I just saw this thread. I went and measured Memphis' tail, and it is also 13". The hairs on his tail stay very close to the skin so it looks like a Blues Brothers-esque skinny tie. It turns full feather boa when he's riled up, though (unfortunately, he hasn't let me take a picture of that yet).
He's a pretty lanky cat, and his tail is almost as long as him when he is sitting down.
