Here's a closeup view (below):
We weren't certain what type of egg mass this was, i.e., what type of animal had produced it. A worm? A snail? So we brought a tiny piece back to the lab for a look under the microscope. Here's the first view:
Tbe egg mass was packed with developing larvae! Can you tell what they are?
A couple of the larvae (veligers) had hatched and were crawling on the outside of the egg mass:
Now you can see that this is a tiny gastropod. The shell is very tall. Two black eyespots are visible.
The next image shows a nice view from the side:
We're not sure which species of gastropod this is, but we'll be asking for ideas. If you know, let us know!