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The brown blob is probably the scale worm Alentia gelatinosa, but I can't see the bits that makes that certain; the limpet looks like Patella vulgata; most of the barnacles are Chthamalus montagui but there is the odd individual of Semibalanus balanoides
Mike (Kendall), I hope you are still coming after all these years. I have offered an ID, not for any other purpose than to satisfy my urge to help with some historical posts. Your analysis is cool but Sophie has probably Post-graduated and left the area.
The subject is a scale worm and it may be Alentia gelatinosa but it's hard to tell. It is certainly quite glossy, always a clue.
But I have simply (and safely) IDd it as Scaleworm - a VERY safe bet.
I am here because I am search all posts with Patella as a subject - I will form a detailed post today.
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