Answers are plants or animals found either on the beach, in rocky pools & or in near-shore waters of Britain
11. One of the family of worms that bury in mud but protrude a crown of tentacles when covered by water (3,4)
26. Wildflower-or-animal puzzler: as a snail, it makes a popular food and, fortunately, lives up to its name ; as a blue, woodland bloom, it is neither. (6,10)