It is known only from a series of small vertebrae, with prominent hollow chambers (pneumaticity).

"Captain," said Data, his voice echoing in the hollow chamber.

Your heart is divided into four hollow chambers.

A small skylight has been cut into its dome, while a hole in the floor connects to a hollow chamber.

He had sent away his guards and attendants so that he could be by himself in the hollow chamber.

The hollow chamber was lighted with spotlights from the opposite wall.

From inside his voice returned to him, a dim echo in a hollow chamber.

He turned the Portalight over and inserted them into a hollow chamber.

He called it the hollow chamber, where all true sounds became distorted by echoes.