Porpita porpita (Linnaeus, 1758)
porpita, blue-button
Porpita porpita

family Porpitidae

Porpita consists of a flat, circular, blue disc which is chambered and gas filled. It acts as a float. It is surrounded by tiny blue tentacles which are not stinging to humans. Porpita does not have a sail. When they wash ashore, they usually do so in large numbers.

Distribution =   found in tropical and subtropical Australian, Indo-Pacific and Atlantic waters.
Max size =   about 1cm across.