What are these? slighly squidgy, skin like. I dont think they are potatoe as one person thought when i showed them the first speciman on the beach. my folks think they are seaweed roots. I have no idea, sponge or coral. I'm a total beginner at seashore identification. Could you recommend a good comprehensive book for the UK seashore? many thanks. look forward to learning what they are. never seen them before on this beach.