No haven't got that treasure! You're saying that's on Dragons? Time to go back to it! Yep switch on Endless Loop. Okay you must only have to do it without dying, and I assume from the wording you have to get the extra life. That makes 6/8 treasures if I get that one and you get the Endless Loop one! I'm pretty sure there's none on The Water Source, and none on The Ruined Palace.