Maxilliped palps are present in adultCyamus ceti,C.scammoniandC.ovalis; absent in adultC.boopis,C.nodosusandC.gracilis; their presence is variable inC.erraticusandC.catodontis. The genusParacyamusis considered a direct synonym ofCyamus.Neocyamusn. gen. is created for the acceptance ofCyamus physeterisPouchet.Cyamus elongatusHiro is shown to be a synonym ofC.boopisLütken andC.boopisvar.physeterisPouchet is a synonym ofC.catodontisMargolis. Further notes on the morphology of several species of cyamids are presented.