We just got back from Port Aransas, and there were some strange animals washed up on the shore. They had lavender-colored snail shells, but the bodies looked nothing like snails. They looked like five or so clear bubbles, connected in a bean shape, with one end at the entrance of the shell. On the underside of the body was three rows of lavender paddle-things, kind of like the fins along the under side of a a shrimp's tail. The creatures came in several different sizes, always with an appropriately-sized shell. I also found some of the bigger ones, only about an inch long, without shells, but seemingly undamaged. If I put one of these in the water, it just floated, like a jellyfish. Ay ideas what these were?