A mushroom cap jellyfish, Rhopilema verrilli, off the coast of New Jersey, USA. The mushroom cap jellyfish has a deep swimming bell without tentacles on it's margin. It is a creamy while colour with darker markings on the sturdy central tentacle structures. It grows up to 20" in diameter and although it has long finger-like appendages hanging from its feeding apparatus, it is not hazardous to people.