Jellyfish invasion

Not sure what these species are. There was an interesting article in last week's Japan Times about the invasion of Nomura jellyfish, the worlds largest. The article is here

The one in the photo above was pretty small, and it was trapped in a tide pool.

Just off the rocks was this much larger one, about 50cms wide. While sailing off the Shimane coast I have seen some monsters more than 1 meter across, but apparently they can grow to 2 meters.