Another theory is that the name might have come from the Latinisation of the Sinhalese henacandaya or "whip snake". That said, neither theory can satisfactorily explain why a species was named in a part of the world where said species did not exist.
From Wikipedia:
The name was first used in the English language in 1768 by V. Jonasson in a colorful description of a large snake found in Ceylon (now Sri Lanka), most likely a reticulated python, Python reticulatus. The account, which explains how the snake constricts and devours tigers, is full of popular misconceptions, but was much read at the time, and so gave rise to the myth of the anaconda of Ceylon.
