Ancilla to the Pre-Socratic Philosophers: 46. Archippus a...
Ancilla to the Pre-Socratic Philosophers, by Kathleen Freeman, [1948]
Archippus and Lŷsis of Tarentum: middle of fifth century.
Opsimus of Rhêgium: contemporary, or a generation later.
Pythagoreans; no writings survive. Lysis was sometimes credited with having written books ascribed to Pythagoras.