membranous layer capsule EHDAA:9061 A cover or envelope partly or wholly surrounding a structure. Examples: egg shell, articular capsules, renal capsules[WP]. see also: protective structure surrounding some species of bacteria and fungi. Note that FMA has classes such as Articular capsule that are not subtypes of Capsule (which is undefined in FMA). GO has 'capsule' which is a fungal structure, and 'external encapsulating structure' which is restricted to cells EHDAA:4739 Wikipedia:Capsule_(anatomy) FMA:85272 galen:Capsule