Arm Or Armpit? That Is The Question

Has the British Museum mislabeled a marble fragment from the Acropolis Marbles? The museum says it is a left arm. An expert maintains it is a right arm from another part of the pediment altogether. “That is not an armpit. They have mistaken the little depression between the tendons behind the arm for the armpit itself. It is a right arm. It won’t fit the figure of Iris because it doesn’t come from that figure.”