taxonomic term needed

[Robin Panza]

> and some of what
>appear to be essentially a single vesicle with columnar supports
>maintaining the separation between the layers above and below it.
>
>Thanks
>R E Hill
>REhill at ix.netcom.com

This sounds like the structure of a bird's braincase--2 thin layers of bone
kept separate by columns of bone.  In birds, this is called pneumatized, and
the process of construction is called pneumatization.  Would that work?

Robin Panza
Section of Birds                        panzar at clp2.clpgh.org
Carnegie Museum of Natural History