iPhone with personal hotspot not appearing as a network interface (USB) in the Network preference pane on OS X I have an iPhone 4S running iOS 7.0.2 and a MacBook Pro running OS X 10.8.5.

On the iPhone, I have the tethering option enabled (personal hotspot). I wish to connect via USB, and not over wifi, but somehow I don't have the "USB network interface" (or whatever it is called) on my Mac, so I can't activate it... how can I bring it up?
Click the plus in the bottom-left corner. When you're iPhone is connected, you should be able to add it.