Hylas and the Nymphs. To find out more about Hylas, the lover of Heracles, see this Wikipedia article: link; for information about the image: image source.
This famous painting by John William Waterhouse shows Hylas being lured to his doom by the nymphs. Hylas had accompanied Hercules and the other Argonauts on Jason's quest for the Golden Fleece. When Hylas was off by himself, he was abducted by the water nymphs, never to be seen again by Hercules. There is a famous proverb, Hylam vocas, "You're shouting for Hylas" - i.e. you are calling out for something you have lost but which you will never regain, just like Hercules.
You can also find more myths and legends for the week of June 17-23 here. For more information and links to the actual javascript code, see the Myths & Legends Widget Reference Page.