This is one of the most striking and appropriately named cnidarians of the Pacific Northwest/Salish Sea. Over the past few years I have come across juveniles as small as 50mm (2″) across the bell to animals as large as 60 cm (2 ft) across with copious tentacles as long as 3 metres (10 ft). — all hanging out in relatively shallow coves, The Egg-yolk Jelly is certainly one of my favourite marine animals to photograph. The right angle of sunlight will often filter through and refract the white section of the bell mantle and tentacles in spectacular ways, enabling the yellow gonads at the centre to burn in bright contrast.
Should you wish further information Evergreen University provides an excellent description of the Phacellophora camtschatica as part of their archives for a marine bio course.