Whoever gave you the nom de plume of SAGE was right on the mark Heather! You'll be getting Rootschat Member of the Month award. (A visit to Cam'nethan cemetery).
Back to business (I'm trying hard to win the award too - Monica has promised me something nice).
Lindsay & Robertson.
I found a way of photographing this stone but don't ask how I did it

There is an inscription on the back of this stone but I just CANNOT make it out. I will post it and see what better eyes than mine can do. The actual inscription on the front does help as it reads -
"
1826 Here lies the remains of John Lindsay and Jean Robertson his spouse". This implies (in my opinion) that this stone was erected shortly after the remaining one of the died. So it isn't a "marker stone" erected by John & Jean, as is so very often the case but, it has been erected as a memorial. I wonder where the tree on A.....y found out the date of death for Jean? 1826 is the very latest but she may have died years before.
here's the picture, this is the older of the inscriptions, the one on the reverse side is definately a later one.