Steps to reproduce:
Creative mode
Put Skeleton / Wither Skeleton skull in the hot bar
Select that skull
Press F5 twice
Look under the skull
Related issues
discovered while testing
Attachments
Comments

can confirm
Confirmed.
Confirmed for 1.8pre2

Confirmed for
1.8.4 Might be intended now, as the sides of skulls have now a width
umm, you mean it's fixed
FVbico, I can confirm it's still a problem with the skeleton and wither skeleton skulls, although the creeper, zombie, and player ones are fine.
it renders the insides for me though
You're right, I hadn't noticed that difference. I'll flag it as possibly intended.
So, it should be resolved as fixed now, right?
I'm not sure whether they are supposed to actually have a bottom face or not.
The bug was that, when looking trough the bottom, you could see trough the skull, that's fixed now.
It might be that I missunderstand you, if that's so, can you explain it in other words then?
All the other skulls actually have a bottom face, so it seems like maybe skeleton skulls should as well.
Skeletons have hollow heads because the brains/flesh have been removed, as they are SKELETONS. Makes sense for them to be hollow.
Okay, I'll resolve as intended for now.