[Legolas]

Ah...I understand. The writings in the two Books of Lost Tales are written from a different perspective than their later versions in The Silmarillion. The entire story from the Silmarillion is being told in the book as a story...a mortal traveller from the future, first named Eriol (later Tolkien changed it to Ælfwine and characterized him as an Englishman from the Middle Ages), has found his way to Tol Eressëa and is being told the story.

This framework is set up in the very first chapter of The Book of Lost Tales titled 'The Cottage of Lost Play.' Eriol finds himself on the island and looking around, finding the cottage where many seem to be gathering for storytelling hour. This is how the stories are told in the Books of Lost Tales, while the "final" version of the Silmarillion (and the other stories) are presented as historical records ultimately collected by Bilbo in his stay with the elves.