They publish eight to ten stories every quarter that range from horror to literary, themed on a god or goddess from Greek mythology.
Currently, they’ve issued two theme prompts – Nyx and Typhon:
Nyx, also known as Nux, Nox or simply Night is a primordial Greek goddess who personifies the essence of night and darkness. She is considered to be one of the most powerful divine beings born out of Chaos. She is often depicted as a great black winged spirit or riding in a chariot, trailing stars and bringing the night. Submissions close April 30st 2015.
Nyx, the Night by William-Adolphe Bouguereau
Typhon, a monster anthology vol.1. Dark fantasy and horror fiction submissions for the first volume of their annual horror anthology. They would like new spins on old monster tropes as well as all new monsters. Typhon was a monstrous Storm-Giant, “father of all monsters” who was defeated and imprisoned by Zeus in the pit of Tartarus. Submissions close June 31st 2015.
Payment is 1c per word for unpublished fiction.
See their website as you need to submit online: http://pantheonmag.com/submission-guidelines/
Good luck – may the gods go with you.