Hi Rich, thanks for that, yes, this is precisely the problem. RB sent me a link where it said they were Ptolemaic era, but this article suggests they may be older..or may not be.

The info could be as noted from the dictionary of greek and roman geography 1857 by william smith, but I was hoping for a more up to date academic source to work from.

Dave L

"It is not possible to determine at what period, if indeed at any, the Heptanomis was regarded as an integral third of Egypt. About the number of its nomes there can be no question; but which, at any given era, were the seven principal nomes, it is less easy to decide

The Journal of Ancient Egyptian Architecture JAEA:
[egyptian-architecture.com]
[glasgow.academia.edu]
[egyptology-scotland.squarespace.com]
Dave's Archaeology Homepage:
[arkysite.wordpress.com]