Herodicus was a teacher of
gymnastics and medicine. His own debility led him to devise a strict regimen, which prolonged his life to old age, although he was always sickly.
Cf. Rep. iii. 406 a, Aristot.
Rhet. i. 5. 10, Plut.
de sera ix. He was prob. born in Megara, and afterwards became a citizen of Selymbria on the Propontis.
Σηλυμβριανοί is the form found in the Attic inscriptions of the fifth century, but
Σα_λυ^βρι?́αν in an Attic epitaph from the beginning of the fourth century B.C. (Kumanudes
ἐπιγραφαὶ ἐπιτύμβιοι No. 15.).
Agathocles is mentioned also in Lach. 180 d, and Pythoclides had instructed Pericles in music (acc. to Aristotle in Plutarch Pericles 4). Of the musician Damon, also Pericles's friend, Plutarch says similarly ibid. ἄκρος ὢν σοφιστὴς οὐκ ἔλαθε τῇ λύρᾳ παρακαλύμματι χρώμενος it was no secret that he was a consummate sophist, and used the lyre as a pretext.