Phascolosoma cf. agassizii in Steinbeck & Ricketts, 1941: 346,

as Physcosoma cf. agassizii (in debris of Pocillopora, Cabo Pulmo reef; Baja California Sur; under boulders, Puerto Escondido, Baja California Sur; in rocks, San Carlos Bay, Baja California Sur; under boulders, Puerto Refugio, Baja California, Mexico).