Chiropsalmus quadrumanus
Chiropsalmus quadrumanus, commonly known as the four-handed box jellyfish, is a species of box jellyfish found in the western Atlantic Ocean, the Gulf of Mexico and the Pacific Ocean. The sting is venomous and dangerous to humans, especially children.
Carybdea marsupialis
"Carybdea marsupialis" was once considered a widespread species found in warm oceans around the world. Taxonomic reviews have shown that most of these are other species in the genus "Carybdea", with the true "C. marsupialis" essentially restricted to the Mediterranean Sea. It is the only box jellyfish in this sea. It is pelagic and is present in the upper few metres of the sea.