hydrophyllium

== English == === Etymology === From Ancient Greek ὕδωρ (húdōr, “water”) + φύλλιον (phúllion), diminutive of φύλλον (phúllon, “leaf”). === Noun === hydrophyllium (archaic, zoology) One of the flat, leaf-like, protective zooids covering other zooids of certain Siphonophorae.