In most cases, Latin is used sparingly in 17th- and 18th-century New England epitaphs. "Memento Mori" and "Fugit Hora" are common enough, as are individual words such as "Obiit" and "Aetatis," but if you see an epitaph that is entirely written in Latin, it probably belongs to a minister, doctor, professor, or other eminent citizen.
This gravestone belongs to Rev. John Barnard of Marblehead, MA. Barnard, a friend and sometimes rival of the Mathers, is remembered chiefly for writing an autobiography (excerpts available here).
As I have noted before, I am no classicist, so the best I can say here is that I think that "Peracto Hac Vita" means something along the lines of "Finished this Life." If you have a better translation, please leave it in the comments.
Rev. John Barnard, Marblehead, MA, 1770