Muscovy laying eggs with balloon like membrane over the entire egg with a tail

[Fullplate farm]

I keep finding eggs with a sac around them and a tail of sorts with fluid in it. Any ideas? I also find the occasional membrane eggs with no shell at all, inspired of a pile of oyster shells available to them. I don't know if it is two different hens or the same one. I suspect two different though. Anyone have experienced the shell in a sac egg?

 

[Buckeye Amy]

Never had this problem. Have you looked up lash egg?