Do you know what these sea creatures are?

Amanda and I went to Stonewall Beach in Martha’s Vineyard.  When we got to the beach, we discovered something new that had washed up onto the shore.  They are small, oval jelly-like creatures that are the size of your fingernail.  Inside of the sea creature, there is a round, blueish body part.  After we saw the sea creatures, I used a net to catch them in the ocean. There were tons of them, so we walked up to the house and got a glass container.  We put some in the container, and we observed them moving.  We took some cool videos that you should check out.  At first we thought they were eggs, but upon further observation my hypothesis is that they are tiny moving jellyfish. We emailed Felix Neck Wildlife Sanctuary to see if they know what they are.  If you know what they are, leave us a comment.  Otherwise, check back in a couple of days to find out.  

At first we thought they might be tiny moon jellies

I catch these in the ocean with my net.

They are about the size of your fingernail.