Here is what remains of the statues on the West Pediment.
These sketches, done by Jacques Carrey in 1674, show what the pediment looked like at one time. We can also see from what Elgin brought back that an extreme amount of damage/removal had already been done by the time Elgin arrived.
Athena and Poseidon are in the center. Athena's chariot is on the left, perhaps driven by Nike (Victory) with Hermes, the messenger-god. On the right is Poseidon's chariot driven by his wife Amphitrite and a female messenger, Iris. Other figures further down the gable are various heroes from Athen's past.