An Indian Legend Talks of a Circumambulation

I had a mail today from Admiral Awati  gently reminding me of an Indian legend that speaks of a circumambulation. And it did come on an opportune date. Here is what he wrote.

"Shiva ( Shankar ) and Parvati ( Gauri ) have two sons, Kartikeya, the Commander in Chief  of the Heavenly Hosts and Ganapati,  popular among the commoners as the harbinger of good things. When they were young and impressionable, there was a competition between the siblings for the affection of their father. Shiva called them together and told them, proceed on a circumambulation of the earth, the one who finishes first will claim my affection. No sooner he heard this filial injunction than the energetic Kartikeya launched himself on his exertions. He came home, panting, from his exertions only to find the languid Ganapati placidly sitting with a wry smile on his face. Kartikeya was amazed to see his brother there before him. Ganapati explained that while brother Kartikeya was rushing about like someone possessed, he, Ganapati, went round their mother, Gauri. Their mother was his world,. his earth. He had, therefore, completed the circumambulation of the earth long before Kartikeya did !

That is the story. The dictum, *AASAMUDRAPARYANTA PRITHVIH, though, is the reality.The earth can be circumambulated  ( circumnavigated ) only by sea."

* Citation needed. Will be glad if anyone can provide me with further details on this. A transliteration in Devnagri will be very much appreciated