I imagine Heine didn't spell "Rhein" as I did in the last posting :(.Erica, I looked up Lorelei in the Britanica, and they claim that the "lor" does come from the German word for to lurk, as I said; but also that "lai" means rock (I don't know in what version of German!). So loreley refers to the rocks lurking--I guess the hidden reefs that did in the ships rather than the mermaid were the lurkers. Her job was to lure rather than to lurk.
Murray