This map, known as "Harmonia macrocosmica seu atlas universalis et novus, totius universi creati cosmographiam generalem, et novam exhibens", was created by Andreas Cellarius. A scan of the original can be found here.
This sea was labeled on a 21st century-era political map of Earth seen in the remastered "The Cage". This was a Central Intelligence Agency map published either in April 2007 or September 2008.  The difference, which was not noticeable at the resolution of the image from the episode, was the addition of Kosovo, which gained its independence between the releases. The label "Bay of Bengal" was not legible to the viewer.