1. Thin innermost membranous sac enclosing the developing embryo of higher vertebrates (reptiles, birds and mammals)
   - amnion, amnios

Derived forms: amniotic sacs

Type of: sac

Part of: amniote, fetal membrane

Encyclopedia: Amniotic sac

• Ceratostomataceae
• Ceratostomella
• Ceratostomella ulmi
• Ceratotherium
• Ceratotherium simum
• ceratozamia
• Cerberus
• cercaria
• cercarial
• Cercidiphyllaceae
• Cercidiphyllum
• Cercidiphyllum japonicum
• Cercidium
• Cercidium floridum
• Cercis
• Cercis canadensis
• Cercis occidentalis
• Cercocebus
• Cercopidae
• Cercopithecidae
• Cercopithecus
• Cercopithecus aethiops
• Cercopithecus aethiops pygerythrus
• Cercopithecus aethiops sabaeus
• Cercopithecus talapoin