Africa during Hadrian\'s reign

[Epictetus]

This doesn't directly pertain to your borders question, but if you are interested in the geography of Roman north-west Africa you might try the Peutinger map. It shows two settlments on the coast and seven stations between them. The map dates to centuries later, but you could do some additional research on the names to see if they are relevant to your time period.

Edit: I found something interesting in Strabo, which might help your boundary question:

On sailing further along the coast, we find cities and many rivers, as far as the river Molochath, which is the boundary between the territories of the Mauretanians and of the Masaesyli.

Strabo, 17.3.6