Can anyone ID these eggs (snail?)

[phishphood]

So I have 2 types of eggs on the walls of my tank now. There are 2 different types of sacs hanging on the glass now. Just wondering if anyone would be able to ID them. Click the pics for larger images.

1st type: larger eggs, fewer eggs/sac. There are 2 images, one of more mature eggs (can see the larvae in the sac pretty much) and one of newer eggs in the sac. There are maybe 20 of these sacs on the glass.




And a sac of smaller eggs with larger number of eggs/sac. There are literally about a hundred sacs on the glass at this point.




Any help ID'ing them would be great so I know what kind of smaller snails to look for in the tank soon.

 

[GreshamH]

Might help to know what snails and such you do have to help narrow it down

 

[screebo]

I've recently had a snail hatch. In the evening hours, you can spot a very small snail every 1/2" across the entire reef. I'm hoping they are algae mowing types! Except for coral and coralline algae, I'd like my reef to look like half dome!