From the inGeneas Database I have found what appears to be my great-grandfather Berinard (Bernard) McDermott in record ID 585890. Berinard's father was James and his mother was Ann and Berinard's age was 22 in the 1851 census. This all checks with information I had found before.
Short of coming to Ontario (which I may do later) are there on-line resources or researchers in the area who could pursue this further? Berinard may have had siblings Hugh, Mary, James, Margret and Michael. Bernard was married in about 1854 to a Bridget Riley in the Catholic Church. Are there cemetery records in the area of any McDermaids or Rileys?