ID help please. Animal, vegetable or mineral?

[kryppy]

Collected this a few months back in the Keys. It hasn't done much.

 

[Aquabucket]

Its a dead paper-like skeleton. I also collected a similar one from the Fl. gulf years ago. I had to partially bury it in the sand to stop it from floating around.

Here is a small pic:

I never had a clue as to what it was when alive though ~ just thought it made a nice decoration for my small tidewater tank

 

[LeslieH]

They're empty egg cases, possibly from a snail

 

[Aquabucket]

That makes sense!