Thank you for your responses.
It seems it's not quite as clear cut as I was hoping!
I think using your definition Tom, they would appear to be far from natural then. Afraid I can't fathom out how the links are being labelled ameliavargo.... I'm still trying to understand how to decipher the data that moz is providing me.
It's interesting because if this is in fact a valid "loophole" to gain links then it seems pretty effective! Looking at my example, this method is generating thousands of links for the individual businesses listed within the internal directory which I'm imagining must do wonders for SERP's.
So is it fair to assume that the reason this does not get picked up by Google is because all of the links are of businesses in the same field of work? I guess what I'm asking in effect is, how does Google go about assessing the integrity of the links?