cynmaren on Family Tree Circles

I'm searching for the grave site of James W Ferguson (1791- ?) and his wife Matilda Davis Ferguson (1801- ?). They were residents of Canterbury, New Brunswick, Canada in the census years of 1851, 1861, and 1871. I have reason to believe they are buried in the area but can't find any records of their deaths. I have checked every online cemetery & every New Brunswick data base I can think of. By the 1881 census, the oldest son (Samuel) was listed as head of household; the elders had vanished. Is anyone familiar with the local cemeteries or able to search on location? I appreciate any help available.

I'm trying to locate the burial location of my great grandparents, James & Matilda Ferguson. They immigrated to New Brunswick from Ireland in 1833. New Brunswick census records of 1851, 1861, & 1871 show them as residents of Canterbury. I cannot find any death records or cemetery records. James was born in 1791 in Londonderry, Northern Ireland; Matilda was born in 1801 in Ireland.