Related Clues:

• Prefix meaning ''outside''
• Outer opening?
• ''Skeletal'' prefix
• It means "within"
• Prefix meaning "inside"
• Prefix meaning 'inner'
• Cardial opening
• Within: pref.
• Prefix with ''carp'' or ''biology''
• Morph or scope preceder
• Inner prefix
• Morph or metric preceder
• Ecto's opposite
• Antonym of exo-
• Prefix with -skeleton