The mourning cuttle has a longer body than the giant and red cuttles that you also find in Sydney. The blue lining in the eye and smooth eye sockets are the other indicators of this species.
Argonauta hians, or the winged argonaut, also known as the muddy argonaut or brown paper nautilus, is a species of pelagic octopus. The common name comes from the grey to brown coloured shell.