OK then I'm wondering where you got it from when he gave a clear description:::
There are these white, seemingly stationary, things on the glass in my aquarium. They do not move and appear to be stuck to the glass...meaning when I take a finger nail to them they sort of pop off. They are about the size of a head of a pin and appear to be multiplying, Without actually moving. They barely rise off the glass, meaning there isn't much of a bump that they make. I'm working on a pic but honestly, I can't get a good shot...too small. When looking at them from the bottom, it appears like they have a shell, but are again nearly flush to the glass, but you can see a change in color to what I believe would be their flesh in the center.
Ok been doing some googling and I believe I have nerite snails...they're smallish, and very round and have interesting color patterns on their shells...anyway, someone described their eggs as white sesame seeds on the glass...that is exactly what they look like. I have what I believe are nerites and astreas but no other snails that I have knowingly out in my tank. Again these things don't move at all. So I'm assuming its some sort of egg.