This gravestone commemorates Samuel Herries a Kircudbright merchant who died in 1793.
For more information and tour details St Cuthberts Graveyard check out Kirkcudbright History Societies website:
http://www.kirkcudbrighthistorysociety.org.uk/news/kirkcudbright-kirkyard-tours/
Theres also an entry on the Canmore website for the graveyard:
https://canmore.org.uk/site/64069/kirkcudbright-st-cuthberts-church-and-graveyard