Chironex fleckeri, '(Australian) Box Jellyfish'.
These jellyfish usually have four arms, but are most recogniseable by the long long wispy tentacles trailing from the bell. The edges of the domed bell are scalloped.
Aurelia aurita, 'Moon Jellyfish'.
These sea-Jellies have eight 'fluffy' divided arms hanging from the bell, rather than the thin wispy tentacles seen on other jelly fish.
Mastigias papua, 'Spotted Jellyfish'.
Cassiopeia ornata, 'Upside-down Jellyfish'.
Search this website and google: