Astaresâ–« a River in Pontus causing the sheep that feed near it to give black milk. The heels of most young horses crack, during their exercise, unless this. The heels of most young horses crack, during their exercise, unless this. Super Black - Mouth A Massy Liza Barrington. Astaresâ–« a River in Pontus causing the sheep that feed near it to give black milk.