Amphistratus
With his brother Rhecas were the charioteers of the Dioscuri. They were believed to have taken part in the expedition of Jason to Colchis, and to have occupied a part of that country which was called after them Heniochia, as ojz/io%os signifies a charioteer.
Pliny calls them Amphitus and Thelchius.
From Smith's Dictionary of Greek and Roman Biography and Mythology