what are these?

[Ken]

Marie, you got the spelling correct. Foraminiferan. How I remember it was like this, fora mini feran. Actually most named as Homotrema rubrum. I needed to know this because many years ago I had a kindergarten and grade 1 school kids drop in for a field trip to see a living coral aquarium. One of the kid pointed that out to me on a live rock. I couldn't answer her question so I did some research. Grows mostly under rocks in my tanks. Regards Ken