EUTHEMIA was a Nymph of the island of Kos (Cos) in the Aegean Sea who insulted the goddess Artemis and was struck down by her arrows.
She was perhaps ones of the Naiades, Nymphai who were thought to die if their springs were dried up. Ineed the passage "snatched away alive by Persephone" suggests that her spring disappeared beneath the earth.
|Perhaps the daughter of a local RIVER-GOD
Pseudo-Hyginus, Astronomica 2. 16 (trans. Grant) (Roman mythographer C2nd A.D.) :
"[Meropes of Kos (Cos)] had a wife, Ethemea, of the race of Nymphae, who was struck with the arrows of Diana [Artemis] when she ceased worshipping her. At last she was snatched away alive by Proserpina [Persephone] to the Land of the Dead."
- Hyginus, Fabulae - Latin Mythography C2nd AD