Another Mystery Lump of Gunge For You To Identify

This lunchtime, to celebrate Canis croxorum’s third birthday, we went to the beach. Actually, we’d have gone to the beach whether it was Canis croxorum’s birthday or not, but that’s not important right now. While we were there I picked up this Interesting Lump of Gunge.

An Interesting Lump of Gunge, earlier today.
It looks like an earthworm threaded through a tough, collagenous outer casing. It could be some sort of tube worm. On the other hand, it could be a piece of weed. I don’t know. OOFTUGs to anyone who can come up with a more positive ID. I do, however, have a good fix on the ID of the interesting pattern covering the casing. Here is a close-up.

A Close-Up.
I reckon that this is a colony of the tunicate Botryllus schlosseri.  It’s amazing to think that such simple squirty things are much more closely related to us – all of us, including Dr R. P. G. of Rotherhithe – than the seemingly more complex worms and shellfish and other stuff one finds on the beach. From humble beginnings, indeed. Makes you think, innit.