Comb jellies (ctenophores) have been washing up on local beaches lately. Perhaps you've seen them? They look like little glass marbles on the sand. Each one is ~10-15 mm across.
This species, Pleurobrachia bachei, is often called a Sea Gooseberry. I've written about them before, but it's been a while. To see what these comb jellies look like when they're swimming, and to learn more about them in general, check out these posts:
"Sticky side arms" on 15 July 2013
"A two gooseberry day" on 19 February 2012