What's This?

Hopefully somebody can identify this odd creature. Thousands of them were washed up among the weed on local North Mayo beaches during the strong north winds earlier this week:

It's about 2.5 inches long, an inch wide, and has an opaque "fin" about an inch high on top. The body was rubbery and gelatinous, a strange opaque blue tint, and there was a brown streak in the middle of it, lengthways. It also has ridges round it that look like the growth rings on a shell.

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Beleave it or not the are a form of jellyfish nick named by the wind sailors .

A "by-the-wind sailor" or Velella velella by it's scientific name, it is a species of jellyfish. Generally harmless to humans, however people can react to certain toxins in different ways. Don't touch your face or eyes after handling and itching may occur on areas of skin that have been in contact with the Velella velella.

Thanks!

Loads do these are around brandon bay at the moment too.

Story on sky news today about them, apparently billions of them have been washed up along the North American West coast.

Saw th in North Spain a few years ago!