The Hobbit: The Shire is not mentioned?

The Hobbit was published in 1937

The Fellowship Of The Ring was published 17 years later in 1954

I would imagine he just hadn't come up with the name yet. I did some searching and it does not appear until the "Concerning Hobbits" section in the very very beginning of Fellowship of the Ring.

I do not think it appears in "The Silmarillion" either, but I am still checking into that. It was published in 1977, but that was LONG after it was written. "The Silmarillion" was published by his son after his death. His son edited it, so The Shire might be in it even if the name hadn't been thought of yet, because his son (Christopher) may have added it. I'm still looking into that one. (I'm at work, so I don't have the books here to verify it).

Simply a different reference for the same place. What you have to remember is that Tolkien developed his story the Hobbit, into a great literary and fantasy world. he gave it a history much later on, and as a result, LOTR is more of an "adults fantasy book" and his other big work (and my personal favourite) "The Silmarillion" reads like the Bible. HOWEVER. The Hobbit was written as and essentially is, a children's book.

it might be a myth but I remember reading his initial idea was "a hole in the ground, and something lives in the hole in the ground" and that became a Hobbit. So "And Bilbo lived over the hill" is a particularly childish thing to say if you follow.