Possible Clues:

• Bone cavities
• Sinus cavities
• Anatomical cavities
• Cavities in bones
• Bony cavities, anatomically
• Sounds as if one knows where to find them - with the Academician under the insect
• Cavities in insect shown by painter
• Natural cavities in bones
• Holy word leader put out - such will be hollow
• They sound as if they're all for Antrim