1911 Encyclopædia Britannica/Agamedes
AGAMEDES, in Greek legend, son of Erginus, king of Orchomenus in Boeotia. He is always associated with his brother Trophonius as a wonderful architect, the constructor of underground shrines and grottos for the reception of hidden treasure. When building a treasure-house for Hyrieus, the brothers fixed one of the stones in the wall so that they could remove it whenever they pleased, and from time to time carried off some of the treasure. Hyrieus thereupon set a trap in which Agamedes was caught; Trophonius, to prevent discovery, cut off his brother’s head and fled with it. He was pursued by Hyrieus, and swallowed up by the earth in the grove of Lebadeia. On this spot was the oracle of Trophonius in an underground cave; those who wished to consult it first offered the sacrifice of a ram and called upon the name of Agamedes. A similar story is told of Rhampsinitus by Herodotus (ii. 121). According to Pindar (apud Plutarch), the brothers built the temple of Apollo at Delphi; when they asked for a reward, the god promised them one in seven days; on the seventh day they died.
Pausanias ix. 37; Plutarch, Consolatio ad Apollonium, 14; Cicero, Tusc. Disp. i. 47.