a king of Phlagusa, who, in order to avert a pestilence, was commanded by an oracle every year to sacrifice a noble maiden.
He obeyed the command, and had every year a maiden drawn by lot, but did not allow his own daughters to draw lots with the rest. One Mastusius, whose daughter had been sacrificed, was indignant at the king's conduct, and invited him and his daughters to a sacrificial feast. Mastusius killed the king's daughters, and gave their blood in a cup to the father to drink.
The king, on discovering the deed, ordered Mastusius and the cup to be thrown into the sea, which hence received the name of the Mastusian. (Hygin. Poet. Astr.