'son of Hypnos'.

In some tales, Morpheus is the brother of Hypnos. It's good to remember that there is no received canon with Greek and Roman mythology: just lots of little snippets. The Ceyx tale is also mentioned by Virgil (in passing), and recorded by Pseudo-Apollodorus in the Bibliotheca and Hyginus in his Fabulae. Ceyx' grieving wife's name is related to our word halcyon (as in days): the word meant 'kingfisher' or 'golden' in Greek.

Ceci n'est pas un seing.