Pollux

The horses of Castor and Pollux. Cyllʹaros and Harʹpagos. Seneca and Claudian give Cyllaros to Castor, but Virgil (Georgic iii.) to Pollux. The two brothers mount it alternately on their return from the infernal regions. Harʹpagos, the horse from Harpaʹgium in Phrygia, was common to both brothers.