Mauritania is in Northwest-Africa, which would make it part of both.
Mauritania is part of the geographical North-Africa but NOT the Northern Africa (as a UN subregion)
Mauritania itself is often refereed to as West-Africa. http://en.wikipedia.org/wiki/Mauritania
Bottom line is Mauritania is in West-Africa, but often included in North-Africa. (Which makes the reason for my first sentence. )
So, yes Include Mauritania in your map.
Edited 5/5/2014 22:32:16