mesopeplum caroli Iredale 1929.
Shell suborbicular; valves unequal, the right valve deeper than the left; auricles small and prickly, subequal, byssal gape minute, pectinidial teeth small in the immature, obsolete in the adult; sculpture of left valve, five prominent distant compound ribs, composed of three ridges, interspaces broader than the ribs, right valve with five compound ribs of four to eight flattened ribs, with narrower interspaces; interspaces of left valve have four to eight ridges, those of the right being deeper and with two or three ribs therein.
Distribution: Indo-Pacific.
Remarks: A distinguishing feature is the presence of fine concentric threads over the whole surface of the shell.