Identification?

[Donw]

I find objects that look like this on a very regular basis, and I have spent several hours watching some of them, without observing any changes. I am guessing that this is an egg, or cyst. I found this particular specimin in a jar of dried grass and tap water that I set up only three days ago. It is already crawling with Colpoda and other things. Anybody ever seen one of these? Know what it is?



Thanks for looking!