Oh my, those jellies <3 Sea nettles if I'm not mistaken, their bells have those lovely dots of colour around the edge and they have those beautiful long oral arms and stinger tentacles. (they can pack a punch though need to wear gloves if you have your hands near those babies.
Yes I love jellyfish which is what dragged me in to this one, the selection you have chosen though does show a clear progression, each image getting cleaner lines as you have refined your techniques.