What's the difference between penteconter and quinquereme?

Penteconter

Definition:

• (n.) A Grecian vessel with fifty oars.

Example Sentences:

Quinquereme

Definition:

• (n.) A galley having five benches or banks of oars; as, an Athenian quinquereme.

Example Sentences:

• (1) He wondered if we could earn our passage out to the Antipodes as oarsmen on a quinquereme.